WorldWideScience

Sample records for geos satellites

  1. Photometrical research geostationary satellite "SBIRS GEO-2"

    Science.gov (United States)

    Sukhov, P. P.; Epishev, V. P; Sukhov, K. P; Kudak, V. I.

    The multicolor photometrical observations GSS "Sbirs Geo-2" were carried in B,V,R filters out during the autumn equinox 2014 and spring 2015 y. Periodic appearance of many light curves and dips of mirror reflections suggests that the GSS was not in orbit in a static position, predetermined three-axis orientation and in dynamic motion. On the basis of computer modeling suggests the following dynamics GSS "Sbirs Geo-2" in orbit. Helically scanning the visible Earth's surface infrared satellite sensors come with period P1 = 15.66 sec. and the rocking of the GSS about the direction of the motion vector of the satellite in orbit with P2 = 62.64 sec., most likely with the purpose to survey the greatest possible portion of the earth's surface.

  2. GEO Satellites as Space Weather Sensors

    Science.gov (United States)

    2016-04-26

    Solar Energy , Jan. 2016. Lohmeyer, W. and K. Cahoy, "Space Weather Radiation Effects on Geostationary Satellite Solid-State Power Amplifiers...with space weather observations and models. We analyzed two component types: solar cells and high power amplifiers. For amplifiers, we identified the...analysis  focused  on  two  component  types:   solar  cells  and  high   power  amplifiers.  We  have  calculated

  3. East–West GEO Satellite Station-Keeping with Degraded Thruster Response

    OpenAIRE

    Stoian Borissov; Yunhe Wu; Daniele Mortari

    2015-01-01

    The higher harmonic terms of Earth’s gravitational potential slowly modify the nominal longitude of geostationary Earth orbit (GEO) satellites, while the third-body presence (Moon and Sun) mainly affects their latitude. For this reason, GEO satellites periodically need to perform station-keeping maneuvers, namely, east–west and north–south maneuvers to compensate for longitudinal and latitudinal variations, respectively. During the operational lifetime of GEO satellites, the thrusters’ respon...

  4. COVERAGE PERFORMANCES ANALYSIS ON COMBINED-GEO-IGSO SATELLITE CONSTELLATION1

    Institute of Scientific and Technical Information of China (English)

    Jiang Yong; Yang Sen; Zhang Gengxin; Li Guangxia

    2011-01-01

    The Combined-GEO-IGSO constellation is the combination of Geostationary Earth Orbit (GEO) satellite and Inclining GeoSynchronons Orbit (IGSO) satellite.The Combined-GEO-IGSO constellation can integrate the advantages of GEO and IGSO to achieve regional coverage.In order to discuss the performances of the Combined-GEO-IGSO constellation,the performances of coverage,elevation,diversity,and transmission are simulated in China and surrounding regions by Satellite Tool Kit (STK).The simulation results show that:the combined constellation can reach higher multi-satellite coverage and higher communication elevation in China and surrounding areas; the Doppler shift,delay,and propagation loss of this constellation have little impact on the system.As regional coverage constellation,the Combined-GEO-IGSO is feasible.

  5. Photometric Studies of Rapidly Spinning Decommissioned GEO Satellites

    Science.gov (United States)

    Ryan, W.; Ryan, E.

    A satellites general characteristics can be substantially influenced by changes in the space environment. Rapidly spinning decommissioned satellites provide an excellent opportunity to study the rotation-dependent physical processes that affect a resident space objects (RSO) spin kinematics over time. Specifically, inactive satellites at or near geosynchronous Earth-orbit (GEO) provide easy targets for which high quality data can be collected and analyzed such that small differences can be detected under single-year or less time frames. Previous workers have shown that the rotational periods of defunct GEOs have been changing over time [1]. Further, the Yarkovsky-OKeefe-Radzievskii-Paddak (YORP) effect, a phenomenon which has been well-studied in the context of the changing the spin states of asteroids, has recently been suggested to be the cause of secular alterations in the rotational period of inactive satellites [2]. Researchers at the Magdalena Ridge Observatory 2.4-meter telescope (operated by the New Mexico Institute of Mining and Technology) have been investigating the spins states of retired GEOs and other high altitude space debris since 2007 [3]. In this current work, the 2.4-meter telescope was used to track and observe the objects typically over a one- to two-hour period, repeated several times over the course of weeks. When feasible, this is then repeated on a yearly basis. Data is taken with a 1 second cadence, nominally in groups of three 600 second image sets. With the current equipment, the cadence of the image sequences is very precise while the start time is accurate only to the nearest second. Therefore, periods are determined individually using each image sequence. Repeatability of the period determination for each of these sequences is typically on the order of 0.01 second or better for objects where a single period is identified. Spin rate periods determined from the GEO light curves collected thus far have been found to range from ~3 sec to

  6. Performance Analysis for Regional Satellite Positioning System Based upon GEO/HEO Hybrid Constellation

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Scheme of positioning constellation would greatly influence the positioning performance. In this paper, a GEO/HEO hybrid constellation with 3 HEO satellites deployed in 3 orbits and 3 GEO satellites for regional positioning is presented. Firstly, elements for 3 GEO and 3 HEO are optimized from regional visibility for the selected region of interest. Secondly, positioning performance is provided through GDOP(geometric dilution of precision) and PDOP(positional dilution of precision). Simulation results show that similar accuracy with GPS can be gained by this constellation.

  7. Surrogate assisted multidisciplinary design optimization for an all-electric GEO satellite

    Science.gov (United States)

    Shi, Renhe; Liu, Li; Long, Teng; Liu, Jian; Yuan, Bin

    2017-09-01

    State-of-the-art all-electric geostationary earth orbit (GEO) satellites use electric thrusters to execute all propulsive duties, which significantly differ from the traditional all-chemical ones in orbit-raising, station-keeping, radiation damage protection, and power budget, etc. Design optimization task of an all-electric GEO satellite is therefore a complex multidisciplinary design optimization (MDO) problem involving unique design considerations. However, solving the all-electric GEO satellite MDO problem faces big challenges in disciplinary modeling techniques and efficient optimization strategy. To address these challenges, we presents a surrogate assisted MDO framework consisting of several modules, i.e., MDO problem definition, multidisciplinary modeling, multidisciplinary analysis (MDA), and surrogate assisted optimizer. Based on the proposed framework, the all-electric GEO satellite MDO problem is formulated to minimize the total mass of the satellite system under a number of practical constraints. Then considerable efforts are spent on multidisciplinary modeling involving geosynchronous transfer, GEO station-keeping, power, thermal control, attitude control, and structure disciplines. Since orbit dynamics models and finite element structural model are computationally expensive, an adaptive response surface surrogate based optimizer is incorporated in the proposed framework to solve the satellite MDO problem with moderate computational cost, where a response surface surrogate is gradually refined to represent the computationally expensive MDA process. After optimization, the total mass of the studied GEO satellite is decreased by 185.3 kg (i.e., 7.3% of the total mass). Finally, the optimal design is further discussed to demonstrate the effectiveness of our proposed framework to cope with the all-electric GEO satellite system design optimization problems. This proposed surrogate assisted MDO framework can also provide valuable references for other all

  8. Functions of retired GEO communication satellites in improving the PDOP value of CAPS

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper briefly introduces the maneuverable feature of the slightly inclined geosynchronous orbit (SIGSO) satellites under a new control model degraded from the geosynchronous orbit (GEO) communication satellites which will retire as most of the fuel in these satellites has been consumed. Basing on the transmitting Chinese Area Positioning System (CAPS), the authors, by analyses, indicate that such satellites can make an improvement to CAPS constellation configuration, especially to the PDOP value from simulation. The results show that the use of SIGSO satellites can (1) actualize three-dimensional (3D) navigation and positioning compared with the situation, which, only using GEO satellites, cannot be carried out, and improve navigation and positioning accuracy to some extent; (2) reuse the communication services of these satellites for more years, and GEO communication satellites will be retired at a later time and delay their time to become space debris and reduce their pollution of the space environment, so that valuable space resources are maximally used. As for the use of these satellites in the transmitting positioning system, the authors present some views and suggestions in this work.

  9. Functions of retired GEO communication satellites in improving the PDOP value of CAPS

    Institute of Scientific and Technical Information of China (English)

    HAN YanBen; MA LiHua; QIAO QiYuan; YIN ZhiQiang; SHI HuLi; AI GuoXiang

    2009-01-01

    This paper briefly Introduces the maneuverable feature of the slightly Inclined geosynchronous orbit (SlGSO) satellites under e new control model degraded from the geosynchronous orbit (GEO) communication satellites which will retire as most of the fuel in these satellites has been consumed.Basing on the transmitting Chinese Area Positioning System (CAPS),the authors,by analyses,indicate that such satellites can make an improvement to CAPS constellation configuration,especially to the PDOP value from simulation.The results show that the use of SIGSO satellites can (1) actualize three-dimensional (3D) navigation and positioning compared with the situation,which,only using GEO satellites,cannot be carried out,and improve navigation and positioning accuracy to some extent; (2) reuse the communication services of these satellites for more years,and GEO communication satellites will be retired at a later time and delay their time to become space debris and reduce their pollution of the apace environment,so that valuable space resources are maximally used.As for the use of these satellites in the transmitting positioning system,the authors present some views and suggestions in this work.

  10. Soil Moisture Retrieval Using Reflected Signals of BeiDou GEO Satellites

    Directory of Open Access Journals (Sweden)

    ZOU Wenbo

    2016-02-01

    Full Text Available This paper proposes a method of continuous long-term soil moisture measurement using signals from BeiDou GEO satellites. It also presents the soil moisture inversion model as well as the relevant signal processing steps. Moreover, a land-based experiment is carried out to verify its validity. This method adopts the dual-antenna Global Navigation Satellite System Reflection (GNSS-R mode to receive and process direct signal from BeiDou GEO satellites and reflected signal from soil. Based on signal synchronization, the reflectivity of soil can be calculated according to the extracted signal power values. And then, the soil moisture can be obtained in light of the inversion model. By taking singals from BeiDou GEO satellites, not only the positioning calculation step of general GNSS-R data processing can be ignored, but also a continuous long-term observation of soil moisture for fixed area can be realized. Experiment results based on the method above show a good continuity in both time and magnitude. They are also highly consistent with reference values and the root mean square error equals to 0.049. Compared with BeiDou IGSO and GPS MEO satellites, BeiDou GEO satellites can present a better performance in soil moisture retrieval.

  11. East–West GEO Satellite Station-Keeping with Degraded Thruster Response

    Directory of Open Access Journals (Sweden)

    Stoian Borissov

    2015-09-01

    Full Text Available The higher harmonic terms of Earth’s gravitational potential slowly modify the nominal longitude of geostationary Earth orbit (GEO satellites, while the third-body presence (Moon and Sun mainly affects their latitude. For this reason, GEO satellites periodically need to perform station-keeping maneuvers, namely, east–west and north–south maneuvers to compensate for longitudinal and latitudinal variations, respectively. During the operational lifetime of GEO satellites, the thrusters’ response when commanded to perform these maneuvers slowly departs from the original nominal impulsive behavior. This paper addresses the practical problem of how to perform reliable east–west station-keeping maneuvers when thruster response is degraded. The need for contingency intervention from ground-based satellite operators is reduced by breaking apart the scheduled automatic station-keeping maneuvers into smaller maneuvers. Orbital alignment and attitude are tracked on-board during and in between sub-maneuvers, and any off nominal variations are corrected for with subsequent maneuvers. These corrections are particularly important near the end of the lifetime of GEO satellites, where thruster response is farthest from nominal performance.

  12. Studies of oceanic tectonics based on GEOS-3 satellite altimetry

    Science.gov (United States)

    Poehls, K. A.; Kaula, W. M.; Schubert, G.; Sandwell, D.

    1979-01-01

    Using statistical analysis, geoidal admittance (the relationship between the ocean geoid and seafloor topography) obtained from GEOS-3 altimetry was compared to various model admittances. Analysis of several altimetry tracks in the Pacific Ocean demonstrated a low coherence between altimetry and seafloor topography except where the track crosses active or recent tectonic features. However, global statistical studies using the much larger data base of all available gravimetry showed a positive correlation of oceanic gravity with topography. The oceanic lithosphere was modeled by simultaneously inverting surface wave dispersion, topography, and gravity data. Efforts to incorporate geoid data into the inversion showed that the base of the subchannel can be better resolved with geoid rather than gravity data. Thermomechanical models of seafloor spreading taking into account differing plate velocities, heat source distributions, and rock rheologies were discussed.

  13. Analysis of Faint Glints from Stabilized GEO Satellites

    Science.gov (United States)

    2013-09-01

    Galaxy 14, which use Orbital’s Star -2 TM design, featuring a roughly cubical bus (measuring 1.75 m  1.7 m  1.8 m) and two solar panels (each measuring...satellites can be used for characterization. Figure 1. Artists renderings of the Galaxy 12, 14 and 15 geosynchronous satellites [11]. 3 GLINTS...glints in addition to those Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is

  14. Terminal-to-Terminal Calling for GEO Broadband Mobile Satellite Communication

    Institute of Scientific and Technical Information of China (English)

    Jinsheng Yang

    2015-01-01

    Satellite and terrestrial components of IMT⁃Advanced need to be integrated so that the traditional strengths of each compo⁃nent can be fully exploited. LTE/LTE⁃A is now a recognized foundation of terrestrial 4G networks, and mobile satellite net⁃works should be based on it. Long transmission delay is one of the main disadvantages of satellite communication, espe⁃cially in a GEO system, and terminal⁃to⁃terminal (TtT) design reduces this delay. In this paper, we propose a protocol archi⁃tecture based on LTE/LTE⁃A for GEO mobile satellite commu⁃nication. We propose a detailed call procedure and four TtT modes for this architecture. We describe the division of tasks between the satellite gateway (SAT⁃GW) and satellite as well as TtT processing in the physical layer of the satellite in or⁃der to reduce delay and ensure compatibility with a terrestrial LTE/LTE⁃A system.

  15. Adaptive Optics for Satellite and Debris Imaging in LEO and GEO

    Science.gov (United States)

    Copeland, M.; Bennet, F.; Zovaro, A.; Riguat, F.; Piatrou, P.; Korkiakoski, V.; Smith, C.

    2016-09-01

    The Research School of Astronomy and Astrophysics (RSAA) at the Australian National University has developed and Adaptive Optics (AO) system for satellite and debris imaging in low Earth orbit (LEO) and geostationary orbit (GEO). In LEO the size, shape and orientation of objects will be measured with resolution of 50 cm for objects at 800 km range at an 800 nm imaging wavelength. In GEO satellite position will be measured using precision astrometry of nearby stars. We use an AO system with a deformable mirror (DM) of 277 actuators and Shack-Hartmann wavefront sensor operating at 2 kHz. Imaging is performed at a rate of >30 Hz to reduce image blur due to tip-tilt and rotation. We use two imaging modes; a high resolution mode to obtain Nyquist sampled images and a acquisition mode with 75 arcsecond field of view to aid in finding targets.

  16. The geo-control system for station keeping and colocation of geostationary satellites

    Science.gov (United States)

    Montenbruck, O.; Eckstein, M. C.; Gonner, J.

    1993-01-01

    GeoControl is a compact but powerful and accurate software system for station keeping of single and colocated satellites, which has been developed at the German Space Operations Center. It includes four core modules for orbit determination (including maneuver estimation), maneuver planning, monitoring of proximities between colocated satellites, and interference and event prediction. A simple database containing state vector and maneuver information at selected epochs is maintained as a central interface between the modules. A menu driven shell utilizing form screens for data input serves as the central user interface. The software is written in Ada and FORTRAN and may be used on VAX workstations or mainframes under the VMS operating system.

  17. Computing procedure of spatial geo-referencing of satellite image; Un procedimiento simple de geo-referenciacion de imagenes de satelite

    Energy Technology Data Exchange (ETDEWEB)

    Santos, J.; Vazquez, M.; Fernandes, F.; Prado, T.; Castro, R.

    2004-07-01

    In this paper a computing procedure of spatial geo-referencing is described that, by means of the terrestrial spatial geometry, permits to obtain the Latitude and Longitude that corresponds to a given pixel of a satellite image, the pixel being defined by a pair Line- Pixel. The procedure also permits to compute the other way round. This procedure is more clear and simple than those proposed by Eumetsat and Goes and can be applied to any satellite image. (Author)

  18. Geo-correction Algorithm Based on Equivalent RD Model for ScanSAR of HJ-1-C Satellite

    Directory of Open Access Journals (Sweden)

    Liu Jia-yin

    2014-06-01

    Full Text Available HJ-1-C satellite is the first Synthetic Aperture Radar (SAR satellite for civilian use in China, and it has a strip and scan mode. According to the characteristics of the ScanSAR of the HJ-1-C satellite, a geo-correction algorithm based on an equivalent RD model has been outlined in this paper on the basis of an ECS image processing algorithm and a traditional Range-Doppler location method. An azimuth mosaic was presented by a time series relationship, then the different burst was stitched by range, and the equivalent parameters were fitted to locations on the RD model. Finally, the ScanSAR image was geo-corrected. The HJ-1-C satellite data results showed that the location accuracy of ScanSAR for the HJ-1-C satellite was less than 100 m, and the geo-correction algorithm was realized in 10 s in fewer than 24 parallel cores.

  19. Precise orbit determination of a maneuvered GEO satellite using CAPS ranging data

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Wheel-off-loadings and orbital maneuvers of the GEO satellite result in additional accelerations to the satellite itself. Complex and difficult to model, these time varying accelerations are an important error source of precise orbit determination (POD). In most POD practices, only non-maneuver orbital arcs are treated. However, for some applications such as satellite navigation RDSS services, uninterrupted orbital ephemeris is demanded, requiring the development of POD strategies to be processed both during and after an orbital maneuver. We in this paper study the POD for a maneuvered GEO satellite, using high precision and high sampling rate ranging data obtained with Chinese Area Positioning System (CAPS). The strategy of long arc POD including maneuver arcs is studied by using telemetry data to model the maneuver thrust process. Combining the thrust and other orbital perturbations, a long arc of 6 days’ CAPS ranging data is analyzed. If the telemetry data are not available or contain significant errors, attempts are made to estimate thrusting parameters using CAPS ranging data in the POD as an alternative to properly account for the maneuver. Two strategies achieve reasonably good data fitting level in the tested arc with the maximal position difference being about 20 m.

  20. Precise orbit determination of a maneuvered GEO satellite using CAPS ransing data

    Institute of Scientific and Technical Information of China (English)

    HUANG Yong; HU XiaoGong; HUANG Cheng; YANG QiangWen; JIAO WenHai

    2009-01-01

    Wheel-off-loadings and orbital maneuvers of the GEO satellite result in additional accelerations to the satellite itself.Complex and difficult to model,these time varying accelerations are an important error source of precise orbit determination (POD).In most POD practices,only non-maneuver orbital arcs are treated.However,for some applications such as satellite navigation RDSS services,uninterrupted orbital ephemeris is demanded,requiring the development of POD strategies to be processed both during and after an orbital maneuver.We in this paper study the POD for a maneuvered GEO satellite,using high precision and high sampling rate ranging data obtained with Chinese Area Positioning System (CAPS).The strategy of long arc POD including maneuver arcs is studied by using telemetry data to model the maneuver thrust process.Combining the thrust and other orbital perturbations,a long arc of 6 days' CAPS ranging data is analyzed.If the telemetry data are not available or contain significant errors,attempts are made to estimate thrusting parameters using CAPS ranging data in the POD as an alternative to properly account for the maneuver.Two strategies achieve reasonably good data fitting level in the tested arc with the maximal position difference being about 20m.

  1. Precise orbit determination of a maneuvered GEO satellite using CAPS ranging data

    Science.gov (United States)

    Huang, Yong; Hu, Xiaogong; Huang, Cheng; Yang, Qiangwen; Jiao, Wenhai

    2009-03-01

    Wheel-off-loadings and orbital maneuvers of the GEO satellite result in additional accelerations to the satellite itself. Complex and difficult to model, these time varying accelerations are an important error source of precise orbit determination (POD). In most POD practices, only non-maneuver orbital arcs are treated. However, for some applications such as satellite navigation RDSS services, uninterrupted orbital ephemeris is demanded, requiring the development of POD strategies to be processed both during and after an orbital maneuver. We in this paper study the POD for a maneuvered GEO satellite, using high precision and high sampling rate ranging data obtained with Chinese Area Positioning System (CAPS). The strategy of long arc POD including maneuver arcs is studied by using telemetry data to model the maneuver thrust process. Combining the thrust and other orbital perturbations, a long arc of 6 days’ CAPS ranging data is analyzed. If the telemetry data are not available or contain significant errors, attempts are made to estimate thrusting parameters using CAPS ranging data in the POD as an alternative to properly account for the maneuver. Two strategies achieve reasonably good data fitting level in the tested arc with the maximal position difference being about 20 m.

  2. Feasibility study on UV/visible imaging spectrograph (Geo-OPUS) for GOAL satellite proposal

    Science.gov (United States)

    Suzuki, M.; Kita, K.; Toshimi, T.; Okumura, S.; Shiomi, K.; Imamura, T.; Nakamura, M.

    Geo-OPUS geostationary ozone and air pollution monitoring UV visible spectrometer is a core instrument of GOAL geostationary observation of atmospheric chemistry and lightning satellite proposal Geo-OPUS is an imaging spectrograph to scan earth disk 20km x 20 km nadir pixel 512 north-south pixels IFOV and whole disk FOV within 1 hour observation cycle which observes 270-450 nm with 0 3 nm spectral sampling Onboard spectral calibration 0 01 nm accuracy is carried out using Hg lamp and solar lines Radio Diffuser plates are used for radiometric calibration Primary observation targets are total column of NO2 SO2 O3 also stratospheric profile HCHO and aerosols It also measures stratospheric species OClO BrO etc High SNR and spectral calibration stability are required to derive species such as tropospheric O3 column in 10-20 accuracy required by IGOS-P IGACO

  3. GEOS-2 refraction program summary document. [ionospheric and tropospheric propagation errors in satellite tracking instruments

    Science.gov (United States)

    Mallinckrodt, A. J.

    1977-01-01

    Data from an extensive array of collocated instrumentation at the Wallops Island test facility were intercompared in order to (1) determine the practical achievable accuracy limitations of various tropospheric and ionospheric correction techniques; (2) examine the theoretical bases and derivation of improved refraction correction techniques; and (3) estimate internal systematic and random error levels of the various tracking stations. The GEOS 2 satellite was used as the target vehicle. Data were obtained regarding the ionospheric and tropospheric propagation errors, the theoretical and data analysis of which was documented in some 30 separate reports over the last 6 years. An overview of project results is presented.

  4. Development of a Reduction Algorithm of GEO Satellite Optical Observation Data for Optical Wide Field Patrol (OWL)

    Science.gov (United States)

    Park, Sun-youp; Choi, Jin; Jo, Jung Hyun; Son, Ju Young; Park, Yung-Sik; Yim, Hong-Suh; Moon, Hong-Kyu; Bae, Young-Ho; Choi, Young-Jun; Park, Jang-Hyun

    2015-09-01

    An algorithm to automatically extract coordinate and time information from optical observation data of geostationary orbit satellites (GEO satellites) or geosynchronous orbit satellites (GOS satellites) is developed. The optical wide-field patrol system is capable of automatic observation using a pre-arranged schedule. Therefore, if this type of automatic analysis algorithm is available, daily unmanned monitoring of GEO satellites can be possible. For data acquisition for development, the COMS1 satellite was observed with 1-s exposure time and 1-m interval. The images were grouped and processed in terms of ¡°action¡±, and each action was composed of six or nine successive images. First, a reference image with the best quality in one action was selected. Next, the rest of the images in the action were geometrically transformed to fit in the horizontal coordinate system (expressed in azimuthal angle and elevation) of the reference image. Then, these images were median-combined to retain only the possible non-moving GEO candidates. By reverting the coordinate transformation of the positions of these GEO satellite candidates, the final coordinates could be calculated.

  5. Exploiting Deep Matching and SAR Data for the Geo-Localization Accuracy Improvement of Optical Satellite Images

    Directory of Open Access Journals (Sweden)

    Nina Merkle

    2017-06-01

    Full Text Available Improving the geo-localization of optical satellite images is an important pre-processing step for many remote sensing tasks like monitoring by image time series or scene analysis after sudden events. These tasks require geo-referenced and precisely co-registered multi-sensor data. Images captured by the high resolution synthetic aperture radar (SAR satellite TerraSAR-X exhibit an absolute geo-location accuracy within a few decimeters. These images represent therefore a reliable source to improve the geo-location accuracy of optical images, which is in the order of tens of meters. In this paper, a deep learning-based approach for the geo-localization accuracy improvement of optical satellite images through SAR reference data is investigated. Image registration between SAR and optical images requires few, but accurate and reliable matching points. These are derived from a Siamese neural network. The network is trained using TerraSAR-X and PRISM image pairs covering greater urban areas spread over Europe, in order to learn the two-dimensional spatial shifts between optical and SAR image patches. Results confirm that accurate and reliable matching points can be generated with higher matching accuracy and precision with respect to state-of-the-art approaches.

  6. Classification of Clouds and Deep Convection from GEOS-5 Using Satellite Observations

    Science.gov (United States)

    Putman, William; Suarez, Max

    2010-01-01

    With the increased resolution of global atmospheric models and the push toward global cloud resolving models, the resemblance of model output to satellite observations has become strikingly similar. As we progress with our adaptation of the Goddard Earth Observing System Model, Version 5 (GEOS-5) as a high resolution cloud system resolving model, evaluation of cloud properties and deep convection require in-depth analysis beyond a visual comparison. Outgoing long-wave radiation (OLR) provides a sufficient comparison with infrared (IR) satellite imagery to isolate areas of deep convection. We have adopted a binning technique to generate a series of histograms for OLR which classify the presence and fraction of clear sky versus deep convection in the tropics that can be compared with a similar analyses of IR imagery from composite Geostationary Operational Environmental Satellite (GOES) observations. We will present initial results that have been used to evaluate the amount of deep convective parameterization required within the model as we move toward cloud system resolving resolutions of 10- to 1-km globally.

  7. Aerus-GEO: newly available satellite-derived aerosol optical depth product over Europe and Africa

    Science.gov (United States)

    Carrer, D.; Roujean, J. L.; Ceamanos, X.; Six, B.; Suman, S.

    2015-12-01

    The major difficulty in detecting the aerosol signal from visible and near-infrared remote sensing observations is to reach the proper separation of the components related to the atmosphere and the surface. A method is proposed to circumvent this issue by exploiting the directional and temporal dimensions of the satellite signal through the use of a semi-empirical kernel-driven model for the surface/atmosphere coupled system. This algorithm was implemented by the ICARE Data Center (http://www.icare.univ-lille1.fr), which operationally disseminates a daily AOD product at 670 nm over the MSG disk since 2014. The proposed method referred to as AERUS-GEO (Aerosol and surface albEdo Retrieval Using a directional Splitting method - application to GEO data) is applied to three spectral bands (0.6 mm, 0.8 mm, and 1.6 mm) of MSG (Meteosat Second Generation) observations, which scan Europe, Africa, and the Eastern part of South America every 15 minutes. The daily AOD estimates at 0.63μm has been extensively validated. In contrast, the Angstrom coefficient is still going through validation and we will show the differences between the MSG derived Angstrom exponent with that of CAMS (Copernicus Atmosphere Monitoring Service) near-real time aerosol product. The impact of aerosol type on the aerosol radiative forcing will be presented as a part of future development plan.

  8. The Application of GeoRSC Based on Domestic Satellite in Field Remote Sensing Anomaly Verification

    Science.gov (United States)

    Gao, Ting; Yang, Min; Han, Haihui; Li, Jianqiang; Yi, Huan

    2016-11-01

    The Geo REC is the digital remote sensing survey system which based on domestic satellites, and by means of it, the thesis carriedy out a remote sensing anomaly verification field application test in Nachitai area of Qinghai. Field test checks the system installation, the stability of the system operation, the efficiency of reading and show the romoate image or vector data, the security of the data management system and the accuracy of BeiDou navigation; through the test data, the author indicated that the hardware and software system could satisfy the remote sensing anomaly verification work in field, which could also could make it convenient forconvenient the workflow of remote sense survey and, improve the work efficiency,. Aat the same time, in the course of the experiment, we also found some shortcomings of the system, and give some suggestions for improvement combineding with the practical work for the system.

  9. Establishing a Robotic, LEO-to-GEO Satellite Servicing Infrastructure as an Economic Foundation for Exploration

    Science.gov (United States)

    Horsham, Gary A. P.; Schmidt, George R.; Gilland, James H.

    2010-01-01

    The strategy for accomplishing civilian exploration goals and objectives is in the process of a fundamental shift towards a potential new approach called Flexible Path. This paper suggests that a government-industry or public-private partnership in the commercial development of low Earth orbit to geostationary orbit (LEO-to-GEO (LTG)) space, following or in parallel with the commercialization of Earth-to-LEO and International Space Station (ISS) operations, could serve as a necessary, logical step that can be incorporated into the flexible path approach. A LTG satellite-servicing infrastructure and architecture concept is discussed within this new strategic context. The concept consists of a space harbor that serves as a transport facility for a fleet of specialized, fully- or semi-autonomous robotic servicing spacecraft. The baseline, conceptual system architecture is composed of a space harbor equipped with specialized servicer spacecraft; a satellite command, communication, and control system; a parts station; a fuel station or depot; and a fuel/parts replenishment transport. The commercial servicer fleet would consist of several types of spacecraft, each designed with specialized robotic manipulation subsystems to provide services such as refueling, upgrade, repair, inspection, relocation, and removal. The space harbor is conceptualized as an ISS-type, octagonal truss structure equipped with radiation tolerant subsystems. This space harbor would be primarily capable of serving as an operational platform for various commercially owned and operated servicer spacecraft positioned and docked symmetrically on four of the eight sides. Several aspects of this concept are discussed, such as: system-level feasibility in terms of ISS-truss-type infrastructure and subsystems emplacement and maintenance between LEO and GEO; infrastructure components assembly in LEO, derived from ISS assembly experience, and transfer to various higher orbital locations; the evolving Earth

  10. Geo-correction Algorithm Based on Equivalent RD Model for ScanSAR of HJ-1-C Satellite

    OpenAIRE

    Liu Jia-yin; Wen Shuang-yan; Zhang Hong-yi; Hong Wen

    2014-01-01

    HJ-1-C satellite is the first Synthetic Aperture Radar (SAR) satellite for civilian use in China, and it has a strip and scan mode. According to the characteristics of the ScanSAR of the HJ-1-C satellite, a geo-correction algorithm based on an equivalent RD model has been outlined in this paper on the basis of an ECS image processing algorithm and a traditional Range-Doppler location method. An azimuth mosaic was presented by a time series relationship, then the different burst was stitched b...

  11. Assessment of the Contribution of BeiDou GEO, IGSO, and MEO Satellites to PPP in Asia—Pacific Region

    Directory of Open Access Journals (Sweden)

    Qile Zhao

    2015-12-01

    Full Text Available In contrast to the US Global Positioning System (GPS, the Russian Global Navigation Satellite System (GLONASS and the European Galileo, the developing Chinese BeiDou satellite navigation system (BDS consists of not only Medium Earth Orbit (MEO, but also Geostationary Orbit (GEO as well as Inclined Geosynchronous Orbit (IGSO satellites. In this study, the Precise Point Positioning (PPP and PPP with Integer Ambiguity Resolution (IAR are obtained. The contributions of these three different types of BDS satellites to PPP in Asia-Pacific region are assessed using data from selected 20 sites over more than four weeks. By using various PPP cases with different satellite combinations, in general, the largest contribution of BDS IGSO among the three kinds of BDS satellites to the reduction of convergence time and the improvement of positioning accuracy, particularly in the east direction, is identified. These PPP cases include static BDS only solutions and static/kinematic ambiguity-float and -fixed PPP with the combination of GPS and BDS. The statistical results demonstrate that the inclusion of BDS GEO and MEO satellites can improve the observation condition and result in better PPP performance as well. When combined with GPS, the contribution of BDS to the reduction of convergence time is, however, not as significant as that of GLONASS. As far as the positioning accuracy is concerned, GLONASS improves the accuracy in vertical component more than BDS does, whereas similar improvement in horizontal component can be achieved by inclusion of BDS IGSO and MEO as GLONASS.

  12. A study of possible sea state information in the sample and hold gate statistics for the GEOS-3 satellite altimeter

    Science.gov (United States)

    Wells, W. T.; Borman, K. L.; Mitchell, R. D.; Dempsey, D. J.

    1979-01-01

    The statistical variations in the sample gate outputs of the GEOS-3 satellite altimeter were studied for possible sea state information. After examination of a large number of statistical characteristics of the altimeter waveforms, it was found that the best sea predictor for H-1/3 in the range of 0 to 3 meters was the 75th percentile of sample and hold gate number 11.

  13. Design Concepts for a Small Space-Based GEO Relay Satellite for Missions Between Low Earth and near Earth Orbits

    Science.gov (United States)

    Bhasin, Kul B.; Warner, Joseph D.; Oleson, Steven; Schier, James

    2014-01-01

    The main purpose of the Small Space-Based Geosynchronous Earth orbiting (GEO) satellite is to provide a space link to the user mission spacecraft for relaying data through ground networks to user Mission Control Centers. The Small Space Based Satellite (SSBS) will provide services comparable to those of a NASA Tracking Data Relay Satellite (TDRS) for the same type of links. The SSBS services will keep the user burden the same or lower than for TDRS and will support the same or higher data rates than those currently supported by TDRS. At present, TDRSS provides links and coverage below GEO; however, SSBS links and coverage capability to above GEO missions are being considered for the future, especially for Human Space Flight Missions (HSF). There is also a rising need for the capability to support high data rate links (exceeding 1 Gbps) for imaging applications. The communication payload on the SSBS will provide S/Ka-band single access links to the mission and a Ku-band link to the ground, with an optical communication payload as an option. To design the communication payload, various link budgets were analyzed and many possible operational scenarios examined. To reduce user burden, using a larger-sized antenna than is currently in use by TDRS was considered. Because of the SSBS design size, it was found that a SpaceX Falcon 9 rocket could deliver three SSBSs to GEO. This will greatly reduce the launch costs per satellite. Using electric propulsion was also evaluated versus using chemical propulsion; the power system size and time to orbit for various power systems were also considered. This paper will describe how the SSBS will meet future service requirements, concept of operations, and the design to meet NASA users' needs for below and above GEO missions. These users' needs not only address the observational mission requirements but also possible HSF missions to the year 2030. We will provide the trade-off analysis of the communication payload design in terms of

  14. 美军SBIRS GEO-1预警卫星探测预警能力分析%Analysis on infrared detecting and early warning capabilities of America's SBIRS GEO-1 satellite

    Institute of Scientific and Technical Information of China (English)

    李小将; 金山; 廖海玲; 王建华

    2013-01-01

    For effectively responding to the threats of ballistic missiles and protecting the US's national and allies' interests, the US army continually develops and consummates the space-based infrared early warning system. The paper introduces the status and development of US's space-based infrared system,explores the coverage characteristic of the first space-based infrared geosynchronous orbit satellite,builds the GEO-1 satellite's infrared detecting model and early warning model, analyzes the detecting and early warning efficiencies of SBIRS GEO-1 satellite.%为有效应对弹道导弹威胁,维护本土与盟国利益,美军不断发展完善其天基红外预警系统.介绍了美军天基红外系统的发展现状,分析了首颗天基红外系统静止轨道(SBIRS GEO-1)卫星的覆盖范围,建立了SBIRS GEO-1卫星的红外探测模型和弹道预警模型,对其在轨探测预警能力进行了初步仿真分析.

  15. Reference crop evapotranspiration derived from geo-stationary satellite imagery: a case study for the Fogera flood plain, NW-Ethiopia and the Jordan Valley, Jordan

    NARCIS (Netherlands)

    Bruin, de H.A.R.; Trigo, I.F.; Jitan, M.A.; Enku, N.T.; Tol, van der C.; Gieske, A.S.M.

    2010-01-01

    First results are shown of a project aiming to estimate daily values of reference crop evapotranspiration ET0 from geo-stationary satellite imagery. In particular, for Woreta, a site in the Ethiopian highland at an elevation of about 1800 m, we tested a radiation-temperature based approximate formul

  16. Reference crop evapotranspiration derived from geo-stationary satellite imagery: a case study for the Fogera flood plain, NW-Ethiopia and the Jordan Valley, Jordan

    NARCIS (Netherlands)

    Bruin, de H.A.R.; Trigo, I.F.; Jitan, M.A.; Enku, N.T.; Tol, van der C.; Gieske, A.S.M.

    2010-01-01

    First results are shown of a project aiming to estimate daily values of reference crop evapotranspiration ET0 from geo-stationary satellite imagery. In particular, for Woreta, a site in the Ethiopian highland at an elevation of about 1800 m, we tested a radiation-temperature based approximate

  17. USGS Small-scale Dataset - 100-Meter Resolution Satellite View of Hawaii 201304 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of Hawaii map layer is a 100-meter resolution simulated natural-color image of Hawaii. Vegetation is generally green, with forests in darker green...

  18. USGS Small-scale Dataset - 100-Meter Resolution Satellite View of Alaska 201304 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of Alaska map layer is a 100-meter resolution simulated natural-color image of Alaska. Vegetation is generally green, with forests in darker green...

  19. USGS Small-scale Dataset - Satellite View of Hawaii, with Shaded Relief 200603 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of Hawaii, with Shaded Relief map layer is a 200- meter-resolution simulated-natural-color image of Hawaii. Vegetation is generally green, with...

  20. USGS Small-scale Dataset - Satellite View of Hawaii 200603 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of Hawaii map layer is a 200-meter-resolution simulated-natural-color image of Hawaii. Vegetation is generally green, with forests in darker green...

  1. USGS Small-scale Dataset - Satellite View of Alaska, with Shaded Relief 200605 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of Alaska, with Shaded Relief map layer is a 200- meter-resolution simulated-natural-color image of Alaska. Vegetation is generally green, with...

  2. USGS Small-scale Dataset - Satellite View of the Conterminous United States 200603 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of the Conterminous United States map layer is a 200- meter-resolution simulated-natural-color image of the United States. Vegetation is generally...

  3. USGS Small-scale Dataset - Satellite View of Alaska 200605 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of Alaska map layer is a 200-meter-resolution simulated-natural-color image of Alaska. Vegetation is generally green, with darker greens...

  4. Structural design and analysis of a solar array substrate for a GEO satellite

    OpenAIRE

    Safak, Omer

    2013-01-01

    The aim of this thesis is the design of solar array substrate for a geostationary satellite. The design of deployable solar array substrate is realized based on the requirements which are provided by BILUZAY (Bilkent University Space Technologies Research Centre). This array is going to empower a telecommunication satellite which will be operating in a geostationary orbit during 15 years. The main work presented in this thesis consists of two principal directions: solar cell array area dimens...

  5. Structural design and analysis of a solar array substrate for a GEO satellite

    OpenAIRE

    Safak, Omer

    2013-01-01

    The aim of this thesis is the design of solar array substrate for a geostationary satellite. The design of deployable solar array substrate is realized based on the requirements which are provided by BILUZAY (Bilkent University Space Technologies Research Centre). This array is going to empower a telecommunication satellite which will be operating in a geostationary orbit during 15 years. The main work presented in this thesis consists of two principal directions: solar cell array area dimens...

  6. Analysis of CO in the tropical troposphere using Aura satellite data and the GEOS-Chem model: insights into transport characteristics of the GEOS meteorological products

    Directory of Open Access Journals (Sweden)

    Junhua Liu

    2010-12-01

    Full Text Available We use the GEOS-Chem chemistry-transport model (CTM to interpret the spatial and temporal variations of tropical tropospheric CO observed by the Microwave Limb Sounder (MLS and the Tropospheric Emission Spectrometer (TES. In so doing, we diagnose and evaluate transport in the GEOS-4 and GEOS-5 assimilated meteorological fields that drive the model, with a particular focus on vertical mixing at the end of the dry season when convection moves over the source regions. The results indicate that over South America, deep convection in both GEOS-4 and GEOS-5 decays at too low an altitude early in the wet season, and the source of CO from isoprene in the model (MEGAN v2.1 is too large, causing a lag in the model's seasonal maximum of CO compared to MLS CO in the upper troposphere (UT. TES and MLS data reveal problems with excessive transport of CO to the eastern equatorial Pacific and lofting in the ITCZ in August and September, particularly in GEOS-4. Over southern Africa, GEOS-4 and GEOS-5 simulations match the phase of the observed CO variation from the lower troposphere (LT to the UT fairly well, although the magnitude of the seasonal maximum is underestimated considerably due to low emissions in the model. A sensitivity run with increased emissions leads to improved agreement with observed CO in the LT and middle troposphere (MT, but the amplitude of the seasonal variation is too high in the UT in GEOS-4. Difficulty in matching CO in the LT and UT implies there may be overly vigorous vertical mixing in GEOS-4 early in the wet season. Both simulations and observations show a time lag between the peak in fire emissions (July and August and in CO (September and October. We argue that it is caused by the prevailing subsidence in the LT until convection moves south in September, as well as the low sensitivity of TES data in the LT over the African Plateau. The MLS data suggest that too much CO has been transported from fires in northern Africa to the UT

  7. Interpretations of de-orbit, deactivation, and shutdown guidelines applicable to GEO satellites

    Science.gov (United States)

    Honda, L.; Perkins, J.; Sun, Sheng

    As the population of space debris in orbit around the Earth grows, the probability for catastrophic collisions increases. Many agencies such as the IADC, FCC, and UN have proposed space debris mitigation guidelines or recommendations. For example, a minimum increase in perigee altitude of 235km + (1000 Cr A / m) where Cr is the solar radiation pressure coefficient, A/m is the aspect area to dry mass ratio, and 235 km is the sum of the upper altitude of the geostationary orbit (GEO) protected region (200 km) and the maximum descent of a re-orbited spacecraft due to lunar-solar & geopotential perturbations (35 km) with an eccentricity less than or equal to 0.003. While this particular recommendation is reasonably straightforward, the assumptions an operator chooses may change the result by 25 km. Other recommendations are more ambiguous. For example, once the space vehicle has been de-orbited to the required altitude, all on-board stored energy sources must be discharged by venting propellants and pressurants, discharging batteries and disabling the ability to charge them, and performing other appropriate measures. “ Vented” is not usually defined. In addition, the broadcasting capability of the spacecraft must be disabled. Boeing and its customers are working together to devise de-orbit and deactivation sequences that meet the spirit of the recommendations. This paper derives and proposes a generic minimum deorbit altitude, appropriate depletion and venting pressures based on tank design, propellant and pressurant type, and an acceptable shutdown procedure and final configuration that avoid interference with those still in the GEO belt well into the future. The goal of this paper is to open a dialogue with the global community to establish reasonable guidelines that are straightforward, safe, and achievable before an absolute requirement is set.

  8. Constraints on ship NOx emissions in Europe using GEOS-Chem and OMI satellite NO2 observations

    Directory of Open Access Journals (Sweden)

    G. C. M. Vinken

    2013-07-01

    Full Text Available We present a top-down ship NOx emission inventory for the Baltic Sea, North Sea, Bay of Biscay and Mediterranean Sea, based on satellite observed tropospheric NO2 columns of the Ozone Monitoring Instrument (OMI for 2005–2006. We improved the representation of ship emissions in the GEOS-Chem chemistry transport model, and compared simulated NO2 columns to consistent satellite observations. Relative differences between simulated and observed NO2 columns have been used to constrain ship emissions in four European seas (Baltic Sea, North Sea, Bay of Biscay and Mediterranean Sea. The constrained ship tracks account for 39% of total top-down European ship NOx emissions, which amounts to 0.96 Tg N for 2005, and 1.0 Tg N for 2006 (11–15% lower than the bottom-up EMEP ship emission inventory. Our results indicate that EMEP emissions in the Mediterranean Sea are too high (by 60% and misplaced by up to 150 km, which can have important consequences for local air quality simulations. In the North Sea, our top-down emissions amount to 0.05 Tg N for 2005 (35% lower than EMEP. Increased top-down emissions were found for the Baltic Sea and Bay of Biscay, with emission totals of 0.05 Tg N (131% higher than EMEP and 0.08 Tg N for 2005 (128% higher than EMEP, respectively. Our study explicitly accounts for the (non-linear sensitivity of satellite retrievals to changes in the a priori NO2 profiles. Although the effect of this sensitivity might be minor for small emission increments, our findings stress the need for consistent information in satellite retrieval and model, as satellite observations are never fully independent of model information (i.e. assumptions on vertical NO2 profiles. Our study provides for the first time a space-based top-down ship NOx emission inventory, and can serve as a framework for future studies to constrain ship emissions using satellite NO2 observations in other seas.

  9. Radiation Environment at GEO from the FY2G Satellite Observations

    Science.gov (United States)

    Wang, C.

    2016-12-01

    WANG Chun-Qin1,2*, Zhang Shen-Yi1,2 Jing Tao1,2, Zhang Huan-Xin1,2 Li Jia-Wei3 Zhang Xiao-Xin3 Sun Yue-Qiang1,2 Liang Jin-Bao1,2 Wei Fei1,2 Shen Guo-Hong1,2 Huang Cong3 Shi Chun-Yan1,21.National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China; 2.Beijing Key Laboratory of Space Environment Exploration, Beijing 100190,China 3.National Satellite Meteorological Center, National Center for Space Weather, Beijing 100081, China; Abstract Recent measurements of the high energy electrons and protons with energetic particle instrument carried on the FY-2G satellite are presented. The instrument consist of two detectors-the high energy electrons instrument which can measure 200keV to greater than 4MeV electrons with eleven channels, and the high energy protons and heavy ions instrument which mainly senses incident flux of solar protons with seven channels from 4MeV to 300 MeV. The paper shows electrons and protons observations from Jan 2015 until Oct 2015. A precise description and preliminary analysis of particle dynamic during disturbances of magnetic storms、substorms and solar eruptions suggest that both of the detectors show accurate response to various disturbances and provide refined particles data. Comparison results of FY2G satellite with GOES series satellites reflect obvious local difference in particle flux evolvement especially during intensive disturbances time, which can be helpful for data assimilation of multi-satellite as well as further research in more complicated magnetosphere energy particle dynamic.

  10. TCP-ADaLR: TCP with adaptive delay and loss response for broadband GEO satellite networks

    OpenAIRE

    Omueti, Modupe Omogbohun

    2007-01-01

    Transmission Control Protocol (TCP) performance degrades in broadband geostationary satellite networks due to long propagation delays and high bit error rates. In this thesis, we propose TCP with algorithm modifications for adaptive delay and loss response (TCP-ADaLR) to improve TCP performance. TCP-ADaLR incorporates delayed acknowledgement mechanism recommended for Internet hosts. We evaluate and compare the performance of TCP-ADaLR, TCP SACK, and TCP NewReno, with and without delayed ackno...

  11. Single-event and total-dose effects in geo-stationary transfer orbit during solar-activity maximum period measured by the Tsubasa satellite

    Science.gov (United States)

    Koshiishi, H.; Kimoto, Y.; Matsumoto, H.; Goka, T.

    The Tsubasa satellite developed by the Japan Aerospace Exploration Agency was launched in Feb 2002 into Geo-stationary Transfer Orbit GTO Perigee 500km Apogee 36000km and had been operated well until Sep 2003 The objective of this satellite was to verify the function of commercial parts and new technologies of bus-system components in space Thus the on-board experiments were conducted in the more severe radiation environment of GTO rather than in Geo-stationary Earth Orbit GEO or Low Earth Orbit LEO The Space Environment Data Acquisition equipment SEDA on board the Tsubasa satellite had the Single-event Upset Monitor SUM and the DOSimeter DOS to evaluate influences on electronic devices caused by radiation environment that was also measured by the particle detectors of the SEDA the Standard DOse Monitor SDOM for measurements of light particles and the Heavy Ion Telescope HIT for measurements of heavy ions The SUM monitored single-event upsets and single-event latch-ups occurred in the test sample of two 64-Mbit DRAMs The DOS measured accumulated radiation dose at fifty-six locations in the body of the Tsubasa satellite Using the data obtained by these instruments single-event and total-dose effects in GTO during solar-activity maximum period especially their rapid changes due to solar flares and CMEs in the region from L 1 1 through L 11 is discussed in this paper

  12. Assessing the Impact of Advanced Satellite Observations in the NASA GEOS-5 Forecast System Using the Adjoint Method

    Science.gov (United States)

    Gelaro, Ron; Liu, Emily; Sienkiewicz, Meta

    2011-01-01

    The adjoint of a data assimilation system provides a flexible and efficient tool for estimating observation impacts on short-range weather forecasts. The impacts of any or all observations can be estimated simultaneously based on a single execution of the adjoint system. The results can be easily aggregated according to data type, location, channel, etc., making this technique especially attractive for examining the impacts of new hyper-spectral satellite instruments and for conducting regular, even near-real time, monitoring of the entire observing system. In this talk, we present results from the adjoint-based observation impact monitoring tool in NASA's GEOS-5 global atmospheric data assimilation and forecast system. The tool has been running in various off-line configurations for some time, and is scheduled to run as a regular part of the real-time forecast suite beginning in autumn 20 I O. We focus on the impacts of the newest components of the satellite observing system, including AIRS, IASI and GPS. For AIRS and IASI, it is shown that the vast majority of the channels assimilated have systematic positive impacts (of varying magnitudes), although some channels degrade the forecast. Of the latter, most are moisture-sensitive or near-surface channels. The impact of GPS observations in the southern hemisphere is found to be a considerable overall benefit to the system. In addition, the spatial variability of observation impacts reveals coherent patterns of positive and negative impacts that may point to deficiencies in the use of certain observations over, for example, specific surface types. When performed in conjunction with selected observing system experiments (OSEs), the adjoint results reveal both redundancies and dependencies between observing system impacts as observations are added or removed from the assimilation system. Understanding these dependencies appears to pose a major challenge for optimizing the use of the current observational network and

  13. Analysis of Satellite Network Architecture based on GEO/LEO Constellation%基于GEO/LEO两层星座的卫星组网结构分析

    Institute of Scientific and Technical Information of China (English)

    何俊; 易先清

    2009-01-01

    提出了一种基于GEO/LEO两层星座的卫星组网结构,在两层星座中建立了立体交叉的层内、层间星际链路,实现了GEO/LEO两层卫星星座的优势互补,具有组网灵活、管理简单等特点.通过快照周期定义了星座中各卫星的逻辑位置,并基于逻辑位置提出了对LEO卫星的分群和分组管理:包括LEO卫星的逻辑分群,群内LEO卫星的分组,以及分组内组长LEO卫星的选取和备份机制.在该卫星组网结构中,各星座协同运行,数据传输方式多样,能提高卫星网络的性能.

  14. Towards an Automatic Framework for Urban Settlement Mapping from Satellite Images: Applications of Geo-referenced Social Media and One Class Classification

    Science.gov (United States)

    Miao, Zelang

    2017-04-01

    Currently, urban dwellers comprise more than half of the world's population and this percentage is still dramatically increasing. The explosive urban growth over the next two decades poses long-term profound impact on people as well as the environment. Accurate and up-to-date delineation of urban settlements plays a fundamental role in defining planning strategies and in supporting sustainable development of urban settlements. In order to provide adequate data about urban extents and land covers, classifying satellite data has become a common practice, usually with accurate enough results. Indeed, a number of supervised learning methods have proven effective in urban area classification, but they usually depend on a large amount of training samples, whose collection is a time and labor expensive task. This issue becomes particularly serious when classifying large areas at the regional/global level. As an alternative to manual ground truth collection, in this work we use geo-referenced social media data. Cities and densely populated areas are an extremely fertile land for the production of individual geo-referenced data (such as GPS and social network data). Training samples derived from geo-referenced social media have several advantages: they are easy to collect, usually they are freely exploitable; and, finally, data from social media are spatially available in many locations, and with no doubt in most urban areas around the world. Despite these advantages, the selection of training samples from social media meets two challenges: 1) there are many duplicated points; 2) method is required to automatically label them as "urban/non-urban". The objective of this research is to validate automatic sample selection from geo-referenced social media and its applicability in one class classification for urban extent mapping from satellite images. The findings in this study shed new light on social media applications in the field of remote sensing.

  15. GeoComp-n, an advanced system for the processing of coarse and medium resolution satellite data. Part 2: biophysical products for Northern ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Cihlar, J. [Canada Centre for Remote Sensing, Natural Resources Canada, Ottawa, Ontario (Canada); Chen, J. [Canada Centre for Remote Sensing, Natural Resources Canada, Ottawa, Ontario (Canada); Univ. of Toronto, Dept. of Geography, Toronto, Ontario (Canada); Li, Z. [Canada Centre for Remote Sensing, Natural Resources Canada, Ottawa, Ontario (Canada); Univ. of Maryland, Dept of Meteorology, College Park, MD (United States)] [and others

    2002-02-01

    Effective use of satellite data for environmental monitoring requires consistent, high-throughput processing of large volumes of data as it is transformed from raw measurements to useful higher level products. 'GeoComp-n', the next generation of the Geocoding and Compositing System developed at the Canada Centre for Remote Sensing, Natural Resources Canada, was developed as a software solution to this challenge, for use with satellites that provide daily data for the landmass of Canada or comparably large areas. In this paper, the authors discuss the characteristics of the algorithms and methods used in the generation of GeoComp-n products. The theoretical basis and assumptions in the algorithms are described, and the quality of the products is discussed based on validation studies. Examples of a suite of products for Canada during one 10-day period illustrate the diversity and quality of observations for the terrestrial biosphere that may be derived frequently and over large areas from satellites. Issues related to quality assessment in a production environment are also discussed. (author)

  16. GEO中高分辨率民用光学对地观测卫星发展研究%Development Analysis on GEO Civil Optical Earth Observation Satellites with Mid-high Resolution

    Institute of Scientific and Technical Information of China (English)

    于龙江; 刘云鹤

    2013-01-01

    The development of state-of-art GEO civil optical earth observation satellites with mid-high resolution is investigated, including COMS, GEO-Africa, GEO-Oculus, etc. The mission and main functions of these satellites are analyzed. The system level design and main technology approach of these satellites are summarized and compared. Finally, several issues that are important in GEO mid-high resolution civil optical earth observation satellites technology are discussed, such as selection of focal detector, high stability attitude control, jitter rejection, heat management in the night, etc. The research results could be instructions to the development of China's GEO civil optical earth observation satellites with mid-high resolution.%调研了国外地球静止轨道(GEO)中高分辨率民用光学对地观测卫星的发展情况,其中包括“通信海洋-气象卫星”(COMS)、GEO-Africa和GEO-Oculus等卫星;分析了卫星的任务范围和主要功能;对卫星总体设计方案和采用的主要技术途径进行了归纳和对比.对发展GEO中高分辨率民用光学对地观测卫星需要注意的探测器选型、高稳定度姿态控制、微振动抑制、夜晚阶段的热控等相关问题进行了分析,可为中国发展同类卫星提供参考.

  17. Geo-spatial distribution of cloud cover and influence of cloud induced attenuation and noise temperature on satellite signal propagation over Nigeria

    Science.gov (United States)

    Ojo, Joseph Sunday

    2017-05-01

    The study of the influence of cloud cover on satellite propagation links is becoming more demanding due to the requirement of larger bandwidth for different satellite applications. Cloud attenuation is one of the major factors to consider for optimum performance of Ka/V and other higher frequency bands. In this paper, the geo-spatial distribution of cloud coverage over some chosen stations in Nigeria has been considered. The substantial scale spatial dispersion of cloud cover based on synoptic meteorological data and the possible impact on satellite communication links at higher frequency bands was also investigated. The investigation was based on 5 years (2008-2012) achieved cloud cover data collected by the Nigerian Meteorological Agency (NIMET) Federal Ministry of Aviation, Oshodi Lagos over four synoptic hours of the day covering day and night. The performances of satellite signals as they traverse through the cloud and cloud noise temperature at different seasons and over different hours of days at Ku/W-bands frequency are also examined. The overall result shows that the additional total atmospheric noise temperature due to the clear air effect and the noise temperature from the cloud reduces the signal-to-noise ratio of the satellite receiver systems, leading to more signal loss and if not adequately taken care of may lead to significant outage. The present results will be useful for Earth-space link budgeting, especially for the proposed multi-sensors communication satellite systems in Nigeria.

  18. Spatial heterogeneity in mangroves assessed by GeoEye-1 satellite data: a case-study in Zhanjiang Mangrove National Nature Reserve (ZMNNR), China

    Science.gov (United States)

    Leempoel, K.; Bourgeois, C.; Zhang, J.; Wang, J.; Chen, M.; Satyaranayana, B.; Bogaert, J.; Dahdouh-Guebas, F.

    2013-02-01

    Mangrove forests, which are declining across the globe mainly because of human intervention, require an evaluation of their past and present status (e.g. areal extent, species-level distribution, etc.) to better implement conservation and management strategies. In this paper, mangrove cover dynamics at Gaoqiao (under the jurisdiction of Zhanjiang Mangrove National Nature Reserve - ZMNNR, P. R. China) were assessed through time using 1967 (Corona KH-4B), 2000 (Landsat ETM+), and 2009 (GeoEye-1) satellite imagery. An important decline in mangrove cover (-36%) was observed between 1967 and 2009 due to dike construction for agriculture (paddy) and aquaculture practices. Moreover, dike construction prevented mangroves from expanding landward. Although a small increase of mangrove area was observed between 2000 and 2009 (+24%), the ratio mangrove/aquaculture kept decreasing due to increased aquaculture at the expense of rice culture. In the land-use/cover map based on ground-truth data (5 m × 5 m plot-based tree measurements) (August-September, 2009) and spectral reflectance values (obtained from pansharpened GeoEye-1), both Bruguiera gymnorrhiza and small Aegiceras corniculatum are distinguishable at 73-100% accuracy, whereas tall A. corniculatum is identifiable at only 53% due to its mixed vegetation stands close to B. gymnorrhiza (classification accuracy: 85%). Sand proportion in the sediment showed significant differences (Kruskal-Wallis/ANOVA, P changes. Overall, the advantage of very high resolution satellite images like GeoEye-1 for mangrove spatial heterogeneity assessment and/or species-level discrimination is well demonstrated, along with the complexity to provide a precise classification for non-dominant species (e.g. Kandelia obovata) at Gaoqiao. Despite the limitations such as geometric distortion and single band information, the 42-yr old Corona declassified images are invaluable for land-use/cover change detections when compared to recent satellite data

  19. 轴角传感器对 GEO 卫星跟踪的影响分析%Analysis of Shaft Angle Sensor to the Influence for the GEO Satellite Tracking

    Institute of Scientific and Technical Information of China (English)

    吕鑫; 刘京

    2016-01-01

    在卫星导航系统的地面控制系统中使用桁架天线对 GEO 卫星进行跟踪。抛物面天线是地面运控系统的重要组成部分,主要任务是实现对卫星的自动跟踪,保证天线电轴始终准确的对准卫星。为了保证天线的指向精度普遍采用程序跟踪方式对 GEO 卫星进行跟踪。天线通过对比轴角传感器反馈的指向角度和系统解算出的程引角度形成闭环控制,使天线波束精确的指向卫星,保证地面设备与卫星之间的数据传递。本文针对轴角传感器由于其内部弹性结构和工作环境的原因易产生硬件形变,从而引起天线对卫星的跟踪异常,进而对卫星导航系统提供定位导航服务产生影响的问题。根据卫星运动的规律判断卫星异常和其运动位置的关系,分析出卫星载荷异常甚至失锁的故障原理,提出了调整天线偏置角度的应急处置方法。文中分别阐述了天线程序跟踪的原理和工作流程、轴角传感器的工作结构、产生形变后的影响分析和故障处理措施及效果。结论表明故障原理分析正确,应急处置措施可以保证天线所跟踪的卫星不失锁,导航信息传输的星地链路不中断。%Tracking of GEO satellites use truss antenna in the ground control system in satellite navigation sys-tem.Paraboloid antenna is an important part of ground operation control system,the main task is to realize the automatic tracking of the satellite,guarantee the electric axis antenna always accurate alignment of satellite.In order to ensure the anten-na pointing accuracy generally adopts the program tracking mode tracking of GEO satellites.Antenna by comparing the shaft angle sensor feedback pointing angle and system solutions are worked out process lead angle to form a closed loop control,let antenna beam accurate pointing the satellite,Guarantee between the ground equipment and satellite data transmission.The shaft angle

  20. Sources, seasonality, and trends of Southeast US aerosol: an integrated analysis of surface, aircraft, and satellite observations with the GEOS-Chem chemical transport model

    Directory of Open Access Journals (Sweden)

    P. S. Kim

    2015-07-01

    Full Text Available We use an ensemble of surface (EPA CSN, IMPROVE, SEARCH, AERONET, aircraft (SEAC4RS, and satellite (MODIS, MISR observations over the Southeast US during the summer-fall of 2013 to better understand aerosol sources in the region and the relationship between surface particulate matter (PM and aerosol optical depth (AOD. The GEOS-Chem global chemical transport model (CTM with 25 km × 25 km resolution over North America is used as a common platform to interpret measurements of different aerosol variables made at different times and locations. Sulfate and organic aerosol (OA are the main contributors to surface PM2.5 (mass concentration of PM finer than 2.5 μm aerodynamic diameter and AOD over the Southeast US. GEOS-Chem simulation of sulfate requires a missing oxidant, taken here to be stabilized Criegee intermediates, but which could alternatively reflect an unaccounted for heterogeneous process. Biogenic isoprene and monoterpenes account for 60 % of OA, anthropogenic sources for 30 %, and open fires for 10 %. 60 % of total aerosol mass is in the mixed layer below 1.5 km, 20 % in the cloud convective layer at 1.5–3 km, and 20 % in the free troposphere above 3 km. This vertical profile is well captured by GEOS-Chem, arguing against a high-altitude source of OA. The extent of sulfate neutralization (f = [NH4+]/(2[SO42−] + [NO3−] is only 0.5–0.7 mol mol−1 in the observations, despite an excess of ammonia present, which could reflect suppression of ammonia uptake by organic aerosol. This would explain the long-term decline of ammonium aerosol in the Southeast US, paralleling that of sulfate. The vertical profile of aerosol extinction over the Southeast US follows closely that of aerosol mass. GEOS-Chem reproduces observed total column aerosol mass over the Southeast US within 6 %, column aerosol extinction within 16 %, and space-based AOD within 21 %. The large AOD decline observed from summer to winter is driven by sharp declines in both

  1. CH4 and CO distributions over tropical fires during October 2006 as observed by the Aura TES satellite instrument and modeled by GEOS-Chem

    Science.gov (United States)

    Worden, J.; Wecht, K.; Frankenberg, C.; Alvarado, M.; Bowman, K.; Kort, E.; Kulawik, S.; Lee, M.; Payne, V.; Worden, H.

    2013-04-01

    Tropical fires represent a highly uncertain source of atmospheric methane (CH4) because of the variability of fire emissions and the dependency of the fire CH4 emission factors (g kg-1 dry matter burned) on fuel type and combustion phase. In this paper we use new observations of CH4 and CO in the free troposphere from the Aura Tropospheric Emission Sounder (TES) satellite instrument to place constraints on the role of tropical fire emissions versus microbial production (e.g. in wetlands and livestock) during the (October) 2006 El Niño, a time of significant fire emissions from Indonesia. We first compare the global CH4 distributions from TES using the GEOS-Chem model. We find a mean bias between the observations and model of 26.3 ppb CH4 that is independent of latitude between 50° S and 80° N, consistent with previous validation studies of TES CH4 retrievals using aircraft measurements. The slope of the distribution of CH4 versus CO as observed by TES and modeled by GEOS-Chem is consistent (within the TES observation error) for air parcels over the Indonesian peat fires, South America, and Africa. The CH4 and CO distributions are correlated between R = 0.42 and R = 0.46, with these correlations primarily limited by the TES random error. Over Indonesia, the observed slope of 0.13 (ppb ppb-1) ±0.01, as compared to a modeled slope of 0.153 (ppb ppb-1) ±0.005 and an emission ratio used within the GEOS-Chem model of approximately 0.11 (ppb ppb-1), indicates that most of the observed methane enhancement originated from the fire. Slopes of 0.47 (ppb ppb-1) ±0.04 and 0.44 (ppb ppb-1) ±0.03 over South America and Africa show that the methane in the observed air parcels primarily came from microbial-generated emissions. Sensitivity studies using GEOS-Chem show that part of the observed correlation for the Indonesian observations and most of the observed correlations over South America and Africa are a result of transport and mixing of the fire and nearby microbial

  2. CH4 and CO distributions over tropical fires as observed by the Aura TES satellite instrument and modeled by GEOS-Chem

    Science.gov (United States)

    Worden, J.; Wecht, K.; Frankenberg, C.; Alvarado, M.; Bowman, K.; Kort, E.; Kulawik, S.; Lee, M.; Payne, V.; Worden, H.

    2012-10-01

    Tropical fires represent a highly uncertain source of atmospheric methane (CH4) because of the variability of fire emissions and the dependency of the fire CH4 emission factors (g kg-1 dry matter burned) on fuel type and combustion phase. In this paper we use new observations of CH4 and CO in the free troposphere from the Aura Tropospheric Emission Sounder (TES) satellite instrument to place constraints on the role of tropical fire emissions versus microbial production (e.g. in wetlands and livestock) during the (October) 2006 El Nino, a time of significant peat fire emissions from Indonesia We first evaluate the global CH4 distributions from TES using the GEOS-Chem model. We find a mean bias between the observations and model of 26.3 ppb CH4 that is independent of latitude between 50° S and 80° N consistent with previous validation studies of TES CH4 retrievals using aircraft measurements. The slope of the distribution of CH4 versus CO as observed by TES and modeled by GEOS-Chem is consistent (within the TES observation error) for air parcels over the Indonesian peat fires, South America, and Africa. The CH4 and CO distributions are correlated between R = 0.42 and R = 0.46, with these correlations primarily limited by the TES random error. Over Indonesia, the observed slope of 0.13 (ppb ppb-1) ± 0.01, as compared to a modeled slop of 0.153 (ppb ppb-1) ± 0.005 and an emission ratio used within the GEOS-Chem model of approximately 0.11 (ppb ppb-1) indicates that most of the observed methane enhancement originated from the fire. Slopes of 0.47 (ppb ppb-1) ± 0.04 and 0.44 (ppb ppb-1) ± 0.03 over South America and Africa show that the methane in the observed air parcels primarily came from microbial generated emissions. Sensitivity studies using GEOS-Chem show that part of the observed correlation for the Indonesian observations and most of the observed correlations over South America and Africa are a result of transport and mixing of the fire and nearby

  3. Spatial heterogeneity in mangroves assessed by GeoEye-1 satellite data: a case-study in Zhanjiang Mangrove National Nature Reserve (ZMNNR, China

    Directory of Open Access Journals (Sweden)

    K. Leempoel

    2013-02-01

    Full Text Available Mangrove forests, which are declining across the globe mainly because of human intervention, require an evaluation of their past and present status (e.g. areal extent, species-level distribution, etc. to better implement conservation and management strategies. In this paper, mangrove cover dynamics at Gaoqiao (under the jurisdiction of Zhanjiang Mangrove National Nature Reserve – ZMNNR, P. R. China were assessed through time using 1967 (Corona KH-4B, 2000 (Landsat ETM+, and 2009 (GeoEye-1 satellite imagery. An important decline in mangrove cover (−36% was observed between 1967 and 2009 due to dike construction for agriculture (paddy and aquaculture practices. Moreover, dike construction prevented mangroves from expanding landward. Although a small increase of mangrove area was observed between 2000 and 2009 (+24%, the ratio mangrove/aquaculture kept decreasing due to increased aquaculture at the expense of rice culture. In the land-use/cover map based on ground-truth data (5 m × 5 m plot-based tree measurements (August–September, 2009 and spectral reflectance values (obtained from pansharpened GeoEye-1, both Bruguiera gymnorrhiza and small Aegiceras corniculatum are distinguishable at 73–100% accuracy, whereas tall A. corniculatum is identifiable at only 53% due to its mixed vegetation stands close to B. gymnorrhiza (classification accuracy: 85%. Sand proportion in the sediment showed significant differences (Kruskal-Wallis/ANOVA, P < 0.05 between the three mangrove classes (B. gymnorrhiza and small and tall A. corniculatum. Distribution of tall A. corniculatum on the convex side of creeks and small A.corniculatum on the concave side (with sand show intriguing patterns of watercourse changes. Overall, the advantage of very high resolution satellite images like GeoEye-1 for mangrove spatial heterogeneity assessment and/or species-level discrimination is well demonstrated

  4. GMTR: two-dimensional geo-fit multitarget retrieval model for michelson interferometer for passive atmospheric sounding/environmental satellite observations.

    Science.gov (United States)

    Carlotti, Massimo; Brizzi, Gabriele; Papandrea, Enzo; Prevedelli, Marco; Ridolfi, Marco; Dinelli, Bianca Maria; Magnani, Luca

    2006-02-01

    We present a new retrieval model designed to analyze the observations of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), which is on board the ENVironmental SATellite (ENVISAT). The new geo-fit multitarget retrieval model (GMTR) implements the geo-fit two-dimensional inversion for the simultaneous retrieval of several targets including a set of atmospheric constituents that are not considered by the ground processor of the MIPAS experiment. We describe the innovative solutions adopted in the inversion algorithm and the main functionalities of the corresponding computer code. The performance of GMTR is compared with that of the MIPAS ground processor in terms of accuracy of the retrieval products. Furthermore, we show the capability of GMTR to resolve the horizontal structures of the atmosphere. The new retrieval model is implemented in an optimized computer code that is distributed by the European Space Agency as "open source" in a package that includes a full set of auxiliary data for the retrieval of 28 atmospheric targets.

  5. A Numerical Testbed for Remote Sensing of Aerosols, and its Demonstration for Evaluating Retrieval Synergy from a Geostationary Satellite Constellation of GEO-CAPE and GOES-R

    Science.gov (United States)

    Wang, Jun; Xu, Xiaoguang; Ding, Shouguo; Zeng, Jing; Spurr, Robert; Liu, Xiong; Chance, Kelly; Mishchenko, Michael I.

    2014-01-01

    synergic use of two future geostationary satellites, GOES-R (Geostationary Operational Environmental Satellite R-series) and TEMPO (Tropospheric Emissions: Monitoring of Pollution). Strong synergy between GEOS-R and TEMPO are found especially in their characterization of surface bi-directional reflectance, and thereby, can potentially improve the AOD retrieval to the accuracy required by GEO-CAPE.

  6. USGS Small-scale Dataset - 100-Meter Resolution Satellite View of the Conterminous United States 201304 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of the Conterminous United States map layer is a 100-meter resolution simulated natural-color image of the United States. Vegetation is generally...

  7. USGS Small-scale Dataset - 100-Meter Resolution Satellite View with Shaded Relief of Alaska 201304 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View with Shaded Relief of Alaska map layer is a 100-meter resolution simulated natural-color image of Alaska, with relief shading added to accentuate...

  8. USGS Small-scale Dataset - 100-Meter Resolution Satellite View with Shaded Relief of Hawaii 201304 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View with Shaded Relief of Hawaii map layer is a 100-meter resolution simulated natural-color image of Hawaii, with relief shading added to accentuate...

  9. USGS Small-scale Dataset - Satellite View of the Conterminous United States, with Shaded Relief 200512 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of the Conterminous United States, with Shaded Relief map layer is a 200-meter-resolution simulated-natural-color image of the United States....

  10. LEO&GEO双层卫星网络的动态路由技术%Dynamic routing technique based on LEO&GEO double-layered satellite network

    Institute of Scientific and Technical Information of China (English)

    姚晔; 梁旭文

    2013-01-01

    基于低地球轨道和静止地球轨道(low Earth orbit & geo-synchronous Earth orbit,LEO & GEO)双层卫星网络结构,对其覆盖特性和星间链路(inter-satellite-link,ISL)特性进行了仿真分析.提出了分层分簇的管理方法,只有主簇头与GEO卫星有连接关系,简化了互联关系的复杂性.在该卫星组网结构中,利用星座网络拓扑的特点,提出一种负载均衡的动态路由算法,综合考虑了路径时延和ISL链路负载.与单层卫星网络相比,双层卫星网络可以更加均匀地分配通信量,仅在低层LEO卫星路由跳数超出一定阈值或者卫星网络链路利用率超过某个门限范围时,才利用上层GEO卫星进行中转传输,仿真结果表明,所提路由算法可以实现更低的时延、延迟抖动以及更优的服务质量性能.

  11. Cataloging LEO and GEO Objects Based on Metric Data Collected by a Single Satellite%基于单星测轨进行LEO和GEO目标编目

    Institute of Scientific and Technical Information of China (English)

    柳仲贵; 郝世锋

    2012-01-01

    Space-based surveillance has the advantage of high coverage and short time interval because it is beyond the limits of land, territory and weather. A self-contained space-based surveillance can not only improve the precision of space object orbits, but also support the catalog of important objects independently in the case of collapse of ground sensors. Therefore, it has high strategic and tactical value. To make up for the shortage of existing space-surveillance systems and to meet the requirements of self contained space-based surveillance, this paper presents a space-based surveillance design at an altitude of about 9 000 km, zero degree inclination and with seven visible spectrum sensors. Simulation shows that it can be self-contained to support catalog of LEO and GEO objects even with a single satellite.%针对既有天基探测的不足,本着降低卫星制造难度、使用复杂度,拓展监视对象的原则,针对编目测轨所需,论证设计了一个采用零倾角、9 000 km高度轨道,装有7个可见光探测器,以空域监视方式支持空间目标编目测轨的构想.该构想只需1颗卫星,即可形成空间目标编目所需的测轨,独立支持LEO(低地球轨道)和GEO(地球同步轨道)目标的编目管理,具有战略、战术双重价值.

  12. Spectral scattering inversion method of GEO satellite components%典型GEO卫星部件光谱散射特性反演方法

    Institute of Scientific and Technical Information of China (English)

    徐融; 赵飞

    2016-01-01

    The core of the satellite characteristics inversion based on mixed satellite spectra is the mathematical model and inversion algorithm. Theoretical model of spectral mixing was built with experiments conducted to justify the model. First, theoretical analysis of components’ spectral scattering model, linear spectral mixing model and unmixing methods of satellite’ s spectral data was conducted. Then, experiments were designed to measure and calibrate the spectral BRDF of a high-fidelity GEO satellite and its components, while the spectral scattering characteristics of component and material were discussed. Finally, nonnegative constrained least square methods were utilized to unmix the satellite’ s spectral data, with the largest relative residue less than 10%. Experiment results show that the linear spectral mixing model and nonnegative constrained least square unmixing methods have practical meaning in explaining spectral data of satellites and inversing satellite conditions.%由整星混合光谱反演卫星特征的核心在于数理模型及反演算法,基于此建立了光谱混合数理模型并进行了实验验证。首先,对部件光谱散射模型、线性光谱混合模型、整星光谱解混方法进行了理论分析;然后,设计实验定标测量了高保真GEO卫星模型及部件的光谱BRDF特性,讨论了部件和材料光谱散射特性的差别;最后,采用非负约束最小二乘法对卫星整体光谱进行了解混分析,最大相对残差小于10%。实验结果表明,线性光谱混合模型及非负约束最小二乘解混方法对于描述卫星光谱混合机理、反演卫星状态具有一定实用意义。

  13. Optimized High Temperature PEM Fuel Cell & High Pressure PEM Electrolyser for Regenerative Fuel Cell Systems in GEO Telecommunication Satellites

    Directory of Open Access Journals (Sweden)

    Farnes Jarle

    2017-01-01

    Full Text Available Next generation telecommunication satellites will demand increasingly more power. Power levels up to 50 kW are foreseen for the next decades. Battery technology that can sustain up to 50 kW for eclipse lengths of up to 72 minutes will represent a major impact on the total mass of the satellite, even with new Li-ion battery technologies. Regenerative fuel cell systems (RFCS were identified years ago as a possible alternative to rechargeable batteries. CMR Prototech has investigated this technology in a series of projects initiated by ESA focusing on both the essential fuel cell technology, demonstration of cycle performance of a RFCS, corresponding to 15 years in orbit, as well as the very important reactants storage systems. In the last two years the development has been focused towards optimising the key elements of the RFCS; the HTPEM fuel cell and the High Pressure PEM electrolyser. In these ESA activities the main target has been to optimise the design by reducing the mass and at the same time improve the performance, thus increasing the specific energy. This paper will present the latest development, including the main results, showing that significant steps have been taken to increase TRL on these key components.

  14. GEO portal

    Data.gov (United States)

    US Agency for International Development — The USAID GeoPortal is a new application that groups web-based capabilities for on-demand discovery of and access to geospatial content, services, expertise, and...

  15. Research and Application of GEO Satellite Spot-beam Covering Algorithm%GEO卫星点波束覆盖算法的研究与应用

    Institute of Scientific and Technical Information of China (English)

    董彦磊; 汪春霆; 孙巍

    2016-01-01

    GEO卫星点波束覆盖范围准确计算在实际工程应用中需求日益迫切,针对GEO卫星点波束覆盖特点,提出点波束平面覆盖和点波束球面覆盖计算方法。点波束平面覆盖计算是将地球看成一个平面利用平面几何公式计算点波束覆盖范围,点波束球面覆盖计算是将地球看成一个球体利用球面立体几何公式计算点波束覆盖范围。通过仿真、分析与比较,当点波束半功率角θ3dB较小时平面覆盖计算和球面覆盖计算精度都较高,当半功率角θ3dB较大时平面覆盖计算偏差明显增大,球面覆盖计算精度一直保持在较高水平。%Accurately calculating GEO satellite spot-beam coverage is demanded increasingly in the actual engineering applications.In view ofthe features of spot-beam coverage,this paper presents the algorithm of spot-beam plane coverage and spot-beam spherical coverage.The algorithm of spot-beam plane coverage takes the Earth as a flat to calculate spot-beam coverage with plane geometry formulas,and the algorithm of spot-beam sphere coverage takes the Earth as a sphere to calculate spot-beam coverage with three-dimensional geometry formulas.Through simulation,analysis and comparison,when the half-power angle of spot-beam is smaller,both plane coverage algorithm and spot-beam spherical coverage algorithm have high accuracy of calculation. When the half-power angle of spot-beam is bigger,the calculated deviation of spot-beam plane coverage algorithm increases significantly,however the calculation accuracy of spot-beam spherical coverage algorithm maintains at a high level.

  16. Satellite Based Education and Training in Remote Sensing and Geo-Information AN E-Learning Approach to Meet the Growing Demands in India

    Science.gov (United States)

    Raju, P. L. N.; Gupta, P. K.

    2012-07-01

    One of the prime activities of Indian Space Research Organisation's (ISRO) Space Program is providing satellite communication services, viz., television broadcasting, mobile communication, cyclone disaster warning and rescue operations etc. so as to improve their economic conditions, disseminate technical / scientific knowledge to improve the agriculture production and education for rural people of India. ISRO, along with National Aeronautical and Space Administration (NASA) conducted experimental satellite communication project i.e. Satellite Instructional Television Experiment (SITE) using NASA's Advanced Telecommunication Satellite (i.e. ATS 6) with an objective to educate poor people of India via satellite broadcasting in 1975 and 1976, covering more than 2600 villages in six states of India and territories. Over the years India built communication satellites indigenously to meet the communication requirements of India. This has further lead to launch of an exclusive satellite from ISRO for educational purposes i.e. EDUSAT in 2004 through which rich audio-video content is transmitted / received, recreating virtual classes through interactivity. Indian Institute of Remote Sensing (IIRS) established in 1966, a premier institute in south East Asia in disseminating Remote Sensing (RS) and Geographical Information System (GIS), mainly focusing on contact based programs. But expanded the scope with satellite based Distance Learning Programs for Universities, utilizing the dedicated communication satellite i.e. EDUSAT in 2007. IIRS conducted successfully eight Distance Learning Programs in the last five years and training more than 6000 students mainly at postgraduate level from more than 60 universities /Institutions spread across India. IIRS obtained feedback and improved the programs on the continuous basis. Expanded the scope of IIRS outreach program to train user departments tailor made in any of the applications of Remote Sensing and Geoinformation, capacity

  17. 采用伴随星接收LEO到GEO上行信号的一种方案%A Method Receiving Uplink Signal from LEO to GEO by Companion Satellites

    Institute of Scientific and Technical Information of China (English)

    万艳飞; 张军

    2005-01-01

    伴随卫星上部署动态跟踪天线,难以进行卫星姿态控制,为此提出了一种采用两颗伴随卫星部署非跟踪天线的接收方案,用于接收低轨圆轨道星(LEO)到地球同步静止卫星(GEO)的上行信号.理论分析及STK(Satellite Tool Kit)软件仿真结果表明,伴随星姿态只需在惯性空间内稳定,就可实现动态信号接收,大大降低了系统的实现难度.

  18. USGS Small-scale Dataset - 100-Meter Resolution Satellite View with Shaded Relief of the Conterminous United States 201304 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View with Shaded Relief of the Conterminous United States map layer is a 100-meter resolution simulated natural-color image of the United States, with...

  19. Satellite Thermal Infrared Earthquake Precursor to the Wenchuan Ms 8.0 Earthquake in Sichuan, China, and its Analysis on Geo-dynamics

    Institute of Scientific and Technical Information of China (English)

    WEI Lejun; GUO Jianfeng; LIU Jianhua; LU Zhenquan; LI Haibing; CAI Hui

    2009-01-01

    Based on an interpretation and study of the satellite remote-sensing images of FY-2C thermal infrared 1st wave band (10.3-11.3 μm) designed in China, the authors found that there existed obvious and isolated satellite thermal infrared anomalies before the 5.12 Wenchuan Ms 8.0 Earthquake. These anomalies had the following characteristics: (1) The precursor appeared rather early: on March 18, 2008, I.e., 55 days before the earthquake, thermal infrared anomalies began to occur; (2) The anomalies experienced quite many and complex evolutionary stages: the satellite thermal infrared anomalies might be divided into five stages, whose manifestations were somewhat different from each other. The existence of so many anomaly stages was probably observed for the first time in numerous cases of satellite thermal infrared research on earthquakes; (3) Each stage lasted quite a long time, with the longest one spanning 13 days; (4) An evident geothermal anomaly gradient was distributed along the Longmen seismic fracture zone, and such a phenomenon might also be discovered for the first time in satellite thermal infrared earthquake research. This discovery is therefore of great guiding and instructive significance in the study of the earthquake occurrence itself and the trend of the post-earthquake phenomena.

  20. Research of on-board mixed optical/electric switching of GEO broadband multimedia satellite%通信卫星光电混合交换技术研究

    Institute of Scientific and Technical Information of China (English)

    李瑞欣; 赵尚弘; 幺周石; 郑伟; 李勇军; 刘振霞

    2011-01-01

    On-board switching has been the development trend of satellite communication. There is electronic bottleneck in the development of on-board ATM switch, so the optical switch is the inevitable direction of future broadband multimedia satellite. The paper brings forward a scheme about on-board mixed optical/electronic switching of GEO, analyses the switching mode of the scheme, discusses the key techniques.%星上交换已成为卫星通信发展的趋势之一.星上ATM交换在发展过程中存在着电子瓶颈,星上光交换是未来宽带多媒体卫星的必然发展方向.提出了一种光电混合星上交换技术方案,对星上光交换的方式进行了分析,讨论了光电混合星上交换技术涉及的关键技术,对未来星上交换技术的发展进行了总结.

  1. Photometrical Observations "SBIRS GEO-2"

    Science.gov (United States)

    Sukhov, P. P.; Epishev, V. P.; Karpenko, G. F.; Sukhov, K. P.; Kudak, V. I.

    Photometrical observations GSS "SBIRS GEO 2" in B,V,R filters were carried near the equinoxes 2014-2015. Used velocity electrophotometer based on the FEU-79 in the pulse-counting mode. Received more than 25 light curves. From the known dimensions are defined; effective reflecting area - Sγλ, the spectral reflectance index - γλ, periods of light variation. Color-indices showed that in the reflected light flux from the GSS prevails "red" component. In the light curves are periodically dips and specular flash. This shows that GSS orbit is not in a static position specified triaxial orientation as in dynamic motion. Assumed following dynamics of the satellite "SBIRS GEO 2" in orbit. Helical scanning the Earth's surface visible infrared sensors satellite occurs with a period P1 = 15.66 sec. and swinging of the GSS about the direction of the motion vector of the satellite in an orbit with P2 = 62.64 sec., from the northern to the southern pole. Thus, during the period of swinging GSS going on 2 scan the visible part of the northern and southern hemispheres. In some dates observations dynamics work satellite in orbit changed.

  2. USGS Small-scale Dataset - 100-Meter Resolution Satellite View with Shaded Relief of Puerto Rico and the U.S. Virgin Islands 201304 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View with Shaded Relief of Puerto Rico and the U.S. Virgin Islands map layer is a 100-meter resolution simulated natural-color image of Puerto Rico and...

  3. USGS Small-scale Dataset - 100-Meter Resolution Satellite View of Puerto Rico and the U.S. Virgin Islands 201304 GeoTIFF

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Satellite View of Puerto Rico and the U.S. Virgin Islands map layer is a 100-meter resolution simulated natural-color image of Puerto Rico and the U.S. Virgin...

  4. Online Simulations of Global Aerosol Distributions in the NASA GEOS-4 Model and Comparisons to Satellite and Ground-Based Aerosol Optical Depth

    Science.gov (United States)

    Colarco, Peter; daSilva, Arlindo; Chin, Mian; Diehl, Thomas

    2010-01-01

    We have implemented a module for tropospheric aerosols (GO CART) online in the NASA Goddard Earth Observing System version 4 model and simulated global aerosol distributions for the period 2000-2006. The new online system offers several advantages over the previous offline version, providing a platform for aerosol data assimilation, aerosol-chemistry-climate interaction studies, and short-range chemical weather forecasting and climate prediction. We introduce as well a methodology for sampling model output consistently with satellite aerosol optical thickness (AOT) retrievals to facilitate model-satellite comparison. Our results are similar to the offline GOCART model and to the models participating in the AeroCom intercomparison. The simulated AOT has similar seasonal and regional variability and magnitude to Aerosol Robotic Network (AERONET), Moderate Resolution Imaging Spectroradiometer, and Multiangle Imaging Spectroradiometer observations. The model AOT and Angstrom parameter are consistently low relative to AERONET in biomass-burning-dominated regions, where emissions appear to be underestimated, consistent with the results of the offline GOCART model. In contrast, the model AOT is biased high in sulfate-dominated regions of North America and Europe. Our model-satellite comparison methodology shows that diurnal variability in aerosol loading is unimportant compared to sampling the model where the satellite has cloud-free observations, particularly in sulfate-dominated regions. Simulated sea salt burden and optical thickness are high by a factor of 2-3 relative to other models, and agreement between model and satellite over-ocean AOT is improved by reducing the model sea salt burden by a factor of 2. The best agreement in both AOT magnitude and variability occurs immediately downwind of the Saharan dust plume.

  5. GEO-GEO Cross-Calibration Results for AE9 Development

    Science.gov (United States)

    2014-02-18

    1 - 1. INTRODUCTION This document summarizes cross calibration of energetic electron observations between pairs of LANL geosynchronous (GEO... document reviews cross calibration between various pairings of LANL GEO satellites. Data are available from seven Synchronous Orbit Particle Analyzer...specifications, or other data included in this document for any purpose other than Government procurement does not in any way obligate the U.S. Government

  6. Single-baseline-interferometry-based Orbit Measurement and Determination Test of GEO Satellite%基于单基线干涉测量的GEO卫星轨道测定与验证

    Institute of Scientific and Technical Information of China (English)

    任天鹏; 曹建峰; 唐歌实; 戴一堂; 陈略; 孙靖; 韩松涛; 路伟涛; 王美

    2016-01-01

    As a kind of passive measurement, the interferometry has a natural advantage to track a non-cooperative spatial target. Through applying a 5.5km-baseline interferometry system, a differential interferometry test is done on a GEO satellite. After introducing group-delay-aided phase delay, the measured noise of the interferometry delay is about 9.4ps (root mean square of the linear fitting residuals in each 300 seconds). Following a differential observation as "2-hour-calibration~13-hour-tracking~2-hour-calibration", the accuracy of the interferometry delay is about 0.267ns (rms). The maximum difference between solved orbit and precise ephemeris is about 35.7km. Results show that the single-baseline interferometry can converge to the solution of GEO satellite orbit, which would bring a high-accuracy orbit even as passive monitoring.%干涉测量具有被动式测量特点,对空间非合作目标轨道监测具有天然优势.利用5.5公里基线干涉测量系统,针对GEO卫星开展了差分干涉测量实验.引入群时延辅助的相时延处理技术,GEO卫星干涉测量噪声约9.4ps.基于"2小时标校-13小时跟踪-2小时标校"的长时差分观测模式,GEO卫星干涉测量误差约0.267ns,定轨解算星历与精密星历最大径向偏差为35.7公里.结果表明,单基线干涉测量可以收敛解算GEO卫星轨道,实现较高精度的GEO卫星轨道被动式监测.

  7. Analysis of H2-Ni Battery Temperature Oscillation Mechanism for GEO Satellites%GEO卫星氢镍蓄电池在轨温度波动机理分析

    Institute of Scientific and Technical Information of China (English)

    刘百麟; 周佐新

    2011-01-01

    在某地球静止轨道通信卫星平台布局的基础上,通过合理地简化和假设建立了南蓄电池舱作为热分析计算模型,对影响蓄电池在轨温度波动的机理进行分析.分析结果表明:在冬至,西板、对地+Y板和背地+Y板受照外热流的日变化会引起其内表面温度大幅度波动,通过舱内热辐射又会引起服务舱南板等结构板内表面温度波动,而服务舱南板通过导热将引起安装其上的蓄电池温度波动,这是导致蓄电池温度波动的根本原因.%Based on the layout of the GEO communications satellites bus, the thermal math model (TMM) of south satellite battery cabin was presented to analyze the mathematical mechanism that influences battery temperature on orbit. It is shown that daily change of orbit heat flux will obviously influences the temperatures of west board, +Y panel of Earth deck and +Y panel of anti-Earth deck, and further influences the temperature of service module (SM) structure board through radiation, which induces the battery temperate variation through SM board conduction. This is the key reason of battery temperature variation.

  8. Geo-Information Logistical Modeling

    Directory of Open Access Journals (Sweden)

    Nikolaj I. Kovalenko

    2014-11-01

    Full Text Available This paper examines geo-information logistical modeling. The author illustrates the similarities between geo-informatics and logistics in the area of spatial objectives; illustrates that applying geo-data expands the potential of logistics; brings to light geo-information modeling as the basis of logistical modeling; describes the types of geo-information logistical modeling; describes situational geo-information modeling as a variety of geo-information logistical modeling.

  9. Potential of multispectral synergism for observing tropospheric ozone by combining IR and UV measurements from incoming LEO (EPS-SG) and GEO (MTG) satellite sensors

    Science.gov (United States)

    Costantino, Lorenzo; Cuesta, Juan; Emili, Emanuele; Coman, Adriana; Foret, Gilles; Dufour, Gaëlle; Eremenko, Maxim; Chailleux, Yohann; Beekmann, Matthias; Flaud, Jean-Marie

    2017-04-01

    Satellite observations offer a great potential for monitoring air quality on daily and global basis. However, measurements from currently in orbit sensors do not allow to probe surface concentrations of gaseous pollutants such as tropospheric ozone (Liu et al., 2010). Using single-band approaches based on spaceborne measurements of either thermal infrared radiance (TIR, Eremenko et al., 2008) or ultraviolet reflectance (UV, Liu et al., 2010) only ozone down to the lower troposphere (3 km) may be observed. A recent multispectral method (referred to as IASI+GOME-2) combining the information of IASI and GOME-2 (both onboard MetOp satellites) spectra, respectively from the TIR and UV, has shown enhanced sensitivity for probing ozone at the lowermost troposphere (LMT, below 3 km of altitude) with maximum sensitivity down to 2.20 km a.s.l. over land, while sensitivity for IASI or GOME-2 only peaks at 3 to 4 km at lowest (Cuesta et al., 2013). Future spatial missions will be launched in the upcoming years on both low and geostationary orbits, such as EPS-SG (EUMETSAT Polar System Second Generation) and MTG (Meteosat Third Generation), carrying respectively IASI-NG (for IR) and UVNS (for UV), and IRS (for IR) and UVN (Sentinel 4, for UV). This new-generation sensors will enhance the capacity to observe ozone pollution and particularly by synergism of multispectral measurements. In this work we develop a pseudo-observation simulator and evaluate the potential of future EPS-SG and MTG satellite observations, through IASI-NG+UVNS and IRS+UVN multispectral methods to observe near-surface O3. The pseudo-real state of atmosphere (nature run) is provided by MOCAGE (MOdèle de Chimie Atmosphérique à Grande Échelle) chemical transport model. Simulations are calibrated by careful comparisons with real data, to ensure the best coherence between pseudo-reality and reality, as well as between the pseudo-observation simulator and existing satellite products. We perform full and

  10. Development and Future of Typical Foreign GEO Satellite Mobile Communication Systems%卫星通信新技术专题讲座(一)第2讲国外典型GEO卫星移动通信系统发展概况及展望

    Institute of Scientific and Technical Information of China (English)

    陈锋; 郭道省; 杨龙

    2012-01-01

    GEO satellite communication system is one of the most important development field for its steady attitude, large coverage area, little Dopplershift, nature techniques and simple operation et al. Several advanced GEO satellite mobile communication systems, including In- marsat, Thuraya, Terrastar and Skyterra, and their characters and developing trends were de- tailedly introduced in this paper. The current development and the future trend of domestic GEO satellite mobile communication systems were also briefly described.%GEO卫星星体相对固定、覆盖面积大、多普勒频移小、技术相对成熟简单,是重要的卫星发展领域之一。文章重点介绍目前国际上比较先进的GEO卫星移动通信系统:Inmarsat、Thuraya、Terrastar和Skyterra,包括这些系统的特点和发展趋势,最后对我国GEO卫星移动通信系统的发展和趋势进行简单的描述。

  11. GeoCorps America

    Science.gov (United States)

    Dawson, M.

    2011-12-01

    GeoCorps America, a program of the Geological Society of America's (GSA) Education and Outreach Department, provides short-term geoscience jobs in America's most amazing public lands. These jobs are hosted on federal lands managed by GeoCorps' three partner agencies: the National Park Service (NPS), the U.S. Forest Service (USFS), and the Bureau of Land Management (BLM). Agency staff submit to GSA position descriptions that help meet their geoscience needs. GSA advertises the positions online, recruits applicants from its 24,000+ members, and coordinates the placement of the candidates selected by agency staff. The typical GeoCorps position lasts for three months, pays a stipend of $2,750, and provides either free housing or a housing allowance. Some GeoCorps positions are classified as "Guest Scientist" positions, which generally last longer, involve larger payments, and require a higher level of expertise. Most GeoCorps positions occur during the spring/summer, but an increasing number of positions are being offered during the fall/winter. GeoCorps positions are open to geoscientists of all levels, from undergraduates through retired professionals. GeoCorps projects involve field and laboratory-based geoscience research, but some projects focus on developing educational programs and materials for staff, volunteers, and the public. The subject areas covered by GeoCorps projects include geology, hydrology, paleontology, mapping/GIS, soils, geo-hazards, cave/karst science, and more. GeoCorps positions have taken place at over 125 different locations nationwide, including Grand Canyon National Park, Sierra National Forest, and Craters of the Moon National Monument. In 2011, GeoCorps began offering GeoCorps Diversity Internships and GeoCorps American Indian Internships. The introduction of these programs doubled the level of diversity among GeoCorps participants. This increase in diversity is helping GSA and its partner agencies in meeting its mutual goal of

  12. GeoServer cookbook

    CERN Document Server

    Iacovella, Stefano

    2014-01-01

    This book is ideal for GIS experts, developers, and system administrators who have had a first glance at GeoServer and who are eager to explore all its features in order to configure professional map servers. Basic knowledge of GIS and GeoServer is required.

  13. Development of Geo-Marketing

    Directory of Open Access Journals (Sweden)

    Tatiana Ozhereleva

    2014-10-01

    Full Text Available This article analyzes the state and development of geo-marketing. The author illustrates the multi-aspectedness of geo-marketing: applied technology and management technology. The article demonstrates that geo-marketing can be viewed as a reflection of the processes of co-evolution in society. The author brings to light the specifics of geo-marketing research and situational analysis in geo-marketing. The article describes applications of geo-marketing

  14. Development of Geo-Marketing

    OpenAIRE

    2014-01-01

    This article analyzes the state and development of geo-marketing. The author illustrates the multi-aspectedness of geo-marketing: applied technology and management technology. The article demonstrates that geo-marketing can be viewed as a reflection of the processes of co-evolution in society. The author brings to light the specifics of geo-marketing research and situational analysis in geo-marketing. The article describes applications of geo-marketing

  15. Hybrid-PIC simulation of Hall thruster plume shield on GEO satellites%GEO卫星霍尔推力器羽流防护结构混合PIC模拟

    Institute of Scientific and Technical Information of China (English)

    刘辉; 罗晓明; 温正; 王珏; 于达仁

    2016-01-01

    The plume of the Hall thruster has negative effects on cover glasses of the solar panel which have high light transmission.Therefore,it is necessary to design some protective structures for solar array. Firstly, some related works were reviewed. Then, two different protection schemes were simulated using hybrid-PIC for a GEO satellite equipped with a SPT100.Finally,the advantages and disadvantages of the two schemes were analyzed and some valuable suggestions were proposed.The output power of solar array will be decreased if they are polluted.%霍尔推力器应用于GEO卫星时,羽流会对太阳能翼板表面高透光玻璃盖片产生一定的影响,导致太阳能电池整体输入功率降低.因此,有必要针对羽流的影响对翼板表面进行一定的防护.在对目前国内外羽流安全性评估及防护方面的工作进行一定调研的基础上,针对SPT100应用于典型的GEO轨道卫星时的情况,利用SPIS软件运用混合单元粒子(PIC)方法模拟了两种可能的太阳能翼板羽流防护方案,并分析比较了每种方案的优缺点及防护效果,为推力器在轨飞行时的羽流防护提供一定的借鉴.

  16. GEO Supersites Data Exploitation Platform

    Science.gov (United States)

    Lengert, W.; Popp, H.-J.; Gleyzes, J.-P.

    2012-04-01

    In the framework of the GEO Geohazard Supersite initiative, an international partnership of organizations and scientists involved in the monitoring and assessment of geohazards has been established. The mission is to advance the scientific understanding of geohazards by improving geohazard monitoring through the combination of in-situ and space-based data, and by facilitating the access to data relevant for geohazard research. The stakeholders are: (1) governmental organizations or research institutions responsible for the ground-based monitoring of earthquake and volcanic areas, (2) space agencies and satellite operators providing satellite data, (3) the global geohazard scientific community. The 10.000's of ESA's SAR products are accessible, since beginning 2008, using ESA's "Virtual Archive", a Cloud Computing assets, allowing the global community an utmost downloading performance of these high volume data sets for mass-market costs. In the GEO collaborative context, the management of ESA's "Virtual Archive" and the ordering of these large data sets is being performed by UNAVCO, who is also coordinating the data demand for the several hundreds of co-PIs. ESA is envisaging to provide scientists and developers access to a highly elastic operational e-infrastructure, providing interdisciplinary data on a large scale as well as tools ensuring innovation and a permanent evolution of the products. Consequently, this science environment will help in defining and testing new applications and technologies fostering innovation and new science findings. In Europe, the collaboration between EPOS, "European Plate Observatory System" lead by INGV, and ESA with support of DLR, ASI, and CNES are the main institutional stakeholders for the GEO Supersites contributing also to a unifying e-infrastructure. The overarching objective of the Geohazard Supersites is: "To implement a sustainable Global Earthquake Observation System and a Global Volcano Observation System as part of the

  17. Dr.GEO

    Directory of Open Access Journals (Sweden)

    Francesca Campora

    2004-01-01

    Full Text Available Presentazione di Dr. Geo, un prodotto software Open Source progettato per lo studio interattivo della geometria euclidea piana e per un primo approccio ai fondamenti della programmazione in linguaggio Scheme.

  18. Xichang Satellite Launch Center

    Institute of Scientific and Technical Information of China (English)

    LiuJie

    2004-01-01

    Xichang Satellite Launch Center(XSLC) is mainly for geosynchronous orbit launches. The main purpose of XSLC is to launch spacecraft, such as broadcasting,communications and meteorological satellites, into geo-stationary orbit.Most of the commercial satellite launches of Long March vehicles have been from Xichang Satellite Launch Center. With 20 years' development,XSLC can launch 5 kinds of launch vehicles and send satellites into geostationary orbit and polar orbit. In the future, moon exploration satellites will also be launched from XSLC.

  19. Visible Light Spectroscopy of GEO Debris

    Science.gov (United States)

    Seitzer, Patrick; Lederer, Susan M.; Cowardin, Heather; Barker, Edwin S.; Abercromby, Kira J.

    2012-01-01

    Our goal is to understand the physical characteristics of debris at geosynchronous orbit (GEO). Our approach is to compare the observed reflectance as a function of wavelength with laboratory measurements of typical spacecraft surfaces to understand what the materials are likely to be. Because debris could be irregular in shape and tumbling at an unknown rate, rapid simultaneous measurements over a range of wavelengths are required. Acquiring spectra of optically faint objects with short exposure times to minimize these effects requires a large telescope. We describe optical spectroscopy obtained during 12-14 March 2012 with the IMACS imaging spectrograph on the 6.5-m 'Walter Baade' Magellan telescope at Las Campanas Observatory in Chile. When used in f/2 imaging mode for acquisition, this instrument has a field of view of 30 arc-minutes in diameter. After acquisition and centering of a GEO object, a 2.5 arc-second wide slit and a grism are moved into the beam for spectroscopy. We used a 200 l/mm grism blazed at 660 nm for wavelength coverage in the 500-900 nm region. Typical exposure times for spectra were 15-30 seconds. Spectra were obtained for five objects in the GEO regime listed as debris in the US Space Command public catalog, and one high area to mass ratio GEO object. In addition spectra were obtained of three cataloged IDCSP (Initial Defense Communications Satellite Program) satellites with known initial properties just below the GEO regime. All spectra were calibrated using white dwarf flux standards and solar analog stars. We will describe our experiences using Magellan, a telescope never used previously for orbital debris spectroscopy, and our initial results.

  20. High accuracy GNSS based navigation in GEO

    Science.gov (United States)

    Capuano, Vincenzo; Shehaj, Endrit; Blunt, Paul; Botteron, Cyril; Farine, Pierre-André

    2017-07-01

    Although significant improvements in efficiency and performance of communication satellites have been achieved in the past decades, it is expected that the demand for new platforms in Geostationary Orbit (GEO) and for the On-Orbit Servicing (OOS) on the existing ones will continue to rise. Indeed, the GEO orbit is used for many applications including direct broadcast as well as communications. At the same time, Global Navigation Satellites System (GNSS), originally designed for land, maritime and air applications, has been successfully used as navigation system in Low Earth Orbit (LEO) and its further utilization for navigation of geosynchronous satellites becomes a viable alternative offering many advantages over present ground based methods. Following our previous studies of GNSS signal characteristics in Medium Earth Orbit (MEO), GEO and beyond, in this research we specifically investigate the processing of different GNSS signals, with the goal to determine the best navigation performance they can provide in a GEO mission. Firstly, a detailed selection among different GNSS signals and different combinations of them is discussed, taking into consideration the L1 and L5 frequency bands, and the GPS and Galileo constellations. Then, the implementation of an Orbital Filter is summarized, which adaptively fuses the GN1SS observations with an accurate orbital forces model. Finally, simulation tests of the navigation performance achievable by processing the selected combination of GNSS signals are carried out. The results obtained show an achievable positioning accuracy of less than one meter. In addition, hardware-in-the-loop tests are presented using a COTS receiver connected to our GNSS Spirent simulator, in order to collect real-time hardware-in-the-loop observations and process them by the proposed navigation module.

  1. GEOS. User Tutorials

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Pengchen [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Settgast, Randolph R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Johnson, Scott M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Walsh, Stuart D.C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Morris, Joseph P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ryerson, Frederick J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-12-17

    GEOS is a massively parallel, multi-physics simulation application utilizing high performance computing (HPC) to address subsurface reservoir stimulation activities with the goal of optimizing current operations and evaluating innovative stimulation methods. GEOS enables coupling of di erent solvers associated with the various physical processes occurring during reservoir stimulation in unique and sophisticated ways, adapted to various geologic settings, materials and stimulation methods. Developed at the Lawrence Livermore National Laboratory (LLNL) as a part of a Laboratory-Directed Research and Development (LDRD) Strategic Initiative (SI) project, GEOS represents the culmination of a multi-year ongoing code development and improvement e ort that has leveraged existing code capabilities and sta expertise to design new computational geosciences software.

  2. The GEO600 project

    OpenAIRE

    Lück, H.; GEO600 Team,

    1997-01-01

    GEO600, an interferometric gravitational-wave detector with an arm length of 600 m, is currently being built in northern Germany close to Hannover. GEO600 incorporates an externally modulated fourfold delay-line Michelson interferometer giving a round-trip optical length of 2400 m. A master - slave combination of a monolithic diode-pumped Nd:YAG ring laser and an injection-locked amplifier will give a light power of about 10 W at a wavelength of 1064 nm. Power recycling increases the light po...

  3. Geo-neutrino review

    Energy Technology Data Exchange (ETDEWEB)

    Tolich, N., E-mail: ntolich@u.washington.edu [Center for Experimental Nuclear Physics and Astrophysics, and Departments of Physics, University of Washington, Seattle, WA, 98195 (United States)

    2012-08-15

    The principal source of energy for dynamic processes of the earth, such as plate tectonics is thought to come from the radioactive decays of {sup 238}U, {sup 232}Th, and {sup 40}K within the earth. These decays produce electron-antineutrinos, so-called geo-neutrinos, the measurement of which near the earth's surface allows for a direct measure of the total radiogenic heat production in the earth. The KamLAND and Borexino experiments have both measured a geo-neutrino flux significantly greater than zero. As shown in these proceedings, more precise future measurements will significantly constrain earth composition models.

  4. New Regional Satellite Positioning Constellation Scheme Discussion

    Institute of Scientific and Technical Information of China (English)

    CHU Hai-bin; ZHANG Nai-tong; GU Xue-mai

    2005-01-01

    The characteristics of present "Beidou" satellite positioning system are analyzed. In order to perfect our country regional satellite positioning system, the idea of "Beidou" geosychronous earth orbit (GEO) satellites combined with some middle earth orbit (MEO) satellites constellation is put forward. The details of general satellite constellation optimized method are described, using this method the multiple positioning constellation design results are gained. And those results belong to two type of schems, one is 2 GEO plus some MEO satellites and the other is 3 GEO plus some MEO satellites. Through simulation and comparison, among those multiple design results, final optimized regional positioning constellation is given. In order to check the chosen constellation cover performance, the position dilution of precision(PDOP) is calculated, and with satellite constellation simulation software Satlab many coverage performances of the chosen constellation substellar point track, elevation, azimuth and visible satellites number changing situation are also simulated.

  5. Living with geo-resources and geo-hazards

    NARCIS (Netherlands)

    Hangx, Suzanne; Niemeijer, André

    2015-01-01

    Two of the key strategic topics on the European Committee’s Horizon2020 Roadmap revolve around geo-resources and geo-hazards, and their impact on societal and economic development. On the way towards a better policy for sustainable geo-resources production, such as oil, gas, geothermal energy and gr

  6. Merging analytic and empirical GEO debris synchronization dynamics

    Science.gov (United States)

    Anderson, Paul V.; McKnight, Darren S.; Di Pentino, Frank; Schaub, Hanspeter

    2016-09-01

    The motion of abandoned satellites near the geostationary (GEO) region has been extensively studied, modeled, and compared to the motion of station-kept, operational satellites, providing insights into the evolution of uncontrolled orbits at GEO. Analytic developments produced a family of curves represented in the ascending node versus inclination space describing the long-term precession of the orbit plane at GEO, and forecasted the clustering of objects at the geopotential wells. However, recent investigations were undertaken to characterize apparent anomalistic behavior of GEO objects and classification of objects into related families. This paper provides a unifying summary of early bottom-up analytical theory with more recent top-down operational observations, highlighting the common linkage between these dimensions of GEO object behavior. This paper also identifies the relevance of these patterns of life tendencies for future operations at and near GEO, and discusses the long-term implications of these patterns of life for space situational awareness activities in this regime.

  7. SIMULATION AND ANALYSIS OF PERFORMANCE ON THE COMPASSTM ENHANCED BY GEO AND IGSO

    Institute of Scientific and Technical Information of China (English)

    Yang Sen; Huang Guoce

    2011-01-01

    Positioning accuracy of the Global Navigation Satellite System (GNSS) can be analyzed by Positioning Dilution Of Precision (PDOP).In order to enhance the navigating performance of Asia and the Pacific areas,this paper analyzes the next generation BeidouTM navigation satellite system (CompassTM) enhanced by Geostationary Earth Orbit (GEO) and Inclining GeoSynchronized Orbit (IGSO).As global navigation satellite system,CompassTM must be robust enough to avoid system layoff,when some nodes are not available.So,the CompassTM enhanced by GEO and IGSO constellation is proposed and analyzed its PDOP proformance,this paper shows some exciting results of performance of CompassTM enhanced by GEO and IGSO.From the simulation results,we can found that:when more than fifteen satellites are invalid,the enhanced system could be operating normally.

  8. A novel space-based observation strategy for GEO objects based on daily pointing adjustment of multi-sensors

    Science.gov (United States)

    Hu, Yun-peng; Li, Ke-bo; Xu, Wei; Chen, Lei; Huang, Jian-yu

    2016-08-01

    Space-based visible (SBV) program has been proved to be with a large advantage to observe geosynchronous earth orbit (GEO) objects. With the development of SBV observation started from 1996, many strategies have come out for the purpose of observing GEO objects more efficiently. However it is a big challenge to visit all the GEO objects in a relatively short time because of the distribution characteristics of GEO belt and limited field of view (FOV) of sensor. And it's also difficult to keep a high coverage of the GEO belt every day in a whole year. In this paper, a space-based observation strategy for GEO objects is designed based on the characteristics of the GEO belt. The mathematical formula of GEO belt is deduced and the evolvement of GEO objects is illustrated. There are basically two kinds of orientation strategies for most observation satellites, i.e., earth-oriented and inertia-directional. Influences of both strategies to their own observation regions are analyzed and compared with each other. A passive optical instrument with daily attitude-adjusting strategies is proposed to increase the daily coverage rate of GEO objects in a whole year. Furthermore, in order to observe more GEO objects in a relatively short time, the strategy of a satellite with multi-sensors is proposed. The installation parameters between different sensors are optimized, more than 98% of GEO satellites can be observed every day and almost all the GEO satellites can be observed every two days with 3 sensors (FOV: 6° × 6°) on the satellite under the strategy of daily pointing adjustment in a whole year.

  9. Why Geo-Humanities

    Science.gov (United States)

    Graells, Robert Casals i.; Sibilla, Anna; Bohle, Martin

    2016-04-01

    Anthropogenic global change is a composite process. It consists of societal processes (in the 'noosphere') and natural processes (in the 'bio-geosphere'). The 'noosphere' is the ensemble of social, cultural or political insights ('shared subjective mental concepts') of people. Understanding the composite of societal and natural processes ('human geo-biosphere intersections'), which shapes the features of anthropogenic global change, would benefit from a description that draws equally on natural sciences, social sciences and humanities. To that end it is suggested to develop a concept of 'geo-humanities': This essay presents some aspects of its scope, discussing "knowledge that is to manage", "intentions that are to shape", "choices that are to justify" and "complexity that is to handle". Managing knowledge: That people understand anthropogenic global change requires their insights into how 'human geosphere intersections' function. Insights are formed ('processed') in the noosphere by means of interactions between people. Understanding how 'human geosphere intersections' functions combines scientific, engineering and economic studies with studies of the dynamics of the noosphere. Shaping intentions: During the last century anthropogenic global change developed as the collateral outcome of humankind's accumulated actions. It is caused by the number of people, the patterns of their consumption of resources, and the alterations of their environments. Nowadays, anthropogenic global chance is either an intentional negligence or a conscious act. Justifying choices: Humanity has alternatives how to alter Earth at planetary scale consciously. For example, there is a choice to alter the geo-biosphere or to adjust the noosphere. Whatever the choice, it will depend on people's world-views, cultures and preferences. Thus beyond issues whether science and technology are 'sound' overarching societal issues are to tackle, such as: (i) how to appropriate and distribute natural

  10. Geo-neutrinos

    CERN Document Server

    Bellini, G; Ludhova, L; Mantovani, F; McDonough, W F

    2013-01-01

    We review a new interdisciplinary field between Geology and Physics: the study of the Earth's geo-neutrino flux. We describe competing models for the composition of the Earth, present geological insights into the make up of the continental and oceanic crust, those parts of the Earth that concentrate Th and U, the heat producing elements, and provide details of the regional settings in the continents and oceans where operating and planned detectors are sited. Details are presented for the only two operating detectors that are capable of measuring the Earth's geo-neutrinos flux: Borexino and KamLAND; results achieved to date are presented, along with their impacts on geophysical and geochemical models of the Earth. Finally, future planned experiments are highlighted.

  11. Geo Issue Tracking System

    Science.gov (United States)

    Khakpour, Mohammad; Paulik, Christoph; Hahn, Sebastian

    2016-04-01

    Communication about remote sensing data quality between data providers and users as well as between the users is often difficult. The users have a hard time figuring out if a product has known problems over their region of interest and data providers have to spend a lot of effort to make this information available, if it exists. Scientific publications are one tool for communicating with the users base but they are static and mostly one way. As a data provider it is also often difficult to make feedback, received from users, available to the complete user base. The Geo Issue Tracking System (GeoITS) is an Open Source Web Application which has been developed to mitigate these problems. GeoITS combines a mapping interface (Google Maps) with a simple wiki platform. It allows users to give region specific feedback on a remote sensing product by drawing a polygon on the map and describing the problems they had using the remote sensing product in this area. These geolocated wiki entries are then viewable by other users as well as the data providers which can modify and extend the entries. In this way the conversations between the users and the data provider are no longer hidden in e.g. emails but open for all users of the dataset. This new kind of communication platform can enable better cooperation between users and data providers. It will also provide data providers with the ability to track problems their dataset might have in certain areas and resolve them with new product releases. The source code is available via http://github.com/TUW-GEO/geoits_dev A running instance can be tried at https://geoits.herokuapp.com/

  12. Infrared Correlation Radiometer for GEO-CAPE

    Science.gov (United States)

    Neil, D. O.; Boldt, J.; Edwards, D. P.; Yee, J.

    2009-12-01

    We present our plans as part of NASA’s Instrument Incubator Program to characterize the performance of a 2.3 μm infrared correlation radiometer (IRCR) prototype subsystem for an instrument designed specifically to measure carbon monoxide (CO) from geostationary orbit. The Earth Science and Applications Decadal Survey mission GEO-CAPE specifies infrared correlation radiometry to measure CO in two spectral regions. CO measurements at 2.3 μm are uniformly sensitive throughout the troposphere, and 4.7 μm measurements are most sensitive to the free troposphere. In combination, the measurements yield information of this Criteria Pollutant near Earth's surface. The success of NASA’s Shuttle-based Measurement of Air Pollution from Satellites (MAPS) and Terra/MOPITT infrared gas correlation radiometers for CO measurements at 4.7 μm shifts the technology focus toward improving existing 2.3 μm CO measurement capability. GEO-CAPE uses this robust IRCR measurement technique at GEO, nearly 50 times farther away than the Terra/MOPITT orbit, to determine hourly changes in CO across a continental domain. We have structured the IRCR project around an analytical performance model to enable rapid evaluation of design specifics once the mission is defined. We present the architecture of the performance model, and the design of the simulator hardware and test plan which will populate the performance model.

  13. Multi-life cycles utilization of retired satellites

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Retired geosynchronous (GEO) communication satellites affect the GEO orbit environment in outer space. According to the new concept of modern design, the authors propose creatively a method of reusing retired GEO communication satellites, through adjusting retired GEO satellites to slightly inclined orbit geosynchronous (SIGSO) satellites. After these retired satellites are applied to the navigation and communication system, integrity of navigation system and positioning accuracy of the system is improved. Meanwhile, some transponders on these retired satellites can be used to establish a new satellite communication service, and initiate the study and utilization of the multi-life cycle for retired satellites. Experimental results show that this project has significant social value and can make remarkable economic benefit.

  14. Multi-life cycles utilization of retired satellites

    Institute of Scientific and Technical Information of China (English)

    SHI HuLi; AI GuoXiang; HAN YanBen; MA LiHua; CHEN JiBin; GENG JianPing

    2009-01-01

    Retired geosynchronous (GEO) communication satellites affect the GEO orbit environment in outer apace.According to the new concept of modern design,the authors propose creatively a method of reusing retired GEO communication satellites,through adjusting retired GEO satellites to slightly inclined orbit geosynchronous (SIGSO) satellites.After these retired satellites are applied to the navigation and communication system,integrity of navigation system and positioning accuracy of the system is improved.Meanwhile,some transponders on these retired satellites can be used to establish a new satellite communication service,and initiate the study and utilization of the multi-life cycle for retired satellites.Experimental results show that this project has significant social value and can make remarkable economic benefit.

  15. Meteorological satellite systems

    CERN Document Server

    Tan, Su-Yin

    2014-01-01

    “Meteorological Satellite Systems” is a primer on weather satellites and their Earth applications. This book reviews historic developments and recent technological advancements in GEO and polar orbiting meteorological satellites. It explores the evolution of these remote sensing technologies and their capabilities to monitor short- and long-term changes in weather patterns in response to climate change. Satellites developed by various countries, such as U.S. meteorological satellites, EUMETSAT, and Russian, Chinese, Japanese and Indian satellite platforms are reviewed. This book also discusses international efforts to coordinate meteorological remote sensing data collection and sharing. This title provides a ready and quick reference for information about meteorological satellites. It serves as a useful tool for a broad audience that includes students, academics, private consultants, engineers, scientists, and teachers.

  16. Theory of geostationary satellites

    CERN Document Server

    Zee, Chong-Hung

    1989-01-01

    Geostationary or equatorial synchronous satellites are a daily reminder of our space efforts during the past two decades. The nightly television satellite weather picture, the intercontinental telecommunications of television transmissions and telephone conversations, and the establishrnent of educational programs in remote regions on Earth are constant reminders of the presence of these satellites. As used here, the term 'geo­ stationary' must be taken loosely because, in the long run, the satellites will not remain 'stationary' with respect to an Earth-fixed reference frame. This results from the fact that these satellites, as is true for all satellites, are incessantly subject to perturbations other than the central-body attraction of the Earth. Among the more predominant pertur­ bations are: the ellipticity of the Earth's equator, the Sun and Moon, and solar radiation pressure. Higher harmonics of the Earth's potential and tidal effects also influence satellite motion, but they are of second­ order whe...

  17. The geo-neutrinos

    Directory of Open Access Journals (Sweden)

    Bellini G.

    2012-04-01

    Full Text Available The study of the antineutrinos emitted by the radioactive decays in the Earth interior is the only way to investigate how much of the terrestrial heat is produced by these decays and which is their contribution in the various Earth components. The existence of the geo-neutrinos has recently been demonstrated by Borexino and confirmed by Kamland. Kamland had found some hints already in 2005 and 2008 Nevertheless the statistics is not yet enough to discriminate among the various geological models.

  18. GEOS Atmospheric Model: Challenges at Exascale

    Science.gov (United States)

    Putman, William M.; Suarez, Max J.

    2017-01-01

    The Goddard Earth Observing System (GEOS) model at NASA's Global Modeling and Assimilation Office (GMAO) is used to simulate the multi-scale variability of the Earth's weather and climate, and is used primarily to assimilate conventional and satellite-based observations for weather forecasting and reanalysis. In addition, assimilations coupled to an ocean model are used for longer-term forecasting (e.g., El Nino) on seasonal to interannual times-scales. The GMAO's research activities, including system development, focus on numerous time and space scales, as detailed on the GMAO website, where they are tabbed under five major themes: Weather Analysis and Prediction; Seasonal-Decadal Analysis and Prediction; Reanalysis; Global Mesoscale Modeling, and Observing System Science. A brief description of the GEOS systems can also be found at the GMAO website. GEOS executes as a collection of earth system components connected through the Earth System Modeling Framework (ESMF). The ESMF layer is supplemented with the MAPL (Modeling, Analysis, and Prediction Layer) software toolkit developed at the GMAO, which facilitates the organization of the computational components into a hierarchical architecture. GEOS systems run in parallel using a horizontal decomposition of the Earth's sphere into processing elements (PEs). Communication between PEs is primarily through a message passing framework, using the message passing interface (MPI), and through explicit use of node-level shared memory access via the SHMEM (Symmetric Hierarchical Memory access) protocol. Production GEOS weather prediction systems currently run at 12.5-kilometer horizontal resolution with 72 vertical levels decomposed into PEs associated with 5,400 MPI processes. Research GEOS systems run at resolutions as fine as 1.5 kilometers globally using as many as 30,000 MPI processes. Looking forward, these systems can be expected to see a 2 times increase in horizontal resolution every two to three years, as well as

  19. Simulation of Telescope Detectivity for Geo Survey and Tracking

    Science.gov (United States)

    Richard, P.

    2014-09-01

    As the number of space debris on Earths Orbit increases steadily, the need to survey, track and catalogue them becomes of key importance. In this context, CNES has been using the TAROT Telescopes (Rapid Telescopes for Transient Objects owned and operated by CNRS) for several years to conduct studies about space surveillance and tracking. Today, two testbeds of services using the TAROT telescopes are running every night: one for GEO situational awareness and the second for debris tracking. Additionally to the CNES research activity on space surveillance and tracking domain, an operational collision avoidance service for LEO and GEO satellites is in place at CNES for several years. This service named CAESAR (Conjunction Analysis and Evaluation: Alerts and Recommendations) is used by CNES as well as by external customers. As the optical debris tracking testbed based on TAROT telescopes is the first step toward an operational provider of GEO measures that could be used by CAESAR, simulations have been done to help choosing the sites and types of telescopes that could be added in the GEO survey and debris tracking telescope network. One of the distinctive characteristics of the optical observation of space debris compared to traditional astronomic observation is the need to observe objects at low elevations. The two mains reasons for this are the need to observe the GEO belt from non-equatorial sites and the need to observe debris at longitudes far from the telescope longitude. This paper presents the results of simulations of the detectivity for GEO debris of various telescopes and sites, based on models of the GEO belt, the atmosphere and the instruments. One of the conclusions is that clever detection of faint streaks and spread sources by image processing is one of the major keys to improve the detection of debris on the GEO belt.

  20. The GEO600 project

    Science.gov (United States)

    Lück, H.; GEO600 Team

    1997-06-01

    GEO600, an interferometric gravitational-wave detector with an arm length of 600 m, is currently being built in northern Germany close to Hannover. GEO600 incorporates an externally modulated fourfold delay-line Michelson interferometer giving a round-trip optical length of 2400 m. A master - slave combination of a monolithic diode-pumped Nd:YAG ring laser and an injection-locked amplifier will give a light power of about 10 W at a wavelength of 1064 nm. Power recycling increases the light power inside the interferometer to a level of about 10 kW. The use of both power and signal recycling will yield a sensitivity of the same order of magnitude as the first stages of the other large-scale gravitational-wave detectors LIGO and VIRGO currently under construction. High signal recycling factors allow the sensitivity to be increased at a chosen frequency while reducing the bandwidth of the detector. This gives an advantage over broad-band detectors in detecting narrow-band periodic sources such as pulsars. The 25 cm diameter mirrors will be suspended as double pendulums from a platform supported by vibration-reduction systems. The passive filtering properties of this system sufficiently reduce the seismic noise in the frequency range of interest, i.e. 50 - 1000 Hz. The detector will start taking data in the year 2000.

  1. Geo-collaboration under stress

    NARCIS (Netherlands)

    Looije, R.; Brake, G.M. te; Neerincx, M.A.

    2007-01-01

    “Most of the science and decision making involved in geo-information is the product of collaborative teams. Current geospatial technologies are a limiting factor because they do not provide any direct support for group efforts. In this paper we present a method to enhance geo-collaboration by commun

  2. Geo-neutrinos: recent developments

    CERN Document Server

    Dye, Steve

    2014-01-01

    Radiogenic heating is a key component of the energy balance and thermal evolution of the Earth. It contributes to mantle convection, plate tectonics, volcanoes, and mountain building. Geo-neutrino observations estimate the present radiogenic power of our planet. This estimate depends on the quantity and distribution of heat-producing elements in various Earth reservoirs. Of particular geological importance is radiogenic heating in the mantle. This quantity informs the origin and thermal evolution of our planet. Here we present: currently reported geo-neutrino observations; estimates of the mantle geo-neutrino signal, mantle radiogenic heating, and mantle cooling; a comparison of chemical Earth model predictions of the mantle geo-neutrino signal and mantle radiogenic heating; a brief discussion of radiogenic heating in the core, including calculations of geo-neutrino signals per pW/kg; and finally a discussion of observational strategy.

  3. Optical and infrared transfer function of the GEOS 3 retroreflector array

    Science.gov (United States)

    Arnold, D. A.

    1975-01-01

    The transfer function of the retroreflector array carried by the Geos 3 satellite was computed at three wavelength: 5300, 6943, and 10600 A. The range correction is given for extrapolating laser range measurements to the center of gravity of the satellite. The reflectivity of the array was computed for estimating laser-echo signal strengths.

  4. GeoPower

    DEFF Research Database (Denmark)

    Kirsch, Reinhard; Balling, N.; Fuchs, Sven;

    Ziel des Projektes GeoPower ist es, verbesserte geologische Planungsgrundlagen für die Nutzung geothermischer Energie in der INTERREG-Region Südjütland - Schleswig zu erstellen und öffentlich verfügbar zu machen. Die effektivste Nutzung der Erdwärme erfolgt hydrothermal, d.h. durch die Förderung...... von heißem Tiefenwasser. Geologische Voraussetzung ist poröses oder geklüftetes wasserführendes Gestein im Tiefenbereich von 800 – 2.500 m. Es handelt sich hierbei um Sandsteine, deren Vorkommen, Tiefenlage und Mächtigkeit aufgrund des teilweise komplizierten Untergrundaufbaus in der Region lokal...... Planungsgrundlagen ist ein geologisches Modell der Region. In diesem Modell werden 12 Schichten des Untergrundes abgebildet, darunter auch die 3 hydrothermalen Reservoirkomplexe. Datengrundlage des Modells sind Bohrungen und die Ergebnisse reflexionsseismischer Messungen sowie bereits vorliegende Kartenwerke. Aus...

  5. Infrared Photometry of GEO Spacecraft with WISE

    Science.gov (United States)

    Lee, C.; Seitzer, P.; Cutri, R.; Grillmair, C.; Schildknecht, T.

    2016-09-01

    NASA launched the Wide-field Infrared Survey Explorer (WISE) into orbit on December 2009 with a mission to scan the entire sky in the infrared in four wavelength bands of 3.4, 4.6, 12, and 22 microns. WISE acquired data in the four bands for 10 months until the solid hydrogen cryogen was depleted and then proceeded to operate in the two shorter wavelength bands for an additional four months in a Post-Cryo phase. In its trove of data, WISE captured many streaks that were artificial satellites in orbit around Earth. We have examined a subset of equatorial WISE images with |declination| 30 degrees in order to minimize contamination of the satellite streaks by stars in the galactic plane. At least one streak of the length appropriate for a GEO station-keeping satellite appears in over 10% of these images. In bands 1 through 3 (for images 1016x1016 in size), the streaks are approximately 100 pixels in length, and in band 4 (for images 508x508 in size), the streaks are approximately 50 pixels in length. Most, but not all, of these spacecraft appear in all 4 wavelength bands. Since WISE is in a Sun-synchronous orbit pointed approximately radially away from the Earth at all times, all observations of GEO objects were obtained at a solar phase angle of approximately 90 degrees. We report on the color distributions of these detections and interpret the colors and compare the spacecraft colors with colors of other astronomical objects such as stars, galaxies, and asteroids that have appeared in previously published works on WISE data.

  6. Toward GEOS-6, A Global Cloud System Resolving Atmospheric Model

    Science.gov (United States)

    Putman, William M.

    2010-01-01

    NASA is committed to observing and understanding the weather and climate of our home planet through the use of multi-scale modeling systems and space-based observations. Global climate models have evolved to take advantage of the influx of multi- and many-core computing technologies and the availability of large clusters of multi-core microprocessors. GEOS-6 is a next-generation cloud system resolving atmospheric model that will place NASA at the forefront of scientific exploration of our atmosphere and climate. Model simulations with GEOS-6 will produce a realistic representation of our atmosphere on the scale of typical satellite observations, bringing a visual comprehension of model results to a new level among the climate enthusiasts. In preparation for GEOS-6, the agency's flagship Earth System Modeling Framework [JDl] has been enhanced to support cutting-edge high-resolution global climate and weather simulations. Improvements include a cubed-sphere grid that exposes parallelism; a non-hydrostatic finite volume dynamical core, and algorithm designed for co-processor technologies, among others. GEOS-6 represents a fundamental advancement in the capability of global Earth system models. The ability to directly compare global simulations at the resolution of spaceborne satellite images will lead to algorithm improvements and better utilization of space-based observations within the GOES data assimilation system

  7. GEO-LEO BI-SAR imaging algorithm%GEO-LEO双基地SAR成像算法研究

    Institute of Scientific and Technical Information of China (English)

    董众; 徐卓异; 张善从

    2014-01-01

    A Doppler distribution weighted method is proposed to solve the two-dimensional spectrum of GEO-LEO Bi-SAR imaging system. Different from the existing methods,this method deduces the corresponding analytical expression according to the physical significance of weight factor and the orbital parameters of GEO-LEO satellites. The solution difficulty of the two-di-mensional spectrum expression was overcome without any introducing errors. In combination with an Inverse Scaled Fast Fourier Transformation algorithm,the accurate ground target imaging of GEO-LEO Bi-SAR was realized. The simulation results show the advantages of the imaging method proposed in the paper.%提出一种基于多普勒贡献比加权的GEO-LEO星载双基地SAR二维频谱求解方法,与现有的频谱求解方法不同,该方法根据加权因子的物理意义,并利用GEO-LEO的轨道参数推导其相应的解析表达式,在没有引入误差的情况下,解决了GEO-LEO双基地SAR的二维频谱表达式求解问题。并与二维尺度变换逆FFT成像算法结合,实现了GEO-LEO双基地SAR对地面目标的精确成像。仿真实验结果表明了算法的优越性。

  8. EuroGeoSurveys

    Science.gov (United States)

    Demicheli, L.; Ludden, J. N.; Robida, F.

    2012-04-01

    In order to create safe, healthy and wealthy places to live in, it is vital that we understand our planet. At national level the collection of information on the state of the solid Earth and its processes is normally mandated to Geological Surveys. In fact, a Geological Survey is the national institution responsible for the geological inventory, monitoring, knowledge and research for the security, health and prosperity of the society. And EuroGeoSurveys (EGS) is the organisation representing the Geological Surveys from 33 countries around Europe. With one member for each country of the European Union and beyond, including the Russian Federation and Ukraine, the EGS network covers the whole continent. EGS'principal purpose is to provide geoscientific knowledge that underpins European policies and regulations for the benefit of society. Naturally, in our day-to-day activities, we contribute to the merging of economic, environmental and social agendas. Engaging a joint workforce of several thousands of geoscientists, also involving regional geological surveys in Germany, Italy and Spain, we strive to be the first body to be contacted when there is an international need for European geodata, or'geo-help'. For this reason we work on a daily basis with the EU institutions, and are considered the natural source of information on Earth science issues and relevant downstream applications in Europe. Our General Secretariat is based in the European Quarter of Brussels close to the European Commission, the EU Council, the European Parliament, and the political seat of NATO. Our operational strategy is based on the cooperation between national institutions, which enables to synergistically integrate both information and activities of our member organisations. This has allowed us to make significant progress over the years, permitting geology to become a topic deserving great attention on the European agenda. In order to enable a quick but high quality response to requests for

  9. Reflectance Spectra of Space Debris in GEO

    Science.gov (United States)

    Schildknecht, T.; Vannanti, A.; Krag, H.; Erd, C.

    The space debris environment in the Geostationary Earth Orbit (GEO) region is mostly investigated by means of optical surveys. Such surveys revealed a considerable amount of debris in the size range of 10 centimeter to one meter. Some of these debris exhibit particularly high area-to-mass ratios as derived from the evolution of their orbits. In order to understand the nature and eventually the origin of these objects, observations allowing to derive physical characteristics like size, shape and material are required. Information on the shape and the attitude motion of a debris piece may be obtained by photometric light curves. The most promising technique to investigate the surface material properties is reflectance spectroscopy. This paper discusses preliminary results obtained from spectrometric observations of space debris in GEO. The observations were acquired at the 1-meter ESA Space Debris Telescope (ESASDT) on Tenerife with a low-resolution spectrograph in the wavelength range of 450-960 nm. The target objects were space debris of different types with brightness as small as magnitude 15. Some simple-shaped, intact "calibration objects" with known surface materials like the MSG-2 satellites were also observed. The spectra show shape variations expected to be caused by the different physical properties of the objects. The determination of the possible materials is still in a preliminary phase. Limitations of the acquisition process of the spectra and the subsequent analysis are discussed. Future steps planned for a better characterization of the debris from the observed data are briefly outlined.

  10. The NASA GEOS-5 Aerosol Forecasting System

    Science.gov (United States)

    Colarco, Peter; daSilva, Arlindo; Darmenov, Anton

    2011-01-01

    The NASA Goddard Earth Observing System modeling and data assimilation environment (GEOS-5) is maintained by the Global Modeling and Assimilation Office (GMAO) at the NASA Goddard Space Flight Center. Near-realtime meteorological forecasts are produced to support NASA satellite and field missions. We have implemented in this environment an aerosol module based on the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) model. This modeling system has previously been evaluated in the context of hindcasts based on assimilated meteorology. Here we focus on the development and evaluation of the near-realtime forecasting system. We present a description of recent efforts to implement near-realtime biomass burning emissions derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) fire radiative power products. We as well present a developing capability for improvement of aerosol forecasts by assimilation of aerosol information from MODIS.

  11. The Impact of Horizontal and Temporal Resolution on Convection and Precipitation with High-Resolution GEOS-5

    Science.gov (United States)

    Putman, William P.

    2012-01-01

    Using a high-resolution non-hydrostatic version of GEOS-5 with the cubed-sphere finite-volume dynamical core, the impact of spatial and temporal resolution on cloud properties will be evaluated. There are indications from examining convective cluster development in high resolution GEOS-5 forecasts that the temporal resolution within the model may playas significant a role as horizontal resolution. Comparing modeled convective cloud clusters versus satellite observations of brightness temperature, we have found that improved. temporal resolution in GEOS-S accounts for a significant portion of the improvements in the statistical distribution of convective cloud clusters. Using satellite simulators in GEOS-S we will compare the cloud optical properties of GEOS-S at various spatial and temporal resolutions with those observed from MODIS. The potential impact of these results on tropical cyclone formation and intensity will be examined as well.

  12. Satellite Communications: The Indian Scenario

    Directory of Open Access Journals (Sweden)

    Dr. Ranjit Singh

    2014-05-01

    Full Text Available India has launched as many as 73 Indian satellites as of today since its first attempt in 1975. Besides serving traditional markets of telephony and broadcasting, satellites are on the frontiers of advanced applications as telemedicine, distance learning, environment monitoring, remote sensing, and so on. Satellite systems are optimized for services such as Internet access, virtual private networks and personal access. Costs have been coming down in recent years to the point where satellite broadband is becoming competitive. This article is an attempt to view this important topic from Indian perspective. India’s Project GAGAN, GPS Aided Geo Augmented Navigation is discussed.

  13. BeiDou inter-satellite-type bias evaluation and calibration for mixed receiver attitude determination

    NARCIS (Netherlands)

    Nadarajah, N.; Teunissen, P.J.G.; Raziq, N.

    2013-01-01

    The Chinese BeiDou system (BDS), having different types of satellites, is an important addition to the ever growing system of Global Navigation Satellite Systems (GNSS). It consists of Geostationary Earth Orbit (GEO) satellites, Inclined Geosynchronous Satellite Orbit (IGSO) satellites and Medium

  14. BeiDou inter-satellite-type bias evaluation and calibration for mixed receiver attitude determination

    NARCIS (Netherlands)

    Nadarajah, N.; Teunissen, P.J.G.; Raziq, N.

    2013-01-01

    The Chinese BeiDou system (BDS), having different types of satellites, is an important addition to the ever growing system of Global Navigation Satellite Systems (GNSS). It consists of Geostationary Earth Orbit (GEO) satellites, Inclined Geosynchronous Satellite Orbit (IGSO) satellites and Medium Ea

  15. Shadow imaging of geosynchronous satellites

    Science.gov (United States)

    Douglas, Dennis Michael

    Geosynchronous (GEO) satellites are essential for modern communication networks. If communication to a GEO satellite is lost and a malfunction occurs upon orbit insertion such as a solar panel not deploying there is no direct way to observe it from Earth. Due to the GEO orbit distance of ~36,000 km from Earth's surface, the Rayleigh criteria dictates that a 14 m telescope is required to conventionally image a satellite with spatial resolution down to 1 m using visible light. Furthermore, a telescope larger than 30 m is required under ideal conditions to obtain spatial resolution down to 0.4 m. This dissertation evaluates a method for obtaining high spatial resolution images of GEO satellites from an Earth based system by measuring the irradiance distribution on the ground resulting from the occultation of the satellite passing in front of a star. The representative size of a GEO satellite combined with the orbital distance results in the ground shadow being consistent with a Fresnel diffraction pattern when observed at visible wavelengths. A measurement of the ground shadow irradiance is used as an amplitude constraint in a Gerchberg-Saxton phase retrieval algorithm that produces a reconstruction of the satellite's 2D transmission function which is analogous to a reverse contrast image of the satellite. The advantage of shadow imaging is that a terrestrial based redundant set of linearly distributed inexpensive small telescopes, each coupled to high speed detectors, is a more effective resolved imaging system for GEO satellites than a very large telescope under ideal conditions. Modeling and simulation efforts indicate sub-meter spatial resolution can be readily achieved using collection apertures of less than 1 meter in diameter. A mathematical basis is established for the treatment of the physical phenomena involved in the shadow imaging process. This includes the source star brightness and angular extent, and the diffraction of starlight from the satellite

  16. Progress in developing GeoSTAR: a microwave sounder for GOES-R

    Science.gov (United States)

    Lambrigtsen, B. H.; Brown, S. T.; Dinardo, S. J.; Kangaslahti, P. P.; Tanner, A. B.; Wilson, W. J.

    2005-08-01

    The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) is a new concept for a microwave sounder, intended to be deployed on NOAA's next generation of geostationary weather satellites, GOES-R. A ground based prototype has been developed at the Jet Propulsion Laboratory, under NASA Instrument Incubator Program sponsorship, and is currently undergoing tests and performance characterization. The initial space version of GeoSTAR will have performance characteristics equal to those of the AMSU system currently operating on polar orbiting environmental satellites, but subsequent versions will significantly outperform AMSU. In addition to all-weather temperature and humidity soundings, GeoSTAR will also provide continuous rain mapping, tropospheric wind profiling and real time storm tracking. In particular, with the aperture synthesis approach used by GeoSTAR it is possible to achieve very high spatial resolutions without having to deploy the impractically large parabolic reflector antenna that is required with the conventional approach. GeoSTAR therefore offers both a feasible way of getting a microwave sounder in GEO as well as a clear upgrade path to meet future requirements. GeoSTAR offers a number of other advantages relative to real-aperture systems as well, such as 2D spatial coverage without mechanical scanning, system robustness and fault tolerance, operational flexibility, high quality beam formation, and open ended performance expandability. The technology and system design required for GeoSTAR are rapidly maturing, and it is expected that a space demonstration mission can be developed before the first GOES-R launch. GeoSTAR will be ready for operational deployment 2-3 years after that.

  17. GeoEn -Research on Geo-Energy

    Science.gov (United States)

    Liebscher, A.; Scheck-Wenderoth, M.; GeoEn Research Group

    2012-04-01

    Axel Liebscher1, Magdalena Scheck-Wenderoth1 and the GeoEn Research Group1, 2,3 1 Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany 2 University Potsdam, Germany 3 BTU Cottbus, Germany One of the pressing challenges for the 21st century is a secure, sustainable and economical energy supply at simultaneous mitigation of its climate impact. Besides a switch to renewable energy resources, the exploration and exploitation of new, unconventional energy resources will play a major role as will the further use of fossil fuels. With the switch to renewable energies the question of geological energy storage will become an important topic whereas further use of fossil fuels requires strategies like CCS to reduce its negative climate impacts. These different aspects of geo-energy make complementary or competitive demands on the subsurface and its use. It is therefore essential to treat the subsurface as a geo-resource of its own right. So far, geo-resource related research has often focused on specific resource systems, e.g. ore forming systems, hydrocarbon systems or geothermal systems, providing results largely applicable only to the restricted range of physicochemical properties of the respective geo-resource systems. However, with the increasing use of the subsurface as important geo-resource, the different geo-resource systems tend to overlap and interact and also become much more complex due to the additional use or presence of artificial and technical matter, as is the case in geological CO2 storage. On the other hand, the combined use of the subsurface for different purposes may also create synergetic effects. GeoEn is a joint research project explicitly addressing the fundamental questions related to the sustainable and holistic use of the geo-resource subsurface with a special focus on geo-energy. Project partners are the German Research Centre for Geosciences (GFZ), the University of Potsdam (UP) and the Brandenburg University of

  18. The Principle of Navigation Constellation Composed of SIGSO Communication Satellites

    CERN Document Server

    Ji, Hai-Fu; Ai, Guo-Xiang; Shi, Hu-Li

    2012-01-01

    The Chinese Area Positioning System (CAPS), a navigation system based on GEO communication satellites, was developed in 2002 by astronomers at Chinese Academy of Sciences. Extensive positioning experiments of CAPS have been performed since 2005. On the basis of CAPS, this paper studies the principle of navigation constellation composed of Slightly Inclined Geostationary Orbit (SIGSO) communication satellites. SIGSO satellites are derived from end-of-life Geostationary Orbit (GEO) satellites under inclined orbit operation. Considering the abundant frequency resources of SIGSO satellites, multi-frequency observations could be conducted to enhance the precision of pseudorange measurements and ameliorate the positioning performence. The constellation composed of two GEO satellites and four SIGSO satellites with inclination of 5 degrees can provide the most territory of China with 24-hour maximum PDOP less than 42. With synthetic utilization of the truncated precise (TP) code and physical augmentation factor in fo...

  19. China's Meteorological Satellite Application System

    Institute of Scientific and Technical Information of China (English)

    Zhang Jiashen

    2008-01-01

    @@ (Continued) Applications In Global Environment And Natural Disaster Monitoring 1) Application in world crop yield estimation China is now one of the few nations in the world that can provide operational service with both GEO and polar-orbit meteorological satellites.

  20. 热控涂层红外发射率对GEO卫星蓄电池温度波动的影响%Effect of Thermal Control Battery Temperature Coatings Infrared Emittance on Variation in GEO Satellite

    Institute of Scientific and Technical Information of China (English)

    刘百麟; 周佐新

    2012-01-01

    Based on DFH-3 satellite platform, the simplified south satellite battery cabin is presen- ted as the thermal analysis model. According to the mechanism of battery temperature variation, five combination schemes, in which the thermal control coatings of white paint,aluminized kapton and graphite-epoxy facesheet are used for inner panel of service module board, are proposed and used to analyze the effect of thermal control coatings infrared emittance on battery temperature. The analysis results show that the range of battery temperature variation can be reduced effectively by decreasing the thermal control coatings infrared emittance of inner panel in battery cabin, especially decreasing the thermal control coatings infrared emittance of fixing panel in battery cabin. The range of battery temperature variation in optimization scheme is decreased by 50% than that in original design scheme.%在东方红一3卫星平台的基础上,将合理简化后的南蓄电池舱作为热分析模型。根据影响蓄电池温度波动的机理,提出服务舱舱板内表面常用热控涂层(白漆、镀铝膜、碳蒙皮)的5种组合方案,并量化分析了热控涂层红外发射率对蓄电池温度波动的影响。分析结果表明:降低蓄电池舱舱板内表面热控涂层红外发射率,尤其是降低蓄电池安装舱板表面的热控涂层红外发射率,可有效减小蓄电池温度波动幅度。与基准方案相比,最优组合方案能使蓄电池温度波动幅度降低50%。

  1. Assessing DRAGON Measurements for Evaluation and Assimilation in the GEOS-5 Aerosol Forecasting System

    Science.gov (United States)

    da Silva, A.; Colarco, P. R.; Darmenov, A.; Holben, B. N.

    2013-12-01

    GEOS-5 is the latest version of the NASA Global Modeling and Assimilation Office (GMAO) earth system model. GEOS-5 contains components for atmospheric circulation and composition (including data assimilation), ocean circulation and biogeochemistry, and land surface processes. In addition to traditional meteorological parameters, GEOS-5 includes modules representing the atmospheric composition, most notably aerosols and tropospheric/stratospheric chemical constituents, taking explicit account of the impact of these constituents on the radiative processes of the atmosphere. The assimilation of Aerosol Optical Depth (AOD) in GEOS-5 involves very careful cloud screening and homogenization of the observing system by means of a Neural Net scheme that translates MODIS radiances into AERONET calibrated AOD. These measurements are further quality controlled using an adaptive buddy check scheme, and assimilated using the Local Displacement Ensemble (LDE) methodology. The near real-time GEOS-5 aerosol forecasting system runs at a nominal 25km horizontal resolution with 72 vertical layers (top at ~85km). GEOS-5 is driven by daily biomass burning emissions derived from MODIS fire radiative power retrievals. In this talk we will utilize aerosol measurements from the Distributed Regional Aerosol Gridded Observation Networks (DRAGON) to evaluate the temporal and spatial distribution of aerosols in GEOS-5. While NRT assimilation of MODIS optical depth observations constrains the GEOS-5 aerosol distributions during satellite overpasses, the diurnal cycle, mixing state and optical properties are internally determined by the model parameterizations and require careful validation. By combining DRAGON with other in-situ and remotely sensed measurements from the DISCOVER-AQ and SEAC4RS field campaigns we will present a comprehensive evaluation of the GEOS-5 aerosol state, and examine the impact of assimilating the DRAGON measurements on the quality of the GEOS-5 analysis and forecasts

  2. TNX GeoSiphon{trademark} Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Phifer, M.A.

    2001-07-10

    This report provides a summary of the TNX GeoSiphon Program results. The D-Area hydraulic results are utilized in conjunction with the TNX hydraulic results to provide a more complete interpretation of GeoSiphon hydraulics.

  3. GeoLab Sample Handling System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop  a robotic sample handling/ manipulator system for the GeoLab glovebox. This work leverages from earlier GeoLab work and a 2012 collaboration with a...

  4. A Mapping Approach for Large Area Wind Farm Based on Geoeye-1 Satellite Stereo Images%基于GeoEye-1立体像对的风电场大范围地形测量方法

    Institute of Scientific and Technical Information of China (English)

    张雅楠; 宋志勇

    2013-01-01

    Based on Geoeye-1 satellite stereo images,the mapping works for a wind farm which covers 200 square kilometers area in Huan County,Gansu province have been completed in this paper.A new fast and efficient way is provided for the large area surveying of wind power project.Compared with traditional methods,the new mapping approach would satisfy the demand of wind power projects for the tight schedule and large area.The mapping accuracy of this method is between 1∶2000 scale and 1:5000 scale.Meanwhile,high resolution DOM and high precision DEM can also be provided for the wind farm design.The digital productions can meet the demands of design changing and reduce the engineering cost.%基于Geoeye-1卫星影像立体像对完成了甘肃环县地区某风电场约200km2的测图工作,为风力发电项目大范围地形测量提供了一种新的快速高效的作业模式.相较于传统测量方法,该作业模式能够更好地满足风力发电项目测图范围大、设计工期紧的需求,成图精度介于1∶2000比例尺测图及1∶5000比例尺测图之间,并可提供高分辨率的DOM及高精度的DEM产品,更好地辅助风电场设计.其提供的大范围地形,可极大程度地满足设计变更的需要,降低工程成本.

  5. Geo-Enabled, Mobile Services

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard

    2006-01-01

    We are witnessing the emergence of a global infrastructure that enables the widespread deployment of geo-enabled, mobile services in practice. At the same time, the research community has also paid increasing attention to data management aspects of mobile services. This paper offers me an opportu...

  6. Geo-Enabled, Mobile Services

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard

    2006-01-01

    We are witnessing the emergence of a global infrastructure that enables the widespread deployment of geo-enabled, mobile services in practice. At the same time, the research community has also paid increasing attention to data management aspects of mobile services. This paper offers me...

  7. Nitrogen dioxide observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument: Retrieval algorithm and measurements during DISCOVER-AQ Texas 2013

    Science.gov (United States)

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA F...

  8. Nitrogen dioxide observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument: Retrieval algorithm and measurements during DISCOVER-AQ Texas 2013

    Science.gov (United States)

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA F...

  9. GeoGebra for Mathematical Statistics

    Science.gov (United States)

    Hewson, Paul

    2009-01-01

    The GeoGebra software is attracting a lot of interest in the mathematical community, consequently there is a wide range of experience and resources to help use this application. This article briefly outlines how GeoGebra will be of great value in statistical education. The release of GeoGebra is an excellent example of the power of free software…

  10. GEO vs. LEO Space Telecommunication Systems Commercial Set Up, Finance &Economics

    Science.gov (United States)

    Kreisel, Joerg

    2002-01-01

    Space-based commercial telecommunication systems - especially in GEO - still represent the big volume segment in commercial space and probably will do so for a while. Although such end-to-end systems both in GEO and LEO are using satellites, ground stations, and service centers, etc., their commercial genesis differs significantly. Based on existing and planned space telecommunication businesses, this paper deals with prime characteristics of commercial GEO and LEO systems and their differences. In a tutorial way the stages of development of both LEO- and GEO-type business ventures are presented. The entire commercial development path is covered (concept, business plan, financing, partnership, growth, etc.). Focus is to understand what drives space telecommunication business and what it takes to start such new commercial space ventures. The perspective given is also based on the author's longstanding background in space commercialization and experiences made as a venture capitalist.

  11. Femto-satellite Swarm State and Density Estimation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is planning future missions involving fleets of small satellites in LEO and GEO that can exhibit autonomous collective behavior. Such a "swarm of...

  12. NEPR World View 2 Satellite Mosaic - NOAA TIFF Image

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This GeoTiff is a mosaic of World View 2 panchromatic satellite imagery of Northeast Puerto Rico that contains the shallow water area (0-35m deep) surrounding...

  13. Integrated GNSS attitude determination and positioning for direct geo-referencing

    NARCIS (Netherlands)

    Nadarajah, N.; Paffenholz, J.A.; Teunissen, P.J.G.

    2014-01-01

    Direct geo-referencing is an efficient methodology for the fast acquisition of 3D spatial data. It requires the fusion of spatial data acquisition sensors with navigation sensors, such as Global Navigation Satellite System (GNSS) receivers. In this contribution, we consider an integrated GNSS naviga

  14. Satellite communications network design and analysis

    CERN Document Server

    Jo, Kenneth Y

    2011-01-01

    This authoritative book provides a thorough understanding of the fundamental concepts of satellite communications (SATCOM) network design and performance assessments. You find discussions on a wide class of SATCOM networks using satellites as core components, as well as coverage key applications in the field. This in-depth resource presents a broad range of critical topics, from geosynchronous Earth orbiting (GEO) satellites and direct broadcast satellite systems, to low Earth orbiting (LEO) satellites, radio standards and protocols.This invaluable reference explains the many specific uses of

  15. Robust Geo-neutrino Results

    CERN Document Server

    Dye, Steve

    2016-01-01

    Geo-neutrino observations probe the quantities and distributions of terrestrial heat-producing elements uranium and thorium. The quantities of these elements gauge global radiogenic power, offering insights into the origin and thermal history of the Earth. The distributions reveal the initial partitioning and subsequent transport of these trace elements between metallic core, silicate mantle, and crust types. Ongoing observations at underground sites in Japan and Italy record the energies but not the directions of geo-neutrinos from uranium and thorium. Without directions pointing back to source regions, disentangling the signals from various reservoirs requires resolution of differing rates or energy spectra at separate sites. Due to limited statistics and site contrast, however, the observations at Japan and Italy do not yet measure distinct rates or energy spectra. Further analyses of the observations that derive fluxes, determine a signal from the mantle, and assess the global radiogenic power of uranium ...

  16. Stereoscopic observations from meteorological satellites

    Science.gov (United States)

    Hasler, A. F.; Mack, R.; Negri, A.

    The capability of making stereoscopic observations of clouds from meteorological satellites is a new basic analysis tool with a broad spectrum of applications. Stereoscopic observations from satellites were first made using the early vidicon tube weather satellites (e.g., Ondrejka and Conover [1]). However, the only high quality meteorological stereoscopy from low orbit has been done from Apollo and Skylab, (e.g., Shenk et al. [2] and Black [3], [4]). Stereoscopy from geosynchronous satellites was proposed by Shenk [5] and Bristor and Pichel [6] in 1974 which allowed Minzner et al. [7] to demonstrate the first quantitative cloud height analysis. In 1978 Bryson [8] and desJardins [9] independently developed digital processing techniques to remap stereo images which made possible precision height measurement and spectacular display of stereograms (Hasler et al. [10], and Hasler [11]). In 1980 the Japanese Geosynchronous Satellite (GMS) and the U.S. GOES-West satellite were synchronized to obtain stereo over the central Pacific as described by Fujita and Dodge [12] and in this paper. Recently the authors have remapped images from a Low Earth Orbiter (LEO) to the coordinate system of a Geosynchronous Earth Orbiter (GEO) and obtained stereoscopic cloud height measurements which promise to have quality comparable to previous all GEO stereo. It has also been determined that the north-south imaging scan rate of some GEOs can be slowed or reversed. Therefore the feasibility of obtaining stereoscopic observations world wide from combinations of operational GEO and LEO satellites has been demonstrated. Stereoscopy from satellites has many advantages over infrared techniques for the observation of cloud structure because it depends only on basic geometric relationships. Digital remapping of GEO and LEO satellite images is imperative for precision stereo height measurement and high quality displays because of the curvature of the earth and the large angular separation of the

  17. The State of the GeoWall

    Science.gov (United States)

    Morin, P. J.; Leigh, J.; van Keken, P.; Johnson, A.

    2003-12-01

    The GeoWall stereo projection technology has been widely adopted within Earth Science. Over 20,000 undergraduate students per year use a GeoWall in classroom and lab settings at over 80 institutions around the world using over 200 GeoWalls. We believe that critical mass for this technology has been reached in the Earth Science. Many collaborations have been initiated. With Iris, GeoWall is exploring new ways to monitor seismic networks in real-time and to visualize extremely large, whole Earth seismic simulations. We are also working with a number of drilling organizations including JOI, DOSECC and LacCore to bring modern visualization technology to core interpretation and drill site selection. Also, over 15 museums now have or are building GeoWalls for informal education. Much of the science that is being performed on the GeoWall is finding its way directly into the classroom and science museum. One of the success stories has been the GeoWall Consortium's interaction with industry. The basic hardware for the GeoWall has been spun off to companies that now sell variations of the hardware. In addition, many software companies including ESRI and Dynamic Graphics have added support for the GeoWall in their products. The future of GeoWall is four fold. Curriculum development will bring more material to all GeoWall users. Assessment of the curriculum and educational psychology will give us GeoWall best practices. In technology development, the GeoWall 2 is a 20+ million pixel, tiled display which brings more resolution to the Earth Sciences than ever. To support research the consortium is developing a volume rendering application to visualize extremely large datasets.

  18. Analysis of the Bias on the Beidou GEO Multipath Combinations

    Directory of Open Access Journals (Sweden)

    Yafei Ning

    2016-08-01

    Full Text Available The Beidou navigation satellite system is a very important sensor for positioning in the Asia-Pacific region. The Beidou inclined geosynchronous orbit (IGSO and medium Earth orbit (MEO satellites have been analysed in some studies previously conducted by other researchers; this paper seeks to gain more insight regarding the geostationary earth orbit (GEO satellites. Employing correlation analysis, Fourier transformation and wavelet decomposition, we validate whether there is a systematic bias in their multipath combinations. These biases can be observed clearly in satellites C01, C02 and C04 and have a great correlation with time series instead of elevation, being significantly different from those of the Beidou IGSO and MEO satellites. We propose a correction model to mitigate this bias based on its daily periodicity characteristic. After the model has been applied, the performance of the positioning estimations of the eight stations distributed in the Asia-Pacific region is evaluated and compared. The results show that residuals of multipath series behaves random noise; for the single point positioning (SPP and precise point positioning (PPP approaches, the positioning accuracy in the upward direction can be improved by 8 cm and 6 mm, respectively, and by 2 cm and 4 mm, respectively, for the horizontal component.

  19. Analysis of the Bias on the Beidou GEO Multipath Combinations

    Science.gov (United States)

    Ning, Yafei; Yuan, Yunbin; Chai, Yanju; Huang, Yong

    2016-01-01

    The Beidou navigation satellite system is a very important sensor for positioning in the Asia-Pacific region. The Beidou inclined geosynchronous orbit (IGSO) and medium Earth orbit (MEO) satellites have been analysed in some studies previously conducted by other researchers; this paper seeks to gain more insight regarding the geostationary earth orbit (GEO) satellites. Employing correlation analysis, Fourier transformation and wavelet decomposition, we validate whether there is a systematic bias in their multipath combinations. These biases can be observed clearly in satellites C01, C02 and C04 and have a great correlation with time series instead of elevation, being significantly different from those of the Beidou IGSO and MEO satellites. We propose a correction model to mitigate this bias based on its daily periodicity characteristic. After the model has been applied, the performance of the positioning estimations of the eight stations distributed in the Asia-Pacific region is evaluated and compared. The results show that residuals of multipath series behaves random noise; for the single point positioning (SPP) and precise point positioning (PPP) approaches, the positioning accuracy in the upward direction can be improved by 8 cm and 6 mm, respectively, and by 2 cm and 4 mm, respectively, for the horizontal component. PMID:27509503

  20. SOIL Geo-Wiki: A tool for improving soil information

    Science.gov (United States)

    Skalský, Rastislav; Balkovic, Juraj; Fritz, Steffen; See, Linda; van der Velde, Marijn; Obersteiner, Michael

    2014-05-01

    Crowdsourcing is increasingly being used as a way of collecting data for scientific research, e.g. species identification, classification of galaxies and unravelling of protein structures. The WorldSoilProfiles.org database at ISRIC is a global collection of soil profiles, which have been 'crowdsourced' from experts. This system, however, requires contributors to have a priori knowledge about soils. Yet many soil parameters can be observed in the field without specific knowledge or equipment such as stone content, soil depth or color. By crowdsourcing this information over thousands of locations, the uncertainty in current soil datasets could be radically reduced, particularly in areas currently without information or where multiple interpretations are possible from different existing soil maps. Improved information on soils could benefit many research fields and applications. Better soil data could enhance assessments of soil ecosystem services (e.g. soil carbon storage) and facilitate improved process-based ecosystem modeling from local to global scales. Geo-Wiki is a crowdsourcing tool that was developed at IIASA for land cover validation using satellite imagery. Several branches are now available focused on specific aspects of land cover validation, e.g. validating cropland extent or urbanized areas. Geo-Wiki Pictures is a smart phone application for collecting land cover related information on the ground. The extension of Geo-Wiki to a mobile environment provides a tool for experts in land cover validation but is also a way of reaching the general public in the validation of land cover. Here we propose a Soil Geo-Wiki tool that builds on the existing functionality of the Geo-Wiki application, which will be largely designed for the collection and sharing of soil information. Two distinct applications are envisaged: an expert-oriented application mainly for scientific purposes, which will use soil science related language (e.g. WRB or any other global reference

  1. BDS relative static positioning over long baseline improved by GEO multipath mitigation

    Science.gov (United States)

    Wang, Min; Chai, Hongzhou; Liu, Jun; Zeng, Anmin

    2016-02-01

    Due to the satellite and constellation deployment design, the variation pattern of multipath effect in BeiDou Navigation Satellite System (BDS) code observation is different from GPS. The amplitude of systematic multipath variation (SMV) exists in multipath combination series may exceed 0.5 m for some geostationary earth orbit (GEO) satellites, which is larger than the normal noise level of GPS code observation. After characterization of the variation pattern of BDS multipath series for BDS GEO satellites, we propose to improve the performance of relative positioning over long baseline by mitigating the SMV effect of GEO satellite. The proposed method uses the SMV extracted from multipath (MP) combination series with adaptive wavelet transform as correction for current day observation in post-processing use or as following day correction in real-time use. In addition, the Double Station Observation Processing (DSOP) method that directly uses undifferenced observation is applied for relative static positioning. Experiment results show improvement in convergence speed for both BDS only and BDS/GPS combined solution.

  2. Optimal GEO lasercomm terminal field of view for LEO link support

    Science.gov (United States)

    Hindman, Charles W.; Hunt, Jeffrey P.; Engberg, Brian S.; Walchko, Kevin J.

    2006-02-01

    As alternatives to the traditional gimbaled terminal design, future satellite based laser communications terminals are envisioned that utilize a wide field of view or field of regard (WFOV/WFOR). This approach can be advantageous in situations requiring rapid switching between user terminals, support for multiple terminals simultaneously (via TDMA, SDMA or WDMA) or other non-standard mission requirements. However, a traditional gimbaled terminal has the capability to continuously track a single user over very large angles, such as the 18-20° spanned by a LEO satellite as seen from GEO. WFOV/WFOR designs face increasing cost and/or complexity issues with each incremental increase in angular coverage. The methodology and inputs for a trade study are presented here that attempts to maximize the available connectivity to a LEO satellite while minimizing cost and complexity metrics by choosing an optimal FOV/FOR size for a GEO terminal.

  3. Detailed gravity anomalies from GEOS-3 satellite altimetry data

    Science.gov (United States)

    Gopalapillai, G. S.; Mourad, A. G.

    1978-01-01

    A technique for deriving mean gravity anomalies from dense altimetry data was developed. A combination of both deterministic and statistical techniques was used. The basic mathematical model was based on the Stokes' equation which describes the analytical relationship between mean gravity anomalies and geoid undulations at a point; this undulation is a linear function of the altimetry data at that point. The overdetermined problem resulting from the excessive altimetry data available was solved using Least-Squares principles. These principles enable the simultaneous estimation of the associated standard deviations reflecting the internal consistency based on the accuracy estimates provided for the altimetry data as well as for the terrestrial anomaly data. Several test computations were made of the anomalies and their accuracy estimates using GOES-3 data.

  4. Using Optical Interferometry for GEO Satellites Imaging: An Update

    Science.gov (United States)

    2016-05-27

    James H. Clark IIIa aRemote Sensing Division, Naval Research Laboratory, Washington, DC20375, USA ; ABSTRACT We describe multi-baseline observations...baselines, Invited Paper Micro- and Nanotechnology Sensors, Systems, and Applications VIII, edited by Thomas George, Achyut K. Dutta, M. Saif Islam

  5. Optical Survey of the Tumble Rates of Retired GEO Satellites

    Science.gov (United States)

    2014-09-01

    the rendezvous and docking phase of the mission, which influences the rate of propellant utilization for the Servicer/Tender. In order to provide a...in an intentional spin state about its major spin axis (as with TDRS -1[4]), there are several natural effects that influence the rotational motion of...the CCD in order to characterize the noise across the sensor. After this, collections begin—session length ranges from 15 minutes to several hours

  6. GEOS-3 ocean geoid investigation

    Science.gov (United States)

    Yionoulis, S. M.; Eisner, A.; Pisacane, V. L.; Black, H. D.; Pryor, L. L.

    1978-01-01

    A determination of the fine scale sea surface topography in the GEOS-3 calibration area using the radar altimeter data is presented. Estimates of the north-south and east-west components of the deflections of the vertical as well as values of the geoidal heights were made. Three major stages of processing were used in obtaining the final results. The first two use pass processors; in the final stage, the processor combines all the pass results to compute the final results. The results obtained compare favorably with gravimetrically determined geoids for this calibration area.

  7. Gravimetric geodesy and sea surface topography studies by means of satellite-to-satellite tracking and satellite altimetry

    Science.gov (United States)

    Siry, J. W.

    1972-01-01

    A satellite-to-satellite tracking experiment is planned between ATS-F and GEOS-C with a range accuracy of 2-meters and a range rate accuracy of 0.035 centimeters per second for a 10-second integration time. This experiment is planned for 1974. It is anticipated that it will improve the spatial resolution of the satellite geoid by half an order of magnitude to about 6 degrees. Longer integration times should also permit a modest increase in the acceleration resolution. Satellite altimeter data will also be obtained by means of GEOS-C. An overall accuracy of 5-meters in altitude is the goal. The altimeter, per se, is expected to have an instrumental precision of about 2 meters, and an additional capability to observe with a precision of about 0.2 meters for limited periods.

  8. Design and analysis of the satellite laser communications network

    Science.gov (United States)

    Ren, Pei-an; Qian, Fengchen; Liu, Qiang; Jin, Linlin

    2015-02-01

    A satellite laser communications network structure with two layers and multiple domains has been proposed, which performance has been simulated by OPENT. To simulation, we design several OPNET models of the network's components based on a satellite constellation with two layers and multiple domains, as network model, node model, MAC layer protocol and optical antenna model. The network model consists of core layer and access layer. The core network consists of four geostationary orbit (GEO) satellites which are uniformly distributed in the geostationary orbit. The access network consists of 6 low Earth orbit (LEO) satellites which is the walker delta (walk-δ) constellation with three orbit planes. In access layer, each plane has two satellites, and the constellation is stably. The satellite constellation presented for space laser network can meet the demand of coverage in the middle and low latitude by a few satellites. Also several terminal device models such as the space laser transmitter, receiver, protocol layer module and optical antenna have been designed according to the inter-satellite links in different orbits t from GEO to LEO or GEO to ground. The influence to network of different transmitting throughput, receiving throughput, network protocol and average time delay are simulated. Simulation results of network coverage, connectivity and traffic load performance in different scenes show that the satellite laser network presented by the paper can be fit for high-speed satellite communications. Such analysis can provide effective reference for the research of satellite laser networking and communication protocol.

  9. Space Domain Awareness for Manned GEO Servicing

    Science.gov (United States)

    Blake, T.

    2010-09-01

    The Defense Advanced Research Projects Agency (DARPA) is embarking on a joint program to service spacecraft in Geosynchronous (GEO) Orbit. This ambitious program, known as R5 (Rendezvous, Refuel, Refurbish, Repair, and Reposition), will develop the technologies required to extend the life of billions of dollars of invested in building, launching and operating GEO spacecraft. Inherent in the R5 program, is the need for high quality awareness of the space domain at GEO. Servicing non-operational spacecraft in GEO will require enhanced debris detect/track and space weather monitoring for crew safety, as well as high resolution characterization of the spacecraft to understand the status of the spacecraft to manifest the repair mission. This paper will briefly describe the GEO space domain sensor and data processing requirements to support the R5 program and outline DARPA’s program plans to develop these capabilities. Distribution Statement A (Approved for Public Release, Distribution Unlimited). DISTAR case 15410.

  10. GEOS-5 Chemistry Transport Model User's Guide

    Science.gov (United States)

    Kouatchou, J.; Molod, A.; Nielsen, J. E.; Auer, B.; Putman, W.; Clune, T.

    2015-01-01

    The Goddard Earth Observing System version 5 (GEOS-5) General Circulation Model (GCM) makes use of the Earth System Modeling Framework (ESMF) to enable model configurations with many functions. One of the options of the GEOS-5 GCM is the GEOS-5 Chemistry Transport Model (GEOS-5 CTM), which is an offline simulation of chemistry and constituent transport driven by a specified meteorology and other model output fields. This document describes the basic components of the GEOS-5 CTM, and is a user's guide on to how to obtain and run simulations on the NCCS Discover platform. In addition, we provide information on how to change the model configuration input files to meet users' needs.

  11. Final Technical Report -- GEO-VI - USGEO

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, Leonard

    2009-11-30

    Representatives of US earth observations departments and agencies, other participating governments, NGOs and civil society participated in the Sixth Plenary Meeting of the Group on Earth Observations (GEO-VI), hosted by the United States in Washington, DC on November 17 and 18, 2009. The meeting was held in the Atrium Ballroom of the Ronald Reagan International Trade Center. Exhibitions of international Earth observation technology and programs were held concurrently in the same venue. A number of GEO committee meetings and side events were held in conjunction with the GEO-VI Plenary, including the GEO-IGOS Symposium on Earth observation science and applications, the GEOSS in the Americas Forum on Coastal Zones, and separate meetings of the GEO Communities of Practice on Carbon, Health, and Air Quality.

  12. Geostationary Coastal and Air Pollution Events (GeoCAPE) Wide Angle Spectrometer (WAS)

    Science.gov (United States)

    Kotecki, Carl; Chu, Martha; Mannino, Antonio; Marx, Catherine Trout; Bowers, Gregory A.; Bolognese, Jeffrey A.; Matson, Elizabeth A.; McBirney, Thomas R.; Earle, Cleland P.; Choi, Michael K.; Stoneking, Eric; Luu, Kequan; Monosmith, William B.; Secunda, Mark S.; Brall, Aron; Samuels, Cabin

    2014-01-01

    The GeoCAPE Wide Angle Spectrometer (WAS) Study was a revisit of the COEDI Study from 2012. The customer primary goals were to keep mass, volume and cost to a minimum while meeting the science objectives and maximizing flight opportunities by fitting on the largest number of GEO accommodations possible. Riding on a commercial GEO satellite minimizes total mission costs. For this study, it is desired to increase the coverage rate,km2min, while maintaining ground sample size, 375m, and spectral resolution, 0.4-0.5nm native resolution. To be able to do this, the IFOV was significantly increased, hence the wide angle moniker. The field of view for COEDI was +0.6 degrees or (2048) 375m ground pixels. The WAS Threshold (the IDL study baseline design) is +2.4 degrees IDL study baseline design) is +2.4 degrees.

  13. ASDAR (aircraft to satellite data relay) flight test report

    Science.gov (United States)

    Domino, E. J.; Lovell, R. R.; Conroy, M. J.; Culp, D. H.

    1977-01-01

    The aircraft to Satellite Data Relay (ASDAR), an airborne data collection system that gathers meteorological data from existing aircraft instrumentation and relays it to ground user via a geo-synchronous meteorological satellite, is described and the results of the first test flight on a commercial Boeing 747 aircraft are presented. The flight test was successful and verified system performance in the anticipated environment.

  14. Astrometry and Geostationary Satellites in Venezuela

    Science.gov (United States)

    Lacruz, E.; Abad, C.

    2015-10-01

    We present the current status and the first results of the astrometric project CIDA - ABAE for tracking geo-stationary satellites. This project aims to determine a preliminary orbit for the Venezuelan satellite VENESAT-1, using astrometric positions obtained from an optical telescope. The results presented here are based on observations from the Luepa space tracking ground station in Venezuela, which were processed using astrometric procedures.

  15. Trends in mobile satellite communication

    Science.gov (United States)

    Johannsen, Klaus G.; Bowles, Mike W.; Milliken, Samuel; Cherrette, Alan R.; Busche, Gregory C.

    1993-01-01

    Ever since the U.S. Federal Communication Commission opened the discussion on spectrum usage for personal handheld communication, the community of satellite manufacturers has been searching for an economically viable and technically feasible satellite mobile communication system. Hughes Aircraft Company and others have joined in providing proposals for such systems, ranging from low to medium to geosynchronous orbits. These proposals make it clear that the trend in mobile satellite communication is toward more sophisticated satellites with a large number of spot beams and onboard processing, providing worldwide interconnectivity. Recent Hughes studies indicate that from a cost standpoint the geosynchronous satellite (GEOS) is most economical, followed by the medium earth orbit satellite (MEOS) and then by the low earth orbit satellite (LEOS). From a system performance standpoint, this evaluation may be in reverse order, depending on how the public will react to speech delay and collision. This paper discusses the trends and various mobile satellite constellations in satellite communication under investigation. It considers the effect of orbital altitude and modulation/multiple access on the link and spacecraft design.

  16. Geo-effectiveness of CMEs

    Indian Academy of Sciences (India)

    Ajaysinh K. Jadeja; K. N. Iyer; Hari Om Vats; P. K. Manoharan

    2008-03-01

    Coronal Mass Ejections (CMEs) are important phenomena in coronal dynamics causing interplanetary signatures (ICMEs). They eject large amounts of mass and magnetic fields into the heliosphere, causing major geomagnetic storms and interplanetary shocks. Geomagnetic storms are often characterized by abrupt increases in the northward component of the earth’s field, called sudden commencements (SSC) followed by large decreases of the magnetic field and slow recovery to normal values. The SSCs are well correlated with IP shocks. Here a case study of 10–15 February 2000 and also the statistical study of CME events observed by IPS array, Rajkot, during the years 2000 to 2003 and Radio Astronomy Center, Ooty are described. The geomagnetic storm index Dst, which is a measure of geo-effectiveness, is shown to be well correlated with normalized scintillation index `g', derived from Ooty Radio Telescope (ORT) observations.

  17. GEOS 3 ocean geoid investigation

    Science.gov (United States)

    Yionoulis, S. M.; Eisner, A.; Pisacane, V. L.; Black, H. D.; Pryor, L. L.

    1979-01-01

    A determination of the fine-scale sea surface topography in the GEOS 3 calibration area using the radar altimeter data is presented. Estimates of the north-south and east-west components of the deflections of the vertical as well as values of the geoidal heights are made. Three major stages of processing are used in obtaining the final results. The first two use pass processors; in the final stage the processor combines all the pass results to compute the final results. Comparison with a gravimetrically determined geoid for the calibration area, provided by the National Aeronautics and Space Administration, yielded a mean and standard deviation of 0.45 and 1.5 m, respectively

  18. Geostationary Coastal Ecosystem Dynamics Imager (GEO CEDI) for the GEO Coastal and Air Pollution Events (GEO CAPE) Mission. Concept Presentation

    Science.gov (United States)

    Janz, Scott; Smith, James C.; Mannino, Antonio

    2010-01-01

    This slide presentation reviews the concepts of the Geostationary Coastal Ecosystem Dynamics Imager (GEO CEDI) which will be used on the GEO Coastal and Air Pollution Events (GEO CAPE) Mission. The primary science requirements require scans of the U.S. Coastal waters 3 times per day during the daylight hours. Included in the overview are presentations about the systems, the optics, the detectors, the mechanical systems, the electromechanical systems, the electrical design, the flight software, the thermal systems, and the contamination prevention requirements.

  19. Geography Geo-Wiki in the Classroom: Using Crowdsourcing to Enhance Geographical Teaching

    Directory of Open Access Journals (Sweden)

    Christoph Perger

    2014-09-01

    Full Text Available Geo-Wiki is a crowdsourcing tool used to derive information, based on satellite imagery, to validate and enhance global land cover. Around 5000 users are registered, who contribute to different campaigns to collect data across various domains (e.g., agriculture, biomass, human impact, etc.. However, seeing the Earth’s surface from above does not provide all of the necessary information for understanding what is happening on the ground. Instead, we need to enhance this experience with local knowledge or with additional information, such as geo-located photographs of surface features with annotation. The latest development in enhancing Geo-Wiki in this context has been achieved through collaboration with the University of Waterloo to set up a separate branch called Geography Geo-Wiki for use in undergraduate teaching. We provide the pedagogical objectives for this branch and describe two modules that we have introduced in first and third year Physical Geography classes. The majority of the feedback was positive and in, many cases, was part of what the student liked best about the course. Future plans include the development of additional assignments for the study of environmental processes using Geo-Wiki that would engage students in a manner that is very different from that of conventional teaching.

  20. GEO NAV/CNAV-type Broadcast Ephemeris Fitting without Rotation of Inclination

    Directory of Open Access Journals (Sweden)

    DU Lan

    2017-03-01

    Full Text Available The GPS-type broadcast ephemerides are currently used by BDS constellation. However, a 5°-rotation added on the original orbital inclination is needed in the GEOs ephemeris parameters fitting algorithm as well as in the user satellite position computation because of the singularity due to small inclination. Besides, the phenomena of exceeding the given boundary happen occasionally for some ephemeris parameters of GEOs. In order to unify the user ephemerides algorithm for the hybrid constellation, a two-step GEO broadcast ephemerides fitting algorithm was analyzed based on the first class nonsingular orbital elements. After the investigation on the reason for the variations of some ephemeris parameters out of limited range, a reduced fitting parameter set was adopted by giving the underlying one or two parameters with fixed values. Fit simulations for 5 GEOs during both eclipsing and non-eclipsing periods show that the two-step fitting algorithm has considerable robustness to ensure the success rate and fitting accuracy. The mean fitting user range error of GEOs with 2 h for NAV and 3 h data set for CNAV are better than 3 mm. For specific fit arcs with the boundary-exceeding problem, it can be fully avoided by using the fitting algorithm with a reduced fitting parameter set. However, the fitting URE will increase to 2 cm.

  1. Extreme value problems of the convergence of a satellite and an observer

    Science.gov (United States)

    Zhagar, Iu. Kh.; Zarinsh, A. Ia.

    Equations are presented for five different cases of the convergence of a satellite and an observer. An exact definition is proposed for the culmination of a satellite, and its relation to other convergence points is examined. A proof is presented for four theorems on the properties of convergence points, and computations are carried out for the GEOS-A satellite to illustrate the theorems.

  2. Neutrino Mixing Discriminates Geo-reactor Models

    CERN Document Server

    Dye, S T

    2009-01-01

    Geo-reactor models suggest the existence of natural nuclear reactors at different deep-earth locations with loosely defined output power. Reactor fission products undergo beta decay with the emission of electron antineutrinos, which routinely escape the earth. Neutrino mixing distorts the energy spectrum of the electron antineutrinos. Characteristics of the distorted spectrum observed at the earth's surface could specify the location of a geo-reactor, discriminating the models and facilitating more precise power measurement. The existence of a geo-reactor with known position could enable a precision measurement of the neutrino oscillation parameter delta-mass-squared.

  3. Determination of the position of the Station Borowiec No. 7811 by satellite laser observations.

    Science.gov (United States)

    Dobaczewská, W.; Drozyner, A.; Rutkowska, M.; Schillak, S.; Zieliňski, J. B.

    Laser observations were performed in Borowiec in three years 1977 - 79 of the satellites Geos A and Geos C. These data were processed by means of the program ORBITA and station coordinates were calculated by dynamical methods. Another solution was found with the processing by the program GRIPE of SAO. These two dynamical solutions are compared with the translocation solution Wettzel-Borowiec.

  4. Satellite Communication.

    Science.gov (United States)

    Technology Teacher, 1985

    1985-01-01

    Presents a discussion of communication satellites: explains the principles of satellite communication, describes examples of how governments and industries are currently applying communication satellites, analyzes issues confronting satellite communication, links mathematics and science to the study of satellite communication, and applies…

  5. Using Sketches and Knowledge Bases for Geo-Spatial Image Retrieval

    OpenAIRE

    Bertolotto, Michela; Carswell, James; McLoughlin, E.; O Sullivan, D.; Wilson, C

    2006-01-01

    This paper presents research in the field of knowledge management for geo-spatial imagery including scanned aerial photos and satellite images. We have developed a web-based system that allows users to query a database of images not only using metadata, but also drawing sketches of configurations of objects they are interested in as well as inputting textual descriptions of their intended task. Our system integrates case-based reasoning techniques to form a knowledge base from previously issu...

  6. Northeast Puerto Rico and Culebra Island World View 2 Satellite Mosaic - NOAA TIFF Image

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This GeoTiff is a mosaic of World View 2 panchromatic satellite imagery of Northeast Puerto Rico that contains the shallow water area (0-35m deep) surrounding...

  7. West Bank Gaza Geo-MIS System

    Data.gov (United States)

    US Agency for International Development — The Geo-MIS System is USAID/West Bank and Gaza's primary system for capturing and managing projectrelated information. Its purpose is to assist USAID and its...

  8. GeoPlace v. 1.0

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-02

    GeoPlace software solves several problems related to efficient sensor placement for remote sensing. It consists of several components. “GeoFoot” finds efficient locations for centering a set of camera images, in order to ensure that the collection of images contains an entire region. It is built on a modified version of “Simple MPS”. GeoSubFoot selects non-overlapping rectangular subregions of a single camera image, in order to devote more resources for higher-fidelity sub-images of those regions. The goal is for the rectangular subregions to contain many user-specified pixels of interest. Simple MPS is a generic program that produces point-sample distributions with blue noise characteristics over arbitrary-dimensional squares. GeoFoot includes an extension of it to sampling from polygons in 2d, including both the inside of the polygon and slightly outside it.

  9. EnerGEO biomass pilot

    Energy Technology Data Exchange (ETDEWEB)

    Tum, M.; Guenther, K.P. [German Aerospace Center (DLR), Wessling (Germany). German Remote Sensing Data Center (DFD); McCallum, I.; Balkovic, J.; Khabarov, N.; Kindermann, G.; Leduc, S. [International Institute for Applied Systems Analysis (IIASA), Laxenburg (Austria); Biberacher, M. [Research Studios Austria AG (RSA), Salzburg (Austria)

    2013-07-01

    In the framework of the EU FP7 project EnerGEO (Earth Observations for Monitoring and Assessment of the Environmental Impact of Energy Use) sustainable energy potentials for forest and agricultural areas were estimated by applying three different model approaches. Firstly, the Biosphere Energy Transfer Hydrology (BETHY/DLR) model was applied to assess agricultural and forest biomass increases on a regional scale with the extension to grassland. Secondly, the EPIC (Environmental Policy Integrated Climate) - a cropping systems simulation model - was used to estimate grain yields on a global scale and thirdly the Global Forest Model (G4M) was used to estimate global woody biomass harvests and stock. The general objective of the biomass pilot is to implement the observational capacity for using biomass as an important current and future energy resource. The scope of this work was to generate biomass energy potentials for locations on the globe and to validate these data. Therefore, the biomass pilot was focused to use historical and actual remote sensing data as input data for the models. For validation purposes, forest biomass maps for 1987 and 2002 for Germany (Bundeswaldinventur (BWI-2)) and 2001 and 2008 for Austria (Austrian Forest Inventory (AFI)) were prepared as reference. (orig.)

  10. The GEOS-iODAS: Description and Evaluation

    Science.gov (United States)

    Vernieres, Guillaume; Rienecker, Michele M.; Kovach, Robin; Keppenne, Christian L.

    2012-01-01

    This report documents the GMAO's Goddard Earth Observing System sea ice and ocean data assimilation systems (GEOS iODAS) and their evolution from the first reanalysis test, through the implementation that was used to initialize the GMAO decadal forecasts, and to the current system that is used to initialize the GMAO seasonal forecasts. The iODAS assimilates a wide range of observations into the ocean and sea ice components: in-situ temperature and salinity profiles, sea level anomalies from satellite altimetry, analyzed SST, and sea-ice concentration. The climatological sea surface salinity is used to constrain the surface salinity prior to the Argo years. Climatological temperature and salinity gridded data sets from the 2009 version of the World Ocean Atlas (WOA09) are used to help constrain the analysis in data sparse areas. The latest analysis, GEOS ODAS5.2, is diagnosed through detailed studies of the statistics of the innovations and analysis departures, comparisons with independent data, and integrated values such as volume transport. Finally, the climatologies of temperature and salinity fields from the Argo era, 2002-2011, are presented and compared with the WOA09.

  11. Benefits of hosted payload architectures for improved GEO SSA

    Science.gov (United States)

    Vallado, D.; Lowe, J.; Anderson, J.

    2011-09-01

    Maintaining a precise catalog of objects in and near the GEO belt is difficult for a variety of reasons. Optical Hosted Payloads (HP) on commercial satellites have been suggested as a solution to provide accurate, persistent catalog updates to augment existing data or even relieve schedule burden on traditional tracking systems. However, significant questions remain about what architecture requirements are necessary for stable orbit determination solutions, accuracy improvements over traditional tracking systems, and optimal catalog coverage. System trades are performed using COTS software to determine the influence of number, frequency, and accuracy of observations on orbit solution stability and uncertainty. System configurations are also evaluated against catalog coverage metrics such as number and percent of objects observed, number of tracks per day, and revisit times. Initial results show that some assumed configurations can produce stable, accurate orbit solutions for most of the catalog in and near GEO. Fusing observations from HP sensors with traditional ground data may yield dramatic improvements in positional uncertainty of one to two orders of magnitude, often with multiple observations each day.

  12. Geo-Informatics in India: Major Milestones and Present Scenario

    Science.gov (United States)

    Gupta, S.; Karnatak, H.; Raju, P. L. N.

    2016-06-01

    Geo-informatics has emerged globally as a useful tool to address spatial problems with significant societal implications that require integrative and innovative approaches for analysis, modelling, managing, and archiving of extensive and diverse data sets. Breakneck technological development and availability of satellite based data and information services in public domain along with real time geo-data n through participatory approaches, in the two last decades have led to a sea-change in our know-how of our natural resources and their effective management at various levels. It has led to a realization that every phenomena and requirement in our day to day life has some spatial, or geographic component that can be predicted and governed more effectively through geoinformatics tool. India also has come a long way in effective utilization of geoinformatics for various applications. This quantum leap owes its foundation in a humble beginning about half century back and almost parallel developments in the country's space programme to a current level where it touches almost all areas of life and living. Though geoinformatics technology (GIT) is believed to reach satisfactory level in the country, Indian geospatial community faces critical challenges with respect to research, education and training along with enhanced the access to the stakeholders and mobilization of the workforce, that are crucial in further penetration of this technology in context to India's development. In this paper we have critically reviewed milestones of GI development and its current utilization status in Indian context.

  13. Geo-Agents: Design and Implement

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Geo-Agents, a multi-agent system that processes distr ib utedgeospatial information and geospatial service was presented. Firstly, the requirement for distributed geographical information process was discussed, and the architecture of Geo-Agents was introduced. Then in-depth discussions were r aised on agent system implementation, such as the basic agent, agent advertising , message passing, and collaborating. An example was also given to explain the p roblem solving process.

  14. Optical intersatellite links - Application to commercial satellite communications

    Science.gov (United States)

    Paul, D.; Faris, F.; Garlow, R.; Inukai, T.; Pontano, B.; Razdan, R.; Ganz, Aura; Caudill, L.

    1992-01-01

    Application of optical intersatellite links for commercial satellite communications services is addressed in this paper. The feasibility of commercialization centers around basic issues such as the need and derived benefits, implementation complexity and overall cost. In this paper, commercialization of optical ISLs is assessed in terms of the services provided, systems requirements and feasibility of appropriate technology. Both long- and short-range ISLs for GEO-GEO, GEO-LEO and LEO applications are considered. Impact of systems requirements on the payload design and use of advanced technology in reducing its mass, power, and volume requirements are discussed.

  15. Towards the creation of a European Network of Earth Observation Networks within GEO. The ConnectinGEO project.

    Science.gov (United States)

    Masó, Joan; Serral, Ivette; Menard, Lionel; Wald, Lucien; Nativi, Stefano; Plag, Hans-Peter; Jules-Plag, Shelley; Nüst, Daniel; Jirka, Simon; Pearlman, Jay; De Maziere, Martine

    2015-04-01

    ConnectinGEO (Coordinating an Observation Network of Networks EnCompassing saTellite and IN-situ to fill the Gaps in European Observations" is a new H2020 Coordination and Support Action with the primary goal of linking existing Earth Observation networks with science and technology (S&T) communities, the industry sector, the Group on Earth Observations (GEO), and Copernicus. ConnectinGEO aims to facilitate a broader and more accessible knowledge base to support the needs of GEO, its Societal Benefit Areas (SBAs) and the users of the Global Earth Observing System of Systems (GEOSS). A broad range of subjects from climate, natural resources and raw materials, to the emerging UN Sustainable Development Goals (SDGs) will be addressed. The project will generate a prioritized list of critical gaps within available observation data and models to translate observations into practice-relevant knowledge, based on stakeholder consultation and systematic analysis. Ultimately, it will increase coherency of European observation networks, increase the use of Earth observations for assessments and forecasts and inform the planning for future observation systems. ConnectinGEO will initiate a European Network of Earth Observation Networks (ENEON) that will encompass space-based, airborne and in-situ observations networks. ENEON will be composed by project partners representing thematic observation networks along with the GEOSS Science and Technology Stakeholder Network, GEO Communities of Practices, Copernicus services, Sentinel missions and in-situ support data representatives, representatives of the space-based, airborne and in-situ observations European networks (e.g. EPOS, EMSO and GROOM, etc), representatives of the industry sector and European and national funding agencies, in particular those participating in the future ERA-PlaNET. At the beginning, the ENEON will be created and managed by the project. Then the management will be transferred to the network itself to ensure

  16. GEOS Code Development Road Map - May, 2013

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Scott [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Settgast, Randolph [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fu, Pengcheng [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Antoun, Tarabay [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ryerson, F. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-05-03

    GEOS is a massively parallel computational framework designed to enable HPC-based simulations of subsurface reservoir stimulation activities with the goal of optimizing current operations and evaluating innovative stimulation methods. GEOS will enable coupling of different solvers associated with the various physical processes occurring during reservoir stimulation in unique and sophisticated ways, adapted to various geologic settings, materials and stimulation methods. The overall architecture of the framework includes consistent data structures and will allow incorporation of additional physical and materials models as demanded by future applications. Along with predicting the initiation, propagation and reactivation of fractures, GEOS will also generate a seismic source term that can be linked with seismic wave propagation codes to generate synthetic microseismicity at surface and downhole arrays. Similarly, the output from GEOS can be linked with existing fluid/thermal transport codes. GEOS can also be linked with existing, non-intrusive uncertainty quantification schemes to constrain uncertainty in its predictions and sensitivity to the various parameters describing the reservoir and stimulation operations. We anticipate that an implicit-explicit 3D version of GEOS, including a preliminary seismic source model, will be available for parametric testing and validation against experimental and field data by Oct. 1, 2013.

  17. Remote sensing of Gulf Stream using GEOS-3 radar altimeter

    Science.gov (United States)

    Leitao, C. D.; Huang, N. E.; Parra, C. G.

    1978-01-01

    Radar altimeter measurements from the GEOS-3 satellite to the ocean surface indicated the presence of expected geostrophic height differences across the the Gulf Stream. Dynamic sea surface heights were found by both editing and filtering the raw sea surface heights and then referencing these processed data to a 5 minute x 5 minute geoid. Any trend between the processed data and the geoid was removed by subtracting out a linear fit to the residuals in the open ocean. The mean current velocity of 107 + or - 29 cm/sec calculated from the dynamic heights for all orbits corresponded with velocities obtained from hydrographic methods. Also, dynamic topographic maps were produced for August, September, and October 1975. Results pointed out limitations in the accuracy of the geoid, height anomaly deteriorations due to filtering, and lack of dense time and space distribution of measurements.

  18. Geo-Information (Lake Data Service Based on Ontology

    Directory of Open Access Journals (Sweden)

    Long-hua He

    2007-12-01

    Full Text Available Recently ontology research has received much attention in geo-information science and the concept of ontology is very important for spatial information concept modeling and data sharing, classification of geographical classes. More importantly, it enriches the semantic theory of spatial information. Geo-information services and geo-information interpretation and extraction are the two main applications of geo-ontology. Ontologies have great application potential for geo-information service.

  19. Trace Gas Measurements from the GeoTASO and GCAS Airborne Instruments: An Instrument and Algorithm Test-Bed for Air Quality Observations from Geostationary Orbit

    Science.gov (United States)

    Nowlan, C. R.; Liu, X.; Janz, S. J.; Leitch, J. W.; Al-Saadi, J. A.; Chance, K.; Cole, J.; Delker, T.; Follette-Cook, M. B.; Gonzalez Abad, G.; Good, W. S.; Kowalewski, M. G.; Loughner, C.; Pickering, K. E.; Ruppert, L.; Soo, D.; Szykman, J.; Valin, L.; Zoogman, P.

    2016-12-01

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) and the GEO-CAPE Airborne Simulator (GCAS) instruments are pushbroom sensors capable of making remote sensing measurements of air quality and ocean color. Originally developed as test-bed instruments for the Geostationary Coastal and Air Pollution Events (GEO-CAPE) decadal survey, these instruments are now also part of risk reduction for the upcoming Tropospheric Emissions: Monitoring of Pollution (TEMPO) and Geostationary Environment Monitoring Spectrometer (GEMS) geostationary satellite missions, and will provide validation capabilities after the satellite instruments are in orbit. GeoTASO and GCAS flew on two different aircraft in their first intensive air quality field campaigns during the DISCOVER-AQ missions over Texas in 2013 and Colorado in 2014. GeoTASO was also deployed in 2016 during the KORUS-AQ field campaign to make measurements of trace gases and aerosols over Korea. GeoTASO and GCAS collect spectra of backscattered solar radiation in the UV and visible that can be used to derive 2-D maps of trace gas columns below the aircraft at spatial resolutions on the order of 250 x 500 m. We present spatially resolved maps of trace gas retrievals of ozone, nitrogen dioxide, formaldehyde and sulfur dioxide over urban areas and power plants from flights during the field campaigns, and comparisons with data from ground-based spectrometers, in situ monitoring instruments, and satellites.

  20. Improvement of orbit determination accuracy for Beidou Navigation Satellite System with Two-way Satellite Time Frequency Transfer

    Science.gov (United States)

    Tang, Chengpan; Hu, Xiaogong; Zhou, Shanshi; Guo, Rui; He, Feng; Liu, Li; Zhu, Lingfeng; Li, Xiaojie; Wu, Shan; Zhao, Gang; Yu, Yang; Cao, Yueling

    2016-10-01

    The Beidou Navigation Satellite System (BDS) manages to estimate simultaneously the orbits and clock offsets of navigation satellites, using code and carrier phase measurements of a regional network within China. The satellite clock offsets are also directly measured with Two-way Satellite Time Frequency Transfer (TWSTFT). Satellite laser ranging (SLR) residuals and comparisons with the precise ephemeris indicate that the radial error of GEO satellites is much larger than that of IGSO and MEO satellites and that the BDS orbit accuracy is worse than GPS. In order to improve the orbit determination accuracy for BDS, a new orbit determination strategy is proposed, in which the satellite clock measurements from TWSTFT are fixed as known values, and only the orbits of the satellites are solved. However, a constant systematic error at the nanosecond level can be found in the clock measurements, which is obtained and then corrected by differencing the clock measurements and the clock estimates from orbit determination. The effectiveness of the new strategy is verified by a GPS regional network orbit determination experiment. With the IGS final clock products fixed, the orbit determination and prediction accuracy for GPS satellites improve by more than 50% and the 12-h prediction User Range Error (URE) is better than 0.12 m. By processing a 25-day of measurement from the BDS regional network, an optimal strategy for the satellite-clock-fixed orbit determination is identified. User Equivalent Ranging Error is reduced by 27.6% for GEO satellites, but no apparent reduction is found for IGSO/MEO satellites. The SLR residuals exhibit reductions by 59% and 32% for IGSO satellites but no reductions for GEO and MEO satellites.

  1. File Specification for GEOS-5 FP-IT (Forward Processing for Instrument Teams)

    Science.gov (United States)

    Lucchesi, R.

    2013-01-01

    The GEOS-5 FP-IT Atmospheric Data Assimilation System (GEOS-5 ADAS) uses an analysis developed jointly with NOAA's National Centers for Environmental Prediction (NCEP), which allows the Global Modeling and Assimilation Office (GMAO) to take advantage of the developments at NCEP and the Joint Center for Satellite Data Assimilation (JCSDA). The GEOS-5 AGCM uses the finite-volume dynamics (Lin, 2004) integrated with various physics packages (e.g, Bacmeister et al., 2006), under the Earth System Modeling Framework (ESMF) including the Catchment Land Surface Model (CLSM) (e.g., Koster et al., 2000). The GSI analysis is a three-dimensional variational (3DVar) analysis applied in grid-point space to facilitate the implementation of anisotropic, inhomogeneous covariances (e.g., Wu et al., 2002; Derber et al., 2003). The GSI implementation for GEOS-5 FP-IT incorporates a set of recursive filters that produce approximately Gaussian smoothing kernels and isotropic correlation functions. The GEOS-5 ADAS is documented in Rienecker et al. (2008). More recent updates to the model are presented in Molod et al. (2011). The GEOS-5 system actively assimilates roughly 2 × 10(exp 6) observations for each analysis, including about 7.5 × 10(exp 5) AIRS radiance data. The input stream is roughly twice this volume, but because of the large volume, the data are thinned commensurate with the analysis grid to reduce the computational burden. Data are also rejected from the analysis through quality control procedures designed to detect, for example, the presence of cloud. To minimize the spurious periodic perturbations of the analysis, GEOS-5 FP-IT uses the Incremental Analysis Update (IAU) technique developed by Bloom et al. (1996). More details of this procedure are given in Appendix A. The analysis is performed at a horizontal resolution of 0.625-degree longitude by 0.5-degree latitude and at 72 levels, extending to 0.01 hPa. All products are generated at the native resolution of the

  2. Using geo-topographic materials for environmental protection

    Directory of Open Access Journals (Sweden)

    Saša T. Bakrač

    2011-07-01

    Full Text Available In accordance with the requirements for the protection and development of environment, the usage of spatial data represents a specific need for different kinds of geographical and cartographical information. Theoretical and practical understanding of these requirements, with existing experiences and the use of appropriate standards, help in the process of solving particular ecological problems. In this paper, the analysis (theoretical understanding of the problem and the comparison of models will try to point out the importance, requirements and possibilities of using existing data from different geo-topographical materials such as charts at different scales in analog as well as digital forms. Sources of information about an area: Cartographic-analytic collecting of spatial information for environmental purposes is carried out mainly from the following sources: satellite images, geographic information systems / Environmental Information Systems (GIS / EIS, Geo-topographic materials in analogue and digital (especially maps forms and physical measurements of ambient environment. Types of maps which can be used for environmental protection: Base maps are widely used mostly for military purposes. Being highly detailed, these maps can be largely used for the purposes of environmental protection, especially topographic maps of a scale of 1:25 000 to 1:200 000 and 1:250 000. Thematic maps primarily give information on specific locations and specific content. For the purposes of environmental protection and improvement, thematic maps with specific topics are constructed most frequently. Combined maps are specific and they are a combination of base and thematic maps. These are, for example, political, travel, touristic, hydrological, and synoptic maps. Synthetic maps show the results and analysis of data collected. They cannot display all the characteristics or information related to the environment, especially data about complex ecosystems. Conclusion

  3. Geo-social visual analytics

    Directory of Open Access Journals (Sweden)

    Wei Luo

    2014-06-01

    Full Text Available Spatial analysis and social network analysis typically consider social processes in their own specific contexts, either geographical or network space. Both approaches demonstrate strong conceptual overlaps. For example, actors close to each other tend to have greater similarity than those far apart; this phenomenon has different labels in geography (spatial autocorrelation and in network science (homophily. In spite of those conceptual and observed overlaps, the integration of geography and social network context has not received the attention needed in order to develop a comprehensive understanding of their interaction or their impact on outcomes of interest, such as population health behaviors, information dissemination, or human behavior in a crisis. In order to address this gap, this paper discusses the integration of geographic with social network perspectives applied to understanding social processes in place from two levels: the theoretical level and the methodological level. At the theoretical level, this paper argues that the concepts of nearness and relationship in terms of a possible extension of the First Law of Geography are a matter of both geographical and social network distance, relationship, and interaction. At the methodological level, the integration of geography and social network contexts are framed within a new interdisciplinary field:~visual analytics, in which three major application-oriented subfields (data exploration, decision-making, and predictive analysis are used to organize discussion. In each subfield, this paper presents a theoretical framework first, and then reviews what has been achieved regarding geo-social visual analytics in order to identify potential future research.

  4. GeoSEA: Geodetic Earthquake Observatory on the Seafloor

    Science.gov (United States)

    Kopp, Heidrun; Lange, Dietrich; Flueh, Ernst R.; Petersen, Florian; Behrmann, Jan-Hinrich; Devey, Colin

    2014-05-01

    Space geodetic observations of crustal deformation have contributed greatly to our understanding of plate tectonic processes in general, and plate subduction in particular. Measurements of interseismic strain have documented the active accumulation of strain, and subsequent strain release during earthquakes. However, techniques such as GPS cannot be applied below the water surface because the electromagnetic energy is strongly attenuated in the water column. Evidence suggests that much of the elastic strain build up and release (and particularly that responsible for both tsunami generation and giant earthquakes) occurs offshore. To quantify strain accumulation and assess the resultant hazard potential we urgently need systems to resolve seafloor crustal deformation. Here we report on first results of sea trials of a newly implemented seafloor geodesy array. The GeoSEA (Geodetic Earthquake Observatory on the Seafloor) array consists of a seafloor transponder network comprising 35 units and a wave glider acting as a surface unit (GeoSURF) to ensure satellite correspondence, data transfer and monitor system health. Seafloor displacement occurs in the horizontal (x,y) and vertical direction (z). The vertical displacement is measured by monitoring pressure variations at the seafloor. Horizontal seafloor displacement can be measured either using an acoustic/GPS combination to provide absolute positioning (requiring a suitably equipped vessel to perform repeated cruises to provide the GPS fixes) or by long-term acoustic telemetry between different beacons fixed on the seafloor to determine relative distances by using the travel time observations to each other, which is the technique tested during our short sea trials. For horizontal direct path measurements, the system utilizes acoustic ranging techniques with a ranging precision better than 15 mm and long term stability over 2 km distances. Vertical motion is obtained from pressure gauges. Integrated inclinometers

  5. The Population of Optically Faint GEO Debris

    Science.gov (United States)

    Seitzer, Patrick; Barker, Ed; Buckalew, Brent; Burkhardt, Andrew; Cowardin, Heather; Frith, James; Gomez, Juan; Kaleida, Catherine; Lederer, Susan M.; Lee, Chris H.

    2016-01-01

    The 6.5-m Magellan telescope 'Walter Baade' at the Las Campanas Observatory in Chile has been used for spot surveys of the GEO orbital regime to study the population of optically faint GEO debris. The goal is to estimate the size of the population of GEO debris at sizes much smaller than can be studied with 1-meter class telescopes. Despite the small size of the field of view of the Magellan instrument (diameter 0.5-degree), a significant population of objects fainter than R = 19th magnitude have been found with angular rates consistent with circular orbits at GEO. We compare the size of this population with the numbers of GEO objects found at brighter magnitudes by smaller telescopes. The observed detections have a wide range in characteristics starting with those appearing as short uniform streaks. But there are a substantial number of detections with variations in brightness, flashers, during the 5-second exposure. The duration of each of these flashes can be extremely brief: sometimes less than half a second. This is characteristic of a rapidly tumbling object with a quite variable projected size times albedo. If the albedo is of the order of 0.2, then the largest projected size of these objects is around 10-cm. The data in this paper was collected over the last several years using Magellan's IMACS camera in f/2 mode. The analysis shows the brightness bins for the observed GEO population as well as the periodicity of the flashers. All objects presented are correlated with the catalog: the focus of the paper will be on the uncorrelated, optically faint, objects. The goal of this project is to better characterize the faint debris population in GEO that access to a 6.5-m optical telescope in a superb site can provide.

  6. Radio occultation based on BeiDou satellite navigation

    Science.gov (United States)

    Jiang, Hu; Hu, Haiying; Shen, Xue-min; Gong, Wenbin; Zhang, Yonghe

    2014-11-01

    With the development of GNSS systems, it has become a tendency that radio occultation is used to sense the Earth's atmosphere. By this means, the moisture, temperature, pressure, and total electron content can be derived. Based on the sensing results, more complicated models for atmosphere might come into being. Meteorology well benefits from this technology. As scheduled, the BD satellite navigation system will have a worldwide coverage by the end of 2020. Radio occultation studies in China have been highlighted in the recent decade. More and more feasibilities reports have been published in either domestic or international journals. Herein, some scenarios are proposed to assess the coverage of radio occultation based on two different phases of BD satellite navigation system. Phase one for BD is composed of GEO,IGSO and several MEO satellites. Phase two for BD consists mostly of 24 MEO satellites, some GEO and IGSO satellites. The characteristics of radio occultation based on these two phases are presented respectively.

  7. Graphics Processing Units (GPU) and the Goddard Earth Observing System atmospheric model (GEOS-5): Implementation and Potential Applications

    Science.gov (United States)

    Putnam, William M.

    2011-01-01

    Earth system models like the Goddard Earth Observing System model (GEOS-5) have been pushing the limits of large clusters of multi-core microprocessors, producing breath-taking fidelity in resolving cloud systems at a global scale. GPU computing presents an opportunity for improving the efficiency of these leading edge models. A GPU implementation of GEOS-5 will facilitate the use of cloud-system resolving resolutions in data assimilation and weather prediction, at resolutions near 3.5 km, improving our ability to extract detailed information from high-resolution satellite observations and ultimately produce better weather and climate predictions

  8. The new era for geo-information

    Institute of Scientific and Technical Information of China (English)

    LI DeRen; SHAO ZhenFeng

    2009-01-01

    Along with the forthcoming of Google Earth, Virtual Earth, the next generation of Internet, Web 2.0, grid computing and smart sensor web, comes the new era for geo-information. In this paper, main features of new geo-information era are discussed. This new era is characterized by these features: serviced users are extended from professionals to all public users, the users are data and information providers as well, geospatial data provided are no longer measurement-by-specification but measurement-on-demand through smart sensor web, and services are transferred from being data-driven to application-driven. Such problems as out-of-order issues in geographic data collection and information proliferation, quality issues in geographic information updating, security issues in geographic information services, privacy issues in sharing geographic information and property issues in sharing geographic information, which are brought about by new geo-information era, especially those confronted in geo-information science and geo-spatial information industry, are analyzed. Then strategies concerning standards, planning, laws, technology and applications are proposed.

  9. The Population of Optically Faint GEO Debris

    Science.gov (United States)

    Seitzer, P.; Barker, E.; Buckalew, B.; Burkhardt, A.; Cowardin, H.; Frith, J.; Kaleida, C.; Lederer, S.; Lee, C.

    2016-09-01

    The 6.5-m Magellan telescope, 'Walter Baade', at the Las Campanas Observatory in Chile has been used for spot surveys of the geosynchronous Earth orbit (GEO) regime to study the population of optically faint GEO debris. The goal is to estimate the population of GEO debris at sizes much smaller than can be studied with 1-meter class telescopes. Despite the small field of view of the Magellan instrument (diameter 0.5-degree), a significant population of objects fainter than R = 19th magnitude has been found with angular rates consistent with circular orbits at GEO. We compare the size of this population with the numbers of GEO objects found at brighter magnitudes by smaller telescopes. The detections have a wide range of characteristics starting with those appearing as short uniform streaks. But there are a substantial number of detections that vary in brightness ("flashers") during the 5-second exposure. The duration of each of these flashes can be extremely brief: sometimes less than half a second. This is characteristic of a rapidly tumbling object with a quite variable projected product of size * albedo. If the albedo is of the order of 0.2, then the largest projected size of these objects is around 10-cm.

  10. Preface: BeiDou Navigation Satellite System (BDS)/GNSS+: Recent progress and new applications

    Science.gov (United States)

    Jin, Shuanggen

    2017-02-01

    Nowadays, the new China's BeiDou Navigation Satellite System (BDS) has been developed well. At the end of 2016, over 23 BDS satellites were launched, including five geostationary Earth orbit (GEO) satellites, five inclined geosynchronous orbit (IGSO) satellites and nine medium Earth orbit (MEO) satellites. The current BDS service covers China and most Asia-Pacific regions with accuracy of better than 10 m in positioning, 0.2 m/s in velocity and 50 ns in timing. The BDS with global coverage will be completely established by 2020 with five GEO satellites and 30 MEO satellites. The main function of BDS is the positioning, navigation and timing (PNT) as well as short message communications. Together with the United States' GPS, Russia's GLONASS and the European Union's Galileo system as well as other regional augmentation systems, more new applications of multi-Global Navigation Satellite Systems (GNSS) will be exploited and realized in the next decades.

  11. An analysis of the wide area differential method of geostationary orbit satellites

    Institute of Scientific and Technical Information of China (English)

    CAI ChengLin; LI XiaoHui; WU HaiTao

    2009-01-01

    This work aims to obtain a wide area differential method for geostationary orbit (GEO) constellation. A comparison between the dilution of precision (DOP) of four-dimensional (4D) calculation including satellite clock errors and ephemeris errors and that of three-dimensional (3D) calculation only including ephemeris errors with the inverse positioning theory of GPS shows the conclusion that all the 3D PDOPs are greatly reduced. Based on this, a basic idea of correcting satellite clock errors and ephem-eris errors apart is put forward, and moreover, a specific method of separation is proposed. Satellite clock errors are separated in a master station with time synchronization, and all the remaining pseudo-range errors after the satellite clock errors have been deducted are used to work out ephemeris corrections of all GEO satellites. By a comparative analysis of user positioning accuracy before and after differential, the wide area differential method is verified to be quite valid for GEO constellation.

  12. Study on Zero-Doppler Centroid Control for GEO SAR Ground Observation

    Directory of Open Access Journals (Sweden)

    Yicheng Jiang

    2014-01-01

    Full Text Available In geosynchronous Earth orbit SAR (GEO SAR, Doppler centroid compensation is a key step for imaging process, which could be performed by the attitude steering of a satellite platform. However, this zero-Doppler centroid control method does not work well when the look angle of radar is out of an expected range. This paper primarily analyzes the Doppler properties of GEO SAR in the Earth rectangular coordinate. Then, according to the actual conditions of the GEO SAR ground observation, the effective range is presented by the minimum and maximum possible look angles which are directly related to the orbital parameters. Based on the vector analysis, a new approach for zero-Doppler centroid control in GEO SAR, performing the attitude steering by a combination of pitch and roll rotation, is put forward. This approach, considering the Earth’s rotation and elliptical orbit effects, can accurately reduce the residual Doppler centroid. All the simulation results verify the correctness of the range of look angle and the proposed steering method.

  13. Geostationary Coastal and Air Pollution Events (GeoCAPE) Filter Radiometer (FR)

    Science.gov (United States)

    Kotecki, Carl; Chu, Martha; Wilson, Mark; Clark, Mike; Nanan, Bobby; Matson, Liz; McBirney, Dick; Smith, Jay; Earle, Paul; Choi, Mike; Stoneking, Eric; Luu, Kequan; Swinski, J. P.; Secunda, Mark; Brall, Aron; Verma, Sanjay; Hartman, Kathy R.

    2014-01-01

    The GeoCAPE Filter Radiometer (FR) Study is a different instrument type than all of the previous IDL GeoCape studies. The customer primary goals are to keep mass, volume and cost to a minimum while meeting the science objectives and maximizing flight opportunities by fitting on the largest number of GEO accommodations possible. Minimize total mission costs by riding on a commercial GEO satellite. For this instrument type, the coverage rate, km 2 min, was significantly increased while reducing the nadir ground sample size to 250m. This was accomplished by analyzing a large 2d area for each integration period. The field of view will be imaged on a 4k x 4k detector array of 15 micrometer pixels. Each ground pixel is spread over 2 x 2 detector pixels so the instantaneous field of view (IFOV) is 2048 X 2048 ground pixels. The baseline is, for each field of view 50 sequential snapshot images are taken, each with a different filter, before indexing the scan mirror to the next IFOV. A delta would be to add additional filters.

  14. Quality Management of Reference Geo-Information

    Science.gov (United States)

    Jakobsson, A.; Hopfstock, A.; Beare, M.; Patrucco, R.

    2013-05-01

    This paper will introduce how quality of geo-information can be managed when the production environment is no longer inside one organization (e.g. collection of data is contracted out) or data is compiled from various sources like in case of Spatial Data Infrastructures (SDIs). The bases for quality management of reference geo-information are discussed using three viewpoints; data, process and organization and user centric viewpoints. These viewpoints can be met using ISO 19157 and ISO 19158 standards together with ESDIN developed Quality Model and Data Quality Services Framework (DQSF). Two different services are identified a Data Quality Web Service and a Data User Web Service. We discuss how these principles and services are implemented now within EuroGeographics and Ordnance Survey of Great Britain. Further development will be done during the European Location Framework (ELF) project, which is providing a single source of reference geo-information for Europe during 2013-2016.

  15. Geo-communication and information design

    DEFF Research Database (Denmark)

    Brodersen, Lars

    2009-01-01

    This article is an abstract of the book 'Geo-communication and information design'. The work involved in the book was inspired by the author's sense of wonder that there were apparently no existing theories, models etc. capable of identifying and choosing the content of information in systematic...... of processes, procedures, factors, relations etc., all forming parts of a theory on geo-communication and information design. How do we decide whether to transmit content A or content B to another person? We make a decision. Making decisions does not normally give rise to difficulties, although a great deal...... and controlled basis? The book 'Geo-communication and information design' seeks to provide an answer to this fundamental question....

  16. Detailed gravimetric geoid for the GEOS-C altimeter calibration area

    Science.gov (United States)

    Marsh, J. G.; Vincent, S.

    1974-01-01

    The GEOS-C spacecraft scheduled for launch in late 1974 will carry a radar altimeter for the purpose of measuring sea surface topography. In order to calibrate and evaluate the performance of the altimeter system, ground truth data are required. In this respect a detailed gravimetric geoid has been computed for the GEOS-C altimeter calibration area in the Atlantic Ocean off the East Coast of the U.S. This geoid is based upon a combination of mean free air surface gravity anomalies and the Goddard Space Flight Center GEM-6 satellite-derived spherical harmonic coefficients. Surface gravity anomalies have been used to provide information on the short wave length undulations of the geoid while the satellite-derived coefficients have provided information on the long wave length components. As part of these analyses, GSFC, SAO and OSU satellite-derived gravity models were used in the computations. Although geoid heights based upon the various satellite models differed by as much as 30 meters in the Southern Hemisphere, the differences in this Atlantic Ocean area were less than 4 meters.

  17. User Defined Geo-referenced Information

    DEFF Research Database (Denmark)

    Konstantas, Dimitri; Villalba, Alfredo; di Marzo Serugendo, Giovanna

    2009-01-01

    The evolution of technology allow us today to extent the “location based services” to fine grained services and allow any mobile user to create location based information and make it available to anyone interested. This evolution open the way for new services and applications for the mobile users....... In this paper we present two novel mobile and wireless collaborative services and concepts, the Hovering Information, a mobile, geo-referenced content information management system, and the QoS Information service, providing user observed end-to-end infrastructure geo-related QoS information....

  18. Global GEO survey subsystem of the ISON

    Science.gov (United States)

    Molotov, Igor; Agapov, Vladimir; Rumyantsev, Vasiliy; Biryukov, Vadim; Kornienko, Gennadiy; Litvinenko, Elena; Vikhristenko, Alexander; Zalles, Rodolfo; Guseva, Irina; Inasaridze, Raguli

    Dedicated subsystem of the International Scientific Optical Network (ISON) is created in order to provide the regular monitoring of the objects brighter than 15m at GEO region. For GEO longitudes between 31.5W and 90E a survey mode is implemented in a zone of ±16° width with respect to equator, for longitudes between 90E and 210W the selective areas are surveyed regularly in a zone of ±10° width, and for longitudes between 135W and 1 E the periodic observations are arranged in a zone of ±1° width. Initially existing astrographs of 23 cm and 40 cm aperture with FOV of 30'x30' were involved into the work. Then the dedicated 22-cm aperture telescope installed on the automated mount was elaborated. This new telescope having FOV of 4° x4° can provide up to 5000 measurements for around 400 GEO and HEO (mainly GTO) objects per night. Currently the six similar 22-cm aperture telescopes at different stages of operations are working in Tiraspol (Pridnestrovie), Nauchniy (Crimea, Ukraine), Pulkovo (St.-Petersburg, Russia), Kitab (Uzbekistan) and Ussuriysk (Far East, Russia) observation facilities. During the year of 2008 similar telescopes will be installed in Abastumani (Georgia), Milkovo (Kamchatka, Russia), Tarija (Bolivia), Blagoveshchensk (Far East, Russia) and Gissar (Tadjikistan). Since 2009 the subsystem will provide surveying capability for the GEO region in global scale both by longitude (0° -360° ) and inclination (0° -20° ). The trial operations of the first fully automated 22-cm telescope during 2007 (the part of GEO arc between 31.5W and 90E was surveyed about 60 times) showed existing large gap in our knowledge of space debris populations at GEO region. Few hundreds of uncatalogued respectively bright objects are detected at GEO and GTO orbits. Special processing of obtained short arc tracks for non-correlated object allowed to correlate some of them and thus to discover around 40 new objects. During 2007 slightly less than 200000 measurements

  19. User Defined Geo-referenced Information

    DEFF Research Database (Denmark)

    Konstantas, Dimitri; Villalba, Alfredo; di Marzo Serugendo, Giovanna

    2009-01-01

    The evolution of technology allow us today to extent the “location based services” to fine grained services and allow any mobile user to create location based information and make it available to anyone interested. This evolution open the way for new services and applications for the mobile users....... In this paper we present two novel mobile and wireless collaborative services and concepts, the Hovering Information, a mobile, geo-referenced content information management system, and the QoS Information service, providing user observed end-to-end infrastructure geo-related QoS information....

  20. Spectral Measurements of Geosynchronous Satellites During Glint Season

    Science.gov (United States)

    Chun, F.; Tucker, R.; Weld, E.; Chun, F.; Tippets, R.

    During certain times of the year, stable geosynchronous (GEO) satellites are known to glint or exhibit a very bright specular reflection, which is easily observed through broadband photometric filters. The glints are typically brighter in the Johnson red filter compared to the Johnson blue filter. In previous years, USAFA cadets have developed and refined techniques to take, calibrate and process satellite spectral data taken using a diffraction grating on the USAFA 16-inch, f/8.2 telescope (slitless spectroscopy). To the best of our knowledge, we have not seen any published research on observing glints across the visible spectrum. We present research from an Air Force Academy senior physics capstone project on observing glints off of GEO satellites using slitless spectroscopy. We discuss the calibration of the measurements using solar analog and solar twin stars, as well as results of the spectra of a glinting GEO satellite. A key question is whether a GEO satellite glint is localized in wavelength or equally observed across the entire spectra.

  1. Canadian EdGEO National Workshop Program

    Science.gov (United States)

    Clinton, L. A.; Haidl, F. M.; Hymers, L. A.; van der Flier-Keller, E.

    2009-05-01

    Established in the early 1970s, EdGEO supports locally driven geosciences workshops for Canadian teachers. Workshops are organized by geoscientists and teachers, and typically have field, laboratory and classroom components. Grants of up to $3000 per workshop are available from the National EdGEO Program. By providing educational opportunities for today's teachers and, through them, their students, EdGEO seeks to cultivate a heightened awareness of our planet. EdGEO workshops provide teachers with potential fieldtrip sites for their students and the knowledge, enthusiasm and materials to inspire their students to engage in geoscience. Networking opportunities with local experts promote the importance of the geoscience profession. The expected result is an improved capacity on the part of Canadians to understand the Earth and to make informed decisions, especially with regard to the use of mineral and energy resources, the maintenance and remediation of the environment, and response to geological hazards. There exists a critical need to provide teachers with training and resources to tackle their Earth science curricula. In 2008, EdGEO supported fourteen workshops, with an unprecedented 521 teachers attending. These teachers then used our resources to reach an estimated 14,000 students during that single academic year. EdGEO workshops are locally driven and are therefore very diverse. Workshops are strongly tied to the provincial curriculum, focus on a specific geoscience topic, or may be largely field-based to demonstrate and practice how field activities could be incorporated into Earth science teaching. Many strive to include all of these important components. Geoscientists and teachers work collaboratively to develop and deliver EdGEO workshops to ensure that the activities can be effectively used in the classroom. The length of these professional development opportunities range from two-hour sessions to several days, and can generally accommodate up to twenty

  2. Selection of satellite constellation framework of CAPS

    Institute of Scientific and Technical Information of China (English)

    HAN YanBen; MA LiHua; QIAO QiYuan; YIN ZhiQiang; AI GuoXiang

    2009-01-01

    Based on the idea of transmitting the satellite navigation and positioning system,taking the distribution and variation of the Position Dilution of Precision factor (PDOP),which is closely related with the precision of navigation and positioning,within the China area as the primary criterion,we analyze and discuss the tentative plan of constellation configuration consisting of geosynchronous orbit (GEO) communication satellites and inclined geosynchronous orbit (IGSO) satellites for the transmitting Chinese Area Positioning System (CAPS).We emphatically consider the effect on the PDOP by the three major orbit parameters including the inclination,eccentricity and right ascension of the ascending node (RAAN) of IGSO satellites,to research the strategies of the constellation configuration of CAPS through software emulation.Various constellation configurations are analyzed and compared and the results show that the constellation configuration,consisting of three IGSO communication satellites in three orbits with the same inclination as 50°,the difference in RAAN as 120°and the same "8" shaped ground track centered near 115°E and four or five GEO communication satellites within 60°E to 150°E,can satisfy the requirement that Chinese domain is availably covered end the navigation and positioning with high precision could be obtained.Three relatively excellent constellation configurations are initially suggested and some concerned issues are discussed in this work.

  3. Selection of satellite constellation framework of CAPS

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on the idea of transmitting the satellite navigation and positioning system, taking the distribution and variation of the Position Dilution of Precision factor (PDOP), which is closely related with the precision of navigation and positioning, within the China area as the primary criterion, we analyze and discuss the tentative plan of constellation configuration consisting of geosynchronous orbit (GEO) communication satellites and inclined geosynchronous orbit (IGSO) satellites for the transmitting Chinese Area Positioning System (CAPS). We emphatically consider the effect on the PDOP by the three major orbit parameters including the inclination, eccentricity and right ascension of the ascend- ing node (RAAN) of IGSO satellites, to research the strategies of the constellation configuration of CAPS through software emulation. Various constellation configurations are analyzed and compared and the results show that the constellation configuration, consisting of three IGSO communication satellites in three orbits with the same inclination as 50°, the difference in RAAN as 120° and the same "8" shaped ground track centered near 115°E and four or five GEO communication satellites within 60°E to 150°E, can satisfy the requirement that Chinese domain is availably covered and the navigation and positioning with high precision could be obtained. Three relatively excellent constellation configurations are initially suggested and some concerned issues are discussed in this work.

  4. Model driven geo-information systems development

    NARCIS (Netherlands)

    Morales Guarin, J.M.; Ferreira Pires, Luis; van Sinderen, Marten J.; Williams, A.D.

    Continuous change of user requirements has become a constant for geo-information systems. Designing systems that can adapt to such changes requires an appropriate design methodology that supports abstraction, modularity and other mechanisms to capture the essence of the system and help controlling

  5. Complex Functions with GeoGebra

    Science.gov (United States)

    Breda, Ana Maria D'azevedo; Dos Santos, José Manuel Dos Santos

    2016-01-01

    Complex functions, generally feature some interesting peculiarities, seen as extensions of real functions. The visualization of complex functions properties usually requires the simultaneous visualization of two-dimensional spaces. The multiple Windows of GeoGebra, combined with its ability of algebraic computation with complex numbers, allow the…

  6. Geo-communication and information design

    Directory of Open Access Journals (Sweden)

    Lars Brodersen

    2008-01-01

    Full Text Available This article is an abstract of the book 'Geo-communication and information design'. The work involved in the book was inspired by the author's sense of wonder that there were apparently no existing theories, models etc. capable of identifying and choosing the content of information in systematic and controlled fashion with a view to achieving geo-communication - with a view to achieving agreement regarding issues and their locations. The concrete question on which the book is based is how to choose content A rather than content B in systematic and controlled fashion. The book contains a wide range of processes, procedures, factors, relations etc., all forming parts of a theory on geo-communication and information design. How do we decide whether to transmit content A or content B to another person? We make a decision. Making decisions does not normally give rise to difficulties, although a great deal of debate might occur during the decision-making process. But if the question is extended to include a demand for systematics and consciousness (control in the procedure adopted, the whole issue becomes more complex. How do we decide to transmit content A or content B to another person on a systematic and controlled basis? The book 'Geo-communication and information design' seeks to provide an answer to this fundamental question.

  7. GeoTOA: Geocentric TOA tools

    Science.gov (United States)

    Kerr, Matthew; Ray, Paul

    2014-12-01

    GeoTOA computes the pulse times of arrival (TOAs) at an observatory (or spacecraft) from unbinned Fermi LAT data. Written in Python, the software requires NumPy, matplotlib, SciPy, FSSC Science Tools, and Tempo2 (ascl:1210.015).

  8. Complex Functions with GeoGebra

    Science.gov (United States)

    Breda, Ana Maria D'azevedo; Dos Santos, José Manuel Dos Santos

    2016-01-01

    Complex functions, generally feature some interesting peculiarities, seen as extensions of real functions. The visualization of complex functions properties usually requires the simultaneous visualization of two-dimensional spaces. The multiple Windows of GeoGebra, combined with its ability of algebraic computation with complex numbers, allow the…

  9. Hoe bescherm je geo-informatie?

    NARCIS (Netherlands)

    Welle Donker, F.M.

    2007-01-01

    De overheid maakt geo-informatie steeds vaker openbaar beschikbaar, onder meer via internet. De juridische bescherming van deze gegevens is echter niet altijd goed geregeld. De Amerikaanse gebruikslicenties van de non-profitorganisatie Creative Commons bieden uitkomst. Het overheidsprogramma Ruimte

  10. Geo-neutrino results with Borexino

    Science.gov (United States)

    Roncin, R.; Agostini, M.; Appel, S.; Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Chepurnov, A.; D'Angelo, D.; Davini, S.; Derbin, A.; Di Noto, L.; Drachnev, I.; Etenko, A.; Fomenko, K.; Franco, D.; Gabriele, F.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jedrzejczak, K.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kryn, D.; Laubenstein, M.; Lehnert, B.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Rossi, N.; Schönert, S.; Semenov, D.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Unzhakov, E.; Vishneva, A.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2016-02-01

    Borexino is a liquid scintillator detector primary designed to observe solar neutrinos. Due to its low background level as well as its position in a nuclear free country, Italy, Borexino is also sensitive to geo-neutrinos. Borexino is leading this interdisciplinary field of neutrino geoscience by studying electron antineutrinos which are emitted from the decay of radioactive isotopes present in the crust and the mantle of the Earth. With 2056 days of data taken between December 2007 and March 2015, Borexino observed 77 antineutrino candidates. If we assume a chondritic Th/U mass ratio of 3.9, the number of geo-neutrino events is found to be 23.7+6.5 -5.7(stat) +0.9-0.6 (syst). With this measurement, Borexino alone is able to reject the null geo-neutrino signal at 5.9σ, to claim a geo-neutrino signal from the mantle at 98% C.L. and to restrict the radiogenic heat production for U and Th between 23 and 36 TW.

  11. Surface Pressure Dependencies in the GEOS-Chem-Adjoint System and the Impact of the GEOS-5 Surface Pressure on CO2 Model Forecast

    Science.gov (United States)

    Lee, Meemong; Weidner, Richard

    2016-01-01

    In the GEOS-Chem Adjoint (GCA) system, the total (wet) surface pressure of the GEOS meteorology is employed as dry surface pressure, ignoring the presence of water vapor. The Jet Propulsion Laboratory (JPL) Carbon Monitoring System (CMS) research team has been evaluating the impact of the above discrepancy on the CO2 model forecast and the CO2 flux inversion. The JPL CMS research utilizes a multi-mission assimilation framework developed by the Multi-Mission Observation Operator (M2O2) research team at JPL extending the GCA system. The GCA-M2O2 framework facilitates mission-generic 3D and 4D-variational assimilations streamlining the interfaces to the satellite data products and prior emission inventories. The GCA-M2O2 framework currently integrates the GCA system version 35h and provides a dry surface pressure setup to allow the CO2 model forecast to be performed with the GEOS-5 surface pressure directly or after converting it to dry surface pressure.

  12. GEO 600 and the GEO-HF upgrade program: successes and challenges

    CERN Document Server

    Dooley, K L; Adams, T; Affeldt, C; Bisht, A; Bogan, C; Degallaix, J; Gräf, C; Hild, S; Hough, J; Khalaidovski, A; Lastzka, N; Lough, J; Lück, H; Macleod, D; Nuttall, L; Prijatelj, M; Schnabel, R; Schreiber, E; Slutsky, J; Sorazu, B; Strain, K A; Vahlbruch, H; Was, M; Willke, B; Wittel, H; Danzmann, K; Grote, H

    2015-01-01

    The German-British laser-interferometric gravitational wave detector GEO 600 is in its 14th year of operation since its first lock in 2001. After GEO 600 participated in science runs with other first-generation detectors, a program known as GEO-HF began in 2009. The goal was to improve the detector sensitivity at high frequencies with technologically advanced yet minimally invasive upgrades. Simultaneously, the detector would record science quality data in between commissioning activities. As of early 2014, all of the planned upgrades have been carried out and sensitivity improvements of up to a factor of four at the high-frequency end of the observation band have been achieved. Besides science data collection, an experimental program is ongoing with the goal to further improve the sensitivity and evaluate future detector technologies. We summarize the results of the GEO-HF program to date and discuss its successes and challenges.

  13. Benefits of a Geosynchronous Orbit (GEO) Observation Point for Orbit Determination

    Science.gov (United States)

    Byrne, R.; Griesmeyer, M.; Schmidt, R.; Shaddix, J.; Bodette, D.

    2011-09-01

    Determining orbits of unknown objects is a fundamental space situational awareness activity. The U.S. Space Surveillance Network (SSN) currently relies on ground-based radars, optical telescopes, and the Space Based Space Surveillance (SBSS) System. The SBSS system overcomes many of the pitfalls of optical ground-based systems like limited observation times (e.g. weather and time of day) and measurement uncertainty from atmospheric effects. However, the SBSS satellite is in a low earth orbit (630 km, sun synchronous), and must look “up” for GEO objects. This paper analyzes the potential benefits of a GEO observation point for performing metric observations that are combined with ground-based data. Several different scenarios are considered to quantify the reduction in orbit uncertainty from these types of observations. All results are derived using an Extended Kalman filter (EKF) to process the observations. Orbital uncertainties are expressed in terms of the error covariance.

  14. GEO-6 project for Galileo data scientific utilization

    Science.gov (United States)

    Buresova, Dalia; Lastovicka, Jan; Boska, Josef; Sauli, Petra; Kouba, Daniel; Mosna, Zbysek

    The future GNSS Galileo system offer a number of benefits (e.g. availability of better accuracy positioning, new frequencies bands allowing the implementation of specific techniques, provable time-stamp and location data using SIS authorisation, integrity, better support ad-hoc algorithms for data analysis and other service guarantee for liability and regulated applications) are widely spread among different disciplines. Also applications which are less interesting from the commercial and market point of view could successfully contribute to the numerous social benefits and support the innovation in the international research. The aim of the GEO-6 project "Scientific research Using GNSS" is to propose and broaden scientific utilization of future GNSS Galileo system data in research. It is a joint project of seven institutions from six countries led by the Atos Origin Company from Spain. The core of the project consists from six projects in five priority areas: PA-1 Remote sensing of the ocean using GNSS reflections, PA-2a Investigating GNSS ionospheric data assimilation, PA-2b 3-D gravity wave detection and determination (both PA-2a and PA-2b are ionospheric topics), PA-3 Demonstration of capability for operational forecasting of atmospheric delays, PA-4 GNSS seismometer, PA-5 Spacecraft formation flying using global navigation satellite systems. Institute of Atmospheric Physics, Prague, Czech Republic is responsible for the project PA-2b, where we developed and tested (to the extent allowed by available data) an algorithm and computer code for the 3-D detection of gravity waves and determination of their characteristics. The main drivers of the GEO-6 project are: high levels of accuracy even with the support of local elements, sharing of solutions and results for the worldwide scientific community. The paper will present basic description of the project with more details concerning Czech participation in it.

  15. Designing GeoGebra Applets to Maximize Student Engagement

    Science.gov (United States)

    Paoletti, Teo; Monahan, Ceire; Vishnubhotla, Madhavi

    2017-01-01

    GeoGebra is a free tool that has the potential to change both how and what is taught in mathematics. GeoGebra allows teachers and students to explore various mathematical ideas either through the full applet (https://www.geogebra.org/graphing) or by sharing applets via GeoGebra's Materials site (https://www.geogebra. org/materials/). It has many…

  16. PyGeoTess 0.2.0

    Energy Technology Data Exchange (ETDEWEB)

    2016-07-28

    PyGeoTess is a Python interface module to the GeoTess gridding and earth model library from Sandia National Laboratories. It provides simplified access to a subset of the GeoTess C++ library, and takes advantage of Python's interactive interpreter and inline documentation system.

  17. Charging of space debris in the LEO and GEO regions

    Science.gov (United States)

    Sen, Abhijit; Tiwari, Sanat Kumar

    The near exponential rise of space debris at the satellite orbital altitudes (particularly in the low earth orbit (LEO) region) and the risk they pose for space assets is a source of major concern for all nations engaged in space activities. Considerable efforts are therefore being expended into accurate modeling and tracking of these objects and various ideas for the safe removal of these debris are being explored. The debris objects are likely to acquire a large amount of charge since they are typically found in a plasma environment - such as the earth’s ionospheric plasma in the LEO region (100 kms to 1000 kms) and the radiation belts in the geosynchronous orbit (GEO) region. The consequent flow of electron and ion currents on them lead to the accumulation of a large amount of surface charge and the development of a surface potential on these objects. The influence of the plasma environment on the dynamics and charging of the debris is a relatively unexplored area of Space Situational Awareness (SSA) and Space Debris (SD) research and can be potentially important for the accurate prediction of the long-term evolution of debris orbits and their collision probabilities with other space objects. In this paper we will report on the charging of space debris under a variety of orbital conditions in the LEO and GEO regions using both analytic and particle-in-cell (PIC) modeling. The analytic estimates are obtained using refined Orbit Motion Limited (OML) modeling while the simulation studies are carried out using the SPIS code [1]. In the GEO region account is taken of charging due to photoemission processes as well as energetic beam charging. The PIC approach enables us to study charging of irregularly shaped debris objects as well as differential charging on objects that are composed of patches of conducting and insulated regions. The dynamical consequences of the debris charging on their orbital trajectories and rotational characteristics will be discussed. [1] J

  18. Optimal mission planning of GEO on-orbit refueling in mixed strategy

    Science.gov (United States)

    Chen, Xiao-qian; Yu, Jing

    2017-04-01

    The mission planning of GEO on-orbit refueling (OOR) in Mixed strategy is studied in this paper. Specifically, one SSc will be launched to an orbital slot near the depot when multiple GEO satellites are reaching their end of lives. The SSc replenishes fuel from the depot and then extends the lifespan of the target satellites via refueling. In the mixed scenario, only some of the target satellites could be served by the SSc, and the remaining ones will be fueled by Pseudo SScs (the target satellite which has already been refueled by the SSc and now has sufficient fuel for its operation as well as the fuel to refuel other target satellites is called Pseudo SSc here). The mission sequences and fuel mass of the SSc and Pseudo SScs, the dry mass of the SSc are used as design variables, whereas the economic benefit of the whole mission is used as design objective. The economic cost and benefit models are stated first, and then a mathematical optimization model is proposed. A comprehensive solution method involving enumeration, particle swarm optimization and modification is developed. Numerical examples are carried out to demonstrate the effectiveness of the model and solution method. Economic efficiencies of different OOR strategies are compared and discussed. The mixed strategy would perform better than the other strategies only when the target satellites satisfy some conditions. This paper presents an available mixed strategy scheme for users and analyzes its advantages and disadvantages by comparing with some other OOR strategies, providing helpful references to decision makers. The best strategy in practical applications depends on the specific demands and user preference.

  19. Mobile service for open data visualization on geo-based images

    Science.gov (United States)

    Lee, Kiwon; Kim, Kwangseob; Kang, Sanggoo

    2015-12-01

    Since the early 2010s, governments in most countries have adopted and promoted open data policy and open data platform. Korea are in the same situation, and government and public organizations have operated the public-accessible open data portal systems since 2011. The number of open data and data type have been increasing every year. These trends are more expandable or extensible on mobile environments. The purpose of this study is to design and implement a mobile application service to visualize various typed or formatted public open data with geo-based images on the mobile web. Open data cover downloadable data sets or open-accessible data application programming interface API. Geo-based images mean multi-sensor satellite imageries which are referred in geo-coordinates and matched with digital map sets. System components for mobile service are fully based on open sources and open development environments without any commercialized tools: PostgreSQL for database management system, OTB for remote sensing image processing, GDAL for data conversion, GeoServer for application server, OpenLayers for mobile web mapping, R for data analysis and D3.js for web-based data graphic processing. Mobile application in client side was implemented by using HTML5 for cross browser and cross platform. The result shows many advantageous points such as linking open data and geo-based data, integrating open data and open source, and demonstrating mobile applications with open data. It is expected that this approach is cost effective and process efficient implementation strategy for intelligent earth observing data.

  20. Reconciling bottom-up and top-down carbon flux estimates using NASA's GEOS-Carb modeling system

    Science.gov (United States)

    Ott, L.; Baker, D. F.; Chatterjee, A.; Collatz, G. J.; Gregg, W. W.; Kawa, S. R.; Oda, T.; Rousseaux, C. S.; Wang, J. S.; Weir, B.

    2016-12-01

    NASA's Carbon Monitoring System (CMS) began in 2010 with the goal of better understanding carbon stocks and fluxes using remote sensing observations. Models play a critical role in achieving this goal by integrating diverse observations of the carbon cycle (e.g. vegetation characteristics, ocean color, night lights, precipitation) to produce estimates of flux, which is not directly observable at a global scale. Built around NASA's Goddard Earth Observing System, version 5 (GEOS-5) atmospheric general circulation model and data assimilation system, the GEOS-Carb system supports CMS by providing data-driven, bottom-up and top-down flux estimates and high-resolution global estimates of carbon dioxide concentration. Because all modeling components use a consistent set of meteorological forcing from GEOS-5, this system provides a unique, physically consistent view of the relationship between carbon flux and climate. We will present 1) an overview of the GEOS-Carb modeling system, products, and available web tools, 2) recent results placing 2015, a record-breaking meteorological year, in the context of the 13-year GEOS-Carb record, and 3) future directions in global modeling in support of science policy and satellite mission planning.

  1. Towards Reduced Nickel-Cadmium Battery Cost for Micro Satellites

    OpenAIRE

    1994-01-01

    This paper presents the two Nickel-Cadmium technologies offered by Saft for satellites applications: the space-qualified VOS prismatic cells designed for long term LEO and GEO missions, and the VRE cylindrical cell devoted to launcher activities and to short life LEO missions for mini and micro satellites. It also details Saft's effort to minimize the cost for these cells - in strict compliance with customer's specification and without any changes to the existing product manufacturing process.

  2. Vision Based Geo Navigation Information Retreival

    Directory of Open Access Journals (Sweden)

    Asif Khan

    2016-01-01

    Full Text Available In order to derive the three-dimensional camera position from the monocular camera vision, a geo-reference database is needed. Floor plan is a ubiquitous geo-reference database that every building refers to it during construction and facility maintenance. Comparing with other popular geo-reference database such as geo-tagged photos, the generation, update and maintenance of floor plan database does not require costly and time consuming survey tasks. In vision based methods, the camera needs special attention. In contrast to other sensors, vision sensors typically yield vast information that needs complex strategies to permit use in real-time and on computationally con-strained platforms. This research work show that map-based visual odometer strategy derived from a state-of-the-art structure-from-motion framework is particularly suitable for locally stable, pose controlled flight. Issues concerning drifts and robustness are analyzed and discussed with respect to the original framework. Additionally, various usage of localization algorithm in view of vision has been proposed here. Though, a noteworthy downside with vision-based algorithms is the absence of robustness. The greater parts of the methodologies are delicate to scene varieties (like season or environment changes because of the way that they utilize the Sum of Squared Differences (SSD. To stop that, we utilize the Mutual Information which is exceptionally vigorous toward global and local scene varieties. On the other hand, dense methodologies are frequently identified with drift drawbacks. Here, attempt to take care of this issue by utilizing geo-referenced pictures. The algorithm of localization has been executed and experimental results are available. Vision sensors possess the potential to extract information about the surrounding environment and determine the locations of features or points of interest. Having mapped out landmarks in an unknown environment, subsequent observations

  3. Using GeoRSS to syndicate the spatiotemporal information

    Science.gov (United States)

    Zhao, Bo; Li, Manchun; Jiang, Zhixin

    2007-06-01

    This paper describes a number of ways to encode spatiotemporal information in RSS feeds. As RSS becomes more and more prevalent as a way to publish and share information, it becomes increasingly important that location and time is described in an interoperable manner so that applications can request, aggregate, share and map spatiotemporally tagged feeds. This paper describes the GeoRSS model and encodings. With every RSS item has a timestamp, GeoRSS can represent time property for free. There are three GeoRSS encoding standards, such as W3C Geo, GeoRSS Simple, and GeoRSS GML profile. These standards differ in the number of coordinate systems they can support, and in the number of different geometric shapes they can add to the map to show where the news or event of interest is taking place. Further more, this paper described how to add time attribute to GeoRSS and implement and visualization the GeoRSS feeds through Google Map and Timeline. A few apt illustrations were given to show the powerful functions of GeoRSS in syndicating the spatiotemporal information. GeoRSS leverages this teeming ecosystem for geospatial technology, and with OGC support, GeoRSS is on firm conceptual ground and gains exposure across the industry.

  4. Satellite RNAs and Satellite Viruses.

    Science.gov (United States)

    Palukaitis, Peter

    2016-03-01

    Satellite RNAs and satellite viruses are extraviral components that can affect either the pathogenicity, the accumulation, or both of their associated viruses while themselves being dependent on the associated viruses as helper viruses for their infection. Most of these satellite RNAs are noncoding RNAs, and in many cases, have been shown to alter the interaction of their helper viruses with their hosts. In only a few cases have the functions of these satellite RNAs in such interactions been studied in detail. In particular, work on the satellite RNAs of Cucumber mosaic virus and Turnip crinkle virus have provided novel insights into RNAs functioning as noncoding RNAs. These effects are described and potential roles for satellite RNAs in the processes involved in symptom intensification or attenuation are discussed. In most cases, models describing these roles involve some aspect of RNA silencing or its suppression, either directly or indirectly involving the particular satellite RNA.

  5. Assessment of the detectability of geo-hazards using Google Earth applied to the Three Parallel Rivers Area, Yunnan province of China

    Science.gov (United States)

    Voermans, Michiel; Mao, Zhun; Baartman, Jantiene EM; Stokes, Alexia

    2017-04-01

    Anthropogenic activities such as hydropower, mining and road construction in mountainous areas can induce and intensify mass wasting geo-hazards (e.g. landslides, gullies, rockslides). This represses local safety and socio-economic development, and endangers biodiversity at larger scale. Until today, data and knowledge to construct geo-hazard databases for further assessments are lacking. This applies in particular to countries with a recently emerged rapid economic growth, where there are no previous hazard documentations and where means to gain data from e.g. intensive fieldwork or VHR satellite imagery and DEM processing are lacking. Google Earth (GE, https://www.google.com/earth/) is a freely available and relatively simple virtual globe, map and geographical information program, which is potentially useful in detecting geo-hazards. This research aimed at (i) testing the capability of Google Earth to detect locations of geo-hazards and (ii) identifying factors affecting the diagnosing quality of the detection, including effects of geo-hazard dimensions, environs setting and professional background and effort of GE users. This was tested on nine geo-hazard sites following road segments in the Three Parallel Rivers Area in the Yunnan province of China, where geo-hazards are frequently occurring. Along each road site, the position and size of each geo-hazard was measured in situ. Next, independent diagnosers with varying professional experience (students, researchers, engineers etc.) were invited to detect geo-hazard occurrence along each of the eight sites via GE. Finally, the inventory and diagnostic data were compared to validate the objectives. Rates of detected geo-hazards from 30 diagnosers ranged from 10% to 48%. No strong correlations were found between the type and size of the geo-hazards and their detection rates. Also the years of expertise of the diagnosers proved not to make a difference, opposite to what may be expected. Meanwhile the amount of time

  6. DIGITAL VIDEO BROADCAST RETURN CHANNEL VIA SATELLITE (DVB-RCS HUB FOR SATELLITE BASED E-LEARNING

    Directory of Open Access Journals (Sweden)

    N.G.Vasantha Kumar

    2011-02-01

    Full Text Available This paper discusses in-house designed and developed scale-down DVB-RCS hub along with the performance of the realized hub. This development is intended to support the Satellite Based e-Learning initiative in India. The scale-down DVB-RCS HUB is implemented around a single PC with other subsystems making it very cost effective and unique of its kind. This realization will drastically reduce the total cost of Satellite based Education Networks as very low cost commercially available Satellite Interactive Terminals (SITs complying to open standard could be used at remote locations. The system is successfully tested to work with a commercial SIT using a GEO satellite EDUSAT which is especially dedicated for satellite based e-Learning. The internal detail of the DVB-RCS Forward and Return Link Organization and how it manages the Satellite Interactive Terminals access to the satellite channel using MF-TDMA approach has been described.

  7. Centriolar satellites

    DEFF Research Database (Denmark)

    Tollenaere, Maxim A X; Mailand, Niels; Bekker-Jensen, Simon

    2015-01-01

    Centriolar satellites are small, microscopically visible granules that cluster around centrosomes. These structures, which contain numerous proteins directly involved in centrosome maintenance, ciliogenesis, and neurogenesis, have traditionally been viewed as vehicles for protein trafficking...... highlight newly discovered regulatory mechanisms targeting centriolar satellites and their functional status, and we discuss how defects in centriolar satellite components are intimately linked to a wide spectrum of human diseases....

  8. A Space Based Solar Power Satellite System

    Science.gov (United States)

    Engel, J. M.; Polling, D.; Ustamujic, F.; Yaldiz, R.; et al.

    2002-01-01

    (SPoTS) supplying other satellites with energy. SPoTS is due to be commercially viable and operative in 2020. of Technology designed the SPoTS during a full-time design period of six weeks as a third year final project. The team, organized according to the principles of systems engineering, first conducted a literature study on space wireless energy transfer to select the most suitable candidates for use on the SPoTS. After that, several different system concepts have been generated and evaluated, the most promising concept being worked out in greater detail. km altitude. Each SPoTS satellite has a 50m diameter inflatable solar collector that focuses all received sunlight. Then, the received sunlight is further redirected by means of four pointing mirrors toward four individual customer satellites. A market-analysis study showed, that providing power to geo-stationary communication satellites during their eclipse would be most beneficial. At arrival at geo-stationary orbit, the focused beam has expended to such an extent that its density equals one solar flux. This means that customer satellites can continue to use their regular solar arrays during their eclipse for power generation, resulting in a satellite battery mass reduction. the customer satellites in geo-stationary orbit, the transmitted energy beams needs to be pointed with very high accuracy. Computations showed that for this degree of accuracy, sensors are needed, which are not mainstream nowadays. Therefore further research must be conducted in this area in order to make these high-accuracy-pointing systems commercially attractive for use on the SPoTS satellites around 2020. Total 20-year system lifetime cost for 18 SPoT satellites are estimated at approximately USD 6 billion [FY2001]. In order to compete with traditional battery-based satellite power systems or possible ground based wireless power transfer systems the price per kWh for the customer must be significantly lower than the present one

  9. 3D GEO: AN ALTERNATIVE APPROACH

    OpenAIRE

    2016-01-01

    The expression GEO is mostly used to denote relation to the earth. However it should not be confined to what is related to the earth's surface, as other objects also need three dimensional representation and documentation, like cultural heritage objects. They include both tangible and intangible ones. In this paper the 3D data acquisition and 3D modelling of cultural heritage assets are briefly described and their significance is also highlighted. Moreover the organization of such information...

  10. Satellite theory

    Science.gov (United States)

    Kozai, Y.

    1981-04-01

    The dynamical characteristics of the natural satellite of Mars, Jupiter, Saturn, Uranus and Neptune are analyzed on the basis of the solar tidal perturbation factor and the oblateness factor of the primary planet for each satellite. For the inner satellites, for which the value of the solar tidal factor is much smaller than the planetary oblateness factor, it is shown that the eccentricity and inclination of satellite orbits are generally very small and almost constant; several pairs of inner satellites are also found to exhibit commensurable mean motions, or secular accelerations in mean longitude. In the case of the outer satellites, for which solar perturbations are dominant, secular perturbations and long-period perturbations may be derived by the solution of equations of motion reduced to one degree of freedom. The existence of a few satellites, termed intermediary satellites, for which the solar tidal perturbation is on the order of the planetary oblateness factor, is also observed, and the pole of the orbital plane of the satellite is noted to execute a complex motion around the pole of the planet or the orbital plane of the planet.

  11. Structure of glassy GeO2.

    Science.gov (United States)

    Salmon, Philip S; Barnes, Adrian C; Martin, Richard A; Cuello, Gabriel J

    2007-10-17

    The full set of partial structure factors for glassy germania, or GeO2, were accurately measured by using the method of isotopic substitution in neutron diffraction in order to elucidate the nature of the pair correlations for this archetypal strong glass former. The results show that the basic tetrahedral Ge(O1/2)4 building blocks share corners with a mean inter-tetrahedral Ge-Ô-Ge bond angle of 132(2)°. The topological and chemical ordering in the resultant network displays two characteristic length scales at distances greater than the nearest neighbour. One of these describes the intermediate range order, and manifests itself by the appearance of a first sharp diffraction peak in the measured diffraction patterns at a scattering vector kFSDP≈1.53 Å(-1), while the other describes so-called extended range order, and is associated with the principal peak at kPP = 2.66(1) Å(-1). We find that there is an interplay between the relative importance of the ordering on these length scales for tetrahedral network forming glasses that is dominated by the extended range ordering with increasing glass fragility. The measured partial structure factors for glassy GeO2 are used to reproduce the total structure factor measured by using high energy x-ray diffraction and the experimental results are also compared to those obtained by using classical and first principles molecular dynamics simulations.

  12. GeoICT Uniformity in Flexibility: Analysis of the influence of geoICT coordination on the cooperation between public organisations with geoICT

    NARCIS (Netherlands)

    W. de Vries (Walter Timo)

    2013-01-01

    textabstractThis chapter begins with an empirical case where various public sector organisations in the Netherlands have cooperated with a particular type of technology, geoICT, since 1996. Throughout this document, GeoICT refers to the collection of Information and Communication Technologies (ICT)

  13. The Geo/Geo/1+1 Queueing System with Negative Customers

    Directory of Open Access Journals (Sweden)

    Zhanyou Ma

    2013-01-01

    Full Text Available We study a Geo/Geo/1+1 queueing system with geometrical arrivals of both positive and negative customers in which killing strategies considered are removal of customers at the head (RCH and removal of customers at the end (RCE. Using quasi-birth-death (QBD process and matrix-geometric solution method, we obtain the stationary distribution of the queue length, the average waiting time of a new arrival customer, and the probabilities of servers in busy or idle period, respectively. Finally, we analyze the effect of some related parameters on the system performance measures.

  14. Satellite Type Estination from Ground-based Photometric Observation

    Science.gov (United States)

    Endo, T.; Ono, H.; Suzuki, J.; Ando, T.; Takanezawa, T.

    2016-09-01

    The optical photometric observation is potentially a powerful tool for understanding of the Geostationary Earth Orbit (GEO) objects. At first, we measured in laboratory the surface reflectance of common satellite materials, for example, Multi-layer Insulation (MLI), mono-crystalline silicon cells, and Carbon Fiber Reinforced Plastic (CFRP). Next, we calculated visual magnitude of a satellite by simplified shape and albedo. In this calculation model, solar panels have dimensions of 2 by 8 meters, and the bus area is 2 meters squared with measured optical properties described above. Under these conditions, it clarified the brightness can change the range between 3 and 4 magnitudes in one night, but color index changes only from 1 to 2 magnitudes. Finally, we observed the color photometric data of several GEO satellites visible from Japan multiple times in August and September 2014. We obtained that light curves of GEO satellites recorded in the B and V bands (using Johnson filters) by a ground-base optical telescope. As a result, color index changed approximately from 0.5 to 1 magnitude in one night, and the order of magnitude was not changed in all cases. In this paper, we briefly discuss about satellite type estimation using the relation between brightness and color index obtained from the photometric observation.

  15. Seamless Handovers in Cobra Teardrop Satellite Arrays

    Science.gov (United States)

    Draim, John E.; Cefola, Paul J.; Ernandes, Kenneth J.

    2007-06-01

    Satellite systems provide the most efficient and possibly the only means of achieving two-way global communications with mobile systems (ships, aircraft, and vehicular traffic). To date, such systems have used only circular orbits, either GEO or LEO. Medium altitude elliptical constellations, on the other hand, can provide an efficient and affordable alternative to these architectures. Users also benefit from their very high average and minimum elevation angles, resulting in minimum signal attenuation. Cobra Teardrop is unique in that it employs time synchronized 8-h left- and right-leaning elliptical orbits giving mid-latitude observers the illusion of viewing a single satellite continuously orbiting almost directly overhead! In reality, observers see six different satellites per day, for 4 h each (while in their active duty cycles). By design, Teardrop satellites are physically in very close proximity at the handover points. This favorable geometry can be utilized to achieve a seamless handover from one satellite to the other (not requiring any electronic buffering). Handover is accomplished at the precise instant that the total path lengths from the transmitting station through both satellites to the receiving station are exactly equal. In these improved Cobra Teardrop arrays, an order of magnitude increase in global communications capacity (equivalent GEO slots) can be realized over earlier Basic Cobra systems. For decades into the future, these new orbital systems could satisfy a widely expanding range of commercial, government, and military high data rate communication requirements. These would include, but not be limited to, satellite cellular, air traffic control, meteorological, and combat net radio systems. With these arrays, a much larger number of system operators could be supported, without mutual electronic interference, than would ever be possible with circular orbits.

  16. Results of Satellite Brightness Modeling Using Kringing Optimized Interpolation

    Science.gov (United States)

    Weeden, C.; Hejduk, M.

    At the 2005 AMOS conference, Kriging Optimized Interpolation (KOI) was presented as a tool to model satellite brightness as a function of phase angle and solar declination angle (J.M Okada and M.D. Hejduk). Since November 2005, this method has been used to support the tasking algorithm for all optical sensors in the Space Surveillance Network (SSN). The satellite brightness maps generated by the KOI program are compared to each sensor's ability to detect an object as a function of the brightness of the background sky and angular rate of the object. This will determine if the sensor can technically detect an object based on an explicit calculation of the object's probability of detection. In addition, recent upgrades at Ground-Based Electro Optical Deep Space Surveillance Sites (GEODSS) sites have increased the amount and quality of brightness data collected and therefore available for analysis. This in turn has provided enough data to study the modeling process in more detail in order to obtain the most accurate brightness prediction of satellites. Analysis of two years of brightness data gathered from optical sensors and modeled via KOI solutions are outlined in this paper. By comparison, geo-stationary objects (GEO) were tracked less than non-GEO objects but had higher density tracking in phase angle due to artifices of scheduling. A statistically-significant fit to a deterministic model was possible less than half the time in both GEO and non-GEO tracks, showing that a stochastic model must often be used alone to produce brightness results, but such results are nonetheless serviceable. Within the Kriging solution, the exponential variogram model was the most frequently employed in both GEO and non-GEO tracks, indicating that monotonic brightness variation with both phase and solar declination angle is common and testifying to the suitability to the application of regionalized variable theory to this particular problem. Finally, the average nugget value, or

  17. Instrumental Genesis in GeoGebra Based Board Game Design

    DEFF Research Database (Denmark)

    Misfeldt, Morten

    2013-01-01

    In this paper I address the use of digital tools (GeoGebra) in open ended design activities, with primary school children. I present results from the research and development project “Creative Digital Mathematics”, which aims to use the pupil’s development of mathematical board games as a vehicle...... in their work with GeoGebra and how they relate their work with GeoGebra and mathematics to fellow pupils and real life situations. The results show that pupils’ consider development of board games as meaningful mathematical activity, and that they develop skills with GeoGebra, furthermore the pupils considers...

  18. Satellite Communications

    CERN Document Server

    Pelton, Joseph N

    2012-01-01

    The field of satellite communications represents the world's largest space industry. Those who are interested in space need to understand the fundamentals of satellite communications, its technology, operation, business, economic, and regulatory aspects. This book explains all this along with key insights into the field's future growth trends and current strategic challenges. Fundamentals of Satellite Communications is a concise book that gives all of the key facts and figures as well as a strategic view of where this dynamic industry is going. Author Joseph N. Pelton, PhD, former Dean of the International Space University and former Director of Strategic Policy at Intelstat, presents a r

  19. Geo energy research and development: technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Traeger, R.K.

    1982-03-01

    Sandia Geo Energy Programs related to geothermal, coal, oil and gas, and synfuel resources have provided a useful mechanism for transferring laboratory technologies to private industry. Significant transfer of hardware, computer programs, diagnostics and instrumentation, advanced materials, and in situ process understanding has occurred through US/DOE supported programs in the past five years. The text briefly reviews the technology transfer procedures and summarizes 32 items that have been transferred and another 20 technologies that are now being considered for possible transfer to industry. A major factor in successful transfer has been personal interactions between Sandia engineers and the technical staff from private industry during all aspects of the technology development.

  20. Effect of Ionosphere on Geostationary Communication Satellite Signals

    Science.gov (United States)

    Erdem, Esra; Arikan, Feza; Gulgonul, Senol

    2016-07-01

    Geostationary orbit (GEO) communications satellites allow radio, television, and telephone transmissions to be sent live anywhere in the world. They are extremely important in daily life and also for military applications. Since, satellite communication is an expensive technology addressing crowd of people, it is critical to improve the performance of this technology. GEO satellites are at 35,786 kilometres from Earth's surface situated directly over the equator. A satellite in a geostationary orbit (GEO) appears to stand still in the sky, in a fixed position with respect to an observer on the earth, because the satellite's orbital period is the same as the rotation rate of the Earth. The advantage of this orbit is that ground antennas can be fixed to point towards to satellite without their having to track the satellite's motion. Radio frequency ranges used in satellite communications are C, X, Ku, Ka and even EHG and V-band. Satellite signals are disturbed by atmospheric effects on the path between the satellite and the receiver antenna. These effects are mostly rain, cloud and gaseous attenuation. It is expected that ionosphere has a minor effect on the satellite signals when the ionosphere is quiet. But there are anomalies and perturbations on the structure of ionosphere with respect to geomagnetic field and solar activity and these conditions may cause further affects on the satellite signals. In this study IONOLAB-RAY algorithm is adopted to examine the effect of ionosphere on satellite signals. IONOLAB-RAY is developed to calculate propagation path and characteristics of high frequency signals. The algorithm does not have any frequency limitation and models the plasmasphere up to 20,200 km altitude, so that propagation between a GEO satellite and antenna on Earth can be simulated. The algorithm models inhomogeneous, anisotropic and time dependent structure of the ionosphere with a 3-D spherical grid geometry and calculates physical parameters of the

  1. Use of a geosynchronous satellite within the SARSAT/COSPAS system

    Science.gov (United States)

    Goudy, P.; Ludwig, D.; Trudell, B.

    1982-01-01

    Operational characteristics of combined LEO SARSAT/COSPAS and GEO spacecraft for localization of aircraft and seacraft emitting distress signals are described. Although 121.5 MHz capability is now included in all SARSAT/COSPAS satellites, limitations on the number of simultaneous signals which can be processed at that frequency due to atmospheric noise indicates the employment of the 406 MHz band. Additionally, the necessity for on-board storage for later transmission when the satellites are in a favorable position is leading to the implementation of GEO stationed relays for real-time transmission and processing of distress signals. Six NOAA spacecraft and two Soviet satellites are planned, with a completed system offering high detection probability, position location, worldwide coverage, coded messages, and high capacity (406 MHz). A significant factor in use of a GEO relay system is noted to be the signal to noise temperature of the repeater.

  2. Satellite Geomagnetism

    DEFF Research Database (Denmark)

    Olsen, Nils; Stolle, Claudia

    2012-01-01

    Observations of Earth’s magnetic field from space began more than 50 years ago. A continuous monitoring of the field using low Earth orbit (LEO) satellites, however, started only in 1999, and three satellites have taken highprecision measurements of the geomagnetic field during the past decade...... ability to characterize and understand the many sources that contribute to Earth’s magnetic field. In this review, we summarize investigations of Earth’s interior and environment that have been possible through the analysis of high-precision magnetic field observations taken by LEO satellites........ The unprecedented time-space coverage of their data opened revolutionary new possibilities for monitoring, understanding, and exploring Earth’s magnetic field. In the near future, the three-satellite constellation Swarm will ensure continuity of such measurement and provide enhanced possibilities to improve our...

  3. Satellite (Natural)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    In its most general sense, any celestial object in orbit around a similar larger object. Thus, for example, the Magellanic Clouds are satellite galaxies of our own Milky Way galaxy. Without qualification, the term is used to mean a body in orbit around a planet; an alternative term is moon. The term natural satellite distinguishes these bodies from artificial satellites—spacecraft placed in orbi...

  4. Satellite Ocean Biology: Past, Present, Future

    Science.gov (United States)

    McClain, Charles R.

    2012-01-01

    Since 1978 when the first satellite ocean color proof-of-concept sensor, the Nimbus-7 Coastal Zone Color Scanner, was launched, much progress has been made in refining the basic measurement concept and expanding the research applications of global satellite time series of biological and optical properties such as chlorophyll-a concentrations. The seminar will review the fundamentals of satellite ocean color measurements (sensor design considerations, on-orbit calibration, atmospheric corrections, and bio-optical algorithms), scientific results from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and Moderate resolution Imaging Spectroradiometer (MODIS) missions, and the goals of future NASA missions such as PACE, the Aerosol, Cloud, Ecology (ACE), and Geostationary Coastal and Air Pollution Events (GeoCAPE) missions.

  5. GENERAL EARTHQUAKE-OBSERVATION SYSTEM (GEOS).

    Science.gov (United States)

    Borcherdt, R.D.; Fletcher, Joe B.; Jensen, E.G.; Maxwell, G.L.; VanSchaack, J.R.; Warrick, R.E.; Cranswick, E.; Johnston, M.J.S.; McClearn, R.

    1985-01-01

    Microprocessor technology has permitted the development of a General Earthquake-Observation System (GEOS) useful for most seismic applications. Central-processing-unit control via robust software of system functions that are isolated on hardware modules permits field adaptability of the system to a wide variety of active and passive seismic experiments and straightforward modification for incorporation of improvements in technology. Various laboratory tests and numerous deployments of a set of the systems in the field have confirmed design goals, including: wide linear dynamic range (16 bit/96 dB); broad bandwidth (36 hr to 600 Hz; greater than 36 hr available); selectable sensor-type (accelerometer, seismometer, dilatometer); selectable channels (1 to 6); selectable record mode (continuous, preset, trigger); large data capacity (1. 4 to 60 Mbytes); selectable time standard (WWVB, master, manual); automatic self-calibration; simple field operation; full capability to adapt system in the field to a wide variety of experiments; low power; portability; and modest costs. System design goals for a microcomputer-controlled system with modular software and hardware components as implemented on the GEOS are presented. The systems have been deployed for 15 experiments, including: studies of near-source strong motion; high-frequency microearthquakes; crustal structure; down-hole wave propagation; teleseismicity; and earth-tidal strains.

  6. GEO600 Online Detector Characterization System

    CERN Document Server

    Balasubramanian, R; Churches, D; Cokelaer, T

    2005-01-01

    A world-wide network of interferometric gravitational wave detectors is currently operational. The detectors in the network are still in their commissioning phase and are expected to achieve their design sensitivity over the next year or so. Each detector is a complex instrument involving many subsystems and each subsystem is a source of noise at the output of the detector. Therefore, in addition to recording the main gravitational wave data channel at the output of the interferometer, the state of each detector subsystem is monitored and recorded. This subsidiary data is both large in volume as well as complex in nature. We require an online monitoring and analysis tool which can process all the data channels for various noise artefacts and summarize the results of the analysis in a manner that can be accessed and interpreted conveniently. In this paper we describe the GEO600 Online Detector Characterization System (GODCS), which is the tool that is being used to monitor the output of the GEO600 gravitationa...

  7. Making the Case for GeoSTEM Education

    Science.gov (United States)

    Moore, John

    2014-05-01

    -related resources that monitor our planet and protect the life and property of our citizens. The integration of a Geoscience and Remote Sensing Laboratory into an existing Earth Science program or a new Earth Systems Science course allows students to acquire the necessary rigorous laboratory skills as required by colleges or universities, while developing and becoming proficient in technological skills using industry standard analysis tools. With the accessibility of real-time or near real time data, students in a GeoSTEM driven course can engage in inquiry-based laboratory experiences focusing on real life applications, both local and global. Developing pathways between geoscientists, researchers, teachers, and students, will create an exchange of information, data, observations, and measurements that will lead to authentic science investigations through the monitoring of weather, water quality, sea surface temperature, coral reefs, marine wildlife, earthquakes, tsunamis, wildfires, air quality, land cover, and much more. Satellite, remote sensing, and geospatial technologies can introduce students and society to data that can inform policy makers and society both now and in the future.

  8. Geo-locked photo sharing on mobile devices

    NARCIS (Netherlands)

    Vyas, Dhaval; Keijl, Edwin; Akker, op den Rieks; Nijholt, Anton; Veer, van der Gerrit

    2013-01-01

    We introduce the idea of geo-locking through a mobile phone based photo sharing application called Picalilly. Using its geo-locking feature, Picalilly allows its users to manually define geographical boundaries for sharing photos – limiting sharing within user-defined boundaries as well as facilitat

  9. Model-driven design of geo-information services

    NARCIS (Netherlands)

    Morales Guarin, J.M.; Morales Guarin, Javier Marcelino

    2004-01-01

    This thesis presents a method for the development of distributed geo-information systems. The method is organised around the design principles of modularity, reuse and replaceability. The method enables the modelling of both behavioural and informational aspects of geo-information systems in an inte

  10. The economic value of the Dutch geo-information sector

    NARCIS (Netherlands)

    Castelein, W.T.; Bregt, A.K.; Pluijmers, Y.

    2010-01-01

    Defining the geo-information sector and estimating its economic value on a national level is difficult and standard methodologies are not available. The aim of this paper is to clearly define the geo-information sector and to measure its economic value in terms of turnover, employment, activities an

  11. Report literature research geo-visualization and participatory spatial planning

    NARCIS (Netherlands)

    Bloemmen, M.H.I.; Fransen, H.; Hoogerwerf, T.C.; Ligtenberg, A.; Lammeren, van R.J.A.

    2005-01-01

    The use of geo-visualization for participatory planning purposes is a challenging field of research. Reason for this is that researchers involved with the subject currently lack a common rationale for the integration of the two complementary domains: participatory planning and geo-visualization. Con

  12. The economic value of the Dutch geo-information sector

    NARCIS (Netherlands)

    Castelein, W.T.; Bregt, A.K.; Pluijmers, Y.

    2010-01-01

    Defining the geo-information sector and estimating its economic value on a national level is difficult and standard methodologies are not available. The aim of this paper is to clearly define the geo-information sector and to measure its economic value in terms of turnover, employment, activities

  13. Model-driven design of geo-information services

    NARCIS (Netherlands)

    Morales Guarin, Javier Marcelino

    2004-01-01

    This thesis presents a method for the development of distributed geo-information systems. The method is organised around the design principles of modularity, reuse and replaceability. The method enables the modelling of both behavioural and informational aspects of geo-information systems in an inte

  14. Report literature research geo-visualization and participatory spatial planning

    NARCIS (Netherlands)

    Bloemmen, M.H.I.; Fransen, H.; Hoogerwerf, T.C.; Ligtenberg, A.; Lammeren, van R.J.A.

    2005-01-01

    The use of geo-visualization for participatory planning purposes is a challenging field of research. Reason for this is that researchers involved with the subject currently lack a common rationale for the integration of the two complementary domains: participatory planning and geo-visualization. Con

  15. Making Room: Integrating Geo-Technologies into Teacher Education

    Science.gov (United States)

    Gatrell, Jay D.

    2004-01-01

    Geo-educators focus on content standards, particularly the 1994 "Geography for Life" standards, as the primary rationale for integrating geo-spatial technologies into preservice teacher education programs. In this paper, an alternative framework is proposed to infuse GIS and GIScience into existing teacher education programs. Specifically, the…

  16. An enhanced algorithm to estimate BDS satellite's differential code biases

    Science.gov (United States)

    Shi, Chuang; Fan, Lei; Li, Min; Liu, Zhizhao; Gu, Shengfeng; Zhong, Shiming; Song, Weiwei

    2016-02-01

    This paper proposes an enhanced algorithm to estimate the differential code biases (DCB) on three frequencies of the BeiDou Navigation Satellite System (BDS) satellites. By forming ionospheric observables derived from uncombined precise point positioning and geometry-free linear combination of phase-smoothed range, satellite DCBs are determined together with ionospheric delay that is modeled at each individual station. Specifically, the DCB and ionospheric delay are estimated in a weighted least-squares estimator by considering the precision of ionospheric observables, and a misclosure constraint for different types of satellite DCBs is introduced. This algorithm was tested by GNSS data collected in November and December 2013 from 29 stations of Multi-GNSS Experiment (MGEX) and BeiDou Experimental Tracking Stations. Results show that the proposed algorithm is able to precisely estimate BDS satellite DCBs, where the mean value of day-to-day scattering is about 0.19 ns and the RMS of the difference with respect to MGEX DCB products is about 0.24 ns. In order to make comparison, an existing algorithm based on IGG: Institute of Geodesy and Geophysics, China (IGGDCB), is also used to process the same dataset. Results show that, the DCB difference between results from the enhanced algorithm and the DCB products from Center for Orbit Determination in Europe (CODE) and MGEX is reduced in average by 46 % for GPS satellites and 14 % for BDS satellites, when compared with DCB difference between the results of IGGDCB algorithm and the DCB products from CODE and MGEX. In addition, we find the day-to-day scattering of BDS IGSO satellites is obviously lower than that of GEO and MEO satellites, and a significant bias exists in daily DCB values of GEO satellites comparing with MGEX DCB product. This proposed algorithm also provides a new approach to estimate the satellite DCBs of multiple GNSS systems.

  17. Precise Orbit Determination of BeiDou Satellites with Contributions from Chinese National Continuous Operating Reference Stations

    Directory of Open Access Journals (Sweden)

    Ming Chen

    2017-08-01

    Full Text Available The precise orbit determination (POD for BeiDou satellites is usually limited by the insufficient quantity and poor distribution of ground tracking stations. To cope with this problem, this study used the GPS and BeiDou joint POD method based on Chinese national continuous operating reference stations (CNCORS and IGS/MGEX stations. The results show that the 3D RMS of the differences of overlapping arcs is better than 22 cm for geostationary orbit (GEO satellites and better than 10 cm for inclined geosynchronous orbit (IGSO and medium earth orbit (MEO satellites. The radial RMS is better than 2 cm for all three types of BeiDou satellites. The results of satellite laser ranging (SLR residuals show that the RMS of the IGSO and MEO satellites is better than 5 cm, whereas the GEO satellite has a systematic bias. This study investigates the contributions of CNCORS to the POD of BeiDou satellites. The results show that after the incorporation of CNCORS, the precision of overlapping arcs of the GEO, IGSO, and MEO satellites is improved by 15.5%, 57.5%, and 5.3%, respectively. In accordance with the improvement in the precision of overlapping arcs, the accuracy of the IGSO and MEO satellites assessed by the SLR is improved by 30.1% and 4.8%, respectively. The computation results and analysis demonstrate that the inclusion of CNCORS yields the biggest contribution in the improvement of orbit accuracy for IGSO satellites, when compared to GEO satellites, while the orbit improvement for MEO satellites is the lowest due to their global coverage.

  18. The Small Size Debris Population at GEO from Optical Observations

    Science.gov (United States)

    Seitzer, Patrick; Barker, Ed; Buckalew, Brent; Burkhardt, Andrew; Cowardin, Heather; Frith, James; Kaleida, Catherine; Lederer, Susan M.; Lee, Chris H.

    2017-01-01

    We have observed the geosynchronous orbit (GEO) debris population at sizes smaller than 10 cm using optical observations with the 6.5-m Magellan telescope 'Walter Baade' at the Las Campanas Observatory in Chile. The IMACS f/2 imaging camera with a 0.5-degree diameter field of view has been used in small area surveys of the GEO regime to study the population of optically faint GEO debris. The goal is to estimate the population of GEO debris that is fainter than can be studied with 1-meter class telescopes. A significant population of objects fainter than R = 19th magnitude has been found. These objects have observed with angular rates consistent with circular orbits and orbital inclinations up to 15 degrees at GEO. A sizeable number of these objects have significant brightness variations ("flashes") during the 5-second exposure, which suggest rapid changes in the albedo-projected size product.

  19. Paradigm shift from cartography to geo-communication

    DEFF Research Database (Denmark)

    Brodersen, Lars

    2007-01-01

    -defined to be a communication discipline. The major argument for this position is that no information is ever recorded and stored just for its own purpose. There is always the purpose that any type of geo-information is recorded and stored for usage by someone. Always! Identification and registration of geo......-information is actually not possible at all without having a usage (a project identity and a purpose) in mind. Objective and neutral geo-information does not exist. Therefore the overall philosophy of the geo-domain will be that it is a communication discipline.......This paper argues that the domain of GIS, cartography, geo-information etc. is facing a paradigm shift. The implication of a paradigm shift is a complete and necessary re-definition of e.g. the philosophical foundation of the system, as well as with a major upgrade and readjustment of procedures...

  20. Geo-communication and Web-based Spatial Data Infrastructure

    DEFF Research Database (Denmark)

    Brodersen, Lars; Nielsen, Anders

    2006-01-01

    ! Therefore there is a strong need for theories and models that can describe this complex web in the SDI and geo-communication consisting of active components, passive components, users and information in order to make it possible to handle the complexity and to give the necessary framework.......The purpose of geo-communication is to bridge the gap between reality and data sources on one side and decisions on the other side. This is achieved through several types of activities, where web-services and spatial data infrastructure play an important role. The introduction of web......-services as index-portals based on geo-information has changed the conditions for both content and form of geo-communication. A high number of players and interactions as well as a very high number of all kinds of information and combinations of these characterize geo-communication carried out through web...

  1. Geo-communication, web-services, and spatial data infrastructure

    DEFF Research Database (Denmark)

    Brodersen, Lars; Nielsen, Anders

    2007-01-01

    The introduction of web-services as index-portals based on geo-information has changed the conditions for both content and form of geo-communication. A high number of players and interactions as well as a very high number of all kinds of information and combinations of these caracterise web...... looks very complex, and it will get even more complex. Therefore, there is a strong need for theories and models that can describe this complex web in the SDI and geo-communication consisting of active components, passive components, users, and information in order to make it possible to handle......, collaboration, standards, models, specifications, web services, and finally the information. Awareness of the complexity is necessary, and structure is needed to make it possible for the geo-information community to pull together in the same direction. Modern web-based geo-communication and its infrastucture...

  2. Geo-communication, web-services, and spatial data infrastructure

    DEFF Research Database (Denmark)

    Brodersen, Lars; Nielsen, Anders

    2007-01-01

    The introduction of web-services as index-portals based on geo-information has changed the conditions for both content and form of geo-communication. A high number of players and interactions as well as a very high number of all kinds of information and combinations of these caracterise web...... services, where maps are only a part of the whole. This chapter discusses the relations between the different components of SDI and geo-communication as well as the impact thereof. Discussed is also a model for the organization of the passive components of the infrastructure; that is, legislation......, collaboration, standards, models, specifications, web services, and finally the information. Awareness of the complexity is necessary, and structure is needed to make it possible for the geo-information community to pull together in the same direction. Modern web-based geo-communication and its infrastucture...

  3. Preserving Location and Absence Privacy in Geo-Social Networks

    DEFF Research Database (Denmark)

    Freni, Dario; Vicente, Carmen Ruiz; Mascetti, Sergio

    2010-01-01

    . The resulting geo-aware social networks (GeoSNs) pose privacy threats beyond those found in location-based services. Con- tent published in a GeoSN is often associated with references to multiple users, without the publisher being aware of the privacy preferences of those users. Moreover, this content is often...... accessible to multiple users. This renders it dicult for GeoSN users to control which information about them is available and to whom it is available. This paper addresses two privacy threats that occur in GeoSNs: location privacy and absence privacy. The former concerns the availability of information about...... the presence of users in specic locations at given times, while the latter concerns the availability of information about the absence of an individual from spe- cic locations during given periods of time. The challenge addressed is that of supporting privacy while still enabling useful services. We believe...

  4. Instrumental Genesis in GeoGebra Based Board Game Design

    DEFF Research Database (Denmark)

    Misfeldt, Morten

    2013-01-01

    for teaching skills with GeoGebra, as well as an entrepreneurial attitude towards mathematics. Using the instrumental approach I discuss how open ended transdisciplinary design activities can support instrumental genesis, by considering the extent to which the pupils address mathematical knowledge......In this paper I address the use of digital tools (GeoGebra) in open ended design activities, with primary school children. I present results from the research and development project “Creative Digital Mathematics”, which aims to use the pupil’s development of mathematical board games as a vehicle...... in their work with GeoGebra and how they relate their work with GeoGebra and mathematics to fellow pupils and real life situations. The results show that pupils’ consider development of board games as meaningful mathematical activity, and that they develop skills with GeoGebra, furthermore the pupils considers...

  5. NCBI GEO: archive for functional genomics data sets--update.

    Science.gov (United States)

    Barrett, Tanya; Wilhite, Stephen E; Ledoux, Pierre; Evangelista, Carlos; Kim, Irene F; Tomashevsky, Maxim; Marshall, Kimberly A; Phillippy, Katherine H; Sherman, Patti M; Holko, Michelle; Yefanov, Andrey; Lee, Hyeseung; Zhang, Naigong; Robertson, Cynthia L; Serova, Nadezhda; Davis, Sean; Soboleva, Alexandra

    2013-01-01

    The Gene Expression Omnibus (GEO, http://www.ncbi.nlm.nih.gov/geo/) is an international public repository for high-throughput microarray and next-generation sequence functional genomic data sets submitted by the research community. The resource supports archiving of raw data, processed data and metadata which are indexed, cross-linked and searchable. All data are freely available for download in a variety of formats. GEO also provides several web-based tools and strategies to assist users to query, analyse and visualize data. This article reports current status and recent database developments, including the release of GEO2R, an R-based web application that helps users analyse GEO data.

  6. Estimation of Satellite PCO Offsets for BeiDou based on MGEX Net Solution

    Science.gov (United States)

    Yize, Zhang; Junping, Chen; Bin, Wu; Jiexian, Wang

    2015-04-01

    BeiDou Satellite Navigation System currently has a total 14 satellites including GEO/IGSO/MEO satellites and providing a regional PNT service. Due to a lack of publicly available antenna phase center offsets (PCO) for the BeiDou satellites, conventional values of (+0.6 m, 0.0 m, +1.1 m) are recommended for orbit and clock determination of the GEO/IGSO/MEO satellites, which needs to be further estimation and refinement. In this paper, we propose a multi-GNSS network solution for the estimation of BeiDou satellite PCO. More than 35 ground stations of International GNSS MGEX tracking network are used to determine the BeiDou satellite PCO. In this strategy, the GPS and BeiDou satellite orbits and clocks are derived from IGS final products, and GPS satellite PCO and PCV are fixed according to igs08.atx. The BeiDou satellites PCO are estimated together with the station clock, troposphere delay and LC combination ambiguity parameter. Result shows that the RMS of phase residuals for all stations is 1.8cm and is 1.6m for code residual, respectively. The estimated PCO is different for each satellite. Appling the new PCO for precise point positioning, we found that the positioning error improves from 6cm to 2cm in height.

  7. Optical Reflection Spectroscopy of GEO Objects

    Science.gov (United States)

    Seitzer, Patrick; Cardona, Tammaso; Lederer, Susan M.; Cowardin, Heather; Abercromby, Kira J.; Barker, Edwin S.; Bedard, Donald

    2013-01-01

    We report on optical reflection spectroscopy of geosynchronous (GEO) objects in the US Space Surveillance Network (SSN) catalog. These observations were obtained using imaging spectrographs on the 6.5-m Magellan telescopes at the Las Campanas Observatory in Chile. Our goal is to determine the composition of these objects by comparing these spectral observations with ground-based laboratory measurements of spacecraft materials. The observations are all low resolution (1 nm after smoothing) obtained through a 5 arcsecond wide slit and using a grism as the dispersing element. The spectral range covered was from 450 nm to 800 nm. All spectra were flux calibrated using observations of standard stars with the exact same instrumental setup. An effort was made to obtain all observations within a limited range of topocentric phase angle, although the solar incident angle is unknown due to the lack of any knowledge of the attitude of the observed surface at the time of observation.

  8. 3D GEO: AN ALTERNATIVE APPROACH

    Directory of Open Access Journals (Sweden)

    A. Georgopoulos

    2016-10-01

    Full Text Available The expression GEO is mostly used to denote relation to the earth. However it should not be confined to what is related to the earth's surface, as other objects also need three dimensional representation and documentation, like cultural heritage objects. They include both tangible and intangible ones. In this paper the 3D data acquisition and 3D modelling of cultural heritage assets are briefly described and their significance is also highlighted. Moreover the organization of such information, related to monuments and artefacts, into relational data bases and its use for various purposes, other than just geometric documentation is also described and presented. In order to help the reader understand the above, several characteristic examples are presented and their methodology explained and their results evaluated.

  9. 3D Geo: An Alternative Approach

    Science.gov (United States)

    Georgopoulos, A.

    2016-10-01

    The expression GEO is mostly used to denote relation to the earth. However it should not be confined to what is related to the earth's surface, as other objects also need three dimensional representation and documentation, like cultural heritage objects. They include both tangible and intangible ones. In this paper the 3D data acquisition and 3D modelling of cultural heritage assets are briefly described and their significance is also highlighted. Moreover the organization of such information, related to monuments and artefacts, into relational data bases and its use for various purposes, other than just geometric documentation is also described and presented. In order to help the reader understand the above, several characteristic examples are presented and their methodology explained and their results evaluated.

  10. Scientific Satellites

    Science.gov (United States)

    1967-01-01

    followed Hale’s into orbit. In 1879, Jules Verne wrote about launching small satellites with a gun possessing a muzzle velocity of 10 000 m/sec (ref. 3...was activated in 1950.11 It was located only a few tens of miles from the spot where Jules Verne had his Baltimore Gun Club fire a manned projectile to...principle, satellites can be launched by a single impulse applied at the Earth’s surface-say, with a large cannon, & la Jules Verne (sec. 8-3). In

  11. Foucault's geo-epistemology: Geography, spaces, places

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    Dušan Marinković

    2014-12-01

    Full Text Available The paper discusses Foucault’s “spatial turn” which represented a very firm criticism of the western historical thought. By introducing “new” spatial metaphors or dispositives in the restoring Foucauldian discourse, through the concept of geo-epistemology, we identify the significance of this turn. Geo-epistemology simultaneously represents the analysis of knowledge and discourses which are formed through spaces and the analysis of space formed through knowledge/power/discourses. Of many spatial metaphors that Foucault used in almost his entire opus we single out the metaphor of the scenography of space/dramaturgy of scenes, which reflects well Foucault’s usual starting points of the analysis which he used to indicate points of break and transformation: of discourses, established practices, their effects, ritual regularities and implementations, their relationships – towards bodies, population, the diseased, prisoners, people on the margins, abnormal people. The paper names examples of discourses and practices that Foucault researched in order to demonstrate that the subjects of his analysis always had their spatialized forms, their geography, their archaeology, history, and a Nietzschean type of genealogy, i.e. spaces where they were placed and in which their speeches or technologies were distributed. The paper also discusses Foucault’s “heterotopic geography” which was only seemingly reactionary and conservative in its relinquishing of dialectal sources of a totalizing history. In the conclusion the paper stresses that, unlike Neo-Marxist responses to the hegemony of a temporal narrative, Foucault’s research of space had much more far-reaching consequences: an epistemological transformation of space and other basic geographic concepts.

  12. GeoChronos: An On-line Collaborative Platform for Earth Observation Scientists

    Science.gov (United States)

    Gamon, J. A.; Kiddle, C.; Curry, R.; Markatchev, N.; Zonta-Pastorello, G., Jr.; Rivard, B.; Sanchez-Azofeifa, G. A.; Simmonds, R.; Tan, T.

    2009-12-01

    Recent advances in cyberinfrastructure are offering new solutions to the growing challenges of managing and sharing large data volumes. Web 2.0 and social networking technologies, provide the means for scientists to collaborate and share information more effectively. Cloud computing technologies can provide scientists with transparent and on-demand access to applications served over the Internet in a dynamic and scalable manner. Semantic Web technologies allow for data to be linked together in a manner understandable by machines, enabling greater automation. Combining all of these technologies together can enable the creation of very powerful platforms. GeoChronos (http://geochronos.org/), part of a CANARIE Network Enabled Platforms project, is an online collaborative platform that incorporates these technologies to enable members of the earth observation science community to share data and scientific applications and to collaborate more effectively. The GeoChronos portal is built on an open source social networking platform called Elgg. Elgg provides a full set of social networking functionalities similar to Facebook including blogs, tags, media/document sharing, wikis, friends/contacts, groups, discussions, message boards, calendars, status, activity feeds and more. An underlying cloud computing infrastructure enables scientists to access dynamically provisioned applications via the portal for visualizing and analyzing data. Users are able to access and run the applications from any computer that has a Web browser and Internet connectivity and do not need to manage and maintain the applications themselves. Semantic Web Technologies, such as the Resource Description Framework (RDF) are being employed for relating and linking together spectral, satellite, meteorological and other data. Social networking functionality plays an integral part in facilitating the sharing of data and applications. Examples of recent GeoChronos users during the early testing phase have

  13. Analysis of BeiDou Satellite Measurements with Code Multipath and Geometry-Free Ionosphere-Free Combinations.

    Science.gov (United States)

    Zhao, Qile; Wang, Guangxing; Liu, Zhizhao; Hu, Zhigang; Dai, Zhiqiang; Liu, Jingnan

    2016-01-20

    Using GNSS observable from some stations in the Asia-Pacific area, the carrier-to-noise ratio (CNR) and multipath combinations of BeiDou Navigation Satellite System (BDS), as well as their variations with time and/or elevation were investigated and compared with those of GPS and Galileo. Provided the same elevation, the CNR of B1 observables is the lowest among the three BDS frequencies, while B3 is the highest. The code multipath combinations of BDS inclined geosynchronous orbit (IGSO) and medium Earth orbit (MEO) satellites are remarkably correlated with elevation, and the systematic "V" shape trends could be eliminated through between-station-differencing or modeling correction. Daily periodicity was found in the geometry-free ionosphere-free (GFIF) combinations of both BDS geostationary Earth orbit (GEO) and IGSO satellites. The variation range of carrier phase GFIF combinations of GEO satellites is -2.0 to 2.0 cm. The periodicity of carrier phase GFIF combination could be significantly mitigated through between-station differencing. Carrier phase GFIF combinations of BDS GEO and IGSO satellites might also contain delays related to satellites. Cross-correlation suggests that the GFIF combinations' time series of some GEO satellites might vary according to their relative geometries with the sun.

  14. Analysis of BeiDou Satellite Measurements with Code Multipath and Geometry-Free Ionosphere-Free Combinations

    Directory of Open Access Journals (Sweden)

    Qile Zhao

    2016-01-01

    Full Text Available Using GNSS observable from some stations in the Asia-Pacific area, the carrier-to-noise ratio (CNR and multipath combinations of BeiDou Navigation Satellite System (BDS, as well as their variations with time and/or elevation were investigated and compared with those of GPS and Galileo. Provided the same elevation, the CNR of B1 observables is the lowest among the three BDS frequencies, while B3 is the highest. The code multipath combinations of BDS inclined geosynchronous orbit (IGSO and medium Earth orbit (MEO satellites are remarkably correlated with elevation, and the systematic “V” shape trends could be eliminated through between-station-differencing or modeling correction. Daily periodicity was found in the geometry-free ionosphere-free (GFIF combinations of both BDS geostationary Earth orbit (GEO and IGSO satellites. The variation range of carrier phase GFIF combinations of GEO satellites is −2.0 to 2.0 cm. The periodicity of carrier phase GFIF combination could be significantly mitigated through between-station differencing. Carrier phase GFIF combinations of BDS GEO and IGSO satellites might also contain delays related to satellites. Cross-correlation suggests that the GFIF combinations’ time series of some GEO satellites might vary according to their relative geometries with the sun.

  15. Space Solar Power Satellite Systems, Modern Small Satellites, and Space Rectenna

    Science.gov (United States)

    Bergsrud, Corey Alexis Marvin

    Space solar power satellite (SSPS) systems is the concept of placing large satellite into geostationary Earth orbit (GEO) to harvest and convert massive amounts of solar energy into microwave energy, and to transmit the microwaves to a rectifying antenna (rectenna) array on Earth. The rectenna array captures and converts the microwave power into usable power that is injected into the terrestrial electric grid for use. This work approached the microwave power beam as an additional source of power (with solar) for lower orbiting satellites. Assuming the concept of retrodirectivity, a GEO-SSPS antenna array system tracks and delivers microwave power to lower orbiting satellites. The lower orbiting satellites are equipped with a stacked photovoltaic (PV)/rectenna array hybrid power generation unit (HPGU) in order to harvest solar and/or microwave energy for on-board use during orbit. The area, and mass of the PV array part of the HPGU was reduced at about 32% beginning-of-life power in order to achieve the spacecraft power requirements. The HPGU proved to offer a mass decrease in the PGU, and an increase in mission life due to longer living component life of the rectenna array. Moreover, greater mission flexibility is achieved through a track and power delivery concept. To validate the potential advantages offered by a HPGU, a mission concept was presented that utilizes modern small satellites as technology demonstrators. During launch, a smaller power receiving "daughter" satellite sits inside a larger power transmitting "mother" satellite. Once separated from the launch vehicle the daughter satellite is ejected away from the mother satellite, and each satellite deploys its respective power transmitting or power receiving hardware's for experimentation. The concept of close proximity mission operations between the satellites is considered. To validate the technology of the space rectenna array part of the HPGU, six milestones were completed in the design. The first

  16. Analyzing Forest Inventory Data from Geo-Located Photographs

    Science.gov (United States)

    Toivanen, Timo; Tergujeff, Renne; Andersson, Kaj; Molinier, Matthieu; Häme, Tuomas

    2015-04-01

    Forests are widely monitored using a variety of remote sensing data and techniques. Remote sensing offers benefits compared to traditional in-situ forest inventories made by experts. One of the main benefits is that the number of ground reference plots can be significantly reduced. Remote sensing of forests can provide reduced costs and time requirement compared to full forest inventories. The availability of ground reference data has been a bottleneck in remote sensing analysis over wide forested areas, as the acquisition of this data is an expensive and slow process. In this paper we present a tool for estimating forest inventory data from geo-located photographs. The tool can be used to estimate in-situ forest inventory data including estimated biomass, tree species, tree height and diameter. The collected in-situ forest measurements can be utilized as a ground reference material for spaceborne or airborne remote sensing data analysis. The GPS based location information with measured forest data makes it possible to introduce measurements easily as in-situ reference data. The central projection geometry of digital photographs allows the use of the relascope principle [1] to measure the basal area of stems per area unit, a variable very closely associated with tree biomass. Relascope is applied all over the world for forest inventory. Experiments with independent ground reference data have shown that in-situ data analysed from photographs can be utilised as reference data for satellite image analysis. The concept was validated by comparing mobile measurements with 54 independent ground reference plots from the Hyytiälä forest research station in Finland [2]. Citizen scientists could provide the manpower for analysing photographs from forests on a global level and support researchers working on tasks related to forests. This low-cost solution can also increase the coverage of forest management plans, particularly in regions where possibilities to invest on

  17. Coarse Initial Orbit Determination for a Geostationary Satellite Using Single-Epoch GPS Measurements

    Directory of Open Access Journals (Sweden)

    Ghangho Kim

    2015-04-01

    Full Text Available A practical algorithm is proposed for determining the orbit of a geostationary orbit (GEO satellite using single-epoch measurements from a Global Positioning System (GPS receiver under the sparse visibility of the GPS satellites. The algorithm uses three components of a state vector to determine the satellite’s state, even when it is impossible to apply the classical single-point solutions (SPS. Through consideration of the characteristics of the GEO orbital elements and GPS measurements, the components of the state vector are reduced to three. However, the algorithm remains sufficiently accurate for a GEO satellite. The developed algorithm was tested on simulated measurements from two or three GPS satellites, and the calculated maximum position error was found to be less than approximately 40 km or even several kilometers within the geometric range, even when the classical SPS solution was unattainable. In addition, extended Kalman filter (EKF tests of a GEO satellite with the estimated initial state were performed to validate the algorithm. In the EKF, a reliable dynamic model was adapted to reduce the probability of divergence that can be caused by large errors in the initial state.

  18. Building web service interfaces to geoscience data sets: EarthCube GeoWS project activities at the IRIS DMC

    Science.gov (United States)

    Trabant, C. M.; Ahern, T. K.; Stults, M.

    2015-12-01

    At the IRIS Data Management Center (DMC) we have been developing web service data access interfaces for our, primarily seismological, repositories for five years. These interfaces have become the primary access mechanisms for all data extraction from the DMC. For the last two years the DMC has been a principal participant in the GeoWS project, which aims to develop common web service interfaces for data access across hydrology, geodesy, seismology, marine geophysics, atmospheric and other geoscience disciplines. By extending our approach we have converged, along with other project members, on a web service interface and presentation design appropriate for geoscience and other data. The key principles of the approach include using a simple subset of RESTful concepts, common calling conventions whenever possible, a common tabular text data set convention, human-readable documentation and tools to help scientific end users learn how to use the interfaces. The common tabular text format, called GeoCSV, has been incorporated into the DMC's seismic station and event (earthquake) services. In addition to modifying our existing services, we have developed prototype GeoCSV web services for data sets managed by external (unfunded) collaborators. These prototype services include interfaces for data sets at NGDC/NCEI (water level tides and meteorological satellite measurements), INTERMAGNET repository and UTEP gravity and magnetic measurements. In progress are interfaces for WOVOdat (volcano observatory measurements), NEON (ecological observatory measurements) and more. An important goal of our work is to build interfaces usable by non-technologist end users. We find direct usability by researchers to be a major factor in cross-discipline data use, which itself is a key to solving complex research questions. In addition to data discovery and collection by end users, these interfaces provide a foundation upon which federated data access and brokering systems are already being

  19. Geo-Correction of High-Resolution Imagery Using Fast Template Matching on a GPU in Emergency Mapping Contexts

    Directory of Open Access Journals (Sweden)

    Martina Giovalli

    2013-09-01

    Full Text Available The increasing availability of satellite imagery acquired by existing and new sensors allows a wide variety of new applications that depend on the use of diverse spectral and spatial resolution data sets. One of the pre-conditions for the use of hybrid image data sets is a consistent geo-correction capacity. We demonstrate how a novel fast template matching approach implemented on a graphics processing unit (GPU allows us to accurately and rapidly geo-correct imagery in an automated way. The key difference with existing geo-correction approaches, which do not use a GPU, is the possibility to match large source image segments (8,192 by 8,192 pixels with relatively large templates (512 by 512 pixels significantly faster. Our approach is sufficiently robust to allow for the use of various reference data sources. The need for accelerated processing is relevant in our application context, which relates to mapping activities in the European Copernicus emergency management service. Our new method is demonstrated over an area northwest of Valencia (Spain for a large forest fire event in July 2012. We use the Disaster Monitoring Constellation’s (DMC DEIMOS-1 and RapidEye imagery for the delineation of burnt scar extent. Automated geo-correction of each full resolution image set takes approximately one minute. The reference templates are taken from the TerraColor data set and the Spanish national ortho-imagery database, through the use of dedicated web map services. Geo-correction results are compared to the vector sets derived in the Copernicus emergency service activation request.

  20. Nitrogen dioxide observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument: Retrieval algorithm and measurements during DISCOVER-AQ Texas 2013

    Science.gov (United States)

    Nowlan, Caroline R.; Liu, Xiong; Leitch, James W.; Chance, Kelly; González Abad, Gonzalo; Liu, Cheng; Zoogman, Peter; Cole, Joshua; Delker, Thomas; Good, William; Murcray, Frank; Ruppert, Lyle; Soo, Daniel; Follette-Cook, Melanie B.; Janz, Scott J.; Kowalewski, Matthew G.; Loughner, Christopher P.; Pickering, Kenneth E.; Herman, Jay R.; Beaver, Melinda R.; Long, Russell W.; Szykman, James J.; Judd, Laura M.; Kelley, Paul; Luke, Winston T.; Ren, Xinrong; Al-Saadi, Jassim A.

    2016-06-01

    The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA Falcon aircraft in its first intensive field measurement campaign during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) Earth Venture Mission over Houston, Texas, in September 2013. Measurements of backscattered solar radiation between 420 and 465 nm collected on 4 days during the campaign are used to determine slant column amounts of NO2 at 250 m × 250 m spatial resolution with a fitting precision of 2.2 × 1015 moleculescm-2. These slant columns are converted to tropospheric NO2 vertical columns using a radiative transfer model and trace gas profiles from the Community Multiscale Air Quality (CMAQ) model. Total column NO2 from GeoTASO is well correlated with ground-based Pandora observations (r = 0.90 on the most polluted and cloud-free day of measurements and r = 0.74 overall), with GeoTASO NO2 slightly higher for the most polluted observations. Surface NO2 mixing ratios inferred from GeoTASO using the CMAQ model show good correlation with NO2 measured in situ at the surface during the campaign (r = 0.85). NO2 slant columns from GeoTASO also agree well with preliminary retrievals from the GEO-CAPE Airborne Simulator (GCAS) which flew on the NASA King Air B200 (r = 0.81, slope = 0.91). Enhanced NO2 is resolvable over areas of traffic NOx emissions and near individual petrochemical facilities.

  1. Nitrogen dioxide observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO airborne instrument: retrieval algorithm and measurements during DISCOVER-AQ Texas 2013

    Directory of Open Access Journals (Sweden)

    C. R. Nowlan

    2015-12-01

    Full Text Available The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO airborne instrument is a testbed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA Falcon aircraft in its first intensive field measurement campaign during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ Earth Venture Mission over Houston, Texas in September 2013. Measurements of backscattered solar radiation between 420–465 nm collected on four days during the campaign are used to determine slant column amounts of NO2 at 250 m × 250 m spatial resolution with a fitting precision of 2.2 × 1015 molecules cm−2. These slant columns are converted to tropospheric NO2 vertical columns using a radiative transfer model and trace gas profiles from the Community Multiscale Air Quality (CMAQ model. Total column NO2 from GeoTASO is well correlated with ground-based Pandora observations (r = 0.90 on the most polluted and cloud-free day of measurements, with GeoTASO NO2 slightly higher for the most polluted observations. Surface NO2 mixing ratios inferred from GeoTASO using the CMAQ model show good correlation with NO2 measured in situ at the surface during the campaign (r = 0.91 for the most polluted day. NO2 slant columns from GeoTASO also agree well with preliminary retrievals from the GEO-CAPE Airborne Simulator (GCAS which flew on the NASA King Air B200 (r = 0.84, slope = 0.94. Enhanced NO2 is resolvable over areas of traffic NOx emissions and near individual petrochemical facilities.

  2. GeoPad and GeoPocket: GIS-Enabled Field Science Education

    Science.gov (United States)

    Knoop, P. A.; van der Pluijm, B.

    2005-12-01

    Over the past three years we have successfully incorporated and evaluated the use of field-based information technology in introductory through senior-level field courses offered at the University of Michigan's Camp Davis Geology Field Station, near Jackson, WY. The use of GeoPads (field-durable Tablet PCs) and GeoPockets (field-durable Pocket PCs) -- both equipped with GIS, GPS, wireless networking, electronic notebook and other pertinent software -- have significantly enhanced our field exercises and excursions, for both students and instructors. In addition to describing our on-going work, the results of an external, independent review of GeoPad-curriculum integration are presented. For example, using GeoPads to teach field mapping not only supports the traditional approaches and advantages of field instruction, but also offers important benefits in the development of students' spatial reasoning skills. Students are able to record observations and directly create geologic maps in the field, using a combination of an electronic field notebook (Microsoft OneNote) tightly integrated with intuitive, pen-enabled GIS software (ArcGIS-ArcMap). Specifically, this arrangement permits students to analyze and manipulate their data in multiple contexts and representations -- while still in the field -- using both traditional 2-D map views, as well as richer 3-D contexts. Such enhancements provide students with powerful exploratory tools that aid the development of spatial reasoning skills, allowing more intuitive interactions with 2-D representations of our 3-D world. Additionally, field-based GIS mapping enables better error-detection, through immediate interaction with current observations in the context of both supporting data (e.g., topographic maps, aerial photos, magnetic surveys) and students' ongoing observations. GeoPockets provide instructional staff with a more portable, though less feature-rich device, which is highly suitable to the role of "electronic

  3. A virtual reference satellite differential method for relative correction of satellite ephemeris errors

    Science.gov (United States)

    Cai, Chenglin; Li, Xiaohui; Wu, Haitao

    2010-12-01

    In order to solve the problems that the novel wide area differential method on the satellite clock and ephemeris relative correction (CERC) in the non-geostationary orbit satellite constellation, a virtual reference satellite (VRS) differential principle using relative correction of satellite ephemeris errors is proposed. It is referred to be as the VRS differential principle, and the elaboration is focused on the construction of pseudo-range errors of VRS. Through qualitative analysis, it can be found that the impact of the satellite's clock and ephemeris errors on positioning can basically be removed and the users' positioning errors are near zero. Through simulation analysis of the differential performance, it is verified that the differential method is universal in all kinds of satellite navigation systems with geostationary orbit (GEO) constellation, Medium orbit (MEO) constellation or hybrid orbit constellation, and it has insensitivity to abnormal aspects of a satellite ephemeris and clock. Moreover, the real time positioning accuracy of differential users can be maintained within several decimeters after the pseudo-range measurement noise is effectively weakened or eliminated.

  4. Integrated Geo Hazard Management System in Cloud Computing Technology

    Science.gov (United States)

    Hanifah, M. I. M.; Omar, R. C.; Khalid, N. H. N.; Ismail, A.; Mustapha, I. S.; Baharuddin, I. N. Z.; Roslan, R.; Zalam, W. M. Z.

    2016-11-01

    Geo hazard can result in reducing of environmental health and huge economic losses especially in mountainous area. In order to mitigate geo-hazard effectively, cloud computer technology are introduce for managing geo hazard database. Cloud computing technology and it services capable to provide stakeholder's with geo hazards information in near to real time for an effective environmental management and decision-making. UNITEN Integrated Geo Hazard Management System consist of the network management and operation to monitor geo-hazard disaster especially landslide in our study area at Kelantan River Basin and boundary between Hulu Kelantan and Hulu Terengganu. The system will provide easily manage flexible measuring system with data management operates autonomously and can be controlled by commands to collects and controls remotely by using “cloud” system computing. This paper aims to document the above relationship by identifying the special features and needs associated with effective geohazard database management using “cloud system”. This system later will use as part of the development activities and result in minimizing the frequency of the geo-hazard and risk at that research area.

  5. Topic Modelling for Object-Based Unsupervised Classification of VHR Panchromatic Satellite Images Based on Multiscale Image Segmentation

    Directory of Open Access Journals (Sweden)

    Li Shen

    2017-08-01

    Full Text Available Image segmentation is a key prerequisite for object-based classification. However, it is often difficult, or even impossible, to determine a unique optimal segmentation scale due to the fact that various geo-objects, and even an identical geo-object, present at multiple scales in very high resolution (VHR satellite images. To address this problem, this paper presents a novel unsupervised object-based classification for VHR panchromatic satellite images using multiple segmentations via the latent Dirichlet allocation (LDA model. Firstly, multiple segmentation maps of the original satellite image are produced by means of a common multiscale segmentation technique. Then, the LDA model is utilized to learn the grayscale histogram distribution for each geo-object and the mixture distribution of geo-objects within each segment. Thirdly, the histogram distribution of each segment is compared with that of each geo-object using the Kullback-Leibler (KL divergence measure, which is weighted with a constraint specified by the mixture distribution of geo-objects. Each segment is allocated a geo-object category label with the minimum KL divergence. Finally, the final classification map is achieved by integrating the multiple classification results at different scales. Extensive experimental evaluations are designed to compare the performance of our method with those of some state-of-the-art methods for three different types of images. The experimental results over three different types of VHR panchromatic satellite images demonstrate the proposed method is able to achieve scale-adaptive classification results, and improve the ability to differentiate the geo-objects with spectral overlap, such as water and grass, and water and shadow, in terms of both spatial consistency and semantic consistency.

  6. Potential of a geostationary geoCARB mission to estimate surface emissions of CO2, CH4 and CO in a polluted urban environment: case study Shanghai

    Science.gov (United States)

    O'Brien, Denis M.; Polonsky, Igor N.; Utembe, Steven R.; Rayner, Peter J.

    2016-09-01

    This paper describes a numerical experiment to test the ability of the proposed geoCARB satellite to estimate emissions of trace gases (CO2, CH4 and CO) in the polluted urban environment of Shanghai. The meteorology over Shanghai is simulated with the Weather Research and Forecasting (WRF) model for a 9-day period in August 2010. The meteorology includes water and ice clouds. The chemistry version of WRF (WRF-Chem V3.6.1) is used to predict the chemical composition, mass density and number density of aerosol species. Spectra in the bands measured by geoCARB are calculated, including the effects of polarisation and multiple scattering of radiation by clouds, aerosols and molecules. Instrument noise is added, and column-averaged trace-gas mole fractions are estimated from the noisy spectra using an algorithm based on that for the Greenhouse Gases Observing Satellite (GOSAT) and the Orbiting Carbon Observatory-2 (OCO-2) but adapted to geoCARB. As expected, the high aerosol loadings are challenging. However, when the retrieval algorithm is provided with regionally adjusted aerosol optical properties, as might be determined from observations of dark targets within the field of regard, the accuracies of retrieved concentrations are comparable to those reported earlier for geoCARB. Statistics of the errors in the retrieved column-averaged concentrations are used to predict the reduction in uncertainty of surface emissions possible with remotely sensed data.

  7. The United States' Next Generation of Atmospheric Composition and Coastal Ecosystem Measurements: NASA's Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission

    Science.gov (United States)

    Fishman, J.; Iraci, Laura T.; Al-Saddi, J.; Chance, K.; Chavez, F.; Chin, M.; Coble, P.; Davis, C.; DiGiacomo, P. M.; Edwards, D.; Eldering, A.; Goes, J.; Herman, J.; Hu, C.; Jacob, D. J.; Jordan, C.; Kawa, S. R.; Key, R.; Liu, X.; Lohrenz, S.; Mannino, A.; Natraj, V.; Neil, D.; Neu, J.; Newchurch, M.; Pickering, K.; Salisbury, J.; Sosik, H.; Subramaniam, A.; Tzortziou, M; Wang, J.; Wang, M.

    2012-01-01

    The Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission was recommended by the National Research Council's (NRC's) Earth Science Decadal Survey to measure tropospheric trace gases and aerosols and coastal ocean phytoplankton, water quality, and biogeochemistry from geostationary orbit, providing continuous observations within the field of view. To fulfill the mandate and address the challenge put forth by the NRC, two GEO-CAPE Science Working Groups (SWGs), representing the atmospheric composition and ocean color disciplines, have developed realistic science objectives using input drawn from several community workshops. The GEO-CAPE mission will take advantage of this revolutionary advance in temporal frequency for both of these disciplines. Multiple observations per day are required to explore the physical, chemical, and dynamical processes that determine tropospheric composition and air quality over spatial scales ranging from urban to continental, and over temporal scales ranging from diurnal to seasonal. Likewise, high-frequency satellite observations are critical to studying and quantifying biological, chemical, and physical processes within the coastal ocean. These observations are to be achieved from a vantage point near 95deg-100degW, providing a complete view of North America as well as the adjacent oceans. The SWGs have also endorsed the concept of phased implementation using commercial satellites to reduce mission risk and cost. GEO-CAPE will join the global constellation of geostationary atmospheric chemistry and coastal ocean color sensors planned to be in orbit in the 2020 time frame.

  8. The principle of a navigation constellation composed of SIGSO communication satellites

    Institute of Scientific and Technical Information of China (English)

    Hai-Fu Ji; Li-Hua Ma; Guo-Xiang Ai; Hu-Li Shi

    2013-01-01

    The Chinese Area Positioning System (CAPS),a navigation system based on geostationary orbit (GEO) communication satellites,was developed in 2002 by astronomers at Chinese Academy of Sciences.Extensive positioning experiments of CAPS have been performed since 2005.On the basis of CAPS,this paper studies the principle of a navigation constellation composed of slightly inclined geostationary orbit (SIGSO) communication satellites.SIGSO satellites are derived from GEO satellites which are near the end of their operational life by inclined orbit operation.Considering the abundant frequency resources of SIGSO satellites,multi-frequency observations could be conducted to enhance the precision of pseudorange measurements and ameliorate the positioning performance.A constellation composed of two GEO satellites and four SIGSO satellites with an inclination of 5° can provide service to most of the territory of China with a maximum position dilution of precision (PDOP) over 24 h of less than 42.With synthetic utilization of the truncated precise code and a physical augmentation factor in four frequencies,the navigation system with this constellation is expected to obtain comparable positioning performance to that of the coarse acquisition code of the Global Positioning System (GPS).When the new method of code-carrier phase combinations is adopted,the system has the potential to possess commensurate accuracy with the precise code in GPS.Additionally,the copious frequency resources can also be used to develop new anti-interference techniques and integrate navigation and communication.

  9. Bi-static Optical Observations of GEO Objects

    Science.gov (United States)

    Seitzer, Patrick; Barker, Edwin S.; Cowardin, Heather; Lederer, Susan M.; Buckalew, Brent

    2014-01-01

    A bi-static study of objects at Geosynchronous Earth Orbit (GEO) was conducted using two ground-based wide-field optical telescopes. The University of Michigan's 0.6-m MODEST (Michigan Orbital Debris Survey Telescope) located at the Cerro Tololo Inter- American Observatory in Chile was employed in a series of coordinated observations with the U.S. Naval Observatory's (USNO) 1.3-m telescope at the USNO Flagstaff Station near Flagstaff, Arizona, USA. The goals of this project are twofold: (1) Obtain optical distances to known and unknown objects at GEO from the difference in the observed topocentric position of objects measured with respect to a reference star frame. The distance can be derived directly from these measurements, and is independent of any orbital solution. The wide geographical separation of these two telescopes means that the parallax difference is larger than ten degrees, and (2) Compare optical photometry in similar filters of GEO objects taken during the same time period from the two sites. The object's illuminated surfaces presented different angles of reflected sunlight to the two telescopes.During a four hour period on the night.of 22 February 2014 (UT), coordinated observations were obtained for eight different GEO positions. Each coordinated observation sequence was started on the hour or half-hour, and was selected to ensure the same cataloged GEO object was available in the field of view of both telescopes during the thirty minute observing sequence. GEO objects were chosen to be both controlled and uncontrolled at a range of orbital inclinations, and the objects were not tracked. Instead both telescopes were operated with all drives off in GEO survey mode to discover un-cataloged objects at GEO. The initial results from this proof-of-concept observing run will be presented, with the intent of laying the foundation for future large-scale bi-static observing campaigns of the GEO regime.

  10. Application of Single-Mode Fiber-Coupled Receivers in Optical Satellite to High-Altitude Platform Communications

    Directory of Open Access Journals (Sweden)

    Oswald Wallner

    2008-05-01

    Full Text Available In a free-space optical communication system employing fiber-optic components, the phasefront distortions induced by atmospheric turbulence limit the efficiency with which the laser beam is coupled into a single-mode fiber. We analyze different link scenarios including a geostationary (GEO satellite, a high-altitude platform (HAP, and an optical ground station (OGS. Single-mode coupled optically preamplified receivers allow for efficient suppression of background noise and highly sensitive detection. While GEO-to-OGS communication suffers from atmospheric turbulence, we demonstrate that GEO-to-HAP communication allows for close to diffraction-limited performance when applying tip-tilt correction.

  11. Application of Single-Mode Fiber-Coupled Receivers in Optical Satellite to High-Altitude Platform Communications

    Directory of Open Access Journals (Sweden)

    Fidler Franz

    2008-01-01

    Full Text Available Abstract In a free-space optical communication system employing fiber-optic components, the phasefront distortions induced by atmospheric turbulence limit the efficiency with which the laser beam is coupled into a single-mode fiber. We analyze different link scenarios including a geostationary (GEO satellite, a high-altitude platform (HAP, and an optical ground station (OGS. Single-mode coupled optically preamplified receivers allow for efficient suppression of background noise and highly sensitive detection. While GEO-to-OGS communication suffers from atmospheric turbulence, we demonstrate that GEO-to-HAP communication allows for close to diffraction-limited performance when applying tip-tilt correction.

  12. Comparison of gravimetric geoids with GEOS 3 altimetric geoid

    Science.gov (United States)

    Chapman, M. E.; Talwani, M.

    1979-01-01

    The paper examines how well GEOS 3 radar altimeter estimates of geoid height compare with data from independently determined gravimetric geoids. To this end, GEOS 3 altimeter estimates of geoid height are compared with 1 by 1 deg gravimetric geoids in the North Atlantic, Northwest Pacific, and Indian oceans. There exist constant offsets and long-wavelength discrepancies between the two sets of data. Although some difficulties exist with constant offset and long-wavelength discrepancies, the GEOS 3 radar altimeter appears to detect geological features such as deep-sea trenches and is an excellent instrument for acquiring measurements of the shape of the ocean surface.

  13. GEO label: The General Framework for Labeling and Certification

    Science.gov (United States)

    Bye, B. L.; McCallum, I.; Maso, J.

    2012-04-01

    The Group on Earth Observations (GEO) is coordinating efforts to build a Global Earth Observation System of Systems, or GEOSS. As part of a strategy to increase the involvement of the science and technology community in GEOSS, both as users and developers of GEOSS itself, GEO decided to develop a GEO label concept related to the scientific relevance, quality, acceptance and societal needs for services and data sets of GEOSS. The development of a GEO label is included in the GEO work plan and several projects address the challenges of developing a GEO label concept. Within the different projects developing the GEO label, various perspectives and approaches are being applied. In order to arrive at a generally accepted GEO label concept, a common understanding and basic knowledge of labeling is necessary. Assessment of quality of internationally standardized Earth observation data products implies possible certification. A general understanding of the framework for international standards and certification will also contribute to a more coherent discussion and more efficient development of a GEO label. We will describe the general labeling and certification framework emphasizing the relation to the three elements of the GEO label: quality, user acceptance and relevance. Based on a survey of international labels done by the EGIDA project, we have analyzed the legal framework and organization of labels and certification. We will discuss the frameworks for certification, user ratings, registration and analysis of user requirements. Quality assessment is a particular focus of the analysis and is based on the work done by the GeoViQua project. A GEO label will function both as a data distribution strategy and as a general management system for data. Through a label users can compare different data sets and get access to more information about the relevant data, including quality. A label will provide traceability of data both in the interest of users as well as data

  14. Utilizing Windows Azure to Support Geo-science Applications

    Science.gov (United States)

    Xia, J.

    2014-12-01

    Windows Azure is a cloud computing platform and infrastructure, created by Microsoft for developing, deploying and managing applications through global networks. It provides Platform as a service (PaaS) which have been widely used in different domains to support scientific studies. This paper experiences the feasibility of utilizing Windows Azure to support different type of geo-science applications. Specially, the load balancing feature of Azure is used to address intensive concurrent access for geo-science data; cloud-based database is utilized for support Big Spatial data management; and the global deployment feature is used to improve the evaluation accuracy for geo-science services.

  15. GeoLab: A Geological Workstation for Future Missions

    Science.gov (United States)

    Evans, Cynthia; Calaway, Michael; Bell, Mary Sue; Li, Zheng; Tong, Shuo; Zhong, Ye; Dahiwala, Ravi

    2014-01-01

    The GeoLab glovebox was, until November 2012, fully integrated into NASA's Deep Space Habitat (DSH) Analog Testbed. The conceptual design for GeoLab came from several sources, including current research instruments (Microgravity Science Glovebox) used on the International Space Station, existing Astromaterials Curation Laboratory hardware and clean room procedures, and mission scenarios developed for earlier programs. GeoLab allowed NASA scientists to test science operations related to contained sample examination during simulated exploration missions. The team demonstrated science operations that enhance theThe GeoLab glovebox was, until November 2012, fully integrated into NASA's Deep Space Habitat (DSH) Analog Testbed. The conceptual design for GeoLab came from several sources, including current research instruments (Microgravity Science Glovebox) used on the International Space Station, existing Astromaterials Curation Laboratory hardware and clean room procedures, and mission scenarios developed for earlier programs. GeoLab allowed NASA scientists to test science operations related to contained sample examination during simulated exploration missions. The team demonstrated science operations that enhance the early scientific returns from future missions and ensure that the best samples are selected for Earth return. The facility was also designed to foster the development of instrument technology. Since 2009, when GeoLab design and construction began, the GeoLab team [a group of scientists from the Astromaterials Acquisition and Curation Office within the Astromaterials Research and Exploration Science (ARES) Directorate at JSC] has progressively developed and reconfigured the GeoLab hardware and software interfaces and developed test objectives, which were to 1) determine requirements and strategies for sample handling and prioritization for geological operations on other planetary surfaces, 2) assess the scientific contribution of selective in-situ sample

  16. Improvement and Simulation of an Autonomous Time Synchronization Algorithm for a Layered Satellite Constellation

    Directory of Open Access Journals (Sweden)

    Feijiang Huang

    2013-01-01

    Full Text Available Autonomous time synchronization for satellite constellations is a key technology to establish a constellation system time without the use of a ground station. The characteristics of satellite visibility time for layered satellite constellations containing geostationary earth orbit (GEO, inclined geosynchronous orbit (IGSO, and medium earth orbit (MEO satellites are simulated by establishing a visible satellite model. Based on the satellite visible simulation results for a layered constellation, this study investigates the autonomous time synchronization algorithm that corresponds to the layered constellation structure, analyzes the main error of the time synchronization algorithm, and proposes methods to improve the characteristics of satellite movement in the constellation. This study uses an improved two-way time synchronization algorithm for autonomous time synchronization in the GEO-MEO satellite layer of a layered satellite constellation. The simulation results show that in a condition with simulation errors, the time synchronization precision of this improved algorithm can be controlled within 5 ns and used in high-precision autonomous time synchronization between layered satellite constellations.

  17. The rise and fall of COMSAT technology, business, and government in satellite communications

    CERN Document Server

    Whalen, D

    2014-01-01

    Satellite communications grosses over 100 billion annually and is heading toward 200 billion. COMSAT started all of this in 1963 when it was organized in compliance with the Communications Satellite Act of 1962. COMSAT was responsible for choosing geosynchronous earth orbit (GEO), forming INTELSAT, and generally promoting the technological change that saw satellite power increase from the 40 watts of Early Bird (INTELSAT I) to the almost 10 kilowatts of INTELSAT IX; earth station antennas were reduced from 30 meters to 1 meter. The business of satellite communications was expanded to mobile co

  18. Mashup of Geo and Space Science Data Provided via Relational Databases in the Semantic Web

    Science.gov (United States)

    Ritschel, B.; Seelus, C.; Neher, G.; Iyemori, T.; Koyama, Y.; Yatagai, A. I.; Murayama, Y.; King, T. A.; Hughes, J. S.; Fung, S. F.; Galkin, I. A.; Hapgood, M. A.; Belehaki, A.

    2014-12-01

    The use of RDBMS for the storage and management of geo and space science data and/or metadata is very common. Although the information stored in tables is based on a data model and therefore well organized and structured, a direct mashup with RDF based data stored in triple stores is not possible. One solution of the problem consists in the transformation of the whole content into RDF structures and storage in triple stores. Another interesting way is the use of a specific system/service, such as e.g. D2RQ, for the access to relational database content as virtual, read only RDF graphs. The Semantic Web based -proof of concept- GFZ ISDC uses the triple store Virtuoso for the storage of general context information/metadata to geo and space science satellite and ground station data. There is information about projects, platforms, instruments, persons, product types, etc. available but no detailed metadata about the data granuals itself. Such important information, as e.g. start or end time or the detailed spatial coverage of a single measurement is stored in RDBMS tables of the ISDC catalog system only. In order to provide a seamless access to all available information about the granuals/data products a mashup of the different data resources (triple store and RDBMS) is necessary. This paper describes the use of D2RQ for a Semantic Web/SPARQL based mashup of relational databases used for ISDC data server but also for the access to IUGONET and/or ESPAS and further geo and space science data resources. RDBMS Relational Database Management System RDF Resource Description Framework SPARQL SPARQL Protocol And RDF Query Language D2RQ Accessing Relational Databases as Virtual RDF Graphs GFZ ISDC German Research Centre for Geosciences Information System and Data Center IUGONET Inter-university Upper Atmosphere Global Observation Network (Japanese project) ESPAS Near earth space data infrastructure for e-science (European Union funded project)

  19. Evaluation of GEOS-5 sulfur dioxide simulations during the Frostburg, MD 2010 field campaign

    Directory of Open Access Journals (Sweden)

    V. Buchard

    2013-08-01

    Full Text Available Sulfur dioxide (SO2 is a major atmospheric pollutant with a strong anthropogenic component mostly produced by the combustion of fossil fuel and other industrial activities. As a precursor of sulfate aerosols that affect climate, air quality, and human health, this gas needs to be monitored on a global scale. Global climate and chemistry models including aerosol processes along with their radiative effects are important tools for climate and air quality research. Validation of these models against in-situ and satellite measurements is essential to ascertain the credibility of these models and to guide model improvements. In this study the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART module running on-line inside the Goddard Earth Observing System version 5 (GEOS-5 model is used to simulate aerosol and SO2 concentrations. Data taken in November 2010 over Frostburg, Maryland during an SO2 field campaign involving ground instrumentation and aircraft are used to evaluate GEOS-5 simulated SO2 concentrations. Preliminary data analysis indicated the model overestimated surface SO2 concentration, which motivated the examination of mixing processes in the model and the specification of SO2 anthropogenic emission rates. As a result of this analysis, a revision of anthropogenic emission inventories in GEOS-5 was implemented, and the vertical placement of SO2 sources was updated. Results show that these revisions improve the model agreement with observations locally and in regions outside the area of this field campaign. In particular, we use the ground-based measurements collected by the United States Environmental Protection Agency (US EPA for the year 2010 to evaluate the revised model simulations over North America.

  20. Evaluation of GEOS-5 Sulfur Dioxide Simulations During the Frostburg, MD 2010 Field Campaign.

    Science.gov (United States)

    Buchard, V.; Da Silva, A. M.; Colarco, P.; Krotkov, N.; Dickerson, R. R.; Stehr, J. W.; Mount, G.; Spenei, E.; Arkinson, H. L.; He, H.

    2013-01-01

    Sulfur dioxide (SO2) is a major atmospheric pollutant with a strong anthropogenic component mostly produced by the combustion of fossil fuel and other industrial activities. As a precursor of sulfate aerosols that affect climate, air quality, and human health, this gas needs to be monitored on a global scale. Global climate and chemistry models including aerosol processes along with their radiative effects are important tools for climate and air quality research. Validation of these models against in-situ and satellite measurements is essential to ascertain the credibility of these models and to guide model improvements. In this study the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) module running on-line inside the Goddard Earth Observing System version 5 (GEOS-5) model is used to simulate aerosol and SO2 concentrations. Data taken in November 2010 over Frostburg, Maryland during an SO2 field campaign involving ground instrumentation and aircraft are used to evaluate GEOS-5 simulated SO2 concentrations. Preliminary data analysis indicated the model overestimated surface SO2 concentration, which motivated the examination of mixing processes in the model and the specification of SO2 anthropogenic emission rates. As a result of this analysis, a revision of anthropogenic emission inventories in GEOS-5 was implemented, and the vertical placement of SO2 sources was updated. Results show that these revisions improve the model agreement with observations locally and in regions outside the area of this field campaign. In particular, we use the ground-based measurements collected by the United States Environmental Protection Agency (US EPA) for the year 2010 to evaluate the revised model simulations over North America.

  1. Expected Position Error for an Onboard Satellite GPS Receiver

    Science.gov (United States)

    2015-03-01

    that supports GPS, Galileo, Global’naya Navigatsionnaya Sputnikovaya Sistema (GLONASS), and Quasi-Zenith Satellite System GNSSs. It is designed as a...compared to the main beam half cone angle listed in the GPS Interface Control Document (ICD) [19]. 29 Sidelobes Considered. Power in the sidelobes is...Centered Inertial ENU East-North-Up GDOP Geometric Dilution of Precision GEO Geostationary Orbit GLONASS Global’naya Navigatsionnaya Sputnikovaya Sistema

  2. Methods of rapid orbit forecasting after maneuvers for geostationary satellites

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A geostationary(GEO) satellite may serve as a navigation satellite,but there is a problem that maneuvers frequently occur and the forces are difficult to model.Based on the technique of determining satellite orbits by transfer,a predicted orbit with high accuracy may be achieved by the method of statis-tical orbit determination in case of no maneuver force.The predicted orbit will soon be invalid after the maneuver starts,and it takes a long time to get a valid orbit after the maneuver ends.In order to improve ephemeris usability,the method of rapid orbit forecasting after maneuvers is studied.First,GEO satellite movement is analyzed in case of maneuvers based on the observation from the orbit meas-urement system by transfer.Then when a GEO satellite is in the free status just after maneuvers,the short arc observation is used to forecast the orbit.It is assumed that the common system bias and biases of each station are constant,which can be obtained from orbit determination with long arc observations.In this way,only 6 orbit elements would be solved by the method of statistical orbit determination,and the ephemeris with high accuracy may be soon obtained.Actual orbit forecasting with short arc observation for SINOSAT-1 satellite shows that,with the tracking network available,the precision of the predicted orbit(RMS of O-C) can reach about 5 m with 15 min arc observation,and about 3 m with 30 min arc observation.

  3. Formulation of caesium based and caesium containing geo-polymers

    Energy Technology Data Exchange (ETDEWEB)

    Berger, S.; Joussot-Dubien, C.; Frizon, F. [CEA Valrho, Dir. de l' Energie Nucleaire, DEN, Decontamination and Conditioning Department, DEN/DTCD/SPDE/L2ED, 30 - Marcoule (France)

    2009-10-15

    Cement encapsulation is widely used as a low- and intermediate level radioactive waste immobilisation process. Among these wastes, caesium ions are poorly immobilised by Portland cement based materials. This work consists of an experimental investigation into the ability of geo-polymers to effectively encapsulate this chemical species and to determine the impact of caesium incorporation on the geo-polymer properties. Geo-polymers were synthesised with several compositions based on the activation of metakaolin with an alkali hydroxide solution containing caesium. The setting time, mineralogy, porosity and mechanical properties of the samples were examined for one month. Leach tests were conducted during the same period to determine the immobilisation efficiency. The results depend to a large extent on the composition of the activation solution in terms of soluble silica content and alkali used. These parameters determine both the degree of condensation and the geo-polymer composition. (authors)

  4. Research on high dynamic range information capture of GEO camera

    Science.gov (United States)

    Huang, Sijie; Chen, Fansheng; Gong, Xueyi

    2014-07-01

    A high dynamic range imaging method of GEO staring imaging is proposed based on radiance simulation of GEO remote sensing targets and analysis of foreign and domestic remote sensing payload characteristics. Due to the high temporal resolution of GEO staring imaging, multiple exposure method is used and image sequences are captured with different integration times; Then a high dynamic range image is obtained after fusion with the contrast of neighborhood pixel values being the weighting factor. Finally experiments are done in lab with visible plane array 2048*2048 imaging system for verifying multiple exposure test. It can be proved that using multiple exposure capture fusion method can obtain an 11 bit high dynamic range image. The essence of the method is that it sacrifices time resolution in exchange for high dynamic range, which overcomes the defect of small dynamic range of single exposure and is of practical significance in terms of GEO high dynamic range information capture.

  5. Chlorine isotopes potential as geo-chemical tracers

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; Pradhan, U.K.; Banerjee, R.

    The potential of chlorine isotopes as tracers of geo-chemical processes of earth and the oceans is highlighted based on systematic studies carried out in understanding the chlorine isotope fractionation mechanism, its constancy in seawater and its...

  6. Application of geo-information science methods in ecotourism exploitation

    Science.gov (United States)

    Dong, Suocheng; Hou, Xiaoli

    2004-11-01

    Application of geo-information science methods in ecotourism development was discussed in the article. Since 1990s, geo-information science methods, which take the 3S (Geographic Information System, Global Positioning System, and Remote Sensing) as core techniques, has played an important role in resources reconnaissance, data management, environment monitoring, and regional planning. Geo-information science methods can easily analyze and convert geographic spatial data. The application of 3S methods is helpful to sustainable development in tourism. Various assignments are involved in the development of ecotourism, such as reconnaissance of ecotourism resources, drawing of tourism maps, dealing with mass data, and also tourism information inquire, employee management, quality management of products. The utilization of geo-information methods in ecotourism can make the development more efficient by promoting the sustainable development of tourism and the protection of eco-environment.

  7. Feasibility study of a solar power satellite system configured by formation flying

    Energy Technology Data Exchange (ETDEWEB)

    Takeichi, Noboru; Ueno, Hiroshi; Oda, Mitsushige [Japan Aerospace Exploration Agency (JAXA), Inst. of Space Technology and Aeronautics, Tsukuba, Ibaraki (Japan)

    2005-11-15

    This paper presents a new concept of a solar power satellite system configured by formation flying. In this concept, the solar power satellite system consists of sunlight reflectors and an energy generator-transmitter. The energy generator- transmitter is on a common GEO, and the reflectors are placed on the north and south by using solar pressure to raise their orbits from GEO. Therefore, the orbits of the reflectors and that of the energy generator-transmitter make three parallel GEOs. The feasibility of the concept and its requirements are also discussed, focusing on the orbital and attitude mechanics of the reflector. Because the tilt angle of the sunlight changes with the turning of the seasons, it is sometimes necessary to raise the orbit by thrusters especially around the solstice. For attitude dynamics, spin stabilization and thruster control are discussed as the attitude control strategies against the gravity gradient torque, which acts as a persistent periodic disturbance. (Author)

  8. A New Index to Perform Shadow Detection in GeoEye-1 Images

    Directory of Open Access Journals (Sweden)

    Claudio Meneghini

    2015-10-01

    Full Text Available With the introduction of new satellites for earth monitoring characterized by very high resolution (VHR sensors, new algorithms to recognize shadow in the supplied images are necessary. Automatic shadow detection can enhance the interpretability of the images in several applications such as classification and change detection. Several approaches are present in literature for shadow detection and their adaptation and particularization for VHR satellite images are still in evolution. The goal of this paper is to propose a new index for shadow detection based on multispectral files processing. GeoEye-1 satellite data are used for this study: IHS pan-sharpening method is applied to transfer pixel dimensions of the panchromatic image (spatial resolution: 0.5 m x 0.5 m into the multispectral images (2 m x 2 m; an index named ERGAS is used to test the quality of the resulting raster files. Dealing with the problem of the shadow detection, a new index is defined to identify the affected pixels both in the original as well as pan-sharpened images. The results are compared with them by another index named ratio that is generally applied for shadow detection in multispectral images: issues and advantages, derived by using the proposed technique, are discussed.

  9. Google Earth and Geo Applications: A Toolset for Viewing Earth's Geospatial Information

    Science.gov (United States)

    Tuxen-Bettman, K.

    2016-12-01

    Earth scientists measure and derive fundamental data that can be of broad general interest to the public and policy makers. Yet, one of the challenges that has always faced the Earth science community is how to present their data and findings in an easy-to-use and compelling manner. Google's Geo Tools offer an efficient and dynamic way for scientists, educators, journalists and others to both access data and view or tell stories in a dynamic three-dimensional geospatial context. Google Earth in particular provides a dense canvas of satellite imagery on which can be viewed rich vector and raster datasets using the medium of Keyhole Markup Language (KML). Through KML, Google Earth can combine the analytical capabilities of Earth Engine, collaborative mapping of My Maps, and storytelling of Tour Builder and more to make Google's Geo Applications a coherent suite of tools for exploring our planet.https://earth.google.com/https://earthengine.google.com/https://mymaps.google.com/https://tourbuilder.withgoogle.com/https://www.google.com/streetview/

  10. GEO light imaging national testbed (GLINT) heliostat design and testing status

    Science.gov (United States)

    Thornton, Marcia A.; Oldenettel, Jerry R.; Hult, Dane W.; Koski, Katrina; Depue, Tracy; Cuellar, Edward L.; Balfour, Jim; Roof, Morey; Yarger, Fred W.; Newlin, Greg; Ramzel, Lee; Buchanan, Peter; Mariam, Fesseha G.; Scotese, Lee

    2002-01-01

    The GEO Light Imaging National Testbed (GLINT) will use three laser beams producing simultaneous interference fringes to illuminate satellites in geosynchronous earth orbit (GEO). The reflected returns will be recorded using a large 4,000 m2 'light bucket' receiver. This imaging methodology is termed Fourier Telescopy. A major component of the 'light bucket' will be an array of 40 - 80 heliostats. Each heliostat will have a mirrored surface area of 100 m2 mounted on a rigid truss structure which is supported by an A-frame. The truss structure attaches to the torque tube elevation drive and the A-frame structure rests on an azimuth ring that could provide nearly full coverage of the sky. The heliostat is designed to operate in 15 mph winds with jitter of less than 500 microradians peak-to- peak. One objective of the design was to minimize receiver cost to the maximum extent possible while maintaining GLINT system performance specifications. The mechanical structure weights approximately seven tons and is a simple fabricated steel framework. A prototype heliostat has been assembled at Stallion Range Center, White Sands Missile Range, New Mexico and is being tested under a variety of weather and operational conditions. The preliminary results of that testing will be presented as well as some finite element model analyses that were performed to predict the performance of the structure.

  11. Situation fencing: making geo-fencing personal and dynamic

    OpenAIRE

    Pongpaichet, Siripen; Singh, Vivek Kumar; Jain, Ramesh; Pentland, Alex Paul

    2013-01-01

    Geo-fencing has recently been applied to multiple applications including media recommendation, advertisements, wildlife monitoring, and recreational activities. However current geo-fencing systems work with static geographical boundaries. Situation Fencing allows for these boundaries to vary automatically based on situations derived by a combination of global and personal data streams. We present a generic approach for situation fencing, and demonstrate how it can be operationalized in practi...

  12. geoSDI: dal GIS allo scenario Web Shared

    Directory of Open Access Journals (Sweden)

    Dimitri Dello Buono

    2010-03-01

    Full Text Available geoSDI: from GIS to web shared scenariosA year ago we discussed about the use of geoSDI suite, developedby the IMAA CNR - Center of Competence for the SDI, Spatial Data Infrastructure of the Department of Civil Defense, during the post-earthquake emergency in Abruzzo and then use the system during the G8 summit which took place just in L'Aquila in July 2009. In this article the update of the situation.

  13. Multi-User GeoGebra for Virtual Math Teams

    Directory of Open Access Journals (Sweden)

    Gerry Stahl

    2010-05-01

    Full Text Available The Math Forum is an online resource center for pre-algebra, algebra, geometry and pre-calculus. Its Virtual Math Teams (VMT service provides an integrated web-based environment for small teams to discuss mathematics. The VMT collaboration environment now includes the dynamic mathematics application, GeoGebra. It offers a multi-user version of GeoGebra, which can be used in concert with VMT’s chat, web browsers, curricula and wiki repository.

  14. RSS as a distribution medium for geo-spatial hypermedia

    DEFF Research Database (Denmark)

    Hansen, Frank Allan; Christensen, Bent Guldbjerg; Bouvin, Niels Olof

    2005-01-01

    This paper describes how the XML based RSS syndication formats used in weblogs can be utilized as the distribution medium for geo-spatial hypermedia, and how this approach can be used to create a highly distributed multi-user annotation system for geo-spatial hypermedia. It is demonstrated, how...... the HyCon annotation model [2] can be formulated as a RSS 2.0 feed and how such feeds allow annotation threads to be distributed across multiple weblogs and servers....

  15. Strategies GeoCape Intelligent Observation Studies @ GSFC

    Science.gov (United States)

    Cappelaere, Pat; Frye, Stu; Moe, Karen; Mandl, Dan; LeMoigne, Jacqueline; Flatley, Tom; Geist, Alessandro

    2015-01-01

    This presentation provides information a summary of the tradeoff studies conducted for GeoCape by the GSFC team in terms of how to optimize GeoCape observation efficiency. Tradeoffs include total ground scheduling with simple priorities, ground scheduling with cloud forecast, ground scheduling with sub-area forecast, onboard scheduling with onboard cloud detection and smart onboard scheduling and onboard image processing. The tradeoffs considered optimzing cost, downlink bandwidth and total number of images acquired.

  16. A Modified Hansen's Theory as Applied to the Motion of Artificial Satellites

    Science.gov (United States)

    Musen, Peter

    1960-01-01

    This report presents a theory of oblateness perturbations of the orbits of artificial satellites based on Hansen's theory, with modification for adaptation to fast machine computation. The theory permits the easy inclusion of any gravitational terms and is suitable for the deduction of geo-physical and geodetic data from orbit observations on artificial satellites. The computations can be carried out to any desired order compatible with the accuracy of the geodetic parameters.

  17. Use of Advanced Solar Cells for Commercial Communication Satellites

    Science.gov (United States)

    Bailey, Sheila G.; Landis, Geoffrey A.

    1995-01-01

    The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

  18. Dependent surveillance through an experimental satellite data link system

    Science.gov (United States)

    Cobley, G. A.

    The development and testing of an experimental dependent aircraft-surveillance system using a satellite data link is reported. In this system, the aircraft position is determined onboard using GPS or inertial navigation, enclosed in a message block using a data-link system, and transmitted to an Inmarsat GEO communication satellites; the ground station receives and analyzes the data to keep constant track of the aircraft position. The hardware implementation and the results of demonstrations performed on flights from Iowa to Wisconsin and the North Atlantic are discussed, and diagrams and maps are provided.

  19. NUMERICAL INTEGRATION OF A SATELLITE ORBIT WITH KS TRANSFORMATION

    OpenAIRE

    Piñeros, Jhonathan Murcia; Koffi, Maxime; Kuga, Helio Koiti

    2017-01-01

    A satellite orbit is mainly influenced by central body gravitational forces. For a satellite in LEO (Low Earth Orbit), MEO (Medium Earth Orbit) or GEO (Geosynchronous Earth Orbit) the Earth´s gravity distribution and other perturbations determine the position and velocity changes in function of time. If the motion is around a spherical body with homogenous mass distribution and without perturbative forces, the orbit must be cyclic like the Two Body Problem (TBP) or Keplerian Orbit. Different ...

  20. GeoCARB design maturity and geostationary heritage

    Science.gov (United States)

    Sawyer, Kevin; Clark, Charles; Katz, Noah; Kumar, Jack; Nast, Ted; Palmer, Alice

    2013-09-01

    Our companion paper `Progress in development of Tropospheric Infrared Mapping Spectrometers (TIMS): geostationary greenhouse gas (GHG) application' describes geoCARB performance and science. Here we describe a geoCARB instrument design study leading to near PDR maturity. It is based on heritage geostationary (AIA and HMI on SDO, SBIRS GEO-1 and upcoming GLM on GOES-R as examples) and other (IRIS and NIRcam) flight instrumentation. Heritage work includes experience and well developed specifications for near a-thermal carbon fiber honeycomb composite optical benches and optical element mounting design forms that utilize a "family" of mounts for nearly any type of optical element. The geoCARB approach utilizes composite optical benches and bipod flexures to kinematically mount optics. Tooling for alignment and staking of all elements is integral to the design and is "removed before flight" for mass minimization. GeoCARB requires a cryogenic region for focal planes and spectrometers but front end optics and main structure are designed to run much warmer. A star tracker is used for geoCARB posteriori geolocation including pseudo-diurnal thermal distortion characterization. It is kinematically mounted by low conductance thermal isolators directly on to the low expansion high stiffness composite bench that defines the master optical surfaces including the scanning mirrors. The thermal load from the camera heads is routed away from the bench heat pipes. Use of kinematic mounting is advantageous for low thermal conduction designs. Honeycomb composites enable the design's low thermal mechanical distortions.

  1. GeoCSV: tabular text formatting for geoscience data

    Science.gov (United States)

    Stults, M.; Arko, R. A.; Davis, E.; Ertz, D. J.; Turner, M.; Trabant, C. M.; Valentine, D. W., Jr.; Ahern, T. K.; Carbotte, S. M.; Gurnis, M.; Meertens, C.; Ramamurthy, M. K.; Zaslavsky, I.; McWhirter, J.

    2015-12-01

    The GeoCSV design was developed within the GeoWS project as a way to provide a baseline of compatibility between tabular text data sets from various sub-domains in geoscience. Funded through NSF's EarthCube initiative, the GeoWS project aims to develop common web service interfaces for data access across hydrology, geodesy, seismology, marine geophysics, atmospheric science and other areas. The GeoCSV format is an essential part of delivering data via simple web services for discovery and utilization by both humans and machines. As most geoscience disciplines have developed and use data formats specific for their needs, tabular text data can play a key role as a lowest common denominator useful for exchanging and integrating data across sub-domains. The design starts with a core definition compatible with best practices described by the W3C - CSV on the Web Working Group (CSVW). Compatibility with CSVW is intended to ensure the broadest usability of data expressed as GeoCSV. An optional, simple, but limited metadata description mechanism was added to allow inclusion of important metadata with comma separated data, while staying with the definition of a "dialect" by CSVW. The format is designed both for creating new datasets and to annotate data sets already in a tabular text format such that they are compliant with GeoCSV.

  2. GeoNode condivisione di dati e applicazioni territoriali

    Directory of Open Access Journals (Sweden)

    Simone Dalmasso

    2012-04-01

    Full Text Available Negli ultimi anni si è passati da un sistema in cui la priorità era reperire le informazioni ad un sistema in cui la priorità è gestire l’imponente mole di dati disponibili e soprattutto rendere questi dati utili, cioè condividerli pensando anche ad un’utenza non necessariamente tecnica. GeoNode  sharing  of  spatial  data  and land applicationsGeoNode is an open source platform that facilitates the creation, sharing, and collab-orative use of geospatial data. The project aims to surpass existing spatial data infra-structure  solutions  by  integrating  robust social and cartographic tools.At its core, the GeoNode has a stack based on  GeoServer,  Django,  and  GeoExt  that provides a platform for sophisticated web browser  spatial  visualization  and  analysis (excerpt from GeoNode website.

  3. NCBI GEO: archive for high-throughput functional genomic data.

    Science.gov (United States)

    Barrett, Tanya; Troup, Dennis B; Wilhite, Stephen E; Ledoux, Pierre; Rudnev, Dmitry; Evangelista, Carlos; Kim, Irene F; Soboleva, Alexandra; Tomashevsky, Maxim; Marshall, Kimberly A; Phillippy, Katherine H; Sherman, Patti M; Muertter, Rolf N; Edgar, Ron

    2009-01-01

    The Gene Expression Omnibus (GEO) at the National Center for Biotechnology Information (NCBI) is the largest public repository for high-throughput gene expression data. Additionally, GEO hosts other categories of high-throughput functional genomic data, including those that examine genome copy number variations, chromatin structure, methylation status and transcription factor binding. These data are generated by the research community using high-throughput technologies like microarrays and, more recently, next-generation sequencing. The database has a flexible infrastructure that can capture fully annotated raw and processed data, enabling compliance with major community-derived scientific reporting standards such as 'Minimum Information About a Microarray Experiment' (MIAME). In addition to serving as a centralized data storage hub, GEO offers many tools and features that allow users to effectively explore, analyze and download expression data from both gene-centric and experiment-centric perspectives. This article summarizes the GEO repository structure, content and operating procedures, as well as recently introduced data mining features. GEO is freely accessible at http://www.ncbi.nlm.nih.gov/geo/.

  4. Towards Autonomous Modular UAV Missions: The Detection, Geo-Location and Landing Paradigm.

    Science.gov (United States)

    Kyristsis, Sarantis; Antonopoulos, Angelos; Chanialakis, Theofilos; Stefanakis, Emmanouel; Linardos, Christos; Tripolitsiotis, Achilles; Partsinevelos, Panagiotis

    2016-11-03

    Nowadays, various unmanned aerial vehicle (UAV) applications become increasingly demanding since they require real-time, autonomous and intelligent functions. Towards this end, in the present study, a fully autonomous UAV scenario is implemented, including the tasks of area scanning, target recognition, geo-location, monitoring, following and finally landing on a high speed moving platform. The underlying methodology includes AprilTag target identification through Graphics Processing Unit (GPU) parallelized processing, image processing and several optimized locations and approach algorithms employing gimbal movement, Global Navigation Satellite System (GNSS) readings and UAV navigation. For the experimentation, a commercial and a custom made quad-copter prototype were used, portraying a high and a low-computational embedded platform alternative. Among the successful targeting and follow procedures, it is shown that the landing approach can be successfully performed even under high platform speeds.

  5. Towards Autonomous Modular UAV Missions: The Detection, Geo-Location and Landing Paradigm

    Directory of Open Access Journals (Sweden)

    Sarantis Kyristsis

    2016-11-01

    Full Text Available Nowadays, various unmanned aerial vehicle (UAV applications become increasingly demanding since they require real-time, autonomous and intelligent functions. Towards this end, in the present study, a fully autonomous UAV scenario is implemented, including the tasks of area scanning, target recognition, geo-location, monitoring, following and finally landing on a high speed moving platform. The underlying methodology includes AprilTag target identification through Graphics Processing Unit (GPU parallelized processing, image processing and several optimized locations and approach algorithms employing gimbal movement, Global Navigation Satellite System (GNSS readings and UAV navigation. For the experimentation, a commercial and a custom made quad-copter prototype were used, portraying a high and a low-computational embedded platform alternative. Among the successful targeting and follow procedures, it is shown that the landing approach can be successfully performed even under high platform speeds.

  6. Assimilation of Precipitation Measurement Missions Microwave Radiance Observations With GEOS-5

    Science.gov (United States)

    Jin, Jianjun; Kim, Min-Jeong; McCarty, Will; Akella, Santha; Gu, Wei

    2015-01-01

    The Global Precipitation Mission (GPM) Core Observatory satellite was launched in February, 2014. The GPM Microwave Imager (GMI) is a conically scanning radiometer measuring 13 channels ranging from 10 to 183 GHz and sampling between 65 S 65 N. This instrument is a successor to the Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI), which has observed 9 channels at frequencies ranging 10 to 85 GHz between 40 S 40 N since 1997. This presentation outlines the base procedures developed to assimilate GMI and TMI radiances in clear-sky conditions, including quality control methods, thinning decisions, and the estimation of, observation errors. This presentation also shows the impact of these observations when they are incorporated into the GEOS-5 atmospheric data assimilation system.

  7. A virtual reference satellite differential method for relative correction of satellite ephemeris errors

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to solve the problems that the novel wide area differential method on the satellite clock and ephemeris relative correction (CERC) in the non-geostationary orbit satellite constellation, a virtual reference satellite (VRS) differential principle using relative correction of satellite ephemeris errors is proposed. It is referred to be as the VRS differential principle, and the elaboration is focused on the construction of pseudo-range errors of VRS. Through qualitative analysis, it can be found that the impact of the satellite’s clock and ephemeris errors on positioning can basically be removed and the users’ positioning errors are near zero. Through simulation analysis of the differential performance, it is verified that the differential method is universal in all kinds of satellite navigation systems with geostationary orbit (GEO) constellation, Medium orbit (MEO) constellation or hybrid orbit constellation, and it has insensitivity to abnormal aspects of a satellite ephemeris and clock. Moreover, the real time positioning accuracy of differential users can be maintained within several decimeters after the pseudo-range measurement noise is effectively weakened or eliminated.

  8. The story of DB4GeO - A service-based geo-database architecture to support multi-dimensional data analysis and visualization

    Science.gov (United States)

    Breunig, Martin; Kuper, Paul V.; Butwilowski, Edgar; Thomsen, Andreas; Jahn, Markus; Dittrich, André; Al-Doori, Mulhim; Golovko, Darya; Menninghaus, Mathias

    2016-07-01

    Multi-dimensional data analysis and visualization need efficient data handling to archive original data, to reproduce results on large data sets, and to retrieve space and time partitions just in time. This article tells the story of more than twenty years research resulting in the development of DB4GeO, a web service-based geo-database architecture for geo-objects to support the data handling of 3D/4D geo-applications. Starting from the roots and lessons learned, the concepts and implementation of DB4GeO are described in detail. Furthermore, experiences and extensions to DB4GeO are presented. Finally, conclusions and an outlook on further research also considering 3D/4D geo-applications for DB4GeO in the context of Dubai 2020 are given.

  9. GeoIRIS: Geospatial Information Retrieval and Indexing System-Content Mining, Semantics Modeling, and Complex Queries.

    Science.gov (United States)

    Shyu, Chi-Ren; Klaric, Matt; Scott, Grant J; Barb, Adrian S; Davis, Curt H; Palaniappan, Kannappan

    2007-04-01

    Searching for relevant knowledge across heterogeneous geospatial databases requires an extensive knowledge of the semantic meaning of images, a keen eye for visual patterns, and efficient strategies for collecting and analyzing data with minimal human intervention. In this paper, we present our recently developed content-based multimodal Geospatial Information Retrieval and Indexing System (GeoIRIS) which includes automatic feature extraction, visual content mining from large-scale image databases, and high-dimensional database indexing for fast retrieval. Using these underpinnings, we have developed techniques for complex queries that merge information from heterogeneous geospatial databases, retrievals of objects based on shape and visual characteristics, analysis of multiobject relationships for the retrieval of objects in specific spatial configurations, and semantic models to link low-level image features with high-level visual descriptors. GeoIRIS brings this diverse set of technologies together into a coherent system with an aim of allowing image analysts to more rapidly identify relevant imagery. GeoIRIS is able to answer analysts' questions in seconds, such as "given a query image, show me database satellite images that have similar objects and spatial relationship that are within a certain radius of a landmark."

  10. Auto-Scaling of Geo-Based Image Processing in an OpenStack Cloud Computing Environment

    Directory of Open Access Journals (Sweden)

    Sanggoo Kang

    2016-08-01

    Full Text Available Cloud computing is a base platform for the distribution of large volumes of data and high-performance image processing on the Web. Despite wide applications in Web-based services and their many benefits, geo-spatial applications based on cloud computing technology are still developing. Auto-scaling realizes automatic scalability, i.e., the scale-out and scale-in processing of virtual servers in a cloud computing environment. This study investigates the applicability of auto-scaling to geo-based image processing algorithms by comparing the performance of a single virtual server and multiple auto-scaled virtual servers under identical experimental conditions. In this study, the cloud computing environment is built with OpenStack, and four algorithms from the Orfeo toolbox are used for practical geo-based image processing experiments. The auto-scaling results from all experimental performance tests demonstrate applicable significance with respect to cloud utilization concerning response time. Auto-scaling contributes to the development of web-based satellite image application services using cloud-based technologies.

  11. The SmartGeo Portal: A retrospective

    Science.gov (United States)

    Heilmann, Zeno; Satta, Guido; Bonomi, Ernesto

    2016-04-01

    The SmartGeo portal was created in a follow-up project that evolved from the geophysical data imaging services of a Grid computing portal for Geoscience, called GRIDA3. The scope of the project was to support commercial geotechnical service providers as well as academic researchers working in near-surface geoscience. Starting from the existing services, the SmartGeo portal was set up on new hardware, using the latest version of the grid portal environment EnginFrame. After a first working version was established, the services were reviewed, updated and accompanied by new services according to the feedback we received from our partners. One partner for instance experienced large difficulties in a project that aimed at delineating the aquifer for finding water pollutant substances in an industrial area of Basel. The seismic imaging service inherited from the previous portal was employing a data-driven algorithm optimized to provide, directly during data acquisition, nearly in real-time a first image of the subsurface structure. Different to this, our user needed for his data from a geologically very complex and noisy urban environment the maximum lateral resolution and noise reduction possible. For this purpose we added two cutting edge data imaging algorithms able to deliver such high precision results by simultaneously optimizing, for every single image point, all parameters of the mathematical model---a procedure which increased the computational effort by one or two magnitudes, respectively. Thus, parallel computing on grid infrastructure served for maximizing the image resolution instead for generating real-time results. This proved also very useful for the data of an academic partner, recorded for imaging the structure of a shallow sedimentary basin, where we could obtain strongly improved seismic velocity information using these new algorithms. A general user request was to implement interactive data visualization tools. To fulfill this demand we took

  12. Towards a standardized grasping and refuelling on-orbit servicing for geo spacecraft

    Science.gov (United States)

    Medina, Alberto; Tomassini, Angelo; Suatoni, Matteo; Avilés, Marcos; Solway, Nick; Coxhill, Ian; Paraskevas, Iosif S.; Rekleitis, Georgios; Papadopoulos, Evangelos; Krenn, Rainer; Brito, André; Sabbatinelli, Beatrice; Wollenhaupt, Birk; Vidal, Christian; Aziz, Sarmad; Visentin, Gianfranco

    2017-05-01

    Exploitation of space must benefit from the latest advances in robotics. On-orbit servicing is a clear candidate for the application of autonomous rendezvous and docking mechanisms. However, during the last three decades most of the trials took place combining extravehicular activities (EVAs) with telemanipulated robotic arms. The European Space Agency (ESA) considers that grasping and refuelling are promising near-mid-term capabilities that could be performed by servicing spacecraft. Minimal add-ons on spacecraft to enhance their serviceability may protect them for a changing future in which satellite servicing may become mainstream. ESA aims to conceive and promote standard refuelling provisions that can be installed in present and future European commercial geostationary orbit (GEO) satellite platforms and scientific spacecraft. For this purpose ESA has started the ASSIST activity addressing the analysis, design and validation of internal provisions (such as modifications to fuel, gas, electrical and data architecture to allow servicing) and external provisions (such as integrated berthing fixtures with peripheral electrical, gas, liquid connectors, leak check systems and corresponding optical and radio markers for cooperative rendezvous and docking). This refuelling approach is being agreed with European industry (OHB, Thales Alenia Space) and expected to be consolidated with European commercial operators as a first step to become an international standard; this approach is also being considered for on-orbit servicing spacecraft, such as the SpaceTug, by Airbus DS. This paper describes in detail the operational means, structure, geometry and accommodation of the system. Internal and external provisions will be designed with the minimum possible impact on the current architecture of GEO satellites without introducing additional risks in the development and commissioning of the satellite. End-effector and berthing fixtures are being designed in the range of few

  13. Application of Geo-Spatial Techniques for Precise Demarcation of Village/Panchayat Boundaries

    Science.gov (United States)

    Rao, S. S.; Banu, V.; Tiwari, A.; Bahuguna, S.; Uniyal, S.; Chavan, S. B.; Murthy, M. V. R.; Arya, V. S.; Nagaraja, R.; Sharma, J. R.

    2014-11-01

    In order to achieve the overall progress of the country with active and effective participation of all sections of society, the 12th Five Year Plan (FYP) would bring Panchayats centre-stage and achieve the inclusive growth agenda through inclusive governance. The concept of 'democratic decentralization' in the form of a three-tier administration was introduced in the name of "Panchayat Raj". Horizontally, it is a network of village Panchayats. Vertically, it is an organic growth of Panchayats rising up to national level. The Ministry of Panchayati Raj has three broad agenda: Empowerment, Enablement and Accountability. Space based Information Support for Decentralized Planning (SIS-DP) is one of the initiatives taken by Govt. of India with ISRO/DOS for generation and dissemination of spatial information for planning at the grass root level. The boundary layer for villages across different states/district/block is available with line departments. Most of these data exist at a much generalized scale. These boundaries do not overlay exactly with that of ground realities and may not be suitable for accurate analysis in terms of area, shape, position, etc. To deal with this problem, a strategy is adopted, which makes use of High Resolution Satellite Imagery (HRSI) from Indian Remote sensing satellites and cadastral maps at 1:4000 scale integrated with GIS techniques to enhance the accuracy of geo-spatial depiction of Village/Panchayat boundaries. Cadastral maps are used to depict the boundaries of land parcels and other features at the village level. These maps are registered to ortho products of HRSI using Ground Control Points. The cadastral maps are precisely overlaid on ortho-rectified HRSI and each parcel vertex is tagged with the real-world geographical coordinates. Village boundaries are extracted from the geo-referenced village cadastral maps. These boundaries are fine-tuned by considering under lap and overlap of neighboring villages and a mosaic is generated at

  14. Modern geothermal power: GeoPP with geothermal steam turbines

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.

    2017-03-01

    The first part of the review presents information on the scale and specific features of geothermal energy development in various countries. The classification of geothermal power plant (GeoPP) process flow diagrams by a phase state of the primary heat source (a geothermal fluid), thermodynamic cycle, and applicable turbines is proposed. Features of geothermal plants using methods of flashing and steam separation in the process loop and a flowsheet and thermodynamic process of a geothermal fluid heat-to-power conversion in a GeoPP of the most widespread type using a double-flash separation are considered. It is shown that, for combined cycle power units, the specific power-to-consumption geothermal fluid ratio is 20-25% higher than that for traditional single-loop GeoPP. Information about basic chemical components and their concentration range for geothermal fluids of various formations around the world is presented. Three historic stages of improving geothermal energy technologies are determined, such as development of high-temperature geothermal resources (dry, superheated steam) and application of a two-phase wet-steam geothermal fluid in GeoPP power units with one or two expansion pressures and development of binary cycle GeoPPs. A current trend of more active use of binary power plants in GeoPP technological processes is noted. Design features of GeoPP's steam turbines and steam separating devices, determined by the use of low-potential geothermal saturated steam as a working medium, which is characterized by corrosion aggressiveness and a tendency to form deposits, are considered. Most promising Russian geothermal energy projects are determined. A list of today's most advanced geothermal turbine performance technologies is presented. By an example of a 25 MW steam turbine design, made by JSC Kaluga Turbine Works, advantages of the internal moisture separation with a special turbine-separator stage are shown.

  15. Methods of rapid orbit forecasting after maneuvers for geostationary satellites

    Institute of Scientific and Technical Information of China (English)

    YANG XuHai; LI ZhiGang; FENG ChuGang; GUO Ji; SHI HuLi; AI GuoXiang; WU FengLei; QIAO RongChuan

    2009-01-01

    A geostationary (GEO) satellite may serve as a navigation satellite,but there is a problem that maneuvers frequently occur and the forces are difficult to model.Based on the technique of determining setellite orbits by transfer,a predicted orbit with high accuracy may be achieved by the method of statistical orbit determination in case of no maneuver force.The predicted orbit will soon be invalid after the maneuver starts,and it takes a long time to get a valid orbit after the maneuver ends.In order to improve ephemeris usability,the method of rapid orbit forecasting after maneuvers is studied.First,GEO satellite movement is analyzed in case of maneuvers based on the observation from the orbit measurement system by transfer.Then when a GEO satellite is in the free status just after maneuvers,the short arc observation is used to forecast the orbit.It is assumed that the common system bias and biases of each station are constant,which can be obtained from orbit determination with long arc observations.In this way,only 6 orbit elements would be solved by the method of statistical orbit determination,and the ephemeris with high accuracy may be soon obtained.Actual orbit forecasting with short arc observation for SlNOSAT-1 satellite shows that,with the tracking network available,the precision of the predicted orbit (RMS of O-C) can reach about 5 m with 15 min arc observation,and about 3 m with 30 min arc observation.

  16. GEO与NGEO卫星频谱共存干扰抑制技术(一)%Coexistence and Interference Mitigation between NGEO and GEO(I)

    Institute of Scientific and Technical Information of China (English)

    曾昱祺; 杨夏青

    2016-01-01

    Due to the increasing demand for low latency real-time systems and broadband data,people pay more attention to how to deploy more Low Earth Orbit(LEO) and Medium Earth Orbit(MEO) satellites in several available frequency bands. When the number of available Non-Geostationary Earth Orbit(NGEO,i.e.,LEO/MEO) satellites increases,It has become a must for the spectrum coexistence between the NGEO satellites with the Geostationary Orbit(GEO) satellites in orbit. In this context,it is crucial to explore interference mitigation techniques between GEO and NGEO systems in order to allow their spectral coexistence. More specifically,in the coexistence scenario of GEO and NGEO satellite networks,in-line interference may be a serious problem,especially in the equatorial region. In this paper,we provide several frequency sharing studies in the context of the coexistence of an NGEO satellite link with another NGEO/GEO satellite link. Moreover,we suggest several cognitive solutions for mitigating the in-line interference and provide future research issues.%由于对低延时实时系统和宽带数据的需求日益增加,人们越来越关注如何在几个可用的频带中部署更多的近地轨道(LEO)和中地轨道(MEO)卫星。当可用的非静止轨道(NGEO,即LEO/MEO)卫星数目增多时,其与在轨的地球静止轨道(GEO)卫星频谱共存已经成为了一种必须。在这种情况下,为了使它们的频谱可以共用,探索一项技术来抑制GEO和NGEO系统间的干扰是非常关键的。更具体地说,在GEO和NGEO卫星网络共存的情况下,共线干扰可能是一个严重的问题,特别是在赤道上空。本文提供了几个关于如何在NGEO卫星链路和GEO卫星链路共存情况下频率共用的研究。除此之外,本文提出了几种认知方法来解决共线干扰,也提出了未来研究方向。

  17. The Group on Earth Observations (GEO) through 2025

    Science.gov (United States)

    Ryan, Barbara; Cripe, Douglas

    Ministers from the Group on Earth Observations (GEO) Member governments, meeting in Geneva, Switzerland in January 2014, unanimously renewed the mandate of GEO through 2025. Through a Ministerial Declaration, they reconfirmed that GEO’s guiding principles of collaboration in leveraging national, regional and global investments and in developing and coordinating strategies to achieve full and open access to Earth observations data and information in order to support timely and knowledge-based decision-making - are catalysts for improving the quality of life of people around the world, advancing global sustainability, and preserving the planet and its biodiversity. GEO Ministers acknowledged and valued the contributions of GEO Member governments and invited all remaining Member States of the United Nations to consider joining GEO. The Ministers also encouraged all Members to strengthen national GEO arrangements, and - of particular interest to COSPAR - they highlighted the unique contributions of Participating Organizations. In this regard, ten more organizations saw their applications approved by Plenary and joined the ranks along with COSPAR to become a Participating Organization in GEO, bringing the current total to 77. Building on the efforts of a Post-2015 Working Group, in which COSPAR participated, Ministers provided additional guidance for GEO and the evolution of its Global Earth Observation System of System (GEOSS) through 2025. Five key areas of activities for the next decade include the following: 1.) Advocating for the value of Earth observations and the need to continue improving Earth observation worldwide; 2.) Urging the adoption and implementation of data sharing principles globally; 3.) Advancing the development of the GEOSS information system for the benefit of users; 4.) Developing a comprehensive interdisciplinary knowledge base defining and documenting observations needed for all disciplines and facilitate availability and accessibility of

  18. 地球信息图谱与数字地球%On Geo-informatic TuPu and Digital Earth

    Institute of Scientific and Technical Information of China (English)

    廖克; 秦建新; 张青年

    2001-01-01

    Digital Earth can be understood as digitized reoresentation and the recognition for real earth and related, geo-phenomena. Digital Earth consists of spatial information with different levels and application models with different objectives. It includes the establishment of base and thematic digital maps with global, national, regional and urban scales, and satellite image data with different resolution and various geo-informations such as population, economy, society and their application systems.   Geo-informatic TuPu, as graphic representation of spatio-temporal change of geo-information, is an effective tool for the application of Digital Earth. “Tu”, in Chinese word, includes graphics, maps and images. The Chinese word “Pu” means the well-regulated sequence arrangement of the congener things, such as spectrum, chromatogram. “TuPu” involves the characteristics of “Tu” and “Pu” at the same time.   Geo-information TuPu can not only reflect spatial distribution characteristics of geo-phenomena and regional differences between them, but also reveal the deeper level rules related to the cause of formation, the process of evolution and morphology. Having the aid of computer visualization and Virtual Reality technology, TuPu can dynamically and muti-dimensionally reveal the spatial-temporal distribution and evolvement laws of all kinds of geo-phenomena.   In this paper, the technological system of Digital Earth and its significance, and the concept of Geo-informatic TuPu are discussed firstly, then, the model of Geo-informatic TuPu transmission is presented. On the basis of the above-mentioned researches, the relationship between Digital Earth and Geo-informatic TuPu is discussed. It reaches to the conclusion that the development of Digital Earth will provide with abundant information resources and strong technological support for Geo-informatic TuPu researches, and the enforcement of Digital Earth strategy will supply Geo-informatic Tu

  19. Benefits of using Open Geo-spatial Data for valorization of Cultural Heritage: GeoPan app

    Science.gov (United States)

    Cuca, Branka; Previtali, Mattia; Barazzetti, Luigi; Brumana, Raffaella

    2017-04-01

    Experts evaluate the spatial data to be one of the categories of Public Sector Information (PSI), of which the exchange is particularly important. On the other side an initiative with a great vision such as Digital Agenda for Europe, emphasizes on intelligent processing of information as essential factor for tackling the challenges of the contemporary society. In such context, the Open Data are considered to be crucial in addressing, environmental pressures, energy efficiency issues, land use and climate change, pollution and traffic management. Furthermore, Open Data are thought to have an important impact on more informed decision making and policy creation for multiple domains that could be addressed even through "apps" of our smart devices. Activities performed in ENERGIC OD project - "European NEtwork for Redistributing Geospatial Information to user Communities - Open Data" have led to some first conclusions on the use and re-use of geo-spatial Open Data by means of Virtual Hubs - an innovative method for brokering of geo-spatial information. This paper illustrates some main benefits of using Open Geo-spatial Data for valorisation of Cultural Heritage through a case of an innovative app called "GeoPan Atl@s". GeoPan, inserted in a dynamic policy context described, aims to provide all information valuable for a sustainable territorial development in a common platform, in particular the material that regards history and changes of the cultural landscapes in Lombardy region. Furthermore, this innovative app is used as a test-bed to facilitate and encourage a more active exchange and exploitation of open geo-spatial information for purposes of valorisation of cultural heritage and landscapes. The aim of this practice is also to achieve a more active participation of experts, VGI communities and citizens and a higher awareness of the multiple use-possibilities of historic and contemporary geo-spatial information for smarter decision making.

  20. D Geo-Information Requirements for Disaster and Emergency Management

    Science.gov (United States)

    Demir Ozbek, E.; Zlatanova, S.; Ates Aydar, S.; Yomralioglu, T.

    2016-06-01

    A conceptual approach is proposed to define 3D geo-information requirement for different types of disasters. This approach includes components such as Disaster Type-Sector-Actor-Process-Activity-Task-Data. According to disaster types processes, activities, tasks, sectors, and responsible and operational actors are derived. Based on the tasks, the needed level of detail for 3D geo-information model is determined. The levels of detail are compliant with the 3D international standard CityGML. After a brief introduction on the disaster phases and geo-information requirement for actors to perform the tasks, the paper discusses the current situation of disaster and emergency management in Turkey and elaborates on components of conceptual approach. This paper discusses the 3D geo-information requirements for the tasks to be used in the framework of 3D geo-information model for Disaster and Emergency Management System in Turkey. The framework is demonstrated for an industrial fire case in Turkey.

  1. Thallium pollution in China: A geo-environmental perspective.

    Science.gov (United States)

    Xiao, Tangfu; Yang, Fei; Li, Shehong; Zheng, Baoshan; Ning, Zengping

    2012-04-01

    It is well known that thallium (Tl) is a non-essential and toxic metal to human health, but less is known about the geo-environmentally-induced Tl pollution and its associated health impacts. High concentrations of Tl that are primarily associated with the epithermal metallogenesis of sulfide minerals have the potential of producing Tl pollution in the environment, which has been recognized as an emerging pollutant in China. This paper aims to review the research progress in China on Tl pollution in terms of the source, mobility, transportation pathway, and health exposure of Tl and to address the environmental concerns on Tl pollution in a geo-environmental perspective. Tl associated with the epithermal metallogenesis of sulfide minerals has been documented to disperse readily and accumulate through the geo-environmental processes of soil enrichment, water transportation and food crop growth beyond a mineralized zone. The enrichments of Tl in local soil, water, and crops may result in Tl pollution and consequent adverse health effects, e.g. chronic Tl poisoning. Investigation of the baseline Tl in the geo-environment, proper land use and health-related environmental planning and regulation are critical to prevent the Tl pollution. Examination of the human urinary Tl concentration is a quick approach to identify exposure of Tl pollution to humans. The experiences of Tl pollution in China can provide important lessons for many other regions in the world with similar geo-environmental contexts because of the high mobility and toxicity of Tl.

  2. Geo-ontology design and its logic reasoning

    Science.gov (United States)

    Wang, Yandong; Dai, Jingjing; Sheng, Jizhen; Zhou, Kai; Gong, Jianya

    2007-06-01

    With the increasing application of geographic information system (GIS), GIS is faced with the difficulty of efficient management and comprehensive application of the spatial information from different resources and in different forms. In order to solve these problems, ontology is introduced into GIS field as a concept model which can represent object on semantic and knowledge level. Ontology not only can describe spatial data more easily understood by computers in semantic encoding method, but also can integrate geographical data from different sources and in different forms for reasoning. In this paper, a geo-ontology "GeographicalSpace" is built with Web Ontology Language (OWL) after analyzing the research and application of geo-ontology. A geo-ontology reasoning framework is put forward in which three layers are designed. The three layers are presentation layer, semantic service layer and spatial application server layer. By using the geo-ontology repository module and reasoning module in this framework, some more complex spatial location relationships in depth can be mined out. At last, an experiment is designed to demonstrate geo-ontology's ability to execute more intelligent query that can't be implemented in traditional GIS.

  3. Geo-neutrinos: A systematic approach to uncertainties and correlations

    CERN Document Server

    Fogli, G L; Palazzo, A; Rotunno, A M

    2006-01-01

    Geo-neutrinos emitted by heat-producing elements (U, Th and K) represent a unique probe of the Earth interior. The characterization of their fluxes is subject, however, to rather large and highly correlated uncertainties. The geochemical covariance of the U, Th and K abundances in various Earth reservoirs induces positive correlations among the associated geo-neutrino fluxes, and between these and the radiogenic heat. Mass-balance constraints in the Bulk Silicate Earth (BSE) tend instead to anti-correlate the radiogenic element abundances in complementary reservoirs. Experimental geo-neutrino observables may be further (anti)correlated by instrumental effects. In this context, we propose a systematic approach to covariance matrices, based on the fact that all the relevant geo-neutrino observables and constraints can be expressed as linear functions of the U, Th and K abundances in the Earth's reservoirs (with relatively well-known coefficients). We briefly discuss here the construction of a tentative "geo-neu...

  4. On safe ground? Analysis of European urban geohazards using satellite radar interferometry

    Science.gov (United States)

    Capes, Renalt; Teeuw, Richard

    2017-06-01

    Urban geological hazards involving ground instability can be costly, dangerous, and affect many people, yet there is little information about the extent or distribution of geohazards within Europe's urban areas. A reason for this is the impracticality of measuring ground instability associated with the many geohazard processes that are often hidden beneath buildings and are imperceptible to conventional geological survey detection techniques. Satellite radar interferometry, or InSAR, offers a remote sensing technique to map mm-scale ground deformation over wide areas given an archive of suitable multi-temporal data. The EC FP7 Space project named PanGeo (2011-2014), used InSAR to map areas of unstable ground in 52 of Europe's cities, representing ∼15% of the EU population. In partnership with Europe's national geological surveys, the PanGeo project developed a standardised geohazard-mapping methodology and recorded 1286 instances of 19 types of geohazard covering 18,000 km2. Presented here is an analysis of the results of the PanGeo-project output data, which provides insights into the distribution of European urban geohazards, their frequency and probability of occurrence. Merging PanGeo data with Eurostat's GeoStat data provides a systematic estimate of population exposures. Satellite radar interferometry is shown to be as a valuable tool for the systematic detection and mapping of urban geohazard phenomena.

  5. Analysis on BDS Satellite Internal Multipath and Its Impact on Wide-lane FCB Estimation

    Directory of Open Access Journals (Sweden)

    RUAN Rengui

    2017-08-01

    Full Text Available To the issue of the satellite internal multipath (SIMP of BeiDou satellites, it proposed and emphasized that the SIMP model should be established as a function of the nadir angle with respect to the observed satellite rather than the elevation of the measurement, so that it can be used for receivers at various altitude. BDS data from global distributed stations operated by the International Monitoring and Assessment System (iGMAS and the Multi-GNSS Experiment (MGEX of the International GNSS Service (IGS are collected and a new SIMP model as a piece-wise linear function of the nadir angle is released for the IGSO-and MEO-satellite groups and for B1, B2 and B3 frequency band individually. The SIMP of GEO,IGSO and MEO satellites is further analyzed with B1/B2 dual-frequency data onboard the FengYun-3 C(FY3C satellite at an altitude of~830 km, and it showed that, for nadir angles smaller than 7°, the SIMP values for GEO is quite close to the IGSO's, especially for B2, which may suggest that the SIMP model for IGSO satellites possibly also works for GEO satellites. It also demonstrated that, when the nadir angle is smaller than 12°for the MEO and 7°for the IGSO, the estimated SIMP model with data from FY3C is considerable consistent with that estimated with data collected at ground stations. Experiments are carried out to investigate the impacts of the SIMP on wide-lane fractional cycle bias (FCB estimation for BDS satellites. The result indicates that, with the correction of the estimated SIMP, the repeatability of the FCB series is significantly improved by more than 60% for all satellites. Specifically, for the MEO and IGSO satellites, the repeatability is smaller than 0.05 cycle; the repeatability of 0.023 and 0.068 cycles achieved for GEO satellites C01 and C02 respectively with the estimated SIMP model for IGSO satellites.

  6. GeoPad and GeoPocket: Information Technology for Field Science Education

    Science.gov (United States)

    Knoop, P. A.; van der Pluijm, B.

    2006-12-01

    Over the past four years we have successfully incorporated and evaluated the use of field-based Information Technology (IT) in introductory through senior-level field courses offered at the University of Michigan's Camp Davis Geology Field Station, near Jackson, WY. The use of GeoPads (field-durable Tablet PCs) and GeoPockets (field-durable Pocket PCs) -- both equipped with GIS, GPS, wireless networking, electronic notebook and other pertinent software -- have significantly enhanced our field exercises and excursions, for both students and instructors. We have focused on three main applications: (1) Mapping facilitating the development of spatial reasoning skills via powerful, intuitive capabilities for in-the-field data entry, visualization, analysis, and interpretation in both 2-D and 3-D representations; (2) Field-Trips enriching the overall experience by providing in-the-field access to a broad, relevant collection of supplemental materials, such as papers, figures, maps, photos, thin section images, etc.; and, (3) Field-Based Exercises enhancing the learning opportunities afforded by field-based exercises by supporting data analysis and interpretation, while still in the context in which the data was gathered. This IT-based approach to field education utilizes standard, off-the-shelf hardware and software, and provides students with experience using tools that are increasingly relevant to their future academic or professional careers. Furthermore, this approach is generally applicable to education and research in many traditionally non-IT-savvy science domains, in addition to geology, such as archeology, biology, sociology, and natural resources.

  7. A global comparison of GEOS-Chem predicted and remotely-sensed mineral dust aerosol optical depth

    Directory of Open Access Journals (Sweden)

    Matthew S Johnson

    2012-07-01

    Full Text Available Dust aerosol optical depth (AOD and vertical distribution of aerosol extinction predicted by a global chemical transport model (GEOS-Chem are compared to space-borne data from the Moderate-resolution Imaging Spectroradiometer (MODIS, Multi-Angle Imaging SpectroRadiometer (MISR, and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO for March 2009 to February 2010. Model-predicted and remotely-sensed AOD/aerosol extinction profiles are compared over six regions where aerosol abundances are dominated by mineral dust. Calculations indicate that over the regions examined in this study (with the exception of Middle Eastern dust sources GEOS-Chem predicts higher AOD values compared to MODIS and MISR. The positive bias is particularly pronounced over the Saharan dust source regions, where model-predicted AOD values are a factor of 2 to 3 higher. The comparison with CALIPSO-derived dust aerosol extinction profiles revealed that the model overestimations of dust abundances over the study regions primarily occur below ~4 km, suggesting excessive emissions of mineral dust and/or uncertainties in dust optical properties. The implementation of a new dust size distribution scheme into GEOS-Chem reduced the yearly-mean positive bias in model-predicted AOD values over the study regions. The results were most noticeable over the Saharan dust source regions where the differences between model-predicted and MODIS/MISR retrieved AOD values were reduced from 0.22 and 0.17 to 0.02 and -0.04, respectively. Our results suggest that positive/negative biases between satellite and model-predicted aerosol extinction values at different altitudes can sometimes even out, giving a false impression for the agreement between remotely-sensed and model-predicted column-integrated AOD data.

  8. The GEOS-3 orbit determination investigation

    Science.gov (United States)

    Pisacane, V. L.; Eisner, A.; Yionoulis, S. M.; Mcconahy, R. J.; Black, H. D.; Pryor, L. L.

    1978-01-01

    The nature and improvement in satellite orbit determination when precise altimetric height data are used in combination with conventional tracking data was determined. A digital orbit determination program was developed that could singly or jointly use laser ranging, C-band ranging, Doppler range difference, and altimetric height data. Two intervals were selected and used in a preliminary evaluation of the altimeter data. With the data available, it was possible to determine the semimajor axis and eccentricity to within several kilometers, in addition to determining an altimeter height bias. When used jointly with a limited amount of either C-band or laser range data, it was shown that altimeter data can improve the orbit solution.

  9. Geostationary Satellite (GOES) Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visible and Infrared satellite imagery taken from radiometer instruments on SMS (ATS) and GOES satellites in geostationary orbit. These satellites produced...

  10. Neptune's small satellites

    Science.gov (United States)

    Thomas, P.

    1992-04-01

    The small satellites of Neptune and other planets discovered during the Voyager 2 mission are discussed in terms of their composition and relationship to the planetary systems. The satellite Proteus is described in terms of its orbit, five other satellites are described, and they are compared to ther small satellites and systems. Neptune's satellites are hypothesized to be related to the ring system, and the satellite Galatea is related to the confinement of the rings.

  11. Molecular authentication of geo-authentic Scrophularia ningpoensis

    Institute of Scientific and Technical Information of China (English)

    Chuan CHEN; Li-na DUAN; Xiao-long ZHOU; Bing-long CHEN; Cheng-xin FU

    2011-01-01

    Scrophularia ningpoensis has long been used in the Chinese Materia Medica for inflammation. Like other herbal medicines, S. ningpoensis collected from different localities may considerably differ in their therapeutic efficacy,and the one grown in Zhejiang Province is recognized as geo-authentic. However, it is difficult to confirm the geographical authenticity by similar morphological characteristics. In the present study, inter-simple sequence repeat (ISSR) markers were conducted to detect S. ningpoensis from different origins. A 1259-bp fragment amplified by primer UBC874 was found only in geo-authentic ones. By cloning and sequencing that specific band, sequence characterized amplified region (SCAR) markers were designed to distinguish geo-authentic S. ningpoensis from others.This is a rapid and easy method that can be used to identify the geographical authenticity of S. ningpoensis.

  12. FindGeo: a tool for determining metal coordination geometry.

    Science.gov (United States)

    Andreini, Claudia; Cavallaro, Gabriele; Lorenzini, Serena

    2012-06-15

    Metals are essential for the structure and function of many proteins and nucleic acids. The geometrical arrangement of the atoms that coordinate a metal in a biological macromolecule is an important determinant of the specificity and role of that metal. At present, however, this information can be retrieved only from the literature, which sometimes contains an improper or incorrect description of the geometry, and often lacks it altogether. Thus, we developed FindGeo to quickly and easily determine the coordination geometry of selected, or all, metals in a given structure. FindGeo works by superimposing the metal-coordinating atoms in the input structure to a library of templates with alternative ideal geometries, which are ranked by RMSD to identify the best geometry assignment. FindGeo is freely available as a web service and as a stand-alone program at http://metalweb.cerm.unifi.it/tools/findgeo/.

  13. Geo-communication and web-based infrastructure

    DEFF Research Database (Denmark)

    Brodersen, Lars; Nielsen, Anders

    2005-01-01

    in the infrastructure. The figure below illustrates the passive elements of geo-communication (plus a user), i.e. geo-information and infrastructure. All processes shown in the illustration can be iterative. The illustration can be seen as a longitudinal section of the overall process. The paper discusses...... the illustration below as well as the accompanying cross-section illustration and the impact thereof. Discussed is also a model for the organization of the passive components of the infrastructure; i.e. legislation, collaboration, standards, models, specifications, web-services and finally the information...... number of all kinds of information and combinations of these) characterize web-services, where maps are only a part of the whole. These new conditions demand new ways of modelling the processes leading to geo-communication. One new aspect is the fact that the service providers have become a part...

  14. From Order to Chaos in Earth Satellite Orbits

    Science.gov (United States)

    Gkolias, Ioannis; Daquin, Jérôme; Gachet, Fabien; Rosengren, Aaron J.

    2016-11-01

    We consider Earth satellite orbits in the range of semimajor axes where the perturbing effects of Earth’s oblateness and lunisolar gravity are of comparable order. This range covers the medium-Earth orbits (MEO) of the Global Navigation Satellite Systems and the geosynchronous orbits (GEO) of the communication satellites. We recall a secular and quadrupolar model, based on the Milankovitch vector formulation of perturbation theory, which governs the long-term orbital evolution subject to the predominant gravitational interactions. We study the global dynamics of this two-and-a-half degrees-of-freedom Hamiltonian system by means of the fast Lyapunov indicator (FLI), used in a statistical sense. Specifically, we characterize the degree of chaoticity of the action space using angle-averaged normalized FLI maps, thereby overcoming the angle dependencies of the conventional stability maps. Emphasis is placed upon the phase-space structures near secular resonances, which are of primary importance to the space debris community. We confirm and quantify the transition from order to chaos in MEO, stemming from the critical inclinations and find that highly inclined GEO orbits are particularly unstable. Despite their reputed normality, Earth satellite orbits can possess an extraordinarily rich spectrum of dynamical behaviors and, from a mathematical perspective, have all the complications that make them very interesting candidates for testing the modern tools of chaos theory.

  15. GeoCEGAS: natural gas distribution management system

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Lorena C.J. [Companhia de Gas do Ceara (CEGAS), Fortaleza, CE (Brazil); Targa, Fernando O. [Gestao Empresarial e Informatica Ltda. (GEMPI), Sao Paulo, SP (Brazil)

    2009-07-01

    This Technical Paper approach the conception, architecture, design, construction, and implementation of GeoCEGAS, a spatially enabled corporate management information system, oriented to store and provide Web access, to information associated with the natural gas distribution network, owned by CEGAS. This paper reports business processes, business entities and business intelligence approached on the project, as well as an overview of system architecture, applications, and technology used on the implementation of GeoCEGAS. Finally, is presented an introduction to the work methodology used, as well a synopsis of benefits achievements. (author)

  16. A NOVEL INDOOR GEO-LOCATION METHOD USING MIMO ARRAY

    Institute of Scientific and Technical Information of China (English)

    Sun Guolin; Guo Wei

    2006-01-01

    In a Multiple-Input Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) based Wireless Local Area Network (WLAN) system, both Access Points (Aps) and Mobile Terminals (MTs) are configured with multiple antennas, to make novel indoor geo-location method possible. In this paper, we presented a novel Least Square Support Vector Machine (LS-SVM) based data fusion algorithm to fuse signal strength measurements for indoor geo-location using only a single AP with MIMO arrays. We evaluate our proposed algorithms under indoor environments by MATLAB simulations. Simulation results show that our MIMO-based algorithm is superior to conventional least square algorithm.

  17. 3D Geo-Information in Urban Climate Studies

    Science.gov (United States)

    Petrescu, F.; Aldea, M.; Luca, O.; Iacoboaea, C.; Gaman, F.; Parlow, E.

    2016-10-01

    3D geo-information is essential for urban climate studies. It is obvious that both natural environment and built-up environment play the fundamental role in defining the climatic conditions for urban areas, which affect the quality of human life and human comfort. The paper presents the main categories of 3D geo-information used in urban climate studies and roles in creating and operating the numerical models specially designed to simulate urban planning scenarios and improvement of the urban climate situation.

  18. GeoGebra Tool for Building Conceptual Understanding in Mathematics

    Directory of Open Access Journals (Sweden)

    Daniela Velichová

    2010-05-01

    Full Text Available At the beginning of the 3rd millennium we are facing dramatic changes in the basic nature of teaching and learning strategies caused by massive use of new ICT. We can benefit from this development in general, and in mathematics especially, as currently available dynamic and visual learning environments as software GeoGebra could affect our perspective in terms of the content and comprehension of mathematics education. Few ideas are presented on how GeoGebra can be used as tool for creating cognitive connections between different representations of mathematical concepts, which form the necessary background for better conceptual understanding, steady knowledge and mathematical literacy.

  19. Communications satellite business ventures - Measuring the impact of technology programmes and related policies

    Science.gov (United States)

    Greenberg, J. S.

    1986-01-01

    An economic evaluation and planning procedure which assesses the effects of various policies on fixed satellite business ventures is described. The procedure is based on a stochastic financial simulation model, the Domsat II, which evaluates spacecraft reliability, market performance, and cost uncertainties. The application of the Domsat II model to the assessment of NASA's ion thrusters for on-orbit propulsion and GaAs solar cell technology is discussed. The effects of insurance rates and the self-insurance option on the financial performance of communication satellite business ventures are investigated. The selection of a transportation system for placing the satellites into GEO is analyzed.

  20. Communications satellite business ventures - Measuring the impact of technology programmes and related policies

    Science.gov (United States)

    Greenberg, J. S.

    1986-01-01

    An economic evaluation and planning procedure which assesses the effects of various policies on fixed satellite business ventures is described. The procedure is based on a stochastic financial simulation model, the Domsat II, which evaluates spacecraft reliability, market performance, and cost uncertainties. The application of the Domsat II model to the assessment of NASA's ion thrusters for on-orbit propulsion and GaAs solar cell technology is discussed. The effects of insurance rates and the self-insurance option on the financial performance of communication satellite business ventures are investigated. The selection of a transportation system for placing the satellites into GEO is analyzed.

  1. Determination of the position of the station Borowiec Nr 7811 by satellite laser observations

    Science.gov (United States)

    Dobaczewska, W.; Drozyner, A.; Rutkowska, M.; Schillak, S.; Zielinski, J. B.

    Laser observations during 1977-1979 of the GEOS-1 and GEOS-3 satellites, used to determine the geocentric position of the Astronomical Latitude Observatory in Borowiec (station No. 7811) are examined. The data are processed by means of the ORBITA program and the GRIPE program elaborated at the Smithsonian Astrophysical Observatory. The coordinates of the station are calculated by a dynamical orbital method. Results of the ORBITA and GRIPE solutions are presented in tables. A comparison of these two solutions with the Wettzel-Borowiec translocation solution is considered.

  2. Numerical arc segmentation algorithm for a radio conference - A software tool for communication satellite systems planning

    Science.gov (United States)

    Whyte, W. A.; Heyward, A. O.; Ponchak, D. S.; Spence, R. L.; Zuzek, J. E.

    1988-01-01

    A detailed description of a Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC) software package for communication satellite systems planning is presented. This software provides a method of generating predetermined arc segments for use in the development of an allotment planning procedure to be carried out at the 1988 World Administrative Radio Conference (WARC - 88) on the use of the GEO and the planning of space services utilizing GEO. The features of the NASARC software package are described, and detailed information is given about the function of each of the four NASARC program modules. The results of a sample world scenario are presented and discussed.

  3. Comparison of BRDF-Predicted and Observed Light Curves of GEO Satellites

    Science.gov (United States)

    2015-10-18

    as the sum of the specular and diffuse reflections, which are functions of its material properties, as well as the angles of incidence and...illumination model. The Ashikhmin-Premoze BRDF differs from the Ashikhmin-Shirley model mainly in that it simplifies the denominator of the specular term...models incorporate diffuse and specular reflectivity terms. While the specular term consists of the light reflected in a specific direction, as

  4. A Geos 3 Orbit determination experiment

    Science.gov (United States)

    Pisacane, V. L.; Eisner, A.; Yionoulis, S. M.; Mcconahy, R. J.; Black, H. D.; Pryor, L. L.

    1979-01-01

    The purpose of this experiment was to investigate the value of altimetry data in high-precision satellite orbit determination. To accomplish this, software was developed to process laser, C-band, doppler and altimeter data singly or jointly. Initially, orbit determination studies were undertaken using synthetic data to validate the software. As data became available, preliminary experiments were carried out. When all the data became available, an intensive study was made covering a 4-day span in 1976. The results showed that even with sparse altimeter data it was possible to accurately determine the semimajor axis and eccentricity with altimeter data only. When altimeter data was supplemented with (as few as) two C-band passes, high-precision ephemerides were obtained. Using two laser passes to supplement the altimetry data did not achieve that same high precision. This is probably because the geographic location (mid-Atlantic) of the highly accurate laser data were such that they did not ideally complement the available (south Atlantic and Indian Ocean) altimeter data.

  5. The CCOP-IUGS/GEM Thematic Session on "Sustainable development of geo-resources & geo-environment"

    Institute of Scientific and Technical Information of China (English)

    Colin Simpson

    2006-01-01

    @@ The Coordinating Committee for Geoscience Programmes in East and Southeast Asia (CCOP) is an intergovernmental organization whose mission is to facilitate and coordinate the implementation of applied geoscience programmes in East and Southeast Asia in order to contribute to economic development and the improvement of the quality of life in the region. To this end,CCOP promotes capacity building, technology transfer, exchange of information and institutional linkages for sustainable resource development, management of geo-information, geo-hazard mitigation and protection of the environment (http://www.ccop.or.th/sitemap.asp).

  6. Concept of a spatial data infrastructure for web-mapping, processing and service provision for geo-hazards

    Science.gov (United States)

    Weinke, Elisabeth; Hölbling, Daniel; Albrecht, Florian; Friedl, Barbara

    2017-04-01

    Geo-hazards and their effects are distributed geographically over wide regions. The effective mapping and monitoring is essential for hazard assessment and mitigation. It is often best achieved using satellite imagery and new object-based image analysis approaches to identify and delineate geo-hazard objects (landslides, floods, forest fires, storm damages, etc.). At the moment, several local/national databases and platforms provide and publish data of different types of geo-hazards as well as web-based risk maps and decision support systems. Also, the European commission implemented the Copernicus Emergency Management Service (EMS) in 2015 that publishes information about natural and man-made disasters and risks. Currently, no platform for landslides or geo-hazards as such exists that enables the integration of the user in the mapping and monitoring process. In this study we introduce the concept of a spatial data infrastructure for object delineation, web-processing and service provision of landslide information with the focus on user interaction in all processes. A first prototype for the processing and mapping of landslides in Austria and Italy has been developed within the project Land@Slide, funded by the Austrian Research Promotion Agency FFG in the Austrian Space Applications Program ASAP. The spatial data infrastructure and its services for the mapping, processing and analysis of landslides can be extended to other regions and to all types of geo-hazards for analysis and delineation based on Earth Observation (EO) data. The architecture of the first prototypical spatial data infrastructure includes four main areas of technical components. The data tier consists of a file storage system and the spatial data catalogue for the management of EO-data, other geospatial data on geo-hazards, as well as descriptions and protocols for the data processing and analysis. An interface to extend the data integration from external sources (e.g. Sentinel-2 data) is planned

  7. From order to chaos in Earth satellite orbits

    CERN Document Server

    Gkolias, Ioannis; Gachet, Fabien; Rosengren, Aaron J

    2016-01-01

    We consider Earth satellite orbits in the range of semi-major axes where the perturbing effects of Earth's oblateness and lunisolar gravity are of comparable order. This range covers the medium-Earth orbits (MEO) of the Global Navigation Satellite Systems and the geosynchronous orbits (GEO) of the communication satellites. We recall a secular and quadrupolar model, based on the Milankovitch vector formulation of perturbation theory, which governs the long-term orbital evolution subject to the predominant gravitational interactions. We study the global dynamics of this two-and-a-half degrees of freedom Hamiltonian system by means of the fast Lyapunov indicator (FLI), used in a statistical sense. Specifically, we characterize the degree of chaoticity of the action space using angles-averaged normalized FLI maps, thereby overcoming the angle dependencies of the conventional stability maps. Emphasis is placed upon the phase-space structures near secular resonances which are of first importance to the space debris...

  8. Laser Communication Experiments with Artemis Satellite

    Science.gov (United States)

    Kuzkov, Sergii; Sodnik, Zoran; Kuzkov, Volodymyr

    2013-10-01

    In November 2001, the European Space Agency (ESA) established the world-first inter-satellite laser communication link between the geostationary ARTEMIS satellite and the low Earth orbiting (LEO) SPOT-4 Earth observation satellite, demonstrating data rates of 50 Mbps. In 2006, the Japanese Space Agency launched the KIRARI (OICETS) LEO satellite with a compatible laser communication terminal and bidirectional laser communication links (50 Mbps and 2 Mbps) were successfully realized between KIRARI and ARTEMIS. ESA is now developing the European Data Relay Satellite (EDRS) system, which will use laser communication technology to transmit data between the Sentinel 1 and 2 satellites in LEO to two geostationary satellites (EDRS-A and EDRS-C) at data rates of 1.8 Gbps. As the data handling capabilities of state-of-the-art telecommunication satellites in GEO increase so is the demand for the feeder-link bandwidth to be transmitted from ground. This is why there is an increasing interest in developing high bandwidth ground-to-space laser communication systems working through atmosphere. In 2002, the Main Astronomical Observatory (MAO) started the development of its own laser communication system for its 0.7m AZT-2 telescope, located in Kyiv, Ukraine. The work was supported by the National Space Agency of Ukraine and by ESA. MAO developed a highly accurate computerized tracking system for AZT-2 telescope and a compact laser communication package called LACES (Laser Atmosphere and Communication Experiments with Satellites). The LACES instrument includes a camera of the pointing and tracking subsystems, a receiver module, a laser transmitter module, a tip/tilt atmospheric turbulence compensation subsystem, a bit error rate tester module and other optical and electronic components. The principal subsystems are mounted on a platform, which is located at the Cassegrain focus of the AZT-2 telescope. All systems were tested with the laser communication payload on-board ARTEMIS and

  9. Economic Development and Forest Cover: Evidence from Satellite Data

    Science.gov (United States)

    Crespo Cuaresma, Jesús; Danylo, Olha; Fritz, Steffen; McCallum, Ian; Obersteiner, Michael; See, Linda; Walsh, Brian

    2017-01-01

    Ongoing deforestation is a pressing, global environmental issue with direct impacts on climate change, carbon emissions, and biodiversity. There is an intuitive link between economic development and overexploitation of natural resources including forests, but this relationship has proven difficult to establish empirically due to both inadequate data and convoluting geo-climactic factors. In this analysis, we use satellite data on forest cover along national borders in order to study the determinants of deforestation differences across countries. Controlling for trans-border geo-climactic differences, we find that income per capita is the most robust determinant of differences in cross-border forest cover. We show that the marginal effect of per capita income growth on forest cover is strongest at the earliest stages of economic development, and weakens in more advanced economies, presenting some of the strongest evidence to date for the existence of at least half of an environmental Kuznets curve for deforestation.

  10. Fukushima : The Geo-Trauma of a Futural Wave

    NARCIS (Netherlands)

    Dolphijn, R.; Cole, David; Bradley, Joff

    2016-01-01

    The enduring effects of the March 2011 tsunami and nuclear meltdown at the Fukushima Dai-ichi Nuclear Power Station in Japan are explored in this paper through the notions of “geo-trauma” in the authors’ work and geophilosophy in Deleuze and Guattari’s philosophy. At the fulcrum of the 2011 global d

  11. Students' Performance in Geometrical Reflection Using GeoGebra

    Science.gov (United States)

    Seloraji, Pavethira; Eu, Leong Kwan

    2017-01-01

    Students in this era need to grasp the concept of geometry instead of memorizing formulae. This is important for them to further their knowledge in geometry. The purpose of the research was to determine whether GeoGebra software influences year one students' performance in geometrical reflection. The research utilized an experimental research…

  12. Value Assessment in Managing Cartography and Geo-communication

    DEFF Research Database (Denmark)

    Brodersen, Lars

    2006-01-01

    and the management in modern cartography and in modern geo-spatial communication projects. It was recognized that there was a lack of adequate theories, models, methods and tech-niques. This forced the cartographers and the project managers to lock several parameters to well known values. One example...

  13. Design of GEO helix tourist orbit based on perturbation compensation

    Science.gov (United States)

    Xu, Yanli; Zhou, Haijun; Dai, Huayu

    2017-05-01

    Constrained by country area and technology level, GEO target and environment's detection become practical difficulty which restrict development of our country's space technology. Helix tourist orbit is introduced; orbit formation effect from perturbation of nonsphericfigure of the Earth, the solar and lunar attraction is analyzed; orbit design method based on perturbation compensation is put forward.

  14. A novel insight into beaconless geo-routing

    KAUST Repository

    Bader, Ahmed

    2012-12-01

    Beaconless geo-routing protocols have been traditionally analyzed assuming equal communication ranges for the data and control packets. This is not true in reality, since the communication range is in practice function of the packet length. As a consequence, a substantial discrepancy may exist between analytical and empirical results offered in beaconless geo-routing literature. Furthermore, performance of beaconless geo-routing protocols has typically considered using single-hop metrics only. End-to-end performance is considered in literature only occasionally and mainly in terms of simulation only. In this paper, we re-examine this class of protocols. We first incorporate practical packet detection models in order to capture the dependency of the communication range on the packet\\'s length. We then develop a detailed analytical framework for the end-to-end delay and energy performance of beaconless geo-routing protocols. Finally, we present two different application scenarios and study various tradeoffs in light of the framework developed. © 2012 IEEE.

  15. Big Data analytics in the Geo-Spatial Domain

    NARCIS (Netherlands)

    Goncalves, R.A.; Ivanova, M.G.; Kersten, M.L.; Scholten, H.; Zlatanova, S.; Alvanaki, F.; Nourian, P.; Dias, E.

    2014-01-01

    Big data collections in many scientific domains have inherently rich spatial and geo-spatial features. Spatial location is among the core aspects of data in Earth observation sciences, astronomy, and seismology to name a few. The goal of our project is to design an efficient data management layer fo

  16. Improving geo-information reliability by centralized change detection management

    NARCIS (Netherlands)

    Gorte, B.; Nardinocchi, C.; Thonon, I.; Addink, E.; Beck, R.; Persie, van M.; Kramer, H.

    2006-01-01

    A consortium called Mutatis Mutandis (MutMut), consisting of three Universities and eight producers and users of geo-information, was established in the Netherlands to streamline change detection on a national level. After preliminary investigations concerning market feasibility, three actions are

  17. Fukushima : The Geo-Trauma of a Futural Wave

    NARCIS (Netherlands)

    Dolphijn, R.; Cole, David; Bradley, Joff

    2016-01-01

    The enduring effects of the March 2011 tsunami and nuclear meltdown at the Fukushima Dai-ichi Nuclear Power Station in Japan are explored in this paper through the notions of “geo-trauma” in the authors’ work and geophilosophy in Deleuze and Guattari’s philosophy. At the fulcrum of the 2011 global

  18. Paradigm shift from cartography to geo-communication

    DEFF Research Database (Denmark)

    Brodersen, Lars

    2007-01-01

    This paper argues that the domain of GIS, cartography, geo-information etc. is facing a paradigm shift. The implication of a paradigm shift is a complete and necessary re-definition of e.g. the philosophical foundation of the system, as well as with a major upgrade and readjustment of procedures...

  19. Regional Files of GEOS3/SEASAT/GEOSAT Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gravity anomalies and sea surface heights have been computed on a 0.125 degree grid in the ocean areas from a combined GEOS3/SEASAT/GEOSAT altimeter data set. This...

  20. [Fernand Braudel and the geo-history of civilizations].

    Science.gov (United States)

    Ribeiro, Guilherme

    2011-03-01

    The article discusses the valuable role of geography in the study of civilizations entitled Grammaire des civilisations (A history of civilizations), by French historian Fernand Braudel. It also focuses on the epistemological role of the concept of geo-history in Braudel's thought. The article's underlying assumption is that geography has been crucial to comprehending history over large spans of time.

  1. Improved Vote Aggregation Techniques for the Geo-Wiki Cropland Capture Crowdsourcing Game

    Science.gov (United States)

    Baklanov, Artem; Fritz, Steffen; Khachay, Michael; Nurmukhametov, Oleg; Salk, Carl; See, Linda; Shchepashchenko, Dmitry

    2016-04-01

    Crowdsourcing is a new approach for solving data processing problems for which conventional methods appear to be inaccurate, expensive, or time-consuming. Nowadays, the development of new crowdsourcing techniques is mostly motivated by so called Big Data problems, including problems of assessment and clustering for large datasets obtained in aerospace imaging, remote sensing, and even in social network analysis. By involving volunteers from all over the world, the Geo-Wiki project tackles problems of environmental monitoring with applications to flood resilience, biomass data analysis and classification of land cover. For example, the Cropland Capture Game, which is a gamified version of Geo-Wiki, was developed to aid in the mapping of cultivated land, and was used to gather 4.5 million image classifications from the Earth's surface. More recently, the Picture Pile game, which is a more generalized version of Cropland Capture, aims to identify tree loss over time from pairs of very high resolution satellite images. Despite recent progress in image analysis, the solution to these problems is hard to automate since human experts still outperform the majority of machine learning algorithms and artificial systems in this field on certain image recognition tasks. The replacement of rare and expensive experts by a team of distributed volunteers seems to be promising, but this approach leads to challenging questions such as: how can individual opinions be aggregated optimally, how can confidence bounds be obtained, and how can the unreliability of volunteers be dealt with? In this paper, on the basis of several known machine learning techniques, we propose a technical approach to improve the overall performance of the majority voting decision rule used in the Cropland Capture Game. The proposed approach increases the estimated consistency with expert opinion from 77% to 86%.

  2. GeoBus: sharing science research with schools

    Science.gov (United States)

    Roper, Kathryn; Robinson, Ruth; Moorhouse, Ben

    2016-04-01

    GeoBus (www.geobus.org.uk) is an educational outreach project that was developed in 2012 by the Department of Earth and Environmental Sciences at the University of St Andrews, and it is currently sponsored by industry, NERC, The Crown Estate, and the Scottish Government. The aims of GeoBus are to support the teaching of Earth Science in secondary (middle and high) schools by providing teaching support to schools that have little or no experience in teaching this subject. This is, in part, done through the sharing of new science research outcomes and the experiences of young researchers with school pupils to provide a bridge between industry, higher education institutions, research councils and schools. Since its launch, over 40,000 pupils will have been involved in experiential Earth science learning activities in 190 different schools (over 400 separate visits) across the length and breadth of Scotland: many of these schools are in remote and disadvantaged regions. A new GeoBus project is under development within the Department of Earth Sciences at UCL in London. A key aim of GeoBus is to incorporate new research into our workshops with the main challenge being the development of appropriate resources that incorporate the key learning aims and requirements of the science and geography curricula. GeoBus works closely with researchers, teachers and educational practitioners to tailor the research outcomes to the curricula as much as possible. Over the past four years, GeoBus has developed 17 workshops, 5 challenge events and extensive field trips and each of these activities are trialled and evaluated within the university, and adjustments are made before the activities are delivered in schools. Activities are continually reviewed and further developments are made in response to both teacher and pupil feedback. This critical reflection of the project's success and impact is important to insure a positive and significant contribution to the science learning in

  3. Activities for Plate Tectonics using GeoMapApp

    Science.gov (United States)

    Goodwillie, A. M.

    2016-12-01

    The concept of plate tectonics is a fundamental component of our understanding of how Earth works yet authentic, high-quality geoscience data related to plate tectonics may not be readily available to all students. To compound matters, when data is accessible, students may not possess the skills or resources necessary to explore and analyse it. As a result, much emphasis at federal and state level is now placed upon encouraging students to work with more data and more technology more often and more rigourously. Easy-to-use digital platforms offer much potential for promoting inquiry-based learning at all levels of education. GeoMapApp is one such tool. Developed at Columbia University's Lamont-Doherty Earth Observatory, GeoMapApp (http://www.geomapapp.org) is a free resource that integrates a wide range of research-grade geoscience data in one intuitive map-based interface. Simple strategies for data manipulation, visualisation and presentation allow uses to explore the data in meaningful ways. Layering and transparency capabilities further allow learners to use GeoMapApp to compare multiple data sets at once, and high-impact Save Session functionality allows a GeoMapApp project to be saved for sharing or later use. In this presentation, activities related to plate tectonics will be highlighted. One GeoMapApp activity helps students investigate plate boundaries by exploring earthquake and volcano locations. Another requires students to calculate the rate of seafloor spreading using crustal age data in various ocean basins. A third uses the GeoMapApp layering technique to explore the influence of geological forces in shaping the landscape. Each activity shown can be done by students on an individual basis, as pairs, or as groups. Educators report that student use of GeoMapApp fosters an increased sense of data "ownership" amongst students, promotes STEM skills, and provides them with access to authentic research-grade geoscience data using the same cutting

  4. Web catalog of oceanographic data using GeoNetwork

    Science.gov (United States)

    Marinova, Veselka; Stefanov, Asen

    2017-04-01

    Most of the data collected, analyzed and used by Bulgarian oceanographic data center (BgODC) from scientific cruises, argo floats, ferry boxes and real time operating systems are spatially oriented and need to be displayed on the map. The challenge is to make spatial information more accessible to users, decision makers and scientists. In order to meet this challenge, BgODC concentrate its efforts on improving dynamic and standardized access to their geospatial data as well as those from various related organizations and institutions. BgODC currently is implementing a project to create a geospatial portal for distributing metadata and search, exchange and harvesting spatial data. There are many open source software solutions able to create such spatial data infrastructure (SDI). Finally, the GeoNetwork open source is chosen, as it is already widespread. This software is free, effective and "cheap" solution for implementing SDI at organization level. It is platform independent and runs under many operating systems. Filling of the catalog goes through these practical steps: • Managing and storing data reliably within MS SQL spatial data base; • Registration of maps and data of various formats and sources in GeoServer (most popular open source geospatial server embedded with GeoNetwork) ; • Filling added meta data and publishing geospatial data at the desktop of GeoNetwork. GeoServer and GeoNetwork are based on Java so they require installing of a servlet engine like Tomcat. The experience gained from the use of GeoNetwork Open Source confirms that the catalog meets the requirements for data management and is flexible enough to customize. Building the catalog facilitates sustainable data exchange between end users. The catalog is a big step towards implementation of the INSPIRE directive due to availability of many features necessary for producing "INSPIRE compliant" metadata records. The catalog now contains all available GIS data provided by BgODC for Internet

  5. Feasibility Analysis on the Utilization of the Iridium Satellite Communications Network for Resident Space Objects in Low Earth Orbit

    Science.gov (United States)

    2013-03-21

    equatorial speed. Ideally, the GEO satellite remains directly overhead in the absence of perturbing forces. Of course , perturbing forces exist and cause a...respectively. Assuming a mean Earth radius of 6371 km, the Earth- central angles and can be found from trigonometry using the footprint

  6. The GEO Geohazard Supersites and Natural Laboratories - GSNL 2.0: improving societal benefits of Geohazard science

    Science.gov (United States)

    Salvi, Stefano

    2016-04-01

    The Geohazard Supersites and Natural Laboratories initiative began with the "Frascati declaration" at the conclusion of the 3rd International Geohazards workshop of GEO held in November 2007 in Frascati, Italy. The recommendation of the workshop was "to stimulate an international and intergovernmental effort to monitor and study selected reference sites by establishing open access to relevant datasets according to GEO principles, to foster the collaboration between all various partners and end-users". This recommendation was later formalized in the GEO Work Plan as Component 2 of the GEO task DI-01, part of the GEO Disasters Societal Benefit Area. Today GSNL has grown to a voluntary collaboration among monitoring agencies, scientific community and the CEOS space agencies, working to improve the scientific understanding of earthquake and volcanic phenomena and enable better risk assessment and emergency management. According to its principles, actions in GSNL are focused on specific areas of the world, the Supersites, for which large amounts of in situ and satellite data are made openly available to all scientists. These areas are selected based on the importance of the scientific problems, as well as on the amount of population at risk, and should be evenly distributed among developed and less developed countries. Seven Supersites have been established to date, six of which on volcanic areas (Hawaii, US; Icelandic volcanoes; Mt. Etna, IT; Campi Flegrei, IT; Ecuadorian volcanoes, Taupo, NZ), and one on a seismic area (Western North Anatolian fault, TR). One more proposals is being evaluated: the Corinth Gulf in Greece. The Supersites have succeeded in promoting new scientific developments by providing a framework for an easier access to EO and in situ data. Coordination among researchers at the global scale has been achieved only where the Supersite activities were sustained through well established projects. For some Supersites a close coordination between

  7. Access to geo information in Europe: Is the marine sector showing the way?

    NARCIS (Netherlands)

    Welle Donker, F.M.; De Jong, J.

    2010-01-01

    In the digital age, geo-information or spatial data has become embedded in our daily lives. Although the term geo-information does not ring familiar, applications such as navigation systems, real estate information and weather forecasts are used by all for day-to-day decision-making. Most geo-inform

  8. Semantic annotation of existing geo-datasets: A case study of disaster response in Netherlands

    NARCIS (Netherlands)

    Mobasheri, A.; Van Oosterom, P.J.M.; Zlatanova, S.; Bakillah, M.

    2013-01-01

    Use of relevant geo-information is one of the important issues for performing different tasks and processes in disaster response phase. In order to save time and cost, services could be employed for integrating and extracting relevant up-to-date geo-information. For this purpose, semantics of geo-in

  9. Research on geo-ontology construction based on spatial affairs

    Science.gov (United States)

    Li, Bin; Liu, Jiping; Shi, Lihong

    2008-12-01

    Geo-ontology, a kind of domain ontology, is used to make the knowledge, information and data of concerned geographical science in the abstract to form a series of single object or entity with common cognition. These single object or entity can compose a specific system in some certain way and can be disposed on conception and given specific definition at the same time. Ultimately, these above-mentioned worked results can be expressed in some manners of formalization. The main aim of constructing geo-ontology is to get the knowledge of the domain of geography, and provide the commonly approbatory vocabularies in the domain, as well as give the definite definition about these geographical vocabularies and mutual relations between them in the mode of formalization at different hiberarchy. Consequently, the modeling tool of conception model of describing geographic Information System at the hiberarchy of semantic meaning and knowledge can be provided to solve the semantic conception of information exchange in geographical space and make them possess the comparatively possible characters of accuracy, maturity and universality, etc. In fact, some experiments have been made to validate geo-ontology. During the course of studying, Geo-ontology oriented to flood can be described and constructed by making the method based on geo-spatial affairs to serve the governmental departments at all levels to deal with flood. Thereinto, intelligent retrieve and service based on geoontology of disaster are main functions known from the traditional manner by using keywords. For instance, the function of dealing with disaster information based on geo-ontology can be provided when a supposed flood happened in a certain city. The correlative officers can input some words, such as "city name, flood", which have been realized semantic label, to get the information they needed when they browse different websites. The information, including basic geographical information and flood distributing

  10. Satellite data compression

    CERN Document Server

    Huang, Bormin

    2011-01-01

    Satellite Data Compression covers recent progress in compression techniques for multispectral, hyperspectral and ultra spectral data. A survey of recent advances in the fields of satellite communications, remote sensing and geographical information systems is included. Satellite Data Compression, contributed by leaders in this field, is the first book available on satellite data compression. It covers onboard compression methodology and hardware developments in several space agencies. Case studies are presented on recent advances in satellite data compression techniques via various prediction-

  11. Trends in communications satellites

    CERN Document Server

    Curtin, Denis J

    1979-01-01

    Trends in Communications Satellites offers a comprehensive look at trends and advances in satellite communications, including experimental ones such as NASA satellites and those jointly developed by France and Germany. The economic aspects of communications satellites are also examined. This book consists of 16 chapters and begins with a discussion on the fundamentals of electrical communications and their application to space communications, including spacecraft, earth stations, and orbit and wavelength utilization. The next section demonstrates how successful commercial satellite communicati

  12. GEO Standard and Interoperability Forum (SIF) European Team

    Science.gov (United States)

    Nativi, Stefano

    2010-05-01

    The European GEO SIF has been initiated by the GIGAS project in an effort to better coordinate European requirements for GEO and GEOSS related activities, and is recognised by GEO as a regional SIF. To help advance the interoperability goals of the Global Earth Observing System of Systems (GEOSS), the Group on Earth Observations (GEO) Architecture and Data Committee (ADC) has established a Standards and Interoperability Forum (SIF) to support GEO organizations offering components and services to GEOSS. The SIF will help GEOSS contributors understand how to work with the GEOSS interoperability guidelines and how to enter their "interoperability arrangements" (standards or other ad hoc arrangements for interoperability) into the GEOSS registries. This will greatly facilitate the utility of GEOSS and encourage significant increase in participation. To carry out its work most effectively, the SIF promotes to form Regional Teams. They will help to organize and optimize the support coming from the different parts of the World and reach out regional and multi-disciplinary Scientific Communities. This will allow to have true global representation in supporting GEOSS interoperability. A SIF European Team is foreseen. The main role of the SIF is facilitating interoperability and working with members and participating organizations as they offer data and information services to the users of GEOSS. In this framework, the purpose of having a European Regional Team is to increase efficiency in carrying out the work of the SIF. Experts can join the SIF European Team by registering at the SIF European Team wiki site: http://www.thegigasforum.eu/sif/

  13. BeiDou Inter-Satellite-Type Bias Evaluation and Calibration for Mixed Receiver Attitude Determination

    Directory of Open Access Journals (Sweden)

    Noor Raziq

    2013-07-01

    Full Text Available The Chinese BeiDou system (BDS, having different types of satellites, is an important addition to the ever growing system of Global Navigation Satellite Systems (GNSS. It consists of Geostationary Earth Orbit (GEO satellites, Inclined Geosynchronous Satellite Orbit (IGSO satellites and Medium Earth Orbit (MEO satellites. This paper investigates the receiver-dependent bias between these satellite types, for which we coined the name “inter-satellite-type bias” (ISTB, and its impact on mixed receiver attitude determination. Assuming different receiver types may have different delays/biases for different satellite types, we model the differential ISTBs among three BeiDou satellite types and investigate their existence and their impact on mixed receiver attitude determination. Our analyses using the real data sets from Curtin’s GNSS array consisting of different types of BeiDou enabled receivers and series of zero-baseline experiments with BeiDou-enabled receivers reveal the existence of non-zero ISTBs between different BeiDou satellite types. We then analyse the impact of these biases on BeiDou-only attitude determination using the constrained (C-LAMBDA method, which exploits the knowledge of baseline length. Results demonstrate that these biases could seriously affect the integer ambiguity resolution for attitude determination using mixed receiver types and that a priori correction of these biases will dramatically improve the success rate.

  14. An analysis of the wide area differential method of geostationary orbit satellites

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This work aims to obtain a wide area differential method for geostationary orbit (GEO) constellation. A comparison between the dilution of precision (DOP) of four-dimensional (4D) calculation including sa- tellite clock errors and ephemeris errors and that of three-dimensional (3D) calculation only including ephemeris errors with the inverse positioning theory of GPS shows the conclusion that all the 3D PDOPs are greatly reduced. Based on this, a basic idea of correcting satellite clock errors and ephem- eris errors apart is put forward, and moreover, a specific method of separation is proposed. Satellite clock errors are separated in a master station with time synchronization, and all the remaining pseu- do-range errors after the satellite clock errors have been deducted are used to work out ephemeris corrections of all GEO satellites. By a comparative analysis of user positioning accuracy before and after differential, the wide area differential method is verified to be quite valid for GEO constellation.

  15. A world freshwater assessment using Landsat multispectral data from GeoCover

    Science.gov (United States)

    Verpoorter, C.; Kutser, T.,; Tranvik, L.,

    2012-04-01

    Oceanic observation networks are being increasingly developed around the world, for instance by integrating advance remote sensing techniques and monitoring measurements. However, freshwater systems have received less attention. Surprisingly, although recent studies demonstrated that inland waters play a significant role in the carbon cycle, estimation of carbon stocks and fluxes may often be biased mainly because inventories and archives are incomplete, or hard to access. In particular, the total number and total area of lakes remain highly uncertain, particularly for the small lake size category. Usually, indirect probability-based approaches (e.g. power law, Pareto, log-normal) are used to predict the global lake abundance in each size category. Only, Lehner and Döll (2004, Journal of Hydrology, 296, 1-22) provided a substantial canonical GIS platform called Global Lake and Wetland Database (GLWD) which combines different data sources such inventories, registers, archives, but also remote sensing acquisitions for various sensor types. Despite all these efforts there is still no accurate global sensus of inland waters. Satellite remote sensing is the only practical way to determine the spatial and temporal patterns of inland water on a large scale. Such inventory requires at least a precise enumeration and measurements including basically: (1) the geographical distribution (latitude and altitude); (2) the abundance, (3) the morphometric aspects (e.g., size, shape, mean depth, maximum depth, volume, or outlet elevation, etc.) of inland water bodies. We developed a semi-automatic and reproducible method over 8,500 Landsat 7 Enhanced Thematic Mapper Plus (ETM+) scenes also called GeoCover Circa2000. For this research, we proposed a "global" algorithm based on different aspects of digital images processing techniques which combined (1) the spectral signature and texture analysis for water body boundary delineation and (2) the Geographical Information System (GIS

  16. Research on HJ-1A/B satellite data automatic geometric precision correction design

    Institute of Scientific and Technical Information of China (English)

    Xiong Wencheng; Shen Wenming; Wang Qiao; Shi Yuanli; Xiao Rulin; Fu Zhuo

    2014-01-01

    Developed independently by China,HJ-1A/B satellites have operated well on-orbit for five years and acquired a large number of high-quality observation data. The realization of the observation data geometric precision correction is of great significance for macro and dynamic ecological environment monitoring. The pa-per analyzed the parameter characteristics of HJ-1 satellite and geometric features of HJ-1 satellite level 2 data (systematic geo-corrected data). Based on this,the overall HJ-1 multi-sensor geometric correction flow and charge-coupled device (CCD) automatic geometric precision correction method were designed. Actual operating data showed that the method could achieve good result for automatic geometric precision correction of HJ-1 sat-ellite data,automatic HJ-1 CCD image geometric precision correction accuracy could be achieved within two pixels and automatic matching accuracy between the images of same satellite could be obtained less than one pixel.

  17. User Experience Design in Professional Map-Based Geo-Portals

    Directory of Open Access Journals (Sweden)

    Bastian Zimmer

    2013-10-01

    Full Text Available We have recently been witnessing the growing establishment of map-centered web-based geo-portals on national, regional and local levels. However, a particular issue with these geo-portals is that each instance has been implemented in different ways in terms of design, usability, functionality, interaction possibilities, map size and symbologies. In this paper, we try to tackle these shortcomings by analyzing and formalizing the requirements for map-based geo-portals in a user experience based approach. First, we propose a holistic definition the term of a “geo-portal”. Then, we present our approach to user experience design for map-based geo-portals by defining the functional requirements of a geo-portal, by analyzing previous geo-portal developments, by distilling the results of our empirical user study to perform practically-oriented user requirements, and finally by establishing a set of user experience design guidelines for the creation of map-based geo-portals. These design guidelines have been extracted for each of the main components of a geo-portal, i.e., the map, the search dialogue, the presentation of the search results, symbologies, and other aspects. These guidelines shall constitute the basis for future geo-portal developments to achieve standardization in the user-experience design of map-based geo-portals.

  18. Handbook of satellite applications

    CERN Document Server

    Madry, Scott; Camacho-Lara, Sergio

    2017-01-01

    The first edition of this ground breaking reference work was the most comprehensive reference source available about the key aspects of the satellite applications field. This updated second edition covers the technology, the markets, applications and regulations related to satellite telecommunications, broadcasting and networking—including civilian and military systems; precise satellite navigation and timing networks (i.e. GPS and others); remote sensing and meteorological satellite systems. Created under the auspices of the International Space University based in France, this brand new edition is now expanded to cover new innovative small satellite constellations, new commercial launching systems, innovation in military application satellites and their acquisition, updated appendices, a useful glossary and more.

  19. Basic performance of BeiDou-2 navigation satellite system used in LEO satellites precise orbit determination

    Directory of Open Access Journals (Sweden)

    Liu Junhong

    2014-10-01

    Full Text Available The visibility for low earth orbit (LEO satellites provided by the BeiDou-2 system is analyzed and compared with the global positioning system (GPS. In addition, the spaceborne receivers’ observations are simulated by the BeiDou satellites broadcast ephemeris and LEO satellites orbits. The precise orbit determination (POD results show that the along-track component accuracy is much better over the service area than the non-service area, while the accuracy of the other two directions keeps at the same level over different areas. However, the 3-dimensional (3D accuracy over the two areas shows almost no difference. Only taking into consideration the observation noise and navigation satellite ephemeris errors, the 3D accuracy of the POD is about 30 cm. As for the precise relative orbit determination (PROD, the 3D accuracy is much better over the eastern hemisphere than that of the western hemisphere. The baseline length accuracy is 3.4 mm over the service area, and it is still better than 1 cm over the non-service area. This paper demonstrates that the BeiDou regional constellation could provide global service to LEO satellites for the POD and the PROD. Finally, the benefit of geostationary earth orbit (GEO satellites is illustrated for POD.

  20. Basic performance of BeiDou-2 navigation satellite system used in LEO satellites precise orbit determination

    Institute of Scientific and Technical Information of China (English)

    Liu Junhong; Gu Defeng; Ju Bing; Yao Jing; Duan Xiaojun; Yi Dongyun

    2014-01-01

    The visibility for low earth orbit (LEO) satellites provided by the BeiDou-2 system is analyzed and compared with the global positioning system (GPS). In addition, the spaceborne receivers’ observations are simulated by the BeiDou satellites broadcast ephemeris and LEO satel-lites orbits. The precise orbit determination (POD) results show that the along-track component accuracy is much better over the service area than the non-service area, while the accuracy of the other two directions keeps at the same level over different areas. However, the 3-dimensional (3D) accuracy over the two areas shows almost no difference. Only taking into consideration the observation noise and navigation satellite ephemeris errors, the 3D accuracy of the POD is about 30 cm. As for the precise relative orbit determination (PROD), the 3D accuracy is much better over the eastern hemisphere than that of the western hemisphere. The baseline length accuracy is 3.4 mm over the service area, and it is still better than 1 cm over the non-service area. This paper demon-strates that the BeiDou regional constellation could provide global service to LEO satellites for the POD and the PROD. Finally, the benefit of geostationary earth orbit (GEO) satellites is illustrated for POD.

  1. A satellite observation system simulation experiment for carbon monoxide in the lowermost troposphere

    Science.gov (United States)

    Edwards, David P.; Arellano, Avelino F.; Deeter, Merritt N.

    2009-07-01

    We demonstrate the feasibility of using observing system simulation experiment (OSSE) studies to help define quantitative trace gas measurement requirements for satellite missions and to evaluate the expected performance of proposed observing strategies. The 2007 U.S. National Research Council Decadal Survey calls for a geostationary (GEO) satellite mission for atmospheric composition and air quality applications (Geostationary Coastal and Air Pollution Events Mission (GEO-CAPE)). The requirement includes a multispectral (near-infrared and thermal infrared) measurement of carbon monoxide (CO) at high spatiotemporal resolution with information on lowermost troposphere concentration. We present an OSSE to assess the improvement in surface CO characterization that would result from the addition of a GEO-CAPE CO measurement to current low Earth orbit (LEO) thermal infrared-only measurements. We construct instrument simulators for these two measurement scenarios and study the case of July 2004 when wildfires in Alaska and Canada led to significant CO pollution over the contiguous United States. Compared to a control experiment, an ensemble-based data assimilation of simulated satellite observations in a global model leads to improvements in both the surface CO distributions and the time evolution of CO profiles at locations affected by wildfire plumes and by urban emissions. In all cases, an experiment with the GEO-CAPE CO measurement scenario (overall model skill of 0.84) performed considerably better than the experiment with the current LEO/thermal infrared measurement (skill of 0.58) and the control (skill of 0.07). This demonstrates the advantages of increased sampling from GEO and enhanced measurement sensitivity to the lowermost troposphere with a multispectral retrieval.

  2. Construction of a Matched Global Cloud and Radiance Product from LEO/GEO and EPIC Observations to Estimate Daytime Earth Radiation Budget from DSCOVR

    Science.gov (United States)

    Duda, David P.; Khlopenkov, Konstantin V.; Thiemann, Mandana; Palikonda, Rabindra; Sun-Mack, Sunny; Minnis, Patrick; Su, Wenying

    2016-01-01

    With the launch of the Deep Space Climate Observatory (DSCOVR), new estimates of the daytime Earth radiation budget can be computed from a combination of measurements from the two Earth-observing sensors onboard the spacecraft, the Earth Polychromatic Imaging Camera (EPIC) and the National Institute of Standards and Technology Advanced Radiometer (NISTAR). Although these instruments can provide accurate top-of-atmosphere (TOA) radiance measurements, they lack sufficient resolution to provide details on small-scale surface and cloud properties. Previous studies have shown that these properties have a strong influence on the anisotropy of the radiation at the TOA, and ignoring such effects can result in large TOA-flux errors. To overcome these effects, high-resolution scene identification is needed for accurate Earth radiation budget estimation. Selected radiance and cloud property data measured and derived from several low earth orbit (LEO, including NASA Terra and Aqua MODIS, NOAA AVHRR) and geosynchronous (GEO, including GOES (east and west), METEOSAT, INSAT-3D, MTSAT-2, and HIMAWARI-8) satellite imagers were collected to create hourly 5-km resolution global composites of data necessary to compute angular distribution models (ADM) for reflected shortwave (SW) and longwave (LW) radiation. The satellite data provide an independent source of radiance measurements and scene identification information necessary to construct ADMs that are used to determine the daytime Earth radiation budget. To optimize spatial matching between EPIC measurements and the high-resolution composite cloud properties, LEO/GEO retrievals within the EPIC fields of view (FOV) are convolved to the EPIC point spread function (PSF) in a similar manner to the Clouds and the Earth's Radiant Energy System (CERES) Single Scanner Footprint TOA/Surface Fluxes and Clouds (SSF) product. Examples of the merged LEO/GEO/EPIC product will be presented, describing the chosen radiance and cloud properties and

  3. Galileo satellite antenna modeling

    Science.gov (United States)

    Steigenberger, Peter; Dach, Rolf; Prange, Lars; Montenbruck, Oliver

    2015-04-01

    The space segment of the European satellite navigation system Galileo currently consists of six satellites. Four of them belong to the first generation of In-Orbit Validation (IOV) satellites whereas the other two are Full Operational Capability (FOC) satellites. High-precision geodetic applications require detailed knowledge about the actual phase center of the satellite and receiver antenna. The deviation of this actual phase center from a well-defined reference point is described by phase center offsets (PCOs) and phase center variations (PCVs). Unfortunately, no public information is available about the Galileo satellite antenna PCOs and PCVs, neither for the IOV, nor the FOC satellites. Therefore, conventional values for the IOV satellite antenna PCOs have been adopted for the Multi-GNSS experiment (MGEX) of the International GNSS Service (IGS). The effect of the PCVs is currently neglected and no PCOs for the FOC satellites are available yet. To overcome this deficiency in GNSS observation modeling, satellite antenna PCOs and PCVs are estimated for the Galileo IOV satellites based on global GNSS tracking data of the MGEX network and additional stations of the legacy IGS network. Two completely independent solutions are computed with the Bernese and Napeos software packages. The PCO and PCV values of the individual satellites are analyzed and the availability of two different solutions allows for an accuracy assessment. The FOC satellites are built by a different manufacturer and are also equipped with another type of antenna panel compared to the IOV satellites. Signal transmission of the first FOC satellite has started in December 2014 and activation of the second satellite is expected for early 2015. Based on the available observations PCO estimates and, optionally PCVs of the FOC satellites will be presented as well. Finally, the impact of the new antenna model on the precision and accuracy of the Galileo orbit determination is analyzed.

  4. BeiDou satellite's differential code biases estimation based on uncombined precise point positioning with triple-frequency observable

    Science.gov (United States)

    Fan, Lei; Li, Min; Wang, Cheng; Shi, Chuang

    2017-02-01

    The differential code bias (DCB) of BeiDou satellite is an important topic to make better use of BeiDou system (BDS) for many practical applications. This paper proposes a new method to estimate the BDS satellite DCBs based on triple-frequency uncombined precise point positioning (UPPP). A general model of both triple-frequency UPPP and Geometry-Free linear combination of Phase-Smoothed Range (GFPSR) is presented, in which, the ionospheric observable and the combination of triple-frequency satellite and receiver DCBs (TF-SRDCBs) are derived. Then the satellite and receiver DCBs (SRDCBs) are estimated together with the ionospheric delay that is modeled at each individual station in a weighted least-squares estimator, and the satellite DCBs are determined by introducing the zero-mean condition of all available BDS satellites. To validate the new method, 90 day's real tracking GNSS data (from January to March in 2014) collected from 9 Multi-GNSS Experiment (MGEX) stations (equipped with Trimble NETR9 receiver) is used, and the BDS satellite DCB products from German Aerospace Center (DLR) are taken as reference values for comparison. Results show that the proposed method is able to precisely estimate BDS satellite DCBs: (1) the mean value of the day-to-day scattering for all available BDS satellites is about 0.24 ns, which is reduced in average by 23% when compared with the results derived by only GFPSR. Moreover, the mean value of the day-to-day scattering of IGSO satellites is lower than that of GEO and MEO satellites; (2) the mean value of RMS of the difference with respect to DLR DCB products is about 0.39 ns, which is improved by an average of 11% when compared with the results derived by only GFPSR. Besides, the RMS of IGSO and MEO satellites is at the same level which is better than that of GEO satellites.

  5. The Rigorous Geometric Model of Satellite Laser Altimeter and Preliminarily Accuracy Validation

    Directory of Open Access Journals (Sweden)

    TANG Xinming

    2016-10-01

    Full Text Available It has been paid attention to improving the elevation accuracy of satellite stereo images aided by laser altimeter. The GF-7 satellite scheduled to launch in 2018 will be equipped with optical stereo cameras and a laser altimeter. ICESat (Ice, Cloud, and land Elevation Satellite with GLAS(Geo-science Laser Altimeter System is the first and still only laser altimeter satellite for earth observation until now. In this paper, the comprehensively analysis about the rigorous geometric model and accuracy analysis of laser altimeter is presented. The error induced by laser pointing aberration and mounting is proposed, and the data processing workflow of ICESat/GLAS from level 0 to level 2 is introduced. What's more, the geo-location accuracy between this paper and GLAS product is compared and the model is validated by the result that the accuracy based on the model is about 3 cm and 11 cm in the horizontal and vertical direction, respectively. The laser altimeter data loaded on the ZY3-02 satellite has been processed and validated preliminarily. The conclusion of this paper is valuable and can be viewed as reference for the subsequent domestic laser altimeter satellites.

  6. A Novel Method for Satellite Maneuver Prediction

    Science.gov (United States)

    Shabarekh, C.; Kent-Bryant, J.; Keselman, G.; Mitidis, A.

    2016-09-01

    A space operations tradecraft consisting of detect-track-characterize-catalog is insufficient for maintaining Space Situational Awareness (SSA) as space becomes increasingly congested and contested. In this paper, we apply analytical methodology from the Geospatial-Intelligence (GEOINT) community to a key challenge in SSA: predicting where and when a satellite may maneuver in the future. We developed a machine learning approach to probabilistically characterize Patterns of Life (PoL) for geosynchronous (GEO) satellites. PoL are repeatable, predictable behaviors that an object exhibits within a context and is driven by spatio-temporal, relational, environmental and physical constraints. An example of PoL are station-keeping maneuvers in GEO which become generally predictable as the satellite re-positions itself to account for orbital perturbations. In an earlier publication, we demonstrated the ability to probabilistically predict maneuvers of the Galaxy 15 (NORAD ID: 28884) satellite with high confidence eight days in advance of the actual maneuver. Additionally, we were able to detect deviations from expected PoL within hours of the predicted maneuver [6]. This was done with a custom unsupervised machine learning algorithm, the Interval Similarity Model (ISM), which learns repeating intervals of maneuver patterns from unlabeled historical observations and then predicts future maneuvers. In this paper, we introduce a supervised machine learning algorithm that works in conjunction with the ISM to produce a probabilistic distribution of when future maneuvers will occur. The supervised approach uses a Support Vector Machine (SVM) to process the orbit state whereas the ISM processes the temporal intervals between maneuvers and the physics-based characteristics of the maneuvers. This multiple model approach capitalizes on the mathematical strengths of each respective algorithm while incorporating multiple features and inputs. Initial findings indicate that the combined

  7. Cost-benefit analysis for commissioning decisions in GEO600

    CERN Document Server

    Adams, T; Slutsky, J; Was, M; Affeldt, C; Degallaix, J; Dooley, K L; Grote, H; Hild, S; Lueck, H; Macleod, D M; Nuttall, L K; Prijatelj, M; Schreiber, E; Sorazu, B; Strain, K A; Sutton, P J; Vahlbruch, H; Witte, H; Danzmann, K

    2015-01-01

    Gravitational wave interferometers are complex instruments, requiring years of commissioning to achieve the required sensitivities for the detection of gravitational waves, of order 10^-21 in dimensionless detector strain, in the tens of Hz to several kHz frequency band. Investigations carried out by the GEO600 detector characterisation group have shown that detector characterisation techniques are useful when planning for commissioning work. At the time of writing, GEO600 is the only large scale laser interferometer currently in operation running with a high duty factor, 70%, limited chiefly by the time spent commissioning the detector. The number of observable gravitational wave sources scales as the product of the volume of space to which the detector is sensitive and the observation time, so the goal of commissioning is to improve the detector sensitivity with the least possible detector down time. We demonstrate a method for increasing the number of sources observable by such a detector, by assessing the...

  8. The role of geo-based technology in place experiences

    DEFF Research Database (Denmark)

    Tussyadiah, Iis; Zach, F.J.

    2012-01-01

    Today, as various context-aware technologies have become increasingly ubiquitous, tourists have access to retrieve voluminous geographic information about tourism destinations. These technologies are suggested to aid tourists in gaining meaningful experiences with places. This study identifies how...... the use of geo-based technology plays a role in the acquisition of geographic knowledge and behavior. It is identified that the use of geo-based technology while traveling contributes to the different components that frame the structure of tourism experience. Further, this study also confirms that tourism...... experience can be seen as a part of the everyday experience as geographic behavior exhibited on a day-to-day basis is found to have an effect on tourism experience....

  9. The modecleaner system and suspension aspects of GEO 600

    Energy Technology Data Exchange (ETDEWEB)

    Gossler, S [Universitaet Hannover, Institut fuer Atom-und Molekuelphysik, Abteilung Spektroskopie, Callinstrasse 38, D-30169 Hannover (Germany); Casey, M M [Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Freise, A [Universitaet Hannover, Institut fuer Atom-und Molekuelphysik, Abteilung Spektroskopie, Callinstrasse 38, D-30169 Hannover (Germany); Grote, H [Universitaet Hannover, Institut fuer Atom-und Molekuelphysik, Abteilung Spektroskopie, Callinstrasse 38, D-30169 Hannover (Germany); Lueck, H [Universitaet Hannover, Institut fuer Atom-und Molekuelphysik, Abteilung Spektroskopie, Callinstrasse 38, D-30169 Hannover (Germany); McNamara, P [Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Plissi, M V [Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Robertson, D I [Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Robertson, N A [Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Skeldon, K [Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Strain, K A [Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Torrie, C I [Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Ward, H [Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Willke, B [Max-Planck Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Teilinstitut Hannover, Callinstrasse 38, D-30169 Hannover (Germany); Hough, J [Department of Physics and Astronomy, Kelvin Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom)] [and others

    2002-04-07

    GEO 600 uses two 8 m triangular ring cavities as a modecleaner system for the stabilization of the laser. To isolate the cavities with respect to the seismic noise the optical components are suspended as double pendulums. The resonances of these pendulums are damped by a local-control loop via magnet-coil actuators acting on the intermediate masses. The suspension scheme and the measured key data (i.e. finesse, linewidth, visibility, throughput and in-lock durations of the cavities, as well as the isolation performance and the resulting frequency stability) of the modecleaner system will be given in this paper. Furthermore an overview of the GEO 600 interferometer suspension will be given.

  10. The proto-Earth geo-reactor: Reassessing the hypotheses

    Directory of Open Access Journals (Sweden)

    Claude Degueldre

    2016-09-01

    The present paper focuses on the geo-reactor hypothetical conditions including history, spatial extension and regimes. The discussion based on recent calculations involves investigations on the limits in term of fissile inventory, size and power, based on coupling of geochemical reactions and stratification through the gravitational field considering behavior through the inner mantle, the boundary with the core and the core. The reconstruction allows to formulating that from the history point of view it would have been possible that the geo-reactor reached criticality in a proto-Earth period as a reactor triggered by 235-uranium and that thorium may have worked as an absorber if the actinide concentration was locally large enough. Without actinide separation the initiation of the criticality is unlikely. However did the segregation of actinides occur in any Earth layer?

  11. Progress in Geo-Electrical Methods for Hydrogeological Mapping?

    DEFF Research Database (Denmark)

    Schrøder, Niels

    2014-01-01

    In most of the 20th century the geo-electrical methods were primarily used for groundwater exploration and the application of the methods were normally followed by a borehole, and a moment of truth. In this process the use of DC (direct current) soundings have been developed to a high grade...... of excellence. In the last 25 years the geo-electrical methods are more used in connection with groundwater protection and planning, and new methods, as transient electromagnetic (TEM) soundings, have been developed that provide more measurements per hour. In Denmark this change is very explicit, and a paper....... The test area was earlier mapped by DC-soundings, so it is possible to test the methods against each other. It is concluded that well performed DC-soundings with a Schlumberger configuration still provide the best base for hydrogeological mapping...

  12. GeoChips for Analysis of Microbial Functional Communities

    Energy Technology Data Exchange (ETDEWEB)

    Van Nostrand, Joy D.; Wu, Liyou; He, Zhili; Zhou, Jizhong

    2008-09-30

    Functional gene arrays (FGA) are microarrays that contain probes for genes encoding proteins or enzymes involved in functions of interest and allow for the study of thousands of genes at one time. The most comprehensive FGA to date is the GeoChip, which contains ~;;24,000 probes for ~;;10,000 genes involved in the geochemical cycling of C, N, P, and S, as well as genes involved in metal resistance and reduction and contaminant degradation. This chapter details the methods necessary for GeoChip analysis. Methods covered include preparation of DNA (whole community genome amplification and labeling), array setup (prehybridization steps), hybridization (sample and hybridization buffers), and post hybridization steps (slide washing and array scanning).

  13. The modecleaner system and suspension aspects of GEO 600

    CERN Document Server

    Gossler, S; Freise, A; Grote, H; Lück, H B; McNamara, P; Plissi, M V; Robertson, D I; Robertson, N A; Skeldon, K D; Strain, K A; Torrie, C I; Ward, H; Willke, B; Hough, J; Danzmann, K

    2002-01-01

    GEO 600 uses two 8 m triangular ring cavities as a modecleaner system for the stabilization of the laser. To isolate the cavities with respect to the seismic noise the optical components are suspended as double pendulums. The resonances of these pendulums are damped by a local-control loop via magnet-coil actuators acting on the intermediate masses. The suspension scheme and the measured key data (i.e. finesse, linewidth, visibility, throughput and in-lock durations of the cavities, as well as the isolation performance and the resulting frequency stability) of the modecleaner system will be given in this paper. Furthermore an overview of the GEO 600 interferometer suspension will be given.

  14. Potential of Geo-neutrino Measurements at JUNO

    CERN Document Server

    Han, Ran; Zhan, Liang; McDonough, William F; Cao, Jun

    2015-01-01

    The flux of geoneutrinos at any point on the Earth is a function of the abundance and distribution of radioactive elements within our planet. This flux has been successfully detected by the 1-kt KamLAND and 0.3-kt Borexino detectors with these measurements being limited by their low statistics. The planned 20-kt JUNO detector will provide an exciting opportunity to obtain a high statistics measurement, which will provide data to address several questions of geological importance. This paper presents the JUNO detector design concept, the expected geo-neutrino signal and corresponding backgrounds. The precision level of geo-neutrino measurements at JUNO is obtained with the standard least-squares method. The potential of the Th/U ratio and mantle measurements is also discussed.

  15. Teaching GeoEthics Across the Geoscience Curriculum

    Science.gov (United States)

    Mogk, D. W.; Geissman, J. W.; Kieffer, S. W.; Reidy, M.; Taylor, S.; Vallero, D. A.; Bruckner, M. Z.

    2014-12-01

    Ethics education is an increasingly important component of the pre-professional training of geoscientists. Funding agencies (NSF) require training of graduate students in the responsible conduct of research, employers are increasingly expecting their workers to have basic training in ethics, and the public demands that scientists abide by the highest standards of ethical conduct. Yet, few faculty have the requisite training to effectively teach about ethics in their classes, or even informally in mentoring their research students. To address this need, an NSF-funded workshop was convened to explore how ethics education can be incorporated into the geoscience curriculum. Workshop goals included: examining where and how geoethics topics can be taught from introductory courses for non-majors to modules embedded in "core" geoscience majors courses or dedicated courses in geoethics; sharing best pedagogic practices for "what works" in ethics education; developing a geoethics curriculum framework; creating a collection of online instructional resources, case studies, and related materials; applying lessons learned about ethics education from sister disciplines (biology, engineering, philosophy); and considering ways that geoethics instruction can contribute to public scientific literacy. Four major themes were explored in detail: (1) GeoEthics and self: examining the internal attributes of a geoscientist that establish the ethical values required to successfully prepare for and contribute to a career in the geosciences; (2) GeoEthics and the geoscience profession: identifying ethical standards expected of geoscientists if they are to contribute responsibly to the community of practice; (3) GeoEthics and society: exploring geoscientists' responsibilities to effectively and responsibly communicate the results of geoscience research to inform society about issues ranging from geohazards to natural resource utilization in order to protect public health, safety, and economic

  16. Semantic web and the concept of global geo-ontology

    OpenAIRE

    Čeh, Marjan; Smole, Domen; Podobnikar, Tomaž

    2013-01-01

    Geographic information systems have been applied on the World Wide Web with different approaches and there is a need to recognize how different groups of users conceptualize the domain of geographic space. In our research, we present an attempt to model a semantic reference system in a semantic web by the concept of global geo-ontology. Taxonomy is based on general knowledge representation as physical and conceptual shapes, simultaneously with basic and advanced hum...

  17. Data acquisition and detector characterization of GEO600

    CERN Document Server

    Koetter, K; Babak, S; Balasubramanian, R; Berukoff, S; Bose, S; Churches, D; Colacino, C N; Cutler, C; Danzmann, K; Davies, R; Dupuis, R; Freise, A; Grote, H; Heinzel, G; Hewitson, M; Hough, J; Lück, H B; Malec, M; Mohanty, S D; Mukherjee, S; Nagano, S; Papa, M A; Robertson, D; Sathyaprakash, B S; Schutz, B F; Sintes, A M; Strain, K A; Taylor, I J; Vecchio, A; Ward, H; Weiland, U; Willke, B; Woan, G

    2002-01-01

    The data acquisition system of the gravitational wave detector GEO600 is recording the first data now. Data from detector subsystems and environmental channels are being acquired. The data acquisition system is described and first results from the detector characterization work are being presented. We analysed environmental influences on the detector to determine noise propagation through the detector. Long-term monitoring allowed us to see long-timescale drifts in subsystems.

  18. Development of geo-electrical meter based on networking

    Institute of Scientific and Technical Information of China (English)

    WANG Lan-wei; ZHAO Jia-liu

    2008-01-01

    Further development of earthquake equipments is closely associated with that of computer technology. Because Embedded PC104 module has the equivalent functions of PC, it has been widely used in recent years, and can provide a new and flexible hardware design environment, but its applications in observation instruments of earthquake precursor are rare. The present paper introduces in detail the realization of a networked geo-electrical meter by applying the low price, high reliability embedded PC 104 industrial computer.

  19. Via GeoAlpina - an international project of IYPE

    Science.gov (United States)

    Piller, Werner E.

    2010-05-01

    Mountainous areas show earth science features in a very conspicuous, frequently even in a spectacular way. Because of the general perception of the beauty of mountains many mountainous regions are well developed in terms of trails and touristic infrastructure. Therefore, mountains are a key area to bring earth sciences closer to people. In many mountain chains all over the world (e.g., Alps, Pyrenees, Andes, Rocky Mountains) far-ranging walking and hiking trails are developed to serve a broad audience. To provide this audience with basic information in geological phenomena along such trails the project "Via Geo..." was born as an international activity within the International Year of Planet Earth. The Alps have been selected to act as a pilot project with six Alpine nations participating: Austria, France, Germany, Italy, Slovenia, and Switzerland. Many well maintained trails exist bridging the Alps from the Adriatic Sea in Trieste (Italy) to Monte Carlo (Monaco) in the Western Mediterranean. Some of these trails are included in the project "Via Alpina". The idea of Via GeoAlpina is to point at geological attractions along the trails of Via Alpina or in their vicinity and offer simple but striking information. Various earth science fields will be covered, such as geology, geophysics, paleontology, mineralogy, hydrogeology, pedology, climatology, and geomorphology. The trail descriptions can be accessed and downloaded from the Via GeoAlpina website. In 2009 every country inaugurated Via GeoAlpina on a national base with a particular opening event in the presence of local authorities and local and national media. These events were accompanied with the distribution of flyers, by offering guided tours and by installation of panels in the field. These activities, however, should be followed by even more actions in the following years. These follow-ups should attract local and regional authorities at state, county or village level and will ideally be financed by private

  20. Museum of Wangwu Mountain International Geo-park

    Institute of Scientific and Technical Information of China (English)

    Baofeng LI; Weining ZHANG

    2008-01-01

    The design for Wangwu Mountain Geological Park Museum emphasizes protecting terrain, geomorpho-logy and natural vegetation, utilization of local materials and traditional craftsmanship, and integrates multi-spe-cialty design into a whole. The idea of green architecture organically guides the designer to create a museum in a remote mountain and creates a special place that is geo-logically significant in architectural language.

  1. GeoDCAT-AP: Use cases and open issues

    OpenAIRE

    PEREGO ANDREA; FRIIS-CHRISTENSEN Anders; Lutz, Michael

    2016-01-01

    This paper illustrates some issues and use cases identified during the design and implementation of GeoDCAT-AP, a metadata profile aiming to provide a representation of geospatial metadata compliant with the DCAT application profile for European data portals (DCAT-AP). In particular, the paper focuses on those issues that may have a possible relevance also outside the geospatial domain, covering topics concerning metadata profile-based negotiation, publishing metadata on the Web, represen...

  2. Satellite-Delivered Learning.

    Science.gov (United States)

    Arnall, Gail C.

    1987-01-01

    Discusses the application of satellite information delivery to training. Describes a new trend, horizontal programming. Also discusses vertical programming and in-house production of training materials. Lists vendors of satellite-based training. (CH)

  3. GPS Satellite Simulation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The GPS satellite simulation facility consists of a GPS satellite simulator controlled by either a Silicon Graphics Origin 2000 or PC depending upon unit under test...

  4. China's Recoverable Satellites

    Institute of Scientific and Technical Information of China (English)

    Tang Boehang

    2008-01-01

    @@ By the end of 2006, China had launched 24 recoverable satellites (FSW) in total. Among them, 23 were launched successfully, of which all but one were successfully recovered. Recoverable satellites launched by China are listed in Table 1.

  5. Satellite Tags- Hawaii EEZ

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Satellite tagging was implemented in 2013. Satellite tagging is conducted using a Dan Inject air rifle and deployment arrows designed by Wildlife Computers. Two...

  6. Geo-environmental mapping tool applied to pipeline design

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Karina de S.; Calle, Jose A.; Gil, Euzebio J. [Geomecanica S/A Tecnologia de Solo Rochas e Materiais, Rio de Janeiro, RJ (Brazil); Sare, Alexandre R. [Geomechanics International Inc., Houston, TX (United States); Soares, Ana Cecilia [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The Geo-Environmental Mapping is an improvement of the Geological-Geotechnical Mapping used for basic pipeline designs. The main purpose is to assembly the environmental, geotechnical and geological concepts in a methodological tool capable to predict constrains and reduce the pipeline impact to the environment. The Geo-Environmental mapping was built to stress the influence of soil/structure interaction, related to the physical effect that comes from the contact between structures and soil or rock. A Geological-Geotechnical-Environmental strip (chart) was presented to emphasize the pipeline operational constrains and its influence to the environment. The mapping was developed to clearly show the occurrence and properties of geological materials divided into geotechnical domain units (zones). The strips present construction natural properties, such as: excavability, stability of the excavation and soil re-use capability. Also, the environmental constrains were added to the geological-geotechnical mapping. The Geo-Environmental Mapping model helps the planning of the geotechnical and environmental inquiries to be carried out during executive design, the discussion on the types of equipment to be employed during construction and the analysis of the geological risks and environmental impacts to be faced during the built of the pipeline. (author)

  7. TASK ALLOCATION IN GEO-DISTRIBUTATED CYBER-PHYSICAL SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, Rachel; Smidts, Carol

    2017-03-01

    This paper studies the task allocation algorithm for a distributed test facility (DTF), which aims to assemble geo-distributed cyber (software) and physical (hardware in the loop components into a prototype cyber-physical system (CPS). This allows low cost testing on an early conceptual prototype (ECP) of the ultimate CPS (UCPS) to be developed. The DTF provides an instrumentation interface for carrying out reliability experiments remotely such as fault propagation analysis and in-situ testing of hardware and software components in a simulated environment. Unfortunately, the geo-distribution introduces an overhead that is not inherent to the UCPS, i.e. a significant time delay in communication that threatens the stability of the ECP and is not an appropriate representation of the behavior of the UCPS. This can be mitigated by implementing a task allocation algorithm to find a suitable configuration and assign the software components to appropriate computational locations, dynamically. This would allow the ECP to operate more efficiently with less probability of being unstable due to the delays introduced by geo-distribution. The task allocation algorithm proposed in this work uses a Monte Carlo approach along with Dynamic Programming to identify the optimal network configuration to keep the time delays to a minimum.

  8. Gps-Denied Geo-Localisation Using Visual Odometry

    Science.gov (United States)

    Gupta, Ashish; Chang, Huan; Yilmaz, Alper

    2016-06-01

    The primary method for geo-localization is based on GPS which has issues of localization accuracy, power consumption, and unavailability. This paper proposes a novel approach to geo-localization in a GPS-denied environment for a mobile platform. Our approach has two principal components: public domain transport network data available in GIS databases or OpenStreetMap; and a trajectory of a mobile platform. This trajectory is estimated using visual odometry and 3D view geometry. The transport map information is abstracted as a graph data structure, where various types of roads are modelled as graph edges and typically intersections are modelled as graph nodes. A search for the trajectory in real time in the graph yields the geo-location of the mobile platform. Our approach uses a simple visual sensor and it has a low memory and computational footprint. In this paper, we demonstrate our method for trajectory estimation and provide examples of geolocalization using public-domain map data. With the rapid proliferation of visual sensors as part of automated driving technology and continuous growth in public domain map data, our approach has the potential to completely augment, or even supplant, GPS based navigation since it functions in all environments.

  9. Satellite communication engineering

    CERN Document Server

    Kolawole, Michael Olorunfunmi

    2013-01-01

    An undeniably rich and thorough guide to satellite communication engineering, Satellite Communication Engineering, Second Edition presents the fundamentals of information communications systems in a simple and succinct way. This book considers both the engineering aspects of satellite systems as well as the practical issues in the broad field of information transmission. Implementing concepts developed on an intuitive, physical basis and utilizing a combination of applications and performance curves, this book starts off with a progressive foundation in satellite technology, and then moves on

  10. Taiyuan Satellite Launch Center

    Institute of Scientific and Technical Information of China (English)

    LiuJie

    2004-01-01

    There are three major space launch bases in China, the Jiuquan Satellite Launch Center,the Taiyuan Satellite Launch Center and the Xichang Satellite Launch Center. All the three launch centers are located in sparsely populated areas where the terrain is even and the field of vision is broad. Security, transport conditions and the influence of the axial rotation

  11. Geodetic Secor Satellite

    Science.gov (United States)

    1974-06-01

    simple, and had low-power lem. 17 14. Satellite Orientation . The satellite was designed to maintain a constant relationship between the antenna...the same satellite orientation . Further considerations were Th oscillations, however, when higher orbital ranges (500-2500 nautical miles) -, 3 a

  12. TC-2 Satellite Delivered

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    On April 18, 2005, TC-2, the second satellite of Double Star Program (DSP), which was jointly developed by CNSA and ESA, was approved to be delivered to the user after the on-board test and trial operation. The satellite is working well and the performance can meet the user's need. The satellite has collected large amount of valuable scientific data

  13. Satellite-Friendly Protocols and Standards

    Science.gov (United States)

    Koudelka, O.; Schmidt, M.; Ebert, J.; Schlemmer, H.; Kastner, S.; Riedler, W.

    2002-01-01

    We are currently observing a development unprecedented with other services, the enormous growth of the Internet. Video, voice and data applications can be supported via this network in high quality. Multi-media applications require high bandwidth which may not be available in many areas. When making proper use of the broadcast feature of a communications satellite, the performance of the satellite-based system can compare favourably to terrestrial solutions. Internet applications are in many cases highly asymmetric, making them very well suited to applications using small and inexpensive terminals. Data from one source may be used simultaneously by a large number of users. The Internet protocol suite has become the de-facto standard. But this protocol family in its original form has not been designed to support guaranteed quality of service, a prerequisite for real-time, high quality traffic. The Internet Protocol has to be adapted for the satellite environment, because long roundtrip delays and the error behaviour of the channel could make it inefficient over a GEO satellite. Another requirement is to utilise the satellite bandwidth as efficiently as possible. This can be achieved by adapting the access system to the nature of IP frames, which are variable in length. In the framework of ESA's ARTES project a novel satellite multimedia system was developed which utilises Multi-Frequency TDMA in a meshed network topology. The system supports Quality of Service (QoS) by reserving capacity with different QoS requirements. The system is centrally controlled by a master station with the implementation of a demand assignment (DAMA) system. A lean internal signalling system has been adopted. Network management is based on the SNMP protocol and industry-standard network management platforms, making interfaces to standard accounting and billing systems easy. Modern communication systems will have to be compliant to different standards in a very flexible manner. The

  14. 基于GeoStudio边坡稳定性分析%Slope Stability Analysis Based on GeoStudio

    Institute of Scientific and Technical Information of China (English)

    胡海; 陈玉明; 玉尖地

    2016-01-01

    本文主要通过GeoStudio软件分析A排土场边坡稳定性,为该排土场在生产上提供理论上的技术基础,通过技术分析研究了该排土场的安全性,降低了安全事故发生的概率。%This article mainly analyzes the slope stability of A refuse dump through GeoStudio, so as to provide theoretical basis for the production of the dump. Through technical analysis, the safety of the dump is analyzed and the probability of safety accidents is reduced.

  15. A global satellite-assisted precipitation climatology

    Science.gov (United States)

    Funk, C.; Verdin, A.; Michaelsen, J.; Peterson, P.; Pedreros, D.; Husak, G.

    2015-10-01

    Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti) are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high-resolution (0.05°) global precipitation climatologies that perform reasonably well in data-sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology, the Climate

  16. A global satellite assisted precipitation climatology

    Directory of Open Access Journals (Sweden)

    C. Funk

    2015-05-01

    Full Text Available Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high resolution (0.05° global precipitation climatologies that perform reasonably well in data sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology

  17. A global satellite assisted precipitation climatology

    Science.gov (United States)

    Funk, Christopher C.; Verdin, Andrew P.; Michaelsen, Joel C.; Pedreros, Diego; Husak, Gregory J.; Peterson, P.

    2015-01-01

    Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti) are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high resolution (0.05°) global precipitation climatologies that perform reasonably well in data sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology, the Climate

  18. Via GeoAlpina - an international project of IYPE (Invited)

    Science.gov (United States)

    Piller, W. E.

    2009-12-01

    Mountainous areas show geological features in a very conspicuous, frequently even in a spectacular way. Because of the general perception of the beauty of mountains many mountainous regions are well developed in terms of touristic infrastructure and accessibility. Therefore, mountains are a key area to bring earth sciences closer to people. In many mountain chains all over the world (e.g., Alps, Pyrenees, Andes, Rocky Mountains, Himalayas) far-ranging walking and hiking trails are developed to serve a broad spectrum of activists. To supply this audience with basic information about geological phenomena and processes along such trails the project “Via Geo...” was born as an international activity within the International Year of Planet Earth. This approach may and should be applied in different parts of the world. The Alps have been selected to act in a pilot project with six Alpine nations participating in “Via GeoAlpina”: Austria, France, Germany, Italy, Slovenia, and Switzerland. This is due to the fact that a wealth of well maintained trails and touristic infrastructure exists all over the Alps. Some of these are included in the project “Via Alpina” bridging the entire mountain system from the Adriatic Sea at Trieste (Italy) to Monte Carlo (Monaco) in the Western Mediterranean. The idea of Via GeoAlpina is to point at geological attractions along the trails of Via Alpina or in their vicinity and to offer simple but clear-cut information on these features. Various earth science fields will be covered, such as geology, geophysics, paleontology, mineralogy, hydrogeology, pedology, climatology, and geomorphology. In addition, particular topics on applied earth science aspects, e.g, mineral recourses and geological hazards, which are of particular importance for society, will be addressed. This information is primarily web-based and trail descriptions can be accessed and downloaded from the Via GeoAlpina website (http://www.viageoalpina.org). In 2009

  19. The principle of the positioning system based on communication satellites

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    It is a long dream to realize the communication and navigation functionality in a satellite system in the world. This paper introduces how to establish the system, a positioning system based on communication satellites called Chinese Area Positioning System (CAPS). Instead of the typical navigation satellites, the communication satellites are configured firstly to transfer navigation signals from ground stations, and can be used to obtain service of the positioning, velocity and time, and to achieve the function of navigation and positioning. Some key technique issues should be first solved; they include the accuracy position determination and orbit prediction of the communication satellites, the measur- ing and calculation of transfer time of the signals, the carrier frequency drift in communication satellite signal transfer, how to improve the geometrical configuration of the constellation in the system, and the integration of navigation & communication. Several innovative methods are developed to make the new system have full functions of navigation and communication. Based on the development of crucial techniques and methods, the CAPS demonstration system has been designed and developed. Four communication satellites in the geosynchronous orbit (GEO) located at 87.5°E, 110.5°E, 134°E, 142°E and barometric altimetry are used in the CAPS system. The GEO satellites located at 134°E and 142°E are decommissioned GEO (DGEO) satellites. C-band is used as the navigation band. Dual frequency at C1=4143.15 MHz and C2=3826.02 MHz as well as dual codes with standard code (CA code and precision code (P code)) are adopted. The ground segment consists of five ground stations; the master station is in Lintong, Xi’an. The ground stations take a lot of responsibilities, including monitor and management of the operation of all system components, determination of the satellite position and prediction of the satellite orbit, accomplishment of the virtual atomic clock

  20. shinyGEO: a web-based application for analyzing gene expression omnibus datasets.

    Science.gov (United States)

    Dumas, Jasmine; Gargano, Michael A; Dancik, Garrett M

    2016-12-01

    The Gene Expression Omnibus (GEO) is a public repository of gene expression data. Although GEO has its own tool, GEO2R, for data analysis, evaluation of single genes is not straightforward and survival analysis in specific GEO datasets is not possible without bioinformatics expertise. We describe a web application, shinyGEO, that allows a user to download gene expression data sets directly from GEO in order to perform differential expression and survival analysis for a gene of interest. In addition, shinyGEO supports customized graphics, sample selection, data export and R code generation so that all analyses are reproducible. The availability of shinyGEO makes GEO datasets more accessible to non-bioinformaticians, promising to lead to better understanding of biological processes and genetic diseases such as cancer. Web application and source code are available from http://gdancik.github.io/shinyGEO/ CONTACT: dancikg@easternct.eduSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. Seamless Positioning and Navigation by Using Geo-Referenced Images and Multi-Sensor Data

    Directory of Open Access Journals (Sweden)

    Tao Li

    2013-07-01

    Full Text Available Ubiquitous positioning is considered to be a highly demanding application for today’s Location-Based Services (LBS. While satellite-based navigation has achieved great advances in the past few decades, positioning and navigation in indoor scenarios and deep urban areas has remained a challenging topic of substantial research interest. Various strategies have been adopted to fill this gap, within which vision-based methods have attracted growing attention due to the widespread use of cameras on mobile devices. However, current vision-based methods using image processing have yet to revealed their full potential for navigation applications and are insufficient in many aspects. Therefore in this paper, we present a hybrid image-based positioning system that is intended to provide seamless position solution in six degrees of freedom (6DoF for location-based services in both outdoor and indoor environments. It mainly uses visual sensor input to match with geo-referenced images for image-based positioning resolution, and also takes advantage of multiple onboard sensors, including the built-in GPS receiver and digital compass to assist visual methods. Experiments demonstrate that such a system can greatly improve the position accuracy for areas where the GPS signal is negatively affected (such as in urban canyons, and it also provides excellent position accuracy for indoor environments.

  2. Seamless positioning and navigation by using geo-referenced images and multi-sensor data.

    Science.gov (United States)

    Li, Xun; Wang, Jinling; Li, Tao

    2013-07-12

    Ubiquitous positioning is considered to be a highly demanding application for today's Location-Based Services (LBS). While satellite-based navigation has achieved great advances in the past few decades, positioning and navigation in indoor scenarios and deep urban areas has remained a challenging topic of substantial research interest. Various strategies have been adopted to fill this gap, within which vision-based methods have attracted growing attention due to the widespread use of cameras on mobile devices. However, current vision-based methods using image processing have yet to revealed their full potential for navigation applications and are insufficient in many aspects. Therefore in this paper, we present a hybrid image-based positioning system that is intended to provide seamless position solution in six degrees of freedom (6DoF) for location-based services in both outdoor and indoor environments. It mainly uses visual sensor input to match with geo-referenced images for image-based positioning resolution, and also takes advantage of multiple onboard sensors, including the built-in GPS receiver and digital compass to assist visual methods. Experiments demonstrate that such a system can greatly improve the position accuracy for areas where the GPS signal is negatively affected (such as in urban canyons), and it also provides excellent position accuracy for indoor environments.

  3. GEOS-2 observations of energetic electrons in the morning sector during auroral radio absorption events

    Energy Technology Data Exchange (ETDEWEB)

    Collis, P.N.; Korth, A.

    1985-04-01

    The temporal development of two auroral absorption events in the morning sector is compared with simultaneous observations of electrons from the satellite GEOS-2, utilizing the good energy resolution over the range 15-300 keV to show that the electrons effective in contributing to the observed radio absorption are confined to the range 30-130 keV. By far the most important are those below 80 keV, and as a geophysical monitor the riometer may be considered an efficient indicator of electron fluxes of energy typically of 60-70 keV. The ionospheric effects of the precipitated fluxes are predicted, and the results used to discuss the validity of the model atmosphere and of the profiles of effective recombination coefficient and specific absorption. Integration of the calculated profiles of incremental radio absorption yields total estimates within 30 percent of the observed intensities. The absorbing layer maximizes at altitudes of 85-90 km and has a typical half-height of 25 km. It is shown further that the electron-flux characteristics are consistent with gradient-curvature drift from a particle source in the midnight sector. 33 references.

  4. Military Hydrology. Report 8. Feasibility of Utilizing Satellite and Radar Data in Hydrologic Forecasting.

    Science.gov (United States)

    1985-09-01

    Keown , Chief, ECG, under the general super- vision of Dr. Lewis E. Link, Chief, ESD, and Dr. John Harrison, Chief, EL. During the preparation of this... Martin , D. W., Stout, J., and Sikdar, 1). N. 1976. "Rainfall Estimation from Geo- synchronous Satellite Imagery During Daylight Hours," NOAA...Technical Report ERL 356-WMPO 7, US Department of Commerce. Griffith, C. G., Woodley, W. L., Grube, P. G., Martin , D. W., Stout, J., and Sikdar. D. N. 1978

  5. Geo-Hazard Detection and Monitoring Using SAR and Optical Images in a Snow-Covered Area: The Menyuan (China Test Site

    Directory of Open Access Journals (Sweden)

    Qihuan Huang

    2017-09-01

    Full Text Available In this work, we combine SAR and optical images for geo-hazard detection and monitoring in Western China. An extremely small baseline of C-band SAR image pairs acquired from Sentinel-1A at Menyuan, China, is analyzed. Apart from the large area of coseismal deformation, we proposed an earthquake-derived landslide detecting method by removing the coseismal deformation with polynomial fitting, then the detected moving areas were confirmed with Chinese Gaofen-1 optical satellite images. Sentinel-1A C-band interferograms show about a 7-cm line of sight movement caused by the MS 6.4 Menyuan earthquake; meanwhile, several features indicative of ground movement were detected by the proposed method and demonstrated by the Gaofen-1 optical images; the interpretation of high-resolution optical data complemented the goal of better understanding the behavior of geo-hazard disasters. InSAR time series analysis provides an opportunity for continuous monitoring of geo-hazards in remote areas, while the optical image method is easily affected by decorrelation due to snowfall.

  6. Some Discussion on Geo-Hazards Control and Geo-Environment Sustainable Development%论地质灾害防治与地质环境利用

    Institute of Scientific and Technical Information of China (English)

    刘传正; 刘艳辉

    2012-01-01

    The situation of geo-hazards is severe in China. The status, trend and problem of geo-hazards prevention are discussed in this paper. On the one hand, in the view of geo-hazards prevention, the basis status of geo-hazards in China is discussed, and the prevention system of geo-hazards in China is studied. Then, with a typical debris flow, occurring in August 8, 2010, in Zhouqu County, Gansu Province, in the southwestern China, some problem and deficiency of geo-hazards prevention are discussed. On the other hand, in the view of geo-environment development, evaluation frame and system of regional geo-environment sustainable development are constructed, and geo-environment safety management is advanced. Finally, conclusions are as following: we should escape from the habitual thought of the single engineering geological evaluation or the single geo-hazards prevention. The protection of geo-environment and prevention of geo-hazards should be organic integrated to ease geo-hazards.%分析了中国地质灾害防治现状,概述了地质灾害防治体系,以甘肃舟曲“8.8”特大山洪泥石流灾害为例反思了地质灾害防治理念的不足.从地质环境可持续开发利用视角,构建了区域地质环境可持续利用评价框架和地质安全评价体系.基本结论是:应跳出单纯工程地质评价和地质灾害防治的惯性思维,将保护地质环境和防治地质灾害有机结合,树立持续利用地质环境的科学观,更有效地达到减轻地质灾害的目的.

  7. The principle of the positioning system based on communication satellites

    Institute of Scientific and Technical Information of China (English)

    AI GuoXiang; SHI HuLi; WU HaiTao; LI ZhiGang; GUO Ji

    2009-01-01

    It is a long dream to realize the communication and navigation functionality in a satellite system in the world.This paper introduces how to establish the system,a positioning system based on communication satellites called Chinese Area Positioning System (CAPS).Instead of the typical navigation satelIites,the communication satellites are configured firstly to transfer navigation signals from ground stations,and can be used to obtain service of the positioning,velocity and time,and to achieve the function of navigation and positioning.Some key technique issues should be first solved; they include the accuracy position determination and orbit prediction of the communication satellites,the measuring and calculation of transfer time of the signals,the carrier frequency drift in communication satellite ignal transfer,how to improve the geometrical configuration of the constellation in the system,and the integration of navigation & communication.Several innovative methods are developed to make the new system have full functions of navigation and communication.Based on the development of crucial techniques and methods,the CAPS demonstration system has been designed and developed.Four communication satellites in the geosynchronous orbit (GEO) located at 87.5°E,110.5°E,134°E,142°E and barometric altimetry are used in the CAPS system.The GEO satellites located at 134°E and 142°E re decommissioned GEO (DGEO) satellites.C-band is used as the navigation band.Dual frequency at C1=4143.15 MHz and C2=3826.02 MHz as well as dual codes with standard code (CA code and precision code (P code)) are adopted.The ground segment consists of five ground stations; the master station is in Lintong,Xi'an.The ground stations take a lot of responsibilities,including monitor and management of the operation of all system components,determination of the satellite position and prediction of the satellite orbit,accomplishment of the virtual atomic clock measurement,transmission and receiving

  8. Moscow State University near-Earth radiation monitoring satellite system: current status and development

    Science.gov (United States)

    Panasyuk, Mikhail

    2016-07-01

    Radiation measurements using instruments have been designed and manufacturing in the Skobeltsyn Institute of Nuclear Physics of Lomonosov Moscow State University and installed onboard different satellites,i.e. LEO -"Meteor", ISS, GPS - GLONASS, GEO - "Electro" are presented as a basis of radiation monitoring system for control of radiation condition with a goal for to decrease radiation risk of spacecraft's damage on different orbits. Development of this system including radiation measurements onboard "Lomonosov"(LEO) satellite will be presented as well together with future project of multispacecraft LEO system for radiation monitoring.

  9. Precise orbit determination for quad-constellation satellites at Wuhan University: strategy, result validation, and comparison

    Science.gov (United States)

    Guo, Jing; Xu, Xiaolong; Zhao, Qile; Liu, Jingnan

    2016-02-01

    This contribution summarizes the strategy used by Wuhan University (WHU) to determine precise orbit and clock products for Multi-GNSS Experiment (MGEX) of the International GNSS Service (IGS). In particular, the satellite attitude, phase center corrections, solar radiation pressure model developed and used for BDS satellites are addressed. In addition, this contribution analyzes the orbit and clock quality of the quad-constellation products from MGEX Analysis Centers (ACs) for a common time period of 1 year (2014). With IGS final GPS and GLONASS products as the reference, Multi-GNSS products of WHU (indicated by WUM) show the best agreement among these products from all MGEX ACs in both accuracy and stability. 3D Day Boundary Discontinuities (DBDs) range from 8 to 27 cm for Galileo-IOV satellites among all ACs' products, whereas WUM ones are the largest (about 26.2 cm). Among three types of BDS satellites, MEOs show the smallest DBDs from 10 to 27 cm, whereas the DBDs for all ACs products are at decimeter to meter level for GEOs and one to three decimeter for IGSOs, respectively. As to the satellite laser ranging (SLR) validation for Galileo-IOV satellites, the accuracy evaluated by SLR residuals is at the one decimeter level with the well-known systematic bias of about -5 cm for all ACs. For BDS satellites, the accuracy could reach decimeter level, one decimeter level, and centimeter level for GEOs, IGSOs, and MEOs, respectively. However, there is a noticeable bias in GEO SLR residuals. In addition, systematic errors dependent on orbit angle related to mismodeled solar radiation pressure (SRP) are present for BDS GEOs and IGSOs. The results of Multi-GNSS combined kinematic PPP demonstrate that the best accuracy of position and fastest convergence speed have been achieved using WUM products, particularly in the Up direction. Furthermore, the accuracy of static BDS only PPP degrades when the BDS IGSO and MEO satellites switches to orbit-normal orientation

  10. Refinements in the Combined Adjustment of Satellite Altimetry and Gravity Anomaly Data

    Science.gov (United States)

    1977-07-12

    of the areas covered by the GEOS-3 satellite when compared with the earlier reported results of the AFGL computer program SARRA ^(Short Arc Reduc...in the partial derivatives may be illustrated as follows. A small set of satellite altimetry data was adjusted by the AFGL program SARRA (Short Arc...1 l+2^(a/rf 2^(C cos mX + S sin mX)P ( sine ) n^2v m=0 nm nm nm i + h u>2r0r 3 co326/(kM) , (4.1) which yields dr (r0/r oo n )^n(a

  11. Big Data, Small Data: Accessing and Manipulating Geoscience Data Ranging From Repositories to Student-Collected Data Sets Using GeoMapApp

    Science.gov (United States)

    Goodwillie, A. M.

    2015-12-01

    international geological maps, and satellite imagery. Student-generated data sets can be imported in Excel, ASCII, shapefile, and gridded format. Base maps can be saved for posters and publications. A wide range of undergraduate enquiry-driven education modules for GeoMapApp is already available at SERC.

  12. Internet access for everybody: The satellite solution

    Science.gov (United States)

    Wittig, Manfred

    2009-01-01

    The use of the Internet has been grown tremendously within the last decade to more than one billion subscribers. The other five billion people on Earth cannot enjoy the possibilities offered by the Internet. The digital divide is everywhere: in the developing as well as in the developed part of the world. In the developing countries basic communication needs (voice, IP access) need to be provided to a large population not living in cities. In the developed part of the world people residing outside the large cities, on the nice country side, have still difficulties to get broadband access. The reason being, that the investment to install the network infrastructure to this minority part of the population is a major part of the total investment for the network. The benefit for the telecom operators is marginal to get these customers on board. In this paper an analysis of the Internet and satellite development is being presented and based on these historical data a prediction of a possible evolution of satellite communications and broadband access is performed. One result is that the capacity of the GEO ring at the Ka-band alone would allow to provide to each individual on Earth in 2050 (assumed to be 10 billion people) a monthly capacity of about 1 Gbyte for a charge of 1$ per month.

  13. Estimates of geothermal reservoir fluid characteristics: GeoSys.Chem and WATCH

    OpenAIRE

    Ignacio Salvador Torres-Alvarado; Mahendra P. Verma; Kizito Opondo; David Nieva; Füsun Tut Haklidir; Edgar Santoyo; Rosa María Barragán; Víctor Arellano

    2012-01-01

    A comparative study of the reservoir fluid characteristics calculation of ten production wells of Los Azufres, Los Humeros and Cerro Prieto geothermal fields using two computer codes GeoChem (GeoSys.Chem) and WATCH is presented. GeoSys.Chem estimates the reservoir temperature and vapor fraction through quartz geothermometry and assuming enthalpy conservation, while the average temperature of quartz and Na/K geothermometers is employed in WATCH and vapor fraction is also calculated through ent...

  14. Update on the NASA GEOS-5 Aerosol Forecasting and Data Assimilation System

    Science.gov (United States)

    Colarco, Peter; da Silva, Arlindo; Aquila, Valentina; Bian, Huisheng; Buchard, Virginie; Castellanos, Patricia; Darmenov, Anton; Follette-Cook, Melanie; Govindaraju, Ravi; Keller, Christoph; hide

    2017-01-01

    GEOS-5 is the Goddard Earth Observing System model. GEOS-5 is maintained by the NASA Global Modeling and Assimilation Office. Core development is within GMAO,Goddard Atmospheric Chemistry and Dynamics Laboratory, and with external partners. Primary GEOS-5 functions: Earth system model for studying climate variability and change, provide research quality reanalyses for supporting NASA instrument teams and scientific community, provide near-real time forecasts of meteorology,aerosols, and other atmospheric constituents to support NASA airborne campaigns.

  15. Experimental Study on the Precise Orbit Determination of the BeiDou Navigation Satellite System

    Directory of Open Access Journals (Sweden)

    Jens Wickert

    2013-03-01

    Full Text Available The regional service of the Chinese BeiDou satellite navigation system is now in operation with a constellation including five Geostationary Earth Orbit satellites (GEO, five Inclined Geosynchronous Orbit (IGSO satellites and four Medium Earth Orbit (MEO satellites. Besides the standard positioning service with positioning accuracy of about 10 m, both precise relative positioning and precise point positioning are already demonstrated. As is well known, precise orbit and clock determination is essential in enhancing precise positioning services. To improve the satellite orbits of the BeiDou regional system, we concentrate on the impact of the tracking geometry and the involvement of MEOs, and on the effect of integer ambiguity resolution as well. About seven weeks of data collected at the BeiDou Experimental Test Service (BETS network is employed in this experimental study. Several tracking scenarios are defined, various processing schemata are designed and carried out; and then, the estimates are compared and analyzed in detail. The results show that GEO orbits, especially the along-track component, can be significantly improved by extending the tracking network in China along longitude direction, whereas IGSOs gain more improvement if the tracking network extends in latitude. The involvement of MEOs and ambiguity-fixing also make the orbits better.

  16. Ozone retrievals from MAGEAQ GEO TIR+VIS for air quality

    Science.gov (United States)

    Quesada-Ruiz, Samuel; Attié, Jean-Luc; Lahoz, William A.; Abida, Rachid; El-Amraoui, Laaziz; Ricaud, Philippe; Zbinden, Regina; Spurr, Robert; da Silva, Arlindo M.

    2016-04-01

    Nowadays, air quality monitoring is based on the use of ground-based stations (GBS) or satellite measurements. GBS provide accurate measurements of pollutant concentrations, especially in the planetary boundary layer (PBL), but usually the spatial coverage is sparse. Polar-orbiting satellites provide good spatial resolution but low temporal coverage -this is insufficient for tracking pollutants exhibiting a diurnal cycle (Lahoz et al., 2012). However, pollutant concentrations can be measured by instruments placed on board a geostationary satellite, which can provide sufficiently high temporal and spatial resolutions (e.g. Hache et al., 2014). In this work, we investigate the potentiality of a possible future geostationary instrument, MAGEAQ (Monitoring the Atmosphere from Geostationary orbit for European Air Quality), for retrieving ozone measurements over Europe. In particular, MAGEAQ can provide 1-hour temporal sampling at 10x10km pixel resolution for measurements in both visible (VIS) and thermal infrared (TIR) bands -thus, we will be able to measure during the day and at night. MAGEAQ synthetic radiance observations are obtained through radiative transfer (RT) simulations using the VLIDORT discrete ordinate RT model (Spurr, 2006) based on output from the GEOS-5 Nature Run (Gelaro et al., 2015) providing optical information, plus a suitable instrument model. Ozone is retrieved from these synthetic measurements using the optimal estimation inversion scheme of Levenberg-Marquardt. Finally, we examine an application of the air quality concept based on these ozone retrievals during the heatwave event of July 2006 over Europe. REFERENCES Gelaro, R., Putman, W. M., Pawson, S., Draper, C., Molod, A., Norris, P. M., Ott, L., Privé, N., Reale, O., Achuthavarier, D., Bosilovich, M., Buchard, V., Chao, W., Coy, L., Cullather, R., da Silva, A., Darmenov, A., Errico, R. M., Fuentes, M., Kim, M-J., Koster, R., McCarty, W., Nattala, J., Partyka, G., Schubert, S., Vernieres, G

  17. Comparison Between Four Detection Algorithms for GEO Objects

    Science.gov (United States)

    Yanagisawa, T.; Uetsuhara, M.; Banno, H.; Kurosaki, H.; Kinoshita, D.; Kitazawa, Y.; Hanada, T.

    2012-09-01

    Four detection algorithms for GEO objects are being developed under the collaboration between Kyushu University, IHI corporation and JAXA. Each algorithm is designed to process CCD images to detect GEO objects. First one is PC based stacking method which has been developed in JAXA since 2000. Numerous CCD images are used to detect faint GEO objects below the limiting magnitude of a single CCD image. Sub-images are cropped from many CCD image to fit the movement of the objects. A median image of all the sub-images is then created. Although this method has an ability to detect faint objects, it takes time to analyze. Second one is the line-identifying technique which also uses many CCD frames and finds any series of objects that are arrayed on a straight line from the first frame to the last frame. This can analyze data faster than the stacking method, but cannot detect faint objects as the stacking method. Third one is the robust stacking method developed by IHI corporation which uses average instead of median to reduce analysis time. This has same analysis speed as the line-identifying technique and better detection capabilities in terms of the darkness. Forth one is the FPGA based stacking method which uses binalized images and a new algorithm installed in a FPGA board which reduce analysis time about one thousandth. All four algorithms analyzed the same sets of data to evaluate their advantages and disadvantages. By comparing their analysis times and results, an optimal usage of these algorithms are considered.

  18. A Geo-Distributed System Architecture for Different Domains

    Science.gov (United States)

    Moßgraber, Jürgen; Middleton, Stuart; Tao, Ran

    2013-04-01

    The presentation will describe work on the system-of-systems (SoS) architecture that is being developed in the EU FP7 project TRIDEC on "Collaborative, Complex and Critical Decision-Support in Evolving Crises". In this project we deal with two use-cases: Natural Crisis Management (e.g. Tsunami Early Warning) and Industrial Subsurface Development (e.g. drilling for oil). These use-cases seem to be quite different at first sight but share a lot of similarities, like managing and looking up available sensors, extracting data from them and annotate it semantically, intelligently manage the data (big data problem), run mathematical analysis algorithms on the data and finally provide decision support on this basis. The main challenge was to create a generic architecture which fits both use-cases. The requirements to the architecture are manifold and the whole spectrum of a modern, geo-distributed and collaborative system comes into play. Obviously, one cannot expect to tackle these challenges adequately with a monolithic system or with a single technology. Therefore, a system architecture providing the blueprints to implement the system-of-systems approach has to combine multiple technologies and architectural styles. The most important architectural challenges we needed to address are 1. Build a scalable communication layer for a System-of-sytems 2. Build a resilient communication layer for a System-of-sytems 3. Efficiently publish large volumes of semantically rich sensor data 4. Scalable and high performance storage of large distributed datasets 5. Handling federated multi-domain heterogeneous data 6. Discovery of resources in a geo-distributed SoS 7. Coordination of work between geo-distributed systems The design decisions made for each of them will be presented. These developed concepts are also applicable to the requirements of the Future Internet (FI) and Internet of Things (IoT) which will provide services like smart grids, smart metering, logistics and

  19. Geo-registration of Unprofessional and Weakly-related Image and Precision Evaluation

    Directory of Open Access Journals (Sweden)

    LIU Yingzhen

    2015-09-01

    Full Text Available The 3D geo-spatial model built by unprofessional and weakly-related image is a significant source of geo-spatial information. The unprofessional and weakly-related image cannot be useful geo-spatial information until be geo-registered with accurate geo-spatial orientation and location. In this paper, we present an automatic geo-registration using the coordination acquired by real-time GPS module. We calculate 2D and 3D spatial transformation parameters based on the spatial similarity between the image location in the geo-spatial coordination system and in the 3D reconstruction coordination system. Because of the poor precision of GPS information and especially the unstability of elevation measurement, we use RANSAC algorithm to get rid of outliers. In the experiment, we compare the geo-registered image positions to their differential GPS coordinates. The errors of translation, rotation and scaling are evaluated quantitively and the causes of bad result are analyzed. The experiment demonstrates that this geo-registration method can get a precise result with enough images.

  20. Geo synthetic-reinforced Pavement systems; Sistemas de pavimentos reforzados con geosinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Zornberg, J. G.

    2014-02-01

    Geo synthetics have been used as reinforcement inclusions to improve pavement performance. while there are clear field evidence of the benefit of using geo synthetic reinforcements, the specific conditions or mechanisms that govern the reinforcement of pavements are, at best, unclear and have remained largely unmeasured. Significant research has been recently conducted with the objectives of: (i) determining the relevant properties of geo synthetics that contribute to the enhanced performance of pavement systems, (ii) developing appropriate analytical, laboratory and field methods capable of quantifying the pavement performance, and (iii) enabling the prediction of pavement performance as a function of the properties of the various types of geo synthetics. (Author)

  1. The Phobos Atlas and Geo-portal: geodesy and cartography approach for planetary exploration

    Science.gov (United States)

    Karachevtseva, Irina; Kozlova, Natalia; Kokhanov, Alexander; Oberst, Jürgen; Zubarev, Anatoliy; Nadezhdina, Irina; Patraty, Vyacheslav; Konopikhin, Anatoliy; Garov, Andrey

    New Phobos mapping. Methods of image processing and modern GIS technologies provide the opportunity for high quality planetary mapping. The new Phobos DTM and global orthomosaic have been used for developing a geodatabase (Karachevtseva et al., 2012) which provides data for various surface spatial analyses: statistics of crater density, as well as studies of gravity field, geomorphology, and photometry. As mapping is the best way to visualize results of research based on spatial context we created the Phobos atlas. The new Phobos atlas includes: control points network which were calculated during photogrammetry processing of SRC images (Zubarev et al., 2012) and fundamental body parameters as a reference basis for Phobos research as well as GIS analyses of surface objects and geomorphologic studies. According to the structure of the atlas we used various scales and projections based on different coordinate system, including three-axial ellipsoid which parameters (a=13.24 km, b=11.49 km, c=9.48 km) derived from new Phobos shape model (Nadezhdina and Zubarev, 2014). The new Phobos atlas includes about 30 thematic original maps that illustrate the surface of the small body based on Mars Express data (Oberst et al., 2008) and illustrates results of various studies of Phobos:, geomorphology parameters of craters (Basilevsky et al., 2014), morphometry studies (Koknanov et al., 2012), statistics of crater size-frequency distributions based on multi-fractal approach (Uchaev Dm. et al., 2012). Phobos Geo-portal. The spatial data products which used for preparing maps for the Phobos atlas are available at the planetary data storage with access via Geo-portal (http://cartsrv.mexlab.ru/geoportal/), based on modern spatial and web-based technologies (Karachevtseva et al., 2013). Now we are developing Geodesy and Cartography node which can integrate various types of information not only for Phobos data, but other planets and their satellites, and it can be used for geo

  2. 多重休假Geo/Geo/1排队的均衡混合门限策略∗%Equilibrium Mixed Threshold Strategies in the Geo/Geo/1 Queue with Multiple Vacations

    Institute of Scientific and Technical Information of China (English)

    马琰; 李继红; 刘维奇

    2013-01-01

    This paper studies the equilibrium mixed threshold strategies of customers in the Geo/Geo/1 queue under multiple vacation policy. Customers decide by themselves whether to join or to balk. A“reward-cost”structure is built and the expected net benefit function is made to reflect the desire of customers for service. Based on the theory of QBD processes, the station-ary system behavior is analyzed. By introducing several proper functions, the mixed threshold strategies are provided and proved to be equilibrium strategies. Finally, we present numerical experiments to demonstrate the sensitivity of the equilibrium mixed thresholds strategies with respect to the system parameters. The results provide useful reference information to managers on the pricing problem in queueing system.%  本文基于多重休假Geo/Geo/1离散时间排队,研究顾客的均衡混合门限策略。强调排队系统中的决策主体是顾客,突破了以往只注重研究服务机构单方面行为的局限。建立了“收入–支出”结构,利用预期净收益函数,量化顾客的决策意愿;根据拟生灭过程理论,对系统进行了稳态分析;进而构造适当的函数,给出了寻找均衡混合门限策略的具体方法,并给予了证明;最后通过数值实验讨论了均衡策略对系统各参数的敏感性。研究结果为管理者探讨排队系统中的定价问题提供了理论参考。

  3. GeoPower – Geothermische Potentiale im Norden

    DEFF Research Database (Denmark)

    Kirsch, Reinhard; Hese, Fabian; Offermann, Petra;

    Das INTERREG IVa Projekt GeoPower hatte zum Ziel, Planungsgrundlagen für die Nutzung hydrothermaler Energie für das nördliche Schleswig-Holstein und das südliche Jütland (Dänemark) zu schaffen. Projektpartner waren die Geologischen Dienste von Dänemark und Grönland (GEUS) und Schleswig Holstein (......-Instituts für Geowissenschaftliche Gemeinschaftsaufgaben (LIAG, Hannover) eingeflossen und werden auf der Homepage von GEUS verfügbar sein. Die Projektergebnisse sind auch in einer Projektbroschüre zusammengefasst, die vom LLUR bzw. von den Autoren kostenfrei bezogen werden kann....

  4. Geo energy research and development: technology transfer update

    Energy Technology Data Exchange (ETDEWEB)

    Traeger, R.K.; Dugan, V.L.

    1983-01-01

    Sandia Geo Energy Programs in geothermal, coal, oil and gas, and synfuel technologies have been effective in transferring research concepts to applications in private industry. This report updates the previous summary (SAND82-0211, March 1982) to include recent technology transfers and to reflect recent changes in philosophy on technology transfer. Over 40 items transferred to industry have been identified in the areas of Hardware, Risk Removal and Understanding. Successful transfer is due largely to personal interactions between Sandia engineers and the technical staffs of private industry.

  5. MOBILE GEO-LOCATION ALGORITHM BASED ON LS-SVM

    Institute of Scientific and Technical Information of China (English)

    Sun Guolin; Guo Wei

    2005-01-01

    Support Vector Machine (SVM) is a powerful methodology for solving problems in non-linear classification, function estimation and density estimation, which has also led to many other recent developments in kernel based methods in general. This paper presents a highaccuracy and fault-tolerant SVM for the mobile geo-location problem, which is an important component of pervasive computing. Simulation results show its basic location performance, and illustrate impacts of the number of training samples and training area on test location error.

  6. Modeling the geographical studies with GeoGebra-software

    Directory of Open Access Journals (Sweden)

    Ionica Soare

    2010-01-01

    Full Text Available The problem of mathematical modeling in geography is one of the most important strategies in order to establish the evolution and the prevision of geographical phenomena. Models must have a simplified structure, to reflect essential components and must be selective, structured, and suggestive and approximate the reality. Models could be static or dynamic, developed in a theoretical, symbolic, conceptual or mental way, mathematically modeled. The present paper is focused on the virtual model which uses GeoGebra software, free and available at www.geogebra.org, in order to establish new methods of geographical analysis in a dynamic, didactic way.

  7. Modeling the geographical studies with GeoGebra-software

    CERN Document Server

    Soare, Ionica

    2012-01-01

    The problem of mathematical modeling in geography is one of the most important strategies in order to establish the evolution and the prevision of geographical phenomena. Models must have a simplified structure, to reflect essential components and must be selective, structured, and suggestive and approximate the reality. Models could be static or dynamic, developed in a theoretical, symbolic, conceptual or mental way, mathematically modeled. The present paper is focused on the virtual model which uses GeoGebra software, free and available at www.geogebra.org, in order to establish new methods of geographical analysis in a dynamic, didactic way.

  8. Towards Geo-spatial Hypermedia: Concepts and Prototype Implementation

    DEFF Research Database (Denmark)

    Grønbæk, Kaj; Vestergaard, Peter Posselt; Ørbæk, Peter

    2002-01-01

    This paper combines spatial hypermedia with techniques from Geographical Information Systems and location based services. We describe the Topos 3D Spatial Hypermedia system and how it has been developed to support geo-spatial hypermedia coupling hypermedia information to model representations...... of real world buildings and landscapes. The prototype experiments are primarily aimed at supporting architects and landscape architects in their work on site. Here it is useful to be able to superimpose and add different layers of information to, e.g. a landscape depending on the task being worked on. We...

  9. Improving Scientific Research for the GEO Geohazard Supersites through a Virtual Research Environment

    Science.gov (United States)

    Salvi, S.; Trasatti, E.; Rubbia, G.; Romaniello, V.; Spinetti, C.; Corradini, S.; Merucci, L.

    2016-12-01

    The EU's H2020 EVER-EST Project is dedicated to the realization of a Virtual Research Environment (VRE) for Earth Science researchers, during 2015-2018. EVER-EST implements state-of-the-art technologies in the area of Earth Science data catalogues, data access/processing and long-term data preservation together with models, techniques and tools for the computational methods, such as scientific workflows. The VRE is designed with the aim of providing the Earth Science user community with an innovative virtual environment to enhance their ability to interoperate and share knowledge and experience, exploiting also the Research Object concept. The GEO Geohazard Supersites is one of the four Research Communities chosen to validate the e-infrastructure. EVER-EST will help the exploitation of the full potential of the GEO Geohazard Supersite and Natural Laboratories (GSNL) initiative demonstrating the use case in the Permanent Supersites of Mt Etna, Campi Flegrei-Vesuvius, and Icelandic volcanoes. Besides providing tools for active volcanoes monitoring and studies, we intend to demonstrate how a more organized and collaborative research environment, such as a VRE, can improve the quality of the scientific research on the Geohazard Supersites, addressing at the same time the problem of the slow uptake of scientific research findings in Disaster Risk Management. Presently, the full exploitation of the in situ and satellite data made available for each Supersite is delayed by the difficult access (especially for researchers in developing countries) to intensive processing and modeling capabilities. EVER-EST is designed to provide these means and also a friendly virtual environment for the easy transfer of scientific knowledge as soon as it is acquired, promoting collaboration among researchers located in distant regions of the world. A further benefit will be to increase the societal impact of the scientific advancements obtained in the Supersites, allowing a more uniform

  10. Performance of McRAS-AC in the GEOS-5 AGCM: aerosol-cloud-microphysics, precipitation, cloud radiative effects, and circulation

    Directory of Open Access Journals (Sweden)

    Y. C. Sud

    2013-01-01

    Full Text Available A revised version of the Microphysics of clouds with Relaxed Arakawa-Schubert and Aerosol-Cloud interaction scheme (McRAS-AC including, among others, a new ice nucleation parameterization, is implemented in the GEOS-5 AGCM. Various fields from a 10-yr-long integration of the AGCM with McRAS-AC are compared with their counterparts from an integration of the baseline GEOS-5 AGCM, as well as satellite observations. Generally McRAS-AC simulations have smaller biases in cloud fields and cloud radiative effects over most of the regions of the Earth than the baseline GEOS-5 AGCM. Two systematic biases are identified in the McRAS-AC runs: one is underestimation of cloud particle numbers around 40° S–60° S, and one is overestimate of cloud water path during the Northern Hemisphere summer over the Gulf Stream and North Pacific. Sensitivity tests show that these biases potentially originate from biases in the aerosol input. The first bias is largely eliminated in a test run using 50% smaller radius of sea-salt aerosol particles, while the second bias is substantially reduced when interactive aerosol chemistry is turned on. The main weakness of McRAS-AC is the dearth of low-level marine stratus clouds, a probable outcome of lack of explicit dry-convection in the cloud scheme. Nevertheless, McRAS-AC largely simulates realistic clouds and their optical properties that can be improved further with better aerosol input. An assessment using the COSP simulator in a 1-yr integration provides additional perspectives for understanding cloud optical property differences between the baseline and McRAS-AC simulations and biases against satellite data. Overall, McRAS-AC physically couples aerosols, the microphysics and macrophysics of clouds, and their radiative effects and thereby has better potential to be a valuable tool for climate modeling research.

  11. Inter-satellite links: A versatile tool for geodesy and planetary and interplanetary navigation

    Science.gov (United States)

    Schlicht, Anja; Hugentobler, Urs; Hauk, Markus; Murböck, Michael; Pail, Roland

    2016-07-01

    With the use of low-low satellite-to-satellite tracking gravity field recovery made a big step forward. Based on this technique the Gravity Recovery And Climate Experiment (GRACE) mission delivers monthly gravity field with high precision, allowing to measure effects in Earth water storage basins and variations in ice mass in Greenland and Antarctica from space. GRACE is using a Ka-band inter-satellite ranging technique, GRACE Follow-On will in addition test optical ranging. In fundamental physics high-precision optical inter-satellite tracking will be used to detect gravitational waves in space, as a first step LISA Pathfinder was launched recently. Inter-satellite links are not only used for ranging, also data transfer in space is based on such links. ESA's European Data Relay System will be established in up-coming years to collect data from the low orbiting Sentinel satellites and transfer the high data rate to ground. The same link may be used for ranging, data transfer and time transfer, a functionality that is discussed for next generation Galileo satellites. But to exploit this synergy a common concept for all three tasks has to be developed. In this paper we show that with inter-satellite ranging techniques with µm accuracy the limited accuracy of GNSS based orbit determination of low Earth orbiters (LEO), which is due to the limitations of one-way microwave tracking (unsynchronized clocks, phase center variations and offsets of the sending and receiving antennas) can be overcome. In the ESA study GETRIS the following question is answered: How can a highly accurate and precise GEO-based two-way ranging method support GNSS tracking? The reduction of systematic errors in LEO precise orbit determination (POD) by exploiting the synergy between ranging, data- and time-transfer is assessed in a concept consisting of precise two-way GEO-LEO tracking (as used for data transfer) and an ultra-stable oscillator on-board of the geostationary satellite (GEO

  12. Mobile satellite communications handbook

    CERN Document Server

    Cochetti, Roger

    2014-01-01

    With a Preface by noted satellite scientist Dr. Ahmad Ghais, the Second Edition reflects the expanded user base for this technology by updating information on historic, current, and planned commercial and military satellite systems and by expanding sections that explain the technology for non-technical professionals.   The book begins with an introduction to satellite communications and goes on to provide an overview of the technologies involved in mobile satellite communications, providing basic introductions to RF Issues, power Issues, link issues and system issues. It describes

  13. Satellite communication antenna technology

    Science.gov (United States)

    Mittra, R. (Editor); Imbriale, W. A. (Editor); Maanders, E. J. (Editor)

    1983-01-01

    A general overview of current technology in the field of communication satellite antennas is presented. Among the topics discussed are: the design of multiple beam systems; frequency reuse; and polarization control of antenna measurements. Consideration is also given to: contour beam synthesis; dual shaped reflector synthesis; beam shaping; and offset reflector design. The applications of the above technologies to present and future generations of communications satellites is considered, with emphasis given to such systems as: the Intelsats; the Defense Satellite Communications System, (DSCS-III); Satellite Business System (SBS), and Comstar.

  14. Methods of satellite oceanography

    Science.gov (United States)

    Stewart, R. H.

    1985-01-01

    The theoretical basis for remote sensing measurements of climate and ocean dynamics is examined. Consideration is given to: the absorption of electromagnetic radiation in the atmosphere; scattering in the atmosphere; and satellite observations using visible light. Consideration is also given to: the theory of radio scatter from the sea; scatter of centimeter waves from the sea; and the theory of operation of synthetic aperture radars. Additional topics include: the coordinate systems of satellite orbits for oceanographic remote sensing applications; the operating features of the major U.S. satellite systems for viewing the ocean; and satellite altimetry.

  15. Geo-Studio在黄土边坡中的应用%The application of Geo-Studio in loess slope

    Institute of Scientific and Technical Information of China (English)

    涂杰楠; 李剑

    2007-01-01

    简述了GLE法的理论基础,针对某黄土边坡用SLOPE/W程序建立了边坡的计算模型,采用GLE法进行稳定性分析,得出安全系数,并通过图表对条块作用力边坡的变化规律做出分析,结果表明Geo-Studio在实际应用中是有工程意义的.

  16. Navigation and geo-tracking system of UAV EO payload

    Science.gov (United States)

    Chen, Ying; Zhen, Kang; Xue, Yuanyuan; Zhang, Xiajiang; Li, Yingjuan; Tang, Chao

    2016-01-01

    A multi-function system based on inertial measurement unit (IMU) is introduced, which can fulfill navigation, attitude measurement of LOS in payload, platform stabilization and tracking control. The IMU is integrated with electro-optical sensors and a laser range finder on gimbals, which performs attitude calculation and navigation by constructing navigation coordinates in a mathematic platform, and the platform navigation information is obtained by transformation matrix between platform and gimbal coordinates. The platform comprising of gyros, electro-optical sensors and servo mechanism is capable of stabilizing line of sight and could be used to geo-tracking in the relevant field of view (FOV).The system can determine geography coordinates of the host platform and target only with navigation information and laser ranging data. The geo-tracking system always locked the target image at the center of FOV by calculating spatial geometry and adjusting LOS attitude. This tracking is different from TV tracking and geographical reference image tracking, which may be influenced by fog and obscurant. When the UAV is flying over urban or mountain areas for rescue missions, it can avoid the loss of targets due to strong maneuver or LOS obscuration, and reduce the operation load and improve rescue efficiency.

  17. The Protection of Cultural Heritage Sites from Geo-Hazards

    Science.gov (United States)

    Themistocleous, Kyriacos; Agapiou, Athos; Cuca, Branka; Lysandrou, Vasiliki; Tzouvaras, Marios; Michaelides, Silas; Hadjimitsis, Diofantos; Margottini, Claudio; Cigna, Francesca; Crosta, Giovanni; Fernandez, Jose

    2016-04-01

    Cultural heritage sites are continuously impacted by several environmental and anthropogenic factors, including climate change, precipitation, natural hazards, wars, etc. However, there is limited data available regarding the effects of geo-hazards on cultural heritage sites. This paper presents the methodology of the PROTHEGO project, which uses radar interferometry to monitor surface deformation with mm precision to analyze the impact of geo-hazards in cultural heritage sites in Europe. PROTHEGO will provide a new, low-cost methodological approach for the safe management of cultural heritage monuments and sites located in Europe. The project will apply InSAR techniques to monitor monuments and sites that are potentially unstable due to landslides, sinkholes, settlement, subsidence, active tectonics as well as structural deformation, all of which can be effected of climate change and human interaction. The research methodology will be focused on long-term low-impact monitoring systems as well as indirect analysis of environmental contexts to investigate changes and decay of structure, material and landscape. The methodology will be applied to more than 450 sites on the UNESCO World Heritage List in geographical Europe. One of the case study selected is located in Cyprus at Choirokoitia, which is a UNESCO World Heritage site. The outcomes of PROTHEGO will support correct planning and rebalancing the contrast between endogenous (structural and materials decay, the societal development, the anthropogenic pressure) and surrounding exogenous forces (natural hazards acting on the heritage) which affecting the European cultural heritage.

  18. Connecting Representations and Mathematical Ideas with GeoGebra

    Directory of Open Access Journals (Sweden)

    İbrahim Bayazit

    2010-05-01

    Full Text Available Representations facilitate acquisition of mathematical notions and provide help to the learners in their thinking. A meaningful understanding of mathematical concepts can be attained when a variety of representations are developed and the functioning relationships are established among them. Traditional teaching approaches dominated by the use of chalk and board appear to be not so productive to help students establish connections between the representations. Nevertheless, the availability of instructional technology has enabled teachers to highlight interrelations between the representations of mathematical concepts so that their students could develop a much better understanding of these notions. In this chapter, we try illustrate opportunities that a recently developed computer program GeoGebra offers in teaching and learning mathematics. The scope of this chapter is limited to the discussion of three aspects of GeoGebra in teaching algebra. These include: supporting operational and structural conceptions of the functions, illustrating factual knowledge associated with the equation systems, and constructing graphical models for the solution of algebra problems.

  19. Maps and virtual geo-presentations in contemporary instruction

    Directory of Open Access Journals (Sweden)

    Vemić Mirčeta

    2009-01-01

    Full Text Available This paper analyses the basic questions regarding cartographic visualization in instruction, where traditional maps, atlases and globes were considered only as simple visual aids belonging together with original objects and pictures, while cartographers elevated them to a higher cognitive level, labelling them 'eye of geography', 'sediment of the entire knowledge', 'philosopher's stone', or the very 'foundation' of geography. Maps were always required to be correct, comprehensive, clear, understandable, legible, to have nice appearance and format, which suggests the 'invariability' of maps, although the technique and technology change. Contemporary computer technology changed the cartographic picture in the form of virtual geo-presentations and geographic information systems. Through mutual comparison with traditional maps it is easier to discern all the aspects of their application in contemporary instruction. This paper particularly analyses epistemological, semiotic, methodological and didactic-methodical aspects of maps and virtual geo-presentations, with the emphasis on their perceptive possibilities. By introducing the teacher with the aforementioned aspects, they are demystified, didactic process is elevated and a wider application in contemporary instruction opens up, either with respect to content presentation or application of direct mapping through exercises, workshops, seminar or graduation papers. Knowledge adopted in this way influences creation of a higher level of creative thinking, that is, visual thinking.

  20. GeoHealth: A Transdisciplinary Science Comes of Age

    Science.gov (United States)

    McEntee, C.

    2016-12-01

    GeoHealth is a transdisciplinary research discipline that connects Earth and environmental sciences with ecosystem and human health sciences. Geohealth research advances both basic and solutions focused research to address global societal challenges in ecosystem and human health. Some of the areas being addressed by geohealth include toxic substances in water, atmosphere, and soil and their effect on human health and environmental health. Geohealth research has been underway for several decades; several examples of recent prominent research findings include identifying complex exposures to dust in the aftermath of the 9/11 attack on the World Trade Center and a better understanding of toxic exposures from the Gulf oil spill and their health effects on humans and other species both on land and in water. Over the past decade, GeoHealth research output has grown significantly as evidenced by research output in both the volume of meeting abstracts and journal articles and by significant funding commitments by governmental funding agencies around the world. This presentation will provide an overview of scientific research areas encompassed in geohealth, data that demonstrate a nearly 50% increase in geohealth research output between 2010 and 2015, the double digit growth of geohealth research output in AGU meetings and journals, and which countries are currently leading in geohealth research output. An overview of government funding sources for geohealth research both within and outside the United States along with new AGU geohealth initiatives will also be presented.