WorldWideScience

Sample records for ground based radar

  1. Bridge Testing With Ground-Based Interferometric Radar: Experimental Results

    International Nuclear Information System (INIS)

    Chiara, P.; Morelli, A.

    2010-01-01

    The research of innovative non-contact techniques aimed at the vibration measurement of civil engineering structures (also for damage detection and structural health monitoring) is continuously directed to the optimization of measures and methods. Ground-Based Radar Interferometry (GBRI) represents the more recent technique available for static and dynamic control of structures and ground movements.Dynamic testing of bridges and buildings in operational conditions are currently performed: (a) to assess the conformity of the structure to the project design at the end of construction; (b) to identify the modal parameters (i.e. natural frequencies, mode shapes and damping ratios) and to check the variation of any modal parameters over the years; (c) to evaluate the amplitude of the structural response to special load conditions (i.e. strong winds, earthquakes, heavy railway or roadway loads). If such tests are carried out by using a non-contact technique (like GBRI), the classical issues of contact sensors (like accelerometers) are easily overtaken.This paper presents and discusses the results of various tests carried out on full-scale bridges by using a Stepped Frequency-Continuous Wave radar system.

  2. Bridge Testing With Ground-Based Interferometric Radar: Experimental Results

    Science.gov (United States)

    Chiara, P.; Morelli, A.

    2010-05-01

    The research of innovative non-contact techniques aimed at the vibration measurement of civil engineering structures (also for damage detection and structural health monitoring) is continuously directed to the optimization of measures and methods. Ground-Based Radar Interferometry (GBRI) represents the more recent technique available for static and dynamic control of structures and ground movements. Dynamic testing of bridges and buildings in operational conditions are currently performed: (a) to assess the conformity of the structure to the project design at the end of construction; (b) to identify the modal parameters (i.e. natural frequencies, mode shapes and damping ratios) and to check the variation of any modal parameters over the years; (c) to evaluate the amplitude of the structural response to special load conditions (i.e. strong winds, earthquakes, heavy railway or roadway loads). If such tests are carried out by using a non-contact technique (like GBRI), the classical issues of contact sensors (like accelerometers) are easily overtaken. This paper presents and discusses the results of various tests carried out on full-scale bridges by using a Stepped Frequency-Continuous Wave radar system.

  3. Foundation Investigation for Ground Based Radar Project-Kwajalein Island, Marshall Islands

    Science.gov (United States)

    1990-04-01

    iL_ COPY MISCELLANEOUS PAPER GL-90-5 i iFOUNDATION INVESTIGATION FOR GROUND BASED RADAR PROJECT--KWAJALEIN ISLAND, MARSHALL ISLANDS by Donald E...C!assification) Foundatioa Investigation for Ground Based Radar Project -- Kwajalein Island, Marshall Islands 12. PERSONAL AUTHOR(S) Yule, Donald E...investigation for the Ground Based Radar Project -- Kwajalein Island, Marshall Islands , are presented.- eophysical tests comprised of surface refrac- tion

  4. On reconciling ground-based with spaceborne normalized radar cross section measurements

    DEFF Research Database (Denmark)

    Baumgartner, Francois; Munk, Jens; Jezek, K C

    2002-01-01

    This study examines differences in the normalized radar cross section, derived from ground-based versus spaceborne radar data. A simple homogeneous half-space model, indicates that agreement between the two improves as 1) the distance from the scatterer is increased; and/or 2) the extinction...

  5. A hardware-in-the-loop simulation program for ground-based radar

    Science.gov (United States)

    Lam, Eric P.; Black, Dennis W.; Ebisu, Jason S.; Magallon, Julianna

    2011-06-01

    A radar system created using an embedded computer system needs testing. The way to test an embedded computer system is different from the debugging approaches used on desktop computers. One way to test a radar system is to feed it artificial inputs and analyze the outputs of the radar. More often, not all of the building blocks of the radar system are available to test. This will require the engineer to test parts of the radar system using a "black box" approach. A common way to test software code on a desktop simulation is to use breakpoints so that is pauses after each cycle through its calculations. The outputs are compared against the values that are expected. This requires the engineer to use valid test scenarios. We will present a hardware-in-the-loop simulator that allows the embedded system to think it is operating with real-world inputs and outputs. From the embedded system's point of view, it is operating in real-time. The hardware in the loop simulation is based on our Desktop PC Simulation (PCS) testbed. In the past, PCS was used for ground-based radars. This embedded simulation, called Embedded PCS, allows a rapid simulated evaluation of ground-based radar performance in a laboratory environment.

  6. Ground penetrating radar

    CERN Document Server

    Daniels, David J

    2004-01-01

    Ground-penetrating radar has come to public attention in recent criminal investigations, but has actually been a developing and maturing remote sensing field for some time. In the light of recent expansion of the technique to a wide range of applications, the need for an up-to-date reference has become pressing. This fully revised and expanded edition of the best-selling Surface-Penetrating Radar (IEE, 1996) presents, for the non-specialist user or engineer, all the key elements of this technique, which span several disciplines including electromagnetics, geophysics and signal processing. The

  7. Submillimetric motion detection with a 94 GHz ground based synthetic aperture radar

    OpenAIRE

    Martinez Cervera, Arturo; Lort Cuenca, Marc; Aguasca Solé, Alberto; Broquetas Ibars, Antoni

    2015-01-01

    The paper presents the validation and experimental assessment of a 94 GHz (W-Band) CW-FM Radar that can be configured as a Ground Based SAR for high resolution imaging and interferometry. Several experimental campaigns have been carried out to assess the capability of the system to remotely observe submillimetric deformation and vibration in infrastructures. Peer Reviewed

  8. Mobile Ground-Based Radar Sensor for Localization and Mapping: An Evaluation of two Approaches

    Directory of Open Access Journals (Sweden)

    Damien Vivet

    2013-08-01

    Full Text Available This paper is concerned with robotic applications using a ground-based radar sensor for simultaneous localization and mapping problems. In mobile robotics, radar technology is interesting because of its long range and the robustness of radar waves to atmospheric conditions, making these sensors well-suited for extended outdoor robotic applications. Two localization and mapping approaches using data obtained from a 360° field of view microwave radar sensor are presented and compared. The first method is a trajectory-oriented simultaneous localization and mapping technique, which makes no landmark assumptions and avoids the data association problem. The estimation of the ego-motion makes use of the Fourier-Mellin transform for registering radar images in a sequence, from which the rotation and translation of the sensor motion can be estimated. The second approach uses the consequence of using a rotating range sensor in high speed robotics. In such a situation, movement combinations create distortions in the collected data. Velocimetry is achieved here by explicitly analysing these measurement distortions. As a result, the trajectory of the vehicle and then the radar map of outdoor environments can be obtained. The evaluation of experimental results obtained by the two methods is presented on real-world data from a vehicle moving at 30 km/h over a 2.5 km course.

  9. Cross Validation of Rain Drop Size Distribution between GPM and Ground Based Polarmetric radar

    Science.gov (United States)

    Chandra, C. V.; Biswas, S.; Le, M.; Chen, H.

    2017-12-01

    Dual-frequency precipitation radar (DPR) on board the Global Precipitation Measurement (GPM) core satellite has reflectivity measurements at two independent frequencies, Ku- and Ka- band. Dual-frequency retrieval algorithms have been developed traditionally through forward, backward, and recursive approaches. However, these algorithms suffer from "dual-value" problem when they retrieve medium volume diameter from dual-frequency ratio (DFR) in rain region. To this end, a hybrid method has been proposed to perform raindrop size distribution (DSD) retrieval for GPM using a linear constraint of DSD along rain profile to avoid "dual-value" problem (Le and Chandrasekar, 2015). In the current GPM level 2 algorithm (Iguchi et al. 2017- Algorithm Theoretical Basis Document) the Solver module retrieves a vertical profile of drop size distributionn from dual-frequency observations and path integrated attenuations. The algorithm details can be found in Seto et al. (2013) . On the other hand, ground based polarimetric radars have been used for a long time to estimate drop size distributions (e.g., Gorgucci et al. 2002 ). In addition, coincident GPM and ground based observations have been cross validated using careful overpass analysis. In this paper, we perform cross validation on raindrop size distribution retrieval from three sources, namely the hybrid method, the standard products from the solver module and DSD retrievals from ground polarimetric radars. The results are presented from two NEXRAD radars located in Dallas -Fort Worth, Texas (i.e., KFWS radar) and Melbourne, Florida (i.e., KMLB radar). The results demonstrate the ability of DPR observations to produce DSD estimates, which can be used subsequently to generate global DSD maps. References: Seto, S., T. Iguchi, T. Oki, 2013: The basic performance of a precipitation retrieval algorithm for the Global Precipitation Measurement mission's single/dual-frequency radar measurements. IEEE Transactions on Geoscience and

  10. Summer planetary-scale oscillations: aura MLS temperature compared with ground-based radar wind

    Directory of Open Access Journals (Sweden)

    C. E. Meek

    2009-04-01

    Full Text Available The advent of satellite based sampling brings with it the opportunity to examine virtually any part of the globe. Aura MLS mesospheric temperature data are analysed in a wavelet format for easy identification of possible planetary waves (PW and aliases masquerading as PW. A calendar year, 2005, of eastward, stationary, and westward waves at a selected latitude is shown in separate panels for wave number range −3 to +3 for period range 8 h to 30 days (d. Such a wavelet analysis is made possible by Aura's continuous sampling at all latitudes 82° S–82° N. The data presentation is suitable for examination of years of data. However this paper focuses on the striking feature of a "dish-shaped" upper limit to periods near 2 d in mid-summer, with longer periods appearing towards spring and fall, a feature also commonly seen in radar winds. The most probable cause is suggested to be filtering by the summer jet at 70–80 km, the latter being available from ground based medium frequency radar (MFR. Classically, the phase velocity of a wave must be greater than that of the jet in order to propagate through it. As an attempt to directly relate satellite and ground based sampling, a PW event of period 8d and wave number 2, which appears to be the original rather than an alias, is compared with ground based radar wind data. An appendix discusses characteristics of satellite data aliases with regard to their periods and amplitudes.

  11. Quantifying snow and vegetation interactions in the high arctic based on ground penetrating radar (GPR)

    DEFF Research Database (Denmark)

    Gacitúa, G.; Bay, C.; Tamstorf, M.

    2013-01-01

    Arctic in Northeast Greenland. We used ground penetrating radar (GPR) for snow thickness measurements across the Zackenberg valley. Measurements were integrated to the physical conditions that support the vegetation distribution. Descriptive statistics and correlations of the distribution of each...

  12. Low velocity target detection based on time-frequency image for high frequency ground wave radar

    Institute of Scientific and Technical Information of China (English)

    YAN Songhua; WU Shicai; WEN Biyang

    2007-01-01

    The Doppler spectral broadening resulted from non-stationary movement of target and radio-frequency interference will decrease the veracity of target detection by high frequency ground wave(HEGW)radar.By displaying the change of signal energy on two dimensional time-frequency images based on time-frequency analysis,a new mathematical morphology method to distinguish target from nonlinear time-frequency curves is presented.The analyzed results from the measured data verify that with this new method the target can be detected correctly from wide Doppler spectrum.

  13. The Monitoring Case of Ground-Based Synthetic Aperture Radar with Frequency Modulated Continuous Wave System

    Science.gov (United States)

    Zhang, H. Y.; Zhai, Q. P.; Chen, L.; Liu, Y. J.; Zhou, K. Q.; Wang, Y. S.; Dou, Y. D.

    2017-09-01

    The features of the landslide geological disaster are wide distribution, variety, high frequency, high intensity, destructive and so on. It has become a natural disaster with harmful and wide range of influence. The technology of ground-based synthetic aperture radar is a novel deformation monitoring technology developed in recent years. The features of the technology are large monitoring area, high accuracy, long distance without contact and so on. In this paper, fast ground-based synthetic aperture radar (Fast-GBSAR) based on frequency modulated continuous wave (FMCW) system is used to collect the data of Ma Liuzui landslide in Chongqing. The device can reduce the atmospheric errors caused by rapidly changing environment. The landslide deformation can be monitored in severe weather conditions (for example, fog) by Fast-GBSAR with acquisition speed up to 5 seconds per time. The data of Ma Liuzui landslide in Chongqing are analyzed in this paper. The result verifies that the device can monitor landslide deformation under severe weather conditions.

  14. Forward modeling of seepage of reservoir dam based on ground penetrating radar

    Directory of Open Access Journals (Sweden)

    Xueli WU

    2017-08-01

    Full Text Available The risk of the reservoir dam seepage will bring the waste of water resources and the loss of life and property. The ground penetrating radar (GPR is designed as a daily inspection system of dams to improve the existing technology which can't determine the actual situation of the dam seepage tunnel coordinates. The finite difference time domain (FDTD is used to solve the Yee's grids discreatization in two-dimensional space, and its electromagnetic distribution equation is obtained as well. Based on the actual structure of reservoir dam foundation, the ideal model of air layer, concrete layer, clay layer and two water seepage holes is described in detail, and the concrete layer interference model with limestone interference point is established. The system architecture is implemented by using MATLAB, and the forward modeling is performed. The results indicate that ground penetrating radar can be used for deep target detection. Through comparing the detection spectrum of three kinds of frequency electromagnetic wave by changing the center frequency of the GPR electromagnetic wave of 50 MHz, 100 MHz and 200 MHz, it is concluded that the scanning result is more accurate at 100 MHz. At the same time, the simulation results of the interference model show that this method can be used for the detection of complex terrain.

  15. MetaSensing's FastGBSAR: ground based radar for deformation monitoring

    Science.gov (United States)

    Rödelsperger, Sabine; Meta, Adriano

    2014-10-01

    The continuous monitoring of ground deformation and structural movement has become an important task in engineering. MetaSensing introduces a novel sensor system, the Fast Ground Based Synthetic Aperture Radar (FastGBSAR), based on innovative technologies that have already been successfully applied to airborne SAR applications. The FastGBSAR allows the remote sensing of deformations of a slope or infrastructure from up to a distance of 4 km. The FastGBSAR can be setup in two different configurations: in Real Aperture Radar (RAR) mode it is capable of accurately measuring displacements along a linear range profile, ideal for monitoring vibrations of structures like bridges and towers (displacement accuracy up to 0.01 mm). Modal parameters can be determined within half an hour. Alternatively, in Synthetic Aperture Radar (SAR) configuration it produces two-dimensional displacement images with an acquisition time of less than 5 seconds, ideal for monitoring areal structures like dams, landslides and open pit mines (displacement accuracy up to 0.1 mm). The MetaSensing FastGBSAR is the first ground based SAR instrument on the market able to produce two-dimensional deformation maps with this high acquisition rate. By that, deformation time series with a high temporal and spatial resolution can be generated, giving detailed information useful to determine the deformation mechanisms involved and eventually to predict an incoming failure. The system is fully portable and can be quickly installed on bedrock or a basement. The data acquisition and processing can be fully automated leading to a low effort in instrument operation and maintenance. Due to the short acquisition time of FastGBSAR, the coherence between two acquisitions is very high and the phase unwrapping is simplified enormously. This yields a high density of resolution cells with good quality and high reliability of the acquired deformations. The deformation maps can directly be used as input into an Early

  16. Ground and Space Radar Volume Matching and Comparison Software

    Science.gov (United States)

    Morris, Kenneth; Schwaller, Mathew

    2010-01-01

    This software enables easy comparison of ground- and space-based radar observations. The software was initially designed to compare ground radar reflectivity from operational, ground based Sand C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite s Precipitation Radar (PR) instrument. The software is also applicable to other ground-based and space-based radars. The ground and space radar volume matching and comparison software was developed in response to requirements defined by the Ground Validation System (GVS) of Goddard s Global Precipitation Mission (GPM) project. This software innovation is specifically concerned with simplifying the comparison of ground- and spacebased radar measurements for the purpose of GPM algorithm and data product validation. This software is unique in that it provides an operational environment to routinely create comparison products, and uses a direct geometric approach to derive common volumes of space- and ground-based radar data. In this approach, spatially coincident volumes are defined by the intersection of individual space-based Precipitation Radar rays with the each of the conical elevation sweeps of the ground radar. Thus, the resampled volume elements of the space and ground radar reflectivity can be directly compared to one another.

  17. Monitoring Strategies of Earth Dams by Ground-Based Radar Interferometry: How to Extract Useful Information for Seismic Risk Assessment.

    Science.gov (United States)

    Di Pasquale, Andrea; Nico, Giovanni; Pitullo, Alfredo; Prezioso, Giuseppina

    2018-01-16

    The aim of this paper is to describe how ground-based radar interferometry can provide displacement measurements of earth dam surfaces and of vibration frequencies of its main concrete infrastructures. In many cases, dams were built many decades ago and, at that time, were not equipped with in situ sensors embedded in the structure when they were built. Earth dams have scattering properties similar to landslides for which the Ground-Based Synthetic Aperture Radar (GBSAR) technique has been so far extensively applied to study ground displacements. In this work, SAR and Real Aperture Radar (RAR) configurations are used for the measurement of earth dam surface displacements and vibration frequencies of concrete structures, respectively. A methodology for the acquisition of SAR data and the rendering of results is described. The geometrical correction factor, needed to transform the Line-of-Sight (LoS) displacement measurements of GBSAR into an estimate of the horizontal displacement vector of the dam surface, is derived. Furthermore, a methodology for the acquisition of RAR data and the representation of displacement temporal profiles and vibration frequency spectra of dam concrete structures is presented. For this study a Ku-band ground-based radar, equipped with horn antennas having different radiation patterns, has been used. Four case studies, using different radar acquisition strategies specifically developed for the monitoring of earth dams, are examined. The results of this work show the information that a Ku-band ground-based radar can provide to structural engineers for a non-destructive seismic assessment of earth dams.

  18. Ground penetrating radar antenna measurements based on plane-wave expansions

    DEFF Research Database (Denmark)

    Lenler-Eriksen, Hans-Rudolph; Meincke, Peter

    2005-01-01

    The plane-wave transmitting spectrum of the system consisting of the ground penetrating radar (GPR) antenna and the air-soil interface is measured using a loop buried in the soil. The plane-wave spectrum is used to determine various parameters characterizing the radiation of the GPR antenna...

  19. Estimation of High-Frequency Earth-Space Radio Wave Signals via Ground-Based Polarimetric Radar Observations

    Science.gov (United States)

    Bolen, Steve; Chandrasekar, V.

    2002-01-01

    Expanding human presence in space, and enabling the commercialization of this frontier, is part of the strategic goals for NASA's Human Exploration and Development of Space (HEDS) enterprise. Future near-Earth and planetary missions will support the use of high-frequency Earth-space communication systems. Additionally, increased commercial demand on low-frequency Earth-space links in the S- and C-band spectra have led to increased interest in the use of higher frequencies in regions like Ku and Ka-band. Attenuation of high-frequency signals, due to a precipitating medium, can be quite severe and can cause considerable disruptions in a communications link that traverses such a medium. Previously, ground radar measurements were made along the Earth-space path and compared to satellite beacon data that was transmitted to a ground station. In this paper, quantitative estimation of the attenuation along the propagation path is made via inter-comparisons of radar data taken from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and ground-based polarimetric radar observations. Theoretical relationships between the expected specific attenuation (k) of spaceborne measurements with ground-based measurements of reflectivity (Zh) and differential propagation phase shift (Kdp) are developed for various hydrometeors that could be present along the propagation path, which are used to estimate the two-way path-integrated attenuation (PIA) on the PR return echo. Resolution volume matching and alignment of the radar systems is performed, and a direct comparison of PR return echo with ground radar attenuation estimates is made directly on a beam-by-beam basis. The technique is validated using data collected from the TExas and Florida UNderflights (TEFLUN-B) experiment and the TRMM large Biosphere-Atmosphere experiment in Amazonia (LBA) campaign. Attenuation estimation derived from this method can be used for strategiC planning of communication systems for

  20. Ground-Based Observations and Modeling of the Visibility and Radar Reflectivity in a Radiation Fog Layer

    NARCIS (Netherlands)

    Boers, R.; Baltink, K.H.; Hemink, H.J.; Bosveld, F.C.; Moerman, M.

    2013-01-01

    The development of a radiation fog layer at the Cabauw Experimental Site for Atmospheric Research(51.97°N, 4.93°E) on 23 March 2011 was observed with ground-based in situ and remote sensing observationsto investigate the relationship between visibility and radar reflectivity. The fog layer thickness

  1. Characteristics of Volcanic Stratospheric Aerosol Layer Observed by CALIOP and Ground Based Lidar at Equatorial Atmosphere Radar Site

    Science.gov (United States)

    Abo, Makoto; Shibata, Yasukuni; Nagasawa, Chikao

    2018-04-01

    We investigated the relation between major tropical volcanic eruptions in the equatorial region and the stratospheric aerosol data, which have been collected by the ground based lidar observations at at Equatorial Atmosphere Radar site between 2004 and 2015 and the CALIOP observations in low latitude between 2006 and 2015. We found characteristic dynamic behavior of volcanic stratospheric aerosol layers over equatorial region.

  2. Quantitative Estimation of Above Ground Crop Biomass using Ground-based, Airborne and Spaceborne Low Frequency Polarimetric Synthetic Aperture Radar

    Science.gov (United States)

    Koyama, C.; Watanabe, M.; Shimada, M.

    2016-12-01

    Estimation of crop biomass is one of the important challenges in environmental remote sensing related to agricultural as well as hydrological and meteorological applications. Usually passive optical data (photographs, spectral data) operating in the visible and near-infrared bands is used for such purposes. The virtue of optical remote sensing for yield estimation, however, is rather limited as the visible light can only provide information about the chemical characteristics of the canopy surface. Low frequency microwave signals with wavelength longer 20 cm have the potential to penetrate through the canopy and provide information about the whole vertical structure of vegetation from the top of the canopy down to the very soil surface. This phenomenon has been well known and exploited to detect targets under vegetation in the military radar application known as FOPEN (foliage penetration). With the availability of polarimetric interferometric SAR data the use PolInSAR techniques to retrieve vertical vegetation structures has become an attractive tool. However, PolInSAR is still highly experimental and suitable data is not yet widely available. In this study we focus on the use of operational dual-polarization L-band (1.27 GHz) SAR which is since the launch of Japan's Advanced Land Observing Satellite (ALOS, 2006-2011) available worldwide. Since 2014 ALOS-2 continues to deliver such kind of partial polarimetric data for the entire land surface. In addition to these spaceborne data sets we use airborne L-band SAR data acquired by the Japanese Pi-SAR-L2 as well as ultra-wideband (UWB) ground based SAR data operating in the frequency range from 1-4 GHz. By exploiting the complex dual-polarization [C2] Covariance matrix information, the scattering contributions from the canopy can be well separated from the ground reflections allowing for the establishment of semi-empirical relationships between measured radar reflectivity and the amount of fresh-weight above-ground

  3. Guidance Trades for Interceptors Not Constrained by Ground-Based Radar

    National Research Council Canada - National Science Library

    Deutsch, Owen

    2000-01-01

    .... New space-based sensor systems such as SBIRS-low are seen as an adjunct that can be used to achieve range extension by cueing of radars and in some concepts, kinematic range extension of interceptors...

  4. Measurement of Precipitation in the Alps Using Dual-Polarization C-Band Ground-Based Radars, the GPM Spaceborne Ku-Band Radar, and Rain Gauges

    Directory of Open Access Journals (Sweden)

    Marco Gabella

    2017-11-01

    Full Text Available The complex problem of quantitative precipitation estimation in the Alpine region is tackled from four different points of view: (1 the modern MeteoSwiss network of automatic telemetered rain gauges (GAUGE; (2 the recently upgraded MeteoSwiss dual-polarization Doppler, ground-based weather radar network (RADAR; (3 a real-time merging of GAUGE and RADAR, implemented at MeteoSwiss, in which a technique based on co-kriging with external drift (CombiPrecip is used; (4 spaceborne observations, acquired by the dual-wavelength precipitation radar on board the Global Precipitation Measuring (GPM core satellite. There are obviously large differences in these sampling modes, which we have tried to minimize by integrating synchronous observations taken during the first 2 years of the GPM mission. The data comprises 327 “wet” overpasses of Switzerland, taken after the launch of GPM in February 2014. By comparing the GPM radar estimates with the MeteoSwiss products, a similar performance was found in terms of bias. On average (whole country, all days and seasons, both solid and liquid phases, underestimation is as large as −3.0 (−3.4 dB with respect to RADAR (GAUGE. GPM is not suitable for assessing what product is the best in terms of average precipitation over the Alps. GPM can nevertheless be used to evaluate the dispersion of the error around the mean, which is a measure of the geographical distribution of the error inside the country. Using 221 rain-gauge sites, the result is clear both in terms of correlation and in terms of scatter (a robust, weighted measure of the dispersion of the multiplicative error around the mean. The best agreement was observed between GPM and CombiPrecip, and, next, between GPM and RADAR, whereas a larger disagreement was found between GPM and GAUGE. Hence, GPM confirms that, for precipitation mapping in the Alpine region, the best results are obtained by combining ground-based radar with rain-gauge measurements using

  5. Ground based interferometric radar initial look at Longview, Blue Springs, Tuttle Creek, and Milford Dams

    Science.gov (United States)

    Deng, Huazeng

    Measuring millimeter and smaller deformation has been demonstrated in the literature using RADAR. To address in part the limitations in current commercial satellite-based SAR datasets, a University of Missouri (MU) team worked with GAMMA Remote Sensing to develop a specialized (dual-frequency, polarimetric, and interferometric) ground-based real-aperture RADAR (GBIR) instrument. The GBIR device is portable with its tripod system and control electronics. It can be deployed to obtain data with high spatial resolution (i.e. on the order of 1 meter) and high temporal resolution (i.e. on the order 1 minute). The high temporal resolution is well suited for measurements of rapid deformation. From the same geodetic position, the GBIR may collect dual frequency data set using C-band and Ku-band. The overall goal of this project is to measure the deformation from various scenarios by applying the GBIR system. Initial efforts have been focusing on testing the system performance on different types of targets. This thesis details a number of my efforts on experimental and processing activities at the start of the MU GBIR imaging project. For improved close range capability, a wideband dual polarized antenna option was produced and tested. For GBIR calibration, several trihedral corner reflectors were designed and fabricated. In addition to experimental activities and site selection, I participated in advanced data processing activities. I processed GBIR data in several ways including single-look-complex (SLC) image generation, imagery registration, and interferometric processing. A number of initial-processed GBIR image products are presented from four dams: Longview, Blue Springs, Tuttle Creek, and Milford. Excellent imaging performance of the MU GBIR has been observed for various target types such as riprap, concrete, soil, rock, metal, and vegetation. Strong coherence of the test scene has been observed in the initial interferograms.

  6. Intercomparison of Vertical Structure of Storms Revealed by Ground-Based (NMQ and Spaceborne Radars (CloudSat-CPR and TRMM-PR

    Directory of Open Access Journals (Sweden)

    Veronica M. Fall

    2013-01-01

    Full Text Available Spaceborne radars provide great opportunities to investigate the vertical structure of clouds and precipitation. Two typical spaceborne radars for such a study are the W-band Cloud Profiling Radar (CPR and Ku-band Precipitation Radar (PR, which are onboard NASA’s CloudSat and TRMM satellites, respectively. Compared to S-band ground-based radars, they have distinct scattering characteristics for different hydrometeors in clouds and precipitation. The combination of spaceborne and ground-based radar observations can help in the identification of hydrometeors and improve the radar-based quantitative precipitation estimation (QPE. This study analyzes the vertical structure of the 18 January, 2009 storm using data from the CloudSat CPR, TRMM PR, and a NEXRAD-based National Mosaic and Multisensor QPE (NMQ system. Microphysics above, within, and below the melting layer are studied through an intercomparison of multifrequency measurements. Hydrometeors’ type and their radar scattering characteristics are analyzed. Additionally, the study of the vertical profile of reflectivity (VPR reveals the brightband properties in the cold-season precipitation and its effect on the radar-based QPE. In all, the joint analysis of spaceborne and ground-based radar data increases the understanding of the vertical structure of storm systems and provides a good insight into the microphysical modeling for weather forecasts.

  7. Toward a Framework for Systematic Error Modeling of NASA Spaceborne Radar with NOAA/NSSL Ground Radar-Based National Mosaic QPE

    Science.gov (United States)

    Kirstettier, Pierre-Emmanual; Honh, Y.; Gourley, J. J.; Chen, S.; Flamig, Z.; Zhang, J.; Howard, K.; Schwaller, M.; Petersen, W.; Amitai, E.

    2011-01-01

    Characterization of the error associated to satellite rainfall estimates is a necessary component of deterministic and probabilistic frameworks involving space-born passive and active microwave measurement") for applications ranging from water budget studies to forecasting natural hazards related to extreme rainfall events. We focus here on the error structure of NASA's Tropical Rainfall Measurement Mission (TRMM) Precipitation Radar (PR) quantitative precipitation estimation (QPE) at ground. The problem is addressed by comparison of PR QPEs with reference values derived from ground-based measurements using NOAA/NSSL ground radar-based National Mosaic and QPE system (NMQ/Q2). A preliminary investigation of this subject has been carried out at the PR estimation scale (instantaneous and 5 km) using a three-month data sample in the southern part of US. The primary contribution of this study is the presentation of the detailed steps required to derive trustworthy reference rainfall dataset from Q2 at the PR pixel resolution. It relics on a bias correction and a radar quality index, both of which provide a basis to filter out the less trustworthy Q2 values. Several aspects of PR errors arc revealed and quantified including sensitivity to the processing steps with the reference rainfall, comparisons of rainfall detectability and rainfall rate distributions, spatial representativeness of error, and separation of systematic biases and random errors. The methodology and framework developed herein applies more generally to rainfall rate estimates from other sensors onboard low-earth orbiting satellites such as microwave imagers and dual-wavelength radars such as with the Global Precipitation Measurement (GPM) mission.

  8. Multi-Feature Based Multiple Landmine Detection Using Ground Penetration Radar

    Directory of Open Access Journals (Sweden)

    S. Park

    2014-06-01

    Full Text Available This paper presents a novel method for detection of multiple landmines using a ground penetrating radar (GPR. Conventional algorithms mainly focus on detection of a single landmine, which cannot linearly extend to the multiple landmine case. The proposed algorithm is composed of four steps; estimation of the number of multiple objects buried in the ground, isolation of each object, feature extraction and detection of landmines. The number of objects in the GPR signal is estimated by using the energy projection method. Then signals for the objects are extracted by using the symmetry filtering method. Each signal is then processed for features, which are given as input to the support vector machine (SVM for landmine detection. Three landmines buried in various ground conditions are considered for the test of the proposed method. They demonstrate that the proposed method can successfully detect multiple landmines.

  9. Development of Deep Learning Based Data Fusion Approach for Accurate Rainfall Estimation Using Ground Radar and Satellite Precipitation Products

    Science.gov (United States)

    Chen, H.; Chandra, C. V.; Tan, H.; Cifelli, R.; Xie, P.

    2016-12-01

    Rainfall estimation based on onboard satellite measurements has been an important topic in satellite meteorology for decades. A number of precipitation products at multiple time and space scales have been developed based upon satellite observations. For example, NOAA Climate Prediction Center has developed a morphing technique (i.e., CMORPH) to produce global precipitation products by combining existing space based rainfall estimates. The CMORPH products are essentially derived based on geostationary satellite IR brightness temperature information and retrievals from passive microwave measurements (Joyce et al. 2004). Although the space-based precipitation products provide an excellent tool for regional and global hydrologic and climate studies as well as improved situational awareness for operational forecasts, its accuracy is limited due to the sampling limitations, particularly for extreme events such as very light and/or heavy rain. On the other hand, ground-based radar is more mature science for quantitative precipitation estimation (QPE), especially after the implementation of dual-polarization technique and further enhanced by urban scale radar networks. Therefore, ground radars are often critical for providing local scale rainfall estimation and a "heads-up" for operational forecasters to issue watches and warnings as well as validation of various space measurements and products. The CASA DFW QPE system, which is based on dual-polarization X-band CASA radars and a local S-band WSR-88DP radar, has demonstrated its excellent performance during several years of operation in a variety of precipitation regimes. The real-time CASA DFW QPE products are used extensively for localized hydrometeorological applications such as urban flash flood forecasting. In this paper, a neural network based data fusion mechanism is introduced to improve the satellite-based CMORPH precipitation product by taking into account the ground radar measurements. A deep learning system is

  10. A Semiautomated Multilayer Picking Algorithm for Ice-sheet Radar Echograms Applied to Ground-Based Near-Surface Data

    Science.gov (United States)

    Onana, Vincent De Paul; Koenig, Lora Suzanne; Ruth, Julia; Studinger, Michael; Harbeck, Jeremy P.

    2014-01-01

    Snow accumulation over an ice sheet is the sole mass input, making it a primary measurement for understanding the past, present, and future mass balance. Near-surface frequency-modulated continuous-wave (FMCW) radars image isochronous firn layers recording accumulation histories. The Semiautomated Multilayer Picking Algorithm (SAMPA) was designed and developed to trace annual accumulation layers in polar firn from both airborne and ground-based radars. The SAMPA algorithm is based on the Radon transform (RT) computed by blocks and angular orientations over a radar echogram. For each echogram's block, the RT maps firn segmented-layer features into peaks, which are picked using amplitude and width threshold parameters of peaks. A backward RT is then computed for each corresponding block, mapping the peaks back into picked segmented-layers. The segmented layers are then connected and smoothed to achieve a final layer pick across the echogram. Once input parameters are trained, SAMPA operates autonomously and can process hundreds of kilometers of radar data picking more than 40 layers. SAMPA final pick results and layer numbering still require a cursory manual adjustment to correct noncontinuous picks, which are likely not annual, and to correct for inconsistency in layer numbering. Despite the manual effort to train and check SAMPA results, it is an efficient tool for picking multiple accumulation layers in polar firn, reducing time over manual digitizing efforts. The trackability of good detected layers is greater than 90%.

  11. Monsoon Convective During the South China Sea Monsoon Experiment: Observations from Ground-Based Radar and the TRMM Satellite

    Science.gov (United States)

    Cifelli, Rob; Rickenbach, Tom; Halverson, Jeff; Keenan, Tom; Kucera, Paul; Atkinson, Lester; Fisher, Brad; Gerlach, John; Harris, Kathy; Kaufman, Cristina

    1999-01-01

    A main goal of the recent South China Sea Monsoon Experiment (SCSMEX) was to study convective processes associated with the onset of the Southeast Asian summer monsoon. The NASA TOGA C-band scanning radar was deployed on the Chinese research vessel Shi Yan #3 for two 20 day cruises, collecting dual-Doppler measurements in conjunction with the BMRC C-Pol dual-polarimetric radar on Dongsha Island. Soundings and surface meteorological data were also collected with an NCAR Integrated Sounding System (ISS). This experiment was the first major tropical field campaign following the launch of the Tropical Rainfall Measuring Mission (TRMM) satellite. These observations of tropical oceanic convection provided an opportunity to make comparisons between surface radar measurements and the Precipitation Radar (PR) aboard the TRMM satellite in an oceanic environment. Nearly continuous radar operations were conducted during two Intensive Observing Periods (IOPS) straddling the onset of the monsoon (5-25 May 1998 and 5-25 June 1998). Mesoscale lines of convection with widespread regions of both trailing and forward stratiform precipitation were observed following the onset of the active monsoon in the northern South China Sea region. The vertical structure of the convection during periods of strong westerly flow and relatively moist environmental conditions in the lower to mid-troposphere contrasted sharply with convection observed during periods of low level easterlies, weak shear, and relatively dry conditions in the mid to upper troposphere. Several examples of mesoscale convection will be shown from the ground (ship)-based and spaceborne radar data during times of TRMM satellite overpasses. Examples of pre-monsoon convection, characterized by isolated cumulonimbus and shallow, precipitating congestus clouds, will also be discussed.

  12. Comparison of Ground- and Space-based Radar Observations with Disdrometer Measurements During the PECAN Field Campaign

    Science.gov (United States)

    Torres, A. D.; Rasmussen, K. L.; Bodine, D. J.; Dougherty, E.

    2015-12-01

    Plains Elevated Convection At Night (PECAN) was a large field campaign that studied nocturnal mesoscale convective systems (MCSs), convective initiation, bores, and low-level jets across the central plains in the United States. MCSs are responsible for over half of the warm-season precipitation across the central U.S. plains. The rainfall from deep convection of these systems over land have been observed to be underestimated by satellite radar rainfall-retrieval algorithms by as much as 40 percent. These algorithms have a strong dependence on the generally unmeasured rain drop-size distribution (DSD). During the campaign, our group measured rainfall DSDs, precipitation fall velocities, and total precipitation in the convective and stratiform regions of MCSs using Ott Parsivel optical laser disdrometers. The disdrometers were co-located with mobile pod units that measured temperature, wind, and relative humidity for quality control purposes. Data from the operational NEXRAD radar in LaCrosse, Wisconsin and space-based radar measurements from a Global Precipitation Measurement satellite overpass on July 13, 2015 were used for the analysis. The focus of this study is to compare DSD measurements from the disdrometers to radars in an effort to reduce errors in existing rainfall-retrieval algorithms. The error analysis consists of substituting measured DSDs into existing quantitative precipitation estimation techniques (e.g. Z-R relationships and dual-polarization rain estimates) and comparing these estimates to ground measurements of total precipitation. The results from this study will improve climatological estimates of total precipitation in continental convection that are used in hydrological studies, climate models, and other applications.

  13. Identifying structural damage with ground penetrating radar

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2008-07-01

    Full Text Available Ground penetrating radar (GPR) and electrical resistance tomography (ERT) surveys were conducted in an urban environment in an attempt to identify the cause of severe structural damage to a historically significant residential property...

  14. Three-dimensional fusion of spaceborne and ground radar reflectivity data using a neural network-based approach

    Science.gov (United States)

    Kou, Leilei; Wang, Zhuihui; Xu, Fen

    2018-03-01

    The spaceborne precipitation radar onboard the Tropical Rainfall Measuring Mission satellite (TRMM PR) can provide good measurement of the vertical structure of reflectivity, while ground radar (GR) has a relatively high horizontal resolution and greater sensitivity. Fusion of TRMM PR and GR reflectivity data may maximize the advantages from both instruments. In this paper, TRMM PR and GR reflectivity data are fused using a neural network (NN)-based approach. The main steps included are: quality control of TRMM PR and GR reflectivity data; spatiotemporal matchup; GR calibration bias correction; conversion of TRMM PR data from Ku to S band; fusion of TRMM PR and GR reflectivity data with an NN method; interpolation of reflectivity data that are below PR's sensitivity; blind areas compensation with a distance weighting-based merging approach; combination of three types of data: data with the NN method, data below PR's sensitivity and data within compensated blind areas. During the NN fusion step, the TRMM PR data are taken as targets of the training NNs, and gridded GR data after horizontal downsampling at different heights are used as the input. The trained NNs are then used to obtain 3D high-resolution reflectivity from the original GR gridded data. After 3D fusion of the TRMM PR and GR reflectivity data, a more complete and finer-scale 3D radar reflectivity dataset incorporating characteristics from both the TRMM PR and GR observations can be obtained. The fused reflectivity data are evaluated based on a convective precipitation event through comparison with the high resolution TRMM PR and GR data with an interpolation algorithm.

  15. Forestry applications of ground-penetrating radar

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzo, H.; Perez-Gracia, V.; Novo, A.; Armesto, J.

    2010-07-01

    Ground-penetrating radar (GPR) is a geophysical and close-range remote sensing technique based on the use of radar pulses to obtain cross-section images of underground features. This method is characterized by the transmission of an electromagnetic short length pulse (1-2 ns), presenting a centre frequency ranging from 10 MHz to 2.5 GHz. The principles of GPR operation are based on the ability of low frequency radar waves to penetrate into a non-conductive medium, usually subsoil, but also walls, concrete or wood. Those waves are detected after suffering a reflection in electromagnetic discontinuities of the propagation medium. Therefore, this is a suitable method to study changes in those physical properties, and also to characterize different mediums and the reflective targets providing information about their physical properties. The aim of this work is to describe and demonstrate different applications of GPR in forestry, showing the obtained results together with their interpretation. Firstly, in this paper, it is illustrated how GPR is able to map shallow bedrock, subsoil stratigraphy and also to estimate shallow water table depth. Secondly, different tree trunks as well as dry timber are analyzed, evaluating the different radar data obtained in each particular case, and observing differences in their electromagnetic properties related to the GPR response. Finally, several measurements were taken in order to analyze the use of GPR to detect tree root systems using polarimetric techniques, being possible to detect medium and big size roots, together with groups of small roots. (Author) 39 refs.

  16. Performance evaluation of lunar penetrating radar onboard the rover of CE-3 probe based on results from ground experiments

    Science.gov (United States)

    Zhang, Hong-Bo; Zheng, Lei; Su, Yan; Fang, Guang-You; Zhou, Bin; Feng, Jian-Qing; Xing, Shu-Guo; Dai, Shun; Li, Jun-Duo; Ji, Yi-Cai; Gao, Yun-Ze; Xiao, Yuan; Li, Chun-Lai

    2014-12-01

    Lunar Penetrating Radar (LPR) onboard the rover that is part of the Chang'e-3 (CE-3) mission was firstly utilized to obtain in situ measurements about geological structure on the lunar surface and the thickness of the lunar regolith, which are key elements for studying the evolutional history of lunar crust. Because penetration depth and resolution of LPR are related to the scientific objectives of this mission, a series of ground-based experiments using LPR was carried out, and results of the experimental data were obtained in a glacial area located in the northwest region of China. The results show that the penetration depth of the first channel antenna used for LPR is over 79 m with a resolution of 2.8 m, and that for the second channel antenna is over 50.8 m with a resolution of 17.1 cm.

  17. Performance evaluation of lunar penetrating radar onboard the rover of CE-3 probe based on results from ground experiments

    International Nuclear Information System (INIS)

    Zhang Hong-Bo; Zheng Lei; Su Yan; Feng Jian-Qing; Xing Shu-Guo; Dai Shun; Li Jun-Duo; Xiao Yuan; Li Chun-Lai; Fang Guang-You; Zhou Bin; Ji Yi-Cai; Gao Yun-Ze

    2014-01-01

    Lunar Penetrating Radar (LPR) onboard the rover that is part of the Chang'e-3 (CE-3) mission was firstly utilized to obtain in situ measurements about geological structure on the lunar surface and the thickness of the lunar regolith, which are key elements for studying the evolutional history of lunar crust. Because penetration depth and resolution of LPR are related to the scientific objectives of this mission, a series of ground-based experiments using LPR was carried out, and results of the experimental data were obtained in a glacial area located in the northwest region of China. The results show that the penetration depth of the first channel antenna used for LPR is over 79 m with a resolution of 2.8 m, and that for the second channel antenna is over 50.8 m with a resolution of 17.1 cm

  18. The influence on the interferometry due to the instability of ground-based synthetic aperture radar work platform

    Science.gov (United States)

    Tao, Gang; Wei, Guohua; Wang, Xu; Kong, Ming

    2018-03-01

    There has been increased interest over several decades for applying ground-based synthetic aperture radar (GB-SAR) for monitoring terrain displacement. GB-SAR can achieve multitemporal surface deformation maps of the entire terrain with high spatial resolution and submilimetric accuracy due to the ability of continuous monitoring a certain area day and night regardless of the weather condition. The accuracy of the interferometric measurement result is very important. In this paper, the basic principle of InSAR is expounded, the influence of the platform's instability on the interferometric measurement results are analyzed. The error sources of deformation detection estimation are analyzed using precise geometry of imaging model. Finally, simulation results demonstrates the validity of our analysis.

  19. RESEARCH ON VISUALIZATION OF GROUND LASER RADAR DATA BASED ON OSG

    Directory of Open Access Journals (Sweden)

    H. Huang

    2018-04-01

    Full Text Available Three-dimensional (3D laser scanning is a new advanced technology integrating light, machine, electricity, and computer technologies. It can conduct 3D scanning to the whole shape and form of space objects with high precision. With this technology, you can directly collect the point cloud data of a ground object and create the structure of it for rendering. People use excellent 3D rendering engine to optimize and display the 3D model in order to meet the higher requirements of real time realism rendering and the complexity of the scene. OpenSceneGraph (OSG is an open source 3D graphics engine. Compared with the current mainstream 3D rendering engine, OSG is practical, economical, and easy to expand. Therefore, OSG is widely used in the fields of virtual simulation, virtual reality, science and engineering visualization. In this paper, a dynamic and interactive ground LiDAR data visualization platform is constructed based on the OSG and the cross-platform C++ application development framework Qt. In view of the point cloud data of .txt format and the triangulation network data file of .obj format, the functions of 3D laser point cloud and triangulation network data display are realized. It is proved by experiments that the platform is of strong practical value as it is easy to operate and provides good interaction.

  20. Research on Visualization of Ground Laser Radar Data Based on Osg

    Science.gov (United States)

    Huang, H.; Hu, C.; Zhang, F.; Xue, H.

    2018-04-01

    Three-dimensional (3D) laser scanning is a new advanced technology integrating light, machine, electricity, and computer technologies. It can conduct 3D scanning to the whole shape and form of space objects with high precision. With this technology, you can directly collect the point cloud data of a ground object and create the structure of it for rendering. People use excellent 3D rendering engine to optimize and display the 3D model in order to meet the higher requirements of real time realism rendering and the complexity of the scene. OpenSceneGraph (OSG) is an open source 3D graphics engine. Compared with the current mainstream 3D rendering engine, OSG is practical, economical, and easy to expand. Therefore, OSG is widely used in the fields of virtual simulation, virtual reality, science and engineering visualization. In this paper, a dynamic and interactive ground LiDAR data visualization platform is constructed based on the OSG and the cross-platform C++ application development framework Qt. In view of the point cloud data of .txt format and the triangulation network data file of .obj format, the functions of 3D laser point cloud and triangulation network data display are realized. It is proved by experiments that the platform is of strong practical value as it is easy to operate and provides good interaction.

  1. A ground-base Radar network to access the 3D structure of MLT winds

    Science.gov (United States)

    Stober, G.; Chau, J. L.; Wilhelm, S.; Jacobi, C.

    2016-12-01

    The mesosphere/lower thermosphere (MLT) is a highly variable atmospheric region driven by wave dynamics at various scales including planetary waves, tides and gravity waves. Some of these propagate through the MLT into the thermosphere/ionosphere carrying energy and momentum from the middle atmosphere into the upper atmosphere. To improve our understanding of the wave energetics and momentum transfer during their dissipation it is essential to characterize their space time properties. During the last two years we developed a new experimental approach to access the horizontal structure of wind fields at the MLT using a meteor radar network in Germany, which we called MMARIA - Multi-static Multi-frequency Agile Radar for Investigation of the Atmosphere. The network combines classical backscatter meteor radars and passive forward scatter radio links. We present our preliminary results using up to 7 different active and passive radio links to obtain horizontally resolved wind fields applying a statistical inverse method. The wind fields are retrieved with 15-30 minutes temporal resolution on a grid with 30x30 km horizontal spacing. Depending on the number of observed meteors, we are able to apply the wind field inversion at heights between 84-94 km. The horizontally resolved wind fields provide insights of the typical horizontal gravity wave length and the energy cascade from large scales to small scales. We present first power spectra indicating the transition from the synoptic wave scale to the gravity wave scale.

  2. Civil engineering applications of ground penetrating radar

    CERN Document Server

    Pajewski, Lara

    2015-01-01

    This book, based on Transport and Urban Development COST Action TU1208, presents the most advanced applications of ground penetrating radar (GPR) in a civil engineering context, with documentation of instrumentation, methods, and results. It explains clearly how GPR can be employed for the surveying of critical transport infrastructure, such as roads, pavements, bridges, and tunnels, and for the sensing and mapping of underground utilities and voids. Detailed attention is also devoted to use of GPR in the inspection of geological structures and of construction materials and structures, including reinforced concrete, steel reinforcing bars, and pre/post-tensioned stressing ducts. Advanced methods for solution of electromagnetic scattering problems and new data processing techniques are also presented. Readers will come to appreciate that GPR is a safe, advanced, nondestructive, and noninvasive imaging technique that can be effectively used for the inspection of composite structures and the performance of diagn...

  3. Quantification of Reflection Patterns in Ground-Penetrating Radar Data

    Science.gov (United States)

    Moysey, S.; Knight, R. J.; Jol, H. M.; Allen-King, R. M.; Gaylord, D. R.

    2005-12-01

    Radar facies analysis provides a way of interpreting the large-scale structure of the subsurface from ground-penetrating radar (GPR) data. Radar facies are often distinguished from each other by the presence of patterns, such as flat-lying, dipping, or chaotic reflections, in different regions of a radar image. When these patterns can be associated with radar facies in a repeated and predictable manner we refer to them as `radar textures'. While it is often possible to qualitatively differentiate between radar textures visually, pattern recognition tools, like neural networks, require a quantitative measure to discriminate between them. We investigate whether currently available tools, such as instantaneous attributes or metrics adapted from standard texture analysis techniques, can be used to improve the classification of radar facies. To this end, we use a neural network to perform cross-validation tests that assess the efficacy of different textural measures for classifying radar facies in GPR data collected from the William River delta, Saskatchewan, Canada. We found that the highest classification accuracies (>93%) were obtained for measures of texture that preserve information about the spatial arrangement of reflections in the radar image, e.g., spatial covariance. Lower accuracy (87%) was obtained for classifications based directly on windows of amplitude data extracted from the radar image. Measures that did not account for the spatial arrangement of reflections in the image, e.g., instantaneous attributes and amplitude variance, yielded classification accuracies of less than 65%. Optimal classifications were obtained for textural measures that extracted sufficient information from the radar data to discriminate between radar facies but were insensitive to other facies specific characteristics. For example, the rotationally invariant Fourier-Mellin transform delivered better classification results than the spatial covariance because dip angle of the

  4. Tree root mapping with ground penetrating radar

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2009-09-01

    Full Text Available In this paper, the application of ground penetrating radar (GPR) for the mapping of near surface tree roots is demonstrated. GPR enables tree roots to be mapped in a non-destructive and cost-effective manner and is therefore a useful prospecting...

  5. Evaluating Microphysics in Cloud-Resolving Models using TRMM and Ground-based Precipitation Radar Observations

    Science.gov (United States)

    Krueger, S. K.; Zulauf, M. A.; Li, Y.; Zipser, E. J.

    2005-05-01

    Global satellite datasets such as those produced by ISCCP, ERBE, and CERES provide strong observational constraints on cloud radiative properties. Such observations have been widely used for model evaluation, tuning, and improvement. Cloud radiative properties depend primarily on small, non-precipitating cloud droplets and ice crystals, yet the dynamical, microphysical and radiative processes which produce these small particles often involve large, precipitating hydrometeors. There now exists a global dataset of tropical cloud system precipitation feature (PF) properties, collected by TRMM and produced by Steve Nesbitt, that provides additional observational constraints on cloud system properties. We are using the TRMM PF dataset to evaluate the precipitation microphysics of two simulations of deep, precipitating, convective cloud systems: one is a 29-day summertime, continental case (ARM Summer 1997 SCM IOP, at the Southern Great Plains site); the second is a tropical maritime case: the Kwajalein MCS of 11-12 August 1999 (part of a 52-day simulation). Both simulations employed the same bulk, three-ice category microphysical parameterization (Krueger et al. 1995). The ARM simulation was executed using the UCLA/Utah 2D CRM, while the KWAJEX simulation was produced using the 3D CSU CRM (SAM). The KWAJEX simulation described above is compared with both the actual radar data and the TRMM statistics. For the Kwajalein MCS of 11 to 12 August 1999, there are research radar data available for the lifetime of the system. This particular MCS was large in size and rained heavily, but it was weak to average in measures of convective intensity, against the 5-year TRMM sample of 108. For the Kwajalein MCS simulation, the 20 dBZ contour is at 15.7 km and the 40 dBZ contour at 14.5 km! Of all 108 MCSs observed by TRMM, the highest value for the 40 dBZ contour is 8 km. Clearly, the high reflectivity cores are off scale compared with observed cloud systems in this area. A similar

  6. Cross-validation Methodology between Ground and GPM Satellite-based Radar Rainfall Product over Dallas-Fort Worth (DFW) Metroplex

    Science.gov (United States)

    Chen, H.; Chandrasekar, V.; Biswas, S.

    2015-12-01

    Over the past two decades, a large number of rainfall products have been developed based on satellite, radar, and/or rain gauge observations. However, to produce optimal rainfall estimation for a given region is still challenging due to the space time variability of rainfall at many scales and the spatial and temporal sampling difference of different rainfall instruments. In order to produce high-resolution rainfall products for urban flash flood applications and improve the weather sensing capability in urban environment, the center for Collaborative Adaptive Sensing of the Atmosphere (CASA), in collaboration with National Weather Service (NWS) and North Central Texas Council of Governments (NCTCOG), has developed an urban radar remote sensing network in DFW Metroplex. DFW is the largest inland metropolitan area in the U.S., that experiences a wide range of natural weather hazards such as flash flood and hailstorms. The DFW urban remote sensing network, centered by the deployment of eight dual-polarization X-band radars and a NWS WSR-88DP radar, is expected to provide impacts-based warning and forecasts for benefit of the public safety and economy. High-resolution quantitative precipitation estimation (QPE) is one of the major goals of the development of this urban test bed. In addition to ground radar-based rainfall estimation, satellite-based rainfall products for this area are also of interest for this study. Typical example is the rainfall rate product produced by the Dual-frequency Precipitation Radar (DPR) onboard Global Precipitation Measurement (GPM) Core Observatory satellite. Therefore, cross-comparison between ground and space-based rainfall estimation is critical to building an optimal regional rainfall system, which can take advantages of the sampling differences of different sensors. This paper presents the real-time high-resolution QPE system developed for DFW urban radar network, which is based upon the combination of S-band WSR-88DP and X

  7. Parameterizing road construction in route-based road weather models: can ground-penetrating radar provide any answers?

    International Nuclear Information System (INIS)

    Hammond, D S; Chapman, L; Thornes, J E

    2011-01-01

    A ground-penetrating radar (GPR) survey of a 32 km mixed urban and rural study route is undertaken to assess the usefulness of GPR as a tool for parameterizing road construction in a route-based road weather forecast model. It is shown that GPR can easily identify even the smallest of bridges along the route, which previous thermal mapping surveys have identified as thermal singularities with implications for winter road maintenance. Using individual GPR traces measured at each forecast point along the route, an inflexion point detection algorithm attempts to identify the depth of the uppermost subsurface layers at each forecast point for use in a road weather model instead of existing ordinal road-type classifications. This approach has the potential to allow high resolution modelling of road construction and bridge decks on a scale previously not possible within a road weather model, but initial results reveal that significant future research will be required to unlock the full potential that this technology can bring to the road weather industry. (technical design note)

  8. Big data managing in a landslide early warning system: experience from a ground-based interferometric radar application

    Directory of Open Access Journals (Sweden)

    E. Intrieri

    2017-10-01

    Full Text Available A big challenge in terms or landslide risk mitigation is represented by increasing the resiliency of society exposed to the risk. Among the possible strategies with which to reach this goal, there is the implementation of early warning systems. This paper describes a procedure to improve early warning activities in areas affected by high landslide risk, such as those classified as critical infrastructures for their central role in society. This research is part of the project LEWIS (Landslides Early Warning Integrated System: An Integrated System for Landslide Monitoring, Early Warning and Risk Mitigation along Lifelines. LEWIS is composed of a susceptibility assessment methodology providing information for single points and areal monitoring systems, a data transmission network and a data collecting and processing center (DCPC, where readings from all monitoring systems and mathematical models converge and which sets the basis for warning and intervention activities. The aim of this paper is to show how logistic issues linked to advanced monitoring techniques, such as big data transfer and storing, can be dealt with compatibly with an early warning system. Therefore, we focus on the interaction between an areal monitoring tool (a ground-based interferometric radar and the DCPC. By converting complex data into ASCII strings and through appropriate data cropping and average, and by implementing an algorithm for line-of-sight correction, we managed to reduce the data daily output without compromising the capability for performing.

  9. Big data managing in a landslide early warning system: experience from a ground-based interferometric radar application

    Science.gov (United States)

    Intrieri, Emanuele; Bardi, Federica; Fanti, Riccardo; Gigli, Giovanni; Fidolini, Francesco; Casagli, Nicola; Costanzo, Sandra; Raffo, Antonio; Di Massa, Giuseppe; Capparelli, Giovanna; Versace, Pasquale

    2017-10-01

    A big challenge in terms or landslide risk mitigation is represented by increasing the resiliency of society exposed to the risk. Among the possible strategies with which to reach this goal, there is the implementation of early warning systems. This paper describes a procedure to improve early warning activities in areas affected by high landslide risk, such as those classified as critical infrastructures for their central role in society. This research is part of the project LEWIS (Landslides Early Warning Integrated System): An Integrated System for Landslide Monitoring, Early Warning and Risk Mitigation along Lifelines. LEWIS is composed of a susceptibility assessment methodology providing information for single points and areal monitoring systems, a data transmission network and a data collecting and processing center (DCPC), where readings from all monitoring systems and mathematical models converge and which sets the basis for warning and intervention activities. The aim of this paper is to show how logistic issues linked to advanced monitoring techniques, such as big data transfer and storing, can be dealt with compatibly with an early warning system. Therefore, we focus on the interaction between an areal monitoring tool (a ground-based interferometric radar) and the DCPC. By converting complex data into ASCII strings and through appropriate data cropping and average, and by implementing an algorithm for line-of-sight correction, we managed to reduce the data daily output without compromising the capability for performing.

  10. Ground Penetrating Radar Imaging of Buried Metallic Objects

    DEFF Research Database (Denmark)

    Polat, A. Burak; Meincke, Peter

    2001-01-01

    During the past decade there has been considerable research on ground penetrating radar (GPR) tomography for detecting objects such as pipes, cables, mines and barrels buried under the surface of the Earth. While the earlier researches were all based on the assumption of a homogeneous background...

  11. Ground Penetrating Radar Technologies in Ukraine

    Science.gov (United States)

    Pochanin, Gennadiy P.; Masalov, Sergey A.

    2014-05-01

    Transient electromagnetic fields are of great interest in Ukraine. The following topics are studied by research teams, with high-level achievements all over the world: (i) Ultra-Wide Band/Short-pulse radar techniques (IRE and LLC "Transient Technologies", for more information please visit http://applied.ire.kharkov.ua/radar%20systems_their%20components%20and%20relevant%20technologies_e.html and http://viy.ua); (ii) Ground Penetrating Radar (GPR) with stepped frequency sounding signals (IRE); (iii) Continuous-Wave (CW) radar with phase-shift keying signals (IRE); and (iv) Radio-wave interference investigation (Scientific and Technical Centre of The Subsurface Investigation, http://geophysics.ua). GPR applications are mainly in search works, for example GPR is often used to search for treasures. It is also used to identify leaks and diffusion of petroleum in soil, in storage areas, as well as for fault location of pipelines. Furthermore, GPR is used for the localization of underground utilities and for diagnostics of the technical state of hydro dams. Deeper GPR probing was performed to identify landslides in Crimea. Rescue radar with CW signal was designed in IRE to search for living people trapped under the rubble of collapsed buildings. The fourth version of this radar has been recently created, showing higher stability and noise immunity. Radio-wave interference investigation allows studying the soil down to tens of meters. It is possible to identify areas with increased conductivity (moisture) of the soil. LLC "Transient Technologies" is currently working with Shevchenko Kyiv University on a cooperation program in which the construction of a test site is one of the planned tasks. In the framework of this program, a GPR with a 300 MHz antenna was handed to the geological Faculty of the University. Employees of "Transient Technologies" held introductory lectures with a practical demonstration for students majoring in geophysics. The authors participated to GPR

  12. Mapping plasma structures in the high-latitude ionosphere using beacon satellite, incoherent scatter radar and ground-based magnetometer observations

    Directory of Open Access Journals (Sweden)

    T. Neubert

    2002-06-01

    Full Text Available In the autumn of the year 2000, four radio receivers capable of tracking various beacon satellites were set up along the southwestern coast of Greenland. They are used to reconstruct images of the ionospheric plasma density distribution via the tomographic method. In order to test and validate tomographic imaging under the highly variable conditions often prevailing in the high-latitude ionosphere, a time interval was selected when the Sondrestrom incoherent scatter radar conducted measurements of the ionospheric plasma density while the radio receivers tracked a number of beacon satellites. A comparison between two-dimensional images of the plasma density distribution obtained from the radar and the satellite receivers revealed generally good agreement between radar measurements and tomographic images. Observed discrepancies can be attributed to F region plasma patches moving through the field of view with a speed of several hundred meters per second, thereby smearing out the tomographic image. A notable mismatch occurred around local magnetic midnight when a magnetospheric substorm breakup occurred in the vicinity of southwest Greenland (identified from ground-based magnetometer observations. The breakup was associated with a sudden intensification of the westward auroral electrojet which was centered at about 69 and extended up to some 73 corrected geomagnetic latitude. Ground-based magnetometer data may thus have the potential of indicating when the tomographic method is at risk and may fail. We finally outline the application of tomographic imaging, when combined with magnetic field data, to estimate ionospheric Joule heating rates.

  13. Miniature Ground Penetrating Radar, CRUX GPR

    Science.gov (United States)

    Kim, Soon Sam; Carnes, Steven R.; Haldemann, Albert F.; Ulmer, Christopher T.; Ng, Eddie; Arcone, Steven A.

    2006-01-01

    Under NASA instrument development programs (PIDDP 2000-2002, MIPD 2003-2005, ESR and T, 2005) we have been developing miniature ground penetrating radars (GPR) for use in mapping subsurface stratigraphy from planetary rovers for Mars and lunar applications. The Mars GPR is for deeper penetration (up to 50 m depth) into the Martian subsurface at moderate resolution (0.5 m) for a geological characterization. As a part of the CRUX (Construction and Resource Utilization Explorer) instrument suite, the CRUX GPR is optimized for a lunar prospecting application. It will have shallower penetration (5 m depth) with higher resolution (10 cm) for construction operations including ISRU (in-situ resource utilization).

  14. A compressive sensing-based computational method for the inversion of wide-band ground penetrating radar data

    Science.gov (United States)

    Gelmini, A.; Gottardi, G.; Moriyama, T.

    2017-10-01

    This work presents an innovative computational approach for the inversion of wideband ground penetrating radar (GPR) data. The retrieval of the dielectric characteristics of sparse scatterers buried in a lossy soil is performed by combining a multi-task Bayesian compressive sensing (MT-BCS) solver and a frequency hopping (FH) strategy. The developed methodology is able to benefit from the regularization capabilities of the MT-BCS as well as to exploit the multi-chromatic informative content of GPR measurements. A set of numerical results is reported in order to assess the effectiveness of the proposed GPR inverse scattering technique, as well as to compare it to a simpler single-task implementation.

  15. Comparison of cloud top heights derived from FY-2 meteorological satellites with heights derived from ground-based millimeter wavelength cloud radar

    Science.gov (United States)

    Wang, Zhe; Wang, Zhenhui; Cao, Xiaozhong; Tao, Fa

    2018-01-01

    Clouds are currently observed by both ground-based and satellite remote sensing techniques. Each technique has its own strengths and weaknesses depending on the observation method, instrument performance and the methods used for retrieval. It is important to study synergistic cloud measurements to improve the reliability of the observations and to verify the different techniques. The FY-2 geostationary orbiting meteorological satellites continuously observe the sky over China. Their cloud top temperature product can be processed to retrieve the cloud top height (CTH). The ground-based millimeter wavelength cloud radar can acquire information about the vertical structure of clouds-such as the cloud base height (CBH), CTH and the cloud thickness-and can continuously monitor changes in the vertical profiles of clouds. The CTHs were retrieved using both cloud top temperature data from the FY-2 satellites and the cloud radar reflectivity data for the same time period (June 2015 to May 2016) and the resulting datasets were compared in order to evaluate the accuracy of CTH retrievals using FY-2 satellites. The results show that the concordance rate of cloud detection between the two datasets was 78.1%. Higher consistencies were obtained for thicker clouds with larger echo intensity and for more continuous clouds. The average difference in the CTH between the two techniques was 1.46 km. The difference in CTH between low- and mid-level clouds was less than that for high-level clouds. An attenuation threshold of the cloud radar for rainfall was 0.2 mm/min; a rainfall intensity below this threshold had no effect on the CTH. The satellite CTH can be used to compensate for the attenuation error in the cloud radar data.

  16. Evaluating precipitation in a regional climate model using ground-based radar measurements in Dronning Maud Land, East Antarctica

    Science.gov (United States)

    Gorodetskaya, Irina; Maahn, Maximilan; Gallée, Hubert; Souverijns, Niels; Gossart, Alexandra; Kneifel, Stefan; Crewell, Susanne; Van Lipzig, Nicole

    2017-04-01

    Occasional very intense snowfall events over Dronning Maud Land (DML) region in East Antarctica, contributed significantly to the entire Antarctic ice sheet surface mass balance (SMB) during the last years. The meteorological-cloud-precipitation observatory running at the Princess Elisabeth station (PE) in the DML escarpment zone since 2009 (HYDRANT/AEROCLOUD projects), provides unique opportunity to estimate contribution of precipitation to the local snow accumulation and new data for evaluating precipitation in climate models. Our previous work using PE measurements showed that occasional intense precipitation events determine the total local yearly SMB and account for its large interannual variability. Here we use radar measurements to evaluate precipitation in a regional climate model with a special focus on intense precipitation events together with the large-scale atmospheric dynamics responsible for these events. The coupled snow-atmosphere regional climate model MAR (Modèle Atmosphérique Régional) is used to simulate climate and SMB in DML at 5-km horizontal resolution during 2012 using initial and boundary conditions from the European Centre for Medium-range Weather Forecasts (ECMWF) Interim re-analysis atmospheric and oceanic fields. Two evaluation approaches are used: observations-to-model and model-to-observations. In the first approach, snowfall rate (S) is derived from the MRR (vertically profiling 24-GHz precipitation radar) effective reflectivity factor (Ze) at 400 m agl using various Ze-S relationships for dry snow. The uncertainty in Ze-S relationships is constrained using snow particle size distribution from Snow Video Imager - Precipitation Imaging Package (SVI/PIP) and information about particle shapes. For the second approach we apply the Passive and Active Microwave radiative TRAnsfer model (PAMTRA), which allows direct comparison of the radar-measured and climate model-based vertical profiles of the radar Ze and Doppler velocity. In MAR

  17. Geological disaster survey based on Curvelet transform with borehole Ground Penetrating Radar in Tonglushan old mine site.

    Science.gov (United States)

    Tang, Xinjian; Sun, Tao; Tang, Zhijie; Zhou, Zenghui; Wei, Baoming

    2011-06-01

    Tonglushan old mine site located in Huangshi City, China, is very famous in the world. However, some of the ruins had suffered from geological disasters such as local deformation, surface cracking, in recent years. Structural abnormalities of rock-mass in deep underground were surveyed with borehole ground penetrating radar (GPR) to find out whether there were any mined galleries or mined-out areas below the ruins. With both the multiresolution analysis and sub-band directional of Curvelet transform, the feature information of targets' GPR signals were studied on Curvelet transform domain. Heterogeneity of geotechnical media and clutter jamming of complicated background of GPR signals could be conquered well, and the singularity characteristic information of typical rock mass signals could be extracted. Random noise had be removed by thresholding combined with Curvelet and the statistical characteristics of wanted signals and the noise, then direct wave suppression and the spatial distribution feature extraction could obtain a better result by making use of Curvelet transform directional. GprMax numerical modeling and analyzing of the sample data have verified the feasibility and effectiveness of our method. It is important and applicable for the analyzing of the geological structure and the disaster development about the Tonglushan old mine site. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  18. High performance ground penetrating radar survey of TA-49/Area 2. Final report

    International Nuclear Information System (INIS)

    Hoeberling, R.F.; Rangel, M.J. III

    1994-09-01

    The results of high performance ground penetrating radar study of Area 2 at Technical Area 49 are presented. The survey was commissioned as part of Los Alamos Laboratory's continuing Environmental Remediation program and was completed and analyzed before borehole studies in Area 2 were started. Based upon the ground penetrating radar results, the location of one of the planned boreholes was moved to assure the drilling area was as safe as possible. While earlier attempts to use commercial radar devices at this facility had not been successful, the radar and digital processing system developed at Los Alamos were able to significantly improve the buried physical detail of the site

  19. Investigating hydrocarbon contamination using ground penetrating radar

    International Nuclear Information System (INIS)

    Roest, P.B. van der; Brasser, D.J.S.; Wagebaert, A.P.J.; Stam, P.H.

    1996-01-01

    The increasing costs of remediating contaminated sites has stimulated research for cost reducing techniques in soil investigation and clean-up techniques. Under the traditional approach soil borings and groundwater wells are used to investigate contaminated soil. These are useful tools to determine the amount and characteristics of the contamination, but they are inefficient and costly in providing information on the location and extent of contamination as they only give information on one point. This often leads to uncertainty in estimating clean-up costs or, even worse, to unsuccessful clean-ups. MAP Environmental Research has developed a technology using Ground Penetrating Radar (GPR) in combination with in-house developed software to locate and define the extent of hydrocarbon contamination. With this technology, the quality of site investigation is increased while costs are reduced. Since 1994 MAP has been improving its technology and has applied it to over 100 projects, which all have been checked afterwards by conventional drilling. This paper gives some general characteristics of the method and presents a case study. The emphasis of this paper lies on the practical application of GPR to hydrocarbon contamination detection

  20. Joint synthetic aperture radar plus ground moving target indicator from single-channel radar using compressive sensing

    Science.gov (United States)

    Thompson, Douglas; Hallquist, Aaron; Anderson, Hyrum

    2017-10-17

    The various embodiments presented herein relate to utilizing an operational single-channel radar to collect and process synthetic aperture radar (SAR) and ground moving target indicator (GMTI) imagery from a same set of radar returns. In an embodiment, data is collected by randomly staggering a slow-time pulse repetition interval (PRI) over a SAR aperture such that a number of transmitted pulses in the SAR aperture is preserved with respect to standard SAR, but many of the pulses are spaced very closely enabling movers (e.g., targets) to be resolved, wherein a relative velocity of the movers places them outside of the SAR ground patch. The various embodiments of image reconstruction can be based on compressed sensing inversion from undersampled data, which can be solved efficiently using such techniques as Bregman iteration. The various embodiments enable high-quality SAR reconstruction, and high-quality GMTI reconstruction from the same set of radar returns.

  1. Ground penetrating radar evaluation of new pavement density.

    Science.gov (United States)

    2015-02-01

    The objective of this project was to map pavement surface density variations using dielectric : measurements from ground penetrating radar (GPR). The work was carried out as part of an : Asphalt Intelligent Compaction demonstration project on SR 539 ...

  2. Advanced Signal Analysis for Forensic Applications of Ground Penetrating Radar

    Energy Technology Data Exchange (ETDEWEB)

    Steven Koppenjan; Matthew Streeton; Hua Lee; Michael Lee; Sashi Ono

    2004-06-01

    Ground penetrating radar (GPR) systems have traditionally been used to image subsurface objects. The main focus of this paper is to evaluate an advanced signal analysis technique. Instead of compiling spatial data for the analysis, this technique conducts object recognition procedures based on spectral statistics. The identification feature of an object type is formed from the training vectors by a singular-value decomposition procedure. To illustrate its capability, this procedure is applied to experimental data and compared to the performance of the neural-network approach.

  3. Electromagnetic wave scattering by aerial and ground radar objects

    CERN Document Server

    Sukharevsky, Oleg I

    2014-01-01

    Electromagnetic Wave Scattering by Aerial and Ground Radar Objects presents the theory, original calculation methods, and computational results of the scattering characteristics of different aerial and ground radar objects. This must-have book provides essential background for computing electromagnetic wave scattering in the presence of different kinds of irregularities, as well as Summarizes fundamental electromagnetic statements such as the Lorentz reciprocity theorem and the image principleContains integral field representations enabling the study of scattering from various layered structur

  4. Use of ground-penetrating radar techniques in archaeological investigations

    Science.gov (United States)

    Doolittle, James A.; Miller, W. Frank

    1991-01-01

    Ground-penetrating radar (GPR) techniques are increasingly being used to aid reconnaissance and pre-excavation surveys at many archaeological sites. As a 'remote sensing' tool, GPR provides a high resolution graphic profile of the subsurface. Radar profiles are used to detect, identify, and locate buried artifacts. Ground-penetrating radar provides a rapid, cost effective, and nondestructive method for identification and location analyses. The GPR can be used to facilitate excavation strategies, provide greater areal coverage per unit time and cost, minimize the number of unsuccessful exploratory excavations, and reduce unnecessary or unproductive expenditures of time and effort.

  5. A Review of Ground Target Detection and Classification Techniques in Forward Scattering Radars

    Directory of Open Access Journals (Sweden)

    M. E. A. Kanona

    2018-06-01

    Full Text Available This paper presents a review of target detection and classification in forward scattering radar (FSR which is a special state of bistatic radars, designed to detect and track moving targets in the narrow region along the transmitter-receiver base line. FSR has advantages and incredible features over other types of radar configurations. All previous studies proved that FSR can be used as an alternative system for ground target detection and classification. The radar and FSR fundamentals were addressed and classification algorithms and techniques were debated. On the other hand, the current and future applications and the limitations of FSR were discussed.

  6. Low-resolution Airborne Radar Air/ground Moving Target Classification and Recognition

    Directory of Open Access Journals (Sweden)

    Wang Fu-you

    2014-10-01

    Full Text Available Radar Target Recognition (RTR is one of the most important needs of modern and future airborne surveillance radars, and it is still one of the key technologies of radar. The majority of present algorithms are based on wide-band radar signal, which not only needs high performance radar system and high target Signal-to-Noise Ratio (SNR, but also is sensitive to angle between radar and target. Low-Resolution Airborne Surveillance Radar (LRASR in downward-looking mode, slow flying aircraft and ground moving truck have similar Doppler velocity and Radar Cross Section (RCS, leading to the problem that LRASR air/ground moving targets can not be distinguished, which also disturbs detection, tracking, and classification of low altitude slow flying aircraft to solve these issues, an algorithm based on narrowband fractal feature and phase modulation feature is presented for LRASR air/ground moving targets classification. Real measured data is applied to verify the algorithm, the classification results validate the proposed method, helicopters and truck can be well classified, the average discrimination rate is more than 89% when SNR ≥ 15 dB.

  7. Ground penetrating radar system and method for detecting an object on or below a ground surface

    NARCIS (Netherlands)

    De Jongth, R.; Yarovoy, A.; Schukin, A.

    2001-01-01

    Ground penetrating radar system for detecting objects (17) on or below a ground surface (18), comprising at least one transmit antenna (13) having a first foot print (14) at the ground surface, at least one receive antenna (15) having a second foot print (16) at the ground surface, and processing

  8. Fusion of Satellite Multispectral Images Based on Ground-Penetrating Radar (GPR Data for the Investigation of Buried Concealed Archaeological Remains

    Directory of Open Access Journals (Sweden)

    Athos Agapiou

    2017-06-01

    Full Text Available The paper investigates the superficial layers of an archaeological landscape based on the integration of various remote sensing techniques. It is well known in the literature that shallow depths may be rich in archeological remains, which generate different signal responses depending on the applied technique. In this study three main technologies are examined, namely ground-penetrating radar (GPR, ground spectroscopy, and multispectral satellite imagery. The study aims to propose a methodology to enhance optical remote sensing satellite images, intended for archaeological research, based on the integration of ground based and satellite datasets. For this task, a regression model between the ground spectroradiometer and GPR is established which is then projected to a high resolution sub-meter optical image. The overall methodology consists of nine steps. Beyond the acquirement of the in-situ measurements and their calibration (Steps 1–3, various regression models are examined for more than 70 different vegetation indices (Steps 4–5. The specific data analysis indicated that the red-edge position (REP hyperspectral index was the most appropriate for developing a local fusion model between ground spectroscopy data and GPR datasets (Step 6, providing comparable results with the in situ GPR measurements (Step 7. Other vegetation indices, such as the normalized difference vegetation index (NDVI, have also been examined, providing significant correlation between the two datasets (R = 0.50. The model is then projected to a high-resolution image over the area of interest (Step 8. The proposed methodology was evaluated with a series of field data collected from the Vésztő-Mágor Tell in the eastern part of Hungary. The results were compared with in situ magnetic gradiometry measurements, indicating common interpretation results. The results were also compatible with the preliminary archaeological investigations of the area (Step 9. The overall

  9. GPM GROUND VALIDATION NASA MICRO RAIN RADAR (MRR) MC3E V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation NASA Micro Rain Radar (MRR) MC3E dataset was collected by a Micro Rain Radar (MRR), which is a vertically pointing Doppler radar which...

  10. A 10-year Ground-Based Radar Climatology of Convective Penetration of Stratospheric Intrusions and Associated Large-Scale Transport over the CONUS

    Science.gov (United States)

    Homeyer, C. R.

    2017-12-01

    Deep convection reaching the upper troposphere and lower stratosphere (UTLS) and its impact on atmospheric composition through rapid vertical transport of lower troposphere air and stratosphere-troposphere exchange has received increasing attention in the past 5-10 years. Most efforts focused on convection have been directed toward storms that reach and/or penetrate the coincident environmental lapse-rate tropopause. However, convection has also been shown to reach into large-scale stratospheric intrusions (depressions of stratospheric air lying well below the lapse-rate tropopause on the cyclonic side of upper troposphere jet streams). Such convective penetration of stratospheric intrusions is not captured by studies of lapse-rate tropopause-penetrating convection. In this presentation, it will be shown using hourly, high-quality mergers of ground-based radar observations from 2004 to 2013 in the contiguous United States (CONUS) and forward large-scale trajectory analysis that convective penetration of stratospheric intrusions: 1) is more frequent than lapse-rate tropopause-penetrating convection, 2) occurs over a broader area of the CONUS than lapse-rate tropopause-penetrating convection, and 3) can influence the composition of the lower stratosphere through large-scale advection of convectively influenced air to altitudes above the lapse-rate tropopause, which we find to occur for about 8.5% of the intrusion volumes reached by convection.

  11. Fundamentals of ground penetrating radar in environmental and engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Casas, A.; Pinto, V.; Rivero, L. [Barcelona Univ., Barcelona (Spain). Faculty of Geology, Dept. of Geochemistry, Petrology and Geological Prospecting

    2000-12-01

    Ground Penetrating Radar (GPR) is a high frequency electromagnetic sounding technique that has been developed to investigate the shallow subsurface using the contrast of dielectric properties. The method operates on the simple principle that electromagnetic waves, emitted from a transmitter antenna, are reflected from buried objects and detected at another antenna, acting as receiver. GPR data is presented in the form of time-distance plots that are analogous to conventional reflection seismic records, and in fact the method has many similarities to seismic reflection method with a pulse of electromagnetic energy substituting for the elastic (seismic) energy. Nevertheless, the principles and theory of the method are based on the wave equation derived from Maxwell's equations for electromagnetic wave propagation. This paper has been written for tutorial purposes, and it is hoped that it will provide the reader with a good outline of GPR presenting an overview of its theoretical basis, guidelines for interpretation and some practical field examples.

  12. Fundamentals of ground penetrating radar in environmental and engineering applications

    International Nuclear Information System (INIS)

    Casas, A.; Pinto, V.; Rivero, L.

    2000-01-01

    Ground Penetrating Radar (GPR) is a high frequency electromagnetic sounding technique that has been developed to investigate the shallow subsurface using the contrast of dielectric properties. The method operates on the simple principle that electromagnetic waves, emitted from a transmitter antenna, are reflected from buried objects and detected at another antenna, acting as receiver. GPR data is presented in the form of time-distance plots that are analogous to conventional reflection seismic records, and in fact the method has many similarities to seismic reflection method with a pulse of electromagnetic energy substituting for the elastic (seismic) energy. Nevertheless, the principles and theory of the method are based on the wave equation derived from Maxwell's equations for electromagnetic wave propagation. This paper has been written for tutorial purposes, and it is hoped that it will provide the reader with a good outline of GPR presenting an overview of its theoretical basis, guidelines for interpretation and some practical field examples

  13. Accurate Antenna Models in Ground Penetrating Radar Diffraction Tomography

    DEFF Research Database (Denmark)

    Meincke, Peter; Kim, Oleksiy S.

    2002-01-01

    are modeled by their plane-wave receiving and transmitting spectra. We find these spectra numerically for a resistively loaded dipole using the method of moments. Also, we illustrate, through a numerical example, the importance of taking into account the correct antenna pattern in GPR diffraction tomography.......Linear inversion schemes based on the concept of diffraction tomography have proven successful for ground penetrating radar (GPR) imaging. In many GPR surveys, the antennas of the GPR are located close to the air-soil interface and, therefore, it is important to incorporate the presence...... of this interface in the inversion scheme (see Hansen, T.B. and Meincke Johansen, P., IEEE Trans. Geoscience and Remote Sensing, vol.38, p.496-506, 2000). Hansen and Meincke Johansen modeled the antennas as ideal (Hertzian) electric dipoles. Since practical GPR antennas are not ideal, it is of interest...

  14. Fundamental of ground penetrating radar in environmental and engineering applications

    Directory of Open Access Journals (Sweden)

    L. Rivero

    2000-06-01

    Full Text Available Ground Penetrating Radar (GPR is a high frequency electromagnetic sounding technique that has been developed to investigate the shallow subsurface using the contrast of dielectric properties. The method operates on the simple principle that electromagnetic waves, emitted from a transmitter antenna, are reflected from buried objects and detected at another antenna, acting as receiver. GPR data is presented in the form of time-distance plots that are analogous to conventional reflection seismic records, and in fact the method has many similarities to seismic reflection method with a pulse of electromagnetic energy substituting for the elastic (seismic energy. Nevertheless, the principles and theory of the method are based on the wave equation derived from Maxwell's equations for electromagnetic wave propagation. This paper has been written for tutorial purposes, and it is hoped that it will provide the reader with a good outline of GPR presenting an overview of its theoretical basis, guidelines for interpretation and some practical field examples.

  15. Investigation of Underground Hydrocarbon Leakage using Ground Penetrating Radar

    Science.gov (United States)

    Srigutomo, Wahyu; Trimadona; Agustine, Eleonora

    2016-08-01

    Ground Penetrating Radar (GPR) survey was carried out in several petroleum plants to investigate hydrocarbon contamination beneath the surface. The hydrocarbon spills are generally recognized as Light Non-Aqueous Phase Liquids (LNAPL) if the plume of leakage is distributed in the capillary fringe above the water table and as Dense Non-Aqueous Phase Liquids (DNAPL) if it is below the water table. GPR antennas of 200 MHz and 400 MHz were deployed to obtain clear radargrams until 4 m deep. In general, the interpreted radargram sections indicate the presence of surface concrete layer, the compacted silty soill followed by sand layer and the original clayey soil as well as the water table. The presence of hydrocarbon plumes are identified as shadow zones (radar velocity and intensity contrasts) in the radargram that blur the layering pattern with different intensity of reflected signal. Based on our results, the characteristic of the shadow zones in the radargram is controlled by several factors: types of hydrocarbon (fresh or bio-degraded), water moisture in the soil, and clay content which contribute variation in electrical conductivity and dielectric constants of the soil.

  16. Ground-penetrating radar and electromagnetic surveys at the Monroe Crossroads battlefield site, Fort Bragg, North Carolina

    Science.gov (United States)

    Kessler, Richard; Strain, R.E.; Marlowe, J. I.; Currin, K.B.

    1996-01-01

    A ground-penetrating radar survey was conducted at the Monroe Crossroads Battlefield site at Fort Bragg, North Carolina, to determine possible locations of subsurface archaeological features. An electromagnetic survey also was conducted at the site to verify and augment the ground-penetrating radar data. The surveys were conducted over a 67,200-square-foot grid with a grid point spacing of 20 feet. During the ground-penetrating radar survey, 87 subsurface anomalies were detected based on visual inspection of the field records. These anomalies were flagged in the field as they appeared on the ground-penetrating radar records and were located by a land survey. The electromagnetic survey produced two significant readings at ground-penetrating radar anomaly locations. The National Park Service excavated 44 of the 87 anomaly locations at the Civil War battlefield site. Four of these excavations produced significant archaeological features, including one at an abandoned well.

  17. Development of Stepped-Frequency Ground-Penetrating Radar

    DEFF Research Database (Denmark)

    Jakobsen, Kaj Bjarne

    1998-01-01

    The status of the development of a multi-monostatic stepped-frequency ground-penetrating radar (GPR) at The Department of Applied Electronics (IAE), The Technical University of Denmark (DTU) is presented. The feasibility of the used approach is demonstrated by the successful detection of small me...... metallic and non-metallic objects with a diameter of 54 mm buried in loamy soil....

  18. Quantitative analysis of ground penetrating radar data in the Mu Us Sandland

    Science.gov (United States)

    Fu, Tianyang; Tan, Lihua; Wu, Yongqiu; Wen, Yanglei; Li, Dawei; Duan, Jinlong

    2018-06-01

    Ground penetrating radar (GPR), which can reveal the sedimentary structure and development process of dunes, is widely used to evaluate aeolian landforms. The interpretations for GPR profiles are mostly based on qualitative descriptions of geometric features of the radar reflections. This research quantitatively analyzed the waveform parameter characteristics of different radar units by extracting the amplitude and time interval parameters of GPR data in the Mu Us Sandland in China, and then identified and interpreted different sedimentary structures. The results showed that different types of radar units had specific waveform parameter characteristics. The main waveform parameter characteristics of sand dune radar facies and sandstone radar facies included low amplitudes and wide ranges of time intervals, ranging from 0 to 0.25 and 4 to 33 ns respectively, and the mean amplitudes changed gradually with time intervals. The amplitude distribution curves of various sand dune radar facies were similar as unimodal distributions. The radar surfaces showed high amplitudes with time intervals concentrated in high-value areas, ranging from 0.08 to 0.61 and 9 to 34 ns respectively, and the mean amplitudes changed drastically with time intervals. The amplitude and time interval values of lacustrine radar facies were between that of sand dune radar facies and radar surfaces, ranging from 0.08 to 0.29 and 11 to 30 ns respectively, and the mean amplitude and time interval curve was approximately trapezoidal. The quantitative extraction and analysis of GPR reflections could help distinguish various radar units and provide evidence for identifying sedimentary structure in aeolian landforms.

  19. Ground Penetrating Radar for SMART CITIES

    Science.gov (United States)

    Soldovieri, Francesco; Catapano, Ilaria; Gennarelli, Gianluca

    2016-04-01

    The use of monitoring and surveillance technologies is now recognized as a reliable option of the overall smart cities management cycle, for the advantages that they offer in terms of: economically sustainable planning of the ordinary and extraordinary maintenance interventions; situational awareness of possible risks factors in view of a reliable early warning; improvement of the security of the communities especially in public environments. In this frame, the abstract will deal with the recent advances in the development and deployment of radar systems for the urban surveillance, exploitation of the subsurface resources and civil engineering structures. In particular, we will present the recent scientific developments and several examples of use of these systems in operational conditions.

  20. THE IMAGES OF SUBSURFACE TERTIARY – QUARTENARY DEPOSITS BASED ON GROUND PENETRATING RADAR RECORDS OF SUBI KECIL ISLAND COAST, NATUNA DISTRICT, RIAU ARCHIPELAGO PROVINCE

    Directory of Open Access Journals (Sweden)

    Kris Budiono

    2017-07-01

    Full Text Available Subsurface Tertiary to Quaternary deposits from coast of Subi Kecil Island, Natuna Distric, Riau Archipelago Province, were imaged with Ground Penetrating Radar (GPR. The GPR survey was carried out by using GSSI Surveyor III/20 with 270 MHz and 40 MHz of 3200 MLF antennas. GPR data were processed using software GSSI’s RADAN for Windows NT™. The interpretation were done by using the radar facies as a groups of radar reflections. The GPR images of study area can be recoqnized in to several facies such as parallel, sub parallel, chaotic, oblique, mound and reflection-free. The calibration were done with geological data along the coast (cliff and outcrop. Unit A is the uppermost layer which is characterized by continous to non continous pararel reflection, srong reflector and high amplitude and is interpreted as alluvium deposits. Below the unit A is unit B which is characterized by non continous sub parallel, chaotic and mound reflector, strong reflector and high amplitude. Unit C and D (Mio-Oligocene are overlain by unit A and B include chaotic, reflection-free and, locally, discontinuous parallel, oblique mound reflector radar facies, correlatable at the cliff face to massive sands, mostly representing near coastal deposits. These units are bounded by continuous, high amplitude reflections that can be easily correlatable throughout the GPR profiles, serving as important stratigraphic markers. The GPR survey may improve the reconstruction of the depositional environments through the recognition of massive and unconsolidated sand deposits within unit A and B (Holocene. The stratigraphic framework was also improved through the recognition of the discontinuity surface between Units C and D.

  1. How does the ice sheet surface mass balance relate to snowfall? Insights from a ground-based precipitation radar in East Antarctica

    Science.gov (United States)

    Souverijns, Niels; Gossart, Alexandra; Gorodetskaya, Irina V.; Lhermitte, Stef; Mangold, Alexander; Laffineur, Quentin; Delcloo, Andy; van Lipzig, Nicole P. M.

    2018-06-01

    Local surface mass balance (SMB) measurements are crucial for understanding changes in the total mass of the Antarctic Ice Sheet, including its contribution to sea level rise. Despite continuous attempts to decipher mechanisms controlling the local and regional SMB, a clear understanding of the separate components is still lacking, while snowfall measurements are almost absent. In this study, the different terms of the SMB are quantified at the Princess Elisabeth (PE) station in Dronning Maud Land, East Antarctica. Furthermore, the relationship between snowfall and accumulation at the surface is investigated. To achieve this, a unique collocated set of ground-based and in situ remote sensing instrumentation (Micro Rain Radar, ceilometer, automatic weather station, among others) was set up and operated for a time period of 37 months. Snowfall originates mainly from moist and warm air advected from lower latitudes associated with cyclone activity. However, snowfall events are not always associated with accumulation. During 38 % of the observed snowfall cases, the freshly fallen snow is ablated by the wind during the course of the event. Generally, snow storms of longer duration and larger spatial extent have a higher chance of resulting in accumulation on a local scale, while shorter events usually result in ablation (on average 17 and 12 h respectively). A large part of the accumulation at the station takes place when preceding snowfall events were occurring in synoptic upstream areas. This fresh snow is easily picked up and transported in shallow drifting snow layers over tens of kilometres, even when wind speeds are relatively low ( < 7 ms-1). Ablation events are mainly related to katabatic winds originating from the Antarctic plateau and the mountain ranges in the south. These dry winds are able to remove snow and lead to a decrease in the local SMB. This work highlights that the local SMB is strongly influenced by synoptic upstream conditions.

  2. MST radar data-base management

    Science.gov (United States)

    Wickwar, V. B.

    1983-01-01

    Data management for Mesospheric-Stratospheric-Tropospheric, (MST) radars is addressed. An incoherent-scatter radar data base is discussed in terms of purpose, centralization, scope, and nature of the data base management system.

  3. Introduction to ground penetrating radar inverse scattering and data processing

    CERN Document Server

    Persico, Raffaele

    2014-01-01

    This book presents a comprehensive treatment of ground penetrating radar using both forward and inverse scattering mathematical techniques. Use of field data instead of laboratory data enables readers to envision real-life underground imaging; a full color insert further clarifies understanding. Along with considering the practical problem of achieving interpretable underground images, this book also features significant coverage of the problem's mathematical background. This twofold approach provides a resource that will appeal both to application oriented geologists and testing specialists,

  4. Detection of Leaks in Water Mains Using Ground Penetrating Radar

    OpenAIRE

    Alaa Al Hawari; Mohammad Khader; Tarek Zayed; Osama Moselhi

    2016-01-01

    Ground Penetrating Radar (GPR) is one of the most effective electromagnetic techniques for non-destructive non-invasive subsurface features investigation. Water leak from pipelines is the most common undesirable reason of potable water losses. Rapid detection of such losses is going to enhance the use of the Water Distribution Networks (WDN) and decrease threatens associated with water mains leaks. In this study, GPR approach was developed to detect leaks by implementing an appropriate imagin...

  5. VISUAL INSPECTION OF WATER LEAKAGE FROM GROUND PENETRATING RADAR RADARGRAM

    OpenAIRE

    N. N. Halimshah; A. Yusup; Z. Mat Amin; M. D. Ghazalli

    2015-01-01

    Water loss in town and suburban is currently a significant issue which reflect the performance of water supply management in Malaysia. Consequently, water supply distribution system has to be maintained in order to prevent shortage of water supply in an area. Various techniques for detecting a mains water leaks are available but mostly are time-consuming, disruptive and expensive. In this paper, the potential of Ground Penetrating Radar (GPR) as a non-destructive method to correctly and effic...

  6. Measurement of Plane-Wave Spectra of Ground Penetrating Radar Antennas

    DEFF Research Database (Denmark)

    Lenler-Eriksen, Hans-Rudolph; Meincke, Peter

    2005-01-01

    The plane-wave transmitting spectrum of a ground penetrating radar (GPR) loop antenna close to the air-soil interface is measured by means of a probe buried in soil. Probe correction is implemented based upon knowledge about the complex permittivity of the soil and the current distribution...

  7. A 2.5-D Diffraction Tomography Inversion Scheme for Ground Penetrating Radar

    DEFF Research Database (Denmark)

    Meincke, Peter

    1999-01-01

    A new 2.5-D inversion scheme is derived for ground penetrating radar (GPR) that applies to a monostatic fixed-offset measurement configuration. The inversion scheme, which is based upon the first Born approximation and the pseudo-inverse operator, takes rigorously into account the planar air...

  8. Automated Ground Penetrating Radar hyperbola detection in complex environment

    Science.gov (United States)

    Mertens, Laurence; Lambot, Sébastien

    2015-04-01

    Ground Penetrating Radar (GPR) systems are commonly used in many applications to detect, amongst others, buried targets (various types of pipes, landmines, tree roots ...), which, in a cross-section, present theoretically a particular hyperbolic-shaped signature resulting from the antenna radiation pattern. Considering the large quantity of information we can acquire during a field campaign, a manual detection of these hyperbolas is barely possible, therefore we have a real need to have at our disposal a quick and automated detection of these hyperbolas. However, this task may reveal itself laborious in real field data because these hyperbolas are often ill-shaped due to the heterogeneity of the medium and to instrumentation clutter. We propose a new detection algorithm for well- and ill-shaped GPR reflection hyperbolas especially developed for complex field data. This algorithm is based on human recognition pattern to emulate human expertise to identify the hyperbolas apexes. The main principle relies in a fitting process of the GPR image edge dots detected with Canny filter to analytical hyperbolas, considering the object as a punctual disturbance with a physical constraint of the parameters. A long phase of observation of a large number of ill-shaped hyperbolas in various complex media led to the definition of smart criteria characterizing the hyperbolic shape and to the choice of accepted value ranges acceptable for an edge dot to correspond to the apex of a specific hyperbola. These values were defined to fit the ambiguity zone for the human brain and present the particularity of being functional in most heterogeneous media. Furthermore, the irregularity is particularly taken into account by defining a buffer zone around the theoretical hyperbola in which the edge dots need to be encountered to belong to this specific hyperbola. First, the method was tested in laboratory conditions over tree roots and over PVC pipes with both time- and frequency-domain radars

  9. Ground penetrating radar applied to rebar corrosion inspection

    Science.gov (United States)

    Eisenmann, David; Margetan, Frank; Chiou, Chien-Ping T.; Roberts, Ron; Wendt, Scott

    2013-01-01

    In this paper we investigate the use of ground penetrating radar (GPR) to detect corrosion-induced thinning of rebar in concrete bridge structures. We consider a simple pulse/echo amplitude-based inspection, positing that the backscattered response from a thinned rebar will be smaller than the similar response from a fully-intact rebar. Using a commercial 1600-MHz GPR system we demonstrate that, for laboratory specimens, backscattered amplitude measurements can detect a thinning loss of 50% in rebar diameter over a short length. GPR inspections on a highway bridge then identify several rebar with unexpectedly low amplitudes, possibly signaling thinning. To field a practical amplitude-based system for detecting thinned rebar, one must be able to quantify and assess the many factors that can potentially contribute to GPR signal amplitude variations. These include variability arising from the rebar itself (e.g., thinning) and from other factors (concrete properties, antenna orientation and liftoff, etc.). We report on early efforts to model the GPR instrument and the inspection process so as to assess such variability and to optimize inspections. This includes efforts to map the antenna radiation pattern, to predict how backscattered responses will vary with rebar size and location, and to assess detectability improvements via synthetic aperture focusing techniques (SAFT).

  10. Planar Near-Field Measurements of Ground Penetrating Radar Antennas

    DEFF Research Database (Denmark)

    Meincke, Peter; Hansen, Thorkild

    2004-01-01

    Planar near-field measurements are formulated for a general ground penetrating radar (GPR) antenna. A total plane-wave scattering matrix is defined for the system consisting of the GPR antenna and the planar air-soil interface. The transmitting spectrum of the GPR antenna is expressed in terms...... of measurements obtained with a buried probe as the GPR antenna moves over a scan plane on the ground. A numerical example in which the scan plane is finite validates the expressions for the spectrum of the GPR antenna....

  11. Investigations on the sensitivity of a stepped-frequency radar utilizing a vector network analyzer for Ground Penetrating Radar

    Science.gov (United States)

    Seyfried, Daniel; Schubert, Karsten; Schoebel, Joerg

    2014-12-01

    Employing a continuous-wave radar system, with the stepped-frequency radar being one type of this class, all reflections from the environment are present continuously and simultaneously at the receiver. Utilizing such a radar system for Ground Penetrating Radar purposes, antenna cross-talk and ground bounce reflection form an overall dominant signal contribution while reflections from objects buried in the ground are of quite weak amplitude due to attenuation in the ground. This requires a large dynamic range of the receiver which in turn requires high sensitivity of the radar system. In this paper we analyze the sensitivity of our vector network analyzer utilized as stepped-frequency radar system for GPR pipe detection. We furthermore investigate the performance of increasing the sensitivity of the radar by means of appropriate averaging and low-noise pre-amplification of the received signal. It turns out that the improvement in sensitivity actually achievable may differ significantly from theoretical expectations. In addition, we give a descriptive explanation why our appropriate experiments demonstrate that the sensitivity of the receiver is independent of the distance between the target object and the source of dominant signal contribution. Finally, our investigations presented in this paper lead to a preferred setting of operation for our vector network analyzer in order to achieve best detection capability for weak reflection amplitudes, hence making the radar system applicable for Ground Penetrating Radar purposes.

  12. Antenna characteristics and air-ground interface deembedding methods for stepped-frequency ground-penetrating radar measurements

    DEFF Research Database (Denmark)

    Karlsen, Brian; Larsen, Jan; Jakobsen, Kaj Bjarne

    2000-01-01

    The result from field-tests using a Stepped-Frequency Ground Penetrating Radar (SF-GPR) and promising antenna and air-ground deembedding methods for a SF-GPR is presented. A monostatic S-band rectangular waveguide antenna was used in the field-tests. The advantages of the SF-GPR, e.g., amplitude...... and phase information in the SF-GPR signal, is used to deembed the characteristics of the antenna. We propose a new air-to-ground interface deembedding technique based on Principal Component Analysis which enables enhancement of the SF-GPR signal from buried objects, e.g., anti-personal landmines...

  13. INTERPRETATION OF COAL POTENTION USING GROUND PENETRATING RADAR (GPR METHOD

    Directory of Open Access Journals (Sweden)

    Rohmatul Wahidah

    2018-01-01

    Full Text Available Coal exposure founded at Klatak Kebo Ireng village in Besuki Tulungagung precisely in the vicinity of the river. Energy needs is increasing so the coal used for one of alternative energy source that can be used by society. This study was conducted to determine of the potential distribution coal modeling on geological structure. Identification of coal structure is using Ground Penetrating Radar (GPR 2005 it conducted because this method is more suitable for shallow of surveys. The location for taking data is around the river that showed to exposure. There are 5th lines of taken data with length about 50 until 100 meters. Data processing was done using of software Future series 2005. The data displayed with software in the color pattern to obtain based on the constant of dielectric and conductivity. The results of interpretation study are the data indicates that there is a coal on the overall trajectory. Only in 2nd track contain little of coal. The Coal layers are appear in processing the results of data is thickness about 6 at the top. In the area of study also found the cavity (cavity area which contained of several tracks. On the bottom of the track there is a pattern of coal reddish of yellow color which indicates that material contains of minerals.

  14. Visual Inspection of Water Leakage from Ground Penetrating Radar Radargram

    Science.gov (United States)

    Halimshah, N. N.; Yusup, A.; Mat Amin, Z.; Ghazalli, M. D.

    2015-10-01

    Water loss in town and suburban is currently a significant issue which reflect the performance of water supply management in Malaysia. Consequently, water supply distribution system has to be maintained in order to prevent shortage of water supply in an area. Various techniques for detecting a mains water leaks are available but mostly are time-consuming, disruptive and expensive. In this paper, the potential of Ground Penetrating Radar (GPR) as a non-destructive method to correctly and efficiently detect mains water leaks has been examined. Several experiments were designed and conducted to prove that GPR can be used as tool for water leakage detection. These include instrument validation test and soil compaction test to clarify the maximum dry density (MDD) of soil and simulation studies on water leakage at a test bed consisting of PVC pipe burying in sand to a depth of 40 cm. Data from GPR detection are processed using the Reflex 2D software. Identification of water leakage was visually inspected from the anomalies in the radargram based on GPR reflection coefficients. The results have ascertained the capability and effectiveness of the GPR in detecting water leakage which could help avoiding difficulties with other leak detection methods.

  15. VISUAL INSPECTION OF WATER LEAKAGE FROM GROUND PENETRATING RADAR RADARGRAM

    Directory of Open Access Journals (Sweden)

    N. N. Halimshah

    2015-10-01

    Full Text Available Water loss in town and suburban is currently a significant issue which reflect the performance of water supply management in Malaysia. Consequently, water supply distribution system has to be maintained in order to prevent shortage of water supply in an area. Various techniques for detecting a mains water leaks are available but mostly are time-consuming, disruptive and expensive. In this paper, the potential of Ground Penetrating Radar (GPR as a non-destructive method to correctly and efficiently detect mains water leaks has been examined. Several experiments were designed and conducted to prove that GPR can be used as tool for water leakage detection. These include instrument validation test and soil compaction test to clarify the maximum dry density (MDD of soil and simulation studies on water leakage at a test bed consisting of PVC pipe burying in sand to a depth of 40 cm. Data from GPR detection are processed using the Reflex 2D software. Identification of water leakage was visually inspected from the anomalies in the radargram based on GPR reflection coefficients. The results have ascertained the capability and effectiveness of the GPR in detecting water leakage which could help avoiding difficulties with other leak detection methods.

  16. Quantifying reinforced concrete bridge deck deterioration using ground penetrating radar

    Science.gov (United States)

    Martino, Nicole Marie

    Bridge decks are deteriorating at an alarming rate due to corrosion of the reinforcing steel, requiring billions of dollars to repair and replace them. Furthermore, the techniques used to assess the decks don't provide enough quantitative information. In recent years, ground penetrating radar (GPR) has been used to quantify deterioration by comparing the rebar reflection amplitudes to technologies serving as ground truth, because there is not an available amplitude threshold to distinguish healthy from corroded areas using only GPR. The goal of this research is to understand the relationship between GPR and deck deterioration, and develop a model to determine deterioration quantities with GPR alone. The beginning of this research determines that not only is the relationship between GPR and rebar corrosion stronger than the relationship between GPR and delaminations, but that the two are exceptionally correlated (90.2% and 86.6%). Next, multiple bridge decks were assessed with GPR and half-cell potential (HCP). Statistical parameters like the mean and skewness were computed for the GPR amplitudes of each deck, and coupled with actual corrosion quantities based on the HCP measurements to form a future bridge deck model that can be used to assess any deck with GPR alone. Finally, in order to understand exactly which component of rebar corrosion (rust, cracking or chloride) attenuates the GPR data, computational modeling was carried out to isolate each variable. The results indicate that chloride is the major contributor to the rebar reflection attenuation, and that computational modeling can be used to accurately simulate GPR attenuation due to chloride.

  17. Electromagnetic modelling of Ground Penetrating Radar responses to complex targets

    Science.gov (United States)

    Pajewski, Lara; Giannopoulos, Antonis

    2014-05-01

    This work deals with the electromagnetic modelling of composite structures for Ground Penetrating Radar (GPR) applications. It was developed within the Short-Term Scientific Mission ECOST-STSM-TU1208-211013-035660, funded by COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar". The Authors define a set of test concrete structures, hereinafter called cells. The size of each cell is 60 x 100 x 18 cm and the content varies with growing complexity, from a simple cell with few rebars of different diameters embedded in concrete at increasing depths, to a final cell with a quite complicated pattern, including a layer of tendons between two overlying meshes of rebars. Other cells, of intermediate complexity, contain pvc ducts (air filled or hosting rebars), steel objects commonly used in civil engineering (as a pipe, an angle bar, a box section and an u-channel), as well as void and honeycombing defects. One of the cells has a steel mesh embedded in it, overlying two rebars placed diagonally across the comers of the structure. Two cells include a couple of rebars bent into a right angle and placed on top of each other, with a square/round circle lying at the base of the concrete slab. Inspiration for some of these cells is taken from the very interesting experimental work presented in Ref. [1]. For each cell, a subset of models with growing complexity is defined, starting from a simple representation of the cell and ending with a more realistic one. In particular, the model's complexity increases from the geometrical point of view, as well as in terms of how the constitutive parameters of involved media and GPR antennas are described. Some cells can be simulated in both two and three dimensions; the concrete slab can be approximated as a finite-thickness layer having infinite extension on the transverse plane, thus neglecting how edges affect radargrams, or else its finite size can be fully taken into account. The permittivity of concrete can be

  18. Integrity inspection of main access tunnel using ground penetrating radar

    Science.gov (United States)

    Ismail, M. A.; Abas, A. A.; Arifin, M. H.; Ismail, M. N.; Othman, N. A.; Setu, A.; Ahmad, M. R.; Shah, M. K.; Amin, S.; Sarah, T.

    2017-11-01

    This paper discusses the Ground Penetrating Radar (GPR) survey performed to determine the integrity of wall of tunnel at a hydroelectric power generation facility. GPR utilises electromagnetic waves that are transmitted into the medium of survey. Any reflectors in the medium will reflect the transmitted waves and picked up by the GPR antenna. The survey was done using MALA GeoScience RAMAC CUII with 250MHz antenna. Survey was done on the left, the crown and the right walls of the underground tunnels. Distance was measured using wheel encoders. The results of the survey is discussed in this paper.

  19. Ground Penetrating Radar (GPR) for Detection of Underground Objects

    International Nuclear Information System (INIS)

    Amry Amin Abas; Mohd Kamal Shah Shamsuddin; Wan Zainal Abidin; Awang Sarfarudin Awang Putra

    2011-01-01

    Ground Penetrating Radar (GPR) utilizes an electromagnetic microwave that is transmitted into the matter under investigation. Any objects with different dielectric properties from the medium of the matter under investigation will reflect the waves and will be picked up by the receivers embedded in the antenna. We have applied GPR in various application such as concrete inspection, underground utility detection, grave detection, archaeology, oil contamination of soil, soil layer thickness measurement and etc. This paper will give general findings of the application of GPR to provide solutions to the industry and public. The results of the GPR surveys will be discussed. (author)

  20. The variability of tropical ice cloud properties as a function of the large-scale context from ground-based radar-lidar observations over Darwin, Australia

    Science.gov (United States)

    Protat, A.; Delanoë, J.; May, P. T.; Haynes, J.; Jakob, C.; O'Connor, E.; Pope, M.; Wheeler, M. C.

    2011-08-01

    The high complexity of cloud parameterizations now held in models puts more pressure on observational studies to provide useful means to evaluate them. One approach to the problem put forth in the modelling community is to evaluate under what atmospheric conditions the parameterizations fail to simulate the cloud properties and under what conditions they do a good job. It is the ambition of this paper to characterize the variability of the statistical properties of tropical ice clouds in different tropical "regimes" recently identified in the literature to aid the development of better process-oriented parameterizations in models. For this purpose, the statistical properties of non-precipitating tropical ice clouds over Darwin, Australia are characterized using ground-based radar-lidar observations from the Atmospheric Radiation Measurement (ARM) Program. The ice cloud properties analysed are the frequency of ice cloud occurrence, the morphological properties (cloud top height and thickness), and the microphysical and radiative properties (ice water content, visible extinction, effective radius, and total concentration). The variability of these tropical ice cloud properties is then studied as a function of the large-scale cloud regimes derived from the International Satellite Cloud Climatology Project (ISCCP), the amplitude and phase of the Madden-Julian Oscillation (MJO), and the large-scale atmospheric regime as derived from a long-term record of radiosonde observations over Darwin. The vertical variability of ice cloud occurrence and microphysical properties is largest in all regimes (1.5 order of magnitude for ice water content and extinction, a factor 3 in effective radius, and three orders of magnitude in concentration, typically). 98 % of ice clouds in our dataset are characterized by either a small cloud fraction (smaller than 0.3) or a very large cloud fraction (larger than 0.9). In the ice part of the troposphere three distinct layers characterized by

  1. Earth-Space Link Attenuation Estimation via Ground Radar Kdp

    Science.gov (United States)

    Bolen, Steven M.; Benjamin, Andrew L.; Chandrasekar, V.

    2003-01-01

    A method of predicting attenuation on microwave Earth/spacecraft communication links, over wide areas and under various atmospheric conditions, has been developed. In the area around the ground station locations, a nearly horizontally aimed polarimetric S-band ground radar measures the specific differential phase (Kdp) along the Earth-space path. The specific attenuation along a path of interest is then computed by use of a theoretical model of the relationship between the measured S-band specific differential phase and the specific attenuation at the frequency to be used on the communication link. The model includes effects of rain, wet ice, and other forms of precipitation. The attenuation on the path of interest is then computed by integrating the specific attenuation over the length of the path. This method can be used to determine statistics of signal degradation on Earth/spacecraft communication links. It can also be used to obtain real-time estimates of attenuation along multiple Earth/spacecraft links that are parts of a communication network operating within the radar coverage area, thereby enabling better management of the network through appropriate dynamic routing along the best combination of links.

  2. Integrated, Dual Orthogonal Antennas for Polarimetric Ground Penetrating Radar

    Science.gov (United States)

    Pauli, Mario; Wiesbeck, Werner

    2015-04-01

    Ground penetrating radar systems are mostly equipped with single polarized antennas, for example with single linear polarization or with circular polarization. The radiated waves are partly reflected at the ground surface and very often the penetrating waves are distorted in their polarization. The distortion depends on the ground homogeneity and the orientation of the antennas relative to the ground structure. The received signals from the reflecting objects may most times only be classified according to their coverage and intensity. This makes the recognition of the objects difficult or impossible. In airborne and spaceborne Remote Sensing the systems are meanwhile mostly equipped with front ends with dual orthogonal polarized antennas for a full polarimetric operation. The received signals, registered in 2x2 scattering matrices according to co- and cross polarization, are processed for the evaluation of all features of the targets. Ground penetrating radars could also profit from the scientific results of Remote Sensing. The classification of detected objects for their structure and orientation requires more information in the reflected signal than can be measured with a single polarization [1, 2]. In this paper dual linear, orthogonal polarized antennas with a common single, frequency independent phase center, are presented [3]. The relative bandwidth of these antennas can be 1:3, up to 1:4. The antenna is designed to work in the frequency range between 3 GHz and 11 GHz, but can be easily adapted to the GPR frequency range by scaling. The size of the antenna scaled for operation in typical GPR frequencies would approximately be 20 by 20 cm2. By the implementation in a dielectric carrier it could be reduced in size if required. The major problem for ultra wide band, dual polarized antennas is the frequency independent feed network, realizing the required phase shifts. For these antennas a network, which is frequency independent over a wide range, has been

  3. Ground clutter cancellation in incoherent radars: solutions for EISCAT Svalbard radar

    Directory of Open Access Journals (Sweden)

    T. Turunen

    2000-09-01

    Full Text Available Incoherent scatter radars measure ionosphere parameters using modified Thomson scatter from free electrons in the target (see e.g. Hagfors, 1997. The integrated cross section of the ionospheric scatterers is extremely small and the measurements can easily be disturbed by signals returned by unwanted targets. Ground clutter signals, entering via the antenna side lobes, can render measurements at the nearest target ranges totally impossible. The EISCAT Svalbard Radar (ESR, which started measurements in 1996, suffers from severe ground clutter and the ionosphere cannot be measured in any simple manner at ranges less than about 120–150 km, depending on the modulation employed. If the target and clutter signals have different, and clearly identifiable, properties then, in principle, there are always ways to eliminate the clutter. In incoherent scatter measurements, differences in the coherence times of the wanted and unwanted signals can be used for clutter cancellation. The clutter cancellation must be applied to all modulations, usually alternating codes in modern experiments, used for shorter ranges. Excellent results have been obtained at the ESR using a simple pulse-to-pulse clutter subtraction method, but there are also other possibilities.Key words: Radio science (ionospheric physics; signal processing; instruments and techniques

  4. Sensitivity of Spaceborne and Ground Radar Comparison Results to Data Analysis Methods and Constraints

    Science.gov (United States)

    Morris, Kenneth R.; Schwaller, Mathew

    2011-01-01

    With the availability of active weather radar observations from space from the Precipitation Radar (PR) on board the Tropical Rainfall Measuring Mission (TR.MM) satellite, numerous studies have been performed comparing PR reflectivity and derived rain rates to similar observations from ground-based weather radars (GR). These studies have used a variety of algorithms to compute matching PR and GR volumes for comparison. Most studies have used a fixed 3-dimensional Cartesian grid centered on the ground radar, onto which the PR and GR data are interpolated using a proprietary approach and/or commonly available GR analysis software (e.g., SPRINT, REORDER). Other studies have focused on the intersection of the PR and GR viewing geometries either explicitly or using a hybrid of the fixed grid and PR/GR common fields of view. For the Dual-Frequency Precipitation Radar (DPR) of the upcoming Global Precipitation Measurement (GPM) mission, a prototype DPR/GR comparison algorithm based on similar TRMM PR data has been developed that defines the common volumes in terms of the geometric intersection of PR and GR rays, where smoothing of the PR and GR data are minimized and no interpolation is performed. The PR and GR volume-averaged reflectivity values of each sample volume are accompanied by descriptive metadata, for attributes including the variability and maximum of the reflectivity within the sample volume, and the fraction of range gates in the sample average having reflectivity values above an adjustable detection threshold (typically taken to be 18 dBZ for the PR). Sample volumes are further characterized by rain type (Stratiform or Convective), proximity to the melting layer, underlying surface (land/water/mixed), and the time difference between the PR and GR observations. The mean reflectivity differences between the PR and GR can differ between data sets produced by the different analysis methods; and for the GPM prototype, by the type of constraints and

  5. UAV-based Radar Sounding of Antarctic Ice

    Science.gov (United States)

    Leuschen, Carl; Yan, Jie-Bang; Mahmood, Ali; Rodriguez-Morales, Fernando; Hale, Rick; Camps-Raga, Bruno; Metz, Lynsey; Wang, Zongbo; Paden, John; Bowman, Alec; Keshmiri, Shahriar; Gogineni, Sivaprasad

    2014-05-01

    We developed a compact radar for use on a small UAV to conduct measurements over the ice sheets in Greenland and Antarctica. It operates at center frequencies of 14 and 35 MHz with bandwidths of 1 MHz and 4 MHz, respectively. The radar weighs about 2 kgs and is housed in a box with dimensions of 20.3 cm x 15.2 cm x 13.2 cm. It transmits a signal power of 100 W at a pulse repletion frequency of 10 kHz and requires average power of about 20 W. The antennas for operating the radar are integrated into the wings and airframe of a small UAV with a wingspan of 5.3 m. We selected the frequencies of 14 and 35 MHz based on previous successful soundings of temperate ice in Alaska with a 12.5 MHz impulse radar [Arcone, 2002] and temperate glaciers in Patagonia with a 30 MHz monocycle radar [Blindow et al., 2012]. We developed the radar-equipped UAV to perform surveys over a 2-D grid, which allows us to synthesize a large two-dimensional aperture and obtain fine resolution in both the along- and cross-track directions. Low-frequency, high-sensitivity radars with 2-D aperture synthesis capability are needed to overcome the surface and volume scatter that masks weak echoes from the ice-bed interface of fast-flowing glaciers. We collected data with the radar-equipped UAV on sub-glacial ice near Lake Whillans at both 14 and 35 MHz. We acquired data to evaluate the concept of 2-D aperture synthesis and successfully demonstrated the first successful sounding of ice with a radar on an UAV. We are planning to build multiple radar-equipped UAVs for collecting fine-resolution data near the grounding lines of fast-flowing glaciers. In this presentation we will provide a brief overview of the radar and UAV, as well as present results obtained at both 14 and 35 MHz. Arcone, S. 2002. Airborne-radar stratigraphy and electrical structure of temperate firn: Bagley Ice Field, Alaska, U.S.A. Journal of Glaciology, 48, 317-334. Blindow, N., C. Salat, and G. Casassa. 2012. Airborne GPR sounding of

  6. A Ground-Based Doppler Radar and Micropulse Lidar Forward Simulator for GCM Evaluation of Arctic Mixed-Phase Clouds: Moving Forward Towards an Apples-to-apples Comparison of Hydrometeor Phase

    Science.gov (United States)

    Lamer, K.; Fridlind, A. M.; Ackerman, A. S.; Kollias, P.; Clothiaux, E. E.

    2017-12-01

    An important aspect of evaluating Artic cloud representation in a general circulation model (GCM) consists of using observational benchmarks which are as equivalent as possible to model output in order to avoid methodological bias and focus on correctly diagnosing model dynamical and microphysical misrepresentations. However, current cloud observing systems are known to suffer from biases such as limited sensitivity, and stronger response to large or small hydrometeors. Fortunately, while these observational biases cannot be corrected, they are often well understood and can be reproduced in forward simulations. Here a ground-based millimeter wavelength Doppler radar and micropulse lidar forward simulator able to interface with output from the Goddard Institute for Space Studies (GISS) ModelE GCM is presented. ModelE stratiform hydrometeor fraction, mixing ratio, mass-weighted fall speed and effective radius are forward simulated to vertically-resolved profiles of radar reflectivity, Doppler velocity and spectrum width as well as lidar backscatter and depolarization ratio. These forward simulated fields are then compared to Atmospheric Radiation Measurement (ARM) North Slope of Alaska (NSA) ground-based observations to assess cloud vertical structure (CVS). Model evalution of Arctic mixed-phase cloud would also benefit from hydrometeor phase evaluation. While phase retrieval from synergetic observations often generates large uncertainties, the same retrieval algorithm can be applied to observed and forward-simulated radar-lidar fields, thereby producing retrieved hydrometeor properties with potentially the same uncertainties. Comparing hydrometeor properties retrieved in exactly the same way aims to produce the best apples-to-apples comparisons between GCM ouputs and observations. The use of a comprenhensive ground-based forward simulator coupled with a hydrometeor classification retrieval algorithm provides a new perspective for GCM evaluation of Arctic mixed

  7. Global Research Patterns on Ground Penetrating Radar (GPR)

    Science.gov (United States)

    Gizzi, Fabrizio Terenzio; Leucci, Giovanni

    2018-05-01

    The article deals with the analysis of worldwide research patterns concerning ground penetrating radar (GPR) during 1995-2014. To do this, the Thomson Reuters' Science Citation Index Expanded (SCI-EXPANDED) and the Social Sciences Citation Index accessed via the Web of Science Core Collection were the two bibliographic databases taken as a reference. We pay attention to the document typology and language, the publication trend and citations, the subject categories and journals, the collaborations between authors, the productivity of the authors, the most cited articles, the countries and the institutions involved, and other hot issues. Concerning the main research subfields involving GPR use, there were five, physical-mathematical, sedimentological-stratigraphical, civil engineering/engineering geology/cultural heritage, hydrological (HD), and glaciological (GL), subfields.

  8. Advanced ground-penetrating, imaging radar for bridge inspection

    International Nuclear Information System (INIS)

    Warhus, J.P.; Nelson, S.D.; Mast, J.E.; Johansson, E.M.

    1994-01-01

    During FY-93, the authors continued with development and experimental evaluation of components and system concepts aimed at improving ground-penetrating imaging radar (GPIR) for nondestructive evaluation of bridge decks and other high-value concrete structures. They developed and implemented a laboratory test bed, including features to facilitate component testing antenna system configuration evaluation, and collection of experimental data from realistic test objects. In addition, they developed pulse generators and antennas for evaluation and use in antenna configuration studies. This project was part of a cooperative effort with the Computational Electronics and Electromagnetics and Remote Imaging and Signal Engineering Thrust Areas, which contributed signal- and image-processing algorithm and software development and modeling support

  9. Mapping the Antarctic grounding line with CryoSat-2 radar altimetry

    Science.gov (United States)

    Bamber, J. L.; Dawson, G. J.

    2017-12-01

    The grounding line, where grounded ice begins to float, is the boundary at which the ocean has the greatest influence on the ice-sheet. Its position and dynamics are critical in assessing the stability of the ice-sheet, for mass budget calculations and as an input into numerical models. The most reliable approaches to map the grounding line remotely are to measure the limit of tidal flexure of the ice shelf using differential synthetic aperture radar interferometry (DInSAR) or ICESat repeat-track measurements. However, these methods are yet to provide satisfactory spatial and temporal coverage of the whole of the Antarctic grounding zone. It has not been possible to use conventional radar altimetry to map the limit of tidal flexure of the ice shelf because it performs poorly near breaks in slope, commonly associated with the grounding zone. The synthetic aperture radar interferometric (SARin) mode of CryoSat-2, performs better over steeper margins of the ice sheet and allows us to achieve this. The SARin mode combines "delay Doppler" processing with a cross-track interferometer, and enables us to use elevations based on the first return (point of closest approach or POCA) and "swath processed" elevations derived from the time-delayed waveform beyond the first return, to significantly improve coverage. Here, we present a new method to map the limit of tidal motion from a combination of POCA and swath data. We test this new method on the Siple Coast region of the Ross Ice Shelf, and the mapped grounding line is in good agreement with previous observations from DinSAR and ICESat measurements. There is, however, an approximately constant seaward offset between these methods and ours, which we believe is due to the poorer precision of CryoSat-2. This new method has improved the coverage of the grounding zone across the Siple Coast, and can be applied to the rest of Antarctica.

  10. The ground based plan

    International Nuclear Information System (INIS)

    1989-01-01

    The paper presents a report of ''The Ground Based Plan'' of the United Kingdom Science and Engineering Research Council. The ground based plan is a plan for research in astronomy and planetary science by ground based techniques. The contents of the report contains a description of:- the scientific objectives and technical requirements (the basis for the Plan), the present organisation and funding for the ground based programme, the Plan, the main scientific features and the further objectives of the Plan. (U.K.)

  11. Civil Engineering Applications of Ground Penetrating Radar in Finland

    Science.gov (United States)

    Pellinen, Terhi; Huuskonen-Snicker, Eeva; Olkkonen, Martta-Kaisa; Eskelinen, Pekka

    2014-05-01

    Ground penetrating radar (GPR) has been used in Finland since 1980's for civil engineering applications. First applications in this field were road surveys and dam inspections. Common GPR applications in road surveys include the thickness evaluation of the pavement, subgrade soil evaluation and evaluation of the soil moisture and frost susceptibility. Since the 1990's, GPR has been used in combination with other non-destructive testing (NDT) methods in road surveys. Recently, more GPR applications have been adopted, such as evaluating bridges, tunnels, railways and concrete elements. Nowadays, compared with other countries GPR is relatively widely used in Finland for road surveys. Quite many companies, universities and research centers in Finland have their own GPR equipment and are involved in the teaching and research of the GPR method. However, further research and promotion of the GPR techniques are still needed since GPR could be used more routinely. GPR has been used to evaluate the air void content of asphalt pavements for years. Air void content is an important quality measure of pavement condition for both the new and old asphalt pavements. The first Finnish guideline was released in 1999 for the method. Air void content is obtained from the GPR data by measuring the dielectric value as continuous record. To obtain air void content data, few pavement cores must be taken for calibration. Accuracy of the method is however questioned because there are other factors that affect the dielectric value of the asphalt layer, in addition to the air void content. Therefore, a research project is currently carried out at Aalto University in Finland. The overall objective is to investigate if the existing GPR technique used in Finland is accurate enough to be used as QC/QA tool in assessing the compaction of asphalt pavements. The project is funded by the Finnish Transport Agency. Further research interests at Aalto University include developing new microwave asphalt

  12. GPM GROUND VALIDATION PAWNEE RADAR MC3E V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Pawnee radar data for the Midlatitude Continental Convective Clouds Experiment (MC3E) held in Oklahoma were collected on May 24, 2011 to support the CHILL radar...

  13. Stakeholder needs for ground penetrating radar utility location

    Science.gov (United States)

    Thomas, A. M.; Rogers, C. D. F.; Chapman, D. N.; Metje, N.; Castle, J.

    2009-04-01

    In the UK alone there are millions of miles of underground utilities with often inaccurate, incomplete, or non-existent location records that cause significant health and safety problems for maintenance personnel, together with the potential for large, unnecessary, social and financial costs for their upkeep and repair. This has led to increasing use of Ground Penetrating Radar (GPR) for utility location, but without detailed consideration of the degree of location accuracy required by stakeholders — i.e. all those directly involved in streetworks ranging from utility owners to contractors and surveyors and government departments. In order to ensure that stakeholder requirements are incorporated into a major new UK study, entitled Mapping the Underworld, a questionnaire has been used to determine the current and future utility location accuracy requirements. The resulting data indicate that stakeholders generally require location tolerances better than 100 mm at depths usually extending down to 3 m, and more occasionally to 5 m, below surface level, providing significant challenges to GPR if their needs are to be met in all ground conditions. As well as providing much useful data on stakeholder needs, these data are also providing a methodology for assessment of GPR utility location in terms of the factor most important to them — the degree to which the equipment provides location within their own accuracy requirements.

  14. ONKALO EDZ-measurements using ground penetrating radar (GPR) method

    Energy Technology Data Exchange (ETDEWEB)

    Silvast, M.; Wiljanen, B. (Roadscanners Oy, Rovaniemi (Finland))

    2008-09-15

    This report presents pilot project results from various Ground Penetrating Radar (GPR) tests performed on bedrock in ONKALO, the research tunnel system being built for the final disposal of spent nuclear fuel (in Finland). In recent years the GPR technology for structure inspection has improved to faster systems and higher frequencies. Processing and interpretation software has been developed for better visualization of processed data. GPR is a powerful non-destructive testing method with major advantages such as fast measurement speed and continuous survey lines. The purpose of the tests was to determine the capacity of GPR in identifying the Excavation Damaged or Disturbed Zone (EDZ). Topics included comparison of different types of GPR systems and antennas in select locations in the tunnel system and data presentation. High quality GPR data was obtained from all systems that were used on surfaces without concrete or steel reinforcement. Data processed using Geo Doctor software, which enables integrated analysis of available datasets on a single screen, provided promising results. (orig.)

  15. ONKALO EDZ-measurements using ground penetrating radar (GPR) method

    International Nuclear Information System (INIS)

    Silvast, M.; Wiljanen, B.

    2008-09-01

    This report presents pilot project results from various Ground Penetrating Radar (GPR) tests performed on bedrock in ONKALO, the research tunnel system being built for the final disposal of spent nuclear fuel (in Finland). In recent years the GPR technology for structure inspection has improved to faster systems and higher frequencies. Processing and interpretation software has been developed for better visualization of processed data. GPR is a powerful non-destructive testing method with major advantages such as fast measurement speed and continuous survey lines. The purpose of the tests was to determine the capacity of GPR in identifying the Excavation Damaged or Disturbed Zone (EDZ). Topics included comparison of different types of GPR systems and antennas in select locations in the tunnel system and data presentation. High quality GPR data was obtained from all systems that were used on surfaces without concrete or steel reinforcement. Data processed using Geo Doctor software, which enables integrated analysis of available datasets on a single screen, provided promising results. (orig.)

  16. Using Ground Radar Interferometry for Precise Determining of Deformation and Vertical Deflection of Structures

    Science.gov (United States)

    Talich, Milan

    2017-12-01

    The paper describes possibilities of the relatively new technics - ground based radar interferometry for precise determining of deformation of structures. Special focus on the vertical deflection of bridge structures and on the horizontal movements of high-rise buildings and structural objects is presented. The technology of ground based radar interferometry can be used in practice to the contactless determination of deformations of structures with accuracy up to 0.01 mm in real time. It is also possible in real time to capture oscillations of the object with a frequency up to 50 Hz. Deformations can be determined simultaneously in multiple places of the object, for example a bridge structure at points distributed on the bridge deck at intervals of one or more meters. This allows to obtain both overall and detailed information about the properties of the structure during the dynamic load and monitoring the impact of movements either individual vehicles or groups. In the case of high-rise buildings, it is possible to monitor the horizontal vibration of the whole object at its different height levels. It is possible to detect and determine the compound oscillations that occur in some types of buildings. Then prevent any damage or even disasters in these objects. In addition to the necessary theory basic principles of using radar interferometry for determining of deformation of structures are given. Practical examples of determining deformation of bridge structures, water towers reservoirs, factory chimneys and wind power plants are also given. The IBIS-S interferometric radar of the Italian IDS manufacturer was used for the measurements.

  17. A Machine Learning-based Rainfall System for GPM Dual-frequency Radar

    Science.gov (United States)

    Tan, H.; Chandrasekar, V.; Chen, H.

    2017-12-01

    Precipitation measurement produced by the Global Precipitation Measurement (GPM) Dual-frequency Precipitation Radar (DPR) plays an important role in researching the water circle and forecasting extreme weather event. Compare with its predecessor - Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR), GRM DPR measures precipitation in two different frequencies (i.e., Ku and Ka band), which can provide detailed information on the microphysical properties of precipitation particles, quantify particle size distribution and quantitatively measure light rain and falling snow. This paper presents a novel Machine Learning system for ground-based and space borne radar rainfall estimation. The system first trains ground radar data for rainfall estimation using rainfall measurements from gauges and subsequently uses the ground radar based rainfall estimates to train GPM DPR data in order to get space based rainfall product. Therein, data alignment between space DPR and ground radar is conducted using the methodology proposed by Bolen and Chandrasekar (2013), which can minimize the effects of potential geometric distortion of GPM DPR observations. For demonstration purposes, rainfall measurements from three rain gauge networks near Melbourne, Florida, are used for training and validation purposes. These three gauge networks, which are located in Kennedy Space Center (KSC), South Florida Water Management District (SFL), and St. Johns Water Management District (STJ), include 33, 46, and 99 rain gauge stations, respectively. Collocated ground radar observations from the National Weather Service (NWS) Weather Surveillance Radar - 1988 Doppler (WSR-88D) in Melbourne (i.e., KMLB radar) are trained with the gauge measurements. The trained model is then used to derive KMLB radar based rainfall product, which is used to train GPM DPR data collected from coincident overpasses events. The machine learning based rainfall product is compared against the GPM standard products

  18. 47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.

    Science.gov (United States)

    2010-10-01

    ..., fire fighting, emergency rescue, scientific research, commercial mining, or construction. (1) Parties... radars and wall imaging systems. 15.509 Section 15.509 Telecommunication FEDERAL COMMUNICATIONS... ground penetrating radars and wall imaging systems. (a) The UWB bandwidth of an imaging system operating...

  19. GPM GROUND VALIDATION AIRBORNE SECOND GENERATION PRECIPITATION RADAR (APR-2) GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Airborne Second Generation Precipitation Radar (APR-2) GCPEx dataset was collected during the GPM Cold-season Precipitation Experiment...

  20. GPM GROUND VALIDATION MCGILL W-BAND RADAR GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation McGill W-Band Radar GCPEx dataset was collected from February 1, 2012 to February 29, 2012 at the CARE site in Ontario, Canada as a part of...

  1. GPM GROUND VALIDATION DUAL POLARIZED C-BAND DOPPLER RADAR KING CITY GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Dual Polarized C-Band Doppler Radar King City GCPEx dataset has special Range Height Indicator (RHI) and sector scans of several dual...

  2. Use of Ground Penetrating Radar for Locating Contraband Aboard Ocean Going Vessels: Feasibility Study

    National Research Council Canada - National Science Library

    Llopis, Jose

    2001-01-01

    Ground Penetrating Radar (GPR) surveys were conducted over various stockpiled materials at the Alabama state Docks located in Mobile, AL, to determine whether GPR is a viable method for rapidly detecting contraband materials...

  3. Advies voor de toepassing van ground-penetrating radar bij de inventarisatie van de grondwaterdynamiek

    NARCIS (Netherlands)

    Knotters, M.

    2001-01-01

    Ground-penetrating radar (GPR) biedt mogelijk een nauwkeurig alternatief voor arbeidsintensieve metingen van de grondwaterstand in boorgaten. De GPR-metingen kunnen als hulpinformatie dienen bij geostatistische interpolatie van grondwaterstanden. Op basis van literatuurstudie en verkenning van het

  4. GPM GROUND VALIDATION NASA S-BAND DUAL POLARIMETRIC (NPOL) DOPPLER RADAR IFLOODS V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation NASA S-Band Dual Polarimetric (NPOL) Doppler Radar IFloodS data set was collected from April 30, 2013 to June 16, 2013 near Traer, Iowa as...

  5. A controlled monitoring study of simulated clandestine graves using 3D ground penetrating radar

    CSIR Research Space (South Africa)

    van Schoor, Michael

    2017-06-01

    Full Text Available A controlled three-dimensional ground penetrating radar monitoring study over simulated clandestine graves was conducted near Pretoria, South Africa, in which the detectability of graves as a function of post-burial interval was assessed...

  6. Deep Ground Penetrating Radar (GPR) WIPL-D Models of Buried Sub-Surface Radiators

    National Research Council Canada - National Science Library

    Norgard, John D; Wicks, Michael C; Musselman, Randy L

    2005-01-01

    .... A new Ground Penetrating Radar (GPR) concept is proposed in this paper to use subsurface radiators, delivered as earth penetrating non-explosive, electronic e-bombs, as the source of strong radiated transmissions for GPR experiments...

  7. Ground-penetrating radar study of the Rahivere peat bog, eastern Estonia

    Directory of Open Access Journals (Sweden)

    Jüri Plado

    2011-03-01

    Full Text Available The current case study presents results of the ground-penetrating radar (GPR profiling at one of the Saadjärve drumlin field interstitial troughs, the Rahivere bog, eastern Estonia. The study was conducted in order to identify the bog morphology, and the thickness and geometry of the peat body. The method was also used to describe the applicability of GPR in the evaluation of the peat deposit reserve as the Rahivere bog belongs among the officially registered peat reserves. Fourteen GPR profiles, ~ 100 m apart and oriented perpendicular to the long axis of the depression, covering the bog and its surrounding areas, were acquired. In order to verify the radar image interpretation as well as to evaluate the velocity of electromagnetic waves in peat, a common source configuration was utilized and thirteen boreholes were drilled on the GPR profiles. A mean value of 0.036 m ns–1 corresponding to relative dielectric permittivity of 69.7 was used for the time–depth conversion. Radar images reveal major reflection from the peat–soil interface up to a depth of about 4 m, whereas drillings showed a maximum thickness of 4.5 m of peat. Minor reflections appear from the upper peat and mineral soil. According to the borehole data, undecomposed peat is underlain by decomposed one, but identifying them by GPR is complicated. Mineral soil consists of glaciolimnic silty sand in the peripheral areas of the trough, overlain by limnic clay in the central part. The calculated peat volumes (1 200 000 m3 were found to exceed the earlier estimation (979 000 m3 that was based solely on drilling data. Ground-penetrating radar, as a method that allows mapping horizontal continuity of the sub-peat interface in a non-destructive way, was found to provide detailed information for evaluating peat depth and extent.

  8. Joint ACE ground penetrating radar antenna test facility at the Technical University of Denmark

    DEFF Research Database (Denmark)

    Lenler-Eriksen, Hans-Rudolph; Meincke, Peter; Sarri, A.

    2005-01-01

    A ground penetrating radar (GPR) antenna test facility, established within the ACE network at the Technical University of Denmark (DTU), is described. Examples of results from the facility obtained from measurements of eight different GPR antennas are presented.......A ground penetrating radar (GPR) antenna test facility, established within the ACE network at the Technical University of Denmark (DTU), is described. Examples of results from the facility obtained from measurements of eight different GPR antennas are presented....

  9. Creating soil moisture maps based on radar satellite imagery

    Science.gov (United States)

    Hnatushenko, Volodymyr; Garkusha, Igor; Vasyliev, Volodymyr

    2017-10-01

    The presented work is related to a study of mapping soil moisture basing on radar data from Sentinel-1 and a test of adequacy of the models constructed on the basis of data obtained from alternative sources. Radar signals are reflected from the ground differently, depending on its properties. In radar images obtained, for example, in the C band of the electromagnetic spectrum, soils saturated with moisture usually appear in dark tones. Although, at first glance, the problem of constructing moisture maps basing on radar data seems intuitively clear, its implementation on the basis of the Sentinel-1 data on an industrial scale and in the public domain is not yet available. In the process of mapping, for verification of the results, measurements of soil moisture obtained from logs of the network of climate stations NOAA US Climate Reference Network (USCRN) were used. This network covers almost the entire territory of the United States. The passive microwave radiometers of Aqua and SMAP satellites data are used for comparing processing. In addition, other supplementary cartographic materials were used, such as maps of soil types and ready moisture maps. The paper presents a comparison of the effect of the use of certain methods of roughening the quality of radar data on the result of mapping moisture. Regression models were constructed showing dependence of backscatter coefficient values Sigma0 for calibrated radar data of different spatial resolution obtained at different times on soil moisture values. The obtained soil moisture maps of the territories of research, as well as the conceptual solutions about automation of operations of constructing such digital maps, are presented. The comparative assessment of the time required for processing a given set of radar scenes with the developed tools and with the ESA SNAP product was carried out.

  10. Radar-based hail detection

    Czech Academy of Sciences Publication Activity Database

    Skripniková, Kateřina; Řezáčová, Daniela

    2014-01-01

    Roč. 144, č. 1 (2014), s. 175-185 ISSN 0169-8095 R&D Projects: GA ČR(CZ) GAP209/11/2045; GA MŠk LD11044 Institutional support: RVO:68378289 Keywords : hail detection * weather radar * hail damage risk Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.844, year: 2014 http://www.sciencedirect.com/science/article/pii/S0169809513001804

  11. Ground penetrating radar utilization in exploring inadequate concrete covers in a new bridge deck

    Directory of Open Access Journals (Sweden)

    Md. Istiaque Hasan

    2014-01-01

    Full Text Available The reinforced concrete cast in place four span deck of a concrete bridge near Roanoke, Texas, was recently completed. Due to possible construction errors, it was suspected that the concrete covers in the deck did not conform to drawings and specifications. A full scale non-destructive evaluation of the concrete covers was carried out using ground penetrating radar (GPR equipment. Cover values were determined from the radargram generated from the scan. The estimated covers were plotted on contour maps. Migration data can substitute the drilling based ground truth data without compromising the concrete cover estimations, except for areas with very high cover values. Areas with high water content may result in inaccurate concrete dielectric constants. Based on the results, significant retrofitting of the bridge deck, such as additional overlay, was recommended.

  12. GPM GROUND VALIDATION DUAL-FREQUENCY DUAL-POLARIZED DOPPLER RADAR (D3R) IFLOODS V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Dual-frequency Dual-polarized Doppler Radar (D3R) IFloodS data set contain radar reflectivity and doppler velocity measurements. The D3R...

  13. GPM GROUND VALIDATION CHILL RADAR MC3E V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The CHILL radar data for the Midlatitude Continental Convective Clouds Experiment (MC3E) held in Oklahoma were collected while the NASA ER-2 aircraft conducted a...

  14. Ground Radar Polarimetric Observations of High-Frequency Earth-Space Communication Links

    Science.gov (United States)

    Bolen, Steve; Chandrasekar, V.; Benjamin, Andrew

    2002-01-01

    Strategic roadmaps for NASA's Human Exploration and Development of Space (REDS) enterprise support near-term high-frequency communication systems that provide moderate to high data rates with dependable service. Near-earth and human planetary exploration will baseline Ka-Band, but may ultimately require the use of even higher frequencies. Increased commercial demand on low-frequency earth-space bands has also led to increased interest in the use of higher frequencies in regions like K u - and K,- band. Data is taken from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR), which operates at 13.8 GHz, and the true radar reflectivity profile is determined along the PR beam via low-frequency ground based polarimetric observations. The specific differential phase (Kdp) is measured along the beam and a theoretical model is used to determine the expected specific attenuation (k). This technique, called the k-Kdp method, uses a Fuzzy-Logic model to determine the hydrometeor type along the PR beam from which the appropriate k-Kdp relationship is used to determine k and, ultimately, the total path-integrated attenuation (PIA) on PR measurements. Measurements from PR and the NCAR S-POL radar were made during the TEFLUN-B experiment that took place near Melbourne, FL in 1998, and the TRMM-LBA campaign near Ji-Parana, Brazil in 1999.

  15. SEA ICE THICKNESS MEASUREMENT BY GROUND PENETRATING RADAR FOR GROUND TRUTH OF MICROWAVE REMOTE SENSING DATA

    Directory of Open Access Journals (Sweden)

    M. Matsumoto

    2018-04-01

    Full Text Available Observation of sea ice thickness is one of key issues to understand regional effect of global warming. One of approaches to monitor sea ice in large area is microwave remote sensing data analysis. However, ground truth must be necessary to discuss the effectivity of this kind of approach. The conventional method to acquire ground truth of ice thickness is drilling ice layer and directly measuring the thickness by a ruler. However, this method is destructive, time-consuming and limited spatial resolution. Although there are several methods to acquire ice thickness in non-destructive way, ground penetrating radar (GPR can be effective solution because it can discriminate snow-ice and ice-sea water interface. In this paper, we carried out GPR measurement in Lake Saroma for relatively large area (200 m by 300 m, approximately aiming to obtain grand truth for remote sensing data. GPR survey was conducted at 5 locations in the area. The direct measurement was also conducted simultaneously in order to calibrate GPR data for thickness estimation and to validate the result. Although GPR Bscan image obtained from 600MHz contains the reflection which may come from a structure under snow, the origin of the reflection is not obvious. Therefore, further analysis and interpretation of the GPR image, such as numerical simulation, additional signal processing and use of 200 MHz antenna, are required to move on thickness estimation.

  16. Non-invasive monitoring of below ground cassava storage root bulking by ground penetrating radar technology

    Science.gov (United States)

    Ruiz Vera, U. M.; Larson, T. H.; Mwakanyamale, K. E.; Grennan, A. K.; Souza, A. P.; Ort, D. R.; Balikian, R. J.

    2017-12-01

    Agriculture needs a new technological revolution to be able to meet the food demands, to overcome weather and natural hazards events, and to monitor better crop productivity. Advanced technologies used in other fields have recently been applied in agriculture. Thus, imagine instrumentation has been applied to phenotype above-ground biomass and predict yield. However, the capability to monitor belowground biomass is still limited. There are some existing technologies available, for example the ground penetrating radar (GPR) which has been used widely in the area of geology and civil engineering to detect different kind of formations under the ground without the disruption of the soil. GPR technology has been used also to monitor tree roots but as yet not crop roots. Some limitation are that the GPR cannot discern roots smaller than 2 cm in diameter, but it make it feasible for application in tuber crops like Cassava since harvest diameter is greater than 4 cm. The objective of this research is to test the availability to use GPR technology to monitor the growth of cassava roots by testing this technique in the greenhouse and in the field. So far, results from the greenhouse suggest that GPR can detect mature roots of cassava and this data could be used to predict biomass.

  17. Sea Ice Thickness Measurement by Ground Penetrating Radar for Ground Truth of Microwave Remote Sensing Data

    Science.gov (United States)

    Matsumoto, M.; Yoshimura, M.; Naoki, K.; Cho, K.; Wakabayashi, H.

    2018-04-01

    Observation of sea ice thickness is one of key issues to understand regional effect of global warming. One of approaches to monitor sea ice in large area is microwave remote sensing data analysis. However, ground truth must be necessary to discuss the effectivity of this kind of approach. The conventional method to acquire ground truth of ice thickness is drilling ice layer and directly measuring the thickness by a ruler. However, this method is destructive, time-consuming and limited spatial resolution. Although there are several methods to acquire ice thickness in non-destructive way, ground penetrating radar (GPR) can be effective solution because it can discriminate snow-ice and ice-sea water interface. In this paper, we carried out GPR measurement in Lake Saroma for relatively large area (200 m by 300 m, approximately) aiming to obtain grand truth for remote sensing data. GPR survey was conducted at 5 locations in the area. The direct measurement was also conducted simultaneously in order to calibrate GPR data for thickness estimation and to validate the result. Although GPR Bscan image obtained from 600MHz contains the reflection which may come from a structure under snow, the origin of the reflection is not obvious. Therefore, further analysis and interpretation of the GPR image, such as numerical simulation, additional signal processing and use of 200 MHz antenna, are required to move on thickness estimation.

  18. Suitability of ground penetrating radar for locating large fractures

    Energy Technology Data Exchange (ETDEWEB)

    Heikkinen, E. [Poeyry Finland Oy, Vantaa (Finland); Kantia, P. [Roadscanners Oy, Rovaniemi (Finland)

    2011-12-15

    Posiva Oy is responsible for preparation of final disposal of spent nuclear fuel in Olkiluoto. The knowledge about existing network of fractures is important for the safety and feasibility of the final repository. The bedrock properties essential for safety case are analysed in investigations of Rock Suitability Criteria (RSC). One subtask in RSC is avoidance of large (long) fractures adjacent to disposal holes. The long fractures have been defined in tunnel mapping to indicate tunnel cross-cutting features (TCF) or full perimeter intersections (FPI). Suitability of ground penetrating radar (GPR) method for locating large fractures was assessed. The assessment used data measured with 100 MHz and 270 MHz radar tool on ONKALO access tunnel right-hand wall, chainage 3344 - 3578 and on TKU-3 niche floor chainage 15 - 55 and 25 - 67 m. GPR images were processed to enhance reflections and suppress interference and diffractions. Images were placed on measurement position in 3D presentation software. The tunnel wall and floor mapping data was presented along with GPR images. A review of observed GPR reflections, and assessment of visibility of large fractures, was drawn on basis of 3D view examination. The GPR tool can detect reflections from cleaned and dry rock floor and wall. Depth of penetration is 8-12 m for 270 MHz antenna. The antenna has high resolution. Coupling on rock surface is good, which suppresses ringing and interference. Penetration is 20-24 m for 100 MHz antenna, which has a trade off of higher interference due to weaker contact to surface caused by large antenna. There are observed many kind of reflecting surfaces and diffractors in the images, like for example lithological contacts and high grade shearing, and also fractures. Proper manner to apply the method is to use raw and processed images during geological mapping to confirm the origin of reflections. Reflections deemed to be caused by fractures are useful to be compiled to 3D model objects. The

  19. Suitability of ground penetrating radar for locating large fractures

    International Nuclear Information System (INIS)

    Heikkinen, E.; Kantia, P.

    2011-12-01

    Posiva Oy is responsible for preparation of final disposal of spent nuclear fuel in Olkiluoto. The knowledge about existing network of fractures is important for the safety and feasibility of the final repository. The bedrock properties essential for safety case are analysed in investigations of Rock Suitability Criteria (RSC). One subtask in RSC is avoidance of large (long) fractures adjacent to disposal holes. The long fractures have been defined in tunnel mapping to indicate tunnel cross-cutting features (TCF) or full perimeter intersections (FPI). Suitability of ground penetrating radar (GPR) method for locating large fractures was assessed. The assessment used data measured with 100 MHz and 270 MHz radar tool on ONKALO access tunnel right-hand wall, chainage 3344 - 3578 and on TKU-3 niche floor chainage 15 - 55 and 25 - 67 m. GPR images were processed to enhance reflections and suppress interference and diffractions. Images were placed on measurement position in 3D presentation software. The tunnel wall and floor mapping data was presented along with GPR images. A review of observed GPR reflections, and assessment of visibility of large fractures, was drawn on basis of 3D view examination. The GPR tool can detect reflections from cleaned and dry rock floor and wall. Depth of penetration is 8-12 m for 270 MHz antenna. The antenna has high resolution. Coupling on rock surface is good, which suppresses ringing and interference. Penetration is 20-24 m for 100 MHz antenna, which has a trade off of higher interference due to weaker contact to surface caused by large antenna. There are observed many kind of reflecting surfaces and diffractors in the images, like for example lithological contacts and high grade shearing, and also fractures. Proper manner to apply the method is to use raw and processed images during geological mapping to confirm the origin of reflections. Reflections deemed to be caused by fractures are useful to be compiled to 3D model objects. The

  20. Ground Penetrating Radar employment for searching ancient cisterns.

    Science.gov (United States)

    Semeraro, Grazia; Notario, Corrado; Persico, Raffaele

    2017-04-01

    Ground Penetrating Radar technology and methodology can provide support for the archaeological research. In particular, investigations in archaeological sites [1-3] and monuments of historical interest [4-6] have provided in many cases information of interest about the presence, the size, the shape and the depth of embedded anomalies, that can range from foundations to crypts, or also walled passages, walled doors, embedded voids or reinforcement bars, fractures and so on. In this contribution we will focus on the possibility to identify ancient cisterns with the aid of a GPR prospection. In particular, the attention will be focused on Messapic cisterns. The Messapians were a population that used to reside in the southern part of the Apulia region (the so called Salento), Their remains dates back from the 8th century B.C. up to the Roman conquest, in the 3rd century B.C. They used to build cisterns for gathering the rain water, both for drinking and for agricultural purposes. The shape of the cisterns can be quite different from case to case, and rarely they are found empty. Rether, in most cases the remains shows a structure with the roof collapsed and filled up with loose materials, which makes their identification with a GPR a challenging issue. At the conference, the results and the interpretation of GPR data gathered in the two Messapic sites of San Vito dei Normanni and Cavallino (both in the Salento area) will be shown and discussed. References 1) R. Lasaponara, G. Leucci, N. Masini, R. Persico, Investigating archaeological looting using satellite images and GEORADAR: the experience in Lambayeque in North Peru, Journal of Archaeological Science, vol. 42, pp. 216-230, 2014. 2) R. Castaldo, L. Crocco, M. Fedi, B. Garofalo, R. Persico, A. Rossi, F. Soldovieri, GPR Microwave Tomography for Diagnostic of Archaeological Sites: the Case of a high-way construction in Pontecagnano (Southern Italy), Archaeological Prospection, vol. 16, pp. 203-217, 2009. 3) L. Matera

  1. Three Decades of Volume Change of a Small Greenlandic Glacier Using Ground Penetrating Radar, Structure from Motion, and Aerial Photogrammetry

    DEFF Research Database (Denmark)

    Marcer, M.; Stentoft, Peter Alexander; Bjerre, Elisa

    2017-01-01

    Glaciers in the Arctic are losing mass at an increasing rate. Here we use surface topography derived from Structure from Motion (SfM) and ice volume from ground penetrating radar (GPR) to describe the 2014 state of Aqqutikitsoq glacier (2.85 km) on Greenland's west coast. A photogrammetrically...... derived 1985 digital elevation model (DEM) was subtracted from a 2014 DEM obtained using land-based SfM to calculate geodetic glacier mass balance. Furthermore, a detailed 2014 ground penetrating radar survey was performed to assess ice volume. From 1985 to 2014, the glacier has lost 49.8 ± 9.4 10 m...... aerial photography. To address this issue, surface elevation in low contrast areas was measured manually at point locations and interpolated using a universal kriging approach. We conclude that ground-based SfM is well suited to establish high-quality DEMs of smaller glaciers. Provided favorable...

  2. Detecting and characterizing unroofed caves by ground penetrating radar

    Science.gov (United States)

    Čeru, Teja; Šegina, Ela; Knez, Martin; Benac, Čedomir; Gosar, Andrej

    2018-02-01

    The bare karst surface in the southeastern part of Krk Island (Croatia) is characterized by different surface karst features, such as valley-like shallow linear depressions and partially or fully sediment-filled depressions of various shapes and sizes. They were noticed due to locally increased thickness of sediment and enhanced vegetation but had not yet been systematically studied and defined. Considering only the geometry of the investigated surface features and the rare traces of cave environments detected by field surveys, it was unclear which processes (surface karstification and/or speleogenesis) contributed most to their formation. The low-frequency ground penetrating radar (GPR) method using a special 50 MHz RTA antenna was applied to study and describe these karst features. Three study sites were chosen and 5 km of GPR profiles were positioned to include various surface features. The results obtained from the GPR investigation lead to the following conclusions: (1) an increased thickness of sediment was detected in all the investigated depressions indicating their considerable depth; (2) areas between different depressions expressed as attenuated zones in GPR images reveal their interconnection; (3) transitions between surface and underground features are characterized by a collapsed passage visible in the GPR data; and (4) an underground continuation of surface valley-like depressions was detected, proving the speleogenetic origin of such features. Subsurface information obtained using GPR indicates that the valley-like depressions, irregular depressions completely or partially filled with sediment, and some dolines are associated with a nearly 4 km-long unroofed cave and developed as a result of karst denudation. In the regional context, these results suggest long-lasting karstification processes in the area, in contrast to the pre-karstic fluvial phase previously assumed to have occurred here. This research is the first application of the GPR method to

  3. NAPL detection with ground-penetrating radar (Invited)

    Science.gov (United States)

    Bradford, J. H.

    2013-12-01

    Non-polar organic compounds are common contaminants and are collectively referred to as nonaqueous-phase liquids (NAPLs). NAPL contamination problems occur in virtually every environment on or near the earth's surface and therefore a robust suite of geophysical tools is required to accurately characterize NAPL spills and monitor their remediation. NAPLs typically have low dielectric permittivity and low electric conductivity relative to water. Thus a zone of anomalous electrical properties often occurs when NAPL displaces water in the subsurface pore space. Such electric property anomalies make it possible to detect NAPL in the subsurface using electrical or electromagnetic geophysical methods including ground-penetrating radar (GPR). The GPR signature associated with the presence of NAPL is manifest in essentially three ways. First, the decrease in dielectric permittivity results in increased EM propagation velocity. Second, the decrease in permittivity can significantly change reflectivity. Finally, electric conductivity anomalies lead to anomalous GPR signal attenuation. The conductivity anomaly may be either high or low depending on the state of NAPL degradation, but with either high or low conductivity, GPR attenuation analysis can be a useful tool for identifying contaminated-zones. Over the past 15 years I have conducted numerous modeling, laboratory, and field tests to investigate the ability to use GPR to measure NAPL induced anomalies. The emphasis of this work has been on quantitative analysis to characterize critical source zone parameters such as NAPL concentration. Often, the contaminated zones are below the conventional resolution of the GPR signal and require thin layer analysis. Through a series of field examples, I demonstrate 5 key GPR analysis tools that can help identify and quantify NAPL contaminants. These tools include 1) GPR velocity inversion from multi-fold data, 2) amplitude vs offset analysis, 3) spectral decomposition, 4) frequency

  4. Plasma-based radar cross section reduction

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book presents a comprehensive review of plasma-based stealth, covering the basics, methods, parametric analysis, and challenges towards the realization of the idea. The concealment of aircraft from radar sources, or stealth, is achieved through shaping, radar absorbing coatings, engineered materials, or plasma, etc. Plasma-based stealth is a radar cross section (RCS) reduction technique associated with the reflection and absorption of incident electromagnetic (EM) waves by the plasma layer surrounding the structure. A plasma cloud covering the aircraft may give rise to other signatures such as thermal, acoustic, infrared, or visual. Thus it is a matter of concern that the RCS reduction by plasma enhances its detectability due to other signatures. This needs a careful approach towards the plasma generation and its EM wave interaction. The book starts with the basics of EM wave interactions with plasma, briefly discuss the methods used to analyze the propagation characteristics of plasma, and its generatio...

  5. On thin ice: ground penetrating radar improves safety for seismic crews in frigid arctic darkness

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.

    2002-02-01

    The fact that workers are pushing the limits of the Canadian Arctic's ice is more than act of faith; it is the result of rapidly advancing technologies that are taking the guesswork, and therefore the risk, out of icetop exploration. The most important element to improve safety in recent years has been the increased use of ground penetrating radar (GPR) which allows the most detailed images yet of ice thickness. It is an absolutely invaluable tool for allowing vehicles to drive along the ice roads up the rivers and offshore, with significantly reduced risk for the people involved. GPR is an essential part of the equipment usually tied into global positioning system (GPS) and and geographic information system (GIS). The collected GPS and GPR data are loaded into the workstation and merged to produce a GIS map where the colored map of ice thickness is overlaid over satellite image or aerial photographs. Ground penetrating radar was first used in Austria in 1929 to measure glacial ice thickness. It fell into disuse during the 1950s but the technology advanced rapidly in subsequent years; it was used as part of Apollo 17's lunar sounder experiment in 1972. It is particularly useful in northern Arctic regions to determine near-surface thickness. With pipeline developments in the active planning stages, measuring the thickness of ice is more vital than ever; investors will not commit to multi-billion dollar projects before the resource base is fully delineated.

  6. Radar Rainfall Bias Correction based on Deep Learning Approach

    Science.gov (United States)

    Song, Yang; Han, Dawei; Rico-Ramirez, Miguel A.

    2017-04-01

    Radar rainfall measurement errors can be considerably attributed to various sources including intricate synoptic regimes. Temperature, humidity and wind are typically acknowledged as critical meteorological factors in inducing the precipitation discrepancies aloft and on the ground. The conventional practices mainly use the radar-gauge or geostatistical techniques by direct weighted interpolation algorithms as bias correction schemes whereas rarely consider the atmospheric effects. This study aims to comprehensively quantify those meteorological elements' impacts on radar-gauge rainfall bias correction based on a deep learning approach. The deep learning approach employs deep convolutional neural networks to automatically extract three-dimensional meteorological features for target recognition based on high range resolution profiles. The complex nonlinear relationships between input and target variables can be implicitly detected by such a scheme, which is validated on the test dataset. The proposed bias correction scheme is expected to be a promising improvement in systematically minimizing the synthesized atmospheric effects on rainfall discrepancies between radar and rain gauges, which can be useful in many meteorological and hydrological applications (e.g., real-time flood forecasting) especially for regions with complex atmospheric conditions.

  7. A new ground-penetrating radar system for remote site characterization

    International Nuclear Information System (INIS)

    Davis, K.C.; Sandness, G.A.

    1994-08-01

    The cleanup of waste burial sites and military bombing ranges involves the risk of exposing field personnel to toxic chemicals, radioactive materials, or unexploded munitions. Time-consuming and costly measures are required to provide protection from those hazards. Therefore, there is a growing interest in developing remotely controlled sensors and sensor platforms that can be employed in site characterization surveys. A specialized ground-penetrating radar has been developed to operate on a remotely controlled vehicle for the non-intrusive subsurface characterization of buried waste sites. Improved radar circuits provide enhanced performance, and an embedded microprocessor dynamically optimizes operation. The radar unit is packaged to survive chemical contamination and decontamination

  8. Detection and delineation of underground septic tanks in sandy terrain using ground penetrating radar

    Science.gov (United States)

    Omolaiye, Gabriel Efomeh; Ayolabi, Elijah A.

    2010-09-01

    A ground penetrating radar (GPR) survey was conducted on the Lekki Peninsula, Lagos State, Nigeria. The primary target of the survey was the delineation of underground septic tanks (ST). A total of four GPR profiles were acquired on the survey site using Ramac X3M GPR equipment with a 250MHz antenna, chosen based on the depth of interest and resolution. An interpretable depth of penetration of 4.5m below the surface was achieved after processing. The method accurately delineated five underground ST. The tops of the ST were easily identified on the radargram based on the strong-amplitude anomalies, the length and the depths to the base of the ST were estimated with 99 and 73 percent confidence respectively. The continuous vertical profiles provide uninterrupted subsurface data along the lines of traverse, while the non-intrusive nature makes it an ideal tool for the accurate mapping and delineation of underground utilities.

  9. The 183-WSL Fast Rain Rate Retrieval Algorithm. Part II: Validation Using Ground Radar Measurements

    Science.gov (United States)

    Laviola, Sante; Levizzani, Vincenzo

    2014-01-01

    The Water vapour Strong Lines at 183 GHz (183-WSL) algorithm is a method for the retrieval of rain rates and precipitation type classification (convectivestratiform), that makes use of the water vapor absorption lines centered at 183.31 GHz of the Advanced Microwave Sounding Unit module B (AMSU-B) and of the Microwave Humidity Sounder (MHS) flying on NOAA-15-18 and NOAA-19Metop-A satellite series, respectively. The characteristics of this algorithm were described in Part I of this paper together with comparisons against analogous precipitation products. The focus of Part II is the analysis of the performance of the 183-WSL technique based on surface radar measurements. The ground truth dataset consists of 2.5 years of rainfall intensity fields from the NIMROD European radar network which covers North-Western Europe. The investigation of the 183-WSL retrieval performance is based on a twofold approach: 1) the dichotomous statistic is used to evaluate the capabilities of the method to identify rain and no-rain clouds; 2) the accuracy statistic is applied to quantify the errors in the estimation of rain rates.The results reveal that the 183-WSL technique shows good skills in the detection of rainno-rain areas and in the quantification of rain rate intensities. The categorical analysis shows annual values of the POD, FAR and HK indices varying in the range 0.80-0.82, 0.330.36 and 0.39-0.46, respectively. The RMSE value is 2.8 millimeters per hour for the whole period despite an overestimation in the retrieved rain rates. Of note is the distribution of the 183-WSL monthly mean rain rate with respect to radar: the seasonal fluctuations of the average rainfalls measured by radar are reproduced by the 183-WSL. However, the retrieval method appears to suffer for the winter seasonal conditions especially when the soil is partially frozen and the surface emissivity drastically changes. This fact is verified observing the discrepancy distribution diagrams where2the 183-WSL

  10. Simulation model study of limitation on the locating distance of a ground penetrating radar; Chichu tansa radar no tansa kyori genkai ni kansuru simulation model no kochiku

    Energy Technology Data Exchange (ETDEWEB)

    Nakauchi, T; Tsunasaki, M; Kishi, M; Hayakawa, H [Osaka Gas Co. Ltd., Osaka (Japan)

    1996-10-01

    Various simulations were carried out under various laying conditions to obtain the limitation of locating distance for ground penetrating radar. Recently, ground penetrating radar has been remarked as location technology of obstacles such as the existing buried objects. To enhance the theoretical model (radar equation) of a maximum locating distance, the following factors were examined experimentally using pulse ground penetrating radar: ground surface conditions such as asphalt pavement, diameter of buried pipes, material of buried pipes, effect of soil, antenna gain. The experiment results well agreed with actual field experiment ones. By adopting the antenna gain and effect of the ground surface, the more practical simulation using underground models became possible. The maximum locating distance was more improved by large antenna than small one in actual field. It is assumed that large antenna components contributed to improvement of gain and reduction of attenuation during passing through soil. 5 refs., 12 figs.

  11. Use of Ground Penetrating Radar at the FAA's National Airport Pavement Test Facility

    Science.gov (United States)

    Injun, Song

    2015-04-01

    The Federal Aviation Administration (FAA) in the United States has used a ground-coupled Ground Penetrating Radar (GPR) at the National Airport Pavement Test Facility (NAPTF) since 2005. One of the primary objectives of the testing at the facility is to provide full-scale pavement response and failure information for use in airplane landing gear design and configuration studies. During the traffic testing at the facility, a GSSI GPR system was used to develop new procedures for monitoring Hot Mix Asphalt (HMA) pavement density changes that is directly related to pavement failure. After reviewing current setups for data acquisition software and procedures for identifying different pavement layers, dielectric constant and pavement thickness were selected as dominant parameters controlling HMA properties provided by GPR. A new methodology showing HMA density changes in terms of dielectric constant variations, called dielectric sweep test, was developed and applied in full-scale pavement test. The dielectric constant changes were successfully monitored with increasing airplane traffic numbers. The changes were compared to pavement performance data (permanent deformation). The measured dielectric constants based on the known HMA thicknesses were also compared with computed dielectric constants using an equation from ASTM D4748-98 Standard Test Method for Determining the Thickness of Bound Pavement Layers Using Short-Pulse Radar. Six inches diameter cylindrical cores were taken after construction and traffic testing for the HMA layer bulk specific gravity. The measured bulk specific gravity was also compared to monitor HMA density changes caused by aircraft traffic conditions. Additionally this presentation will review the applications of the FAA's ground-coupled GPR on embedded rebar identification in concrete pavement, sewer pipes in soil, and gage identifications in 3D plots.

  12. On the radar cross section (RCS) prediction of vehicles moving on the ground

    International Nuclear Information System (INIS)

    Sabihi, Ahmad

    2014-01-01

    As readers should be aware, Radar Cross Section depends on the factors such as: Wave frequency and polarization, Target dimension, angle of ray incidence, Target’s material and covering, Type of radar system as monostatic or bistatic, space in which contains target and propagating waves, and etc. Having moved or stationed in vehicles can be effective in RCS values. Here, we investigate effective factors in RCS of moving targets on the ground or sea. Image theory in electromagnetic applies to be taken into account RCS of a target over the ground or sea

  13. On the radar cross section (RCS) prediction of vehicles moving on the ground

    Energy Technology Data Exchange (ETDEWEB)

    Sabihi, Ahmad [Department of Mathematical Sciences, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2014-12-10

    As readers should be aware, Radar Cross Section depends on the factors such as: Wave frequency and polarization, Target dimension, angle of ray incidence, Target’s material and covering, Type of radar system as monostatic or bistatic, space in which contains target and propagating waves, and etc. Having moved or stationed in vehicles can be effective in RCS values. Here, we investigate effective factors in RCS of moving targets on the ground or sea. Image theory in electromagnetic applies to be taken into account RCS of a target over the ground or sea.

  14. Design of Wireless Automatic Synchronization for the Low-Frequency Coded Ground Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Zhenghuan Xia

    2015-01-01

    Full Text Available Low-frequency coded ground penetrating radar (GPR with a pair of wire dipole antennas has some advantages for deep detection. Due to the large distance between the two antennas, the synchronization design is a major challenge of implementing the GPR system. This paper proposes a simple and stable wireless automatic synchronization method based on our developed GPR system, which does not need any synchronization chips or modules and reduces the cost of the hardware system. The transmitter omits the synchronization preamble and pseudorandom binary sequence (PRBS at an appropriate time interval, while receiver automatically estimates the synchronization time and receives the returned signal from the underground targets. All the processes are performed in a single FPGA. The performance of the proposed synchronization method is validated with experiment.

  15. Ground penetrating radar using a microwave radiated from laser-induced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, H; Tanaka, K A [Graduate School of Engineering and Institute of Laser Engineering, Suita, Osaka University (Japan); Yamaura, M; Shimada, Y; Fujita, M [Institute for Laser Technology, Suita, Osaka (Japan)], E-mail: nakajima-h@ile.osaka-u.ac.jp

    2008-05-01

    A plasma column radiates a microwave to surroundings when generated with laser irradiation. Using such a microwave, we are able to survey underground objects and architectures from a remote place. In this paper, the microwave radiated from a plasma column induced by an intense laser ({approx} 10{sup 9} W/cm{sup 2}) were measured. Additionally, a proof test of this method was performed by searching an underground aluminum disk (26 cm in diameter, 1 cm in depth, and 1 m apart from a receiving antenna). As the result, the characteristics of the radiated microwave were clarified, and strong echoes corresponding to the edges of an aluminum disk were found. Based on these results, the feasibility of a ground penetrating radar was verified.

  16. An Iterative Approach to Ground Penetrating Radar at the Maya Site of Pacbitun, Belize

    Directory of Open Access Journals (Sweden)

    Sheldon Skaggs

    2016-09-01

    Full Text Available Ground penetrating radar (GPR surveys provide distinct advantages for archaeological prospection in ancient, complex, urban Maya sites, particularly where dense foliage or modern debris may preclude other remote sensing or geophysical techniques. Unidirectional GPR surveys using a 500 MHz shielded antenna were performed at the Middle Preclassic Maya site of Pacbitun, Belize. The survey in 2012 identified numerous linear and circular anomalies between 1 m and 2 m deep. Based on these anomalies, one 1 m × 4 m unit and three smaller units were excavated in 2013. These test units revealed a curved plaster surface not previously found at Pacbitun. Post-excavation, GPR data were reprocessed to best match the true nature of excavated features. Additional GPR surveys oriented perpendicular to the original survey confirmed previously detected anomalies and identified new anomalies. The excavations provided information on the sediment layers in the survey area, which allowed better identification of weak radar reflections of the surfaces of a burnt, Middle Preclassic temple in the northern end of the survey area. Additional excavations of the area in 2014 and 2015 revealed it to be a large square structure, which was named El Quemado.

  17. Ground-Penetrating Radar Prospecting in the Peinan Archaeological Site, Taiwan

    Directory of Open Access Journals (Sweden)

    Lun-Tao Tong

    2013-01-01

    Full Text Available The Peinan archaeological site is the largest prehistoric village in Taiwan. Only small-scale pits are allowed for research purposes because the Peinan site is protected by the Cultural Heritage Preservation Act. Careful selection of the pit locations is crucial for future archaeological research at this site. In this study, a ground-penetrating radar (GPR survey was applied near the stone pillar to understand the GPR signatures of the subsurface remains. Seven GPR signatures were categorized based on the radar characters shown on the GPR image. A detailed GPR survey with dense parallel survey lines was subsequently conducted in the area of northern extent of the onsite exhibition to map the subsurface ancient buildings. The results were verified by two test pits, which indicate that the distribution of the subsurface building structures can be well recognized from GPR depth slices. It will be very helpful for setting proper pits priorities for future archaeological research, and for making proper design of the new onsite exhibition.

  18. Estimation of past sea-level variations based on ground-penetrating radar mapping of beach-ridges - preliminary results from Feddet, Faxe Bay, eastern Denmark

    DEFF Research Database (Denmark)

    Hede, Mikkel Ulfeldt; Nielsen, Lars; Clemmensen, Lars B

    2011-01-01

    Estimates of past sea-level variations based on different methods and techniques have been presented in a range of studies, including interpretation of beach ridge characteristics. In Denmark, Holocene beach ridge plains have been formed during the last c. 7700 years, a period characterised by both...... isostatic uplift and changes in eustatic sea-level, and therefore represent an archive of past relative sea-level variations. Here, we present preliminary results from investigation of beach ridges from Feddet, a small peninsula located in Faxe Bay (Baltic Sea) in the eastern part of Denmark. Feddet has...... been chosen as a key-locality in this project, as it is located relatively close to the current 0-isobase of isostatic rebound. GPR reflection data have been acquired with shielded 250 MHz Sensors & software antennae along a number of profile lines across beach ridge and swale structures of the Feddet...

  19. Design of an ultra-wideband ground-penetrating radar system using impulse radiating antennas

    NARCIS (Netherlands)

    Rhebergen, J.B.; Zwamborn, A.P.M.; Giri, D.V.

    1998-01-01

    At TNO-FEL, one of the research programs is to explore the use of ultra-wideband (UWB) electromagnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g. land mines). In the present paper we describe

  20. Improving mine recognition through processing and Dempster-Shafer fusion of ground-penetrating radar data

    NARCIS (Netherlands)

    Milisavljević, N.; Bloch, I.; Broek, S.P. van den; Acheroy, M.

    2003-01-01

    A methodfor modeling andcombination of measures extractedfrom a ground-penetrating radar (GPR) in terms of belief functions within the Dempster-Shafer framework is presentedandillustratedon a real GPR data set. A starting point in the analysis is a preprocessed C-scan of a sand-lane containing some

  1. Ground penetrating radar images of selected fluvial deposits in the Netherlands

    NARCIS (Netherlands)

    Berghe, J. van den; Overmeeren, R.A. van

    1999-01-01

    Ground penetrating radar (GPR) surveys have been carried out in order to characterise reflection patterns and to assess the method's potential for imaging palaeofluvial sediments in the Mass-Rhine former confluence area in the southern Netherlands. The results show that the deposits of meandering,

  2. The ACE-DTU Planar Near-Field Ground Penetrating Radar Antenna Test Facility

    DEFF Research Database (Denmark)

    Lenler-Eriksen, Hans-Rudolph; Meincke, Peter

    2004-01-01

    The ACE-DTU planar near-field ground penetrating radar (GPR) antenna test facility is used to measure the plane-wave transmitting spectrum of a GPR loop antenna close to the air-soil interface by means of a probe buried in soil. Probe correction is implemented using knowledge about the complex...

  3. Design of an ultra-wideband ground-penetrating radar system using impulse radiating antennas

    NARCIS (Netherlands)

    Rhebergen, J.B.; Zwamborn, A.P.M.; Giri, D.V.

    1999-01-01

    At TNO-FEL, one of the research programs is to explore the use of ultra-wideband (UWB) electromagnetic fields in a bi-static ground-penetrating radar (GPR) system for the detection, location and identification of buried items of unexploded ordnance (e.g. land mines). In the present paper we describe

  4. Efficient Calculation of Born Scattering for Fixed-Offset Ground-Penetrating Radar Surveys

    DEFF Research Database (Denmark)

    Meincke, Peter

    2007-01-01

    A formulation is presented for efficient calculation of linear electromagnetic scattering by buried penetrable objects, as involved in the analysis of fixed-offset ground-penetrating radar (GPR) systems. The actual radiation patterns of the GPR antennas are incorporated in the scattering...

  5. Ground penetrating radar (GPR) detects fine roots of agricultural crops in the field

    Science.gov (United States)

    Xiuwei Liu; Xuejun Dong; Qingwu Xue; Daniel I. Leskovar; John Jifon; John R. Butnor; Thomas Marek

    2018-01-01

    Aim Ground penetrating radar (GPR) as a non-invasive technique is widely used in coarse root detection. However, the applicability of the technique to detect fine roots of agricultural crops is unknown. The objective of this study was to assess the feasibility of utilizing GPR to detect fine roots in the field.

  6. Sedimentology and Ground-Penetrating Radar Characteristics of a Pleistocene Sandur Deposit

    DEFF Research Database (Denmark)

    Olsen, Henrik; Andreasen, Frank Erik

    1995-01-01

    -upward lithology, terminating with a jökulhlaup episode characterized by large compound dune migration and slack-water draping. Mapping of a more than 200 m long well exposed pitwall and ground-penetrating radar measurements in a 50 × 200 m grid along the pitwall made it possible to outline the three...

  7. Ground penetrating radar images of selected fluvial deposits in the Netherlands.

    NARCIS (Netherlands)

    Vandenberghe, J.; van Overmeeren, R.A.

    1999-01-01

    Ground penetrating radar (GPR) surveys have been carried out in order to characterise reflection patterns and to assess the method's potential for imaging palaeofluvial sediments in the Mass-Rhine former confluence area in the southern Netherlands. The results show that the deposits of meandering,

  8. Uncertainty of Flood Forecasting Based on Radar Rainfall Data Assimilation

    Directory of Open Access Journals (Sweden)

    Xinchi Chen

    2016-01-01

    Full Text Available Precipitation is the core data input to hydrological forecasting. The uncertainty in precipitation forecast data can lead to poor performance of predictive hydrological models. Radar-based precipitation measurement offers advantages over ground-based measurement in the quantitative estimation of temporal and spatial aspects of precipitation, but errors inherent in this method will still act to reduce the performance. Using data from White Lotus River of Hubei Province, China, five methods were used to assimilate radar rainfall data transformed from the classified Z-R relationship, and the postassimilation data were compared with precipitation measured by rain gauges. The five sets of assimilated rainfall data were then used as input to the Xinanjiang model. The effect of precipitation data input error on runoff simulation was analyzed quantitatively by disturbing the input data using the Breeding of Growing Modes method. The results of practical application demonstrated that the statistical weight integration and variational assimilation methods were superior. The corresponding performance in flood hydrograph prediction was also better using the statistical weight integration and variational methods compared to the others. It was found that the errors of radar rainfall data disturbed by the Breeding of Growing Modes had a tendency to accumulate through the hydrological model.

  9. Weather radar performance monitoring using a metallic-grid ground-scatterer

    Science.gov (United States)

    Falconi, Marta Tecla; Montopoli, Mario; Marzano, Frank Silvio; Baldini, Luca

    2017-10-01

    The use of ground return signals is investigated for checks on the calibration of power measurements of a polarimetric C-band radar. To this aim, a peculiar permanent single scatterer (PSS) consisting of a big metallic roof with a periodic mesh grid structure and having a hemisphere-like shape is considered. The latter is positioned in the near-field region of the weather radar and its use, as a reference calibrator, shows fairly good results in terms of reflectivity and differential reflectivity monitoring. In addition, the use of PSS indirectly allows to check for the radar antenna de-pointing which is another issue usually underestimated when dealing with weather radars. Because of the periodic structure of the considered PSS, simulations of its electromagnetic behavior were relatively easy to perform. To this goal, we used an electromagnetic Computer-Aided-Design (CAD) with an ad-hoc numerical implementation of a full-wave solution to model our PSS in terms of reflectivity and differential reflectivity factor. Comparison of model results and experimental measurements are then shown in this work. Our preliminary investigation can pave the way for future studies aiming at characterizing ground-clutter returns in a more accurate way for radar calibration purposes.

  10. Detectability of underground electrical cables junction with a ground penetrating radar: electromagnetic simulation and experimental measurements

    Science.gov (United States)

    Liu, Xiang; serhir, mohammed; kameni, abelin; lambert, marc; pichon, lionel

    2016-04-01

    For a company like Electricity De France (EDF), being able to detect accurately using non-destructive methods the position of the buried junction between two underground cables is a crucial issue. The junction is the linking part where most maintenance operations are carried out. The challenge of this work is to conduct a feasibility study to confirm or deny the relevance of Ground Penetrating Radar (GPR) to detect these buried junctions in their actual environment against clutter. Indeed, the cables are buried in inhomogeneous medium at around 80cm deep. To do this, the study is conducted in a numerical environment. We use the 3D simulation software CST MWS to model a GPR scenario. In this simulation, we place the already optimized bowtie antennas operating in the frequency band [0.5 GHz - 3 GHz] in front of wet soil (dispersive) and dry soil where the underground cable is placed at 80cm deep. We collect the amplitude and phase of the reflected waves in order to detect the contrast provoked by the geometric dimensions variation of the cable [1] (diameter of the cable is 48mm and the diameter of the junction 74mm). The use of an ultra-wideband antenna is necessary to reconcile resolution and penetration of electromagnetic waves in the medium to be characterized. We focus on the performance of the GPR method according to the characteristics of the surrounding medium in which the electric cables are buried, the polarization of the Tx and Rx antennas. The experimental measurement collected in the EDF site will be presented. The measured data are processed using the clutter reduction method based on digital filtering [2]. We aim at showing that using the developed bowtie antennas that the GPR technique is well adapted for the cable junction localization even in cluttered environment. References [1] D. J. Daniels, "Surface-Penetrating Radar", London, IEE 1996. [2] Potin, D.; Duflos, E.; Vanheeghe, P., "Landmines Ground-Penetrating Radar Signal Enhancement by Digital

  11. Consolidated Ground Segment Requirements for a UHF Radar for the ESSAS

    Science.gov (United States)

    Muller, Florent; Vera, Juan

    2009-03-01

    ESA has launched a nine months long study to define the requirements associated to the ground segment of a UHF (300-3000 MHz) radar system. The study has been awarded in open competition to a consortium led by Onera, associated to the Spanish companies Indra and its sub-contractor Deimos. After a phase of consolidation of the requirements, different monostatic and bistatic concepts of radars will be proposed and evaluated. Two concepts will be selected for further design studies. ESA will then select the best one, for detailed design as well as cost and performance evaluation. The aim of this paper is to present the results of the first phase of the study concerning the consolidation of the radar system requirements. The main mission for the system is to be able to build and maintain a catalogue of the objects in low Earth orbit (apogee lower than 2000km) in an autonomous way, for different sizes of objects, depending on the future successive development phases of the project. The final step must give the capability of detecting and tracking 10cm objects, with a possible upgrade to 5 cm objects. A demonstration phase must be defined for 1 m objects. These different steps will be considered during all the phases of the study. Taking this mission and the different steps of the study as a starting point, the first phase will define a set of requirements for the radar system. It was finished at the end of January 2009. First part will describe the constraints derived from the targets and their environment. Orbiting objects have a given distribution in space, and their observability and detectability are based on it. It is also related to the location of the radar system But they are also dependant on the natural propagation phenomenon, especially ionospheric issues, and the characteristics of the objects. Second part will focus on the mission itself. To carry out the mission, objects must be detected and tracked regularly to refresh the associated orbital parameters

  12. Work flow of signal processing data of ground penetrating radar case of rigid pavement measurements

    International Nuclear Information System (INIS)

    Handayani, Gunawan

    2015-01-01

    The signal processing of Ground Penetrating Radar (GPR) requires a certain work flow to obtain good results. Even though the Ground Penetrating Radar data looks similar with seismic reflection data, but the GPR data has particular signatures that the seismic reflection data does not have. This is something to do with coupling between antennae and the ground surface. Because of this, the GPR data should be treated differently from the seismic signal data processing work flow. Even though most of the processing steps still follow the same work flow of seismic reflection data such as: filtering, predictive deconvolution etc. This paper presents the work flow of GPR processing data on rigid pavement measurements. The processing steps start from raw data, de-Wow process, remove DC and continue with the standard process to get rid of noises i.e. filtering process. Some radargram particular features of rigid pavement along with pile foundations are presented

  13. Work flow of signal processing data of ground penetrating radar case of rigid pavement measurements

    Science.gov (United States)

    Handayani, Gunawan

    2015-04-01

    The signal processing of Ground Penetrating Radar (GPR) requires a certain work flow to obtain good results. Even though the Ground Penetrating Radar data looks similar with seismic reflection data, but the GPR data has particular signatures that the seismic reflection data does not have. This is something to do with coupling between antennae and the ground surface. Because of this, the GPR data should be treated differently from the seismic signal data processing work flow. Even though most of the processing steps still follow the same work flow of seismic reflection data such as: filtering, predictive deconvolution etc. This paper presents the work flow of GPR processing data on rigid pavement measurements. The processing steps start from raw data, de-Wow process, remove DC and continue with the standard process to get rid of noises i.e. filtering process. Some radargram particular features of rigid pavement along with pile foundations are presented.

  14. Work flow of signal processing data of ground penetrating radar case of rigid pavement measurements

    Energy Technology Data Exchange (ETDEWEB)

    Handayani, Gunawan [The Earth Physics and Complex Systems Research Group (Jl. Ganesa 10 Bandung Indonesia) gunawanhandayani@gmail.com (Indonesia)

    2015-04-16

    The signal processing of Ground Penetrating Radar (GPR) requires a certain work flow to obtain good results. Even though the Ground Penetrating Radar data looks similar with seismic reflection data, but the GPR data has particular signatures that the seismic reflection data does not have. This is something to do with coupling between antennae and the ground surface. Because of this, the GPR data should be treated differently from the seismic signal data processing work flow. Even though most of the processing steps still follow the same work flow of seismic reflection data such as: filtering, predictive deconvolution etc. This paper presents the work flow of GPR processing data on rigid pavement measurements. The processing steps start from raw data, de-Wow process, remove DC and continue with the standard process to get rid of noises i.e. filtering process. Some radargram particular features of rigid pavement along with pile foundations are presented.

  15. Electromagnetic simulators for Ground Penetrating Radar applications developed in COST Action TU1208

    Science.gov (United States)

    Pajewski, Lara; Giannopoulos, Antonios; Warren, Craig; Antonijevic, Sinisa; Doric, Vicko; Poljak, Dragan

    2017-04-01

    the effectiveness of existing ones. A fast and accurate forward solver can also be used as part of an inverse solver. This contribution aims at presenting two electromagnetic simulators based on the Finite-Difference Time Domain (FDTD) technique and Boundary Element Method (BEM), for Ground Penetrating Radar applications. These tools have been developed by Members of the COST Action TU1208. The first simulator is the new open-source version of the software gprMax (www.GPRadar.eu), which employs Yee's algorithm to solve Maxwell's equations by using the FDTD method and includes advanced features allowing the accurate analysis of realistic scenarios. For example, a library of antennas is available and these can be directly included in the models. Moreover, it is possible to build heterogeneous media using fractals, as well as objects with rough surfaces. Anisotropic media can be defined and this allows materials such as wood and fibre-reinforced concrete to be accurately modelled. Media with arbitrary frequency-dispersive properties can be also defined and this paves the way to the use of gprMax in new areas, such as the modelling of human tissues. Optimisation of parameters based on Taguchi's method can be performed: this feature can be useful to optimise material properties based on experimental data, or to design new antennas. Additionally, a freeware and very useful CAD package was developed, conceived to ease the use of gprMax: such tool assists in the creation, modification and analysis of two-dimensional gprMax models and can also be used to plot results. The second simulator is TWiNS-II: this is free software for the analysis of multiple thin wires in the presence of two media, implementing the Galerkin-Bubnov Indirect BEM; calculations can be undertaken in the frequency or time domain. The time-domain code is focused on the assessment of current distributions along thin wire structures. The configuration that can be analyzed is a set of parallel thin wires

  16. Civil Engineering Applications of Ground Penetrating Radar Recent Advances @ the ELEDIA Research Center

    Science.gov (United States)

    Salucci, Marco; Tenuti, Lorenza; Nardin, Cristina; Oliveri, Giacomo; Viani, Federico; Rocca, Paolo; Massa, Andrea

    2014-05-01

    The application of non-destructive testing and evaluation (NDT/NDE) methodologies in civil engineering has raised a growing interest during the last years because of its potential impact in several different scenarios. As a consequence, Ground Penetrating Radar (GPR) technologies have been widely adopted as an instrument for the inspection of the structural stability of buildings and for the detection of cracks and voids. In this framework, the development and validation of GPR algorithms and methodologies represents one of the most active research areas within the ELEDIA Research Center of the University of Trento. More in detail, great efforts have been devoted towards the development of inversion techniques based on the integration of deterministic and stochastic search algorithms with multi-focusing strategies. These approaches proved to be effective in mitigating the effects of both nonlinearity and ill-posedness of microwave imaging problems, which represent the well-known issues arising in GPR inverse scattering formulations. More in detail, a regularized multi-resolution approach based on the Inexact Newton Method (INM) has been recently applied to subsurface prospecting, showing a remarkable advantage over a single-resolution implementation [1]. Moreover, the use of multi-frequency or frequency-hopping strategies to exploit the information coming from GPR data collected in time domain and transformed into its frequency components has been proposed as well. In this framework, the effectiveness of the multi-resolution multi-frequency techniques has been proven on synthetic data generated with numerical models such as GprMax [2]. The application of inversion algorithms based on Bayesian Compressive Sampling (BCS) [3][4] to GPR is currently under investigation, as well, in order to exploit their capability to provide satisfactory reconstructions in presence of single and multiple sparse scatterers [3][4]. Furthermore, multi-scaling approaches exploiting level-set-based

  17. Interpretation of the distortion of ground-penetrating radar propagated and reflected waves - development of a multi-frequency tomography

    International Nuclear Information System (INIS)

    Hollender, F.

    1999-01-01

    Within the framework of research for waste disposal in deep geological formations, the French agency for nuclear waste management (ANDRA) has to dispose of non-destructive investigation methods to characterize the medium. Ground penetrating radar (GPR) could be used for this purpose in the case of granitic sites. The work presented here deals with this geophysical method. The classical interpretation of GPR data consists in the localization of geological discontinuities by signal amplitude or arrival time analysis. The main objective of our studies is the interpretation of the radar wave distortion (due to propagation and reflection phenomena), not only to localize discontinuities but also to contribute to their identification. Three preliminary studies have been carried out in order to understand on the one hand, the complexity of the electromagnetic phenomena in the geological medium at radar frequency, and on the other hand, the radar equipment constraints. First, the dispersion and the attenuation characterized by a Q variable factor of the GPR waves are shown with the support of dielectric laboratory measurements. A model, which only requires three parameters, is proposed in order to describe this behavior. Second, the radiation patterns of borehole radar antenna are studied. We show that the amplitude and frequency content of the emitted signal are variable versus the emission angle. An analytical method is proposed to study these phenomena. Finally, instrumental drifts of GPR equipment are studied. Emission time, sampling frequency and amplitude fluctuations are described. These elements are taken into account for the processing of propagated signals by tomographic inversion. Medium anisotropy and borehole trajectory errors are inserted in algorithms in order to cancel artifacts which compromised the previous interpretation. A pre-processing method, based on wave separation algorithm, is applied on data in order to increase tomogram resolution. A new

  18. An operational weather radar-based Quantitative Precipitation Estimation and its application in catchment water resources modeling

    DEFF Research Database (Denmark)

    He, Xin; Vejen, Flemming; Stisen, Simon

    2011-01-01

    of precipitation compared with rain-gauge-based methods, thus providing the basis for better water resources assessments. The radar QPE algorithm called ARNE is a distance-dependent areal estimation method that merges radar data with ground surface observations. The method was applied to the Skjern River catchment...... in western Denmark where alternative precipitation estimates were also used as input to an integrated hydrologic model. The hydrologic responses from the model were analyzed by comparing radar- and ground-based precipitation input scenarios. Results showed that radar QPE products are able to generate...... reliable simulations of stream flow and water balance. The potential of using radar-based precipitation was found to be especially high at a smaller scale, where the impact of spatial resolution was evident from the stream discharge results. Also, groundwater recharge was shown to be sensitive...

  19. Hydrogeological characterisation using cross-borehole ground penetration radar and electrical resistivity tomography

    DEFF Research Database (Denmark)

    Zibar, Majken Caroline Looms

    2007-01-01

    was characterized by ~30 m thick unsaturated zone consisting mainly of sands of varying coarseness. Following an instrumentation of 16 boreholes two geophysical methods (cross-borehole ground penetrating radar and electrical resistivity tomography) were applied during natural precipitation and forced infiltration...... properties of the subsurface. On the other hand, volumetric moisture content variations of up to 5% were observed during a 20-day long forced infiltration experiment. The cross-borehole electrical resistance tomography and ground penetrating radar data collected during this experiment were subsequently....... The methods provided estimates of soil moisture content and electrical resistivity variations among 12 m deep boreholes located 5 – 7 m apart. The moisture content change following natural precipitation was observed to be practically negligible, providing minimal information to constrain the dynamic...

  20. Ground penetrating radar for determining volumetric soil water content ; results of comparative measurements at two test sites

    NARCIS (Netherlands)

    Overmeeren, R.A. van; Sariowan, S.V.; Gehrels, J.C.

    1997-01-01

    Ground penetrating radar (GPR) can provide information on the soil water content of the unsaturated zone in sandy deposits via measurements from the surface, and so avoids drilling. Proof of this was found from measurements of radar wave velocities carried out ten times over 13 months at two test

  1. Application of Coupled-Wave Wentzel-Kramers-Brillouin Approximation to Ground Penetrating Radar

    OpenAIRE

    Igor Prokopovich; Alexei Popov; Lara Pajewski; Marian Marciniak

    2017-01-01

    This paper deals with bistatic subsurface probing of a horizontally layered dielectric half-space by means of ultra-wideband electromagnetic waves. In particular, the main objective of this work is to present a new method for the solution of the two-dimensional back-scattering problem arising when a pulsed electromagnetic signal impinges on a non-uniform dielectric half-space; this scenario is of interest for ground penetrating radar (GPR) applications. For the analytical description of the s...

  2. Ground-penetrating radar observations for estimating the vertical displacement of rotational landslides

    OpenAIRE

    C. Lissak; O. Maquaire; J.-P. Malet; F. Lavigne; C. Virmoux; C. Gomez; R. Davidson

    2014-01-01

    The objective of this paper is to demonstrate the applicability of Ground Penetrating Radar (GPR) for monitoring the displacement of slow-moving landslides. GPR data is used to estimate the vertical movement of rotational slides in combination with other surveying techniques. The experimental site is located along the Normandy coast (North East France) here several rotational landslides are continuously affected by a seasonal kinematic pattern (low displacem...

  3. Seismic-reflection and ground penetrating radar for environmental site characterization. 1998 annual progress report

    International Nuclear Information System (INIS)

    Plumb, R.; Steeples, D.W.

    1998-01-01

    the seismic reflection data and the ground-penetrating radar (GPR) data over time. Two factors drive these changes: First, the soil-moisture conditions vary on a seasonal basis at the site. Second, the water table rises and falls on the order of one meter in response to changes in the level of the Arkansas River and in response to the many irrigation wells found nearby. At the test site in the Arkansas River alluvial valley near Great Bend, Kansas, surface material consists of unconsolidated medium- to coarse-grained sand interspersed with clay stringers and lenses deposited by the Arkansas River. A hand-augered test hole 5 meters from the seismic line revealed sand to a depth of about 1.5 meters, where a hard pan was found presumably a clay layer. At the time of the seismic and GPR surveys, the water table was at a depth of 2.1 meters, based on a measurement in a test well located 25 meters from the seismic line. A well drilled about 40 meters away from the seismic line encountered bedrock (a fine- to medium-grained Cretaceous-age sandstone) at a depth of 29 meters.'

  4. Large-scale, high-definition Ground Penetrating Radar prospection in archaeology

    Science.gov (United States)

    Trinks, I.; Kucera, M.; Hinterleitner, A.; Löcker, K.; Nau, E.; Neubauer, W.; Zitz, T.

    2012-04-01

    The future demands on professional archaeological prospection will be its ability to cover large areas in a time and cost efficient manner with very high spatial resolution and accuracy. The objective of the 2010 in Vienna established Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology (LBI ArchPro) in collaboration with its eight European partner organisations is the advancement of state-of-the-art archaeological sciences. The application and specific further development of remote sensing, geophysical prospection and virtual reality applications, as well as of novel integrated interpretation approaches dedicated to non-invasive spatial archaeology combining near-surface prospection methods with advanced computer science is crucial for modern archaeology. Within the institute's research programme different areas for distinct case studies in Austria, Germany, Norway, Sweden and the UK have been selected as basis for the development and testing of new concepts for efficient and universally applicable tools for spatial, non-invasive archaeology. In terms of geophysical prospection the investigation of entire archaeological landscapes for the exploration and protection of Europe's buried cultural heritage requires new measurement devices, which are fast, accurate and precise. Therefore the further development of motorized, multichannel survey systems and advanced navigation solutions is required. The use of motorized measurement devices for archaeological prospection implicates several technological and methodological challenges. Latest multichannel Ground Penetrating Radar (GPR) arrays mounted in front off, or towed behind motorized survey vehicles permit large-scale GPR prospection surveys with unprecedented spatial resolution. In particular the motorized 16 channel 400 MHz MALÅ Imaging Radar Array (MIRA) used by the LBI ArchPro in combination with latest automatic data positioning and navigation solutions permits the reliable high

  5. Efficiency evaluation of ground-penetrating radar by the results of measurement of dielectric properties of soils

    Energy Technology Data Exchange (ETDEWEB)

    Khakiev, Zelimkhan; Kislitsa, Konstantin; Yavna, Victor [Rostov State Transport University, Rostov-on-Don (Russian Federation)

    2012-12-15

    The work considers the depth evaluation of ground penetrating radar (GPR) surveys using the attenuation factor of electromagnetic radiation in a medium. A method of determining the attenuation factor of low-conductive non-magnetic soils is developed based on the results of direct measurements of permittivity and conductivity of soils in the range of typical frequencies of GPR. The method relies on measuring the shift and width of the resonance line after a soil sample is being placed into a tunable cavity resonator. The advantage of this method is the preservation of soil structure during the measurement.

  6. Holocene relative sea level variations at the spit system Feddet (Denmark) resolved by ground-penetrating radar and geomorphological data

    DEFF Research Database (Denmark)

    Hede, Mikkel Ulfeldt; Bendixen, Mette; Clemmensen, Lars B

    Estimates of Holocene sea-level variations have been presented in a range of studies based on different approaches, including interpretation of internal beach ridge characteristics from ground-penetrating radar (GPR) and geomorphological data. We present GPR data and geomorphological observations...... of independent GPR and geomorphologic data collected across the recent and sub-recent beach ridge deposits. The data analyses include coastal topography, internal dips of beach ridge layers, and sea-level measurements. A clear change in characteristic layer dip is observed between beach face and upper shoreface...

  7. Interferometric evidence for the observation of ground backscatter originating behind the CUTLASS coherent HF radars

    Science.gov (United States)

    Milan, S. E.; Jones, T. B.; Robinson, T. R.; Thomas, E. C.; Yeoman, T. K.

    1997-01-01

    Interferometric techniques allow the SuperDARN coherent HF radars to determine the elevation angles of returned backscatter, giving information on the altitude of the scatter volume, in the case of ionospheric backscatter, or the reflection altitude, in the case of ground backscatter. Assumptions have to be made in the determination of elevation angles, including the direction of arrival, or azimuth, of the returned signals, usually taken to be the forward look-direction (north) of the radars, specified by the phasing of the antenna arrays. It is shown that this assumption is not always valid in the case of ground backscatter, and that significant returns can be detected from the backward look-direction of the radars. The response of the interferometer to backscatter from behind the radar is modelled and compared with observations. It is found that ground backscatter from a field-of-view that is the mirror image of the forward-looking field-of-view is a common feature of the observations, and this interpretation successfully explains several anomalies in the received backscatter. Acknowledgements. The authors are grateful to Prof. D. J. Southwood (Imperial College, London), J. C. Samson (University of Alberta, Edmonton), L. J. Lanzerotti (AT&T Bell Laboratories), A. Wolfe (New York City Technical College) and to Dr. M. Vellante (University of LÁquila) for helpful discussions. They also thank Dr. A. Meloni (Istituto Nazionale di Geofisica, Roma) who made available geomagnetic field observations from LÁquila Geomagnetic Observatory. This research activity at LÁquila is supported by MURST (40% and 60% contracts) and by GIFCO/CNR. Topical Editor K.-H. Glaßmeier thanks C. Waters and S. Fujita for their help in evaluating this paper.-> Correspondence to :P. Francia->

  8. Radar Target Classification using Recursive Knowledge-Based Methods

    DEFF Research Database (Denmark)

    Jochumsen, Lars Wurtz

    The topic of this thesis is target classification of radar tracks from a 2D mechanically scanning coastal surveillance radar. The measurements provided by the radar are position data and therefore the classification is mainly based on kinematic data, which is deduced from the position. The target...... been terminated. Therefore, an update of the classification results must be made for each measurement of the target. The data for this work are collected throughout the PhD and are both collected from radars and other sensors such as GPS....

  9. Assimilation of radar-based nowcast into HIRLAM NWP model

    DEFF Research Database (Denmark)

    Jensen, David Getreuer; Petersen, Claus; Rasmussen, Michael R.

    2015-01-01

    The present study introduces a nowcast scheme that assimilates radar extrapolation data (RED) into a nowcasting version of the high resolution limited area model (HIRLAM) numerical weather prediction (NWP) model covering the area of Denmark. The RED are based on the Co-TREC (tracking radar echoes...... by correlation) methodology and are generated from cleaned radar mosaics from the Danish weather radar network. The assimilation technique is a newly developed method that increases model precipitation by increasing low-level convergence and decreasing convergence aloft in order to increase the vertical velocity....... The level of improved predictability relies on the RED quality, which again relies on the type of event....

  10. Beach-ridge architecture constrained by beach topography and Ground-Penetrating Radar, Itilleq (Lakse Bugt), Disko, Greenland – Implications for sea-level reconstructions

    DEFF Research Database (Denmark)

    Emerich Souza, Priscila; Kroon, Aart; Nielsen, Lars

    2018-01-01

    Detailed topographical data and high-resolution ground-penetrating radar (GPR) reflection data are presented from the present-day beach and across successive raised beach-ridges at Itilleq (Disko, West Greenland). In the western part of our study area, the present low-tide level is well-marked by......Detailed topographical data and high-resolution ground-penetrating radar (GPR) reflection data are presented from the present-day beach and across successive raised beach-ridges at Itilleq (Disko, West Greenland). In the western part of our study area, the present low-tide level is well...... beach-ridge GPR profiles. Most of them are located at the boundary between a unit with reflection characteristics representing palaeo foreshore deposits, and a deeper and more complex radar unit characterized by diffractions, which, however, is not penetrated to large depths by the GPR signals. Based...

  11. Mutual information-based LPI optimisation for radar network

    Science.gov (United States)

    Shi, Chenguang; Zhou, Jianjiang; Wang, Fei; Chen, Jun

    2015-07-01

    Radar network can offer significant performance improvement for target detection and information extraction employing spatial diversity. For a fixed number of radars, the achievable mutual information (MI) for estimating the target parameters may extend beyond a predefined threshold with full power transmission. In this paper, an effective low probability of intercept (LPI) optimisation algorithm is presented to improve LPI performance for radar network. Based on radar network system model, we first provide Schleher intercept factor for radar network as an optimisation metric for LPI performance. Then, a novel LPI optimisation algorithm is presented, where for a predefined MI threshold, Schleher intercept factor for radar network is minimised by optimising the transmission power allocation among radars in the network such that the enhanced LPI performance for radar network can be achieved. The genetic algorithm based on nonlinear programming (GA-NP) is employed to solve the resulting nonconvex and nonlinear optimisation problem. Some simulations demonstrate that the proposed algorithm is valuable and effective to improve the LPI performance for radar network.

  12. Evaluation on surface current observing network of high frequency ground wave radars in the Gulf of Thailand

    Science.gov (United States)

    Yin, Xunqiang; Shi, Junqiang; Qiao, Fangli

    2018-05-01

    Due to the high cost of ocean observation system, the scientific design of observation network becomes much important. The current network of the high frequency radar system in the Gulf of Thailand has been studied using a three-dimensional coastal ocean model. At first, the observations from current radars have been assimilated into this coastal model and the forecast results have improved due to the data assimilation. But the results also show that further optimization of the observing network is necessary. And then, a series of experiments were carried out to assess the performance of the existing high frequency ground wave radar surface current observation system. The simulated surface current data in three regions were assimilated sequentially using an efficient ensemble Kalman filter data assimilation scheme. The experimental results showed that the coastal surface current observation system plays a positive role in improving the numerical simulation of the currents. Compared with the control experiment without assimilation, the simulation precision of surface and subsurface current had been improved after assimilated the surface currents observed at current networks. However, the improvement for three observing regions was quite different and current observing network in the Gulf of Thailand is not effective and a further optimization is required. Based on these evaluations, a manual scheme has been designed by discarding the redundant and inefficient locations and adding new stations where the performance after data assimilation is still low. For comparison, an objective scheme based on the idea of data assimilation has been obtained. Results show that all the two schemes of observing network perform better than the original network and optimal scheme-based data assimilation is much superior to the manual scheme that based on the evaluation of original observing network in the Gulf of Thailand. The distributions of the optimal network of radars could be a

  13. Nondestructive Evaluation of Concrete Bridge Decks with Automated Acoustic Scanning System and Ground Penetrating Radar.

    Science.gov (United States)

    Sun, Hongbin; Pashoutani, Sepehr; Zhu, Jinying

    2018-06-16

    Delamanintions and reinforcement corrosion are two common problems in concrete bridge decks. No single nondestructive testing method (NDT) is able to provide comprehensive characterization of these defects. In this work, two NDT methods, acoustic scanning and Ground Penetrating Radar (GPR), were used to image a straight concrete bridge deck and a curved intersection ramp bridge. An acoustic scanning system has been developed for rapid delamination mapping. The system consists of metal-ball excitation sources, air-coupled sensors, and a GPS positioning system. The acoustic scanning results are presented as a two-dimensional image that is based on the energy map in the frequency range of 0.5⁻5 kHz. The GPR scanning results are expressed as the GPR signal attenuation map to characterize concrete deterioration and reinforcement corrosion. Signal processing algorithms for both methods are discussed. Delamination maps from the acoustic scanning are compared with deterioration maps from the GPR scanning on both bridges. The results demonstrate that combining the acoustic and GPR scanning results will provide a complementary and comprehensive evaluation of concrete bridge decks.

  14. Detection of Subsurface Defects in Levees in Correlation to Weather Conditions Utilizing Ground Penetrating Radar

    Science.gov (United States)

    Martinez, I. A.; Eisenmann, D.

    2012-12-01

    Ground Penetrating Radar (GPR) has been used for many years in successful subsurface detection of conductive and non-conductive objects in all types of material including different soils and concrete. Typical defect detection is based on subjective examination of processed scans using data collection and analysis software to acquire and analyze the data, often requiring a developed expertise or an awareness of how a GPR works while collecting data. Processing programs, such as GSSI's RADAN analysis software are then used to validate the collected information. Iowa State University's Center for Nondestructive Evaluation (CNDE) has built a test site, resembling a typical levee used near rivers, which contains known sub-surface targets of varying size, depth, and conductivity. Scientist at CNDE have developed software with the enhanced capabilities, to decipher a hyperbola's magnitude and amplitude for GPR signal processing. With this enhanced capability, the signal processing and defect detection capabilities for GPR have the potential to be greatly enhanced. This study will examine the effects of test parameters, antenna frequency (400MHz), data manipulation methods (which include data filters and restricting the range of depth in which the chosen antenna's signal can reach), and real-world conditions using this test site (such as varying weather conditions) , with the goal of improving GPR tests sensitivity for differing soil conditions.

  15. Design and validation of inert homemade explosive simulants for ground penetrating radar

    Science.gov (United States)

    VanderGaast, Brian W.; McFee, John E.; Russell, Kevin L.; Faust, Anthony A.

    2015-05-01

    The Canadian Armed Forces (CAF) identified a requirement for inert simulants to act as improvised, or homemade, explosives (IEs) when training on, or evaluating, ground penetrating radar (GPR) systems commonly used in the detection of buried landmines and improvised explosive devices (IEDs). In response, Defence R and D Canada (DRDC) initiated a project to develop IE simulant formulations using commonly available inert materials. These simulants are intended to approximate the expected GPR response of common ammonium nitrate-based IEs, in particular ammonium nitrate/fuel oil (ANFO) and ammonium nitrate/aluminum (ANAl). The complex permittivity over the range of electromagnetic frequencies relevant to standard GPR systems was measured for bulk quantities of these three IEs that had been fabricated at DRDC Suffield Research Centre. Following these measurements, published literature was examined to find benign materials with both a similar complex permittivity, as well as other physical properties deemed desirable - such as low-toxicity, thermal stability, and commercial availability - in order to select candidates for subsequent simulant formulation. Suitable simulant formulations were identified for ANFO, with resulting complex permittivities measured to be within acceptable limits of target values. These IE formulations will now undergo end-user trials with CAF operators in order to confirm their utility. Investigations into ANAl simulants continues. This progress report outlines the development program, simulant design, and current validation results.

  16. The soil classification and the subsurface carbon stock estimation with a ground-penetrating radar

    International Nuclear Information System (INIS)

    Onishi, K.; Rokugawa, S.; Kato, Y.

    2002-01-01

    One of the serious problems of the Kyoto Protocol is that we have no effective method to estimate the carbon stock of the subsurface. To solve this problem, we propose the application of ground-penetrating radar (GPR) to the subsurface soil survey. As a result, it is shown that GPR can detect the soil horizons, stones and roots. The fluctuations of the soil horizons in the forest are cleanly indicated as the reflection pattern of the microwaves. Considering the fact that the physical, chemical, and biological characteristics of each soil layer is almost unique, GPR results can be used to estimate the carbon stock in soil by combining with the vertical soil sample survey at one site. Then as a trial, we demonstrate to estimate the carbon content fixed in soil layers based on the soil samples and GPR survey data. we also compare this result with the carbon stock for the flat horizon case. The advantages of GPR usage for this object are not only the reduction of uncertainty and the cost, but also the environmental friendliness of survey manner. Finally, we summarize the adaptabilities of various antennas having different predominant frequencies for the shallow subsurface zone. (author)

  17. Modelling of ground penetrating radar data in stratified media using the reflectivity technique

    International Nuclear Information System (INIS)

    Sena, Armando R; Sen, Mrinal K; Stoffa, Paul L

    2008-01-01

    Horizontally layered media are often encountered in shallow exploration geophysics. Ground penetrating radar (GPR) data in these environments can be modelled by techniques that are more efficient than finite difference (FD) or finite element (FE) schemes because the lateral homogeneity of the media allows us to reduce the dependence on the horizontal spatial variables through Fourier transforms on these coordinates. We adapt and implement the invariant embedding or reflectivity technique used to model elastic waves in layered media to model GPR data. The results obtained with the reflectivity and FDTD modelling techniques are in excellent agreement and the effects of the air–soil interface on the radiation pattern are correctly taken into account by the reflectivity technique. Comparison with real wide-angle GPR data shows that the reflectivity technique can satisfactorily reproduce the real GPR data. These results and the computationally efficient characteristics of the reflectivity technique (compared to FD or FE) demonstrate its usefulness in interpretation and possible model-based inversion schemes of GPR data in stratified media

  18. Surveying glacier bedrock topography with a helicopter-borne dual-polarization ground-penetrating radar system

    Science.gov (United States)

    Langhammer, L.; Rabenstein, L.; Schmid, L.; Bauder, A.; Schaer, P.; Maurer, H.

    2017-12-01

    Glacier mass estimations are crucial for future run-off projections in the Swiss Alps. Traditionally, ice thickness modeling approaches and ground-based radar transects have been the tools of choice for estimating glacier volume in high mountain areas, but these methods either contain high uncertainties or are logistically expensive and offer mostly only sparse subsurface information. We have developed a helicopter-borne dual-polarization ground-penetrating radar (GPR) system, which enhances operational feasibility in rough, high-elevation terrain and increases the data output per acquisition campaign significantly. Our system employs a prototype pulseEKKO device with two broadside 25-MHz antenna pairs fixed to a helicopter-towed wooden frame. Additionally attached to the system are a laser altimeter for measuring the flight height above ground, three GPS receivers for accurate positioning and a GoPro camera for obtaining visual images of the surface. Previous investigations have shown the significant impact of the antenna dipole orientation on the detectability of the bedrock reflection. For optimal results, the dipoles of the GPR should be aligned parallel to the strike direction of the surrounding mountain walls. In areas with a generally unknown bedrock topography, such as saddle areas or diverging zones, a dual-polarization system is particularly useful. This could be demonstrated with helicopter-borne GPR profiles acquired on more than 25 glaciers in the Swiss Alps. We observed significant differences in ice-bedrock interface visibility depending on the orientation of the antennas.

  19. Fpga based L-band pulse doppler radar design and implementation

    Science.gov (United States)

    Savci, Kubilay

    As its name implies RADAR (Radio Detection and Ranging) is an electromagnetic sensor used for detection and locating targets from their return signals. Radar systems propagate electromagnetic energy, from the antenna which is in part intercepted by an object. Objects reradiate a portion of energy which is captured by the radar receiver. The received signal is then processed for information extraction. Radar systems are widely used for surveillance, air security, navigation, weather hazard detection, as well as remote sensing applications. In this work, an FPGA based L-band Pulse Doppler radar prototype, which is used for target detection, localization and velocity calculation has been built and a general-purpose Pulse Doppler radar processor has been developed. This radar is a ground based stationary monopulse radar, which transmits a short pulse with a certain pulse repetition frequency (PRF). Return signals from the target are processed and information about their location and velocity is extracted. Discrete components are used for the transmitter and receiver chain. The hardware solution is based on Xilinx Virtex-6 ML605 FPGA board, responsible for the control of the radar system and the digital signal processing of the received signal, which involves Constant False Alarm Rate (CFAR) detection and Pulse Doppler processing. The algorithm is implemented in MATLAB/SIMULINK using the Xilinx System Generator for DSP tool. The field programmable gate arrays (FPGA) implementation of the radar system provides the flexibility of changing parameters such as the PRF and pulse length therefore it can be used with different radar configurations as well. A VHDL design has been developed for 1Gbit Ethernet connection to transfer digitized return signal and detection results to PC. An A-Scope software has been developed with C# programming language to display time domain radar signals and detection results on PC. Data are processed both in FPGA chip and on PC. FPGA uses fixed

  20. Combining ground penetrating radar and electromagnetic induction for industrial site characterization

    Science.gov (United States)

    Van De Vijver, Ellen; Van Meirvenne, Marc; Saey, Timothy; De Smedt, Philippe; Delefortrie, Samuël; Seuntjens, Piet

    2014-05-01

    Industrial sites pose specific challenges to the conventional way of characterizing soil and groundwater properties through borehole drilling and well monitoring. The subsurface of old industrial sites typically exhibits a large heterogeneity resulting from various anthropogenic interventions, such as the dumping of construction and demolition debris and industrial waste. Also larger buried structures such as foundations, utility infrastructure and underground storage tanks are frequently present. Spills and leaks from industrial activities and leaching of buried waste may have caused additional soil and groundwater contamination. Trying to characterize such a spatially heterogeneous medium with a limited number of localized observations is often problematic. The deployment of mobile proximal soil sensors may be a useful tool to fill up the gaps in between the conventional observations, as these enable measuring soil properties in a non-destructive way. However, because the output of most soil sensors is affected by more than one soil property, the application of only one sensor is generally insufficient to discriminate between all contributing factors. To test a multi-sensor approach, we selected a study area which was part of a former manufactured gas plant site located in one of the seaport areas of Belgium. It has a surface area of 3400 m² and was the location of a phosphate production unit that was demolished at the end of the 1980s. Considering the long and complex history of the site we expected to find a typical "industrial" soil. Furthermore, the studied area was located between buildings of the present industry, entailing additional practical challenges such as the presence of active utilities and aboveground obstacles. The area was surveyed using two proximal soil sensors based on two different geophysical methods: ground penetrating radar (GPR), to image contrasts in dielectric permittivity, and electromagnetic induction (EMI), to measure the apparent

  1. Pulse Doppler radar

    CERN Document Server

    Alabaster, Clive

    2012-01-01

    This book is a practitioner's guide to all aspects of pulse Doppler radar. It concentrates on airborne military radar systems since they are the most used, most complex, and most interesting of the pulse Doppler radars; however, ground-based and non-military systems are also included. It covers the fundamental science, signal processing, hardware issues, systems design and case studies of typical systems. It will be a useful resource for engineers of all types (hardware, software and systems), academics, post-graduate students, scientists in radar and radar electronic warfare sectors and milit

  2. Single Frequency Network Based Distributed Passive Radar Technology

    Directory of Open Access Journals (Sweden)

    Wan Xian-rong

    2015-01-01

    Full Text Available The research and application of passive radar are heading from single transmitter-receiver pair to multiple transmitter-receiver pairs. As an important class of the illuminators of opportunity, most of modern digital broadcasting and television systems work on Single Frequency Network (SFN, which intrinsically determines that the passive radar based on such illuminators must be distributed and networked. In consideration of the remarkable working and processing mode of passive radar under SFN configuration, this paper proposes the concept of SFN-based Distributed Passive Radar (SDPR. The main characteristics and key problems of SDPR are first described. Then several potential solutions are discussed for part of the key technologies. The feasibility of SDPR is demonstrated by preliminary experimental results. Finally, the concept of four network convergence that includes the broadcast based passive radar network is conceived, and its application prospects are discussed.

  3. Multi-function radar emitter identification based on stochastic syntax-directed translation schema

    OpenAIRE

    Liu, Haijun; Yu, Hongqi; Sun, Zhaolin; Diao, Jietao

    2014-01-01

    To cope with the problem of emitter identification caused by the radar words’ uncertainty of measured multi-function radar emitters, this paper proposes a new identification method based on stochastic syntax-directed translation schema (SSDTS). This method, which is deduced from the syntactic modeling of multi-function radars, considers the probabilities of radar phrases appearance in different radar modes as well as the probabilities of radar word errors occurrence in different radar phrases...

  4. Performance limits for exo-clutter Ground Moving Target Indicator (GMTI) radar.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2010-09-01

    The performance of a Ground Moving Target Indicator (GMTI) radar system depends on a variety of factors, many which are interdependent in some manner. It is often difficult to 'get your arms around' the problem of ascertaining achievable performance limits, and yet those limits exist and are dictated by physics. This report identifies and explores those limits, and how they depend on hardware system parameters and environmental conditions. Ultimately, this leads to a characterization of parameters that offer optimum performance for the overall GMTI radar system. While the information herein is not new to the literature, its collection into a single report hopes to offer some value in reducing the 'seek time'.

  5. Characterization of concrete properties from dielectric properties using ground penetrating radar

    International Nuclear Information System (INIS)

    Lai, W.L.; Kou, S.C.; Tsang, W.F.; Poon, C.S.

    2009-01-01

    This paper presents the experimental results of a study of the relationships between light-weight (LWAC) and normal aggregate concrete (NAC) properties, as well as radar wave properties that are derived by using ground penetrating radar (GPR). The former (LWAC) refers to compressive strength, apparent porosity and saturated density, while the latter (NAC) refers to real part of dielectric permittivity (ε' or real permittivity) and wave energy level (E). Throughout the test period of the newly cast concrete cured for 90 days, the above mentioned material properties gradually changed which can be attributed to the effects of cement hydration, different types of aggregates and initial water to binder ratios. A number of plots describing various properties of concrete such as dielectric, strength and porosity perspectives were established. From these plots, we compare the characteristics of how much and how fast free water was turned to absorbed water in LWAC and NAC. The underlying mechanisms and a mechanistic model are then developed.

  6. The Use of Ground Penetrating Radar to extend the Results of Archaeological Excavation

    Science.gov (United States)

    Utsi, E.

    2009-04-01

    The condition of the Romano-British archaeological site in Wortley, Gloucestershire, UK is typical of sites of the period in that it has been heavily robbed out since it first fell into disuse. Building materials taken from the site have been re-used over the centuries to construct other local buildings. This makes both preservation of the extant remains and interpretation of the excavation problematic. Following the accidental discovery of the site in the 1980s, a programme of excavation was set in place. This excavation was run as a practical archaeological training school and, as a result, a wide range of archaeological and geophysical techniques were applied to the site. This included the introduction of Ground Penetrating Radar (GPR). The preliminary results of the first GPR used on site were not entirely satisfactory which led to the development of a new radar in the early 1990s, specifically developed for use on archaeological sites. The excavation and GPR results were published in a series of excavation reports [1] [2]. It was not possible to excavate fully for two reasons. Firstly the site crossed present day ownership boundaries and secondly the ownership of the excavation area changed. At this point the excavation was summarily terminated. In 2007, permission was given by the owner of an adjacent property to carry out a GPR survey over their land in order to derive additional information, if possible. An area survey was carried out in May 2007 with reduced transect spacing [3]. The radar data showed similar patterning to that of the original investigation i.e. substantial remains which had been subject to a high degree of post-occupational attrition. Time slices from the radar survey were matched to the principal excavation plans. It proved possible to deduce the full extent of certain partially excavated features, notably the courtyard and bath house. It was also possible to demonstrate that one part of the adjacent property did not contain similar

  7. Ground penetrating radar results at the Box Canyon Site - 1996 survey as part of infiltration test

    International Nuclear Information System (INIS)

    Peterson, J.E. Jr.; Williams, K.H.

    1997-08-01

    This data report presents a discussion of the borehole radar tomography experiment conducted at Box Canyon, Idaho. Discussion concentrates on the survey methodology, data acquisition procedures, and the resulting tomographic images and interpretations. The entire geophysics field effort for FY96 centered around the collection of the borehole radar data within the inclined boreholes R1, R2, R3, and R4 before, during, and after the ponded infiltration experiment. The well pairs R1-R2, R2-R4, and R3-R4 comprised the bulk of the field survey; however, additional data were collected between vertical boreholes within and around the infiltration basin. The intent of the inclined boreholes was to allow access beneath the infiltration basin and to enhance the ability of the radar method to image both vertical and horizontal features where flow may dominate. This data report will concentrate on the inclined borehole data and the resulting tomograms. The borehole radar method is one in which modified ground penetrating radar antennas are lowered into boreholes and high frequency electromagnetic signals are transmitted through subsurface material to a receiving antenna. The transmitted signals may be represented as multiple raypaths crossing through the zone of interest. If sufficient raypaths are recorded, a tomographic image may be obtained through computer processing. The data normally recorded are signal amplitude versus time. The information extracted from such data includes the following: (a) the transit time which depends on the wave velocity, (b) the amplitude which depends on the wave attenuation, the dispersion which indicates a change in velocity and attenuation with frequency

  8. High-resolution, real-time mapping of surface soil moisture at the field scale using ground penetrating radar

    Science.gov (United States)

    Lambot, S.; Minet, J.; Slob, E.; Vereecken, H.; Vanclooster, M.

    2008-12-01

    Measuring soil surface water content is essential in hydrology and agriculture as this variable controls important key processes of the hydrological cycle such as infiltration, runoff, evaporation, and energy exchanges between the earth and the atmosphere. We present a ground-penetrating radar (GPR) method for automated, high-resolution, real-time mapping of soil surface dielectric permittivity and correlated water content at the field scale. Field scale characterization and monitoring is not only necessary for field scale management applications, but also for unravelling upscaling issues in hydrology and bridging the scale gap between local measurements and remote sensing. In particular, such methods are necessary to validate and improve remote sensing data products. The radar system consists of a vector network analyzer combined with an off-ground, ultra-wideband monostatic horn antenna, thereby setting up a continuous-wave steeped-frequency GPR. Radar signal analysis is based on three-dimensional electromagnetic inverse modelling. The forward model accounts for all antenna effects, antenna-soil interactions, and wave propagation in three-dimensional multilayered media. A fast procedure was developed to evaluate the involved Green's function, resulting from a singular, complex integral. Radar data inversion is focused on the surface reflection in the time domain. The method presents considerable advantages compared to the current surface characterization methods using GPR, namely, the ground wave and common reflection methods. Theoretical analyses were performed, dealing with the effects of electric conductivity on the surface reflection when non-negligible, and on near-surface layering, which may lead to unrealistic values for the surface dielectric permittivity if not properly accounted for. Inversion strategies are proposed. In particular the combination of GPR with electromagnetic induction data appears to be promising to deal with highly conductive soils

  9. Ground-based photo monitoring

    Science.gov (United States)

    Frederick C. Hall

    2000-01-01

    Ground-based photo monitoring is repeat photography using ground-based cameras to document change in vegetation or soil. Assume those installing the photo location will not be the ones re-photographing it. This requires a protocol that includes: (1) a map to locate the monitoring area, (2) another map diagramming the photographic layout, (3) type and make of film such...

  10. Three dimensional numerical modeling for ground penetrating radar using finite difference time domain (FDTD) method; Jikan ryoiki yugen sabunho ni yoru chika radar no sanjigen suchi modeling

    Energy Technology Data Exchange (ETDEWEB)

    Sanada, Y; Ashida, Y; Sassa, K [Kyoto University, Kyoto (Japan)

    1996-10-01

    3-D numerical modeling by FDTD method was studied for ground penetrating radar. Radar radiates electromagnetic wave, and determines the existence and distance of objects by reflection wave. Ground penetrating radar uses the above functions for underground surveys, however, its resolution and velocity analysis accuracy are problems. In particular, propagation characteristics of electromagnetic wave in media such as heterogeneous and anisotropic soil and rock are essential. The behavior of electromagnetic wave in the ground could be precisely reproduced by 3-D numerical modeling using FDTD method. FDTD method makes precise analysis in time domain and electric and magnetic fields possible by sequentially calculating the difference equation of Maxwell`s equation. Because of the high calculation efficiency of FDTD method, more precise complicated analysis can be expected by using the latest advanced computers. The numerical model and calculation example are illustrated for surface type electromagnetic pulse ground penetrating radar assuming the survey of steel pipes of 1m deep. 4 refs., 3 figs., 1 tab.

  11. Target Detection Based on EBPSK Satellite Passive Radar

    Directory of Open Access Journals (Sweden)

    Lu Zeyuan

    2015-05-01

    Full Text Available Passive radar is a topic anti stealth technology with simple structure, and low cost. Radiation source model, signal transmission model, and target detection are the key points of passive radar technology research. The paper analyzes the characteristics of EBPSK signal modulation and target detection method aspect of spaceborne radiant source. By comparison with other satellite navigation and positioning system, the characteristics of EBPSK satellite passive radar system are analyzed. It is proved that the maximum detection range of EBPSK satellite signal can satisfy the needs of the proposed model. In the passive radar model, sparse representation is used to achieve high resolution DOA detection. The comparison with the real target track by simulation demonstrates that effective detection of airborne target using EBPSK satellite passive radar system based on sparse representation is efficient.

  12. Wideband Cavity Backed Spiral Antenna for Stepped Frequency Ground Penetrating Radar

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne; Lenler-Eriksen, Hans-Rudolph

    2005-01-01

    A 1.7 turn cavity backed coplanar waveguide to coplanar strip-fed logarithmic uniplanar spiral antenna is presented and compared to a 1.5 turn spiral antenna. The 1.7 turn spiral antenna has a wide beamwidth, are circular polarised and has a bandwidth with a return loss better than 6 dB in the fr......B in the frequency band from 0.25 GHz to 4.5 GHz (18:1). The antenna is useful for Ground Penetrating Radar (GPR)....

  13. GPR - Ground penetration radar u prospekciji ležišta arhitektonskog kamena

    OpenAIRE

    Rukavina, Tihomir

    2010-01-01

    Prikazuju se osnove geofizičke metode GPR (Ground Penetratig Radar) i neke specifičnosti pri prospekciji ležišta arhitektonskog kamena. Uređajem je moguće uočiti diskontinuitete i neke druge geološke i geotehničke karakteristike ležišta koji bitno pridonose ekonomskim parametrima eksploatacije. Bitna odlika metode GPR-a je direktno detektiranje položaja i smjera pružanja diskontinuiteta, zona anizotropne ili erodirane građe stijenske mase kao i prisustvo kaverni i drugih ...

  14. Ground-penetrating radar in characterizing and monitoring waste-burial sites

    International Nuclear Information System (INIS)

    Sandness, G.A.; Kimball, C.S.

    1982-02-01

    Potential environmental hazards are associated with buried chemical and nuclear wastes because of the possibilities of inadvertent excavation or migration of toxic chemicals or radionuclides into groundwater or surface water bodies. Concern is often related to the fact that many existing waste burial sites have been found to be inadequately designed and/or poorly documented. New technology and innovative applications of current technology are needed to locate, characterize, and monitor the wastes contained in such sites. The work described in this paper is focused on the use of ground-penetrating radar (GPR) for those purposes

  15. High-resolution mapping, modeling, and evolution of subsurface geomorphology using ground-penetrating radar techniques

    Digital Repository Service at National Institute of Oceanography (India)

    Loveson, V.J.; Gujar, A.R.

    subsurface. It has been useful to decipher shallow geomorphic structures having various options to use different antennas for different depth penetration (0-30 m) with higher resolution.   7.2 Principles of GPR  Ground Penetrating Radar (GPR) was invented... about 90m. Flat and plain land is being used, at present, for agriculture (paddy cultivation) practice. Sand dunes are low lying and highly reworked due to social forestry plantation (acacia) activities. 13    7.8.6 Paleo­Lagoon  GPR data shows two...

  16. Pengolahan data Ground Penetrating Radar (GPR dengan menggunakan software MATGPR R-3.5

    Directory of Open Access Journals (Sweden)

    Elfarabi Amien

    2017-03-01

    Full Text Available Alat Ground Penetration Radar (GPR memancarkan sinyal gelombang elektromagnetik yang dipancarkan kedalam bumi kemudian gelombang elektromagnetik di tangkap saat sudah sampai permukaan bumi. Alat GPR ini dapat memetakan kondisi bawah permukaan yang dilewatinya, selain itu alat ini sangat sensitif terhadap benda-benda yang memiliki komponen atau muatan listrik dan magnet yang besar. Benda-benda tersebut dapat dikatakan sebagai sumber noise. Pengaruh noise ini akan mempengaruhi pada hasil yang keluarkan, oleh karena itu diperlukan pengolahan data untuk menfilter noise tersebut agar dapat menghasilkan hasil yang baik dan tidak menimbulkan kebingungan pada saat proses interpretasi data.

  17. Through the looking glass: Applications of ground-penetrating radar in archaeology

    Science.gov (United States)

    Stamos, Antonia

    The focus of this dissertation is to present the results of four years' worth of geophysical surveying at four major archaeological sites in Greece and the benefits to the archaeological community. The ground penetrating radar offers an inexpensive, non-destructive solution to the problem of deciding how much of a site is worth excavating and which areas would yield the most promising results. An introduction to the ground penetrating radar, or GPR, the equipment necessary to conduct a geophysical survey in the field, and the methods of data collection and subsequent data processing are all addressed. The benefits to the archeological community are many, and future excavations will incorporate such an important tool for a greater understanding of the site. The history of GPR work in the archaeological field has grown at an astounding rate from its beginnings as a simple tool for petroleum and mining services in the beginning of the twentieth century. By mid-century, the GPR was first applied to archaeological sites rather than its common use by utility companies in locating pipes, cables, tunnels, and shafts. Although the preliminary surveys were little more than a search to locate buried walls, the success of these initial surveys paved the ground for future surveys at other archaeological sites, many testing the radar's efficacy with a myriad of soil conditions and properties. The four sites in which geophysical surveys with a ground penetrating radar were conducted are Azorias on the island of Crete, Kolonna on the island of Aegina, Mochlos Island and Coastal Mochlos on the island of Crete, and Mycenae in the Peloponnese on mainland Greece. These case studies are first presented in terms of their geographical location, their mythology and etymology, where applicable, along with a brief history of excavation and occupation of the site. Additional survey methods were used at Mycenae, including aerial photography and ERDAS Imagine, a silo locating program now

  18. Three Decades of Volume Change of a Small Greenlandic Glacier Using Ground Penetrating Radar, Structure from Motion, and Aerial Photogrammetry

    DEFF Research Database (Denmark)

    Marcer, M.; Stentoft, Peter Alexander; Bjerre, Elisa

    2017-01-01

    of ice, corresponding to roughly a quarter of its 1985 volume (148.6 ± 47.6 10 m) and a thinning rate of 0.60 ± 0.11 m a. The computations are challenged by a relatively large fraction of the 1985 DEM (∼50% of the glacier surface) being deemed unreliable owing to low contrast (snow cover) in the 1985......Glaciers in the Arctic are losing mass at an increasing rate. Here we use surface topography derived from Structure from Motion (SfM) and ice volume from ground penetrating radar (GPR) to describe the 2014 state of Aqqutikitsoq glacier (2.85 km) on Greenland's west coast. A photogrammetrically...... derived 1985 digital elevation model (DEM) was subtracted from a 2014 DEM obtained using land-based SfM to calculate geodetic glacier mass balance. Furthermore, a detailed 2014 ground penetrating radar survey was performed to assess ice volume. From 1985 to 2014, the glacier has lost 49.8 ± 9.4 10 m...

  19. Simulation for ground penetrating radar (GPR) study of the subsurface structure of the Moon

    Science.gov (United States)

    Fa, Wenzhe

    2013-12-01

    Ground penetrating radar (GPR) is currently within the scope of China's Chang-E 3 lunar mission, to study the shallow subsurface of the Moon. In this study, key factors that could affect a lunar GPR performance, such as frequency, range resolution, and antenna directivity, are discussed firstly. Geometrical optics and ray tracing techniques are used to model GPR echoes, considering the transmission, attenuation, reflection, geometrical spreading of radar waves, and the antenna directivity. The influence on A-scope GPR echoes and on the simulated radargrams for the Sinus Iridum region by surface and subsurface roughness, dielectric loss of the lunar regolith, radar frequency and bandwidth, and the distance between the transmit and receive antennas are discussed. Finally, potential scientific return about lunar subsurface properties from GPR echoes is also discussed. Simulation results suggest that subsurface structure from several to hundreds of meters can be studied from GPR echoes at P and VHF bands, and information about dielectric permittivity and thickness of subsurface layers can be estimated from GPR echoes in combination with regolith composition data.

  20. Performance of ground-penetrating radar on granitic regoliths with different mineral composition

    Science.gov (United States)

    Breiner, J.M.; Doolittle, James A.; Horton, Radley M.; Graham, R.C.

    2011-01-01

    Although ground-penetrating radar (GPR) is extensively used to characterize the regolith, few studies have addressed the effects of chemical and mineralogical compositions of soils and bedrock on its performance. This investigation evaluated the performance of GPR on two different granitic regoliths of somewhat different mineralogical composition in the San Jacinto Mountains of southern California. Radar records collected at a site where soils are Alfisols were more depth restricted than the radar record obtained at a site where soils are Entisols. Although the Alfisols contain an argillic horizon, and the Entisols have no such horizon of clay accumulation, the main impact on GPR effectiveness is related to mineralogy. The bedrock at the Alfisol site, which contains more mafic minerals (5% hornblende and 20% biotite), is more attenuating to GPR than the bedrock at the Entisol site, where mafic mineral content is less (<1% hornblende and 10% biotite). Thus, a relatively minor variation in bedrock mineralogy, specifically the increased biotite content, severely restricts the performance of GPR. Copyright ?? 2011 by Lippincott Williams & Wilkins.

  1. Subsurface characterization by the ground penetrating radar WISDOM/ExoMars 2020

    Science.gov (United States)

    Hervé, Y.; Ciarletti, V.; Le Gall, A. A.; Oudart, N.; Loizeau, D.; Guiffaut, C.; Dorizon, S.

    2017-12-01

    The main objective of the ExoMars 2020 mission is to search for signs of past and/or present life on Mars. Toward this goal, a rover was designed to investigate the shallow subsurface which is the most likely place where signs of life may be preserved, beneath the hostile surface of Mars. The rover of the ExoMars 2020 mission has on board a polarimetric ground penetrating radar called WISDOM (Water Ice Subsurface Deposits Observation on Mars). Thanks to its large frequency bandwidth of 2.5 GHz, WISDOM is able to probe down to a depth of approximately 3 m on sedimentary rock with a vertical resolution of a few centimeters.The main scientific objectives of WISDOM are to characterize the shallow subsurface of Mars, to help understand the local geological context and to identify the most promising location for drilling. The WISDOM team is currently working on the preparation of the scientific return of the ExoMars 2020 mission. In particular, tools are developed to interpret WISDOM experimental data and, more specifically, to extract information from the radar signatures of expected buried reflectors. Insights into the composition of the ground (through the retrieval of its permittivity) and the geological context of the site can be inferred from the radar signature of buried rocks since the shape and the density of rocks in the subsurface is related to the geological processes that have shaped and placed them there (impact, fluvial processes, volcanism). This paper presents results obtained by automatic detection of structures of interest on a radargram, especially radar signature of buried rocks. The algorithm we developed uses a neural network to identify the position of buried rocks/blocs and then a Hough transform to characterize each signature and to estimate the local permittivity of the medium. Firstly, we will test the performances of the algorithm on simulated data constructed with a 3D FDTD code. This code allows us to simulate radar operation in realistic

  2. Target scattering characteristics for OAM-based radar

    Directory of Open Access Journals (Sweden)

    Kang Liu

    2018-02-01

    Full Text Available The target scattering characteristics are crucial for radar systems. However, there is very little study conducted for the recently developed orbital angular momentum (OAM based radar system. To illustrate the role of OAM-based radar cross section (ORCS, conventional radar equation is modified by taking characteristics of the OAM waves into account. Subsequently, the ORCS is defined in analogy to classical radar cross section (RCS. The unique features of the incident OAM-carrying field are analyzed. The scattered field is derived, and the analytical expressions of ORCSs for metal plate and cylinder targets are obtained. Furthermore, the ORCS and RCS are compared to illustrate the influences of OAM mode number, target size and signal frequency on the ORCS. Analytical studies demonstrate that the mirror-reflection phenomenon disappears and peak values of ORCS are in the non-specular direction. Finally, the ORCS features are summarized to show its advantages in radar target detection. This work can provide theoretical guidance to the design of OAM-based radar as well as the target detection and identification applications.

  3. Target scattering characteristics for OAM-based radar

    Science.gov (United States)

    Liu, Kang; Gao, Yue; Li, Xiang; Cheng, Yongqiang

    2018-02-01

    The target scattering characteristics are crucial for radar systems. However, there is very little study conducted for the recently developed orbital angular momentum (OAM) based radar system. To illustrate the role of OAM-based radar cross section (ORCS), conventional radar equation is modified by taking characteristics of the OAM waves into account. Subsequently, the ORCS is defined in analogy to classical radar cross section (RCS). The unique features of the incident OAM-carrying field are analyzed. The scattered field is derived, and the analytical expressions of ORCSs for metal plate and cylinder targets are obtained. Furthermore, the ORCS and RCS are compared to illustrate the influences of OAM mode number, target size and signal frequency on the ORCS. Analytical studies demonstrate that the mirror-reflection phenomenon disappears and peak values of ORCS are in the non-specular direction. Finally, the ORCS features are summarized to show its advantages in radar target detection. This work can provide theoretical guidance to the design of OAM-based radar as well as the target detection and identification applications.

  4. Unlocking annual firn layer water equivalents from ground-penetrating radar data on an Alpine glacier

    Directory of Open Access Journals (Sweden)

    L. Sold

    2015-05-01

    Full Text Available The spatial representation of accumulation measurements is a major limitation for current glacier mass balance monitoring approaches. Here, we present a method for estimating annual accumulation rates on a temperate Alpine glacier based on the interpretation of internal reflection horizons (IRHs in helicopter-borne ground-penetrating radar (GPR data. For each individual GPR measurement, the signal travel time is combined with a simple model for firn densification and refreezing of meltwater. The model is calibrated at locations where GPR repeat measurements are available in two subsequent years and the densification can be tracked over time. Two 10.5 m long firn cores provide a reference for the density and chronology of firn layers. Thereby, IRHs correspond to density maxima, but not exclusively to former summer glacier surfaces. Along GPR profile sections from across the accumulation area we obtain the water equivalent (w.e. of several annual firn layers. Because deeper IRHs could be tracked over shorter distances, the total length of analysed profile sections varies from 7.3 km for the uppermost accumulation layer (2011 to 0.1 km for the deepest (i.e. oldest layer (2006. According to model results, refreezing accounts for 10% of the density increase over time and depth, and for 2% of the water equivalent. The strongest limitation to our method is the dependence on layer chronology assumptions. We show that GPR can be used not only to complement existing mass balance monitoring programmes on temperate glaciers but also to retrospectively extend newly initiated time series.

  5. A blind test of nondestructive underground void detection by ground penetrating radar (GPR)

    Science.gov (United States)

    Lai, Wallace W. L.; Chang, Ray K. W.; Sham, Janet F. C.

    2018-02-01

    Blind test/experiment is widely adopted in various scientific disciplines like medicine drug testing/clinical trials/psychology, but not popular in nondestructive testing and evaluation (NDTE) nor near-surface geophysics (NSG). This paper introduces a blind test of nondestructive underground void detection in highway/pavement using ground penetrating radar (GPR). Purpose of which is to help the Highways Department (HyD) of the Hong Kong Government to evaluate the feasibility of large-scale and nationwide application, and examine the ability of appropriate service providers to carry out such works. In the past failure case of such NDTE/NSG based on lowest bid price, it is not easy to know which part(s) in SWIMS (S - service provider, i.e. people; W - work procedure; I - instrumentation; M - materials in the complex underground; S - specifications by client) fails, and how it/they fail(s). This work attempts to carry out the blind test by burying fit balls (as voids) under a site with reinforced concrete road and paving block by PolyU team A. The blind test about the void centroid, spread and cover depth was then carried out by PolyU team B without prior information given. Then with this baseline, a marking scheme, acceptance criteria and passing mark were set to test six local commercial service providers, determine their scores and evaluate the performance. A pass is a prerequisite of the award of a service contract of similar nature. In this first attempt of the blind test, results were not satisfactory and it is concluded that 'S-service provider' and 'W-work procedure' amongst SWIMS contributed to most part of the unsatisfactory performance.+

  6. MAPPING SPATIAL MOISTURE CONTENT OF UNSATURATED AGRICULTURAL SOILS WITH GROUND-PENETRATING RADAR

    Directory of Open Access Journals (Sweden)

    O. Shamir

    2016-06-01

    Full Text Available Soil subsurface moisture content, especially in the root zone, is important for evaluation the influence of soil moisture to agricultural crops. Conservative monitoring by point-measurement methods is time-consuming and expensive. In this paper we represent an active remote-sensing tool for subsurface spatial imaging and analysis of electromagnetic physical properties, mostly water content, by ground-penetrating radar (GPR reflection. Combined with laboratory methods, this technique enables real-time and highly accurate evaluations of soils' physical qualities in the field. To calculate subsurface moisture content, a model based on the soil texture, porosity, saturation, organic matter and effective electrical conductivity is required. We developed an innovative method that make it possible measures spatial subsurface moisture content up to a depth of 1.5 m in agricultural soils and applied it to two different unsaturated soil types from agricultural fields in Israel: loess soil type (Calcic haploxeralf, common in rural areas of southern Israel with about 30% clay, 30% silt and 40% sand, and hamra soil type (Typic rhodoxeralf, common in rural areas of central Israel with about 10% clay, 5% silt and 85% sand. Combined field and laboratory measurements and model development gave efficient determinations of spatial moisture content in these fields. The environmentally friendly GPR system enabled non-destructive testing. The developed method for measuring moisture content in the laboratory enabled highly accurate interpretation and physical computing. Spatial soil moisture content to 1.5 m depth was determined with 1–5% accuracy, making our method useful for the design of irrigation plans for different interfaces.

  7. Applicability of Doppler weather radar based rainfall data for runoff ...

    Indian Academy of Sciences (India)

    Radar-based hydrological studies in various countries have proven that ... in view of topographical and terrain constraints, cost restrictions and maintenance- .... SCS Unit Hydrograph (SCS UH) method converts surplus rainfall into runoff at the.

  8. A Wing Pod-based Millimeter Wave Cloud Radar on HIAPER

    Science.gov (United States)

    Vivekanandan, Jothiram; Tsai, Peisang; Ellis, Scott; Loew, Eric; Lee, Wen-Chau; Emmett, Joanthan

    2014-05-01

    One of the attractive features of a millimeter wave radar system is its ability to detect micron-sized particles that constitute clouds with lower than 0.1 g m-3 liquid or ice water content. Scanning or vertically-pointing ground-based millimeter wavelength radars are used to study stratocumulus (Vali et al. 1998; Kollias and Albrecht 2000) and fair-weather cumulus (Kollias et al. 2001). Airborne millimeter wavelength radars have been used for atmospheric remote sensing since the early 1990s (Pazmany et al. 1995). Airborne millimeter wavelength radar systems, such as the University of Wyoming King Air Cloud Radar (WCR) and the NASA ER-2 Cloud Radar System (CRS), have added mobility to observe clouds in remote regions and over oceans. Scientific requirements of millimeter wavelength radar are mainly driven by climate and cloud initiation studies. Survey results from the cloud radar user community indicated a common preference for a narrow beam W-band radar with polarimetric and Doppler capabilities for airborne remote sensing of clouds. For detecting small amounts of liquid and ice, it is desired to have -30 dBZ sensitivity at a 10 km range. Additional desired capabilities included a second wavelength and/or dual-Doppler winds. Modern radar technology offers various options (e.g., dual-polarization and dual-wavelength). Even though a basic fixed beam Doppler radar system with a sensitivity of -30 dBZ at 10 km is capable of satisfying cloud detection requirements, the above-mentioned additional options, namely dual-wavelength, and dual-polarization, significantly extend the measurement capabilities to further reduce any uncertainty in radar-based retrievals of cloud properties. This paper describes a novel, airborne pod-based millimeter wave radar, preliminary radar measurements and corresponding derived scientific products. Since some of the primary engineering requirements of this millimeter wave radar are that it should be deployable on an airborne platform

  9. Application of ground penetrating radar in placer mineral exploration for mapping subsurface sand layers: A case study

    Digital Repository Service at National Institute of Oceanography (India)

    Loveson, V.J.; Barnwal, R.P.; Singh, V.K.; Gujar, A.R.; Rajamanickam, G.V.

    radar reflections using time-domain reflectometry and sedimentological analyses, Sedimentology, v. 47, p. 435-449. Jol, H.M. & Bristow, C.S., 2003. GPR in sediments: advice on data collection, basic processing and interpretation, a good practice... guide, In: Bristow, C.S. and Jol, H.M. (Eds.), GPR in sediments, Geological Society of London, Special Publication, 211. Neal, A., 2004. Ground Penetrating Radar and its use in sedimentology: Principles, Problems and Progress. Earth-Science Reviews...

  10. The Use of Ground Penetrating Radar to Exploring Sedimentary Ore In North-Central Saudi Arabia

    Science.gov (United States)

    Almutairi, Yasir; Almutair, Muteb

    2015-04-01

    Ground Penetrating Radar (GPR) is a non-destructive geophysical method that provides a continuous subsurface profile, without drilling. This geophysical technique has great potential in delineating the extension of bauxites ore in north-central Saudi Arabia. Bauxite is from types sedimentary ores. This study aim to evaluate the effectiveness of Ground Penetrating Radar (GPR) to illustrate the subsurface feature of the Bauxite deposits at some selected mining areas north-central Saudi Arabia. Bauxite is a heterogeneous material that consists of complex metals such as alumina and aluminum. An efficient and cost-effect exploration method for bauxite mine in Saudi Arabia is required. Ground penetrating radar (GPR) measurements have been carrying out along outcrop in order to assess the potential of GPR data for imaging and characterising different lithological facies. To do so, we have tested different antenna frequencies to acquire the electromagnetic signals along a 90 m profile using the IDS system. This system equipped with a 25 MHz antenna that allows investigating the Bauxite layer at shallow depths where the clay layers may existed. Therefore, the 25 MHz frequency antenna has been used in this study insure better resolution of the subsurface and to get more penetration to image the Bauxite layer. After the GPR data acquisition, this data must be processed in order to be more easily visualized and interpreted. Data processing was done using Reflex 6.0 software. A series of tests were carried out in frequency filtering on a sample of radar sections, which was considered to better represent the entire set of data. Our results indicated that the GPR profiling has a very good agreement for mapping the bauxite layer depth at range of 7 m to 11 m. This study has emphasized that the high-resolution GPR method is the robust and cost-effect technique to map the Bauxite layer. The exploration of Bauxite resource using the GPR technique could reduce the number of holes to

  11. Model track studies on fouled ballast using ground penetrating radar and multichannel analysis of surface wave

    Science.gov (United States)

    Anbazhagan, P.; Lijun, Su; Buddhima, Indraratna; Cholachat, Rujikiatkamjorn

    2011-08-01

    Ballast fouling is created by the breakdown of aggregates or outside contamination by coal dust from coal trains, or from soil intrusion beneath rail track. Due to ballast fouling, the conditions of rail track can be deteriorated considerably depending on the type of fouling material and the degree of fouling. So far there is no comprehensive guideline available to identify the critical degree of fouling for different types of fouling materials. This paper presents the identification of degree of fouling and types of fouling using non-destructive testing, namely seismic surface-wave and ground penetrating radar (GPR) survey. To understand this, a model rail track with different degree of fouling has been constructed in Civil engineering laboratory, University of Wollongong, Australia. Shear wave velocity obtained from seismic survey has been employed to identify the degree of fouling and types of fouling material. It is found that shear wave velocity of fouled ballast increases initially, reaches optimum fouling point (OFP), and decreases when the fouling increases. The degree of fouling corresponding after which the shear wave velocity of fouled ballast will be smaller than that of clean ballast is called the critical fouling point (CFP). Ground penetrating radar with four different ground coupled antennas (500 MHz, 800 MHz, 1.6 GHz and 2.3 GHz) was also used to identify the ballast fouling condition. It is found that the 800 MHz ground coupled antenna gives a better signal in assessing the ballast fouling condition. Seismic survey is relatively slow when compared to GPR survey however it gives quantifiable results. In contrast, GPR survey is faster and better in estimating the depth of fouling.

  12. COST Action TU1208 - Working Group 3 - Electromagnetic modelling, inversion, imaging and data-processing techniques for Ground Penetrating Radar

    Science.gov (United States)

    Pajewski, Lara; Giannopoulos, Antonios; Sesnic, Silvestar; Randazzo, Andrea; Lambot, Sébastien; Benedetto, Francesco; Economou, Nikos

    2017-04-01

    This work aims at presenting the main results achieved by Working Group (WG) 3 "Electromagnetic methods for near-field scattering problems by buried structures; data processing techniques" of the COST (European COoperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar" (www.GPRadar.eu, www.cost.eu). The main objective of the Action, started in April 2013 and ending in October 2017, is to exchange and increase scientific-technical knowledge and experience of Ground Penetrating Radar (GPR) techniques in civil engineering, whilst promoting in Europe the effective use of this safe non-destructive technique. The Action involves more than 150 Institutions from 28 COST Countries, a Cooperating State, 6 Near Neighbour Countries and 6 International Partner Countries. Among the most interesting achievements of WG3, we wish to mention the following ones: (i) A new open-source version of the finite-difference time-domain simulator gprMax was developed and released. The new gprMax is written in Python and includes many advanced features such as anisotropic and dispersive-material modelling, building of realistic heterogeneous objects with rough surfaces, built-in libraries of antenna models, optimisation of parameters based on Taguchi's method - and more. (ii) A new freeware CAD was developed and released, for the construction of two-dimensional gprMax models. This tool also includes scripts easing the execution of gprMax on multi-core machines or network of computers and scripts for a basic plotting of gprMax results. (iii) A series of interesting freeware codes were developed will be released by the end of the Action, implementing differential and integral forward-scattering methods, for the solution of simple electromagnetic problems by buried objects. (iv) An open database of synthetic and experimental GPR radargrams was created, in cooperation with WG2. The idea behind this initiative is to give researchers the

  13. COST Action TU1208 - Working Group 1 - Design and realisation of Ground Penetrating Radar equipment for civil engineering applications

    Science.gov (United States)

    Pajewski, Lara; Benedetto, Andrea; D'Amico, Sebastiano; Ferrara, Vincenzo; Frezza, Fabrizio; Persico, Raffaele; Tosti, Fabio

    2017-04-01

    frequency-modulated continuous-wave GPR prototype was designed and realized by an Italian research team; detailled instructions, describing how to build this radar step-by-step, will be available by the end of the Action. The idea behind this initiative is to support and encourage institutes in less research-intensive Countries, who cannot afford a commercial system, to build their own prototype for training purposes and to start familiarizing with the GPR technique. 5. A new stepped-frequency ground-coupled multi-antenna GPR system for road and bridge inspection was developed by 3d-radar (manufacturer based in Norway) and presented during the GPR 2014 conference as a contribution to COST Action TU1208. The starting point was an analogous commercial system, with air-coupled antennas. For road inspection, air-coupled antennas offer practical advantages over ground-coupled antennas (mainly, the possibility to carry out measurements at higher speeds); moreover, they allow enhanced detection of shallow layers inside the road structure. On the other hand, data from ground-coupled array contain much more details from individual scatterers, making them more suitable to image the granularity of the road base materials and for bridge deck inspection, where reinforcement rebar has to be imaged. Ground-coupled GPR systems also provide higher penetrating depth due to a stronger coupling of energy into the ground. The novel stepped-frequency ground-coupled GPR exploits an array of boomerang-shaped monopole elements. 6. Recommendations for the safety of people and equipment during GPR prospecting were produced. Despite the increasing demand of GPR surveys all over the world, safety matters are rarely considered. The Action put efforts into debating them, with scientists and professionals performing GPR surveys. As an outcome of this activity, a book was published where a series of recommendations are provided. These include general hints, recommendations for surveys carried out in

  14. Detecting weather radar clutter using satellite-based nowcasting products

    DEFF Research Database (Denmark)

    Jensen, Thomas B.S.; Gill, Rashpal S.; Overgaard, Søren

    2006-01-01

    This contribution presents the initial results from experiments with detection of weather radar clutter by information fusion with satellite based nowcasting products. Previous studies using information fusion of weather radar data and first generation Meteosat imagery have shown promising results...... for the detecting and removal of clutter. Naturally, the improved spatio-temporal resolution of the Meteosat Second Generation sensors, coupled with its increased number of spectral bands, is expected to yield even better detection accuracies. Weather radar data from three C-band Doppler weather radars...... Application Facility' of EUMETSAT and is based on multispectral images from the SEVIRI sensor of the Meteosat-8 platform. Of special interest is the 'Precipitating Clouds' product, which uses the spectral information coupled with surface temperatures from Numerical Weather Predictions to assign probabilities...

  15. Detection capability of a pulsed Ground Penetrating Radar utilizing an oscilloscope and Radargram Fusion Approach for optimal signal quality

    Science.gov (United States)

    Seyfried, Daniel; Schoebel, Joerg

    2015-07-01

    In scientific research pulsed radars often employ a digital oscilloscope as sampling unit. The sensitivity of an oscilloscope is determined in general by means of the number of digits of its analog-to-digital converter and the selected full scale vertical setting, i.e., the maximal voltage range displayed. Furthermore oversampling or averaging of the input signal may increase the effective number of digits, hence the sensitivity. Especially for Ground Penetrating Radar applications high sensitivity of the radar system is demanded since reflection amplitudes of buried objects are strongly attenuated in ground. Hence, in order to achieve high detection capability this parameter is one of the most crucial ones. In this paper we analyze the detection capability of our pulsed radar system utilizing a Rohde & Schwarz RTO 1024 oscilloscope as sampling unit for Ground Penetrating Radar applications, such as detection of pipes and cables in the ground. Also effects of averaging and low-noise amplification of the received signal prior to sampling are investigated by means of an appropriate laboratory setup. To underline our findings we then present real-world radar measurements performed on our GPR test site, where we have buried pipes and cables of different types and materials in different depths. The results illustrate the requirement for proper choice of the settings of the oscilloscope for optimal data recording. However, as we show, displaying both strong signal contributions due to e.g., antenna cross-talk and direct ground bounce reflection as well as weak reflections from objects buried deeper in ground requires opposing trends for the oscilloscope's settings. We therefore present our Radargram Fusion Approach. By means of this approach multiple radargrams recorded in parallel, each with an individual optimized setting for a certain type of contribution, can be fused in an appropriate way in order to finally achieve a single radargram which displays all

  16. USING GROUND PENETRATING RADAR TO DETERMINE THE TUNNEL LOCATION BURIED UNDER THE GLACIER

    Directory of Open Access Journals (Sweden)

    Deryuga Andrey Mikhaylovich

    2013-09-01

    Full Text Available The works were carried out with the help of ground penetrating radar “Grot-10”. Doublet broadband antennas with the central frequency of 100 MHz were used. Georadar measures the speed of EM waves v in ice-saturated soil and then the value ε′ is calculated. The radargrams received as a result of georadar survey, which represents stacked data (the two-way time is indicated on vertical scale, were transformed into depth sections, which reflect the space structure located below ground. The distance between the bottom landing and buried mountain road near the north tunnel portal is 78,5 m (profile # 1, and the distance from the upper landing is 84,5 m (profile no. 2. Later, in the April 2003 during the hole boring with the diameter 1,2 m the vertical distance between the upper landing, where ground penetrating works were carried out, and the carpet road of the tunnel was calculated. This distance appeared to be 83 m, that means, the discrepancy between boring and georadar data (84,5 m was only 1,5 m. Thus, the results of ground penetrating investigations helped the workers of glacier to make the correct conclusion on time about the location and burial depth of the tunnel.

  17. Automatic Barometric Updates from Ground-Based Navigational Aids

    Science.gov (United States)

    1990-03-12

    ro fAutomatic Barometric Updates US Department from of Transportation Ground-Based Federal Aviation Administration Navigational Aids Office of Safety...tighter vertical spacing controls , particularly for operations near Terminal Control Areas (TCAs), Airport Radar Service Areas (ARSAs), military climb and...E.F., Ruth, J.C., and Williges, B.H. (1987). Speech Controls and Displays. In Salvendy, G., E. Handbook of Human Factors/Ergonomics, New York, John

  18. Resolution of lava tubes with ground penetrating radar: preliminary results from the TubeX project

    Science.gov (United States)

    Esmaeili, S.; Kruse, S.; Garry, W. B.; Whelley, P.; Young, K.; Jazayeri, S.; Bell, E.; Paylor, R.

    2017-12-01

    As early as the mid 1970's it was postulated that planetary tubes or caves on other planetary bodies (i.e., the Moon or Mars) could provide safe havens for human crews, protect life and shield equipment from harmful radiation, rapidly fluctuating surface temperatures, and even meteorite impacts. What is not clear, however, are the exploration methods necessary to evaluate a potential tube-rich environment to locate suitable tubes suitable for human habitation. We seek to address this knowledge gap using a suite of instruments to detect and document tubes in a terrestrial analog study at Lava Beds National Monument, California, USA. Here we describe the results of ground penetrating radar (GPR) profiles and light detection and ranging (LiDAR) scans. Surveys were conducted from the surface and within four lava tubes (Hercules Leg, Skull, Valentine and, Indian Well Caves) with varying flow composition, shape, and complexity. Results are shown across segments of these tubes where the tubes are 10 m in height and the ceilings are 1 - 10 m below the surface. The GPR profiles over the tubes are, as expected, complex, due to scattering from fractures in roof material and three-dimensional heterogeneities. Point clouds derived from the LiDAR scans of both the interior and exterior of the lava tubes provide precise positioning of the tube geometry and depth of the ceiling and floor with respect to the surface topography. GPR profiles over LiDAR-mapped tube cross-sections are presented and compared against synthetic models of radar response to the measured geometry. This comparison will help to better understand the origins of characteristic features in the radar profiles. We seek to identify the optimal data processing and migration approaches to aid lava tube exploration of planetary surfaces.

  19. Civil Engineering Applications of Ground Penetrating Radar: Research Perspectives in COST Action TU1208

    Science.gov (United States)

    Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Slob, Evert; Tosti, Fabio

    2013-04-01

    can be used by GPR operators to identify the signatures generated by uncommon targets or by composite structures. Repeated evaluations of the electromagnetic field scattered by known targets can be performed by a forward solver, in order to estimate - through comparison with measured data - the physics and geometry of the region investigated by the GPR. It is possible to identify three main areas, in the GPR field, that have to be addressed in order to promote the use of this technology in the civil engineering. These are: a) increase of the system sensitivity to enable the usability in a wider range of conditions; b) research novel data processing algorithms/analysis tools for the interpretation of GPR results; c) contribute to the development of new standards and guidelines and to training of end users, that will also help to increase the awareness of operators. In this framework, the COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar", proposed by Lara Pajewski, "Roma Tre" University, Rome, Italy, has been approved in November 2012 and is going to start in April 2013. It is a 4-years ambitious project already involving 17 European Countries (AT, BE, CH, CZ, DE, EL, ES, FI, FR, HR, IT, NL, NO, PL, PT, TR, UK), as well as Australia and U.S.A. The project will be developed within the frame of a unique approach based on the integrated contribution of University researchers, software developers, geophysics experts, Non-Destructive Testing equipment designers and producers, end users from private companies and public agencies. The main objective of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst promoting the effective use of this safe and non-destructive technique in the monitoring of systems. In this interdisciplinary Action, advantages and limitations of GPR will be highlighted, leading to the identification of gaps in knowledge and technology

  20. Integrating ground-penetrating radar and borehole data from a Wadden Sea barrier island

    DEFF Research Database (Denmark)

    Nielsen, Lars; Møller, I.; Nielsen, L. H.

    2009-01-01

    Sea level rise may have large implications for low-gradient barrier coastal systems. This problem motivated an integrated ground-penetrating radar (GPR) and sedimentological study of the Rømø Wadden Sea barrier island. Crossing W-E and N-S-oriented 100 MHz GPR reflection profiles with a total...... island. We document different standard processing steps which lead to increased signal-to-noise ratio, improved resolution and trustworthy GPR-to-borehole correlation. The GPR signals image the subsurface layering with a vertical resolution of ~ 0.2-0.3 m. The penetration depth of the GPR reflection...... conversion of the reflection profiles. The GPR reflections are correlated with sedimentological facies logs, and we test to which extent it is possible to map the architecture of different sedimentary units of the Rømø barrier island based on joint interpretation of the GPR and core data. Detailed...

  1. Application of ground penetrating radar in detecting the hazards and risks of termites and ants in soil levees.

    Science.gov (United States)

    Yang, Xiuhao; Henderson, Gregg; Mao, Lixin; Evans, Ahmad

    2009-08-01

    A ground penetrating radar (GPR) technique was used to detect Formosan subterranean termite (Coptotermes formosanus) and red imported fire ant (Solenopsis invicta) hazards and risks (targets) in a soil levee at the London Avenue Canal in New Orleans, LA. To make this assessment, GPR signal scans were examined for features produced by termite or ant activities and potential sources of food and shelter such as nests, tree roots, and voids (tunnels). The total scanned length of the soil levee was 4,125 m. The average velocity and effective depth of the radar penetration was 0.080 m/ns and 0.61 m, respectively. Four hundred twenty-seven targets were identified. Tree roots (38), voids (31), fire ant nests (209), and metal objects (149) were detected, but no Formosan termite carton nests were identified. The lack of identified termite nests may be related to drowning events at the time to the flood. Based on the target density (TD), the two new floodwall and levee sections that were rebuilt or reinforced after they were destroyed by Hurricane Katrina in 2005 were determined to be at low potential risk from termites and ants. A merging target density (MTD) method indicated a high potential risk near one of the breached sections still remains. Foraging and nesting activity of Formosan subterranean termites and red imported fire ants may be a contributory factor to the levee failure at the London Avenue Canal.

  2. Inspection of a large concrete block containing embedded defects using ground penetrating radar

    Science.gov (United States)

    Eisenmann, David; Margetan, Frank J.; Koester, Lucas; Clayton, Dwight

    2016-02-01

    Ground penetrating radar (GPR), also known as impulse response radar, was used to examine a thick concrete block containing reinforcing steel bars (rebar) and embedded defects. The block was located at the University of Minnesota, measured approximately 7 feet tall by 7 feet wide by 40 inches deep, and was intended to simulate certain aspects of a concrete containment wall at a nuclear power plant. This paper describes the measurements that were made and various analyses of the data. We begin with a description of the block itself and the GPR equipment and methods used in our inspections. The methods include the application of synthetic aperture focusing techniques (SAFT). We then present and discuss GPR images of the block's interior made using 1600-MHz, 900-MHz, and 400-MHz antennas operating in pulse/echo mode. A number of the embedded defects can be seen, and we discuss how their relative detectability can be quantified by comparison to the response from nearby rebar. We next discuss through-transmission measurements made using pairs of 1600-MHz and 900-MHz antennas, and the analysis of that data to deduce the average electromagnetic (EM) wave speed and attenuation of the concrete. Through the 40-inch thickness, attenuation rises approximately linearly with frequency at a rate near 0.7 dB/inch/GHz. However, there is evidence that EM properties vary with depth in the block. We conclude with a brief summary and a discussion of possible future work.

  3. Application of Ground-Penetrating Radar for Detecting Internal Anomalies in Tree Trunks with Irregular Contours.

    Science.gov (United States)

    Li, Weilin; Wen, Jian; Xiao, Zhongliang; Xu, Shengxia

    2018-02-22

    To assess the health conditions of tree trunks, it is necessary to estimate the layers and anomalies of their internal structure. The main objective of this paper is to investigate the internal part of tree trunks considering their irregular contour. In this respect, we used ground penetrating radar (GPR) for non-invasive detection of defects and deteriorations in living trees trunks. The Hilbert transform algorithm and the reflection amplitudes were used to estimate the relative dielectric constant. The point cloud data technique was applied as well to extract the irregular contours of trunks. The feasibility and accuracy of the methods were examined through numerical simulations, laboratory and field measurements. The results demonstrated that the applied methodology allowed for accurate characterizations of the internal inhomogeneity. Furthermore, the point cloud technique resolved the trunk well by providing high-precision coordinate information. This study also demonstrated that cross-section tomography provided images with high resolution and accuracy. These integrated techniques thus proved to be promising for observing tree trunks and other cylindrical objects. The applied approaches offer a great promise for future 3D reconstruction of tomographic images with radar wave.

  4. A systematic method for characterizing the time-range performance of ground penetrating radar

    International Nuclear Information System (INIS)

    Strange, A D

    2013-01-01

    The fundamental performance of ground penetrating radar (GPR) is linked to the ability to measure the signal time-of-flight in order to provide an accurate radar-to-target range estimate. Having knowledge of the actual time range and timing nonlinearities of a trace is therefore important when seeking to make quantitative range estimates. However, very few practical methods have been formally reported in the literature to characterize GPR time-range performance. This paper describes a method to accurately measure the true time range of a GPR to provide a quantitative assessment of the timing system performance and detect and quantify the effects of timing nonlinearity due to timing jitter. The effect of varying the number of samples per trace on the true time range has also been investigated and recommendations on how to minimize the effects of timing errors are described. The approach has been practically applied to characterize the timing performance of two commercial GPR systems. The importance of the method is that it provides the GPR community with a practical method to readily characterize the underlying accuracy of GPR systems. This in turn leads to enhanced target depth estimation as well as facilitating the accuracy of more sophisticated GPR signal processing methods. (paper)

  5. Analysis of the karst aquifer structure of the Lamalou area (Herault, France) with ground penetrating radar

    International Nuclear Information System (INIS)

    Al-Fares, W.; Bakalowicz, M.; Guerin, R.; Dukhan, M.

    2004-01-01

    The study site at Lamalou karst spring Hortus karst plateau) is situated 40 km north of Montpellier in France. It consists of a limestone plateau, drained by a karst conduit discharging as a spring. This conduit extends for a few dozen meters in fractured and karstified limestone rocks, 15 to 70 m below the surface. The conduit is accessible from the surface. The main goal of this study is to analyze the surface part of the karst and to highlight the karstic features and among them the conduit, and to test the performances of ground penetrating radar (GPR) in a karstic environment. This method thus appears particularly well adapted to the analysis of the near-surface (<30 m in depth) structure of a karst, especially when clayey coating or soil that absorbs and attenuates the radar is rare and discontinuous. A GPR pulse EKKO 100 (Sensors and Software) was used on the site with a 50 MHz antenna frequency. The results highlight structures characterizing the karstic environment: The epikarst, bedding planes, fractured and karstified zones, compact and massive rock and karrens, a typical karst landform. One of the sections revealed in detail the main conduit located at a depth of 20 m, and made it possible to determine its geometry. This site offers possibilities of validation of GPR data by giving direct access to the karstic conduit and through two cored boreholes. These direct observations confirm the interpretation of all the GPR sections. (author

  6. Localizing Ground Penetrating RADAR: A Step Towards Robust Autonomous Ground Vehicle Localization

    Science.gov (United States)

    2016-07-14

    can be made on future passes. The highway and subsurface move based on seasonal and water based varia - tions, which offer the potential to reduce the...effect on wave propagation velocity. As a result, the regis- tration process may be impacted when soil moisture content is variable between the baseline

  7. Detection of shallow buried objects using an autoregressive model on the ground penetrating radar signal

    Science.gov (United States)

    Nabelek, Daniel P.; Ho, K. C.

    2013-06-01

    The detection of shallow buried low-metal content objects using ground penetrating radar (GPR) is a challenging task. This is because these targets are right underneath the ground and the ground bounce reflection interferes with their detections. They do not create distinctive hyperbolic signatures as required by most existing GPR detection algorithms due to their special geometric shapes and low metal content. This paper proposes the use of the Autoregressive (AR) modeling method for the detection of these targets. We fit an A-scan of the GPR data to an AR model. It is found that the fitting error will be small when such a target is present and large when it is absent. The ratio of the energy in an Ascan before and after AR model fitting is used as the confidence value for detection. We also apply AR model fitting over scans and utilize the fitting residual energies over several scans to form a feature vector for improving the detections. Using the data collected from a government test site, the proposed method can improve the detection of this kind of targets by 30% compared to the pre-screener, at a false alarm rate of 0.002/m2.

  8. Measurement of Seaward Ground Displacements on Coastal Landfill Area Using Radar Interferometry

    Science.gov (United States)

    Baek, W.-K.; Jung, H.-S.

    2018-04-01

    In order to understand the mechanism of subsidence and help reducing damage, researchers has been observed the line-of-sight subsidence on the Noksan industrial complex using SAR Interferometry(InSAR) and suggested subsidence prediction models. Although these researches explained a spatially uneven ground subsidence near the seaside, they could not have been explained the occurrence of the newly proposed seaward horizontal, especially nearly north-ward, displacement because of the geometric limitation of InSAR measurements. In this study, we measured the seaward ground displacements trend on the coastal landfill area, Noksan Industrial Complex. We set the interferometric pairs from an ascending and a descending orbits strip map data of ALOS PALSAR2. We employed InSAR and MAI stacking approaches for the both orbits respectively in order to improve the measurement. Finally, seaward deformation was estimated by retrieving three-dimensional displacements from multi-geometric displacements. As a results, maximally 3.3 and 0.7 cm/year of ground displacements for the vertical and seaward directions. In further study, we plan to generate InSAR and MAI stacking measurements with additional SAR data to mitigate tropospheric effect and noise well. Such a seaward observation approach using spaceborne radar is expected to be effective in observing the long-term movements on coastal landfill area.

  9. MEASUREMENT OF SEAWARD GROUND DISPLACEMENTS ON COASTAL LANDFILL AREA USING RADAR INTERFEROMETRY

    Directory of Open Access Journals (Sweden)

    W.-K. Baek

    2018-04-01

    Full Text Available In order to understand the mechanism of subsidence and help reducing damage, researchers has been observed the line-of-sight subsidence on the Noksan industrial complex using SAR Interferometry(InSAR and suggested subsidence prediction models. Although these researches explained a spatially uneven ground subsidence near the seaside, they could not have been explained the occurrence of the newly proposed seaward horizontal, especially nearly north-ward, displacement because of the geometric limitation of InSAR measurements. In this study, we measured the seaward ground displacements trend on the coastal landfill area, Noksan Industrial Complex. We set the interferometric pairs from an ascending and a descending orbits strip map data of ALOS PALSAR2. We employed InSAR and MAI stacking approaches for the both orbits respectively in order to improve the measurement. Finally, seaward deformation was estimated by retrieving three-dimensional displacements from multi-geometric displacements. As a results, maximally 3.3 and 0.7 cm/year of ground displacements for the vertical and seaward directions. In further study, we plan to generate InSAR and MAI stacking measurements with additional SAR data to mitigate tropospheric effect and noise well. Such a seaward observation approach using spaceborne radar is expected to be effective in observing the long-term movements on coastal landfill area.

  10. Analysis on Target Detection and Classification in LTE Based Passive Forward Scattering Radar

    Directory of Open Access Journals (Sweden)

    Raja Syamsul Azmir Raja Abdullah

    2016-09-01

    Full Text Available The passive bistatic radar (PBR system can utilize the illuminator of opportunity to enhance radar capability. By utilizing the forward scattering technique and procedure into the specific mode of PBR can provide an improvement in target detection and classification. The system is known as passive Forward Scattering Radar (FSR. The passive FSR system can exploit the peculiar advantage of the enhancement in forward scatter radar cross section (FSRCS for target detection. Thus, the aim of this paper is to show the feasibility of passive FSR for moving target detection and classification by experimental analysis and results. The signal source is coming from the latest technology of 4G Long-Term Evolution (LTE base station. A detailed explanation on the passive FSR receiver circuit, the detection scheme and the classification algorithm are given. In addition, the proposed passive FSR circuit employs the self-mixing technique at the receiver; hence the synchronization signal from the transmitter is not required. The experimental results confirm the passive FSR system’s capability for ground target detection and classification. Furthermore, this paper illustrates the first classification result in the passive FSR system. The great potential in the passive FSR system provides a new research area in passive radar that can be used for diverse remote monitoring applications.

  11. Analysis on Target Detection and Classification in LTE Based Passive Forward Scattering Radar.

    Science.gov (United States)

    Raja Abdullah, Raja Syamsul Azmir; Abdul Aziz, Noor Hafizah; Abdul Rashid, Nur Emileen; Ahmad Salah, Asem; Hashim, Fazirulhisyam

    2016-09-29

    The passive bistatic radar (PBR) system can utilize the illuminator of opportunity to enhance radar capability. By utilizing the forward scattering technique and procedure into the specific mode of PBR can provide an improvement in target detection and classification. The system is known as passive Forward Scattering Radar (FSR). The passive FSR system can exploit the peculiar advantage of the enhancement in forward scatter radar cross section (FSRCS) for target detection. Thus, the aim of this paper is to show the feasibility of passive FSR for moving target detection and classification by experimental analysis and results. The signal source is coming from the latest technology of 4G Long-Term Evolution (LTE) base station. A detailed explanation on the passive FSR receiver circuit, the detection scheme and the classification algorithm are given. In addition, the proposed passive FSR circuit employs the self-mixing technique at the receiver; hence the synchronization signal from the transmitter is not required. The experimental results confirm the passive FSR system's capability for ground target detection and classification. Furthermore, this paper illustrates the first classification result in the passive FSR system. The great potential in the passive FSR system provides a new research area in passive radar that can be used for diverse remote monitoring applications.

  12. Magnetometry and Ground-Penetrating Radar Studies in the Sihuas Valley, Peru

    Science.gov (United States)

    Wisnicki, E.; Papadimitrios, K.; Bank, C.

    2013-12-01

    The Quillcapampa la Antigua site in Peru's Sihuas Valley is a settlement from Peru's Middle Horizon (600-100 A.D.). Archaeological interest in the area stems from the question of whether ancient civilizations were able to have extensive state control of distant groups, or whether state influence occurred through less direct ties (e.g., marriage, religion, or trade). Our geophysical surveys are preliminary to archaeological digging in the area. Ground-penetrating radar and magnetometry attempt to locate areas of interest for focused archaeological excavation, characterize the design of architectural remains and burial mounds in the area, and allow archaeologists to interpret the amount of influence the Wari civilization had on the local residents.

  13. Ground-penetrating radar investigations conducted in the 100 areas, Hanford Site: Fiscal Year 1992

    International Nuclear Information System (INIS)

    Bergstrom, K.A.

    1994-01-01

    During Fiscal Year 1992, the Geophysics Group conducted forty- five Ground-Penetrating Radar (GPR) surveys in the 100 Areas (Figure 1) - Objectives for the investigations varied, from locating cribs, trenches and septic systems to helping site boreholes. The results of each investigation were delivered to clients in the form of a map that summarized the interpretation of a given site. No formal reports were prepared. The purpose of this document is to show where and why each of the surveys was conducted. The data and interpretation of each survey are available by contacting the Westinghouse Hanford Company, Geophysics Group. A map showing the location and basic parameters of each survey can be found in the Appendices of this report

  14. Application of ground-penetrating radar at McMurdo Station, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Stefano, J.E.

    1992-01-01

    Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

  15. Application of ground-penetrating radar at McMurdo Station, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Stefano, J.E.

    1992-05-01

    Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

  16. INVESTIGATION OF GROUND PENETRATING RADAR FOR DETECTION OF ROAD SUBSIDENCE NORTHCOAST OF JAKARTA, INDONESIA

    Directory of Open Access Journals (Sweden)

    Kris Budiono

    2017-07-01

    Full Text Available A survey of Ground Penetrating Radar (GPR was conducted in the coastal zone of northern part of Jakarta, Indonesia. The purpose of this survey was to provide the subsurface of coastal Quaternary sedimentary features and stratigraphy disturbances associated with induce post road subsidence 2009. The possibility of subsurface lithology disturbance shown by the GPR record. This record resulted from GPR methods using SIR system 20 GSSI, 270 MHz and 400 MHz and MLF 3200 transducer. The method is a promising tool for resolving changes of physical properties in subsurface lithology condition at the natural scale due to composition changes of physical properties.The reflection data resulted that GPR can distinguish between image the basic geometry forms such as lithology , structure geology , soil and subsurface utilities condition

  17. Application of ground-penetrating radar at McMurdo Station, Antarctica

    International Nuclear Information System (INIS)

    Stefano, J.E.

    1992-01-01

    Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station

  18. Spatially Extensive Ground-Penetrating Radar Observations during NASA's 2017 SnowEx campaign

    Science.gov (United States)

    McGrath, D.; Webb, R.; Marshall, H. P.; Hale, K.; Molotch, N. P.

    2017-12-01

    Quantifying snow water equivalent (SWE) from space remains a significant challenge, particularly in regions of forest cover or complex topography that result in high spatial variability and present difficulties for existing remote sensing techniques. Here we use extensive ground-penetrating radar (GPR) surveys during the NASA SnowEx 2017 campaign to characterize snow depth, density, and SWE across the Grand Mesa field site with a wide range of varying canopy and topographical conditions. GPR surveys, which are sensitive to snow density and microstructure, provide independent information that can effectively constrain leading airborne and spaceborne SWE retrieval approaches. We find good agreement between GPR observations and a suite of supporting in situ measurements, including snowpits, probe lines, and terrestrial LiDAR. Preliminary results illustrate the role of vegetation in controlling SWE variability, with the greatest variability found in dense forests and lowest variability found in open meadows.

  19. Features of Ground Penetrating Radars for the exploration of planetary subsurface

    Science.gov (United States)

    Burghignoli, P.; Cereti, A.; Fiore, E.; Galli, A.; Pajewski, L.; Pettinelli, E.; Pisani, A.; Schettini, G.; Ticconi, F.

    2003-04-01

    Among the various applications of Surface or Ground Penetrating Radars (GPRs), the possibility of achieving useful information about the characterization of planetary soils represents a topic which has deserved particular interest in recent times [1]. The present work intends to analyze various critical aspects related to the GPR capability of properly investigating the subsurface structure, also emphasizing what kind of practical solutions seem to be more suitable to this purpose. Some basic aspects have to be considered, which are peculiar of this type of problem, e.g.: i) the poor information achievable up to now on both the composition and the stratigraphy of planet soils; ii) the typical bulk and weight limitations for instruments when used in onboard rovers for in-situ measurements. As regards the first aspect, additional knowledge should generally be required on the electromagnetic parameters (permittivity, permeability, and conductivity) of the upper subsoil layers in order to extract useful information from the GPR data. The use of different types of sensors, which can be integrated in an overall "sounding package" [1], is a useful way of characterizing more precisely such electromagnetic parameters. Consequently, GPR can primarily be used to get data on the unknown stratigraphy. The second aspect implies fundamental constraints in the design of GPR, involving the choice of the type of radar, the relevant electronic equipment for signal processing, the antenna design, etc. In addition to standard types of "pulsed" GPR, a specific study has been performed on "step-frequency" GPRs, which appear to be attractive due to their low-cost and simple electronic circuitry. As concerns the choice of the radiating elements, the most suitable configurations of GPR antennas have been investigated and compared in terms of dimensions and radiation parameters. New specific antenna configurations have been proposed, designed, and tested. Finally, numerical simulations have

  20. Application of Ground Penetrating Radar Supported by Mineralogical-Geochemical Methods for Mapping Unroofed Cave Sediments

    Directory of Open Access Journals (Sweden)

    Teja Čeru

    2018-04-01

    Full Text Available Ground penetrating radar (GPR using a special unshielded 50 MHz Rough Terrain Antenna (RTA in combination with a shielded 250 MHz antenna was used to study the capability of this geophysical method for detecting cave sediments. Allochthonous cave sediments found in the study area of Lanski vrh (W Slovenia are now exposed on the karst surface in the so-called “unroofed caves” due to a general lowering of the surface (denudation of carbonate rocks and can provide valuable evidence of the karst development. In the first phase, GPR profiles were measured at three test locations, where cave sediments are clearly evident on the surface and appear with flowstone. It turned out that cave sediments are clearly visible on GPR radargrams as areas of strong signal attenuation. Based on this finding, GPR profiling was used in several other places where direct indicators of unroofed caves or other indicators for speleogenesis are not present due to strong surface reshaping. The influence of various field conditions, especially water content, on GPR measurements was also analysed by comparing radargrams measured in various field conditions. Further mineralogical-geochemical analyses were conducted to better understand the factors that influence the attenuation in the area of cave sediments. Samples of cave sediments and soils on carbonate rocks (rendzina were taken for X-ray diffraction (XRD and X-ray fluorescence (XRF analyses to compare the mineral and geochemical compositions of both sediments. Results show that cave sediments contain higher amounts of clay minerals and iron/aluminium oxides/hydroxides which, in addition to the thickness of cave sediments, can play an important role in the depth of penetration. Differences in the mineral composition also lead to water retention in cave sediments even through dry periods which additionally contribute to increased attenuation with respect to surrounding soils. The GPR method has proven to be reliable for

  1. Internal structure of a barrier beach as revealed by ground penetrating radar (GPR): Chesil beach, UK

    Science.gov (United States)

    Bennett, Matthew R.; Cassidy, Nigel J.; Pile, Jeremy

    2009-03-01

    Chesil Beach (Dorset) is one of the most famous coastal landforms on the British coast. The gravel beach is over 18 km long and is separated for much of its length from land by a tidal lagoon known as The Fleet. The beach links the Isle of Portland in the east to the mainland in the west. Despite its iconic status there is little available information on its internal geometry and evolutionary history. Here we present a three-fold model for the evolution of Chesil Beach based on a series of nine ground penetrating radar (GPR) traverses located at three sites along its length at Abbotsbury, Langton Herring and at Ferry Bridge. The GPR traverses reveal a remarkably consistent picture of the internal structure of this barrier beach. The first phase of evolution involves the landward transgression of a small sand and gravel beach which closed upon the coast leading to deposition of freshwater peat between 5 and 7 k yr BP. The second evolutionary phase involves the 'bulking-out' of the beach during continued sea level rise, but in the presence of abundant gravel supplied by down-drift erosion of periglacial slope deposits. This episode of growth was associated with a series of washover fans which accumulated on the landward flank of the barrier increasing its breadth and height but without significant landward transgression of the barrier as a whole. The final phase in the evolution of Chesil Beach involves the seaward progradation of the beach crest and upper beach face associated with continued sediment abundance, but during a still-stand or slight fall in relative sea level. This phase may provide further evidence of a slight fall in relative sea level noted elsewhere along the South Coast of Britain and dated to between 1.2 and 2.4 k yr BP. Subsequently the barrier appears to have become largely inactive, except for the reworking of sediment on the beach face during storm events. The case study not only refines the evolutionary picture of Chesil Beach, but

  2. Broadband Ground Penetrating Radar with conformal antennas for subsurface imaging from a rover

    Science.gov (United States)

    Stillman, D. E.; Oden, C. P.; Grimm, R. E.; Ragusa, M.

    2015-12-01

    Ground-Penetrating Radar (GPR) allows subsurface imaging to provide geologic context and will be flown on the next two martian rovers (WISDOM on ExoMars and RIMFAX on Mars 2020). The motivation of our research is to minimize the engineering challenges of mounting a GPR antenna to a spacecraft, while maximizing the scientific capabilities of the GPR. The scientific capabilities increase with the bandwidth as it controls the resolution. Furthermore, ultra-wide bandwidth surveys allow certain mineralogies and rock units to be discriminated based on their frequency-dependent EM or scattering properties. We have designed and field-tested a prototype GPR that utilizes bi-static circularly polarized spiral antennas. Each antenna has a physical size of 61 x 61 x 4 cm, therefore two antennas could be mounted to the underbelly of a MSL-class rover. Spiral antennas were chosen because they have an inherent broadband response and provide a better low frequency response compared with similarly sized linearly polarized antennas. A horizontal spiral radiator emits energy both upward and downward directions. After the radiator is mounted to a metal surface (i.e. the underside of a rover), a cavity is formed that causes the upward traveling energy to reverberate and cause unwanted interference. This interference is minimized by 1) using a high metallization ratio on the spiral to reduce cavity emissions, and 2) placing absorbing material inside the cavity. The resulting antennas provide high gain (0 to 8 dBi) from 200 to 1000 MHz. The low frequency response can be improved by increasing the antenna thickness (i.e., cavity depth). In an initial field test, the antennas were combined with impulse GPR electronics that had ~140 dB of dynamic range (not including antennas) and a sand/clay interface 7 feet deep was detected. To utilize the full bandwidth the antennas, a gated Frequency Modulated Continuous Waveform system will be developed - similar to RIMFAX. The goal is to reach a

  3. GROUND PENETRATING RADAR INVESTIGATIONS FOR ARCHITECTURAL HERITAGE PRESERVATION OF THE HABIB SAKAKINI PALACE, CAIRO, EGYPT

    Directory of Open Access Journals (Sweden)

    Sayed HEMEDA

    2012-09-01

    Full Text Available The modern architectural heritage of Egypt is both varied and vast. It covers all nonecclesiastical buildings, important monumental structures (mansions, municipal buildings in the history of architecture, as well as more common buildings. They include houses (from mansions to simple dwellings, public buildings (schools, administrative buildings, hospitals, industrial buildings (factories, warehouses, mills, bridges, monastic dependencies (drinking foundations, gardens and any other modern structures that fall within the category of monuments and comprise the Egyptian cultural heritage. We present herein a comprehensive Ground Penetration Radar (GPR investigation and hazard assessment for the rehabilitation and strengthening of Habib Sakakini’s Palace, in Cairo, considered one of the most significant architectural heritage sites in Egypt. The palace is located on an ancient water pond at the eastern side of the Egyptian gulf, beside the Sultan Bebris Al-Bondoqdary mosque, a place also called “Prince Qraja al-Turkumany pond”. That pond was drained by Habib Sakakini in 1892, to construct his famous palace in 1897. Eight hundred meters of Ground Penetration Radar (GPR profiling were conducted, to monitor the subsurface conditions. 600 meters were made in the surrounding area of the Palace and 200 m at the basement. The aim was to monitor the soil conditions beneath and around the Palace and to identify potential geological discontinuities, or the presence of faults and cavities. A suitable single and dual antenna were used (500-100 MHZ to penetrate to the desired depth of 7 meters (ASTM D6432. The GPR was also used to detect the underground water. At the building basement the GPR was used to identify the foundation thickness and the soil - basement interface, as well as for the inspection of cracks in some supporting columns, piers and masonry walls. All the results, together with the seismic hazard analysis, will be used for a complete

  4. Evidence for ground-ice occurrence on asteroid Vesta using Dawn bistatic radar observations

    Science.gov (United States)

    Palmer, E. M.; Heggy, E.; Kofman, W. W.

    2017-12-01

    From 2011 to 2012, the Dawn spacecraft orbited asteroid Vesta, the first of its two targets in the asteroid belt, and conducted the first bistatic radar (BSR) experiment at a small-body, during which Dawn's high-gain communications antenna is used to transmit radar waves that scatter from Vesta's surface toward Earth at high incidence angles just before and after occultation of the spacecraft behind the asteroid. Among the 14 observed mid-latitude forward-scatter reflections, the radar cross section ranges from 84 ± 8 km2 (near Saturnalia Fossae) to 3,588 ± 200 km2 (northwest of Caparronia crater), implying substantial spatial variation in centimeter- to decimeter-scale surface roughness. The compared distributions of surface roughness and subsurface hydrogen concentration [H]—measured using data from Dawn's BSR experiment and Gamma Ray and Neutron Spectrometer (GRaND), respectively—reveal the occurrence of heightened subsurface [H] with smoother terrains that cover tens of square kilometers. Furthermore, unlike on the Moon, we observe no correlation between surface roughness and surface ages on Vesta—whether the latter is derived from lunar or asteroid-flux chronology [Williams et al., 2014]—suggesting that cratering processes alone are insufficient to explain Vesta's surface texture at centimeter-to-decimeter scales. Dawn's BSR observations support the hypothesis of transient melting, runoff and recrystallization of potential ground-ice deposits, which are postulated to flow along fractures after an impact, and provide a mechanism for the smoothing of otherwise rough, fragmented impact ejecta. Potential ground-ice presence within Vesta's subsurface was first proposed by Scully et al. [2014], who identified geomorphological evidence for transient water flow along several of Vesta's crater walls using Dawn Framing Camera images. While airless, differentiated bodies such as Vesta and the Moon are thought to have depleted their initial volatile content

  5. A forward model for ground penetrating radar imaging of buried perfect electric conductors within the physical optics approximation

    DEFF Research Database (Denmark)

    Polat, Burak; Meincke, Peter

    2004-01-01

    A forward model for ground penetrating radar imaging of buried 3-D perfect electric conductors is addressed within the framework of diffraction tomography. The similarity of the present forward model derived within the physical optics approximation with that derived within the first Born...

  6. Inversion and sensitivity analysis of ground penetrating radar data with waveguide dispersion using deterministic and Markov chain Monte Carlo methods

    NARCIS (Netherlands)

    Bikowski, J.; Huisman, J.A.; Vrugt, J.A.; Vereecken, H.; van der Kruk, J.

    2012-01-01

    Ground-penetrating radar (GPR) data affected by waveguide dispersion are not straightforward to analyse. Therefore, waveguide dispersed common midpoint measurements are typically interpreted using so-called dispersion curves, which describe the phase velocity as a function of frequency. These

  7. THE RESULTS OF THE DEFECT PLACES INVESTIGATION OF DONETSK RAILWAY ROAD BED BY GROUND PENETRATING RADAR COMPLEX

    Directory of Open Access Journals (Sweden)

    V. D. Petrenko

    2014-10-01

    Full Text Available Purpose. Defective places definition of road bed at ground penetrating radar is examined. Methodology. For achievement of this goal the experimental research on ground penetrating radar inspection of road bed defective places of the Donetsk Railway, which are caused by a complex of various reasons of geotechnical and constructive character, were conducted. Findings. According to these diagnostic results of road bed on the three districts of the Donetsk Railway is revealed the main causes which lead to the defects appearance, deformities and injuries in it, there is abuse of process parameters and modify its physic mechanical soil properties of natural and technology-related factors. As it is established, the use of ground penetrating radar of series “Losa” on the railways of Ukraine allows searching ballast tank in the body of road bed, defining damp places in soil road bed and foundations, to find arrangement of foreign matter in the soil road bed and work search heterogeneity and places weakening soil. In addition, the use of ground penetrating radar provides rapid detection of defects, deformation and damage of railway track, especially in areas the most dangerous for rolling stock that creates the high level security at the main and auxiliary lines of Ukrzaliznytsia. In conducting the research was justified the high level of reliability and performance with autonomous use of ground penetrating radar. Originality. In modern conditions of defects determination, deformations and damages by traditional methods with application of engineering-geological investigations, it is impossible in connection with their insufficient efficiency. Therefore the using of highly effective methodology of expeditious tool identification of defective places allows reducing significantly the periods of repair of a railway track which is very important for introduction of the high-speed movement on the Ukrainian Railways. Practical value. On the basis of the

  8. GPM GROUND VALIDATION AIRBORNE SECOND GENERATION PRECIPITATION RADAR (APR-2) GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Second Generation Airborne Precipitation Radar (APR-2) is a dual-frequency (13 GHz and 35 GHz), Doppler, dual-polarization radar system. It has a downward...

  9. Real-Time Landmine Detection with Ground-Penetrating Radar Using Discriminative and Adaptive Hidden Markov Models

    Directory of Open Access Journals (Sweden)

    Ho KC

    2005-01-01

    Full Text Available We propose a real-time software system for landmine detection using ground-penetrating radar (GPR. The system includes an efficient and adaptive preprocessing component; a hidden Markov model- (HMM- based detector; a corrective training component; and an incremental update of the background model. The preprocessing is based on frequency-domain processing and performs ground-level alignment and background removal. The HMM detector is an improvement of a previously proposed system (baseline. It includes additional pre- and postprocessing steps to improve the time efficiency and enable real-time application. The corrective training component is used to adjust the initial model parameters to minimize the number of misclassification sequences. This component could be used offline, or online through feedback to adapt an initial model to specific sites and environments. The background update component adjusts the parameters of the background model to adapt it to each lane during testing. The proposed software system is applied to data acquired from three outdoor test sites at different geographic locations, using a state-of-the-art array GPR prototype. The first collection was used as training, and the other two (contain data from more than 1200 m of simulated dirt and gravel roads for testing. Our results indicate that, on average, the corrective training can improve the performance by about 10% for each site. For individual lanes, the performance gain can reach 50%.

  10. Using ground penetrating radar in levee assessment to detect small scale animal burrows

    Science.gov (United States)

    Chlaib, Hussein K.; Mahdi, Hanan; Al-Shukri, Haydar; Su, Mehmet M.; Catakli, Aycan; Abd, Najah

    2014-04-01

    Levees are civil engineering structures built to protect human lives, property, and agricultural lands during flood events. To keep these important structures in a safe condition, continuous monitoring must be performed regularly and thoroughly. Small rodent burrows are one of the major defects within levees; however, their early detection and repair helps in protecting levees during flooding events. A set of laboratory experiments was conducted to analyze the polarity change in GPR signals in the presence of subsurface voids and water-filled cavities. Ground Penetrating Radar (GPR) surveys using multi frequency antennas (400 MHz and 900 MHz) were conducted along an 875 meter section of the Lollie Levee near Conway, Arkansas, USA, to assess the levee's structural integrity. Many subsurface animal burrows, water-filled cavities, clay clasts, and metallic objects were investigated and identified. These anomalies were located at different depths and have different sizes. To ground truth the observations, hand dug trenches were excavated to confirm several anomalies. Results show an excellent match between GPR interpreted anomalies and the observed features. In-situ dielectric constant measurements were used to calculate the feature depths. The results of this research show that the 900 MHz antenna has more advantages over the 400 MHz antenna.

  11. Ground penetrating radar and direct current resistivity evaluation of the desiccation test cap, Savannah River Site

    International Nuclear Information System (INIS)

    Wyatt, D.E.; Cumbest, R.J.

    1996-04-01

    The Savannah River Site (SRS) has a variety of waste units that may be temporarily or permanently stabilized by closure using an impermeable cover to prevent groundwater infiltration. The placement of an engineered kaolin clay layer over a waste unit is an accepted and economical technique for providing an impermeable cover but the long term stability and integrity of the clay in non-arid conditions is unknown. A simulated kaolin cap has been constructed at the SRA adjacent to the Burial Ground Complex. The cap is designed to evaluate the effects of desiccation on clay integrity, therefore half of the cap is covered with native soil to prevent drying, while the remainder of the cap is exposed. Measurements of the continuing impermeability of a clay cap are difficult because intrusive techniques may locally compromise the structure. Point measurements made to evaluate clay integrity, such as those from grid sampling or coring and made through a soil cover, may miss cracks, joints or fissures, and may not allow for mapping of the lateral extent of elongate features. Because of these problems, a non-invasive technique is needed to map clay integrity, below a soil or vegetation cover, which is capable of moderate to rapid investigation speeds. Two non-intrusive geophysical techniques, direct current resistivity and ground penetrating radar (GPR), have been successful at the SRS in geologically mapping shallow subsurface clay layers. The applicability of each technique in detecting the clay layer in the desiccation test cap and associated anomalies was investigated

  12. Ground penetrating radar survey across the Bok Bak fault, Kedah, Malaysia

    International Nuclear Information System (INIS)

    Yuniarti Ulfa; Nur Fathin Mohd Jamel; Mardiana Samsuardi

    2013-01-01

    A ground penetrating radar (GPR) survey was done across the Bok Bak Fault zone in Baling, Kedah in order to investigate the shallow subsurface geology of the Bok Bak fault zone, its extension and associated weak zones within the study area. GPR data acquisition was compared with visual inspection on the slope of the outcrop. Ten GPR profiles were acquired using 250 MHz GPR frequency. Basic data processing and filtering to reduce some noise and unwanted signal was done using MALA RAMAC Ground Vision software. The data penetrate around 2 meters in depth for all survey lines. In most lines shows clear images of shallowest Bok Bak Fault (NW trending) as detected at distance of 28 m horizontal marker. It also exhibits several sets of faults as a result of Bok Bak Fault deformation, including the conjugate NE trending fault (Lubok Merbau Fault). Active seismicity encompasses the Malay-Thai Peninsular trigger the changes of Bok Bak Fault dipping direction, steeper dips of conjugate faults and faults or fractures rotational movement. (author)

  13. Doppler Radar and Cloud-to-Ground Lightning Observations of a Severe Outbreak of Tropical Cyclone Tornadoes

    Science.gov (United States)

    McCaul, Eugene W., Jr.; Buechler, Dennis; Cammarata, Michael; Arnold, James E. (Technical Monitor)

    2002-01-01

    Data from a single WSR-88D Doppler radar and the National Lightning Detection Network are used to examine the characteristics of the convective storms that produced a severe tornado outbreak within Tropical Storm Beryl's remnants on 16 August 1994. Comparison of the radar data with reports of tornadoes suggests that only 12 cells produced the 29 tornadoes that were documented in Georgia and the Carolinas on that date. Six of these cells spawned multiple tornadoes, and the radar data confirm the presence of miniature supercells. One of the cells was identifiable on radar for 11 hours, spawning tornadoes over a time period spanning approximately 6.5 hours. Time-height analyses of the three strongest supercells are presented in order to document storm kinematic structure and evolution. These Beryl mini-supercells were comparable in radar-observed intensity but much more persistent than other tropical cyclone-spawned tornadic cells documented thus far with Doppler radars. Cloud-to-ground lightning data are also examined for all the tornadic cells in this severe swarm-type tornado outbreak. These data show many of the characteristics of previously reported heavy-precipitation supercells. Lightning rates were weak to moderate, even in the more intense supercells, and in all the storms the lightning flashes were almost entirely negative in polarity. No lightning at all was detected in some of the single-tornado storms. In the stronger cells, there is some evidence that lightning rates can decrease during tornadogenesis, as has been documented before in some midlatitude tornadic storms. A number of the storms spawned tornadoes just after producing their final cloud-to-ground lightning flashes. These findings suggest possible benefits from implementation of observing systems capable of monitoring intracloud as well as cloud-to-ground lightning activity.

  14. Mars, accessing the third dimension: a software tool to exploit Mars ground penetrating radars data.

    Science.gov (United States)

    Cantini, Federico; Ivanov, Anton B.

    2016-04-01

    The Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), on board the ESA's Mars Express and the SHAllow RADar (SHARAD), on board the NASA's Mars Reconnaissance Orbiter are two ground penetrating radars (GPRs) aimed to probe the crust of Mars to explore the subsurface structure of the planet. By now they are collecting data since about 10 years covering a large fraction of the Mars surface. On the Earth GPRs collect data by sending electromagnetic (EM) pulses toward the surface and listening to the return echoes occurring at the dielectric discontinuities on the planet's surface and subsurface. The wavelengths used allow MARSIS EM pulses to penetrate the crust for several kilometers. The data products (Radargrams) are matrices where the x-axis spans different sampling points on the planet surface and the y-axis is the power of the echoes over time in the listening window. No standard way to manage this kind of data is established in the planetary science community and data analysis and interpretation require very often some knowledge of radar signal processing. Our software tool is aimed to ease the access to this data in particular to scientists without a specific background in signal processing. MARSIS and SHARAD geometrical data such as probing point latitude and longitude and spacecraft altitude, are stored, together with relevant acquisition metadata, in a geo-enabled relational database implemented using PostgreSQL and PostGIS. Data are extracted from official ESA and NASA released data using self-developed python classes and scripts and inserted in the database using OGR utilities. This software is also aimed to be the core of a collection of classes and script to implement more complex GPR data analysis. Geometrical data and metadata are exposed as WFS layers using a QGIS server, which can be further integrated with other data, such as imaging, spectroscopy and topography. Radar geometry data will be available as a part of the iMars Web

  15. Construction of Polarimetric Radar-Based Reference Rain Maps for the Iowa Flood Studies Campaign

    Science.gov (United States)

    Petersen, Walt; Krajewski, Witek; Wolff, David; Gatlin, Patrick

    2015-04-01

    The Global Precipitation Measurement (GPM) Mission Iowa Flood Studies (IFloodS) campaign was conducted in central and northeastern Iowa during the months of April-June, 2013. Specific science objectives for IFloodS included quantification of uncertainties in satellite and ground-based estimates of precipitation, 4-D characterization of precipitation physical processes and associated parameters (e.g., size distributions, water contents, types, structure etc.), assessment of the impact of precipitation estimation uncertainty and physical processes on hydrologic predictive skill, and refinement of field observations and data analysis approaches as they pertain to future GPM integrated hydrologic validation and related field studies. In addition to field campaign archival of raw and processed satellite data (including precipitation products), key ground-based platforms such as the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms, and a large network of 2D Video and Parsivel disdrometers were deployed. In something of a canonical approach, the radar (NPOL in particular), gauge and disdrometer observational assets were deployed to create a consistent high-quality distributed (time and space sampling) radar-based ground "reference" rainfall dataset, with known uncertainties, that could be used for assessing the satellite-based precipitation products at a range of space/time scales. Subsequently, the impact of uncertainties in the satellite products could be evaluated relative to the ground-benchmark in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction. Relative to establishing the ground-based "benchmark", numerous avenues were pursued in the making and verification of IFloodS "reference" dual-polarimetric radar-based rain maps, and this study documents the process and results as they pertain specifically

  16. Construction of Polarimetric Radar-Based Reference Rain Maps for the Iowa Flood Studies Campaign

    Science.gov (United States)

    Petersen, Walter; Wolff, David; Krajewski, Witek; Gatlin, Patrick

    2015-01-01

    The Global Precipitation Measurement (GPM) Mission Iowa Flood Studies (IFloodS) campaign was conducted in central and northeastern Iowa during the months of April-June, 2013. Specific science objectives for IFloodS included quantification of uncertainties in satellite and ground-based estimates of precipitation, 4-D characterization of precipitation physical processes and associated parameters (e.g., size distributions, water contents, types, structure etc.), assessment of the impact of precipitation estimation uncertainty and physical processes on hydrologic predictive skill, and refinement of field observations and data analysis approaches as they pertain to future GPM integrated hydrologic validation and related field studies. In addition to field campaign archival of raw and processed satellite data (including precipitation products), key ground-based platforms such as the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms, and a large network of 2D Video and Parsivel disdrometers were deployed. In something of a canonical approach, the radar (NPOL in particular), gauge and disdrometer observational assets were deployed to create a consistent high-quality distributed (time and space sampling) radar-based ground "reference" rainfall dataset, with known uncertainties, that could be used for assessing the satellite-based precipitation products at a range of space/time scales. Subsequently, the impact of uncertainties in the satellite products could be evaluated relative to the ground-benchmark in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction. Relative to establishing the ground-based "benchmark", numerous avenues were pursued in the making and verification of IFloodS "reference" dual-polarimetric radar-based rain maps, and this study documents the process and results as they pertain specifically

  17. Using pattern recognition to automatically localize reflection hyperbolas in data from ground penetrating radar

    Science.gov (United States)

    Maas, Christian; Schmalzl, Jörg

    2013-08-01

    Ground Penetrating Radar (GPR) is used for the localization of supply lines, land mines, pipes and many other buried objects. These objects can be recognized in the recorded data as reflection hyperbolas with a typical shape depending on depth and material of the object and the surrounding material. To obtain the parameters, the shape of the hyperbola has to be fitted. In the last years several methods were developed to automate this task during post-processing. In this paper we show another approach for the automated localization of reflection hyperbolas in GPR data by solving a pattern recognition problem in grayscale images. In contrast to other methods our detection program is also able to immediately mark potential objects in real-time. For this task we use a version of the Viola-Jones learning algorithm, which is part of the open source library "OpenCV". This algorithm was initially developed for face recognition, but can be adapted to any other simple shape. In our program it is used to narrow down the location of reflection hyperbolas to certain areas in the GPR data. In order to extract the exact location and the velocity of the hyperbolas we apply a simple Hough Transform for hyperbolas. Because the Viola-Jones Algorithm reduces the input for the computational expensive Hough Transform dramatically the detection system can also be implemented on normal field computers, so on-site application is possible. The developed detection system shows promising results and detection rates in unprocessed radargrams. In order to improve the detection results and apply the program to noisy radar images more data of different GPR systems as input for the learning algorithm is necessary.

  18. Investigating the internal structure of four Azorean Sphagnum bogs using ground-penetrating radar

    Directory of Open Access Journals (Sweden)

    D. Pereira

    2017-08-01

    Full Text Available This study evaluates the applicability of ground penetrating radar (GPR as a technique for determining the thickness and internal structure of four peat deposits on Terceira Island (Azores archipelago, mid-Atlantic region. The peatlands studied are all Sphagnum mires located above 500 m a.s.l., but they differ hydrogenetically and in their degree of naturalness. Radargrams for all four bogs, obtained using both 100 MHz and 500 MHz GPR antennae, are presented and compared. The radargram data were validated against peat characteristics (bulk density, von Post H, US method obtained by direct sampling (‘open cores’ across the whole peat profile at each site. A scheme of ‘soft scoring’ for degree of naturalness (DN of the peatland was developed and used as an additional validation factor. The GPR data were positively correlated with DN, and relationships between GPR data, peat bulk density and degree of humification (H were also found. From the radargrams it was possible to distinguish the interface between the peat and the mineral substratum as well as some of the internal structure of the peat deposit, and thus to derive the total thickness of the peat deposit and (in some cases the thicknesses of its constituent layers. The first evaluation of the propagation velocity of electromagnetic waves in Azorean peat yielded a value of 0.04 m ns-1 for 100 MHz and 500 MHz radar antennae. For one of the study sites, the GPR data were analysed using GIS software to produce tridimensional models and thus to estimate the volumes of peat layers. This type of analysis has potential utility for quantifying some of the ecosystem services provided by peatlands.

  19. Knitted radar absorbing materials (RAM) based on nickel–cobalt magnetic materials

    International Nuclear Information System (INIS)

    Teber, Ahmet; Unver, Ibrahim; Kavas, Huseyin; Aktas, Bekir; Bansal, Rajeev

    2016-01-01

    There has been a long-standing interest in the development of flexible, lightweight, thin, and reconfigurable radar absorbing materials (RAM) for military applications such as camouflaging ground-based hardware against airborne radar observation. The use of polymeric Polyacrylonitrile (PAN) fabrics as a host matrix for magnetic metal nano-particles (either at the yarn-stage or after weaving the fabric) for shielding and absorbing applications has been described in the literature. In our experimental investigation, the relative concentrations of Nickel and Cobalt as well as the coating time are varied with a view to optimizing the microwave absorption characteristics of the resulting PAN-based composite material in the radar-frequency bands (X, K_u, and K). It is found that the PAN samples with the shortest coating time have the best return losses (under −20 dB return loss over a moderate bandwidth). - Graphical abstract: Here, we added the graphical abstract that provides summary the contents of the article in a concise pictorial form. - Highlights: • Flexible lightweight, thin, reconfigurable radar absorbing materials are proposed. • Polyacrylonitrile (PAN) fabrics are coated with nickel, cobalt magnetic materials. • The coating times affects microwave constitutive parameters and absorption. • Microwave absorption measurements were done via transmission line technique. • Microwave absorption is due to dielectric losses rather than magnetic losses.

  20. Knitted radar absorbing materials (RAM) based on nickel–cobalt magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Teber, Ahmet, E-mail: aht10003@engr.uconn.edu [Department of Electrical and Computer Engineering, University of Connecticut, Storrs, CT 06269 (United States); Unver, Ibrahim, E-mail: iunver@gtu.edu.tr [Department of Physics, Gebze Technical University, Kocaeli 41400 (Turkey); Kavas, Huseyin, E-mail: huseyin.kavas@medeniyet.edu.tr [Department of Physics, Istanbul Medeniyet University, Istanbul 34000 (Turkey); Aktas, Bekir, E-mail: aktas@gtu.edu.tr [Department of Physics, Gebze Technical University, Kocaeli 41400 (Turkey); Bansal, Rajeev, E-mail: rajeev@engr.uconn.edu [Department of Electrical and Computer Engineering, University of Connecticut, Storrs, CT 06269 (United States)

    2016-05-15

    There has been a long-standing interest in the development of flexible, lightweight, thin, and reconfigurable radar absorbing materials (RAM) for military applications such as camouflaging ground-based hardware against airborne radar observation. The use of polymeric Polyacrylonitrile (PAN) fabrics as a host matrix for magnetic metal nano-particles (either at the yarn-stage or after weaving the fabric) for shielding and absorbing applications has been described in the literature. In our experimental investigation, the relative concentrations of Nickel and Cobalt as well as the coating time are varied with a view to optimizing the microwave absorption characteristics of the resulting PAN-based composite material in the radar-frequency bands (X, K{sub u}, and K). It is found that the PAN samples with the shortest coating time have the best return losses (under −20 dB return loss over a moderate bandwidth). - Graphical abstract: Here, we added the graphical abstract that provides summary the contents of the article in a concise pictorial form. - Highlights: • Flexible lightweight, thin, reconfigurable radar absorbing materials are proposed. • Polyacrylonitrile (PAN) fabrics are coated with nickel, cobalt magnetic materials. • The coating times affects microwave constitutive parameters and absorption. • Microwave absorption measurements were done via transmission line technique. • Microwave absorption is due to dielectric losses rather than magnetic losses.

  1. Radar Based Flow and Water Level Forecasting in Sewer Systems

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Rasmussen, Michael R.; Grum, M.

    2009-01-01

    This paper describes the first radar based forecast of flow and/or water level in sewer systems in Denmark. The rainfall is successfully forecasted with a lead time of 1-2 hours, and flow/levels are forecasted an additional ½-1½ hours using models describing the behaviour of the sewer system. Bot...

  2. LPI Radar Waveform Recognition Based on Time-Frequency Distribution

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2016-10-01

    Full Text Available In this paper, an automatic radar waveform recognition system in a high noise environment is proposed. Signal waveform recognition techniques are widely applied in the field of cognitive radio, spectrum management and radar applications, etc. We devise a system to classify the modulating signals widely used in low probability of intercept (LPI radar detection systems. The radar signals are divided into eight types of classifications, including linear frequency modulation (LFM, BPSK (Barker code modulation, Costas codes and polyphase codes (comprising Frank, P1, P2, P3 and P4. The classifier is Elman neural network (ENN, and it is a supervised classification based on features extracted from the system. Through the techniques of image filtering, image opening operation, skeleton extraction, principal component analysis (PCA, image binarization algorithm and Pseudo–Zernike moments, etc., the features are extracted from the Choi–Williams time-frequency distribution (CWD image of the received data. In order to reduce the redundant features and simplify calculation, the features selection algorithm based on mutual information between classes and features vectors are applied. The superiority of the proposed classification system is demonstrated by the simulations and analysis. Simulation results show that the overall ratio of successful recognition (RSR is 94.7% at signal-to-noise ratio (SNR of −2 dB.

  3. Frozen: The Potential and Pitfalls of Ground-Penetrating Radar for Archaeology in the Alaskan Arctic

    Directory of Open Access Journals (Sweden)

    Thomas M. Urban

    2016-12-01

    Full Text Available Ground-penetrating radar (GPR offers many advantages for assessing archaeological potential in frozen and partially frozen contexts in high latitude and alpine regions. These settings pose several challenges for GPR, including extreme velocity changes at the interface of frozen and active layers, cryogenic patterns resulting in anomalies that can easily be mistaken for cultural features, and the difficulty in accessing sites and deploying equipment in remote settings. In this study we discuss some of these challenges while highlighting the potential for this method by describing recent successful investigations with GPR in the region. We draw on cases from Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Kobuk Valley National Park, and Gates of the Arctic National Park and Preserve. The sites required small aircraft accessibility with light equipment loads and minimal personnel. The substrates we investigate include coastal saturated active layer over permafrost, interior well-drained active layer over permafrost, a frozen thermo-karst lake, and an alpine ice patch. These examples demonstrate that GPR is effective at mapping semi-subterranean house remains in several contexts, including houses with no surface manifestation. GPR is also shown to be effective at mapping anomalies from the skeletal remains of a late Pleistocene mammoth frozen in ice. The potential for using GPR in ice and snow patch archaeology, an area of increasing interest with global environmental change exposing new material each year, is also demonstrated.

  4. A Review on Migration Methods in B-Scan Ground Penetrating Radar Imaging

    Directory of Open Access Journals (Sweden)

    Caner Özdemir

    2014-01-01

    Full Text Available Even though ground penetrating radar has been well studied and applied by many researchers for the last couple of decades, the focusing problem in the measured GPR images is still a challenging task. Although there are many methods offered by different scientists, there is not any complete migration/focusing method that works perfectly for all scenarios. This paper reviews the popular migration methods of the B-scan GPR imaging that have been widely accepted and applied by various researchers. The brief formulation and the algorithm steps for the hyperbolic summation, the Kirchhoff migration, the back-projection focusing, the phase-shift migration, and the ω-k migration are presented. The main aim of the paper is to evaluate and compare the migration algorithms over different focusing methods such that the reader can decide which algorithm to use for a particular application of GPR. Both the simulated and the measured examples that are used for the performance comparison of the presented algorithms are provided. Other emerging migration methods are also pointed out.

  5. High-resolution geophysical profiling using a stepped-frequency ground penetrating radar

    Energy Technology Data Exchange (ETDEWEB)

    Noon, D; Longstaff, D [The University of Queensland, (Australia)

    1996-05-01

    This paper describes the results of a ground penetrating radar (GPR) system which uses stepped-frequency waveforms to obtain high-resolution geophysical profiles. The main application for this system is the high-resolution mapping of thin coal seam structures, in order to assist surface mining operations in open-cut coal mines. The required depth of penetration is one meter which represents the maximum thickness of coal seams that are designated `thin`. A resolution of five centimeters is required to resolve the minimum thickness of coal (or shale partings) which can be economically recovered in an open-cut coal mine. For this application, a stepped-frequency GPR system has been developed, because of its ultrawide bandwidth (1 to 2 GHz) and high external loop sensitivity (155 dB). The field test results of the stepped-frequency GPR system on a concrete pavement and at two Australian open-cut coal mines are also presented. 7 refs., 5 figs.

  6. Electromagnetic Simulations of Ground-Penetrating Radar Propagation near Lunar Pits and Lava Tubes

    Science.gov (United States)

    Zimmerman, M. I.; Carter, L. M.; Farrell, W. M.; Bleacher, J. E.; Petro, N. E.

    2013-01-01

    Placing an Orion capsule at the Earth-Moon L2 point (EML2) would potentially enable telerobotic operation of a rover on the lunar surface. The Human Exploration Virtual Institute (HEVI) is proposing that rover operations be carried out near one of the recently discovered lunar pits, which may provide radiation shielding for long duration human stays as well as a cross-disciplinary, science-rich target for nearer-term telerobotic exploration. Ground penetrating radar (GPR) instrumentation included onboard a rover has the potential to reveal many details of underground geologic structures near a pit, as well as characteristics of the pit itself. In the present work we employ the full-wave electromagnetic code MEEP to simulate such GPR reflections from a lunar pit and other subsurface features including lava tubes. These simulations will feed forward to mission concepts requiring knowledge of where to hide from harmful radiation and other environmental hazards such as plama charging and extreme diurnal temperatures.

  7. Lunar ground penetrating radar: Minimizing potential data artifacts caused by signal interaction with a rover body

    Science.gov (United States)

    Angelopoulos, Michael; Redman, David; Pollard, Wayne H.; Haltigin, Timothy W.; Dietrich, Peter

    2014-11-01

    Ground-penetrating radar (GPR) is the leading geophysical candidate technology for future lunar missions aimed at mapping shallow stratigraphy (lunar materials, as well as its small size and lightweight components, make it a very attractive option from both a scientific and engineering perspective. However, the interaction between a GPR signal and the rover body is poorly understood and must be investigated prior to a space mission. In doing so, engineering and survey design strategies should be developed to enhance GPR performance in the context of the scientific question being asked. This paper explores the effects of a rover (simulated with a vertical metal plate) on GPR results for a range of heights above the surface and antenna configurations at two sites: (i) a standard GPR testing site with targets of known position, size, and material properties, and; (ii) a frozen lake for surface reflectivity experiments. Our results demonstrate that the GPR antenna configuration is a key variable dictating instrument design, with the XX polarization considered optimal for minimizing data artifact generation. These findings could thus be used to help guide design requirements for an eventual flight instrument.

  8. Interpretation of Ground Penetrating Radar data at the Hanford Site, Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Bergstrom, K.A.; Mitchell, T.H.; Kunk, J.R.

    1993-07-01

    Ground Penetrating Radar (GPR) is being used extensively during characterization and remediation of chemical and radioactive waste sites at the Hanford Site in Washington State. Time and money for GPR investigations are often not included during the planning and budgeting phase. Therefore GPR investigations must be inexpensive and quick to minimize impact on already established budgets and schedules. An approach to survey design, data collection, and interpretation has been developed which emphasizes speed and budget with minimal impact on the integrity of the interpretation or quality of the data. The following simple rules of thumb can be applied: (1) Assemble as much pre-survey information as possible, (2) Clearly define survey objectives prior to designing the survey and determine which combination of geophysical methods will best meet the objectives, (3) Continuously communicate with the client, before, during and after the investigation, (4) Only experienced GPR interpreters should acquire the field data, (5) Use real-time monitoring of the data to determine where and how much data to collect and assist in the interpretation, (6) Always ``error`` in favor of collecting too much data, (7) Surveys should have closely spaced (preferably 5 feet, no more than 10 feet), orthogonal profiles, (8) When possible, pull the antenna by hand.

  9. Interpretation of Ground Penetrating Radar data at the Hanford Site, Richland, Washington

    International Nuclear Information System (INIS)

    Bergstrom, K.A.; Mitchell, T.H.; Kunk, J.R.

    1993-07-01

    Ground Penetrating Radar (GPR) is being used extensively during characterization and remediation of chemical and radioactive waste sites at the Hanford Site in Washington State. Time and money for GPR investigations are often not included during the planning and budgeting phase. Therefore GPR investigations must be inexpensive and quick to minimize impact on already established budgets and schedules. An approach to survey design, data collection, and interpretation has been developed which emphasizes speed and budget with minimal impact on the integrity of the interpretation or quality of the data. The following simple rules of thumb can be applied: (1) Assemble as much pre-survey information as possible, (2) Clearly define survey objectives prior to designing the survey and determine which combination of geophysical methods will best meet the objectives, (3) Continuously communicate with the client, before, during and after the investigation, (4) Only experienced GPR interpreters should acquire the field data, (5) Use real-time monitoring of the data to determine where and how much data to collect and assist in the interpretation, (6) Always ''error'' in favor of collecting too much data, (7) Surveys should have closely spaced (preferably 5 feet, no more than 10 feet), orthogonal profiles, (8) When possible, pull the antenna by hand

  10. Using ground-penetrating radar and sidescan sonar to compare lake bottom geology in New England

    Science.gov (United States)

    Nesbitt, I. M.; Campbell, S. W.; Arcone, S. A.; Smith, S. M.

    2017-12-01

    Post-Laurentide Ice Sheet erosion and re-deposition has had a significant influence on the geomorphology of New England. Anthropogenic activities such as forestry, farming, and construction of infrastructure such as dams and associated lake reservoirs, has further contributed to near surface changes. Unfortunately, these surface dynamics are difficult to constrain, both in space and time. One analog that can be used to estimate erosion and deposition, lake basin sedimentation, is typically derived from lake bottom sediment core samples. Reliance on core records assumes that derived sedimentation rates are representative of the broader watershed, despite being only a single point measurement. Geophysical surveys suggest that this assumption can be highly erroneous and unrepresentative of an entire lake basin. Herein, we conducted ground-penetrating radar (GPR) and side-scan sonar (SSS) surveys of multiple lakes in Maine, New Hampshire, and Vermont which are representative of different basin types to estimate sedimentation rates since Laurentide retreat. Subsequent age constraints from cores on multiple GPR-imaged horizons could be used to refine estimates of sedimentation rate change caused by evolving physical, biological, and chemical processes that control erosion, transport, and re-deposition. This presentation will provide a summary of GPR and SSS data collection methods, assumptions and limitations, structural and surficial interpretations, and key findings from multiple lake basins in New England. Results show that GPR and SSS are efficient, cost effective, and relatively accurate tools for helping to constrain lake erosion and deposition processes.

  11. Improving buried threat detection in ground-penetrating radar with transfer learning and metadata analysis

    Science.gov (United States)

    Colwell, Kenneth A.; Torrione, Peter A.; Morton, Kenneth D.; Collins, Leslie M.

    2015-05-01

    Ground-penetrating radar (GPR) technology has proven capable of detecting buried threats. The system relies on a binary classifier that is trained to distinguish between two classes: a target class, encompassing many types of buried threats and their components; and a nontarget class, which includes false alarms from the system prescreener. Typically, the training process involves a simple partition of the data into these two classes, which allows for straightforward application of standard classifiers. However, since training data is generally collected in fully controlled environments, it includes auxiliary information about each example, such as the specific type of threat, its purpose, its components, and its depth. Examples from the same specific or general type may be expected to exhibit similarities in their GPR data, whereas examples from different types may differ greatly. This research aims to leverage this additional information to improve overall classification performance by fusing classifier concepts for multiple groups, and to investigate whether structure in this information can be further utilized for transfer learning, such that the amount of expensive training data necessary to learn a new, previously-unseen target type may be reduced. Methods for accomplishing these goals are presented with results from a dataset containing a variety of target types.

  12. Global measures of ionospheric electrodynamic activity inferred from combined incoherent scatter radar and ground magnetometer observations

    International Nuclear Information System (INIS)

    Richmond, A.D.; Kamide, Y.; Akasofu, S.I.; Alcayde, D.; Blanc, M.; De LaBeaujardiere, O.; Evans, D.S.; Foster, J.C.; Holt, J.M.; Friis-Christensen, E.; Pellinen, R.J.; Senior, C.; Zaitzev, A.N.

    1990-01-01

    An analysis of several global measures of high-latitude ionospheric electrodynamic activity is undertakn on the basis of results obtained from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure applied to incoherent scatter radar and ground magnetometer observatons for January 18-19, 1984. Different global measures of electric potentials, currents, resistances, and energy transfer from the magnetosphere show temporal variations that are generally well correlated. The authors present parameterizations of thees quantities in terms of the AE index and the hemispheric power index of precipitating auroral particles. It is shown how error estimates of the mapped electric fields can be used to correct the estimation of Joule heating. Global measures of potential drop, field-aligned current, and Joule heating as obtained by the AMIE procedure are compared with similar measures presented in previous studies. Agreement is found to within the uncertainties inherent in each study. The mean potential drop through which field-aligned currents flow in closing through the ionosphere is approximately 28% of the total polar cap potential drop under all conditions during these 2 days. They note that order-of-magnitude differences can appear when comparing different global measures of total electric current flow and of effective resistances of the global circuit, so that care must be exercised in choosing characteristic values of these parameters for circuit-analogy studies of ionosphere-magnetosphere electrodynamic coupling

  13. Monitoring soil moisture dynamics via ground-penetrating radar survey of agriculture fields after irrigation

    Science.gov (United States)

    Muro, G.

    2015-12-01

    It is possible to examine the quality of ground-penetrating radar (GPR) as a measure of soil moisture content in the shallow vadose zone, where roots are most abundant and water conservation best management practices are critical in active agricultural fields. By analyzing temporal samplings of 100 Mhz reflection profiles and common-midpoint (CMP) soundings over a full growing season, the variability of vertical soil moisture distribution directly after irrigation events are characterized throughout the lifecycle of a production crop. Reflection profiles produce high-resolution travel time data and summed results of CMP sounding data provide sampling depth estimates for the weak, but coherent reflections amid strong point scatterers. The high ratio of clay in the soil limits the resolution of downward propagation of infiltrating moisture after irrigation; synthetic data analysis compared against soil moisture lysimeter logs throughout the profile allow identification of the discrete soil moisture content variation in the measured GPR data. The nature of short duration irrigation events, evapotranspiration, and drainage behavior in relation to root depths observed in the GPR temporal data allow further examination and comparison with the variable saturation model HYDRUS-1D. After retrieving soil hydraulic properties derived from laboratory measured soil samples and simplified assumptions about boundary conditions, the project aims to achieve good agreement between simulated and measured soil moisture profiles without the need for excessive model calibration for GPR-derived soil moisture estimates in an agricultural setting.

  14. Monitoring underground water leakage pattern by ground penetrating radar (GPR) using 800 MHz antenna frequency

    Science.gov (United States)

    Amran, T. S. T.; Ismail, M. P.; Ahmad, M. R.; Amin, M. S. M.; Ismail, M. A.; Sani, S.; Masenwat, N. A.; Basri, N. S. M.

    2018-01-01

    Water is the most treasure natural resources, however, a huge amount of water are lost during its distribution that leads to water leakage problem. The leaks meant the waste of money and created more economic loss to treat and fix the damaged pipe. Researchers and engineers have put tremendous attempts and effort, to solve the water leakage problem especially in water leakage of buried pipeline. An advanced technology of ground penetrating radar (GPR) has been established as one of the non-destructive testing (NDT) method to detect the underground water pipe leaking. This paper focuses on the ability of GPR in water utility field especially on detection of water leaks in the underground pipeline distribution. A series of laboratory experiments were carried out using 800-MHz antenna, where the performance of GPR on detecting underground pipeline and locating water leakage was investigated and validated. A prototype to recreate water-leaking system was constructed using a 4-inch PVC pipe. Different diameter of holes, i.e. ¼ inch, ½ inch, and ¾ inch, were drilled into the pipe to simulate the water leaking. The PVC pipe was buried at the depth of 60 cm into the test bed that was filled with dry sand. 15 litres of water was injected into the PVC pipe. The water leakage patterns in term of radargram data were gathered. The effectiveness of the GPR in locating the underground water leakage was ascertained, after the results were collected and verified.

  15. Detection of underground water distribution piping system and leakages using ground penetrating radar (GPR)

    Science.gov (United States)

    Amran, Tengku Sarah Tengku; Ismail, Mohamad Pauzi; Ahmad, Mohamad Ridzuan; Amin, Mohamad Syafiq Mohd; Sani, Suhairy; Masenwat, Noor Azreen; Ismail, Mohd Azmi; Hamid, Shu-Hazri Abdul

    2017-01-01

    A water pipe is any pipe or tubes designed to transport and deliver water or treated drinking with appropriate quality, quantity and pressure to consumers. The varieties include large diameter main pipes, which supply entire towns, smaller branch lines that supply a street or group of buildings or small diameter pipes located within individual buildings. This distribution system (underground) is used to describe collectively the facilities used to supply water from its source to the point of usage. Therefore, a leaking in the underground water distribution piping system increases the likelihood of safe water leaving the source or treatment facility becoming contaminated before reaching the consumer. Most importantly, leaking can result in wastage of water which is precious natural resources. Furthermore, they create substantial damage to the transportation system and structure within urban and suburban environments. This paper presents a study on the possibility of using ground penetrating radar (GPR) with frequency of 1GHz to detect pipes and leakages in underground water distribution piping system. Series of laboratory experiment was designed to investigate the capability and efficiency of GPR in detecting underground pipes (metal and PVC) and water leakages. The data was divided into two parts: 1. detecting/locating underground water pipe, 2. detecting leakage of underground water pipe. Despite its simplicity, the attained data is proved to generate a satisfactory result indicating GPR is capable and efficient, in which it is able to detect the underground pipe and presence of leak of the underground pipe.

  16. Subsurface Investigation using 2D Resistivity and Ground Penetrating Radar at Teluk Kumbar, Penang

    Science.gov (United States)

    Teoh, YJ; Bruka, MA; Idris, NM; Ismail, NA; Muztaza, NM

    2018-04-01

    The objective of this study is to determine the structure and condition of the subsurface by using 2D resistivity and Ground Penetrating Radar (GPR) methods. The study was conducted at SK Sungai Batu, Teluk Kumbar, Penang Island. For 2D resistivity method, Wenner-Schlumberger array was used while for GPR, 250 MHz antenna was used at the site. The survey consists of 200m length survey line. GPR result shows that there is high intensity of EM. 2D resistivity result shows that the low resistivity region (200 Ωm to 340 Ωm) appears to be at the centre of the survey line from depth 7 m to 13 m. Meanwhile, the higher resistivity region (4000 Ωm to 6000 Ωm) may indicate the bedrock structure of the subsurface, which is the granitic rock. This region is bedrock which rested at depth 14 m and below. In conclusion, data obtained from GPR and 2D resistivity methods can be easily correlated to determine the features of the subsurface.

  17. 3D Ground Penetrating Radar to Detect Tree Roots and Estimate Root Biomass in the Field

    Directory of Open Access Journals (Sweden)

    Shiping Zhu

    2014-06-01

    Full Text Available The objectives of this study were to detect coarse tree root and to estimate root biomass in the field by using an advanced 3D Ground Penetrating Radar (3D GPR system. This study obtained full-resolution 3D imaging results of tree root system using 500 MHz and 800 MHz bow-tie antennas, respectively. The measurement site included two larch trees, and one of them was excavated after GPR measurements. In this paper, a searching algorithm, based on the continuity of pixel intensity along the root in 3D space, is proposed, and two coarse roots whose diameters are more than 5 cm were detected and delineated correctly. Based on the detection results and the measured root biomass, a linear regression model is proposed to estimate the total root biomass in different depth ranges, and the total error was less than 10%. Additionally, based on the detected root samples, a new index named “magnitude width” is proposed to estimate the root diameter that has good correlation with root diameter compared with other common GPR indexes. This index also provides direct measurement of the root diameter with 13%–16% error, providing reasonable and practical root diameter estimation especially in the field.

  18. Imaging of Archaeological Remains at Barcombe Roman Villa using Microwave Tomographic Depictions of Ground Penetrating Radar Data

    Science.gov (United States)

    Soldovieri, F.; Utsi, E.; Alani, A.; Persico, R.

    2012-04-01

    The site of the Barcombe Romano-British villa lies in a field on the perimeter of Barcombe village in East Sussex, England. The site came to the attention of the Mid Sussex Field Archaeological Team (MSFAT) and the University College London Field Archaeological Unit (UCL, subsequently replaced by the Centre for Continuing Education of the University of Sussex, CCE) because it was in danger of disappearing altogether without being adequately recorded [1]. In common with many other UK sites of the period, the villa had been extensively robbed out in the centuries following its demise in order to provide building material for the adjacent village and its associated farms, a common problem with Romano-British sites in the UK [2]. In addition, the site is positioned on the ridge of a field in agricultural use and has therefore been extensively ploughed out. As a result, the archaeological evidence was sparse and the little that remained was being rapidly eroded. In April 2001, a Ground Penetrating Radar (GPR) survey was carried out jointly by the Department of Engineering, Portsmouth and Utsi Electronics Ltd on behalf of the archaeological team in order to investigate the possibility of mapping both the villa and earlier prehistoric remains on the same ridge. Using a 40m by 60m grid laid out by the archaeological team, a Groundvue 1, with antennas of central frequency 400MHz, was used to survey along a series of parallel transects at intervals of 50cm. The sampling interval along the line of survey was 5cm and probing was carried out to 40ns. The results of the GPR survey, including a comparison with the evidence from the resistivity work, were published in 2002 [3]. The original GPR data were processed (using the ReflexW package) by applying background removal, adding time based gain, averaging over 2 traces in order to reduce noise resulting from the relative movement of the antennas across the ploughed field and finally applying a Bandpass Butterworth filter of 200

  19. Array-Based Ultrawideband through-Wall Radar: Prediction and Assessment of Real Radar Abilities

    Directory of Open Access Journals (Sweden)

    Nadia Maaref

    2013-01-01

    Full Text Available This paper deals with a new through-the-wall (TTW radar demonstrator for the detection and the localisation of people in a room (in a noncooperative way with the radar situated outside but in the vicinity of the first wall. After modelling the propagation through various walls and quantifying the backscattering by the human body, an analysis of the technical considerations which aims at defining the radar design is presented. Finally, an ultrawideband (UWB frequency modulated continuous wave (FMCW radar is proposed, designed, and implemented. Some representative trials show that this radar is able to localise and track moving people behind a wall in real time.

  20. Radar-Based Depth Area Reduction Factors for Colorado

    Science.gov (United States)

    Curtis, D. C.; Humphrey, J. H.; Bare, D.

    2011-12-01

    More than 340,000 fifteen-minute storm cells, nearly 45,000 one-hour cells, and over 20,000 three-hour cells found in 21 months of gage adjusted radar-rainfall estimates (GARR) over El Paso County, CO, were identified and evaluated using TITAN (Thunderstorm Identification, Tracking, Analysis and Nowcasting) software. TITAN's storm cell identification capability enabled the analysis of the geometric properties of storms, time step by time step. The gage-adjusted radar-rainfall data set was derived for months containing runoff producing events observed in the Fountain Creek Watershed within El Paso County from 1994-2008. Storm centered Depth Area Reduction Factors (DARFs) were computed and compared to DARFs published by the U.S. National Weather Service (NWS) in Technical Paper 29, which are widely used in stormwater infrastructure design. Radar-based storm centered DARFs decay much more sharply than the NWS standard curves. The results suggest lower watershed average rainfall inputs from radar-based storm centered DARFs than from standard NWS DARFs for a given watershed area. The results also suggest that DARFs are variable by return period and, perhaps, by location. Both findings could have significant impacts on design storm standards. Lower design volumes for a given return period translate to lower capacity requirements and lower cost infrastructure. Conversely, the higher volume requirements implied for the NWS DARFs translate to higher capacity requirements, higher costs, but lower risk of failure. Ultimately, a decision about which approach is to use depends on the risk tolerance of the decision maker. However, the growing volume of historical radar rainfall estimates coupled with the type of analysis described herein, supports a better understanding of risk and more informed decision-making by local officials.

  1. Ice thickness profile surveying with ground penetrating radar at Artesonraju Glacier, Peru

    Science.gov (United States)

    Chisolm, Rachel; Rabatel, Antoine; McKinney, Daene; Condom, Thomas; Cochacin, Alejo; Davila Roller, Luzmilla

    2014-05-01

    Tropical glaciers are an essential component of the water resource systems in the mountainous regions where they are located, and a warming climate has resulted in the accelerated retreat of Andean glaciers in recent decades. The shrinkage of Andean glaciers influences the flood risk for communities living downstream as new glacial lakes have begun to form at the termini of some glaciers. As these lakes continue to grow in area and volume, they pose an increasing risk of glacial lake outburst floods (GLOFs). Ice thickness measurements have been a key missing link in studying the tropical glaciers in Peru and how climate change is likely to impact glacial melt and the growth of glacial lakes. Ground penetrating radar (GPR) has rarely been applied to glaciers in Peru to measure ice thickness, and these measurements can tell us a lot about how a warming climate will affect glaciers in terms of thickness changes. In the upper Paron Valley (Cordillera Blanca, Peru), an emerging lake has begun to form at the terminus of the Artesonraju Glacier, and this lake has key features, including overhanging ice and loose rock likely to create slides, that could trigger a catastrophic GLOF if the lake continues to grow. Because the glacier mass balance and lake mass balance are closely linked, ice thickness measurements and measurements of the bed slope of the Artesonraju Glacier and underlying bedrock can give us an idea of how the lake is likely to evolve in the coming decades. This study presents GPR data taken in July 2013 at the Artesonraju Glacier as part of a collaboration between the Unidad de Glaciologia y Recursos Hidricos (UGRH) of Peru, the Institut de Recherche pour le Développement (IRD) of France and the University of Texas at Austin (UT) of the United States of America. Two different GPR units belonging to UGRH and UT were used for subsurface imaging to create ice thickness profiles and to characterize the total volume of ice in the glacier. A common midpoint

  2. Graphene based tunable fractal Hilbert curve array broadband radar absorbing screen for radar cross section reduction

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xianjun, E-mail: xianjun.huang@manchester.ac.uk [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Hu, Zhirun [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); Liu, Peiguo [College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2014-11-15

    This paper proposes a new type of graphene based tunable radar absorbing screen. The absorbing screen consists of Hilbert curve metal strip array and chemical vapour deposition (CVD) graphene sheet. The graphene based screen is not only tunable when the chemical potential of the graphene changes, but also has broadband effective absorption. The absorption bandwidth is from 8.9GHz to 18.1GHz, ie., relative bandwidth of more than 68%, at chemical potential of 0eV, which is significantly wider than that if the graphene sheet had not been employed. As the chemical potential varies from 0 to 0.4eV, the central frequency of the screen can be tuned from 13.5GHz to 19.0GHz. In the proposed structure, Hilbert curve metal strip array was designed to provide multiple narrow band resonances, whereas the graphene sheet directly underneath the metal strip array provides tunability and averagely required surface resistance so to significantly extend the screen operation bandwidth by providing broadband impedance matching and absorption. In addition, the thickness of the screen has been optimized to achieve nearly the minimum thickness limitation for a nonmagnetic absorber. The working principle of this absorbing screen is studied in details, and performance under various incident angles is presented. This work extends applications of graphene into tunable microwave radar cross section (RCS) reduction applications.

  3. Graphene based tunable fractal Hilbert curve array broadband radar absorbing screen for radar cross section reduction

    International Nuclear Information System (INIS)

    Huang, Xianjun; Hu, Zhirun; Liu, Peiguo

    2014-01-01

    This paper proposes a new type of graphene based tunable radar absorbing screen. The absorbing screen consists of Hilbert curve metal strip array and chemical vapour deposition (CVD) graphene sheet. The graphene based screen is not only tunable when the chemical potential of the graphene changes, but also has broadband effective absorption. The absorption bandwidth is from 8.9GHz to 18.1GHz, ie., relative bandwidth of more than 68%, at chemical potential of 0eV, which is significantly wider than that if the graphene sheet had not been employed. As the chemical potential varies from 0 to 0.4eV, the central frequency of the screen can be tuned from 13.5GHz to 19.0GHz. In the proposed structure, Hilbert curve metal strip array was designed to provide multiple narrow band resonances, whereas the graphene sheet directly underneath the metal strip array provides tunability and averagely required surface resistance so to significantly extend the screen operation bandwidth by providing broadband impedance matching and absorption. In addition, the thickness of the screen has been optimized to achieve nearly the minimum thickness limitation for a nonmagnetic absorber. The working principle of this absorbing screen is studied in details, and performance under various incident angles is presented. This work extends applications of graphene into tunable microwave radar cross section (RCS) reduction applications

  4. FrFT-CSWSF: Estimating cross-range velocities of ground moving targets using multistatic synthetic aperture radar

    Directory of Open Access Journals (Sweden)

    Li Chenlei

    2014-10-01

    Full Text Available Estimating cross-range velocity is a challenging task for space-borne synthetic aperture radar (SAR, which is important for ground moving target indication (GMTI. Because the velocity of a target is very small compared with that of the satellite, it is difficult to correctly estimate it using a conventional monostatic platform algorithm. To overcome this problem, a novel method employing multistatic SAR is presented in this letter. The proposed hybrid method, which is based on an extended space-time model (ESTIM of the azimuth signal, has two steps: first, a set of finite impulse response (FIR filter banks based on a fractional Fourier transform (FrFT is used to separate multiple targets within a range gate; second, a cross-correlation spectrum weighted subspace fitting (CSWSF algorithm is applied to each of the separated signals in order to estimate their respective parameters. As verified through computer simulation with the constellations of Cartwheel, Pendulum and Helix, this proposed time-frequency-subspace method effectively improves the estimation precision of the cross-range velocities of multiple targets.

  5. Logarithmic Laplacian Prior Based Bayesian Inverse Synthetic Aperture Radar Imaging.

    Science.gov (United States)

    Zhang, Shuanghui; Liu, Yongxiang; Li, Xiang; Bi, Guoan

    2016-04-28

    This paper presents a novel Inverse Synthetic Aperture Radar Imaging (ISAR) algorithm based on a new sparse prior, known as the logarithmic Laplacian prior. The newly proposed logarithmic Laplacian prior has a narrower main lobe with higher tail values than the Laplacian prior, which helps to achieve performance improvement on sparse representation. The logarithmic Laplacian prior is used for ISAR imaging within the Bayesian framework to achieve better focused radar image. In the proposed method of ISAR imaging, the phase errors are jointly estimated based on the minimum entropy criterion to accomplish autofocusing. The maximum a posterior (MAP) estimation and the maximum likelihood estimation (MLE) are utilized to estimate the model parameters to avoid manually tuning process. Additionally, the fast Fourier Transform (FFT) and Hadamard product are used to minimize the required computational efficiency. Experimental results based on both simulated and measured data validate that the proposed algorithm outperforms the traditional sparse ISAR imaging algorithms in terms of resolution improvement and noise suppression.

  6. Developing an Efficient and Cost Effective Ground-Penetrating Radar Field Methodology for Subsurface Exploration and Mapping of Cultural Resources on Public Lands

    National Research Council Canada - National Science Library

    Conyers, Lawrence B

    2006-01-01

    .... A new, emerging technology is the use of ground penetrating radar (GPR). However, in using this device due to the number of variables that can impact energy penetration and resolution, researchers are often not guaranteed a successful survey...

  7. Estimation of soil hydraulic parameters in the field by integrated hydrogeophysical inversion of time-lapse ground-penetrating radar data

    KAUST Repository

    Jadoon, Khan; Weihermü ller, Lutz; Scharnagl, Benedikt; Kowalsky, Michael B.; Bechtold, Michel; Hubbard, Susan S.; Vereecken, Harry; Lambot, Sé bastien

    2012-01-01

    An integrated hydrogeophysical inversion approach was used to remotely infer the unsaturated soil hydraulic parameters from time-lapse ground-penetrating radar (GPR) data collected at a fixed location over a bare agricultural field. The GPR model

  8. Evaluating a Radar-Based, Non Contact Streamflow Measurement System in the San Joaquin River at Vernalis, California

    Science.gov (United States)

    Cheng, Ralph T.; Gartner, Jeffrey W.; Mason, Jr., Robert R.; Costa, John E.; Plant, William J.; Spicer, Kurt R.; Haeni, F. Peter; Melcher, Nick B.; Keller, William C.; Hayes, Ken

    2004-01-01

    Accurate measurement of flow in the San Joaquin River at Vernalis, California, is vital to a wide range of Federal and State agencies, environmental interests, and water contractors. The U.S. Geological Survey uses a conventional stage-discharge rating technique to determine flows at Vernalis. Since the flood of January 1997, the channel has scoured and filled as much as 20 feet in some sections near the measurement site resulting in an unstable stage-discharge rating. In response to recent advances in measurement techniques and the need for more accurate measurement methods, the Geological Survey has undertaken a technology demonstration project to develop and deploy a radar-based streamflow measuring system on the bank of the San Joaquin River at Vernalis, California. The proposed flow-measurement system consists of a ground-penetrating radar system for mapping channel geometries, a microwave radar system for measuring surface velocities, and other necessary infrastructure. Cross-section information derived from ground penetrating radar provided depths similar to those measured by other instruments during the study. Likewise, surface-velocity patterns and magnitudes measured by the pulsed Doppler radar system are consistent with near surface current measurements derived from acoustic velocity instruments. Since the ratio of surface velocity to mean velocity falls to within a small range of theoretical value, using surface velocity as an index velocity to compute river discharge is feasable. Ultimately, the non-contact radar system may be used to make continuous, near-real-time flow measurements during high and medium flows. This report documents the data collected between April 14, 2002 and May 17, 2002 for the purposes of testing this radar based system. Further analyses of the data collected during this field effort will lead to further development and improvement of the system.

  9. Ground-Penetrating-Radar Profiles of Interior Alaska Highways: Interpretation of Stratified Fill, Frost Depths, Water Table, and Thaw Settlement over Ice-Rich Permafrost

    Science.gov (United States)

    2016-08-01

    along either massive ice surfaces or within sections of segregated ice. The uninsulated ice surface at Tok in Figure 17B is irregular. All of the...ER D C/ CR RE L TR -1 6- 14 ERDC’s Center-Directed Research Program Ground -Penetrating-Radar Profiles of Interior Alaska Highways...August 2016 Ground -Penetrating-Radar Profiles of Interior Alaska Highways Interpretation of Stratified Fill, Frost Depths, Water Table, and Thaw

  10. Application of Coupled-Wave Wentzel-Kramers-Brillouin Approximation to Ground Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Igor Prokopovich

    2017-12-01

    Full Text Available This paper deals with bistatic subsurface probing of a horizontally layered dielectric half-space by means of ultra-wideband electromagnetic waves. In particular, the main objective of this work is to present a new method for the solution of the two-dimensional back-scattering problem arising when a pulsed electromagnetic signal impinges on a non-uniform dielectric half-space; this scenario is of interest for ground penetrating radar (GPR applications. For the analytical description of the signal generated by the interaction of the emitted pulse with the environment, we developed and implemented a novel time-domain version of the coupled-wave Wentzel-Kramers-Brillouin approximation. We compared our solution with finite-difference time-domain (FDTD results, achieving a very good agreement. We then applied the proposed technique to two case studies: in particular, our method was employed for the post-processing of experimental radargrams collected on Lake Chebarkul, in Russia, and for the simulation of GPR probing of the Moon surface, to detect smooth gradients of the dielectric permittivity in lunar regolith. The main conclusions resulting from our study are that our semi-analytical method is accurate, radically accelerates calculations compared to simpler mathematical formulations with a mostly numerical nature (such as the FDTD technique, and can be effectively used to aid the interpretation of GPR data. The method is capable to correctly predict the protracted return signals originated by smooth transition layers of the subsurface dielectric medium. The accuracy and numerical efficiency of our computational approach make promising its further development.

  11. Current uses of ground penetrating radar in groundwater-dependent ecosystems research.

    Science.gov (United States)

    Paz, Catarina; Alcalá, Francisco J; Carvalho, Jorge M; Ribeiro, Luís

    2017-10-01

    Ground penetrating radar (GPR) is a high-resolution technique widely used in shallow groundwater prospecting. This makes GPR ideal to characterize the hydrogeological functioning of groundwater-dependent ecosystems (GDE). This paper reviews current uses of GPR in GDE research through the construction of a database comprising 91 worldwide GPR case studies selected from the literature and classified according to (1) geological environments favouring GDE; (2) hydrogeological research interests; and (3) field technical and (4) hydrogeological conditions of the survey. The database analysis showed that inland alluvial, colluvial, and glacial formations were the most widely covered geological environments. Water-table depth was the most repeated research interest. By contrast, weathered-marl and crystalline-rock environments as well as the delineation of salinity interfaces in coastal and inland areas were less studied. Despite that shallow groundwater propitiated GDE in almost all the GPR case studies compiled, only one case expressly addressed GDE research. Common ranges of prospecting depth, water-table depth, and volumetric water content deduced by GPR and other techniques were identified. Antenna frequency of 100MHz and the common offset acquisition technique predominated in the database. Most of GPR case studies were in 30-50° N temperate latitudes, mainly in Europe and North America. Eight original radargrams were selected from several GPR profiles performed in 2014 and 2015 to document database classes and identified gaps, as well as to define experimental ranges of operability in GDE environments. The results contribute to the design of proper GPR surveys in GDE research. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Adapting Ground Penetrating Radar for Non-Destructive In-Situ Root and Tuber Assessment

    Science.gov (United States)

    Teare, B. L.; Hays, D. B.; Delgado, A.; Dobreva, I. D.; Bishop, M. P.; Lacey, R.; Huo, D.; Wang, X.

    2017-12-01

    Ground penetrating radar (GPR) is a rapidly evolving technology extensively used in geoscience, civil science, archeology, and military, and has become a novel application in agricultural systems. One promising application of GPR is for root and tuber detection and measurement. Current commercial GPR systems have been used for detection of large roots, but few studies have attempted to detect agronomic roots, and even fewer have attempted to measure and quantify the total root mass. The ability to monitor and measure root and tuber mass and architecture in an agricultural setting would have far-reaching effects. A few of these include the potential for breeding higher yielding root and tuber crops, rapid bulking roots, discovery of crops with greater carbon sequestration, discovery of plant varieties which have greater ability to stabilize slopes against erosion and slope failure, and drought tolerant varieties. Despite the possible benefits and the current maturity of GPR technology, several challenges remain in the attempt to optimize its use for root and tuber detection. These challenges center on three categories: spatial resolution, data processing, and field-deployable hardware configuration. This study is centered around tuber measurement and its objectives are to i) identify ideal antenna array configurations, frequency, and pulse density; ii) develop novel processing techniques which leverage powerful computer technologies to provide highly accurate measurements of detected features; and iii) develop a cart system which is appropriate for agricultural fields and non-destructive sampling. Already, a 2 GHz multiarray antenna has been identified as an optimal system for tuber detection. Software and processing algorithm development is ongoing, but has already shown improvement over current software offerings. Recent field activity suggest that carts should be width adjustable and sport independent suspension systems to maintain antenna orientation.

  13. Near-surface Imaging of a Maya Plaza Complex using Ground-Penetrating Radar

    Science.gov (United States)

    Aitken, J. A.; Stewart, R. R.

    2005-05-01

    The University of Calgary has conducted a number of ground-penetrating radar surveys at a Maya archaeological site. The purpose of the study is to discern the near-surface structure and stratigraphy of the plaza, and to assist the archaeologists in focusing their excavation efforts. The area of study is located in Belize, Central America at the ancient Maya site of Maax Na. Flanked by structures believed to be temples to the north and west, the archaeologists were interested in determining how many levels of plaza were built and if there was any discernable slope to the plaza. Over the last three years, both 2-D lines and 3-D grids were acquired at the plaza using a Sensors and Software Inc. Noggin Plus system at an antenna frequency of 250 MHz. The processing flow consisted of the application of gain, various filtering techniques and a diffraction stack migration using Reflexw. Interpolation of the gridded data was investigated using simple averaging, F-K migration, pre-stack migration and inversion techniques. As this study has evolved over different field seasons, measured velocities appear to change with the saturation level of the shallow section. Velocity measurements ranged from 0.058 - .106 m/ns during the wet conditions encountered in 2002 and 2004, while velocities of 1.22 - 1.40 m/ns were measured in the drought of 2003. The GPR images to date indicate continuous and interpretable images of the subsurface, showing evidence of structure, discontinuities and amplitude variations. A number of interesting anomalies have been identified, and prioritized for excavation.

  14. Ground penetrating radar and microwave tomography for the safety management of a cultural heritage site: Miletos Ilyas Bey Mosque (Turkey)

    International Nuclear Information System (INIS)

    Kadioglu, Selma; Kadioglu, Yusuf Kagan; Catapano, Ilaria; Soldovieri, Francesco

    2013-01-01

    Detection and assessment of structural damage affecting foundation robustness is of significant relevance for the safety management of cultural heritage sites. In this framework, ground penetrating radar (GPR) is worth consideration owing to its capability of providing high resolution and detailed information about the inner status of a structure, without involving significant invasive actions and ensuring a fast survey. On the other hand, the effectiveness of a GPR diagnostic survey can be impaired by the low interpretability of the raw data radargrams; thus huge interest is currently focused on the development of advanced and application-oriented data processing strategies. In this paper, a data processing chain based on the combined use of the commercial REFLEXW program and a microwave tomography approach is presented. An assessment of the achievable imaging capabilities is provided by processing measurements collected during a survey at the Great Mosque of Ilyas Bey (Ilyas Bey Mosque), one of the most important cultural heritages in ancient Miletos-Iona in Söke-Aydin city (Turkey). (paper)

  15. 3D visualization of integrated ground penetrating radar data and EM-61 data to determine buried objects and their characteristics

    International Nuclear Information System (INIS)

    Kadioğlu, Selma; Daniels, Jeffrey J

    2008-01-01

    This paper is based on an interactive three-dimensional (3D) visualization of two-dimensional (2D) ground penetrating radar (GPR) data and their integration with electromagnetic induction (EMI) using EM-61 data in a 3D volume. This method was used to locate and identify near-surface buried old industrial remains with shape, depth and type (metallic/non-metallic) in a brownfield site. The aim of the study is to illustrate a new approach to integrating two data sets in a 3D image for monitoring and interpretation of buried remains, and this paper methodically indicates the appropriate amplitude–colour and opacity function constructions to activate buried remains in a transparent 3D view. The results showed that the interactive interpretation of the integrated 3D visualization was done using generated transparent 3D sub-blocks of the GPR data set that highlighted individual anomalies in true locations. Colour assignments and formulating of opacity of the data sets were the keys to the integrated 3D visualization and interpretation. This new visualization provided an optimum visual comparison and an interpretation of the complex data sets to identify and differentiate the metallic and non-metallic remains and to control the true interpretation on exact locations with depth. Therefore, the integrated 3D visualization of two data sets allowed more successful identification of the buried remains

  16. Radar Target Recognition Based on Stacked Denoising Sparse Autoencoder

    Directory of Open Access Journals (Sweden)

    Zhao Feixiang

    2017-04-01

    Full Text Available Feature extraction is a key step in radar target recognition. The quality of the extracted features determines the performance of target recognition. However, obtaining the deep nature of the data is difficult using the traditional method. The autoencoder can learn features by making use of data and can obtain feature expressions at different levels of data. To eliminate the influence of noise, the method of radar target recognition based on stacked denoising sparse autoencoder is proposed in this paper. This method can extract features directly and efficiently by setting different hidden layers and numbers of iterations. Experimental results show that the proposed method is superior to the K-nearest neighbor method and the traditional stacked autoencoder.

  17. Radar-based collision avoidance for unmanned surface vehicles

    Science.gov (United States)

    Zhuang, Jia-yuan; Zhang, Lei; Zhao, Shi-qi; Cao, Jian; Wang, Bo; Sun, Han-bing

    2016-12-01

    Unmanned surface vehicles (USVs) have become a focus of research because of their extensive applications. To ensure safety and reliability and to perform complex tasks autonomously, USVs are required to possess accurate perception of the environment and effective collision avoidance capabilities. To achieve these, investigation into realtime marine radar target detection and autonomous collision avoidance technologies is required, aiming at solving the problems of noise jamming, uneven brightness, target loss, and blind areas in marine radar images. These technologies should also satisfy the requirements of real-time and reliability related to high navigation speeds of USVs. Therefore, this study developed an embedded collision avoidance system based on the marine radar, investigated a highly real-time target detection method which contains adaptive smoothing algorithm and robust segmentation algorithm, developed a stable and reliable dynamic local environment model to ensure the safety of USV navigation, and constructed a collision avoidance algorithm based on velocity obstacle (V-obstacle) which adjusts the USV's heading and speed in real-time. Sea trials results in multi-obstacle avoidance firstly demonstrate the effectiveness and efficiency of the proposed avoidance system, and then verify its great adaptability and relative stability when a USV sailing in a real and complex marine environment. The obtained results will improve the intelligent level of USV and guarantee the safety of USV independent sailing.

  18. GPM GROUND VALIDATION ENVIRONMENT CANADA (EC) MICRO RAIN RADAR (MRR) GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — Environment Canada (EC) collected data from the Micro Rain Radar (MRR) during the GPM Cold-season Precipitation Experiment (GCPEx) in Ontario, Canada during the...

  19. Ground-penetrating radar study of the Cena Bog, Latvia: linkage of reflections with peat moisture content

    Directory of Open Access Journals (Sweden)

    Karušs, J.

    2015-12-01

    Full Text Available Present work illustrates results of the ground-penetrating radar (GPR study of the Cena Bog, Latvia. Six sub-horizontal reflections that most probably correspond to boundaries between sediments with different electromagnetic properties were identified. One of the reflections corresponds to bog peat mineral bottom interface but the rest are linked to boundaries within the peat body. The radar profiles are incorporated with sediment cores and studies of peat moisture and ash content, and degree of decomposition. Most of the electromagnetic wave reflections are related to changes in peat moisture content. The obtained data show that peat moisture content changes of at least 3 % are required to cause GPR signal reflection. However, there exist reflections that do not correlate with peat moisture content. As a result, authors disagree with a dominant opinion that all reflections in bogs are solely due to changes in volumetric peat moisture content.

  20. Delineating shallow Neogene deformation structures in northeastern Pará State using Ground Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Dilce F. Rossetti

    2003-06-01

    Full Text Available The geological characterization of shallow subsurface Neogene deposits in northeastern Pará State using Ground Penetrating Radar (GPR revealed normal and reverse faults, as well as folds, not yet well documented by field studies. The faults are identified mostly by steeply-dipping reflections that sharply cut the nearby reflections causing bed offsets, drags and rollovers. The folds are recognized by reflections that are highly undulating, configuring broad concave and convex-up features that are up to 50 m wide and 80 to 90 ns deep. These deformation structures are mostly developed within deposits of Miocene age, though some of the faults might continue into younger deposits as well. Although the studied GPR sections show several diffractions caused by trees, differential degrees of moisture, and underground artifacts, the structures recorded here can not be explained by any of these ''noises''. The detailed analysis of the GPR sections reveals that they are attributed to bed distortion caused by brittle deformation and folding. The record of faults and folds are not widespread in the Neogene deposits of the Bragantina area. These GPR data are in agreement with structural models, which have proposed a complex evolution including strike-slip motion for this area from the Miocene to present.A caracterização geológica de depósitos neógenos ocorrentes em sub-superfície rasa no nordeste do Estado do Pará, usando Radar de Penetração no Solo (GPR, revelou a presença de falhas normais e reversas, bem como dobras, ainda não documentadas em estudos de campo prévios. As falhas são identificadas por reflexões inclinadas que cortam bruscamente reflexões vizinhas, causando freqüentes deslocamentos de camadas. As dobras são reconhecidas por reflexões fortemente ondulantes, configurando feições côncavas e convexas que medem até 50 m de amplitude e 80 a 90 m de profundidade. Estas estruturas deformacionais desenvolvem-se, principalmente

  1. Radar-Derived Quantitative Precipitation Estimation Based on Precipitation Classification

    Directory of Open Access Journals (Sweden)

    Lili Yang

    2016-01-01

    Full Text Available A method for improving radar-derived quantitative precipitation estimation is proposed. Tropical vertical profiles of reflectivity (VPRs are first determined from multiple VPRs. Upon identifying a tropical VPR, the event can be further classified as either tropical-stratiform or tropical-convective rainfall by a fuzzy logic (FL algorithm. Based on the precipitation-type fields, the reflectivity values are converted into rainfall rate using a Z-R relationship. In order to evaluate the performance of this rainfall classification scheme, three experiments were conducted using three months of data and two study cases. In Experiment I, the Weather Surveillance Radar-1988 Doppler (WSR-88D default Z-R relationship was applied. In Experiment II, the precipitation regime was separated into convective and stratiform rainfall using the FL algorithm, and corresponding Z-R relationships were used. In Experiment III, the precipitation regime was separated into convective, stratiform, and tropical rainfall, and the corresponding Z-R relationships were applied. The results show that the rainfall rates obtained from all three experiments match closely with the gauge observations, although Experiment II could solve the underestimation, when compared to Experiment I. Experiment III significantly reduced this underestimation and generated the most accurate radar estimates of rain rate among the three experiments.

  2. Detection of Ground Clutter from Weather Radar Using a Dual-Polarization and Dual-Scan Method

    Directory of Open Access Journals (Sweden)

    Mohammad-Hossein Golbon-Haghighi

    2016-06-01

    Full Text Available A novel dual-polarization and dual-scan (DPDS classification algorithm is developed for clutter detection in weather radar observations. Two consecutive scans of dual-polarization radar echoes are jointly processed to estimate auto- and cross-correlation functions. Discriminants are then defined and estimated in order to separate clutter from weather based on their physical and statistical properties. An optimal Bayesian classifier is used to make a decision on clutter presence from the estimated discriminant functions. The DPDS algorithm is applied to the data collected with the KOUN polarimetric radar and compared with the existing detection methods. It is shown that the DPDS algorithm yields a higher probability of detection and lower false alarm rate in clutter detection.

  3. Mapping Fractures in KAERI Underground Research Tunnel using Ground Penetrating Radar

    Science.gov (United States)

    Baek, Seung-Ho; Kim, Seung-Sep; Kwon, Jang-Soon

    2016-04-01

    The proportion of nuclear power in the Republic of Korea occupies about 40 percent of the entire electricity production. Processing or disposing nuclear wastes, however, remains one of biggest social issues. Although low- and intermediate-level nuclear wastes are stored temporarily inside nuclear power plants, these temporary storages can last only up to 2020. Among various proposed methods for nuclear waste disposal, a long-term storage using geologic disposal facilities appears to be most highly feasible. Geological disposal of nuclear wastes requires a nuclear waste repository situated deep within a stable geologic environment. However, the presence of small-scale fractures in bedrocks can cause serious damage to durability of such disposal facilities because fractures can become efficient pathways for underground waters and radioactive wastes. Thus, it is important to find and characterize multi-scale fractures in bedrocks hosting geologic disposal facilities. In this study, we aim to map small-scale fractures inside the KAERI Underground Research Tunnel (KURT) using ground penetrating radar (GPR). The KURT is situated in the Korea Atomic Energy Research Institute (KAERI). The survey target is a section of wall cut by a diamond grinder, which preserves diverse geologic features such as dykes. We conducted grid surveys on the wall using 500 MHz and 1000 MHz pulseEKKO PRO sensors. The observed GPR signals in both frequencies show strong reflections, which are consistent to form sloping planes. We interpret such planar features as fractures present in the wall. Such fractures were also mapped visually during the development of the KURT. We confirmed their continuity into the wall from the 3D GPR images. In addition, the spatial distribution and connectivity of these fractures are identified from 3D subsurface images. Thus, we can utilize GPR to detect multi-scale fractures in bedrocks, during and after developing underground disposal facilities. This study was

  4. Ground movement analysis in the north of Belgium by radar interferometry

    International Nuclear Information System (INIS)

    Declercq, Pierre-Yves; Devleeschouwer, Xavier; Brassinnes, Stephane

    2012-01-01

    interest by the Persistent Scatterer Radar Interferometry technique. In parallel, Mol and Doel were specifically processed to extract as much PS as possible from the SAR images to increase the resolution and the quality of the interpretation around the two RD and D reference sites. This technique is indeed able to measure millimetric ground deformation over large area (>100 km 2 ) on a raw from satellite images. In the case such ground motion would be identified, it is of major importance to find the origin and the magnitude of the on-going processes. Considering the geological setting of the area and related human activities, numerous processes could be envisaged (e.g., tectonic activity related to the Roer valley graben and its faults system, groundwater (over)exploitation, recent sediments compaction, landfills, former coal mines areas, etc...). The first processing was carried out over 68 ERS1/2 images covering the years 1992-2001 and 67 ENVISAT images spanning the years 2003-2010. The usual time period between each satellite image acquisition is 35 days. The total number of PS for ERS and ENVISAT is respectively 320,734 and 145,052 over the entire studied area, the PS density reached usually more than 200 PS/km 2 in urbanised area and dropped to less than 20 PS/km 2 in rural zone. Several localized and specific ground motions are detected in the ROI. The western border of the Kempen coal basin faced a negative vertical movement (-16 mm/year max) during the time span of ERS 1/2 images. The vertical ground movement monitored with the ENVISAT images shows an inversion of the velocities since 2003 with positive velocities (maximal annual mean velocity values of +10 mm/year ). The movements are related to the ground water extraction during the exploitation of the coal mines generating subsidence and to the recharge of the mine aquifer after the closure exploitations in 1992 facilitating the uplift of the region. In the vicinity of Mol, the PS data shows that this region is

  5. Informing hydrological models with ground-based time-lapse relative gravimetry: potential and limitations

    DEFF Research Database (Denmark)

    Bauer-Gottwein, Peter; Christiansen, Lars; Rosbjerg, Dan

    2011-01-01

    parameter uncertainty decreased significantly when TLRG data was included in the inversion. The forced infiltration experiment caused changes in unsaturated zone storage, which were monitored using TLRG and ground-penetrating radar. A numerical unsaturated zone model was subsequently conditioned on both......Coupled hydrogeophysical inversion emerges as an attractive option to improve the calibration and predictive capability of hydrological models. Recently, ground-based time-lapse relative gravity (TLRG) measurements have attracted increasing interest because there is a direct relationship between...

  6. German Radar Observation Shuttle Experiment (ROSE)

    Science.gov (United States)

    Sleber, A. J.; Hartl, P.; Haydn, R.; Hildebrandt, G.; Konecny, G.; Muehlfeld, R.

    1984-01-01

    The success of radar sensors in several different application areas of interest depends on the knowledge of the backscatter of radar waves from the targets of interest, the variance of these interaction mechanisms with respect to changing measurement parameters, and the determination of the influence of he measuring systems on the results. The incidence-angle dependency of the radar cross section of different natural targets is derived. Problems involved by the combination of data gained with different sensors, e.g., MSS-, TM-, SPOTand SAR-images are analyzed. Radar cross-section values gained with ground-based radar spectrometers and spaceborne radar imaging, and non-imaging scatterometers and spaceborne radar images from the same areal target are correlated. The penetration of L-band radar waves into vegetated and nonvegetated surfaces is analyzed.

  7. Ground Penetrating Radar investigation of depositional architecture: the São Sebastião and Marizal formations in the Cretaceous Tucano Basin (Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Larissa Natsumi Tamura

    Full Text Available ABSTRACT: One key factor for the advance in the study of fluvial deposits is the application of geophysical methods, being the Ground Penetrating Radar one of special value. Although applied to active rivers, the method is not extensively tested on the rock record, bearing interest for hydrocarbon reservoir analogue models. The São Sebastião and Marizal formations were the subject of previous studies, which made possible the comparison of Ground Penetrating Radar survey to previous stratigraphic studies in order to identify the best combination of resolution, penetration and antenna frequency for the studied subject. Eight radar facies were identified, being six of them related to fluvial sedimentary environments, one related to eolian sedimentary environment and one radar facies interpreted as coastal sedimentary environment. The Ground Penetrating Radar data showed compatibility to sedimentary structures in the outcrops, like planar and trough cross-stratified beds. It is noted that the obtained resolution was efficient in the identification of structures up to 0.3 m using a 100 MHz antenna. In this way, the Ground Penetrating Radar survey in outcrops bears great potential for further works on fluvial depositional architecture.

  8. Ground penetrating radar and microwave tomography 3D applications for the deck evaluation of the Musmeci bridge in Potenza, Italy

    International Nuclear Information System (INIS)

    Bavusi, Massimo; Loperte, Antonio; Lapenna, Vincenzo; Soldovieri, Francesco; Di Napoli, Rosario; Di Cesare, Antonio; Carlo Ponzo, Felice

    2011-01-01

    An extensive experimental and numerical investigation has been carried out to assess the status of the 'Ponte sul Basento' (1967–1976), in the town of Potenza (Basilicata region, southern Italy), better known as the Musmeci bridge. Architecturally, the bridge is a considerable reinforced 20th century concrete structure that was designed and built by the Italian architect Sergio Musmeci (1926–1981). Moreover, the bridge represents an important element of the infrastructural network, linking the city centre to the Potenza-Sicignano highway, crossing the Basento river and the railway close to the main train station of the city. Recently, due to ageing and continuous and significant traffic, the bridge started to be affected by several problems such as water infiltration. Within the presented study, a widespread ground penetrating radar (GPR) survey has been designed to investigate the geometrical characteristics of the bridge deck (Gerber saddles, internal stiffening walls, pillar supports) and detect the presence of defects or damage due to water infiltration and traffic fatigue. Concerning this, a 900 MHz 3D GPR survey has been performed along a zone of one of the lanes on the road surface. Moreover, a second 1500 MHz 3D survey has been carried out at the bottom of the bridge deck in order to gain detailed information about an important structural element of the bridge, the Gerber saddle. Both results have been processed following two approaches: the first a classical time-domain processing session based on commercial software and the use of migration; the second in microwave tomography, an advanced frequency domain automatic PC-based inversion algorithm. In this paper, we present a comparative interpretation of both kinds of processed results, and provide considerations about the investigated structures

  9. Material Property Estimation for Direct Detection of DNAPL using Integrated Ground-Penetrating Radar Velocity, Imaging and Attribute Analysis

    Energy Technology Data Exchange (ETDEWEB)

    John H. Bradford; Stephen Holbrook; Scott B. Smithson

    2004-12-09

    The focus of this project is direct detection of DNAPL's specifically chlorinated solvents, via material property estimation from multi-fold surface ground-penetrating radar (GPR) data. We combine state-of-the-art GPR processing methodology with quantitative attribute analysis and material property estimation to determine the location and extent of residual and/or pooled DNAPL in both the vadose and saturated zones. An important byproduct of our research is state-of-the-art imaging which allows us to pinpoint attribute anomalies, characterize stratigraphy, identify fracture zones, and locate buried objects.

  10. Proceedings of the Government Users Workshop on Ground Penetrating Radar Applications and Equipment 26-27 March 1992 Vicksburg, Mississippi

    Science.gov (United States)

    1992-12-01

    Allison P.O. Box 946 USDA Tifton , GA 31794 Box 946 Phone: 912-386-3899 Tifton , GA 31794 FAX: 912-386-7215 Phone: 912-386-7075 FAX: 912-386-7215 Paul...FAX: 603-889-3984 FAX: 071-724-1433 Ricky Fletcher S. V. Cosvay USDA-ARS-SEWRL Sensors and Software, Inc. Rt. 4, Box 1390 5566 Tomken Road Tifton , GA ... Tifton , GA 31793 Phone: 305-634-4507 Phone: 912-386-7174 FAX: 305-635-4901 FAX: 912-386-7215 8 GOVERNMENT USERS WORKSHOP ON GROUND PENETRATING RADAR

  11. Three-dimensional ground penetrating radar imaging using multi-frequency diffraction tomography

    Energy Technology Data Exchange (ETDEWEB)

    Mast, J.E.; Johansson, E.M. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    In this talk we present results from a three-dimensional image reconstruction algorithm for impulse radar operating in monostatic pule-echo mode. The application of interest to us is the nondestructive evaluation of civil structures such as bridge decks. We use a multi-frequency diffraction tomography imaging technique in which coherent backward propagations of the received reflected wavefield form a spatial image of the scattering interfaces within the region of interest. This imaging technique provides high-resolution range and azimuthal visualization of the subsurface region. We incorporate the ability to image in planarly layered conductive media and apply the algorithm to experimental data from an offset radar system in which the radar antenna is not directly coupled to the surface of the region. We present a rendering in three-dimensions of the resulting image data which provides high-detail visualization.

  12. NOAA Next Generation Radar (NEXRAD) Level 2 Base Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of Level II weather radar data collected from Next-Generation Radar (NEXRAD) stations located in the contiguous United States, Alaska, Hawaii,...

  13. Joint application of Geoelectrical Resistivity and Ground Penetrating Radar techniques for the study of hyper-saturated zones. Case study in Egypt

    Directory of Open Access Journals (Sweden)

    Hany S. Mesbah

    2017-06-01

    Full Text Available This paper presents the results of the application of the Geoelectrical Resistivity Sounding (GRS and Ground Penetrating Radar (GPR for outlining and investigating of surface springing out (flow of groundwater to the base of an service building site, and determining the reason(s for the zone of maximum degree of saturation; in addition to provide stratigraphic information for this site. The studied economic building is constructed lower than the ground surface by about 7 m. A Vertical Electrical Sounding (VES survey was performed at 12 points around the studied building in order to investigate the vertical and lateral extent of the subsurface sequence, three VES's were conducted at each side of the building at discrete distances. And a total of 9 GPR profiles with 100- and 200-MHz antennae were conducted, with the objective of evaluating the depth and the degree of saturation of the subsurface layers. The qualitative and quantitative interpretation of the acquired VES's showed easily the levels of saturations close to and around the studied building. From the interpretation of GPR profiles, it was possible to locate and determine the saturated layers. The radar signals are penetrated and enabled the identification of the subsurface reflectors. The results of GPR and VES showed a good agreement and the integrated interpretations were supported by local geology. Finally, the new constructed geoelectrical resistivity cross-sections (in contoured-form, are easily clarifying the direction of groundwater flow toward the studied building.

  14. Preliminary results of sequential monitoring of simulated clandestine graves in Colombia, South America, using ground penetrating radar and botany.

    Science.gov (United States)

    Molina, Carlos Martin; Pringle, Jamie K; Saumett, Miguel; Hernández, Orlando

    2015-03-01

    In most Latin American countries there are significant numbers of missing people and forced disappearances, 68,000 alone currently in Colombia. Successful detection of shallow buried human remains by forensic search teams is difficult in varying terrain and climates. This research has created three simulated clandestine burial styles at two different depths commonly encountered in Latin America to gain knowledge of optimum forensic geophysics detection techniques. Repeated monitoring of the graves post-burial was undertaken by ground penetrating radar. Radar survey 2D profile results show reasonable detection of ½ clothed pig cadavers up to 19 weeks of burial, with decreasing confidence after this time. Simulated burials using skeletonized human remains were not able to be imaged after 19 weeks of burial, with beheaded and burnt human remains not being able to be detected throughout the survey period. Horizontal radar time slices showed good early results up to 19 weeks of burial as more area was covered and bi-directional surveys were collected, but these decreased in amplitude over time. Deeper burials were all harder to image than shallower ones. Analysis of excavated soil found soil moisture content almost double compared to those reported from temperate climate studies. Vegetation variations over the simulated graves were also noted which would provide promising indicators for grave detection. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Remote sensing of high-latitude ionization profiles by ground-based and spaceborne instrumentation

    International Nuclear Information System (INIS)

    Vondrak, R.R.

    1981-01-01

    Ionospheric specification and modeling are now largely based on data provided by active remote sensing with radiowave techniques (ionosondes, incoherent-scatter radars, and satellite beacons). More recently, passive remote sensing techniques have been developed that can be used to monitor quantitatively the spatial distribution of high-latitude E-region ionization. These passive methods depend on the measurement, or inference, of the energy distribution of precipitating kilovolt electrons, the principal source of the nighttime E-region at high latitudes. To validate these techniques, coordinated measurements of the auroral ionosphere have been made with the Chatanika incoherent-scatter radar and a variety of ground-based and spaceborne sensors

  16. Ground penetrating radar geologic field studies of the ejecta of Barringer Meteorite Crater, Arizona, as a planetary analog

    Science.gov (United States)

    Russell, Patrick S.; Grant, John A.; Williams, Kevin K.; Carter, Lynn M.; Brent Garry, W.; Daubar, Ingrid J.

    2013-09-01

    penetrating radar (GPR) has been a useful geophysical tool in investigating a variety of shallow subsurface geological environments on Earth. Here we investigate the capabilities of GPR to provide useful geologic information in one of the most common geologic settings of planetary surfaces, impact crater ejecta. Three types of ejecta are surveyed with GPR at two wavelengths (400 MHz, 200 MHz) at Meteor Crater, Arizona, with the goal of capturing the GPR signature of the subsurface rock population. In order to "ground truth" the GPR characterization, subsurface rocks are visually counted and measured in preexisting subsurface exposures immediately adjacent to and below the GPR transect. The rock size-frequency distribution from 10 to 50 cm based on visual counts is well described by both power law and exponential functions, the former slightly better, reflecting the control of fragmentation processes during the impact-ejection event. GPR counts are found to overestimate the number of subsurface rocks in the upper meter (by a factor of 2-3x) and underestimate in the second meter of depth (0.6-1.0x), results attributable to the highly scattering nature of blocky ejecta. Overturned ejecta that is fractured yet in which fragments are minimally displaced from their complement fragments produces fewer GPR returns than well-mixed ejecta. The use of two wavelengths and division of results into multiple depth zones provides multiple aspects by which to characterize the ejecta block population. Remote GPR measurement of subsurface ejecta in future planetary situations with no subsurface exposure can be used to characterize those rock populations relative to that of Meteor Crater.

  17. Exploration of the Moon with Remote Sensing, Ground-Penetrating Radar, and the Regolith-Evolved Gas Analyzer (REGA)

    Science.gov (United States)

    Cooper, B. L.; Hoffman, J. H.; Allen, Carlton C.; McKay, David S.

    1998-01-01

    There are two important reasons to explore the Moon. First, we would like to know more about the Moon itself: its history, its geology, its chemistry, and its diversity. Second, we would like to apply this knowledge to a useful purpose. namely finding and using lunar resources. As a result of the recent Clementine and Lunar Prospector missions, we now have global data on the regional surface mineralogy of the Moon, and we have good reason to believe that water exists in the lunar polar regions. However, there is still very little information about the subsurface. If we wish to go to the lunar polar regions to extract water, or if we wish to go anywhere else on the Moon and extract (or learn) anything at all, we need information in three dimensions an understanding of what lies below the surface, both shallow and deep. The terrestrial mining industry provides an example of the logical steps that lead to an understanding of where resources are located and their economic significance. Surface maps are examined to determine likely locations for detailed study. Geochemical soil sample surveys, using broad or narrow grid patterns, are then used to gather additional data. Next, a detailed surface map is developed for a selected area, along with an interpretation of the subsurface structure that would give rise to the observed features. After that, further sampling and geophysical exploration are used to validate and refine the original interpretation, as well as to make further exploration/ mining decisions. Integrating remotely sensed, geophysical, and sample datasets gives the maximum likelihood of a correct interpretation of the subsurface geology and surface morphology. Apollo-era geophysical and automated sampling experiments sought to look beyond the upper few microns of the lunar surface. These experiments, including ground-penetrating radar and spectrometry, proved the usefulness of these methods for determining the best sites for lunar bases and lunar mining

  18. An investigation of recent storm histories using Ground Penetrating Radar at Bay-Bay Spit, Bicol, Central Philippines

    Science.gov (United States)

    Switzer, Adam D.; Pile, Jeremy; Soria, Janneli Lea A.; Siringan, Fernando; Daag, Arturo; Brill, Dominik

    2016-04-01

    The Philippine archipelago lies in the path of seasonal tropical cyclones, and much of the coast is prone to periodic inundation and overwash during storm surges. On example is typhoon Durian a category 3 storm that made landfall on the 30th November 2006, in Bicol province, on the east central Philippine coast. Satellite imagery from May 2007 reveal that Durian breached a sandy spit that runs southeast from the mouth of the Quinale River at Bay-Bay village towards Tabaco City. The imagery also showed that, although the breach site showed signs of partial recovery, geomorphological evidence of the inundation event associated with typhoon Durian still remains. In 2012 we mapped the geomorphological features of Durian. In June 2013 we returned to conduct Ground Penetrating Radar (GPR) surveys on the Bay-Bay spit to investigate potential subsurface evidence of previous storm events. The GPR surveys comprised five, 1.5 km, longshore profiles and 12 cross-shore profiles, of 50 m - 200 m in length. The GPR system used for this study was a Sensors and Software Noggin with 100 Mhz antennas. Near surface velocities were determine using Hyperbolae matching in order to estimate depth. Topographic and positional data were collected using a dGPS system. After minimal processing depth of penetration during the survey varied from 2 - 8 m. The cross-shore GPR profiles reveal at least two erosional events prior to 2006 typhoon Durian, with approximately 10 m of recovery and progradation between each erosion surface. The GPR profiles that captured the erosional features were revisited in September 2013 for trial pitting, stratigraphic description, and sediment sampling. Sediment cores were taken horizontally from the trench walls and vertically from the trench bases to date sediments using Optically Stimulated Luminescence (OSL), which eventually could constrain the timing of the erosional surfaces.

  19. Improving Weather Radar Precipitation Estimates by Combining two Types of Radars

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ellerbæk; Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2014-01-01

    This paper presents a demonstration of how Local Area Weather Radar (LAWR) X-band measurements can be combined with meteorological C–band measurements into a single radar product. For this purpose, a blending method has been developed which combines the strengths of the two radar systems. Combining...... the two radar types achieves a radar product with both long range and high temporal resolution. It is validated that the blended radar product performs better than the individual radars based on ground observations from laser disdrometers. However, the data combination is challenged by lower performance...... of the LAWR. Although both radars benefits from the data combination, it is also found that advection based temporal interpolation is a more favourable method for increasing the temporal resolution of meteorological C–band measurements....

  20. Logarithmic Laplacian Prior Based Bayesian Inverse Synthetic Aperture Radar Imaging

    Directory of Open Access Journals (Sweden)

    Shuanghui Zhang

    2016-04-01

    Full Text Available This paper presents a novel Inverse Synthetic Aperture Radar Imaging (ISAR algorithm based on a new sparse prior, known as the logarithmic Laplacian prior. The newly proposed logarithmic Laplacian prior has a narrower main lobe with higher tail values than the Laplacian prior, which helps to achieve performance improvement on sparse representation. The logarithmic Laplacian prior is used for ISAR imaging within the Bayesian framework to achieve better focused radar image. In the proposed method of ISAR imaging, the phase errors are jointly estimated based on the minimum entropy criterion to accomplish autofocusing. The maximum a posterior (MAP estimation and the maximum likelihood estimation (MLE are utilized to estimate the model parameters to avoid manually tuning process. Additionally, the fast Fourier Transform (FFT and Hadamard product are used to minimize the required computational efficiency. Experimental results based on both simulated and measured data validate that the proposed algorithm outperforms the traditional sparse ISAR imaging algorithms in terms of resolution improvement and noise suppression.

  1. An Integration of Ground-Penetrating Radar, Remote Sensing, and Discharge Records of the Modern Kicking Horse River, BC

    Science.gov (United States)

    Cyples, N.; Ielpi, A.; Dirszowsky, R.

    2017-12-01

    The Kicking Horse River is a gravel-bed stream originating from glacial meltwater supplied by the Wapta Icefields in south-eastern British Columbia. An alluvial tract extends for 7 km through Field, BC, where the trunk channel undergoes diurnal and seasonal fluctuations in flow as a result of varying glacial-meltwater supply and runoff recharge. Prior studies erected the Kicking Horse River as a reference for proximal braided systems, and documented bar formation and sediment distribution patterns from ground observations. However, a consistent model of planform evolution and related stratigraphic signature is lacking. Specific objectives of this study are to examine the morphodynamic evolution and stratigraphic signature of channel-bar complexes using high-resolution satellite imagery, sedimentologic and discharge observations, and ground-penetrating radar (GPR). Remote sensing highlights rates of lateral channel migration of as much as 270 meters over eight years ( 34 meters/year), and demonstrates how flood stages are associated with stepwise episodes of channel braiding and anabranching. GPR analysis aided in the identification of five distinct radar facies, including: discontinuous, inclined, planar, trough-shaped, and mounded reflectors, which were respectively related to specific architectural elements and fluvial processes responsible for bar evolution. Across-stream GPR transects demonstrated higher heterogeneity in facies distribution, while downstream-oriented transects yielded a more monotonous distribution in radar facies. Notably, large-scale inclined reflectors related to step-wise bar accretion are depicted only in downstream-oriented transects, while discontinuous reflectors related to bedform stacking appear to be dominant in along-stream transects. Integration of sedimentological data with remote sensing, gauging records, and GPR analysis allows for high-resolution modelling of stepwise changes in alluvial morphology. Conceptual models stemming

  2. Ground-based observations of exoplanet atmospheres

    NARCIS (Netherlands)

    Mooij, Ernst Johan Walter de

    2011-01-01

    This thesis focuses on the properties of exoplanet atmospheres. The results for ground-based near-infrared secondary eclipse observations of three different exoplanets, TrES-3b, HAT-P-1b and WASP-33b, are presented which have been obtained with ground-based telescopes as part of the GROUSE project.

  3. Multi-offset ground-penetrating radar imaging of a lab-scale infiltration test

    Directory of Open Access Journals (Sweden)

    A. R. Mangel

    2012-11-01

    Full Text Available A lab scale infiltration experiment was conducted in a sand tank to evaluate the use of time-lapse multi-offset ground-penetrating radar (GPR data for monitoring dynamic hydrologic events in the vadose zone. Sets of 21 GPR traces at offsets between 0.44–0.9 m were recorded every 30 s during a 3 h infiltration experiment to produce a data cube that can be viewed as multi-offset gathers at unique times or common offset images, tracking changes in arrivals through time. Specifically, we investigated whether this data can be used to estimate changes in average soil water content during wetting and drying and to track the migration of the wetting front during an infiltration event. For the first problem we found that normal-moveout (NMO analysis of the GPR reflection from the bottom of the sand layer provided water content estimates ranging between 0.10–0.30 volumetric water content, which underestimated the value determined by depth averaging a vertical array of six moisture probes by 0.03–0.05 volumetric water content. Relative errors in the estimated depth to the bottom of the 0.6 m thick sand layer were typically on the order of 2%, though increased as high as 25% as the wetting front approached the bottom of the tank. NMO analysis of the wetting front reflection during the infiltration event generally underestimated the depth of the front with discrepancies between GPR and moisture probe estimates approaching 0.15 m. The analysis also resulted in underestimates of water content in the wetted zone on the order of 0.06 volumetric water content and a wetting front velocity equal to about half the rate inferred from the probe measurements. In a parallel modeling effort we found that HYDRUS-1D also underestimates the observed average tank water content determined from the probes by approximately 0.01–0.03 volumetric water content, despite the fact that the model was calibrated to the probe data. This error suggests that the assumed conceptual

  4. Subarray-based FDA radar to counteract deceptive ECM signals

    Science.gov (United States)

    Abdalla, Ahmed; Wang, Wen-Qin; Yuan, Zhao; Mohamed, Suhad; Bin, Tang

    2016-12-01

    In recent years, the frequency diverse array (FDA) radar concept has attracted extensive attention, as it may benefit from a small frequency increment, compared to the carrier frequency across the array elements and thereby achieve an array factor that is a function of the angle, the time, and the range which is superior to the conventional phase array radar (PAR). However, limited effort on the subject of FDA in electronic countermeasure scenarios, especially in the presence of mainbeam deceptive jamming, has been published. Basic FDA is not desirable for anti-jamming applications, due to the range-angle coupling response of targets. In this paper, a novel method based on subarrayed FDA signal processing is proposed to counteract deceptive ECM signals. We divide the FDA array into multiple subarrays, each of which employs a distinct frequency increment. As a result, in the subarray-based FDA, the desired target can be distinguished at subarray level in joint range-angle-Doppler domain by utilizing the fact that the jammer generates false targets with the same ranges to each subarray without reparations. The performance assessment shows that the proposed solution is effective for deceptive ECM targets suppression. The effectiveness is verified by simulation results.

  5. Nanosecond radar system based on repetitive pulsed relativistic BWO

    International Nuclear Information System (INIS)

    Bunkin, B.V.; Gaponov-Grekhov, A.V.; Eltchaninov, A.S.; Zagulov, F.Ya.; Korovin, S.D.; Mesyats, G.A.; Osipov, M.L.; Otlivantchik, E.A.; Petelin, M.I.; Prokhorov, A.M.

    1993-01-01

    The paper presents the results of studies of a nanosecond radar system based on repetitive pulsed relativistic BWO. A pulsed power repetitive accelerator producing electron beams of electron energy 500-700 keV and current 5 kA in pulses of duraction 10 ns with a repetition rate of 100 pps is described. The results of experiments with a high-voltage gas-filled spark gap and a cold-cathode vacuum diode under the conditions of high repetition rates are given. Also presented are the results of studies of a relativistic BWO operating with a wavelength of 3 cm. It is shown that for a high-current beam electron energy of 500-700 keV, the BWO efficiency can reach 35%, the microwave power being 10 9 W. A superconducting solenoid creating a magnetic field of 30 kOe was used for the formation and transportation of the high-current electron beam. In conclusion, the outcome of tests of a nanosecond radar station based on a pulsed power repetitive accelerator and a relativistic BWO is reported

  6. Characterization of the spatial distribution of porosity in the eogenetic karst Miami Limestone using ground penetrating radar

    Science.gov (United States)

    Mount, G. J.; Comas, X.; Wright, W. J.; McClellan, M. D.

    2014-12-01

    Hydrogeologic characterization of karst limestone aquifers is difficult due to the variability in the spatial distribution of porosity and dissolution features. Typical methods for aquifer investigation, such as drilling and pump testing, are limited by the scale or spatial extent of the measurement. Hydrogeophysical techniques such as ground penetrating radar (GPR) can provide indirect measurements of aquifer properties and be expanded spatially beyond typical point measures. This investigation used a multiscale approach to identify and quantify porosity distribution in the Miami Limestone, the lithostratigraphic unit that composes the uppermost portions of the Biscayne Aquifer in Miami Dade County, Florida. At the meter scale, laboratory measures of porosity and dielectric permittivity were made on blocks of Miami Limestone using zero offset GPR, laboratory and digital image techniques. Results show good correspondence between GPR and analytical porosity estimates and show variability between 22 and 66 %. GPR measurements at the field scale 10-1000 m investigated the bulk porosity of the limestone based on the assumption that a directly measured water table would remain at a consistent depth in the GPR reflection record. Porosity variability determined from the changes in the depth to water table resulted in porosity values that ranged from 33 to 61 %, with the greatest porosity variability being attributed to the presence of dissolution features. At the larger field scales, 100 - 1000 m, fitting of hyperbolic diffractions in GPR common offsets determined the vertical and horizontal variability of porosity in the saturated subsurface. Results indicate that porosity can vary between 23 and 41 %, and delineate potential areas of enhanced recharge or groundwater / surface water interactions. This study shows porosity variability in the Miami Limestone can range from 22 to 66 % within 1.5 m distances, with areas of high macroporosity or karst dissolution features

  7. Monitoring of active layer dynamics at a permafrost site on Svalbard using multi-channel ground-penetrating radar

    Directory of Open Access Journals (Sweden)

    S. Westermann

    2010-11-01

    Full Text Available Multi-channel ground-penetrating radar is used to investigate the late-summer evolution of the thaw depth and the average soil water content of the thawed active layer at a high-arctic continuous permafrost site on Svalbard, Norway. Between mid of August and mid of September 2008, five surveys have been conducted in gravelly soil over transect lengths of 130 and 175 m each. The maximum thaw depths range from 1.6 m to 2.0 m, so that they are among the deepest thaw depths recorded in sediments on Svalbard so far. The thaw depths increase by approximately 0.2 m between mid of August and beginning of September and subsequently remain constant until mid of September. The thaw rates are approximately constant over the entire length of the transects within the measurement accuracy of about 5 to 10 cm. The average volumetric soil water content of the thawed soil varies between 0.18 and 0.27 along the investigated transects. While the measurements do not show significant changes in soil water content over the first four weeks of the study, strong precipitation causes an increase in average soil water content of up to 0.04 during the last week. These values are in good agreement with evapotranspiration and precipitation rates measured in the vicinity of the the study site. While we cannot provide conclusive reasons for the detected spatial variability of the thaw depth at the study site, our measurements show that thaw depth and average soil water content are not directly correlated.

    The study demonstrates the potential of multi-channel ground-penetrating radar for mapping thaw depth in permafrost areas. The novel non-invasive technique is particularly useful when the thaw depth exceeds 1.5 m, so that it is hardly accessible by manual probing. In addition, multi-channel ground-penetrating radar holds potential for mapping the latent heat content of the active layer and for estimating weekly to monthly averages of the ground heat flux during the

  8. COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar:" ongoing research activities and mid-term results

    Science.gov (United States)

    Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Slob, Evert; Tosti, Fabio

    2015-04-01

    This work aims at presenting the ongoing activities and mid-term results of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar.' Almost three hundreds experts are participating to the Action, from 28 COST Countries (Austria, Belgium, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Malta, Macedonia, The Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom), and from Albania, Armenia, Australia, Egypt, Hong Kong, Jordan, Israel, Philippines, Russia, Rwanda, Ukraine, and United States of America. In September 2014, TU1208 has been praised among the running Actions as 'COST Success Story' ('The Cities of Tomorrow: The Challenges of Horizon 2020,' September 17-19, 2014, Torino, IT - A COST strategic workshop on the development and needs of the European cities). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Moreover, the Action is oriented to the following specific objectives and expected deliverables: (i) coordinating European scientists to highlight problems, merits and limits of current GPR systems; (ii) developing innovative protocols and guidelines, which will be published in a handbook and constitute a basis for European standards, for an effective GPR application in civil- engineering tasks; safety, economic and financial criteria will be integrated within the protocols; (iii) integrating competences for the improvement and merging of electromagnetic scattering techniques and of data- processing techniques; this will lead to a novel freeware tool for the localization of buried objects

  9. Synchronous Design and Test of Distributed Passive Radar Systems Based on Digital Broadcasting and Television

    Directory of Open Access Journals (Sweden)

    Wan Xianrong

    2017-02-01

    Full Text Available Digital broadcasting and television are important classes of illuminators of opportunity for passive radars. Distributed and multistatic structure are the development trends for passive radars. Most modern digital broadcasting and television systems work on a network, which not only provides a natural condition to distributed passive radar but also puts forward higher requirements on the design of passive radar systems. Among those requirements, precise synchronization among the receivers and transmitters as well as among multiple receiving stations, which mainly involves frequency and time synchronization, is the first to be solved. To satisfy the synchronization requirements of distributed passive radars, a synchronization scheme based on GPS is presented in this paper. Moreover, an effective scheme based on the China Mobile Multimedia Broadcasting signal is proposed to test the system synchronization performance. Finally, the reliability of the synchronization design is verified via the distributed multistatic passive radar experiments.

  10. Development of Ethernet Based Remote Monitoring and Controlling of MST Radar Transmitters using ARM Cortex Microcontroller

    Directory of Open Access Journals (Sweden)

    Lakshmi Narayana ROSHANNA

    2013-01-01

    Full Text Available The recently emerging Web Services technology has provided a new and excellent solution to Industrial Automation in online control and remote monitoring. In this paper, a Web Service Based Remote Monitoring & Controlling of Radar Transmitters for safety management (WMCT developed for MST Radar is described. It achieved the MST radar transmitters’ remote supervisory, data logging and controlling activities. The system is developed using an ARM Cortex M3 processor to monitor and control the 32 triode-based transmitters of the 53-MHz Radar. The system controls transmitters via the internet using an Ethernet client server and store health status in the Database for radar performance analysis. The system enables scientists to operate and control the radar transmitters from a remote client machine Webpage.

  11. Ground penetrating radar measurements at the ONKALO research tunnel and eastern part of the Olkiluoto investigation area at July 2006

    International Nuclear Information System (INIS)

    Sipola, V.; Tarvainen, A.-M.

    2007-04-01

    Ground Penetrating Radar (GPR) measurements were carried out at ONKALO research site in summer 2006. Measurements included 400 metres of measurements inside ONKALO access tunnel and about 1800 metres of measurements on the ground, at the eastern parts of Olkiluoto investigation area. The purpose of the measurements done inside the access tunnel was to investigate, whether it would be possible to locate deformation structures or long fractures in the rock mass below the tunnel. The purpose of the measurements made on top of the ground was to investigate, whether it would be possible to locate glacio-isostatic faults from the soils. A secondary target was to try and locate the rock surface. The chosen part of ONKALO tunnel was measured using five different frequencies, which enabled comparing the results to each other. It also enabled getting a higher resolution picture of the top rock, than what would have been possible using only one low-frequency antenna. The on-the-ground measurements were measured using only one frequency. (orig.)

  12. Wave Height Estimation from Shadowing Based on the Acquired X-Band Marine Radar Images in Coastal Area

    Directory of Open Access Journals (Sweden)

    Yanbo Wei

    2017-08-01

    Full Text Available In this paper, the retrieving significant wave height from X-band marine radar images based on shadow statistics is investigated, since the retrieving accuracy can not be seriously affected by environmental factors and the method has the advantage of without any external reference to calibrate. However, the accuracy of the significant wave height estimated from the radar image acquired at the near-shore area is not ideal. To solve this problem, the effect of water depth is considered in the theoretical derivation of estimated wave height based on the sea surface slope. And then, an improved retrieving algorithm which is suitable for both in deep water area and shallow water area is developed. In addition, the radar data are sparsely processed in advance in order to achieve high quality edge image for the requirement of shadow statistic algorithm, since the high resolution radar images will lead to angle-blurred for the image edge detection and time-consuming in the estimation of sea surface slope. The data acquired from Pingtan Test Base in Fujian Province were used to verify the effectiveness of the proposed algorithm. The experimental results demonstrate that the improved method which takes into account the water depth is more efficient and effective and has better performance for retrieving significant wave height in the shallow water area, compared to the in situ buoy data as the ground truth and that of the existing shadow statistic method.

  13. Radar equations for modern radar

    CERN Document Server

    Barton, David K

    2012-01-01

    Based on the classic Radar Range-Performance Analysis from 1980, this practical volume extends that work to ensure applicability of radar equations to the design and analysis of modern radars. This unique book helps you identify what information on the radar and its environment is needed to predict detection range. Moreover, it provides equations and data to improve the accuracy of range calculations. You find detailed information on propagation effects, methods of range calculation in environments that include clutter, jamming and thermal noise, as well as loss factors that reduce radar perfo

  14. Ground-penetrating radar exploration for ancient monuments at the Valley of Mummies -Kilo 6, Bahariya Oasis, Egypt

    Science.gov (United States)

    Shaaban, Fathy A.; Abbas, Abbas M.; Atya, Magdy A.; Hafez, Mahfouz A.

    2009-06-01

    A Valley of Mummies was discovered recently by an Egyptian team at Bahariya Oasis, located about 380 km west of the pyramids. Four tombs were excavated, and inside them were found one hundred and five mummies (105), many of them beautifully gilded. These mummies, many sumptuously decorated with religious scenes, are the very best Roman-Period mummies ever found in Egypt. These remains are around 2000 years old, but they are in remarkable condition. A Ground-Penetrating Radar (GPR) had proved successful in detecting the cavities in resistive soil in which the mummies were found. The GPR survey conducted near the earlier-discovered tombs at Kilo-6 El-Bahariya to Farafra Oasis road is the focus of this paper. The GPR survey was conducted using the SIR-2000 attached to a 200 MHz monostatic antenna. The two areas to be surveyed were selected by the archaeologists in situ. Area one was 40 m × 40 m and Area two was 30 m × 15 m. A grid pattern survey in one direction; with one-meter profile spacing was done to both areas. In addition, a focusing survey was undertaken over the entire Area one. In addition, twenty long GPR profiles were conducted in an attempt to determine the outer, expected limits of the burial area. After the data acquisition, Reflex software was used for data processing and presentation. The final results of the radar survey: in the form of 2D radar records, time slices and 3D block diagrams; were used to guide the archaeologists during the excavation process. The excavation processes have been completed by the archaeologists, and many tombs and mummies were discovered. It is worthy to mention that, the excavations and location of tombs and cavities matched strongly with the GPR results.

  15. Void detection beneath reinforced concrete sections: The practical application of ground-penetrating radar and ultrasonic techniques

    Science.gov (United States)

    Cassidy, Nigel J.; Eddies, Rod; Dods, Sam

    2011-08-01

    Ground-penetrating radar (GPR) and ultrasonic 'pulse echo' techniques are well-established methods for the imaging, investigation and analysis of steel reinforced concrete structures and are important civil engineering survey tools. GPR is, arguably, the more widely-used technique as it is suitable for a greater range of problem scenarios (i.e., from rebar mapping to moisture content determination). Ultrasonic techniques are traditionally associated with the engineering-based, non-destructive testing of concrete structures and their integrity analyses (e.g., flaw detection, shear/longitudinal velocity determination, etc). However, when used in an appropriate manner, both techniques can be considered complementary and provide a unique way of imaging the sub-surface that is suited to a range of geotechnical problems. In this paper, we present a comparative study between mid-to-high frequency GPR (450 MHz and 900 MHz) and array-based, shear wave, pulse-echo ultrasonic surveys using proprietary instruments and conventional GPR data processing and visualisation techniques. Our focus is the practical detection of sub-metre scale voids located under steel reinforced concrete sections in realistic survey conditions (e.g., a capped, relict mine shaft or vent). Representative two-dimensional (2D) sections are presented for both methods illustrating the similarities/differences in signal response and the temporal-spatial target resolutions achieved with each technique. The use of three-dimensional data volumes and time slices (or 'C-scans') for advanced interpretation is also demonstrated, which although common in GPR applications is under-utilised as a technique in general ultrasonic surveys. The results show that ultrasonic methods can perform as well as GPR for this specific investigation scenario and that they have the potential of overcoming some of the inherent limitations of GPR investigations (i.e., the need for careful antenna frequency selection and survey design in

  16. 5 year radar-based rainfall statistics: disturbances analysis and development of a post-correction scheme for the German radar composite

    Science.gov (United States)

    Wagner, A.; Seltmann, J.; Kunstmann, H.

    2015-02-01

    A radar-based rainfall statistic demands high quality data that provide realistic precipitation amounts in space and time. Instead of correcting single radar images, we developed a post-correction scheme for long-term composite radar data that corrects corrupted areas, but preserves the original precipitation patterns. The post-correction scheme is based on a 5 year statistical analysis of radar composite data and its constituents. The accumulation of radar images reveals artificial effects that are not visible in the individual radar images. Some of them are already inherent to single radar data such as the effect of increasing beam height, beam blockage or clutter remnants. More artificial effects are introduced in the process of compositing such as sharp gradients at the boundaries of overlapping areas due to different beam heights and resolution. The cause of these disturbances, their behaviour with respect to reflectivity level, season or altitude is analysed based on time-series of two radar products: the single radar reflectivity product PX for each of the 16 radar systems of the German Meteorological Service (DWD) for the time span 2000 to 2006 and the radar composite product RX of DWD from 2005 through to 2009. These statistics result in additional quality information on radar data that is not available elsewhere. The resulting robust characteristics of disturbances, e.g. the dependency of the frequencies of occurrence of radar reflectivities on beam height, are then used as a basis for the post-correction algorithm. The scheme comprises corrections for shading effects and speckles, such as clutter remnants or overfiltering, as well as for systematic differences in frequencies of occurrence of radar reflectivities between the near and the far ranges of individual radar sites. An adjustment to rain gauges is also included. Applying this correction, the Root-Mean-Square-Error for the comparison of radar derived annual rain amounts with rain gauge data

  17. Synthetic pulse radar including a microprocessor based controller

    International Nuclear Information System (INIS)

    Fowler, J.C.; Rubin, L.A.; Still, W.L.

    1980-01-01

    This invention relates to pulse radar detection of targets in extended media, including natural phenomena such as oil, coal and ore deposits within the earth. In particular, this invention relates to a pulse radar system employing a synthetic pulse formed from a fourier spectrum of frequencies generated and detected by a digitally controlled transmitter and receiver circuits

  18. The NASA Polarimetric Radar (NPOL)

    Science.gov (United States)

    Petersen, Walter A.; Wolff, David B.

    2013-01-01

    Characteristics of the NASA NPOL S-band dual-polarimetric radar are presented including its operating characteristics, field configuration, scanning capabilities and calibration approaches. Examples of precipitation science data collections conducted using various scan types, and associated products, are presented for different convective system types and previous field campaign deployments. Finally, the NASA NPOL radar location is depicted in its home base configuration within the greater Wallops Flight Facility precipitation research array supporting NASA Global Precipitation Measurement Mission ground validation.

  19. Ice volume changes (1936–1990–2007 and ground-penetrating radar studies of Ariebreen, Hornsund, Spitsbergen

    Directory of Open Access Journals (Sweden)

    Javier Lapazaran

    2013-08-01

    Full Text Available Ariebreen is a small (0.37 km2-valley glacier located in southern Spitsbergen. Our ground-penetrating radar surveys of the glacier show that it is less than 30 m thick on average, with a maximum thickness of 82 m, and it appears to be entirely cold. By analysing digital terrain models of the ice surface from different dates, we determine the area and volume changes during two periods, 1936–1990 and 1990–2007. The total ice volume of the glacier has decreased by 73% during the entire period 1936–2007, which is equivalent to a mean mass balance rate of −0.61±0.17 m y−1 w.eq. The glacier thinning rate has increased markedly between the first and second periods, from −0.50±0.22 to −0.95±0.17 m y−1 w.eq.

  20. Ground penetrating radar documents short-term near-surface hydrological changes around Old Faithful Geyser, Yellowstone National Park, USA

    Science.gov (United States)

    Lynne, Bridget Y.; Heasler, Henry; Jaworowski, Cheryl; Smith, Gary J.; Smith, Isaac J.; Foley, Duncan

    2018-04-01

    In April 2015, Ground Penetrating Radar (GPR) was used to characterize the shallow subsurface (images were collected between two eruptions of Old Faithful Geyser. Each set of time-sequence GPR recordings consisted of four transects aligned to provide coverage near the potential location of the inferred 15 m deep geyser chamber. However, the deepest penetration we could achieve with a 200 MHz GPR antennae was 5 m. Seven time-sequence events were collected over a 48-minute interval to image changes in the near-surface, during pre- and post-eruptive cycles. Time-sequence GPR images revealed a series of possible micro-fractures in a highly porous siliceous sinter in the near-surface that fill and drain repetitively, immediately after an eruption and during the recharge period prior to the next main eruptive event.

  1. Characteristics of ejecta and alluvial deposits at Meteor Crater, Arizona and Odessa Craters, Texas: Results from ground penetrating radar

    Science.gov (United States)

    Grant, J. A.; Schultz, P. H.

    1991-01-01

    Previous ground penetrating radar (GRP) studies around 50,000 year old Meteor Crater revealed the potential for rapid, inexpensive, and non-destructive sub-surface investigations for deep reflectors (generally greater than 10 m). New GRP results are summarized focusing the shallow sub-surfaces (1-2 m) around Meteor Crater and the main crater at Odessa. The following subject areas are covered: (1) the thickness, distribution, and nature of the contact between surrounding alluvial deposits and distal ejecta; and (2) stratigraphic relationships between both the ejecta and alluvium derived from both pre and post crater drainages. These results support previous conclusions indicating limited vertical lowering (less than 1 m) of the distal ejecta at Meteor Crater and allow initial assessment of the gradational state if the Odessa craters.

  2. Potential of Probing the Lunar Regolith using Rover-Mounted Ground Penetrating Radar: Moses Lake Dune Field Analog Study

    Science.gov (United States)

    Horz, F.; Heggy, E.; Fong, T.; Kring, D.; Deans, M.; Anglade, A.; Mahiouz, K.; Bualat, M.; Lee, P.; Bluethmann, W.

    2009-01-01

    Probing radars have been widely recognized by the science community to be an efficient tool to explore lunar subsurface providing a unique capability to address several scientific and operational issues. A wideband (200 to 1200 MHz) Ground Penetrating Radar (GPR) mounted on a surface rover can provide high vertical resolution and probing depth from few tens of centimeters to few tens of meters depending on the sounding frequency and the ground conductivity. This in term can provide a better understand regolith thickness, elemental iron concentration (including ilmenite), volatile presence, structural anomalies and fracturing. All those objectives are of important significance for understanding the local geology and potential sustainable resources for future landing sites in particular exploring the thickness, structural heterogeneity and potential volatiles presence in the lunar regolith. While the operation and data collection of GPR is a straightforward case for most terrestrial surveys, it is a challenging task for remote planetary study especially on robotic platforms due to the complexity of remote operation in rough terrains and the data collection constrains imposed by the mechanical motion of the rover and limitation in data transfer. Nevertheless, Rover mounted GPR can be of great support to perform systematic subsurface surveys for a given landing site as it can provide scientific and operational support in exploring subsurface resources and sample collections which can increase the efficiency of the EVA activities for potential human crews as part of the NASA Constellation Program. In this study we attempt to explore the operational challenges and their impact on the EVA scientific return for operating a rover mounted GPR in support of potential human activity on the moon. In this first field study, we mainly focused on the ability of GPR to support subsurface sample collection and explore shallow subsurface volatiles.

  3. Searching for the IRA "disappeared": ground-penetrating radar investigation of a churchyard burial site, Northern Ireland.

    Science.gov (United States)

    Ruffell, Alastair

    2005-11-01

    A search for the body of a victim of terrorist abduction and murder was made in a graveyard on the periphery of a major conurbation in Northern Ireland. The area is politically sensitive and the case of high profile. This required non-invasive, completely non-destructive and rapid assessment of the scene. A MALA RAMAC ground-penetrating radar system was used to achieve these objectives. Unprocessed and processed 400 MHz data show the presence of a collapse feature above and around a known 1970s burial with no similar collapse above the suspect location. In the saturated, clay-rich sediments of the site, 200 MHz data offered no advantage over 400 MHz data. Unprocessed 100 MHz data shows a series of multiples in the known burial with no similar features in the suspect location. Processed 100 MHz lines defined the shape of the collapse around the known burial to 2 m depth, together with the geometry of the platform (1 m depth) the gravedigger used in the 1970s to construct the site. In addition, processed 100 MHz data showed both the dielectric contrast in and internal reflection geometry of the soil imported above the known grave. Thus the sequence, geometry, difference in infill and infill direction of the grave was reconstructed 30 years after burial. The suspect site showed no evidence of shallow or deep inhumation. Subsequently, the missing person's body was found some distance from this site, vindicating the results and interpretation from ground-penetrating radar. The acquisition, processing, collapse feature and sequence stratigraphic interpretation of the known burial and empty (suspect) burial site may be useful proxies for other, similar investigations. GPR was used to evaluate this site within 3 h of the survey commencing, using unprocessed data. An additional day of processing established that the suspect body did not reside here, which was counter to police and community intelligence.

  4. Classification of radar echoes using fractal geometry

    International Nuclear Information System (INIS)

    Azzaz, Nafissa; Haddad, Boualem

    2017-01-01

    Highlights: • Implementation of two concepts of fractal geometry to classify two types of meteorological radar echoes. • A new approach, called a multi-scale fractal dimension is used for classification between fixed echoes and rain echoes. • An Automatic identification system of meteorological radar echoes was proposed using fractal geometry. - Abstract: This paper deals with the discrimination between the precipitation echoes and the ground echoes in meteorological radar images using fractal geometry. This study aims to improve the measurement of precipitations by weather radars. For this, we considered three radar sites: Bordeaux (France), Dakar (Senegal) and Me lbourne (USA). We showed that the fractal dimension based on contourlet and the fractal lacunarity are pertinent to discriminate between ground and precipitation echoes. We also demonstrated that the ground echoes have a multifractal structure but the precipitations are more homogeneous than ground echoes whatever the prevailing climate. Thereby, we developed an automatic classification system of radar using a graphic interface. This interface, based on the fractal geometry makes possible the identification of radar echoes type in real time. This system can be inserted in weather radar for the improvement of precipitation estimations.

  5. A digital beamforming processor for the joint DoD/NASA space based radar mission

    Science.gov (United States)

    Fischman, Mark A.; Le, Charles; Rosen, Paul A.

    2004-01-01

    The Space Based Radar (SBR) program includes a joint technology demonstration between NASA and the Air Force to design a low-earth orbiting, 2x50 m L-band radar system for both Earth science and intelligence related observations.

  6. Ground-penetrating radar for sedimentology: methodological advances and examples from the Usumacinta-Grijalva delta plain, Tabasco, México

    NARCIS (Netherlands)

    Van Dam, Remke; Nooren, Kees|info:eu-repo/dai/nl/33761430X; Dogan, Mine; Hoek, Wim|info:eu-repo/dai/nl/163819394

    2014-01-01

    Ground-penetrating radar (GPR) is widely used as a tool for imaging sedimentary structures and reconstructing depositional history in a range of settings. Most GPR systems use a pair of dipole antennas to transmit and receive electromagnetic energy, typically in the frequency range of 0.025-1 GHz.

  7. Imaging the Mariánské Lázně Fault (Czech Republic) by 3-D ground-penetrating radar and electric resistivity tomography

    Czech Academy of Sciences Publication Activity Database

    Fischer, Tomáš; Štěpančíková, Petra; Karousová, M.; Tábořík, P.; Flechsig, C.; Gaballah, M.

    2012-01-01

    Roč. 56, č. 4 (2012), s. 1019-1036 ISSN 0039-3169 R&D Projects: GA AV ČR IAA300120905 Institutional research plan: CEZ:AV0Z30120515; CEZ:AV0Z30460519 Keywords : fault tectonics * resistivity tomography * ground penetrating radar Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.975, year: 2012

  8. Regional frequency analysis of extreme rainfall in Belgium based on radar estimates

    Directory of Open Access Journals (Sweden)

    E. Goudenhoofdt

    2017-10-01

    Full Text Available In Belgium, only rain gauge time series have been used so far to study extreme rainfall at a given location. In this paper, the potential of a 12-year quantitative precipitation estimation (QPE from a single weather radar is evaluated. For the period 2005–2016, 1 and 24 h rainfall extremes from automatic rain gauges and collocated radar estimates are compared. The peak intensities are fitted to the exponential distribution using regression in Q-Q plots with a threshold rank which minimises the mean squared error. A basic radar product used as reference exhibits unrealistic high extremes and is not suitable for extreme value analysis. For 24 h rainfall extremes, which occur partly in winter, the radar-based QPE needs a bias correction. A few missing events are caused by the wind drift associated with convective cells and strong radar signal attenuation. Differences between radar and gauge rainfall values are caused by spatial and temporal sampling, gauge underestimations and radar errors. Nonetheless the fit to the QPE data is within the confidence interval of the gauge fit, which remains large due to the short study period. A regional frequency analysis for 1 h duration is performed at the locations of four gauges with 1965–2008 records using the spatially independent QPE data in a circle of 20 km. The confidence interval of the radar fit, which is small due to the sample size, contains the gauge fit for the two closest stations from the radar. In Brussels, the radar extremes are significantly higher than the gauge rainfall extremes, but similar to those observed by an automatic gauge during the same period. The extreme statistics exhibit slight variations related to topography. The radar-based extreme value analysis can be extended to other durations.

  9. Ground Penetrating Radar Investigations in the Noble Hall of São Carlos Theater in Lisbon, Portugal

    Science.gov (United States)

    Fontul, S.; Solla, M.; Cruz, H.; Machado, J. S.; Pajewski, L.

    2018-05-01

    This paper describes a study conducted by the National Laboratory for Civil Engineering of Portugal (LNEC), in cooperation with the Defense University Center at the Spanish Naval Academy and "La Sapienza," University of Rome, to assess the health and safety conditions of the Noble Hall floor in the São Carlos National Theater (Lisbon, Portugal). In a multidisciplinary approach, extensive fieldwork was carried out. The survey included the location and characterization of beams in the various areas of the floor by using two ground penetrating radar (GPR) systems equipped with two different ground- or air-coupled antennas, local inspection openings to visually assess the geometry, timber species and conservation state of structural members, and an assessment of the conservation state of the timber beam ends using drilling equipment. All the tests performed and the results obtained are presented. The potential of using non-destructive tests for the inspection of timber cultural heritage structures, particularly GPR, is discussed, and some practical recommendations are made.

  10. Ground penetrating radar and seismic refraction investigation of fracture patterns in the basalt of Lucky Peak near Boise, Idaho

    International Nuclear Information System (INIS)

    Dougherty, M.E.; Hudson, W.K.; Kay, S.E.; Vincent, R.J.

    1994-01-01

    In hard rock environments, fluid flow and basement integrity are often controlled by the degree and connectivity of fracturing on an outcrop scale, rather than strictly by laboratory values of the permeability and competence of the matrix rock. Therefore, in many cases it is important to have a subsurface image of fracture characteristics of rock units in addition to an image of gross rock type. Fortunately, within a single rock type, many physical properties on outcrop scale are greatly influenced by fracturing, and changes in these physical properties should be detectable through the innovative use of geophysical methods. Work presented here is an attempt to use surface geophysical methods to delineate areas within a basalt flow which display different fracture characteristics and which have different electrical and seismic properties. The Basalt of Luck Peak is an intracanyon basalt flow exposed in cliffs around Lucky Peak Reservoir and in a terrace downstream from Lucky Peak Dam near Boise, Idaho. Visible in the face of the terrace below Lucky Peak Dam are the colonnade and entablature structures characteristic of differential cooling rates within basalt flows. Exposure of structural units within the cliff face is used to ground truth results from ground penetrating radar (GPR) and seismic refraction data collected along a line running perpendicular and away from the top edge of the cliff. 19 refs., 6 figs

  11. Photoelectric radar servo control system based on ARM+FPGA

    Science.gov (United States)

    Wu, Kaixuan; Zhang, Yue; Li, Yeqiu; Dai, Qin; Yao, Jun

    2016-01-01

    In order to get smaller, faster, and more responsive requirements of the photoelectric radar servo control system. We propose a set of core ARM + FPGA architecture servo controller. Parallel processing capability of FPGA to be used for the encoder feedback data, PWM carrier modulation, A, B code decoding processing and so on; Utilizing the advantage of imaging design in ARM Embedded systems achieves high-speed implementation of the PID algorithm. After the actual experiment, the closed-loop speed of response of the system cycles up to 2000 times/s, in the case of excellent precision turntable shaft, using a PID algorithm to achieve the servo position control with the accuracy of + -1 encoder input code. Firstly, This article carry on in-depth study of the embedded servo control system hardware to determine the ARM and FPGA chip as the main chip with systems based on a pre-measured target required to achieve performance requirements, this article based on ARM chip used Samsung S3C2440 chip of ARM7 architecture , the FPGA chip is chosen xilinx's XC3S400 . ARM and FPGA communicate by using SPI bus, the advantage of using SPI bus is saving a lot of pins for easy system upgrades required thereafter. The system gets the speed datas through the photoelectric-encoder that transports the datas to the FPGA, Then the system transmits the datas through the FPGA to ARM, transforms speed datas into the corresponding position and velocity data in a timely manner, prepares the corresponding PWM wave to control motor rotation by making comparison between the position data and the velocity data setted in advance . According to the system requirements to draw the schematics of the photoelectric radar servo control system and PCB board to produce specially. Secondly, using PID algorithm to control the servo system, the datas of speed obtained from photoelectric-encoder is calculated position data and speed data via high-speed digital PID algorithm and coordinate models. Finally, a

  12. Measuring soil frost depth in forest ecosystems with ground penetrating radar

    Science.gov (United States)

    John R. Butnor; John L. Campbell; James B. Shanley; Stanley. Zarnoch

    2014-01-01

    Soil frost depth in forest ecosystems can be variable and depends largely on early winter air temperatures and the amount and timing of snowfall. A thorough evaluation of ecological responses to seasonally frozen ground is hampered by our inability to adequately characterize the frequency, depth, duration and intensity of soil frost events. We evaluated the use of...

  13. Robotic Ground-Penetrating-Radar (GPR) Surveys to Support the 2014 Greenland Inland Traverse

    Science.gov (United States)

    2016-06-01

    return via the same route to Thule in late May for over- winter equipment storage. The first 100 km of the route onto the main ice cap is ridden with...vehicle has a nominal ground pressure of 20 kPa through 0.51 m diameter all-terrain vehicle (ATV) tires . Yeti there- fore can drive safely over most

  14. Design of an Ultra-wideband Pseudo Random Coded MIMO Radar Based on Radio Frequency Switches

    Directory of Open Access Journals (Sweden)

    Su Hai

    2017-02-01

    Full Text Available A Multiple-Input Multiple-Output (MIMO ultra-wideband radar can detect the range and azimuth information of targets in real time. It is widely used for geological surveys, life rescue, through-wall tracking, and other military or civil fields. This paper presents the design of an ultra-wideband pseudo random coded MIMO radar that is based on Radio Frequency (RF switches and implements a MIMO radar system. RF switches are employed to reduce cost and complexity of the system. As the switch pressure value is limited, the peak power of the transmitting signal is 18 dBm. The ultra-wideband radar echo is obtained by hybrid sampling, and pulse compression is computed by Digital Signal Processors (DSPs embedded in an Field-Programmable Gate Array (FPGA to simplify the signal process. The experiment illustrates that the radar system can detect the range and azimuth information of targets in real time.

  15. COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar": first-year activities and results

    Science.gov (United States)

    Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Slob, Evert; Tosti, Fabio

    2014-05-01

    This work aims at presenting the first-year activities and results of COST (European COoperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar". This Action was launched in April 2013 and will last four years. The principal aim of COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Moreover, the Action is oriented to the following specific objectives and expected deliverables: (i) coordinating European scientists to highlight problems, merits and limits of current GPR systems; (ii) developing innovative protocols and guidelines, which will be published in a handbook and constitute a basis for European standards, for an effective GPR application in civil- engineering tasks; safety, economic and financial criteria will be integrated within the protocols; (iii) integrating competences for the improvement and merging of electromagnetic scattering techniques and of data- processing techniques; this will lead to a novel freeware tool for the localization of buried objects, shape-reconstruction and estimation of geophysical parameters useful for civil engineering needs; (iv) networking for the design, realization and optimization of innovative GPR equipment; (v) comparing GPR with different NDT techniques, such as ultrasonic, radiographic, liquid-penetrant, magnetic-particle, acoustic-emission and eddy-current testing; (vi) comparing GPR technology and methodology used in civil engineering with those used in other fields; (vii) promotion of a more widespread, advanced and efficient use of GPR in civil engineering; and (viii) organization of a high-level modular training program for GPR European users. Four Working Groups (WGs) carry out the research activities. The first WG

  16. Ground penetrating radar study of a thickness of biogenic sediments in the vicinity of the Czechowskie Lake

    Science.gov (United States)

    Lamparski, Piotr

    2014-05-01

    The paper present results of investigations, which have made on a biogenic plain in the north-east part of the vicinity of the Czechowskie Lake. The basin of Lake Czechowskie occupies a deep depression located in the immediate hinterland of the maximum range of the Pomeranian Phase ice sheet in the northern part of Poland (Błaszkiewicz 2005). Drillings carried out within the peat plain in the western part of the lake basin indicate that there are relatively diversified lake sediments of up to 12 m in thickness. The ground penetrating radar profiling method (GPR) was used to determine a thickness of biogenic sediments. To tests was used GSS'I SIR SYSTEM-2000™ radar device with two antennae - the high resolution 400 MHz central frequency - for shallow prospecting of the subsurface layers and the low resolution 35 MHz - for determining the shape of the mineral bedrock. Overall, 33 GPR profiles was made all in all more than 3000 meters along and crosswise the longer axis of the biogenic plain. The range of radar penetration was set to 200 ns for 400 MHz antenna and 600 ns for the 35 MHz one, what is the equivalent respectively 4 m and 12,5 m in depth of biogenic sediments thickness. Horizontal scaling was made by GSSI survey wheel device. The thickness of biogenic sediments recognized by GPR reaches 10 meters only using 35 MHz antenna. In the case of the 400 MHz antenna, relatively high conductivity water-saturated peat and gyttia did not allow for the achievement of greater thickness than 3-4 meters testing. In a large part of the profiles was able to see the shape of the mineral bedrock in the form of a former lake basin. Also observed elevations and thresholds in the bedrock. Depth of the mineral deposits forming former lake bottom was confirmed by drillings. This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analysis -ICLEA- of the Helmholtz Association. References: Błaszkiewicz M, 2005. Późnoglacjalna i

  17. A Dynamic and Adaptive Selection Radar Tracking Method Based on Information Entropy

    Directory of Open Access Journals (Sweden)

    Ge Jianjun

    2017-12-01

    Full Text Available Nowadays, the battlefield environment has become much more complex and variable. This paper presents a quantitative method and lower bound for the amount of target information acquired from multiple radar observations to adaptively and dynamically organize the detection of battlefield resources based on the principle of information entropy. Furthermore, for minimizing the given information entropy’s lower bound for target measurement at every moment, a method to dynamically and adaptively select radars with a high amount of information for target tracking is proposed. The simulation results indicate that the proposed method has higher tracking accuracy than that of tracking without adaptive radar selection based on entropy.

  18. Illumination compensation in ground based hyperspectral imaging

    Science.gov (United States)

    Wendel, Alexander; Underwood, James

    2017-07-01

    Hyperspectral imaging has emerged as an important tool for analysing vegetation data in agricultural applications. Recently, low altitude and ground based hyperspectral imaging solutions have come to the fore, providing very high resolution data for mapping and studying large areas of crops in detail. However, these platforms introduce a unique set of challenges that need to be overcome to ensure consistent, accurate and timely acquisition of data. One particular problem is dealing with changes in environmental illumination while operating with natural light under cloud cover, which can have considerable effects on spectral shape. In the past this has been commonly achieved by imaging known reference targets at the time of data acquisition, direct measurement of irradiance, or atmospheric modelling. While capturing a reference panel continuously or very frequently allows accurate compensation for illumination changes, this is often not practical with ground based platforms, and impossible in aerial applications. This paper examines the use of an autonomous unmanned ground vehicle (UGV) to gather high resolution hyperspectral imaging data of crops under natural illumination. A process of illumination compensation is performed to extract the inherent reflectance properties of the crops, despite variable illumination. This work adapts a previously developed subspace model approach to reflectance and illumination recovery. Though tested on a ground vehicle in this paper, it is applicable to low altitude unmanned aerial hyperspectral imagery also. The method uses occasional observations of reference panel training data from within the same or other datasets, which enables a practical field protocol that minimises in-field manual labour. This paper tests the new approach, comparing it against traditional methods. Several illumination compensation protocols for high volume ground based data collection are presented based on the results. The findings in this paper are

  19. Exchanging knowledge and working together in COST Action TU1208: Short-Term Scientific Missions on Ground Penetrating Radar

    Science.gov (United States)

    Santos Assuncao, Sonia; De Smedt, Philippe; Giannakis, Iraklis; Matera, Loredana; Pinel, Nicolas; Dimitriadis, Klisthenis; Giannopoulos, Antonios; Sala, Jacopo; Lambot, Sébastien; Trinks, Immo; Marciniak, Marian; Pajewski, Lara

    2015-04-01

    This work aims at presenting the scientific results stemming from six Short-Term Scientific Missions (STSMs) funded by the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar' (Action Chair: Lara Pajewski, STSM Manager: Marian Marciniak). STSMs are important means to develop linkages and scientific collaborations between participating institutions involved in a COST Action. Scientists have the possibility to go to an institution abroad, in order to undertake joint research and share techniques/equipment/infrastructures that may not be available in their own institution. STSMs are particularly intended for Early Stage Researchers (ESRs), i.e., young scientists who obtained their PhD since no more than 8 years when they started to be involved in the Action. Duration of a standard STSM can be from 5 to 90 days and the research activities carried out during this short stay shall specifically contribute to the achievement of the scientific objectives of the supporting COST Action. The first STSM was carried out by Lara Pajewski, visiting Antonis Giannopoulos at The University of Edinburgh (United Kingdom). The research activities focused on the electromagnetic modelling of Ground Penetrating Radar (GPR) responses to complex targets. A set of test scenarios was defined, to be used by research groups participating to Working Group 3 of COST Action TU1208, to test and compare different electromagnetic forward- and inverse-scattering methods; these scenarios were modelled by using the well-known finite-difference time-domain simulator GprMax. New Matlab procedures for the processing and visualization of GprMax output data were developed. During the second STSM, Iraklis Giannakis visited Lara Pajewski at Roma Tre University (Italy). The study was concerned with the numerical modelling of horn antennas for GPR. An air-coupled horn antenna was implemented in GprMax and tested in a realistically

  20. Ground-based observations coordinated with Viking satellite measurements

    International Nuclear Information System (INIS)

    Opgenoorth, H.J.; Kirkwood, S.

    1989-01-01

    The instrumentation and the orbit of the Viking satellite made this first Swedish satellite mission ideally suited for coordinated observations with the dense network of ground-based stations in northern Scandinavia. Several arrays of complementing instruments such as magnetometers, all-sky cameras, riometers and doppler radars monitored on a routine basis the ionosphere under the magnetospheric region passed by Viking. For a large number of orbits the Viking passages close to Scandinavia were covered by the operation of specially designed programmes at the European incoherent-scatter facility (EISCAT). First results of coordinated observations on the ground and aboard Viking have shed new light on the most spectacular feature of substorm expansion, the westward-travelling surge. The end of a substorm and the associated decay of a westward-travelling surge have been analysed. EISCAT measurements of high spatial and temporal resolution indicate that the conductivities and electric fields associated with westward-travelling surges are not represented correctly by the existing models. (author)

  1. Copula-based assimilation of radar and gauge information to derive bias-corrected precipitation fields

    Directory of Open Access Journals (Sweden)

    S. Vogl

    2012-07-01

    Full Text Available This study addresses the problem of combining radar information and gauge measurements. Gauge measurements are the best available source of absolute rainfall intensity albeit their spatial availability is limited. Precipitation information obtained by radar mimics well the spatial patterns but is biased for their absolute values.

    In this study copula models are used to describe the dependence structure between gauge observations and rainfall derived from radar reflectivity at the corresponding grid cells. After appropriate time series transformation to generate "iid" variates, only the positive pairs (radar >0, gauge >0 of the residuals are considered. As not each grid cell can be assigned to one gauge, the integration of point information, i.e. gauge rainfall intensities, is achieved by considering the structure and the strength of dependence between the radar pixels and all the gauges within the radar image. Two different approaches, namely Maximum Theta and Multiple Theta, are presented. They finally allow for generating precipitation fields that mimic the spatial patterns of the radar fields and correct them for biases in their absolute rainfall intensities. The performance of the approach, which can be seen as a bias-correction for radar fields, is demonstrated for the Bavarian Alps. The bias-corrected rainfall fields are compared to a field of interpolated gauge values (ordinary kriging and are validated with available gauge measurements. The simulated precipitation fields are compared to an operationally corrected radar precipitation field (RADOLAN. The copula-based approach performs similarly well as indicated by different validation measures and successfully corrects for errors in the radar precipitation.

  2. Evaluation of 3D Ground Penetrating Radar Efficiency for Abandoned Tailings Pond Internal Structure Analysis and Risk Assessment

    Science.gov (United States)

    Cortada, Unai; Martínez, Julián; Hidalgo, Mª Carmen; Rey, Javier

    2017-04-01

    Evaluation of 3D Ground Penetrating Radar Efficiency for Abandoned Tailings Pond Internal Structure Analysis and Risk Assessment Abandoned tailings ponds constitute a severe environmental problem in old Pb mining districts due to their high contents in metallic and semi-metallic elements. In most of the cases, there is a lack of information about the construction procedures and the previous environmental situation, which hinders the environmental risk evaluation. In these cases, Ground Penetrating Radar (GPR) could be an interesting technique to analyze the internal structure of the tailings ponds and detect vulnerable zones for leaching processes. Consequently, the GPR could help in the abandoned tailings ponds environmental risk assessment. In this study, a GPR 3D campaign was carried out with a 250 MHz frequency antenna in order to evaluate the efficiency of this technique in both the analysis of internal structures and the environmental risk assessment. Subsequently, 2D and 3D models were undertaken to represent graphically the obtained results. The studied tailings pond is located in the Guadiel river bank, a water course draining the mining district of Linares, Spain. The dam is 150 m length and 80 m width. The GPR 3D was done in a selected area near the central part of the pond. The analyzed grid was 25x50 m and the spacing of the slides was 1 m. The study revealed that the contact between the tailings and the substratum is located at 2.5 m. No intermediate layer was found, which means that the tailings pond was heightened on the fluvial terrace without any insulation system. Inside the first meter of the pond, a cross stratification was identified. The orientation of those laminations changed with the depth, which means that the stockpiling was performed from the different sides of the tailings pond. Furthermore, the direction of these stratifications is slightly concentric to the middle of the dam which could be associated with a central drainage system

  3. Calibration of Ground -based Lidar instrument

    DEFF Research Database (Denmark)

    Villanueva, Héctor; Yordanova, Ginka

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...

  4. Performance of UWB Array-Based Radar Sensor in a Multi-Sensor Vehicle-Based Suit for Landmine Detection

    NARCIS (Netherlands)

    Yarovoy, A.; Savelyev, T.; Zhuge, X.; Aubry, P.; Ligthart, L.; Schavemaker, J.G.M.; Tettelaar, P.; Breejen, E. de

    2008-01-01

    In this paper, integration of an UWB array-based timedomain radar sensor in a vehicle-mounted multi-sensor system for landmine detection is described. Dedicated real-time signal processing algorithms are developed to compute the radar sensor confidence map which is used for sensor fusion.

  5. Interpretation of the distortion of ground-penetrating radar propagated and reflected waves - development of a multi-frequency tomography; Interpretation de la distorsion des signaux georadar propages et reflechis. Developpement d'une tomographie par bandes de frequence

    Energy Technology Data Exchange (ETDEWEB)

    Hollender, F

    1999-07-01

    Within the framework of research for waste disposal in deep geological formations, the French agency for nuclear waste management (ANDRA) has to dispose of non-destructive investigation methods to characterize the medium. Ground penetrating radar (GPR) could be used for this purpose in the case of granitic sites. The work presented here deals with this geophysical method. The classical interpretation of GPR data consists in the localization of geological discontinuities by signal amplitude or arrival time analysis. The main objective of our studies is the interpretation of the radar wave distortion (due to propagation and reflection phenomena), not only to localize discontinuities but also to contribute to their identification. Three preliminary studies have been carried out in order to understand on the one hand, the complexity of the electromagnetic phenomena in the geological medium at radar frequency, and on the other hand, the radar equipment constraints. First, the dispersion and the attenuation characterized by a Q variable factor of the GPR waves are shown with the support of dielectric laboratory measurements. A model, which only requires three parameters, is proposed in order to describe this behavior. Second, the radiation patterns of borehole radar antenna are studied. We show that the amplitude and frequency content of the emitted signal are variable versus the emission angle. An analytical method is proposed to study these phenomena. Finally, instrumental drifts of GPR equipment are studied. Emission time, sampling frequency and amplitude fluctuations are described. These elements are taken into account for the processing of propagated signals by tomographic inversion. Medium anisotropy and borehole trajectory errors are inserted in algorithms in order to cancel artifacts which compromised the previous interpretation. A pre-processing method, based on wave separation algorithm, is applied on data in order to increase tomogram resolution. A new

  6. Combining 3D seismic tomography and ground-penetrating radar to reveal the structure of a megalithic burial tomb

    Science.gov (United States)

    Mendes, Manuela; Caldeira, Bento; Borges, José

    2017-04-01

    This work describes a case study concerning a prehistoric buried tomb (around 3000 years B.C.) located near Évora (Portugal). This monument is a tomb completely buried with only five visible irregular small stones distributed in a circle of 3 meter in diameter. A multi-approach combining 3D seismic tomography and ground-penetrating radar (GPR) have been applied to identify hidden elements and arrangement of the stones, required prior to any excavation work. The methodology for the 3D seismic data acquisition involves a total of 24 shots recorded by four lines, with twelve fixed receivers each one. For the GPR survey was used a 400 MHz antenna which moves along parallel lines with 50 cm separation, over a 30x30 m2 area that contains the buried tomb; the GPR unit was configured to a horizontal rate of 50 scans per meter (1024 samples/scan) and a time window of 60 ns. This multi-approach procedure allowed defining: (i) the housing of the tomb in the basement structure; (ii) the presence of a hidden corridor; (iii) the description of the internal structure of the walls of the tomb; (iv) the state of preservation of the monument. Acknowledgements: This work is co-financed by the European Union through the European Regional Development Fund under COMPETE 2020 (Operational Program for Competitiveness and Internationalization) through the ICT project (UID / GEO / 04683/2013) under the reference POCI-01-0145 -FEDER-007690.

  7. Integration of ground-penetrating radar, ultrasonic tests and infrared thermography for the analysis of a precious medieval rose window

    Science.gov (United States)

    Nuzzo, L.; Calia, A.; Liberatore, D.; Masini, N.; Rizzo, E.

    2010-04-01

    The integration of high-resolution, non-invasive geophysical techniques (such as ground-penetrating radar or GPR) with emerging sensing techniques (acoustics, thermography) can complement limited destructive tests to provide a suitable methodology for a multi-scale assessment of the state of preservation, material and construction components of monuments. This paper presents the results of the application of GPR, infrared thermography (IRT) and ultrasonic tests to the 13th century rose window of Troia Cathedral (Apulia, Italy), affected by widespread decay and instability problems caused by the 1731 earthquake and reactivated by recent seismic activity. This integrated approach provided a wide amount of complementary information at different scales, ranging from the sub-centimetre size of the metallic joints between the various architectural elements, narrow fractures and thin mortar fillings, up to the sub-metre scale of the internal masonry structure of the circular ashlar curb linking the rose window to the façade, which was essential to understand the original building technique and to design an effective restoration strategy.

  8. Ground-penetrating radar investigation of St. Leonard's Crypt under the Wawel Cathedral (Cracow, Poland) - COST Action TU1208

    Science.gov (United States)

    Benedetto, Andrea; Pajewski, Lara; Dimitriadis, Klisthenis; Avlonitou, Pepi; Konstantakis, Yannis; Musiela, Małgorzata; Mitka, Bartosz; Lambot, Sébastien; Żakowska, Lidia

    2016-04-01

    The Wawel ensemble, including the Royal Castle, the Wawel Cathedral and other monuments, is perched on top of the Wawel hill immediately south of the Cracow Old Town, and is by far the most important collection of buildings in Poland. St. Leonard's Crypt is located under the Wawel Cathedral of St Stanislaus BM and St Wenceslaus M. It was built in the years 1090-1117 and was the western crypt of the pre-existing Romanesque Wawel Cathedral, so-called Hermanowska. Pope John Paul II said his first Mass on the altar of St. Leonard's Crypt on November 2, 1946, one day after his priestly ordination. The interior of the crypt is divided by eight columns into three naves with vaulted ceiling and ended with one apse. The tomb of Bishop Maurus, who died in 1118, is in the middle of the crypt under the floor; an inscription "+ MAVRVS EPC MCXVIII +" indicates the burial place and was made in 1938 after the completion of archaeological works which resulted in the discovery of this tomb. Moreover, the crypt hosts the tombs of six Polish kings and heroes: Michał Korybut Wiśniowiecki (King of the Polish-Lithuanian Commonwealth), Jan III Sobieski (King of the Polish-Lithuanian Commonwealth and Commander at the Battle of Vienna), Maria Kazimiera (Queen of the Polish-Lithuanian Commonwealth and consort to Jan III Sobieski), Józef Poniatowski (Prince of Poland and Marshal of France), Tadeusz Kościuszko (Polish general, revolutionary and a Brigadier General in the American Revolutionary War) and Władysław Sikorski (Prime Minister of the Polish Government in Exile and Commander-in-Chief of the Polish Armed Forces). The adjacent six crypts and corridors host the tombs of the other Polish kings, from Sigismund the Old to Augustus II the Strong, their families and several Polish heroes. In May 2015, the COST (European COoperation in Science and Technology) Action TU1208 "Civil engineering applications of Ground Penetrating Radar" organised and offered a Training School (TS) on the

  9. Experimental Evaluation of Several Key Factors Affecting Root Biomass Estimation by 1500 MHz Ground-Penetrating Radar

    Directory of Open Access Journals (Sweden)

    John C. Bain

    2017-12-01

    Full Text Available Accurate quantification of coarse roots without disturbance represents a gap in our understanding of belowground ecology. Ground penetrating radar (GPR has shown significant promise for coarse root detection and measurement, however root orientation relative to scanning transect direction, the difficulty identifying dead root mass, and the effects of root shadowing are all key factors affecting biomass estimation that require additional research. Specifically, many aspects of GPR applicability for coarse root measurement have not been tested with a full range of antenna frequencies. We tested the effects of multiple scanning directions, root crossover, and root versus soil moisture content in a sand-hill mixed oak community using a 1500 MHz antenna, which provides higher resolution than the oft used 900 MHz antenna. Combining four scanning directions produced a significant relationship between GPR signal reflectance and coarse root biomass (R2 = 0.75 (p < 0.01 and reduced variability encountered when fewer scanning directions were used. Additionally, significantly fewer roots were correctly identified when their moisture content was allowed to equalize with the surrounding soil (p < 0.01, providing evidence to support assertions that GPR cannot reliably identify dead root mass. The 1500 MHz antenna was able to identify roots in close proximity of each other as well as roots shadowed beneath shallower roots, providing higher precision than a 900 MHz antenna. As expected, using a 1500 MHz antenna eliminates some of the deficiency in precision observed in studies that utilized lower frequency antennas.

  10. Integration of electrical resistivity imaging and ground penetrating radar to investigate solution features in the Biscayne Aquifer

    Science.gov (United States)

    Yeboah-Forson, Albert; Comas, Xavier; Whitman, Dean

    2014-07-01

    The limestone composing the Biscayne Aquifer in southeast Florida is characterized by cavities and solution features that are difficult to detect and quantify accurately because of their heterogeneous spatial distribution. Such heterogeneities have been shown by previous studies to exert a strong influence in the direction of groundwater flow. In this study we use an integrated array of geophysical methods to detect the lateral extent and distribution of solution features as indicative of anisotropy in the Biscayne Aquifer. Geophysical methods included azimuthal resistivity measurements, electrical resistivity imaging (ERI) and ground penetrating radar (GPR) and were constrained with direct borehole information from nearby wells. The geophysical measurements suggest the presence of a zone of low electrical resistivity (from ERI) and low electromagnetic wave velocity (from GPR) below the water table at depths of 4-9 m that corresponds to the depth of solution conduits seen in digital borehole images. Azimuthal electrical measurements at the site reported coefficients of electrical anisotropy as high as 1.36 suggesting the presence of an area of high porosity (most likely comprising different types of porosity) oriented in the E-W direction. This study shows how integrated geophysical methods can help detect the presence of areas of enhanced porosity which may influence the direction of groundwater flow in a complex anisotropic and heterogeneous karst system like the Biscayne Aquifer.

  11. Architectural element analysis within the Kayenta Formation (Lower Jurassic) using ground-probing radar and sedimentological profiling, southwestern Colorado

    Science.gov (United States)

    Stephens, Mark

    1994-05-01

    A well exposed outcrop in the Kayenta Formation (Lower Jurassic) in southwestern Colorado was examined in order to delineate the stratigraphy in the subsurface and test the usefulness of ground-probing radar (GPR) in three-dimensional architectural studies. Two fluvial styles are present within the Kayenta Formation. Sandbodies within the lower third of the outcrop are characterized by parallel laminations that can be followed in the cliff-face for well over 300 m. These sandbodies are sheet-like in appearance, and represent high-energy flood deposits that most likely resulted from episodic floods. The remainder of the outcrop is characterized by concave-up channel deposits with bank-attached and mid-channel macroforms. Their presence suggests a multiple channel river system. The GPR data collected on the cliff-top, together with sedimentological data, provided a partial three-dimensional picture of the paleo-river system within the Kayenta Formation. The 3-D picture consists of stacked channel-bar lenses approximately 50 m in diameter. The GPR technique offers a very effective means of delineating the subsurface stratigraphy. Its high resolution capabilities, easy mobility, and rapid rate of data collection make it a useful tool. Its shallow penetration depth and limitation to low-conductivity environments are its only drawbacks.

  12. Signal Processing of Ground Penetrating Radar Using Spectral Estimation Techniques to Estimate the Position of Buried Targets

    Directory of Open Access Journals (Sweden)

    Shanker Man Shrestha

    2003-11-01

    Full Text Available Super-resolution is very important for the signal processing of GPR (ground penetration radar to resolve closely buried targets. However, it is not easy to get high resolution as GPR signals are very weak and enveloped by the noise. The MUSIC (multiple signal classification algorithm, which is well known for its super-resolution capacity, has been implemented for signal and image processing of GPR. In addition, conventional spectral estimation technique, FFT (fast Fourier transform, has also been implemented for high-precision receiving signal level. In this paper, we propose CPM (combined processing method, which combines time domain response of MUSIC algorithm and conventional IFFT (inverse fast Fourier transform to obtain a super-resolution and high-precision signal level. In order to support the proposal, detailed simulation was performed analyzing SNR (signal-to-noise ratio. Moreover, a field experiment at a research field and a laboratory experiment at the University of Electro-Communications, Tokyo, were also performed for thorough investigation and supported the proposed method. All the simulation and experimental results are presented.

  13. Ground penetrating radar and differential global positioning system data collected in April 2016 from Fire Island, New York

    Science.gov (United States)

    Forde, Arnell S.; Bernier, Julie C.; Miselis, Jennifer L.

    2018-02-22

    Researchers from the U.S. Geological Survey (USGS) conducted a long-term coastal morphologic-change study at Fire Island, New York, prior to and after Hurricane Sandy impacted the area in October 2012. The Fire Island Coastal Change project objectives include understanding the morphologic evolution of the barrier island system on a variety of time scales (months to centuries) and resolving storm-related impacts, post-storm beach response, and recovery. In April 2016, scientists from the USGS St. Petersburg Coastal and Marine Science Center conducted geophysical and sediment sampling surveys on Fire Island to characterize and quantify spatial variability in the subaerial geology with the goal of subsequently integrating onshore geology with other surf zone and nearshore datasets.  This report, along with the associated USGS data release, serves as an archive of ground penetrating radar (GPR) and post-processed differential global positioning system (DGPS) data collected from beach and back-barrier environments on Fire Island, April 6–13, 2016 (USGS Field Activity Number 2016-322-FA). Data products, including unprocessed GPR trace data, processed DGPS data, elevation-corrected subsurface profile images, geographic information system files, and accompanying Federal Geographic Data Committee metadata are available for download.

  14. Estimating Carbon Stocks Along Depressional Wetlands Using Ground Penetrating Radar (GPR) in the Disney Wilderness Preserve (Orlando, Florida)

    Science.gov (United States)

    McClellan, M. D.; Comas, X.; Wright, W. J.; Mount, G. J.

    2014-12-01

    Peat soils store a large fraction of the global carbon (C) in soil. It is estimated that 95% of carbon in peatlands is stored in the peat soil, while less than 5% occurs in the vegetation. The majority of studies related to C stocks in peatlands have taken place in northern latitudes leaving the tropical and subtropical latitudes clearly understudied. In this study we use a combination of indirect non-invasive geophysical methods (mainly ground penetrating radar, GPR) as well as direct measurements (direct coring) to calculate total C stocks within subtropical depressional wetlands in the Disney Wilderness Preserve (DWP, Orlando, FL). A set of three-dimensional (3D) GPR surveys were used to detect variability of the peat layer thickness and the underlying peat-sand mix layer across several depressional wetlands. Direct samples collected at selected locations were used to confirm depth of each interface and to estimate C content in the laboratory. Layer thickness estimated from GPR and direct C content were used to estimate total peat volume and C content for the entire depressional wetland. Through the use of aerial photos a relationship between surface area along the depressional wetlands and total peat thickness (and thus C content) was established for the depressions surveyed and applied throughout the entire preserve. This work shows the importance of depressional wetlands as critical contributors of the C budget at the DWP.

  15. Investigating Hydrogeologic Controls on Sandhill Wetlands in Covered Karst with 2D Resistivity and Ground Penetrating Radar

    Science.gov (United States)

    Downs, C. M.; Nowicki, R. S.; Rains, M. C.; Kruse, S.

    2015-12-01

    In west-central Florida, wetland and lake distribution is strongly controlled by karst landforms. Sandhill wetlands and lakes are sand-filled upland basins whose water levels are groundwater driven. Lake dimensions only reach wetland edges during extreme precipitation events. Current wetland classification schemes are inappropriate for identifying sandhill wetlands due to their unique hydrologic regime and ecologic expression. As a result, it is difficult to determine whether or not a wetland is impacted by groundwater pumping, development, and climate change. A better understanding of subsurface structures and how they control the hydrologic regime is necessary for development of an identification and monitoring protocol. Long-term studies record vegetation diversity and distribution, shallow ground water levels and surface water levels. The overall goals are to determine the hydrologic controls (groundwater, seepage, surface water inputs). Most recently a series of geophysical surveys was conducted at select sites in Hernando and Pasco County, Florida. Electrical resistivity and ground penetrating radar were employed to image sand-filled basins and the top of the limestone bedrock and stratigraphy of wetland slopes, respectively. The deepest extent of these sand-filled basins is generally reflected in topography as shallow depressions. Resistivity along inundated wetlands suggests the pools are surface expressions of the surficial aquifer. However, possible breaches in confining clay layers beneath topographic highs between depressions are seen in resistivity profiles as conductive anomalies and in GPR as interruptions in otherwise continuous horizons. These data occur at sites where unconfined and confined water levels are in agreement, suggesting communication between shallow and deep groundwater. Wetland plants are observed outside the historic wetland boundary at many sites, GPR profiles show near-surface layers dipping towards the wetlands at a shallower

  16. Monitoring Ground Subsidence in Hong Kong via Spaceborne Radar: Experiments and Validation

    Directory of Open Access Journals (Sweden)

    Yuxiao Qin

    2015-08-01

    Full Text Available The persistent scatterers interferometry (PSI technique is gradually becoming known for its capability of providing up to millimeter accuracy of measurement on ground displacement. Nevertheless, there is still quite a good amount of doubt regarding its correctness or accuracy. In this paper, we carried out an experiment corroborating the capability of the PSI technique with the help of a traditional survey method in the urban area of Hong Kong, China. Seventy three TerraSAR-X (TSX and TanDEM-X (TDX images spanning over four years are used for the data process. There are three aims of this study. The first is to generate a displacement map of urban Hong Kong and to check for spots with possible ground movements. This information will be provided to the local surveyors so that they can check these specific locations. The second is to validate if the accuracy of the PSI technique can indeed reach the millimeter level in this real application scenario. For validating the accuracy of PSI, four corner reflectors (CR were installed at a construction site on reclaimed land in Hong Kong. They were manually moved up or down by a few to tens of millimeters, and the value derived from the PSI analysis was compared to the true value. The experiment, carried out in unideal conditions, nevertheless proved undoubtedly that millimeter accuracy can be achieved by the PSI technique. The last is to evaluate the advantages and limitations of the PSI technique. Overall, the PSI technique can be extremely useful if used in collaboration with other techniques, so that the advantages can be highlighted and the drawbacks avoided.

  17. Forecasting slope failures from space-based synthetic aperture radar (SAR) measurements

    Science.gov (United States)

    Wasowski, J.; Bovenga, F.; Nutricato, R.; Nitti, D. O.; Chiaradia, M. T.; Tijani, K.; Morea, A.

    2017-12-01

    New space-borne radar sensors enable multi-scale monitoring of potentially unstable slopes thanks to wide-area coverage (tens of thousands km2), regular long-term image acquisition schedule with increasing re-visit frequency (weekly to daily), and high measurement precision (mm). In particular, the recent radar satellite missions e.g., COSMO-SkyMed (CSK), Sentinel-1 (S-1) and improved multi-temporal interferometry (MTI) processing techniques allow timely delivery of information on slow ground surface displacements. Here we use two case study examples to show that it is possible to capture pre-failure slope strains through long-term MTI-based monitoring. The first case is a retrospective investigation of a huge 500ML m3 landslide, which occurred in Sept. 2016 in a large, active open-cast coal mine in central Europe. We processed over 100 S-1 images acquired since Fall 2014. The MTI results showed that the slope that failed had been unstable at least since 2014. Importantly, we detected consistent displacement trends and trend changes, which can be used for slope failure forecasting. Specifically, we documented significant acceleration in slope surface displacement in the two months preceding the catastrophic failure. The second case of retrospectively captured pre-failure slope strains regards our earlier study of a small 50 m long landslide, which occurred on Jan. 2014 and caused the derailment of a train on the railway line connecting NW Italy to France. We processed 56 CSK images acquired from Fall 2008 to Spring 2014. The MTI results revealed pre-failure displacements of the engineering structures on the slope subsequently affected by the 2014 slide. The analysis of the MTI time series further showed that the displacements had been occurring since 2009. This information could have been used to forewarn the railway authority about the slope instability hazard. The above examples indicate that more frequent and consistent image acquisitions by the new radar

  18. Classification of freshwater ice conditions on the Alaskan Arctic Coastal Plain using ground penetrating radar and TerraSAR-X satellite data

    Science.gov (United States)

    Jones, Benjamin M.; Gusmeroli, Alessio; Arp, Christopher D.; Strozzi, Tazio; Grosse, Guido; Gaglioti, Benjamin V.; Whitman, Matthew S.

    2013-01-01

    Arctic freshwater ecosystems have responded rapidly to climatic changes over the last half century. Lakes and rivers are experiencing a thinning of the seasonal ice cover, which may increase potential over-wintering freshwater habitat, winter water supply for industrial withdrawal, and permafrost degradation. Here, we combined the use of ground penetrating radar (GPR) and high-resolution (HR) spotlight TerraSAR-X (TSX) satellite data (1.25 m resolution) to identify and characterize floating ice and grounded ice conditions in lakes, ponds, beaded stream pools, and an alluvial river channel. Classified ice conditions from the GPR and the TSX data showed excellent agreement: 90.6% for a predominantly floating ice lake, 99.7% for a grounded ice lake, 79.0% for a beaded stream course, and 92.1% for the alluvial river channel. A GIS-based analysis of 890 surface water features larger than 0.01 ha showed that 42% of the total surface water area potentially provided over-wintering habitat during the 2012/2013 winter. Lakes accounted for 89% of this area, whereas the alluvial river channel accounted for 10% and ponds and beaded stream pools each accounted for landscape features such as beaded stream pools may be important because of their distribution and role in connecting other water bodies on the landscape. These findings advance techniques for detecting and knowledge associated with potential winter habitat distribution for fish and invertebrates at the local scale in a region of the Arctic with increasing stressors related to climate and land use change.

  19. A GIS-based disaggregate spatial watershed analysis using RADAR data

    International Nuclear Information System (INIS)

    Al-Hamdan, M.

    2002-01-01

    Hydrology is the study of water in all its forms, origins, and destinations on the earth.This paper develops a novel modeling technique using a geographic information system (GIS) to facilitate watershed hydrological routing using RADAR data. The RADAR rainfall data, segmented to 4 km by 4 km blocks, divides the watershed into several sub basins which are modeled independently. A case study for the GIS-based disaggregate spatial watershed analysis using RADAR data is provided for South Fork Cowikee Creek near Batesville, Alabama. All the data necessary to complete the analysis is maintained in the ArcView GIS software. This paper concludes that the GIS-Based disaggregate spatial watershed analysis using RADAR data is a viable method to calculate hydrological routing for large watersheds. (author)

  20. Research on Radar Cross Section Measurement Based on Near-field Imaging of Cylindrical Scanning

    Directory of Open Access Journals (Sweden)

    Xing Shu-guang

    2015-04-01

    Full Text Available A new method of Radar Cross Section (RCS measurement based on near-field imaging of cylindrical scanning surface is proposed. The method is based on the core assumption that the target consists of ideal isotropic scattered centers. Three-dimensional radar scattered images are obtained by using the proposed method, and then to obtain the RCS of the target, the scattered far field is calculated by summing the fields generated by the equivalent scattered centers. Not only three dimensional radar reflectivity images but also the RCS of targets in certain three dimensional angle areas can be obtained. Compared with circular scanning that can only obtain twodimensional radar reflectivity images and RCS results in two-dimensional angle areas, cylindrical scanning can provide more information about the scattering properties of the targets. The method has strong practicability and its validity is verified by simulations.

  1. Multistatic Wireless Fidelity Network Based Radar – Results of the Chrcynno Experiment

    Directory of Open Access Journals (Sweden)

    S. Rzewuski

    2014-04-01

    Full Text Available This paper presents the theory and experimental result of passive radar using WIFI transmitters as illuminators of opportunity. As a result of experiments conducted on 17th August 2013 at airfield Chrcynno a Cessna C208 airplane was detected and tracked using multistatic passive radar system based on low power signal from WIFI network nodes, which were acting as non cooperative illuminators of opportunity. In the experiment 3 wireless access points were communicating with each other and illuminating the radar scene (airfield. The direct reference and reflected (surveillance signals have been acquired and processed using specially developed algorithm presented in the paper. After signal processing using Passive Coherent Location methods target has been detected. This paper describes in details the algorithms and the results of the experiment for the multistatic passive radar based on the WIFI signal.

  2. Long term landslide monitoring with Ground Based SAR

    Science.gov (United States)

    Monserrat, Oriol; Crosetto, Michele; Luzi, Guido; Gili, Josep; Moya, Jose; Corominas, Jordi

    2014-05-01

    In the last decade, Ground-Based (GBSAR) has proven to be a reliable microwave Remote Sensing technique in several application fields, especially for unstable slopes monitoring. GBSAR can provide displacement measurements over few squared kilometres areas and with a very high spatial and temporal resolution. This work is focused on the use of GBSAR technique for long term landslide monitoring based on a particular data acquisition configuration, which is called discontinuous GBSAR (D-GBSAR). In the most commonly used GBSAR configuration, the radar is left installed in situ, acquiring data periodically, e.g. every few minutes. Deformations are estimated by processing sets of GBSAR images acquired during several weeks or months, without moving the system. By contrast, in the D-GBSAR the radar is installed and dismounted at each measurement campaign, revisiting a given site periodically. This configuration is useful to monitor slow deformation phenomena. In this work, two alternative ways for exploiting the D-GBSAR technique will be presented: the DInSAR technique and the Amplitude based Technique. The former is based on the exploitation of the phase component of the acquired SAR images and it allows providing millimetric precision on the deformation estimates. However, this technique presents several limitations like the reduction of measurable points with an increase in the period of observation, the ambiguous nature of the phase measurements, and the influence of the atmospheric phase component that can make it non applicable in some cases, specially when working in natural environments. The second approach, that is based on the use of the amplitude component of GB-SAR images combined with a image matching technique, will allow the estimation of the displacements over specific targets avoiding two of the limitations commented above: the phase unwrapping and atmosphere contribution but reducing the deformation measurement precision. Two successful examples of D

  3. Space and Ground-Based Infrastructures

    Science.gov (United States)

    Weems, Jon; Zell, Martin

    This chapter deals first with the main characteristics of the space environment, outside and inside a spacecraft. Then the space and space-related (ground-based) infrastructures are described. The most important infrastructure is the International Space Station, which holds many European facilities (for instance the European Columbus Laboratory). Some of them, such as the Columbus External Payload Facility, are located outside the ISS to benefit from external space conditions. There is only one other example of orbital platforms, the Russian Foton/Bion Recoverable Orbital Capsule. In contrast, non-orbital weightless research platforms, although limited in experimental time, are more numerous: sounding rockets, parabolic flight aircraft, drop towers and high-altitude balloons. In addition to these facilities, there are a number of ground-based facilities and space simulators, for both life sciences (for instance: bed rest, clinostats) and physical sciences (for instance: magnetic compensation of gravity). Hypergravity can also be provided by human and non-human centrifuges.

  4. Doppler Radar Vital Signs Detection Method Based on Higher Order Cyclostationary.

    Science.gov (United States)

    Yu, Zhibin; Zhao, Duo; Zhang, Zhiqiang

    2017-12-26

    Due to the non-contact nature, using Doppler radar sensors to detect vital signs such as heart and respiration rates of a human subject is getting more and more attention. However, the related detection-method research meets lots of challenges due to electromagnetic interferences, clutter and random motion interferences. In this paper, a novel third-order cyclic cummulant (TOCC) detection method, which is insensitive to Gaussian interference and non-cyclic signals, is proposed to investigate the heart and respiration rate based on continuous wave Doppler radars. The k -th order cyclostationary properties of the radar signal with hidden periodicities and random motions are analyzed. The third-order cyclostationary detection theory of the heart and respiration rate is studied. Experimental results show that the third-order cyclostationary approach has better estimation accuracy for detecting the vital signs from the received radar signal under low SNR, strong clutter noise and random motion interferences.

  5. Closed form fourier-based transmit beamforming for MIMO radar

    KAUST Repository

    Lipor, John J.

    2014-05-01

    In multiple-input multiple-output (MIMO) radar setting, it is often desirable to design correlated waveforms such that power is transmitted only to a given set of locations, a process known as beampattern design. To design desired beam-pattern, current research uses iterative algorithms, first to synthesize the waveform covariance matrix, R, then to design the actual waveforms to realize R. In contrast to this, we present a closed form method to design R that exploits discrete Fourier transform and Toeplitz matrix. The resulting covariance matrix fulfills the practical constraints and performance is similar to that of iterative methods. Next, we present a radar architecture for the desired beampattern that does not require the synthesis of covariance matrix nor the design of correlated waveforms. © 2014 IEEE.

  6. Radar-based summer precipitation climatology of the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Bližňák, Vojtěch; Kašpar, Marek; Müller, Miloslav

    2018-01-01

    Roč. 38, č. 2 (2018), s. 677-691 ISSN 0899-8418 R&D Projects: GA ČR GA17-23773S; GA MZe QJ1520265 Institutional support: RVO:68378289 Keywords : weather radar * rain gauges * adjustment * precipitation climatology * Czech Republic Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Meteorology and atmospheric sciences Impact factor: 3.760, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/joc.5202/full

  7. A Critical Evaluation of Ground-Penetrating Radar Methodology on the Kalavasos and Maroni Built Environments (KAMBE) Project, Cyprus (Invited)

    Science.gov (United States)

    Leon, J.; Urban, T.; Gerard-Little, P.; Kearns, C.; Manning, S. W.; Fisher, K.; Rogers, M.

    2013-12-01

    at these settlements. Having just completed this first phase of the project, we report on the results of large-scale geophysical survey, including the identification of at least two previously unknown building complexes (one at each site). Here we focus particularly on ground-penetrating radar (GPR) data and survey methodology, in an effort to critically examine the range of approaches applied throughout the project (e.g. various antennae frequencies, data-collection densities, soil moisture/seasonality of survey, and post-collection data processing [2]), and to identify the most effective parameters for archaeological geophysical survey in the region. This paper also advocates for the role of geophysical survey within a multi-component archaeological project, not simply as a prospection tool but as an archaeological data collection method in its own right. 1]Fisher, K. D., J. Leon, S. Manning, M. Rogers, and D. Sewell. In Press. 2011-2012. 'The Kalavasos and Maroni Built Environments Project: Introduction and preliminary report on the 2008 and 2010 seasons. Report of the Department of Antiquities, Cyprus. 2] e.g. Rogers, M., J. F. Leon, K. D. Fisher, S. W. Manning and D. Sewell. 2012. 'Comparing similar ground-penetrating radar surveys under different soil moisture conditions at Kalavasos-Ayios Dhimitrios, Cyprus.' Archaeological Prospection 19 (4): 297-305.

  8. Transparent 3D Visualization of Archaeological Remains in Roman Site in Ankara-Turkey with Ground Penetrating Radar Method

    Science.gov (United States)

    Kadioglu, S.

    2009-04-01

    Transparent 3D Visualization of Archaeological Remains in Roman Site in Ankara-Turkey with Ground Penetrating Radar Method Selma KADIOGLU Ankara University, Faculty of Engineering, Department of Geophysical Engineering, 06100 Tandogan/ANKARA-TURKEY kadioglu@eng.ankara.edu.tr Anatolia has always been more the point of transit, a bridge between West and East. Anatolia has been a home for ideas moving from all directions. So it is that in the Roman and post-Roman periods the role of Anatolia in general and of Ancyra (the Roman name of Ankara) in particular was of the greatest importance. Now, the visible archaeological remains of Roman period in Ankara are Roman Bath, Gymnasium, the Temple of Augustus of Rome, Street, Theatre, City Defence-Wall. The Caesar Augustus, the first Roman Emperor, conquered Asia Minor in 25 BC. Then a marble temple was built in Ancyra, the administrative capital of province, today the capital of Turkish Republic, Ankara. This monument was consecrated to the Empreror and to the Goddess Rome. This temple is supposed to have built over an earlier temple dedicated to Kybele and Men between 25 -20 BC. After the death of the Augustus in 14AD, a copy of the text of "Res Gestae Divi Augusti" was inscribed on the interior of the pronaos in Latin, whereas a Greek translation is also present on an exterior wall of the cella. In the 5th century, it was converted in to a church by the Byzantines. The aim of this study is to determine old buried archaeological remains in the Augustus temple, Roman Bath and in the governorship agora in Ulus district. These remains were imaged with transparent three dimensional (3D) visualization of the ground penetrating radar (GPR) data. Parallel two dimensional (2D) GPR profile data were acquired in the study areas, and then a 3D data volume were built using parallel 2D GPR data. A simplified amplitude-colour range and appropriate opacity function were constructed and transparent 3D image were obtained to activate buried

  9. COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar": ongoing research activities and third-year results

    Science.gov (United States)

    Pajewski, Lara; Benedetto, Andrea; Loizos, Andreas; Tosti, Fabio

    2016-04-01

    This work aims at disseminating the ongoing research activities and third-year results of the COST (European COoperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar." About 350 experts are participating to the Action, from 28 COST Countries (Austria, Belgium, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Malta, Macedonia, The Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, United Kingdom), and from Albania, Armenia, Australia, Colombia, Egypt, Hong Kong, Jordan, Israel, Philippines, Russia, Rwanda, Ukraine, and United States of America. In September 2014, TU1208 has been recognised among the running Actions as "COST Success Story" ("The Cities of Tomorrow: The Challenges of Horizon 2020," September 17-19, 2014, Torino, IT - A COST strategic workshop on the development and needs of the European cities). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, whilst simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Moreover, the Action is oriented to the following specific objectives and expected deliverables: (i) coordinating European scientists to highlight problems, merits and limits of current GPR systems; (ii) developing innovative protocols and guidelines, which will be published in a handbook and constitute a basis for European standards, for an effective GPR application in civil- engineering tasks; safety, economic and financial criteria will be integrated within the protocols; (iii) integrating competences for the improvement and merging of electromagnetic scattering techniques and of data- processing techniques; this will lead to a novel freeware tool for the localization of

  10. Ground-Based Telescope Parametric Cost Model

    Science.gov (United States)

    Stahl, H. Philip; Rowell, Ginger Holmes

    2004-01-01

    A parametric cost model for ground-based telescopes is developed using multi-variable statistical analysis, The model includes both engineering and performance parameters. While diameter continues to be the dominant cost driver, other significant factors include primary mirror radius of curvature and diffraction limited wavelength. The model includes an explicit factor for primary mirror segmentation and/or duplication (i.e.. multi-telescope phased-array systems). Additionally, single variable models based on aperture diameter are derived. This analysis indicates that recent mirror technology advances have indeed reduced the historical telescope cost curve.

  11. Non Destructive Tests for Evaluation of Railway Platforms: Application of Ground Penetrating Radar

    OpenAIRE

    Fontul, S.; Fortunato, E.; Chiara, F.; Paixão, A.

    2012-01-01

    Identification and diagnosis of railway track problems of the supporting layers is essential to achieve efficient maintenance and safe train operations [1]. Nowadays, maintenance interventions consist of performing different operations such as levelling and tamping of the track, based on the measured geometric parameters. Although these actions restore the track design geometry, they do not solve substructure related problems. Thus, a better maintenance policy should be adop...

  12. Oblique Projection Polarization Filtering-Based Interference Suppressions for Radar Sensor Networks

    Directory of Open Access Journals (Sweden)

    Cao Bin

    2010-01-01

    Full Text Available The interferences coming from the radar members degrade the detection and recognition performance of the radar sensor networks (RSNs if the waveforms of the radar members are nonorthogonal. In this paper, we analyze the interferences by exploring the polarization information of the electromagnetic (EM waves. Then, we propose the oblique projection polarization filtering- (OPPF- based scheme to suppress the interferences while keeping the amplitude and phase of its own return in RSNs, even if the polarized states of the radar members are not orthogonal. We consider the cooperative RSNs environment where the polarization information of each radar member is known to all. The proposed method uses all radar members' polarization information to establish the corresponding filtering operator. The Doppler-shift and its uncertainty are independent of the polarization information, which contributes that the interferences can be suppressed without the utilization of the spatial, the temporal, the frequency, the time-delay and the Doppler-shift information. Theoretical analysis and the mathematical deduction show that the proposed scheme is a valid and simple implementation. Simulation results also demonstrate that this method can obtain a good filtering performance when dealing with the problem of interference suppressions for RSNs.

  13. Dynamic Gesture Recognition with a Terahertz Radar Based on Range Profile Sequences and Doppler Signatures.

    Science.gov (United States)

    Zhou, Zhi; Cao, Zongjie; Pi, Yiming

    2017-12-21

    The frequency of terahertz radar ranges from 0.1 THz to 10 THz, which is higher than that of microwaves. Multi-modal signals, including high-resolution range profile (HRRP) and Doppler signatures, can be acquired by the terahertz radar system. These two kinds of information are commonly used in automatic target recognition; however, dynamic gesture recognition is rarely discussed in the terahertz regime. In this paper, a dynamic gesture recognition system using a terahertz radar is proposed, based on multi-modal signals. The HRRP sequences and Doppler signatures were first achieved from the radar echoes. Considering the electromagnetic scattering characteristics, a feature extraction model is designed using location parameter estimation of scattering centers. Dynamic Time Warping (DTW) extended to multi-modal signals is used to accomplish the classifications. Ten types of gesture signals, collected from a terahertz radar, are applied to validate the analysis and the recognition system. The results of the experiment indicate that the recognition rate reaches more than 91%. This research verifies the potential applications of dynamic gesture recognition using a terahertz radar.

  14. Grounding line migration through the calving season at Jakobshavn Isbræ, Greenland, observed with terrestrial radar interferometry

    Science.gov (United States)

    Xie, Surui; Dixon, Timothy H.; Voytenko, Denis; Deng, Fanghui; Holland, David M.

    2018-04-01

    Ice velocity variations near the terminus of Jakobshavn Isbræ, Greenland, were observed with a terrestrial radar interferometer (TRI) during three summer campaigns in 2012, 2015, and 2016. We estimate a ˜ 1 km wide floating zone near the calving front in early summer of 2015 and 2016, where ice moves in phase with ocean tides. Digital elevation models (DEMs) generated by the TRI show that the glacier front here was much thinner (within 1 km of the glacier front, average ice surface is ˜ 100 and ˜ 110 m above local sea level in 2015 and 2016, respectively) than ice upstream (average ice surface is > 150 m above local sea level at 2-3 km to the glacier front in 2015 and 2016). However, in late summer 2012, there is no evidence of a floating ice tongue in the TRI observations. Average ice surface elevation near the glacier front was also higher, ˜ 125 m above local sea level within 1 km of the glacier front. We hypothesize that during Jakobshavn Isbræ's recent calving seasons the ice front advances ˜ 3 km from winter to spring, forming a > 1 km long floating ice tongue. During the subsequent calving season in mid- and late summer, the glacier retreats by losing its floating portion through a sequence of calving events. By late summer, the entire glacier is likely grounded. In addition to ice velocity variation driven by tides, we also observed a velocity variation in the mélange and floating ice front that is non-parallel to long-term ice flow motion. This cross-flow-line signal is in phase with the first time derivative of tidal height and is likely associated with tidal currents or bed topography.

  15. Long-term sequential monitoring of controlled graves representing common burial scenarios with ground penetrating radar: Years 2 and 3

    Science.gov (United States)

    Schultz, John J.; Walter, Brittany S.; Healy, Carrie

    2016-09-01

    Geophysical techniques such as ground-penetrating radar (GPR) have been successfully used for forensic searches to locate clandestine graves and physical evidence. However, additional controlled research is needed to fully understand the applicability of this technology when searching for clandestine graves in various environments, soil types, and for longer periods of time post-burial. The purpose of this study was to determine the applicability of GPR for detecting controlled graves in a Spodosol representing multiple burial scenarios for Years 2 and 3 of a three-year monitoring period. Objectives included determining how different burial scenarios are factors in producing a distinctive anomalous response; determining how different GPR imagery options (2D reflection profiles and horizontal time slices) can provide increased visibility of the burials; and comparing GPR imagery between 500 MHz and 250 MHz dominant frequency antennae. The research site contained a grid with eight graves representing common forensic burial scenarios in a Spodosol, a common soil type of Florida, with six graves containing a pig carcass (Sus scrofa). Burial scenarios with grave items (a deep grave with a layer of rocks over the carcass and a carcass wrapped in a tarpaulin) produced a more distinctive response with clearer target reflections over the duration of the monitoring period compared to naked carcasses. Months with increased precipitation were also found to produce clearer target reflections than drier months, particularly during Year 3 when many grave scenarios that were not previously visible became visible after increased seasonal rainfall. Overall, the 250 MHz dominant frequency antenna imagery was more favorable than the 500 MHz. While detection of a simulated grave may be difficult to detect over time, long term detection of a grave in a Spodosol may be possible if the disturbed spodic horizon is detected. Furthermore, while grave visibility increased with the 2D

  16. Ground-penetrating radar (GPR) responses for sub-surface salt contamination and solid waste: modeling and controlled lysimeter studies.

    Science.gov (United States)

    Wijewardana, Y N S; Shilpadi, A T; Mowjood, M I M; Kawamoto, K; Galagedara, L W

    2017-02-01

    The assessment of polluted areas and municipal solid waste (MSW) sites using non-destructive geophysical methods is timely and much needed in the field of environmental monitoring and management. The objectives of this study are (i) to evaluate the ground-penetrating radar (GPR) wave responses as a result of different electrical conductivity (EC) in groundwater and (ii) to conduct MSW stratification using a controlled lysimeter and modeling approach. A GPR wave simulation was carried out using GprMax2D software, and the field test was done on two lysimeters that were filled with sand (Lysimeter-1) and MSW (Lysimeter-2). A Pulse EKKO-Pro GPR system with 200- and 500-MHz center frequency antennae was used to collect GPR field data. Amplitudes of GPR-reflected waves (sub-surface reflectors and water table) were studied under different EC levels injected to the water table. Modeling results revealed that the signal strength of the reflected wave decreases with increasing EC levels and the disappearance of the subsurface reflection and wave amplitude reaching zero at higher EC levels (when EC >0.28 S/m). Further, when the EC level was high, the plume thickness did not have a significant effect on the amplitude of the reflected wave. However, it was also found that reflected signal strength decreases with increasing plume thickness at a given EC level. 2D GPR profile images under wet conditions showed stratification of the waste layers and relative thickness, but it was difficult to resolve the waste layers under dry conditions. These results show that the GPR as a non-destructive method with a relatively larger sample volume can be used to identify highly polluted areas with inorganic contaminants in groundwater and waste stratification. The current methods of MSW dumpsite investigation are tedious, destructive, time consuming, costly, and provide only point-scale measurements. However, further research is needed to verify the results under heterogeneous aquifer

  17. Estimation of the near surface soil water content during evaporation using air-launched ground-penetrating radar

    KAUST Repository

    Moghadas, Davood

    2014-01-01

    Evaporation is an important process in the global water cycle and its variation affects the near sur-face soil water content, which is crucial for surface hydrology and climate modelling. Soil evaporation rate is often characterized by two distinct phases, namely, the energy limited phase (stage-I) and the soil hydraulic limited period (stage-II). In this paper, a laboratory experiment was conducted using a sand box filled with fine sand, which was subject to evaporation for a period of twenty three days. The setup was equipped with a weighting system to record automatically the weight of the sand box with a constant time-step. Furthermore, time-lapse air-launched ground penetrating radar (GPR) measurements were performed to monitor the evaporation process. The GPR model involves a full-waveform frequency-domain solution of Maxwell\\'s equations for wave propagation in three-dimensional multilayered media. The accuracy of the full-waveform GPR forward modelling with respect to three different petrophysical models was investigated. Moreover, full-waveform inversion of the GPR data was used to estimate the quantitative information, such as near surface soil water content. The two stages of evaporation can be clearly observed in the radargram, which indicates qualitatively that enough information is contained in the GPR data. The full-waveform GPR inversion allows for accurate estimation of the near surface soil water content during extended evaporation phases, when a wide frequency range of GPR (0.8-5.0 GHz) is taken into account. In addition, the results indicate that the CRIM model may constitute a relevant alternative in solving the frequency-dependency issue for full waveform GPR modelling.

  18. Collection, processing, and interpretation of ground-penetrating radar data to determine sediment thickness at selected locations in Deep Creek Lake, Garrett County, Maryland, 2007

    Science.gov (United States)

    Banks, William S.L.; Johnson, Carole D.

    2011-01-01

    The U.S. Geological Survey collected geophysical data in Deep Creek Lake in Garrett County, Maryland, between September 17 through October 4, 2007 to assist the Maryland Department of Natural Resources to better manage resources of the Lake. The objectives of the geophysical surveys were to provide estimates of sediment thickness in shallow areas around the Lake and to test the usefulness of three geophysical methods in this setting. Ground-penetrating radar (GPR), continuous seismic-reflection profiling (CSP), and continuous resistivity profiling (CRP) were attempted. Nearly 90 miles of GPR radar data and over 70 miles of CSP data were collected throughout the study area. During field deployment and testing, CRP was determined not to be practical and was not used on a large scale. Sediment accumulation generally could be observed in the radar profiles in the shallow coves. In some seismic profiles, a thin layer of sediment could be observed at the water bottom. The radar profiles appeared to be better than the seismic profiles for the determination of sediment thickness. Although only selected data profiles were processed, all data were archived for future interpretation.

  19. Estimating belowground carbon stocks in isolated wetlands of the Northern Everglades Watershed, central Florida, using ground penetrating radar (GPR) and aerial imagery

    Science.gov (United States)

    McClellan, Matthew; Comas, Xavier; Hinkle, Ross; Sumner, David M.

    2017-01-01

    Peat soils store a large fraction of the global soil carbon (C) pool and comprise 95% of wetland C stocks. While isolated freshwater wetlands in temperate and tropical biomes account for more than 20% of the global peatland C stock, most studies of wetland soil C have occurred in expansive peatlands in northern boreal and subarctic biomes. Furthermore, the contribution of small depressional wetlands in comparison to larger wetland systems in these environments is very uncertain. Given the fact that these wetlands are numerous and variable in terms of their internal geometry, innovative methods are needed for properly estimating belowground C stocks and their overall C contribution to the landscape. In this study, we use a combination of ground penetrating radar (GPR), aerial imagery, and direct measurements (coring) in conjunction with C core analysis to develop a relation between C stock and surface area, and estimate the contribution of subtropical depressional wetlands to the total C stock of pine flatwoods at the Disney Wilderness Preserve (DWP), Florida. Additionally, GPR surveys were able to image collapse structures underneath the peat basin of depressional wetlands, depicting lithological controls on the formation of depressional wetlands at the DWP. Results indicate the importance of depressional wetlands as critical contributors to the landscape C budget at the DWP and the potential of GPR-based approaches for (1) rapidly and noninvasively estimating the contribution of depressional wetlands to regional C stocks and (2) evaluating the formational processes of depressional wetlands.

  20. Estimating Belowground Carbon Stocks in Isolated Wetlands of the Northern Everglades Watershed, Central Florida, Using Ground Penetrating Radar and Aerial Imagery

    Science.gov (United States)

    McClellan, Matthew; Comas, Xavier; Benscoter, Brian; Hinkle, Ross; Sumner, David

    2017-11-01

    Peat soils store a large fraction of the global soil carbon (C) pool and comprise 95% of wetland C stocks. While isolated freshwater wetlands in temperate and tropical biomes account for more than 20% of the global peatland C stock, most studies of wetland soil C have occurred in expansive peatlands in northern boreal and subarctic biomes. Furthermore, the contribution of small depressional wetlands in comparison to larger wetland systems in these environments is very uncertain. Given the fact that these wetlands are numerous and variable in terms of their internal geometry, innovative methods are needed for properly estimating belowground C stocks and their overall C contribution to the landscape. In this study, we use a combination of ground penetrating radar (GPR), aerial imagery, and direct measurements (coring) in conjunction with C core analysis to develop a relation between C stock and surface area, and estimate the contribution of subtropical depressional wetlands to the total C stock of pine flatwoods at the Disney Wilderness Preserve (DWP), Florida. Additionally, GPR surveys were able to image collapse structures underneath the peat basin of depressional wetlands, depicting lithological controls on the formation of depressional wetlands at the DWP. Results indicate the importance of depressional wetlands as critical contributors to the landscape C budget at the DWP and the potential of GPR-based approaches for (1) rapidly and noninvasively estimating the contribution of depressional wetlands to regional C stocks and (2) evaluating the formational processes of depressional wetlands.

  1. Estimating porosity and solid dielectric permittivity in the Miami Limestone using high-frequency ground penetrating radar (GPR) measurements at the laboratory scale

    Science.gov (United States)

    Mount, Gregory J.; Comas, Xavier

    2014-10-01

    Subsurface water flow in South Florida is largely controlled by the heterogeneous nature of the karst limestone in the Biscayne aquifer and its upper formation, the Miami Limestone. These heterogeneities are amplified by dissolution structures that induce changes in the aquifer's material and physical properties (i.e., porosity and dielectric permittivity) and create preferential flow paths. Understanding such patterns are critical for the development of realistic groundwater flow models, particularly in the Everglades, where restoration of hydrological conditions is intended. In this work, we used noninvasive ground penetrating radar (GPR) to estimate the spatial variability in porosity and the dielectric permittivity of the solid phase of the limestone at centimeter-scale resolution to evaluate the potential for field-based GPR studies. A laboratory setup that included high-frequency GPR measurements under completely unsaturated and saturated conditions was used to estimate changes in electromagnetic wave velocity through Miami Limestone samples. The Complex Refractive Index Model was used to derive estimates of porosity and dielectric permittivity of the solid phase of the limestone. Porosity estimates of the samples ranged between 45.2 and 66.0% and showed good correspondence with estimates of porosity using analytical and digital image techniques. Solid dielectric permittivity values ranged between 7.0 and 13.0. This study shows the ability of GPR to image the spatial variability of porosity and dielectric permittivity in the Miami Limestone and shows potential for expanding these results to larger scales and other karst aquifers.

  2. Use of ground-based wind profiles in mesoscale forecasting

    Science.gov (United States)

    Schlatter, Thomas W.

    1985-01-01

    A brief review is presented of recent uses of ground-based wind profile data in mesoscale forecasting. Some of the applications are in real time, and some are after the fact. Not all of the work mentioned here has been published yet, but references are given wherever possible. As Gage and Balsley (1978) point out, sensitive Doppler radars have been used to examine tropospheric wind profiles since the 1970's. It was not until the early 1980's, however, that the potential contribution of these instruments to operational forecasting and numerical weather prediction became apparent. Profiler winds and radiosonde winds compare favorably, usually within a few m/s in speed and 10 degrees in direction (see Hogg et al., 1983), but the obvious advantage of the profiler is its frequent (hourly or more often) sampling of the same volume. The rawinsonde balloon is launched only twice a day and drifts with the wind. In this paper, I will: (1) mention two operational uses of data from a wind profiling system developed jointly by the Wave Propagation and Aeronomy Laboratories of NOAA; (2) describe a number of displays of these same data on a workstation for mesoscale forecasting developed by the Program for Regional Observing and Forecasting Services (PROFS); and (3) explain some interesting diagnostic calculations performed by meteorologists of the Wave Propagation Laboratory.

  3. Sounding Cratonic Fill in Small Buried Craters Using Ground Penetrating Radar: Analog Study to the Martian Case

    OpenAIRE

    Heggy , Essam; Paillou , Philippe

    2006-01-01

    We report results from a 270 MHz GPR survey performed on a recently discovered impact field in the southwestern Egyptian desert. The investigation suggests the ability of radar techniques to detect small-buried craters and probe their filling

  4. Calibration of Ground-based Lidar instrument

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Gómez Arranz, Paula

    This report presents the result of the lidar calibration performed for the given Ground-based Lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from wind vanes...

  5. Residual translation compensations in radar target narrowband imaging based on trajectory information

    Science.gov (United States)

    Yue, Wenjue; Peng, Bo; Wei, Xizhang; Li, Xiang; Liao, Dongping

    2018-05-01

    High velocity translation will result in defocusing scattering centers in radar imaging. In this paper, we propose a Residual Translation Compensations (RTC) method based on target trajectory information to eliminate the translation effects in radar imaging. Translation could not be simply regarded as a uniformly accelerated motion in reality. So the prior knowledge of the target trajectory is introduced to enhance compensation precision. First we use the two-body orbit model to figure out the radial distance. Then, stepwise compensations are applied to eliminate residual propagation delay based on conjugate multiplication method. Finally, tomography is used to confirm the validity of the method. Compare with translation parameters estimation method based on the spectral peak of the conjugate multiplied signal, RTC method in this paper enjoys a better tomography result. When the Signal Noise Ratio (SNR) of the radar echo signal is 4dB, the scattering centers can also be extracted clearly.

  6. Spatial Variability of accumulation across the Western Greenland Ice Sheet Percolation Zone from ground-penetrating-radar and shallow firn cores

    Science.gov (United States)

    Lewis, G.; Osterberg, E. C.; Hawley, R. L.; Marshall, H. P.; Birkel, S. D.; Meehan, T. G.; Graeter, K.; Overly, T. B.; McCarthy, F.

    2017-12-01

    The mass balance of the Greenland Ice Sheet (GrIS) in a warming climate is of critical interest to scientists and the general public in the context of future sea-level rise. Increased melting in the GrIS percolation zone over the past several decades has led to increased mass loss at lower elevations due to recent warming. Uncertainties in mass balance are especially large in regions with sparse and/or outdated in situ measurements. This study is the first to calculate in situ accumulation over a large region of western Greenland since the Program for Arctic Regional Climate Assessment campaign during the 1990s. Here we analyze 5000 km of 400 MHz ground penetrating radar data and sixteen 25-33 m-long firn cores in the western GrIS percolation zone to determine snow accumulation over the past 50 years. The cores and radar data were collected as part of the 2016-2017 Greenland Traverse for Accumulation and Climate Studies (GreenTrACS). With the cores and radar profiles we capture spatial accumulation gradients between 1850-2500 m a.s.l and up to Summit Station. We calculate accumulation rates and use them to validate five widely used regional climate models and to compare with IceBridge snow and accumulation radars. Our results indicate that while the models capture most regional spatial climate patterns, they lack the small-scale spatial variability captured by in situ measurements. Additionally, we evaluate temporal trends in accumulation at ice core locations and throughout the traverse. Finally, we use empirical orthogonal function and correlation analyses to investigate the principal drivers of radar-derived accumulation rates across the western GrIS percolation zone, including major North Atlantic climate modes such as the North Atlantic Oscillation, Atlantic Multidecadal Oscillation, and Greenland Blocking Index.

  7. Radar-based rainfall estimation: Improving Z/R relations through comparison of drop size distributions, rainfall rates and radar reflectivity patterns

    Science.gov (United States)

    Neuper, Malte; Ehret, Uwe

    2014-05-01

    The relation between the measured radar reflectivity factor Z and surface rainfall intensity R - the Z/R relation - is profoundly complex, so that in general one speaks about radar-based quantitative precipitation estimation (QPE) rather than exact measurement. Like in Plato's Allegory of the Cave, what we observe in the end is only the 'shadow' of the true rainfall field through a very small backscatter of an electromagnetic signal emitted by the radar, which we hope has been actually reflected by hydrometeors. The meteorological relevant and valuable Information is gained only indirectly by more or less justified assumptions. One of these assumptions concerns the drop size distribution, through which the rain intensity is finally associated with the measured radar reflectivity factor Z. The real drop size distribution is however subject to large spatial and temporal variability, and consequently so is the true Z/R relation. Better knowledge of the true spatio-temporal Z/R structure therefore has the potential to improve radar-based QPE compared to the common practice of applying a single or a few standard Z/R relations. To this end, we use observations from six laser-optic disdrometers, two vertically pointing micro rain radars, 205 rain gauges, one rawindsonde station and two C-band Doppler radars installed or operated in and near the Attert catchment (Luxembourg). The C-band radars and the rawindsonde station are operated by the Belgian and German Weather Services, the rain gauge data was partly provided by the French, Dutch, Belgian, German Weather Services and the Ministry of Agriculture of Luxembourg and the other equipment was installed as part of the interdisciplinary DFG research project CAOS (Catchment as Organized Systems). With the various data sets correlation analyzes were executed. In order to get a notion on the different appearance of the reflectivity patterns in the radar image, first of all various simple distribution indices (for example the

  8. Space weather effects on ground based technology

    Science.gov (United States)

    Clark, T.

    Space weather can affect a variety of forms of ground-based technology, usually as a result of either the direct effects of the varying geomagnetic field, or as a result of the induced electric field that accompanies such variations. Technologies affected directly by geomagnetic variations include magnetic measurements made d ringu geophysical surveys, and navigation relying on the geomagnetic field as a direction reference, a method that is particularly common in the surveying of well-bores in the oil industry. The most obvious technology affected by induced electric fields during magnetic storms is electric power transmission, where the example of the blackout in Quebec during the March 1989 magnetic storm is widely known. Additionally, space weather effects must be taken into account in the design of active cathodic protection systems on pipelines to protect them against corrosion. Long-distance telecommunication cables may also have to be designed to cope with space weather related effects. This paper reviews the effects of space weather in these different areas of ground-based technology, and provides examples of how mitigation against hazards may be achieved. (The paper does not include the effects of space weather on radio communication or satellite navigation systems).

  9. Generic framework for vessel detection and tracking based on distributed marine radar image data

    Science.gov (United States)

    Siegert, Gregor; Hoth, Julian; Banyś, Paweł; Heymann, Frank

    2018-04-01

    Situation awareness is understood as a key requirement for safe and secure shipping at sea. The primary sensor for maritime situation assessment is still the radar, with the AIS being introduced as supplemental service only. In this article, we present a framework to assess the current situation picture based on marine radar image processing. Essentially, the framework comprises a centralized IMM-JPDA multi-target tracker in combination with a fully automated scheme for track management, i.e., target acquisition and track depletion. This tracker is conditioned on measurements extracted from radar images. To gain a more robust and complete situation picture, we are exploiting the aspect angle diversity of multiple marine radars, by fusing them a priori to the tracking process. Due to the generic structure of the proposed framework, different techniques for radar image processing can be implemented and compared, namely the BLOB detector and SExtractor. The overall framework performance in terms of multi-target state estimation will be compared for both methods based on a dedicated measurement campaign in the Baltic Sea with multiple static and mobile targets given.

  10. Drone Detection with Chirp‐Pulse Radar Based on Target Fluctuation Models

    Directory of Open Access Journals (Sweden)

    Byung‐Kwan Kim

    2018-04-01

    Full Text Available This paper presents a pulse radar system to detect drones based on a target fluctuation model, specifically the Swerling target model. Because drones are small atypical objects and are mainly composed of non‐conducting materials, their radar cross‐section value is low and fluctuating. Therefore, determining the target fluctuation model and applying a proper integration method are important. The proposed system is herein experimentally verified and the results are discussed. A prototype design of the pulse radar system is based on radar equations. It adopts three different pulse modes and a coherent pulse integration to ensure a high signal‐to‐noise ratio. Outdoor measurements are performed with a prototype radar system to detect Doppler frequencies from both the drone frame and blades. The results indicate that the drone frame and blades are detected within an instrumental maximum range. Additionally, the results show that the drone's frame and blades are close to the Swerling 3 and 4 target models, respectively. By the analysis of the Swerling target models, proper integration methods for detecting drones are verified and can thus contribute to increasing in detectability.

  11. Comparison of classification algorithms for various methods of preprocessing radar images of the MSTAR base

    Science.gov (United States)

    Borodinov, A. A.; Myasnikov, V. V.

    2018-04-01

    The present work is devoted to comparing the accuracy of the known qualification algorithms in the task of recognizing local objects on radar images for various image preprocessing methods. Preprocessing involves speckle noise filtering and normalization of the object orientation in the image by the method of image moments and by a method based on the Hough transform. In comparison, the following classification algorithms are used: Decision tree; Support vector machine, AdaBoost, Random forest. The principal component analysis is used to reduce the dimension. The research is carried out on the objects from the base of radar images MSTAR. The paper presents the results of the conducted studies.

  12. Combined radar and telemetry system

    Energy Technology Data Exchange (ETDEWEB)

    Rodenbeck, Christopher T.; Young, Derek; Chou, Tina; Hsieh, Lung-Hwa; Conover, Kurt; Heintzleman, Richard

    2017-08-01

    A combined radar and telemetry system is described. The combined radar and telemetry system includes a processing unit that executes instructions, where the instructions define a radar waveform and a telemetry waveform. The processor outputs a digital baseband signal based upon the instructions, where the digital baseband signal is based upon the radar waveform and the telemetry waveform. A radar and telemetry circuit transmits, simultaneously, a radar signal and telemetry signal based upon the digital baseband signal.

  13. Recent successes and emerging challenges for coordinated satellite/ground-based magnetospheric exploration and modeling.

    Science.gov (United States)

    Angelopoulos, Vassilis

    With the availability of a distributed constellation of spacecraft (THEMIS, Geotail, Cluster) and increased capability ground based arrays (SuperDARN, THEMIS/GBOs), it is now pos-sible to infer simply from timing significant information regarding mapping of magnetospheric phenomena. Optical, magnetometer and radar data can pinpoint the location and nature of onset signatures. On the other hand, magnetic field modeling constrained by physical bound-aries (such as the isotropy boundary) the measured magnetic field and total pressure values at a distibuted network of satellites has proven to do a much better job at correlating ionospheric precipitation and diffuse auroral boundaries to magnetospheric phenomena, such as the inward boundary of the dipolarization fronts. It is now possible to routinely compare in-situ measured phase space densities of ion and electron distributions during ionosphere -magnetosphere con-junctions, in the absense of potential drops. It is also possible to not only infer equivalent current systems from the ground, but use reconstruction of the ionospheric current system from space to determine the full electrodynamics evolution of the ionosphere and compare with radars. Assimilation of this emerging ground based and global magnetospheric panoply into a self consistent magnetospheric model will likely be one of the most fruitful endeavors in magnetospheric exploration during the next few years.

  14. Design and Implementation of a FPGA and DSP Based MIMO Radar Imaging System

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2015-06-01

    Full Text Available The work presented in this paper is aimed at the implementation of a real-time multiple-input multiple-output (MIMO imaging radar used for area surveillance. In this radar, the equivalent virtual array method and time-division technique are applied to make 16 virtual elements synthesized from the MIMO antenna array. The chirp signal generater is based on a combination of direct digital synthesizer (DDS and phase locked loop (PLL. A signal conditioning circuit is used to deal with the coupling effect within the array. The signal processing platform is based on an efficient field programmable gates array (FPGA and digital signal processor (DSP pipeline where a robust beamforming imaging algorithm is running on. The radar system was evaluated through a real field experiment. Imaging capability and real-time performance shown in the results demonstrate the practical feasibility of the implementation.

  15. Wire-grid electromagnetic modelling of metallic cylindrical objects with arbitrary section, for Ground Penetrating Radar applications

    Science.gov (United States)

    Adabi, Saba; Pajewski, Lara

    2014-05-01

    Authors demonstrated that the well-known same-area criterion yields affordable results but is quite far from being the optimum: better results can be obtained with a wire radius shorter than what is suggested by the rule. In utility detection, quality controls of reinforced concrete, and other civil-engineering applications, many sought targets are long and thin: in these cases, two-dimensional scattering methods can be employed for the electromagnetic modelling of scenarios. In the present work, the freeware tool GPRMAX2D [6], implementing the Finite-Difference Time-Domain method, is used to implement the wire-grid modelling of buried two-dimensional objects. The source is a line of current, with Ricker waveform. Results obtained in [5] are confirmed in the time domain and for different geometries. The highest accuracy is obtained by shortening the radius of about 10%. It seems that fewer (and larger) wires need minor shortening; however, more detailed investigations are required. We suggest to use at least 8 - 10 wires per wavelength if the field scattered by the structure has to be evaluated. The internal field is much more sensitive to the modelling configuration than the external one, and more wires should be employed when shielding effects are concerned. We plan to conduct a more comprehensive analysis, in order to extract guidelines for wire sizing, to be validated on different shapes. We also look forward to verifying the possibility of using the wire-grid modelling method for the simulation of slotted objects. This work is a contribution to COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar". The Authors thanks COST for funding COST Action TU1208. References [1] J.H. Richmond, A wire grid model for scattering by conducting bodies, IEEE Trans. Antennas Propagation AP-14 (1966), pp. 782-786. [2] S.M. Rao, D.R. Wilton, A.W. Glisson, Electromagnetic scattering by surfaces of arbitrary shape, IEEE Trans. Antennas Propagation AP-30 (1982

  16. THE DECENNIAL OF AIR FORCE SPACE COMMAND’S ONLY GROUND BASED MISSILE WARNING CLASSIC ASSOCIATE UNIT: BENEFITS, DRAWBACKS, AND CHALLENGES

    Science.gov (United States)

    2016-02-16

    Fulfillment of the Graduation Requirements Proposal Adviser: Dr. Patricia Lessane Project Advisor: Dr. Gregory F. Intoccia Maxwell Air Force Base, Alabama... SBIRS ), and Ground Based Missile Warning Radars (GBMWR). 7 In unison, these assets monitor ballistic missile launches and help prevent surprise

  17. The Application of Ground-Penetrating Radar to Transportation Engineering: Recent Advances and New Perspectives (GI Division Outstanding ECS Award Lecture)

    Science.gov (United States)

    Tosti, Fabio; Benedetto, Andrea; Pajewski, Lara; Alani, Amir M.

    2017-04-01

    Ground-penetrating radar (GPR) is one of the most acknowledged and established non-destructive testing (NDT) techniques within the context of the health monitoring and assessment of transportation infrastructures. GPR is being increasingly used for the effective management of infrastructural assets as it weakens the case for using other destructive monitoring methods, such as digging holes, and allows for rapid and reliable detection of many causes of the subsurface damage. Thereby, its usage favours the optimisation of the economical expenditure for the effective maintenance of great infrastructures as well as it improves the public safety by preventing or not raising the risk of accidents. GPR has been used in highway, railway and airfield engineering as well as for the monitoring of critical infrastructures, such as bridges and tunnels. It has found established use in the assessment of the geometric properties of the subsurface, such as in the case of the evaluation of the pavement layer thicknesses, or the size of the rebars in concrete-made structural components. Major physical-based investigations have been focused on the evaluation of the moisture ingress in flexible road pavements and in concrete structures, as well as on the detection of the rebars corrosion caused by the ingress of chloride. The majority of these parameters are evaluated using methods of signal analysis and data processing based on the signal in the time domain. The sophistication of the hardware and software of the GPR systems over the last few years as well as the recent advances achieved in the research have contributed to raise the high potential of this non-destructive technique and paved the way towards new application areas in transportation engineering. In particular, GPR is nowadays finding major application when used with complementary non-destructive testing techniques, although it has still proved to provide reliable results in various self-standing applications. This work

  18. Ground-Penetrating Radar Study of Fort Morgan Peninsula Holocene Beach Ridges as Sea-level Indicators

    Science.gov (United States)

    Philbin, A.; Frederick, B.; Blum, M. D.; Tsoflias, G. P.

    2017-12-01

    Holocene sea-level change along the northern Gulf of Mexico (GoM) coast is controversial. One view interprets basal peats from the Mississippi Delta to indicate continual sea-level (SL) rise for the GoM as a whole. An alternate view proposes that data from the subsiding delta is primarily a subsidence signal, and that sandy non-deltaic shorelines indicate that regional SL reached present elevations by the middle Holocene, with minor oscillations since then. In fact, new regional long-term subsidence records from biostratigraphic indicators display significant subsidence in deltaic areas where basal-peat data were collected, and negligible rates along the GoM shoreline to the east. However, the use of sandy progradational shorelines, commonly known as "beach ridge systems", has been criticized for a lack of precise sea-level indicators, and therefore discounted. This research focuses on developing Holocene progradational sandy shorelines along the Alabama coast in the eastern GoM as SL indicators. Sandy shorelines in this area are ideal to examine SL change because they are well preserved, sufficiently distant from the subsiding delta, well mapped, and ages are known from previous work. Two-dimensional ground-penetrating radar imaging of well-dated beach-ridge successions is used here to examine and identify changes through time in the elevation of the shoreface clinoform topset-foreset break, which represents the transition between flat-lying foreshore and seaward-dipping shoreface facies, and forms in the intertidal zone. Beach-ridge successions with optical luminescence ages of ca. 5500-4800 yrs BP display topset-foreset breaks at current mean sea-level elevation, whereas beach-ridge successions from ca. 3500-2400 yrs BP display topset-foreset breaks that are 1 m above present mean SL and the elevation of modern topset-foreset breaks. These data support the view that current sea-level was reached by the middle Holocene, and was higher than present for at least

  19. Joint application of ground penetrating radar and electrical resistivity measurements for characterization of subsurface stratigraphy in Southwestern Nigeria

    International Nuclear Information System (INIS)

    Adepelumi, A A; Fayemi, O

    2012-01-01

    The frequent building collapses in Nigeria have been attributed to a lack of pre-construction investigations, which assist engineers in obtaining in situ geotechnical information. Further, the structural subsurface settings are often ignored or investigation is haphazardly carried out. To address this issue and demonstrate the importance of such a survey, a combination of ground penetrating radar (GPR) and vertical electrical sounding (VES) data were acquired in a part of Southwestern Nigeria. A 200 MHz antenna was used for the data acquisition along four traverses. The data were subjected to standard GPR processing techniques, and attribute analysis such as instantaneous frequency, amplitude and phase. Also, for comparative and engineering characterization purposes, longitudinal conductance and coefficient of anisotropy were computed from the VES results and used for determining the competency of the bedrocks. From the GPR results, it was observed that the mapped subsurface is characterized as erosional truncated at a low angle, which is southerly dipping and includes tangential reflections. Further, stratified rocks dipping at an angle of 32° occur between 1.0 and 4.5 m depth in all of the GPR sections; these strata were truncated by topsoil at shallow depths. Also, some of the sections depict ancient channel structures that have a dimension of 70 m × 40 m. The resistivity data suggest that the study area is characterized by four distinct geoelectric sequences. These comprise topsoil which is composed of clay-like sand to lateritic clay whose thickness ranges between 0.25 and 8.12 m, weathered bedrock with a thickness between 3.84 and 12.61 m, stratified bedrock with a thickness between 0.33 and 7.51 m, and fresh bedrock. These results reveal a complex subsurface geology and this characterizes the study area. The area has low to moderate longitudinal conductance and coefficient of anisotropy values, which suggest that incompetent to semi-competent bedrock

  20. The Use of Ground Penetrating Radar and Electrical Resistivity Imaging for the Characterisation of Slope Movements in Expansive Marls

    Science.gov (United States)

    Rey, Isabel; Martínez, Julián; Cortada, Unai; Hildago, Mª Carmen

    2017-04-01

    Slope movements are one of the natural hazards that most affect linear projects, becoming an important waste of money and time for building companies. Thus, studies to identify the processes that provoke these movements, as well as to characterise the landslides are necessary. For this purpose, geophysical prospecting techniques as Ground Penetrating Radar (GPR) and Electrical Resistivity Imaging (ERI) could become useful. However, the effectiveness of these techniques in slope movement characterisation is affected by many factors, like soil humidity, grain size or failure plane depth. Therefore, studies that determine the usefulness of these techniques in different kind of soils and slope movements are required. In this study, GPR and ERI techniques efficiency for the analysis of slope movements in Upper Miocene expansive marls was evaluated. In particular, two landslides in an old regional road in the province of Jaen (Spain) were studied. A total of 53 GPR profiles were made, 31 with a 250 MHz frequency antenna and 22 with an 800 MHz frequency antenna. Marl facies rapidly attenuated the signal of the electromagnetic waves, which means that this technique only provided information of the first two meters of the subsoil. In spite of this low depth of penetration, it is necessary to point out the precision and detail undertaken. Thus, both GPR antennas gave information of the thicknesses and quality-continuity of the different soil layers. In addition, several restoration phases of the linear work were detected. Therefore, this technique was useful to detect the current state and history of the structure, even though it could not detect the shear surface of the slope movement. On the other hand, two profiles of electrical tomography were made, one in each studied sector. The profiles were configured with a total length of 189 m, with 64 electrodes and a spacing of 3 m. This allowed investigating up to 35 m depth. This penetration capability enabled to detect the

  1. Detecting and mitigating wind turbine clutter for airspace radar systems.

    Science.gov (United States)

    Wang, Wen-Qin

    2013-01-01

    It is well recognized that a wind turbine has a large radar cross-section (RCS) and, due to the movement of the blades, the wind turbine will generate a Doppler frequency shift. This scattering behavior may cause severe interferences on existing radar systems including static ground-based radars and spaceborne or airborne radars. To resolve this problem, efficient techniques or algorithms should be developed to mitigate the effects of wind farms on radars. Herein, one transponder-based mitigation technique is presented. The transponder is not a new concept, which has been proposed for calibrating high-resolution imaging radars. It modulates the radar signal in a manner that the retransmitted signals can be separated from the scene echoes. As wind farms often occupy only a small area, mitigation processing in the whole radar operation will be redundant and cost inefficient. Hence, this paper uses a transponder to determine whether the radar is impacted by the wind farms. If so, the effects of wind farms are then mitigated with subsequent Kalman filtering or plot target extraction algorithms. Taking airborne synthetic aperture radar (SAR) and pulse Doppler radar as the examples, this paper provides the corresponding system configuration and processing algorithms. The effectiveness of the mitigation technique is validated by numerical simulation results.

  2. Detecting and Mitigating Wind Turbine Clutter for Airspace Radar Systems

    Directory of Open Access Journals (Sweden)

    Wen-Qin Wang

    2013-01-01

    Full Text Available It is well recognized that a wind turbine has a large radar cross-section (RCS and, due to the movement of the blades, the wind turbine will generate a Doppler frequency shift. This scattering behavior may cause severe interferences on existing radar systems including static ground-based radars and spaceborne or airborne radars. To resolve this problem, efficient techniques or algorithms should be developed to mitigate the effects of wind farms on radars. Herein, one transponder-based mitigation technique is presented. The transponder is not a new concept, which has been proposed for calibrating high-resolution imaging radars. It modulates the radar signal in a manner that the retransmitted signals can be separated from the scene echoes. As wind farms often occupy only a small area, mitigation processing in the whole radar operation will be redundant and cost inefficient. Hence, this paper uses a transponder to determine whether the radar is impacted by the wind farms. If so, the effects of wind farms are then mitigated with subsequent Kalman filtering or plot target extraction algorithms. Taking airborne synthetic aperture radar (SAR and pulse Doppler radar as the examples, this paper provides the corresponding system configuration and processing algorithms. The effectiveness of the mitigation technique is validated by numerical simulation results.

  3. SCIENTIFIC EFFICIENCY OF GROUND-BASED TELESCOPES

    International Nuclear Information System (INIS)

    Abt, Helmut A.

    2012-01-01

    I scanned the six major astronomical journals of 2008 for all 1589 papers that are based on new data obtained from ground-based optical/IR telescopes worldwide. Then I collected data on numbers of papers, citations to them in 3+ years, the most-cited papers, and annual operating costs. These data are assigned to four groups by telescope aperture. For instance, while the papers from telescopes with an aperture >7 m average 1.29 more citations than those with an aperture of 2 to 7 m) telescopes. I wonder why the large telescopes do so relatively poorly and suggest possible reasons. I also found that papers based on archival data, such as the Sloan Digital Sky Survey, produce 10.6% as many papers and 20.6% as many citations as those based on new data. Also, the 577.2 papers based on radio data produced 36.3% as many papers and 33.6% as many citations as the 1589 papers based on optical/IR telescopes.

  4. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    KAUST Repository

    Jadoon, Khan

    2015-09-18

    We tested an off-ground ground-penetrating radar (GPR) system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  5. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    KAUST Repository

    Jadoon, Khan; Weihermller, Lutz; McCabe, Matthew; Moghadas, Davood; Vereecken, Harry; Lambot, Sbastien

    2015-01-01

    We tested an off-ground ground-penetrating radar (GPR) system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  6. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Khan Zaib Jadoon

    2015-09-01

    Full Text Available We tested an off-ground ground-penetrating radar (GPR system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  7. Sensitivity of C-Band Polarimetric Radar-Based Drop Size Distribution Measurements to Maximum Diameter Assumptions

    Science.gov (United States)

    Carey, Lawrence D.; Petersen, Walter A.

    2011-01-01

    The estimation of rain drop size distribution (DSD) parameters from polarimetric radar observations is accomplished by first establishing a relationship between differential reflectivity (Z(sub dr)) and the central tendency of the rain DSD such as the median volume diameter (D0). Since Z(sub dr) does not provide a direct measurement of DSD central tendency, the relationship is typically derived empirically from rain drop and radar scattering models (e.g., D0 = F[Z (sub dr)] ). Past studies have explored the general sensitivity of these models to temperature, radar wavelength, the drop shape vs. size relation, and DSD variability. Much progress has been made in recent years in measuring the drop shape and DSD variability using surface-based disdrometers, such as the 2D Video disdrometer (2DVD), and documenting their impact on polarimetric radar techniques. In addition to measuring drop shape, another advantage of the 2DVD over earlier impact type disdrometers is its ability to resolve drop diameters in excess of 5 mm. Despite this improvement, the sampling limitations of a disdrometer, including the 2DVD, make it very difficult to adequately measure the maximum drop diameter (D(sub max)) present in a typical radar resolution volume. As a result, D(sub max) must still be assumed in the drop and radar models from which D0 = F[Z(sub dr)] is derived. Since scattering resonance at C-band wavelengths begins to occur in drop diameters larger than about 5 mm, modeled C-band radar parameters, particularly Z(sub dr), can be sensitive to D(sub max) assumptions. In past C-band radar studies, a variety of D(sub max) assumptions have been made, including the actual disdrometer estimate of D(sub max) during a typical sampling period (e.g., 1-3 minutes), D(sub max) = C (where C is constant at values from 5 to 8 mm), and D(sub max) = M*D0 (where the constant multiple, M, is fixed at values ranging from 2.5 to 3.5). The overall objective of this NASA Global Precipitation Measurement

  8. Millimeter-wave silicon-based ultra-wideband automotive radar transceivers

    Science.gov (United States)

    Jain, Vipul

    Since the invention of the integrated circuit, the semiconductor industry has revolutionized the world in ways no one had ever anticipated. With the advent of silicon technologies, consumer electronics became light-weight and affordable and paved the way for an Information-Communication-Entertainment age. While silicon almost completely replaced compound semiconductors from these markets, it has been unable to compete in areas with more stringent requirements due to technology limitations. One of these areas is automotive radar sensors, which will enable next-generation collision-warning systems in automobiles. A low-cost implementation is absolutely essential for widespread use of these systems, which leads us to the subject of this dissertation---silicon-based solutions for automotive radars. This dissertation presents architectures and design techniques for mm-wave automotive radar transceivers. Several fully-integrated transceivers and receivers operating at 22-29 GHz and 77-81 GHz are demonstrated in both CMOS and SiGe BiCMOS technologies. Excellent performance is achieved indicating the suitability of silicon technologies for automotive radar sensors. The first CMOS 22-29-GHz pulse-radar receiver front-end for ultra-wideband radars is presented. The chip includes a low noise amplifier, I/Q mixers, quadrature voltage-controlled oscillators, pulse formers and variable-gain amplifiers. Fabricated in 0.18-mum CMOS, the receiver achieves a conversion gain of 35-38.1 dB and a noise figure of 5.5-7.4 dB. Integration of multi-mode multi-band transceivers on a single chip will enable next-generation low-cost automotive radar sensors. Two highly-integrated silicon ICs are designed in a 0.18-mum BiCMOS technology. These designs are also the first reported demonstrations of mm-wave circuits with high-speed digital circuits on the same chip. The first mm-wave dual-band frequency synthesizer and transceiver, operating in the 24-GHz and 77-GHz bands, are demonstrated. All

  9. FPGA based hardware optimized implementation of signal processing system for LFM pulsed radar

    Science.gov (United States)

    Azim, Noor ul; Jun, Wang

    2016-11-01

    Signal processing is one of the main parts of any radar system. Different signal processing algorithms are used to extract information about different parameters like range, speed, direction etc, of a target in the field of radar communication. This paper presents LFM (Linear Frequency Modulation) pulsed radar signal processing algorithms which are used to improve target detection, range resolution and to estimate the speed of a target. Firstly, these algorithms are simulated in MATLAB to verify the concept and theory. After the conceptual verification in MATLAB, the simulation is converted into implementation on hardware using Xilinx FPGA. Chosen FPGA is Xilinx Virtex-6 (XC6LVX75T). For hardware implementation pipeline optimization is adopted and also other factors are considered for resources optimization in the process of implementation. Focusing algorithms in this work for improving target detection, range resolution and speed estimation are hardware optimized fast convolution processing based pulse compression and pulse Doppler processing.

  10. Sparse Representation Based Range-Doppler Processing for Integrated OFDM Radar-Communication Networks

    Directory of Open Access Journals (Sweden)

    Bo Kong

    2017-01-01

    Full Text Available In an integrated radar-communication network, multiuser access techniques with minimal performance degradation and without range-Doppler ambiguities are required, especially in a dense user environment. In this paper, a multiuser access scheme with random subcarrier allocation mechanism is proposed for orthogonal frequency division multiplexing (OFDM based integrated radar-communication networks. The expression of modulation Symbol-Domain method combined with sparse representation (SR for range-Doppler estimation is introduced and a parallel reconstruction algorithm is employed. The radar target detection performance is improved with less spectrum occupation. Additionally, a Doppler frequency detector is exploited to decrease the computational complexity. Numerical simulations show that the proposed method outperforms the traditional modulation Symbol-Domain method under ideal and realistic nonideal scenarios.

  11. Ground penetrating radar data used in discovery of the early Christian church of Notre Dame de Baudes near Labastide-du-Temple, France

    Directory of Open Access Journals (Sweden)

    Ted L Gragson

    2016-06-01

    Full Text Available Data on ground-penetrating radar transect files are provided that support the research presented in "Discovery and Appraisal of the Early Christian Church of Notre Dame de Baudes near Labastide-du-Temple, France" [1]. Data consist of 102 transect files obtained with a GSSI SIR-3000 controller and a 400 MHz center frequency antenna in two grid blocks covering ca. 2700 m2. The data are distributed raw without post-processing in SEG-Y rev. 1 format (little endian.

  12. Ground penetrating radar data used in discovery of the early Christian church of Notre Dame de Baudes near Labastide-du-Temple, France.

    Science.gov (United States)

    Gragson, Ted L; Thompson, Victor D; Leigh, David S; Hautefeuille, Florent

    2016-06-01

    Data on ground-penetrating radar transect files are provided that support the research presented in "Discovery and Appraisal of the Early Christian Church of Notre Dame de Baudes near Labastide-du-Temple, France" [1]. Data consist of 102 transect files obtained with a GSSI SIR-3000 controller and a 400 MHz center frequency antenna in two grid blocks covering ca. 2700 m(2). The data are distributed raw without post-processing in SEG-Y rev. 1 format (little endian).

  13. SURFACE GEOPHYSICAL EXPLORATION OF TX-TY TANK FARMS AT THE HANFORD SITE: RESULTS OF BACKGROUND CHARACTERIZATION WITH GROUND PENETRATING RADAR

    International Nuclear Information System (INIS)

    MYERS DA; CUBBAGE R; BRAUCHLA R; O'BRIEN G

    2008-01-01

    Ground penetrating radar surveys of the TX and TY tank farms were performed to identify existing infrastructure in the near surface environment. These surveys were designed to provide background information supporting Surface-to-Surface and Well-to-Well resistivity surveys of Waste Management Area TX-TY. The objective of the preliminary investigation was to collect background characterization information with GPR to understand the spatial distribution of metallic objects that could potentially interfere with the results from high resolution resistivity(trademark) surveys. The results of the background characterization confirm the existence of documented infrastructure, as well as highlight locations of possible additional undocumented subsurface metallic objects

  14. Nuclear reactor power as applied to a space-based radar mission

    Science.gov (United States)

    Jaffe, L.; Fujita, T.; Beatty, R.; Bhandari, P.; Chow, E.; Deininger, W.; Ewell, R.; Grossman, M.; Kia, T.; Nesmith, B.

    1988-01-01

    The SP-100 Project was established to develop and demonstrate feasibility of a space reactor power system (SRPS) at power levels of 10's of kilowatts to a megawatt. To help determine systems requirements for the SRPS, a mission and spacecraft were examined which utilize this power system for a space-based radar to observe moving objects. Aspects of the mission and spacecraft bearing on the power system were the primary objectives of this study; performance of the radar itself was not within the scope. The study was carried out by the Systems Design Audit Team of the SP-100 Project.

  15. Radar Based Flow and Water Level Forecasting in Sewer Systems:a danisk case study

    OpenAIRE

    Thorndahl, Søren; Rasmussen, Michael R.; Grum, M.; Neve, S. L.

    2009-01-01

    This paper describes the first radar based forecast of flow and/or water level in sewer systems in Denmark. The rainfall is successfully forecasted with a lead time of 1-2 hours, and flow/levels are forecasted an additional ½-1½ hours using models describing the behaviour of the sewer system. Both radar data and flow/water level model are continuously updated using online rain gauges and online in-sewer measurements, in order to make the best possible predictions. The project show very promis...

  16. Deposits related to supercritical flows in glacifluvial deltas and subaqueous ice-contact fans: Integrating facies analysis and ground-penetrating radar

    Science.gov (United States)

    Lang, Joerg; Sievers, Julian; Loewer, Markus; Igel, Jan; Winsemann, Jutta

    2017-04-01

    Bedforms related to supercritical flows have recently received much interest and the understanding of flow morphodynamics and depositional processes has been greatly advanced. However, outcrop studies of these bedforms are commonly hampered by their long wavelengths. Therefore, we combined outcrop-based facies analysis with extensive ground-penetrating radar (GPR) measurements. Different GPR antennas (200, 400 and 1500 MHz) were utilised to measure both long profiles and densely spaced grids in order to map the large-scale facies architecture and image the three-dimensional geometry of the deposits. The studied delta and subaqueous ice-contact fan successions were deposited within ice-dammed lakes, which formed along the margins of the Middle Pleistocene Scandinavian ice sheets across Northern Germany. These glacilacustrine depositional systems are characterised by high aggradation rates due to the rapid expansion and deceleration of high-energy sediment-laden flows, favouring the preservation of bedforms related to supercritical flows. In flow direction, delta foresets commonly display lenticular scours, which are 2 to 6 m wide and 0.15 to 0.5 m deep. Characteristically, scours are filled by upslope dipping backsets, consisting of pebbly sand. In a few cases, massive and deformed strata were observed, passing upflow into backsets. Across flow, scours are 2 to 3 m wide and typically display a concentric infill. The scour fills are commonly associated with subhorizontally or sinusoidal stratified pebbly sand. These facies types are interpreted as deposits of cyclic steps and antidunes, respectively, representing deposition from supercritical density flows, which formed during high meltwater discharge events or regressive slope failures (Winsemann et al., in review). The GPR-sections show that the scour fills form trains along the delta foresets, which can be traced for up to 15 m. The studied subaqueous ice-contact fan succession relates to the zone of flow

  17. Nuclear reactor power as applied to a space-based radar mission

    Science.gov (United States)

    Jaffe, L.; Beatty, R.; Bhandari, P.; Chow, E.; Deininger, W.; Ewell, R.; Fujita, T.; Grossman, M.; Bloomfield, H.; Heller, J.

    1988-01-01

    A space-based radar mission and spacecraft are examined to determine system requirements for a 300 kWe space nuclear reactor power system. The spacecraft configuration and its orbit, launch vehicle, and propulsion are described. Mission profiles are addressed, and storage in assembly orbit is considered. Dynamics and attitude control and the problems of nuclear and thermal radiation are examined.

  18. Radar Emission Sources Identification Based on Hierarchical Agglomerative Clustering for Large Data Sets

    Directory of Open Access Journals (Sweden)

    Janusz Dudczyk

    2016-01-01

    Full Text Available More advanced recognition methods, which may recognize particular copies of radars of the same type, are called identification. The identification process of radar devices is a more specialized task which requires methods based on the analysis of distinctive features. These features are distinguished from the signals coming from the identified devices. Such a process is called Specific Emitter Identification (SEI. The identification of radar emission sources with the use of classic techniques based on the statistical analysis of basic measurable parameters of a signal such as Radio Frequency, Amplitude, Pulse Width, or Pulse Repetition Interval is not sufficient for SEI problems. This paper presents the method of hierarchical data clustering which is used in the process of radar identification. The Hierarchical Agglomerative Clustering Algorithm (HACA based on Generalized Agglomerative Scheme (GAS implemented and used in the research method is parameterized; therefore, it is possible to compare the results. The results of clustering are presented in dendrograms in this paper. The received results of grouping and identification based on HACA are compared with other SEI methods in order to assess the degree of their usefulness and effectiveness for systems of ESM/ELINT class.

  19. Identification of Mine-Shaped Objects based on an Efficient Phase Stepped-Frequency Radar Approach

    DEFF Research Database (Denmark)

    Sørensen, Helge Bjarup Dissing; Jakobsen, Kaj Bjarne; Nymann, Ole

    1997-01-01

    a radar probe is moved automatically to measure in each grid point a set of reflection coefficients from which phase and amplitude information are extracted. Based on a simple processing of the phase information, quarternary image and template cross-correlation a successful detection of metal- and non...

  20. Initial Results from Radiometer and Polarized Radar-Based Icing Algorithms Compared to In-Situ Data

    Science.gov (United States)

    Serke, David; Reehorst, Andrew L.; King, Michael

    2015-01-01

    In early 2015, a field campaign was conducted at the NASA Glenn Research Center in Cleveland, Ohio, USA. The purpose of the campaign is to test several prototype algorithms meant to detect the location and severity of in-flight icing (or icing aloft, as opposed to ground icing) within the terminal airspace. Terminal airspace for this project is currently defined as within 25 kilometers horizontal distance of the terminal, which in this instance is Hopkins International Airport in Cleveland. Two new and improved algorithms that utilize ground-based remote sensing instrumentation have been developed and were operated during the field campaign. The first is the 'NASA Icing Remote Sensing System', or NIRSS. The second algorithm is the 'Radar Icing Algorithm', or RadIA. In addition to these algorithms, which were derived from ground-based remote sensors, in-situ icing measurements of the profiles of super-cooled liquid water (SLW) collected with vibrating wire sondes attached to weather balloons produced a comprehensive database for comparison. Key fields from the SLW-sondes include air temperature, humidity and liquid water content, cataloged by time and 3-D location. This work gives an overview of the NIRSS and RadIA products and results are compared to in-situ SLW-sonde data from one icing case study. The location and quantity of super-cooled liquid as measured by the in-situ probes provide a measure of the utility of these prototype hazard-sensing algorithms.

  1. Development of wide band digital receiver for atmospheric radars using COTS board based SDR

    Science.gov (United States)

    Yasodha, Polisetti; Jayaraman, Achuthan; Thriveni, A.

    2016-07-01

    Digital receiver extracts the received echo signal information, and is a potential subsystem for atmospheric radar, also referred to as wind profiling radar (WPR), which provides the vertical profiles of 3-dimensional wind vector in the atmosphere. This paper presents the development of digital receiver using COTS board based Software Defined Radio technique, which can be used for atmospheric radars. The developmental work is being carried out at National Atmospheric Research Laboratory (NARL), Gadanki. The digital receiver consists of a commercially available software defined radio (SDR) board called as universal software radio peripheral B210 (USRP B210) and a personal computer. USRP B210 operates over a wider frequency range from 70 MHz to 6 GHz and hence can be used for variety of radars like Doppler weather radars operating in S/C bands, in addition to wind profiling radars operating in VHF, UHF and L bands. Due to the flexibility and re-configurability of SDR, where the component functionalities are implemented in software, it is easy to modify the software to receive the echoes and process them as per the requirement suitable for the type of the radar intended. Hence, USRP B210 board along with the computer forms a versatile digital receiver from 70 MHz to 6 GHz. It has an inbuilt direct conversion transceiver with two transmit and two receive channels, which can be operated in fully coherent 2x2 MIMO fashion and thus it can be used as a two channel receiver. Multiple USRP B210 boards can be synchronized using the pulse per second (PPS) input provided on the board, to configure multi-channel digital receiver system. RF gain of the transceiver can be varied from 0 to 70 dB. The board can be controlled from the computer via USB 3.0 interface through USRP hardware driver (UHD), which is an open source cross platform driver. The USRP B210 board is connected to the personal computer through USB 3.0. Reference (10 MHz) clock signal from the radar master oscillator

  2. GLACIER MONITORING SYSTEM IN COLOMBIA - complementing glaciological measurements with laser-scanning and ground-penetrating radar surveys

    Science.gov (United States)

    Ceballos, Jorge; Micheletti, Natan; Rabatel, Antoine; Mölg, Nico; Zemp, Michael

    2015-04-01

    Colombia (South America) has six small glaciers (total glacierized area of 45 Km2); their geographical location, close to zero latitude, makes them very sensitive to climate changes. An extensive monitoring program is being performed since 2006 on two glaciers, with international cooperation supports. This presentation summarizes the results of glacier changes in Colombia and includes the latest results obtained within the CATCOS Project - Phase 1 (Capacity Building and Twinning for Climate Observing Systems) signed between Colombia and Switzerland, and within the Joint Mixte Laboratory GREAT-ICE (IRD - France), with the application of LiDAR technology and GPR-based ice thickness measurements at Conejeras Glacier. Conejeras Glacier (Lat. N. 4° 48' 56"; Long. W. 75° 22' 22"; Alt. Max. 4915m.; Alt. Min. 4730m. Area 0.2 Km2) is located on the north-western side of Santa Isabel Volcano. This glacier belongs to global glacier monitoring network of the World Glacier Monitoring Service (WGMS-ID: 2721). The surface mass balance is calculated monthly using the direct glaciological method. Between April 2006 and May 2014, Conejeras Glacier showed a cumulative loss of -21 m w.e. The CATCOS Project allowed to improve the glacier monitoring system in Colombia with two main actions: (1) a terrestrial laser scanner survey (RIEGL VZ-6000 terrestrial laser scanner, property of Universities of Lausanne and Fribourg); and (2) ice thickness measurements (Blue System Integration Ltd. Ice Penetrating Radar of property of IRD). The terrestrial laser-scanning survey allowed to realize an accurate digital terrain model of the glacier surface with 13 million points and a decimetric resolution. Ice thickness measurements showed an average glacier thickness of 22 meters and a maximum of 52 meters.

  3. Estimating the Above-Ground Biomass in Miombo Savanna Woodlands (Mozambique, East Africa Using L-Band Synthetic Aperture Radar Data

    Directory of Open Access Journals (Sweden)

    Maria J. Vasconcelos

    2013-03-01

    Full Text Available The quantification of forest above-ground biomass (AGB is important for such broader applications as decision making, forest management, carbon (C stock change assessment and scientific applications, such as C cycle modeling. However, there is a great uncertainty related to the estimation of forest AGB, especially in the tropics. The main goal of this study was to test a combination of field data and Advanced Land Observing Satellite (ALOS Phased Array L-band Synthetic Aperture Radar (PALSAR backscatter intensity data to reduce the uncertainty in the estimation of forest AGB in the Miombo savanna woodlands of Mozambique (East Africa. A machine learning algorithm, based on bagging stochastic gradient boosting (BagSGB, was used to model forest AGB as a function of ALOS PALSAR Fine Beam Dual (FBD backscatter intensity metrics. The application of this method resulted in a coefficient of correlation (R between observed and predicted (10-fold cross-validation forest AGB values of 0.95 and a root mean square error of 5.03 Mg·ha−1. However, as a consequence of using bootstrap samples in combination with a cross validation procedure, some bias may have been introduced, and the reported cross validation statistics could be overoptimistic. Therefore and as a consequence of the BagSGB model, a measure of prediction variability (coefficient of variation on a pixel-by-pixel basis was also produced, with values ranging from 10 to 119% (mean = 25% across the study area. It provides additional and complementary information regarding the spatial distribution of the error resulting from the application of the fitted model to new observations.

  4. Analysis of warm season thunderstorms using an object-oriented tracking method based on radar and total lightning data

    Directory of Open Access Journals (Sweden)

    T. Rigo

    2010-09-01

    Full Text Available Monitoring thunderstorms activity is an essential part of operational weather surveillance given their potential hazards, including lightning, hail, heavy rainfall, strong winds or even tornadoes. This study has two main objectives: firstly, the description of a methodology, based on radar and total lightning data to characterise thunderstorms in real-time; secondly, the application of this methodology to 66 thunderstorms that affected Catalonia (NE Spain in the summer of 2006. An object-oriented tracking procedure is employed, where different observation data types generate four different types of objects (radar 1-km CAPPI reflectivity composites, radar reflectivity volumetric data, cloud-to-ground lightning data and intra-cloud lightning data. In the framework proposed, these objects are the building blocks of a higher level object, the thunderstorm.

    The methodology is demonstrated with a dataset of thunderstorms whose main characteristics, along the complete life cycle of the convective structures (development, maturity and dissipation, are described statistically. The development and dissipation stages present similar durations in most cases examined. On the contrary, the duration of the maturity phase is much more variable and related to the thunderstorm intensity, defined here in terms of lightning flash rate. Most of the activity of IC and CG flashes is registered in the maturity stage. In the development stage little CG flashes are observed (2% to 5%, while for the dissipation phase is possible to observe a few more CG flashes (10% to 15%. Additionally, a selection of thunderstorms is used to examine general life cycle patterns, obtained from the analysis of normalized (with respect to thunderstorm total duration and maximum value of variables considered thunderstorm parameters. Among other findings, the study indicates that the normalized duration of the three stages of thunderstorm life cycle is similar in most thunderstorms

  5. Analysis of warm season thunderstorms using an object-oriented tracking method based on radar and total lightning data

    Science.gov (United States)

    Rigo, T.; Pineda, N.; Bech, J.

    2010-09-01

    Monitoring thunderstorms activity is an essential part of operational weather surveillance given their potential hazards, including lightning, hail, heavy rainfall, strong winds or even tornadoes. This study has two main objectives: firstly, the description of a methodology, based on radar and total lightning data to characterise thunderstorms in real-time; secondly, the application of this methodology to 66 thunderstorms that affected Catalonia (NE Spain) in the summer of 2006. An object-oriented tracking procedure is employed, where different observation data types generate four different types of objects (radar 1-km CAPPI reflectivity composites, radar reflectivity volumetric data, cloud-to-ground lightning data and intra-cloud lightning data). In the framework proposed, these objects are the building blocks of a higher level object, the thunderstorm. The methodology is demonstrated with a dataset of thunderstorms whose main characteristics, along the complete life cycle of the convective structures (development, maturity and dissipation), are described statistically. The development and dissipation stages present similar durations in most cases examined. On the contrary, the duration of the maturity phase is much more variable and related to the thunderstorm intensity, defined here in terms of lightning flash rate. Most of the activity of IC and CG flashes is registered in the maturity stage. In the development stage little CG flashes are observed (2% to 5%), while for the dissipation phase is possible to observe a few more CG flashes (10% to 15%). Additionally, a selection of thunderstorms is used to examine general life cycle patterns, obtained from the analysis of normalized (with respect to thunderstorm total duration and maximum value of variables considered) thunderstorm parameters. Among other findings, the study indicates that the normalized duration of the three stages of thunderstorm life cycle is similar in most thunderstorms, with the longest

  6. Fourier-Based Transmit Beampattern Design Using MIMO Radar

    KAUST Repository

    Lipor, John

    2014-05-01

    In multiple-input multiple-output (MIMO) radar settings, it is often desirable to transmit power only to a given location or set of locations defined by a beampattern. Transmit waveform design is a topic that has received much attention recently, involving synthesis of both the signal covariance matrix,, as well as the actual waveforms. Current methods involve a two-step process of designing via iterative solutions and then using to generate waveforms that fulfill practical constraints such as having a constant-envelope or drawing from a finite alphabet. In this paper, a closed-form method to design for a uniform linear array is proposed that utilizes the discrete Fourier transform (DFT) coefficients and Toeplitz matrices. The resulting covariance matrix fulfills the practical constraints such as positive semidefiniteness and the uniformelemental power constraint and provides performance similar to that of iterative methods, which require a much greater computation time. Next, a transmit architecture is presented that exploits the orthogonality of frequencies at discrete DFT values to transmit a sum of orthogonal signals from each antenna. The resulting waveforms provide a lower mean-square error than current methods at a much lower computational cost, and a simulated detection scenario demonstrates the performance advantages achieved.

  7. Improved OAM-Based Radar Targets Detection Using Uniform Concentric Circular Arrays

    Directory of Open Access Journals (Sweden)

    Mingtuan Lin

    2016-01-01

    Full Text Available Without any relative moves or beam scanning, the novel Orbital-Angular-Momentum- (OAM- based radar targets detection technique using uniform concentric circular arrays (UCCAs shows the azimuthal estimation ability, which provides new perspective for radar system design. However, the main estimation method, that is, Fast Fourier Transform (FFT, under this scheme suffers from low resolution. As a solution, this paper rebuilds the OAM-based radar targets detection model and introduces the multiple signal classification (MUSIC algorithm to improve the resolution for detecting targets within the main lobes. The spatial smoothing technique is proposed to tackle the coherent problem brought by the proposed model. Analytical study and simulation demonstrate the superresolution estimation capacity the MUSIC algorithm can achieve for detecting targets within the main lobes. The performance of the MUSIC algorithm to detect targets not illuminated by the main lobes is further evaluated. Despite the fact that MUSIC algorithm loses the resolution advantage under this case, its estimation is more robust than that of the FFT method. Overall, the proposed MUSIC algorithm for the OAM-based radar system demonstrates the superresolution ability for detecting targets within the main lobes and good robustness for targets out of the main lobes.

  8. A Technique for Real-Time Ionospheric Ranging Error Correction Based On Radar Dual-Frequency Detection

    Science.gov (United States)

    Lyu, Jiang-Tao; Zhou, Chen

    2017-12-01

    Ionospheric refraction is one of the principal error sources for limiting the accuracy of radar systems for space target detection. High-accuracy measurement of the ionospheric electron density along the propagation path of radar wave is the most important procedure for the ionospheric refraction correction. Traditionally, the ionospheric model and the ionospheric detection instruments, like ionosonde or GPS receivers, are employed for obtaining the electron density. However, both methods are not capable of satisfying the requirements of correction accuracy for the advanced space target radar system. In this study, we propose a novel technique for ionospheric refraction correction based on radar dual-frequency detection. Radar target range measurements at two adjacent frequencies are utilized for calculating the electron density integral exactly along the propagation path of the radar wave, which can generate accurate ionospheric range correction. The implementation of radar dual-frequency detection is validated by a P band radar located in midlatitude China. The experimental results present that the accuracy of this novel technique is more accurate than the traditional ionospheric model correction. The technique proposed in this study is very promising for the high-accuracy radar detection and tracking of objects in geospace.

  9. Comparison of EISCAT and ionosonde electron densities: application to a ground-based ionospheric segment of a space weather programme

    Directory of Open Access Journals (Sweden)

    J. Lilensten

    2005-01-01

    Full Text Available Space weather applications require real-time data and wide area observations from both ground- and space-based instrumentation. From space, the global navigation satellite system - GPS - is an important tool. From the ground the incoherent scatter (IS radar technique permits a direct measurement up to the topside region, while ionosondes give good measurements of the lower part of the ionosphere. An important issue is the intercalibration of these various instruments. In this paper, we address the intercomparison of the EISCAT IS radar and two ionosondes located at Tromsø (Norway, at times when GPS measurements were also available. We show that even EISCAT data calibrated using ionosonde data can lead to different values of total electron content (TEC when compared to that obtained from GPS.

  10. Advancing Understanding of the Role of Belowground Processes in Terrestrial Carbon Sinks trhrough Ground-Penetrating Radar. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Day, Frank P. [Old Dominion Univ., Norfolk, VA (United States)

    2015-02-06

    Coarse roots play a significant role in belowground carbon cycling and will likely play an increasingly crucial role in belowground carbon sequestration as atmospheric CO2 levels continue to rise, yet they are one of the most difficult ecosystem parameters to quantify. Despite promising results with ground-penetrating radar (GPR) as a nondestructive method of quantifying biomass of coarse roots, this application of GPR is in its infancy and neither the complete potential nor limitations of the technology have been fully evaluated. The primary goals and questions of this study fell into four groups: (1) GPR methods: Can GPR detect change in root biomass over time, differentiate live roots from dead roots, differentiate between coarse roots, fine roots bundled together, and a fine root mat, remain effective with varied soil moisture, and detect shadowed roots (roots hidden below larger roots); (2) CO2 enrichment study at Kennedy Space Center in Brevard County, Florida: Are there post-fire legacy effects of CO2 fertilization on plant carbon pools following the end of CO2application ? (3) Disney Wilderness Study: What is the overall coarse root biomass and potential for belowground carbon storage in a restored longleaf pine flatwoods system? Can GPR effectively quantify coarse roots in soils that are wetter than the previous sites and that have a high percentage of saw palmetto rhizomes present? (4) Can GPR accurately represent root architecture in a three-dimensional model? When the user is familiar with the equipment and software in a setting that minimizes unsuitable conditions, GPR is a relatively precise, non-destructive, useful tool for estimating coarse root biomass. However, there are a number of cautions and guidelines that should be followed to minimize inaccuracies or situations that are untenable for GPR use. GPR appears to be precise as it routinely predicts highly similar values for a given area across multiple

  11. Short-Range Vital Signs Sensing Based on EEMD and CWT Using IR-UWB Radar

    Directory of Open Access Journals (Sweden)

    Xikun Hu

    2016-11-01

    Full Text Available The radar sensor described realizes healthcare monitoring capable of detecting subject chest-wall movement caused by cardiopulmonary activities and wirelessly estimating the respiration and heartbeat rates of the subject without attaching any devices to the body. Conventional single-tone Doppler radar can only capture Doppler signatures because of a lack of bandwidth information with noncontact sensors. In contrast, we take full advantage of impulse radio ultra-wideband (IR-UWB radar to achieve low power consumption and convenient portability, with a flexible detection range and desirable accuracy. A noise reduction method based on improved ensemble empirical mode decomposition (EEMD and a vital sign separation method based on the continuous-wavelet transform (CWT are proposed jointly to improve the signal-to-noise ratio (SNR in order to acquire accurate respiration and heartbeat rates. Experimental results illustrate that respiration and heartbeat signals can be extracted accurately under different conditions. This noncontact healthcare sensor system proves the commercial feasibility and considerable accessibility of using compact IR-UWB radar for emerging biomedical applications.

  12. Radar-based quantitative precipitation estimation for the identification of debris flow occurrence over earthquake-affected regions in Sichuan, China

    Science.gov (United States)

    Shi, Zhao; Wei, Fangqiang; Chandrasekar, Venkatachalam

    2018-03-01

    Both Ms 8.0 Wenchuan earthquake on 12 May 2008 and Ms 7.0 Lushan earthquake on 20 April 2013 occurred in the province of Sichuan, China. In the earthquake-affected mountainous area, a large amount of loose material caused a high occurrence of debris flow during the rainy season. In order to evaluate the rainfall intensity-duration (I-D) threshold of the debris flow in the earthquake-affected area, and to fill up the observational gaps caused by the relatively scarce and low-altitude deployment of rain gauges in this area, raw data from two S-band China New Generation Doppler Weather Radar (CINRAD) were captured for six rainfall events that triggered 519 debris flows between 2012 and 2014. Due to the challenges of radar quantitative precipitation estimation (QPE) over mountainous areas, a series of improvement measures are considered: a hybrid scan mode, a vertical reflectivity profile (VPR) correction, a mosaic of reflectivity, a merged rainfall-reflectivity (R - Z) relationship for convective and stratiform rainfall, and rainfall bias adjustment with Kalman filter (KF). For validating rainfall accumulation over complex terrains, the study areas are divided into two kinds of regions by the height threshold of 1.5 km from the ground. Three kinds of radar rainfall estimates are compared with rain gauge measurements. It is observed that the normalized mean bias (NMB) is decreased by 39 % and the fitted linear ratio between radar and rain gauge observation reaches at 0.98. Furthermore, the radar-based I-D threshold derived by the frequentist method is I = 10.1D-0.52 and is underestimated by uncorrected raw radar data. In order to verify the impacts on observations due to spatial variation, I-D thresholds are identified from the nearest rain gauge observations and radar observations at the rain gauge locations. It is found that both kinds of observations have similar I-D thresholds and likewise underestimate I-D thresholds due to undershooting at the core of convective

  13. Lunar regolith stratigraphy analysis based on the simulation of lunar penetrating radar signals

    Science.gov (United States)

    Lai, Jialong; Xu, Yi; Zhang, Xiaoping; Tang, Zesheng

    2017-11-01

    The thickness of lunar regolith is an important index of evaluating the quantity of lunar resources such as 3He and relative geologic ages. Lunar penetrating radar (LPR) experiment of Chang'E-3 mission provided an opportunity of in situ lunar subsurface structure measurement in the northern mare imbrium area. However, prior work on analyzing LPR data obtained quite different conclusions of lunar regolith structure mainly because of the missing of clear interface reflectors in radar image. In this paper, we utilized finite-difference time-domain (FDTD) method and three models of regolith structures with different rock density, number of layers, shapes of interfaces, and etc. to simulate the LPR signals for the interpretation of radar image. The simulation results demonstrate that the scattering signals caused by numerous buried rocks in the regolith can mask the horizontal reflectors, and the die-out of radar echo does not indicate the bottom of lunar regolith layer and data processing such as migration method could recover some of the subsurface information but also result in fake signals. Based on analysis of simulation results, we conclude that LPR results uncover the subsurface layered structure containing the rework zone with multiple ejecta blankets of small crater, the ejecta blanket of Chang'E-3 crater, and the transition zone and estimate the thickness of the detected layer is about 3.25 m.

  14. Lava flows in mare imbrium: An evaluation of anomalously low earth-based radar reflectivity

    Science.gov (United States)

    Schaber, G.G.; Thompson, T.W.; Zisk, S.H.

    1975-01-01

    The lunar maria reflect two to five times less Earth-based radar power than the highlands, the spectrally blue maria surfaces returning the lowest power levels. This effect of weakening signal return has been attributed to increased signal absorption related to the electrical and magnetic characteristics of the mineral ilmenite (FeTiO3). The surface of Mare Imbrium contains some of the most distinct red-blue colorimetric boundaries and depolarized 70 cm wavelength reflectivity variations on the near side of the Moon. The weakest levels of both 3.8 cm and 70 cm reflectivity within Imbrium are confined to regional mare surfaces of the blue spectral type that can be recognized as stratigraphically unique flow surfaces. Frequency distributions of the 70 cm polarized and depolarized radar return power for five mare surfaces within the basin indicate that signal absorption, and probably the ilmenite content, increases generally from the beginning of the Imbrian Period to the end of the Eratosthenian Period with slight reversal between the end of the Imbrian and beginning of the Eratosthenian. TiO2 calibrated radar reflectivity curves can be utilized for lunar maria geochemical mapping in the same manner as the TiO2 calibrated spectral reflectivity curves of Charette et al. (1974). The long wavelength radar data may be a sensitive indicator of mare chemical variations as it is unaffected by the normal surface rock clutter that includes ray materials from large impact craters. ?? 1975 D. Reidel Publishing Company.

  15. Feature-Based Correlation and Topological Similarity for Interbeat Interval Estimation Using Ultrawideband Radar.

    Science.gov (United States)

    Sakamoto, Takuya; Imasaka, Ryohei; Taki, Hirofumi; Sato, Toru; Yoshioka, Mototaka; Inoue, Kenichi; Fukuda, Takeshi; Sakai, Hiroyuki

    2016-04-01

    The objectives of this paper are to propose a method that can accurately estimate the human heart rate (HR) using an ultrawideband (UWB) radar system, and to determine the performance of the proposed method through measurements. The proposed method uses the feature points of a radar signal to estimate the HR efficiently and accurately. Fourier- and periodicity-based methods are inappropriate for estimation of instantaneous HRs in real time because heartbeat waveforms are highly variable, even within the beat-to-beat interval. We define six radar waveform features that enable correlation processing to be performed quickly and accurately. In addition, we propose a feature topology signal that is generated from a feature sequence without using amplitude information. This feature topology signal is used to find unreliable feature points, and thus, to suppress inaccurate HR estimates. Measurements were taken using UWB radar, while simultaneously performing electrocardiography measurements in an experiment that was conducted on nine participants. The proposed method achieved an average root-mean-square error in the interbeat interval of 7.17 ms for the nine participants. The results demonstrate the effectiveness and accuracy of the proposed method. The significance of this study for biomedical research is that the proposed method will be useful in the realization of a remote vital signs monitoring system that enables accurate estimation of HR variability, which has been used in various clinical settings for the treatment of conditions such as diabetes and arterial hypertension.

  16. ''Swords into ploughshares'': Breaking new ground with radar hardware and technique in physical research after World War II

    International Nuclear Information System (INIS)

    Forman, P.

    1995-01-01

    A survey is offered of applications to fundamental physical research, in the years immediately following World War II, of the instrumentalities developed for radar during that war. Attention is given to radar astronomy and radio astronomy, linear and cyclical accelerators, microwave spectroscopy, molecular beams, nuclear magnetic resonance, electron paramagnetic and ferromagnetic resonance, measurements of resistivity at high frequencies in metals and of second sound in helium II, and to the concepts of information and signal-to-noise ratio as basic to the design and analysis of experiments. In conjunction with this survey, consideration is given to the autonomy of physics as a knowledge-producing enterprise, framed as a question of continuity in research directions. As that question implies a baseline, the survey of postwar applications is preceded by a survey of those prewar directions of physical research requiring the highest available radio frequencies. Some 500 references are given

  17. Analysis of Human's Motions Based on Local Mean Decomposition in Through-wall Radar Detection

    Science.gov (United States)

    Lu, Qi; Liu, Cai; Zeng, Zhaofa; Li, Jing; Zhang, Xuebing

    2016-04-01

    Observation of human motions through a wall is an important issue in security applications and search-and rescue. Radar has advantages in looking through walls where other sensors give low performance or cannot be used at all. Ultrawideband (UWB) radar has high spatial resolution as a result of employment of ultranarrow pulses. It has abilities to distinguish the closely positioned targets and provide time-lapse information of targets. Moreover, the UWB radar shows good performance in wall penetration when the inherently short pulses spread their energy over a broad frequency range. Human's motions show periodic features including respiration, swing arms and legs, fluctuations of the torso. Detection of human targets is based on the fact that there is always periodic motion due to breathing or other body movements like walking. The radar can gain the reflections from each human body parts and add the reflections at each time sample. The periodic movements will cause micro-Doppler modulation in the reflected radar signals. Time-frequency analysis methods are consider as the effective tools to analysis and extract micro-Doppler effects caused by the periodic movements in the reflected radar signal, such as short-time Fourier transform (STFT), wavelet transform (WT), and Hilbert-Huang transform (HHT).The local mean decomposition (LMD), initially developed by Smith (2005), is to decomposed amplitude and frequency modulated signals into a small set of product functions (PFs), each of which is the product of an envelope signal and a frequency modulated signal from which a time-vary instantaneous phase and instantaneous frequency can be derived. As bypassing the Hilbert transform, the LMD has no demodulation error coming from window effect and involves no negative frequency without physical sense. Also, the instantaneous attributes obtained by LMD are more stable and precise than those obtained by the empirical mode decomposition (EMD) because LMD uses smoothed local

  18. Past sea-level data from Lakse Bugt, Disko Island, West Greenland from ground-penetrating radar data

    Science.gov (United States)

    Souza, Priscila E.; Nielsen, Lars; Kroon, Aart; Clemmensen, Lars B.

    2016-04-01

    Beach-ridge deposits have been used as sea-level indicators in numerous studies from temperate coastal regions. However, their present surface morphology in artic regions may not accurately correspond to past sea-level, because subsequent surface erosion, solifluction processes and/or later sediment deposition may have altered the surface significantly. The internal structure of these beach ridges, however, is often well-preserved and thus constitutes an important key to reconstruction of past sea levels as seen elsewhere. In the present study, high-resolution reflection GPR data and high-precision topographic data were collected at Lakse Bugt (Disko Island, West Greenland) using a shielded 250 MHz antennae system and a RTK-Trimble R8 DGPS, respectively. Three transects were collected across a sequence of fossil, raised beach ridge deposits, and two transects were obtained across modern beach deposits at the shoreline of the mesotidal regime. Along all radar profiles we observed downlap reflection points, which we interpret to represent the boundary between sediments deposited on the beachface and sediments deposited in the upper shoreface regime. Both the upper shoreface and the beachface deposits exhibit reflection patterns dipping in the seaward direction. The beachface deposits show the strongest dip. At or just below the downlap points strong diffractions are often observed indicating the presence of a layer containing stones. These stones are large enough to generate significant signal scattering. At the present day beach a sharp transition defined by the presence of large stones is observed near the low tide water level: cobbles characterize the seaside, while the land side is characterized by sand and gravel. Therefore, it seems reasonable to conclude that downlap points observed in the GPR data serve as indicators of past low-tide levels (at the time of deposition). The downlap points show a consistent offset with respect to present surface topography

  19. Proposed satellite position determination systems and techniques for Geostationary Synthetic Aperture Radar

    OpenAIRE

    Martin Fuster, Roger; Fernández Usón, Marc; Casado Blanco, David; Broquetas Ibars, Antoni

    2016-01-01

    This paper proposes two different calibration techniques for Geostationary Synthetic Aperture Radar (GEOSAR) missions requiring a high precision positioning, based on Active Radar Calibrators and Ground Based Interferometry. The research is enclosed in the preparation studies of a future GEOSAR mission providing continuous monitoring at continental scale. Peer Reviewed

  20. Coupling Fine-Scale Root and Canopy Structure Using Ground-Based Remote Sensing

    Directory of Open Access Journals (Sweden)

    Brady S. Hardiman

    2017-02-01

    Full Text Available Ecosystem physical structure, defined by the quantity and spatial distribution of biomass, influences a range of ecosystem functions. Remote sensing tools permit the non-destructive characterization of canopy and root features, potentially providing opportunities to link above- and belowground structure at fine spatial resolution in functionally meaningful ways. To test this possibility, we employed ground-based portable canopy LiDAR (PCL and ground penetrating radar (GPR along co-located transects in forested sites spanning multiple stages of ecosystem development and, consequently, of structural complexity. We examined canopy and root structural data for coherence (i.e., correlation in the frequency of spatial variation at multiple spatial scales ≤10 m within each site using wavelet analysis. Forest sites varied substantially in vertical canopy and root structure, with leaf area index and root mass more becoming even vertically as forests aged. In all sites, above- and belowground structure, characterized as mean maximum canopy height and root mass, exhibited significant coherence at a scale of 3.5–4 m, and results suggest that the scale of coherence may increase with stand age. Our findings demonstrate that canopy and root structure are linked at characteristic spatial scales, which provides the basis to optimize scales of observation. Our study highlights the potential, and limitations, for fusing LiDAR and radar technologies to quantitatively couple above- and belowground ecosystem structure.

  1. To See the Unseen: A History of Planetary Radar Astronomy

    Science.gov (United States)

    Butrica, Andrew J.

    1996-01-01

    This book relates the history of planetary radar astronomy from its origins in radar to the present day and secondarily to bring to light that history as a case of 'Big Equipment but not Big Science'. Chapter One sketches the emergence of radar astronomy as an ongoing scientific activity at Jodrell Bank, where radar research revealed that meteors were part of the solar system. The chief Big Science driving early radar astronomy experiments was ionospheric research. Chapter Two links the Cold War and the Space Race to the first radar experiments attempted on planetary targets, while recounting the initial achievements of planetary radar, namely, the refinement of the astronomical unit and the rotational rate and direction of Venus. Chapter Three discusses early attempts to organize radar astronomy and the efforts at MIT's Lincoln Laboratory, in conjunction with Harvard radio astronomers, to acquire antenna time unfettered by military priorities. Here, the chief Big Science influencing the development of planetary radar astronomy was radio astronomy. Chapter Four spotlights the evolution of planetary radar astronomy at the Jet Propulsion Laboratory, a NASA facility, at Cornell University's Arecibo Observatory, and at Jodrell Bank. A congeries of funding from the military, the National Science Foundation, and finally NASA marked that evolution, which culminated in planetary radar astronomy finding a single Big Science patron, NASA. Chapter Five analyzes planetary radar astronomy as a science using the theoretical framework provided by philosopher of science Thomas Kuhn. Chapter Six explores the shift in planetary radar astronomy beginning in the 1970s that resulted from its financial and institutional relationship with NASA Big Science. Chapter Seven addresses the Magellan mission and its relation to the evolution of planetary radar astronomy from a ground-based to a space-based activity. Chapters Eight and Nine discuss the research carried out at ground-based

  2. Echo simulation of lunar penetrating radar: based on a model of inhomogeneous multilayer lunar regolith structure

    International Nuclear Information System (INIS)

    Dai Shun; Su Yan; Xiao Yuan; Feng Jian-Qing; Xing Shu-Guo; Ding Chun-Yu

    2014-01-01

    Lunar Penetrating Radar (LPR) based on the time domain Ultra-Wideband (UWB) technique onboard China's Chang'e-3 (CE-3) rover, has the goal of investigating the lunar subsurface structure and detecting the depth of lunar regolith. An inhomogeneous multi-layer microwave transfer inverse-model is established. The dielectric constant of the lunar regolith, the velocity of propagation, the reflection, refraction and transmission at interfaces, and the resolution are discussed. The model is further used to numerically simulate and analyze temporal variations in the echo obtained from the LPR attached on CE-3's rover, to reveal the location and structure of lunar regolith. The thickness of the lunar regolith is calculated by a comparison between the simulated radar B-scan images based on the model and the detected result taken from the CE-3 lunar mission. The potential scientific return from LPR echoes taken from the landing region is also discussed

  3. Detection-Discrimination Method for Multiple Repeater False Targets Based on Radar Polarization Echoes

    Directory of Open Access Journals (Sweden)

    Z. W. ZONG

    2014-04-01

    Full Text Available Multiple repeat false targets (RFTs, created by the digital radio frequency memory (DRFM system of jammer, are widely used in practical to effectively exhaust the limited tracking and discrimination resource of defence radar. In this paper, common characteristic of radar polarization echoes of multiple RFTs is used for target recognition. Based on the echoes from two receiving polarization channels, the instantaneous polarization radio (IPR is defined and its variance is derived by employing Taylor series expansion. A detection-discrimination method is designed based on probability grids. By using the data from microwave anechoic chamber, the detection threshold of the method is confirmed. Theoretical analysis and simulations indicate that the method is valid and feasible. Furthermore, the estimation performance of IPRs of RFTs due to the influence of signal noise ratio (SNR is also covered.

  4. Echo simulation of lunar penetrating radar: based on a model of inhomogeneous multilayer lunar regolith structure

    Science.gov (United States)

    Dai, Shun; Su, Yan; Xiao, Yuan; Feng, Jian-Qing; Xing, Shu-Guo; Ding, Chun-Yu

    2014-12-01

    Lunar Penetrating Radar (LPR) based on the time domain Ultra-Wideband (UWB) technique onboard China's Chang'e-3 (CE-3) rover, has the goal of investigating the lunar subsurface structure and detecting the depth of lunar regolith. An inhomogeneous multi-layer microwave transfer inverse-model is established. The dielectric constant of the lunar regolith, the velocity of propagation, the reflection, refraction and transmission at interfaces, and the resolution are discussed. The model is further used to numerically simulate and analyze temporal variations in the echo obtained from the LPR attached on CE-3's rover, to reveal the location and structure of lunar regolith. The thickness of the lunar regolith is calculated by a comparison between the simulated radar B-scan images based on the model and the detected result taken from the CE-3 lunar mission. The potential scientific return from LPR echoes taken from the landing region is also discussed.

  5. Ambiguity Function Analysis and Processing for Passive Radar Based on CDR Digital Audio Broadcasting

    Directory of Open Access Journals (Sweden)

    Zhang Qiang

    2015-01-01

    Full Text Available China Digital Radio (CDR broadcasting is a new standard of digital audio broadcasting of FM frequency (87–108 MHz based on our research and development efforts. It is compatible with the frequency spectrum in analog FM radio and satisfies the requirements for smooth transition from analog to digital signal in FM broadcasting in China. This paper focuses on the signal characteristics and processing methods of radio-based passive radar. The signal characteristics and ambiguity function of a passive radar illumination source are analyzed. The adverse effects on the target detection of the side peaks owing to cyclic prefix, the Doppler ambiguity strips because of signal synchronization, and the range of side peaks resulting from the signal discontinuous spectrum are then studied. Finally, methods for suppressing these side peaks are proposed and their effectiveness is verified by simulations.

  6. A Ground Penetrating Radar (GPR) Survey of KIilbourne Hole, Southern New Mexico: Implication for Paleohydrology and Near Surface Geophysical Exploration of Mars and the Moon

    Science.gov (United States)

    Rhodes, N.; Hurtado, J. M.

    2013-05-01

    Features such as the Home Plate plateau on Mars, a suspected remnant of a phreatomagmatic eruption, can reveal important information about paleohydrologic conditions. The types and sizes of pyroclastic rocks produced by a phreatomagmatic eruption are indicative of the behavior of the explosion and the characteristics of the groundwater reservoir. Analysis of the pyroclast size distribution can be used to determine magma volatile content. We conduct an analysis of pyroclast size distribution using Ground Penetrating Radar (GPR) to make a quantitative estimate of the presence of past groundwater at Kilbourne Hole, a well-known phreatomagmatic crater located in southern Dona Ana County, New Mexico. As basaltic magma intruded the groundwater reservoir in the mid-Pleistocene, the water vaporized and caused a phreatomagmatic explosion that excavated the 2-km wide and 200-m deep depression. The pyroclastic units produced during a phreatomagmatic explosion are proportional to the size and the duration of the explosion and the size of the groundwater reservoir such that the wetter the eruption, the stronger the explosion. In a violent volcanic eruption, magma changes from a liquid into solid fragments and the explosion releases kinetic energy (Ek) by ejecting liquid water, vapor water (with mass Mw) and solid fragments (with mass Mf) at an ejection velocity (Ve). In order to determine Mw, we must know Ve. The relationship between Ve and the distance from center of the eruption (R) is such that Ve exponentially decreases with time (t) and R. A numerical model relating pyroclast size and Ve for material ejected in Hawaiian and Plinian eruptions shows that clast size also exponentially decreases with decreasing Ve. Based on these relationships, we use GPR to map the ejected clast size distribution as a function of distance from the edge of Kilbourne Hole in an effort to determine Ve and Mw. GPR surveys were performed in January 2012 and January 2013 using a Noggins 250 MHz

  7. Integration of a satellite ground support system based on analysis of the satellite ground support domain

    Science.gov (United States)

    Pendley, R. D.; Scheidker, E. J.; Levitt, D. S.; Myers, C. R.; Werking, R. D.

    1994-11-01

    This analysis defines a complete set of ground support functions based on those practiced in real space flight operations during the on-orbit phase of a mission. These functions are mapped against ground support functions currently in use by NASA and DOD. Software components to provide these functions can be hosted on RISC-based work stations and integrated to provide a modular, integrated ground support system. Such modular systems can be configured to provide as much ground support functionality as desired. This approach to ground systems has been widely proposed and prototyped both by government institutions and commercial vendors. The combined set of ground support functions we describe can be used as a standard to evaluate candidate ground systems. This approach has also been used to develop a prototype of a modular, loosely-integrated ground support system, which is discussed briefly. A crucial benefit to a potential user is that all the components are flight-qualified, thus giving high confidence in their accuracy and reliability.

  8. A radar-based hydrological model for flash flood prediction in the dry regions of Israel

    Sci