Airborne Gravity: NGS' Gravity Data for EN06 (2016)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Maine, Canada, and the Atlantic Ocean collected in 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the...

Airborne Gravity: NGS' Gravity Data for AN02 (2010)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for ES01 (2013)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Florida, the Bahamas, and the Atlantic Ocean collected in 2013 over 1 survey. This data set is part of the Gravity for the Re-definition of...

Airborne Gravity: NGS' Gravity Data for CS08 (2015)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for CS08 collected in 2006 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum (GRAV-D)...

Airborne Gravity: NGS' Gravity Data for ES02 (2013)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Florida and the Gulf of Mexico collected in 2013 over 1 survey. This data set is part of the Gravity for the Re-definition of the American...

Airborne Gravity: NGS' Gravity Data for CN02 (2013 & 2014)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Nebraska collected in 2013 & 2014 over 3 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...

Airborne Gravity: NGS' Gravity Data for CS02 (2008-2009)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Louisana and Mississippi collected in 2008-2009 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American...

Airborne Gravity: NGS' Gravity Data for EN07 (2012-2013)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Maine and Canada collected in 2012 and 2013 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American...

Airborne Gravity: NGS' Gravity Data for AS03 (2010-2012)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 and 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

Airborne Gravity: NGS' Gravity Data for ES05 (2015-2016)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Florida and the Atlantic Ocean collected in two surveys, FL15-1 and FL15-2. This data set is part of the Gravity for the Re-definition of...

Airborne Gravity: NGS' Gravity Data for AS04 (2015-2016)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2015 and 2016 over 2 surveys, AK15 and AK16. This data set is part of the Gravity for the Re-definition of the American...

Airborne Gravity: NGS' Gravity Data for CS07 (2014 & 2016)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Texas collected in 2014 & 2016 over 3 surveys,TX14-2, TX16-1 and TX16-2. This data set is part of the Gravity for the Re-definition of...

Airborne Gravity: NGS' Gravity Data for ES03 (2013)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Maryland, Pennsylvania, New Jersey, West Virginia, Virginia, Delaware, and the Atlantic Ocean collected in 2013 over 1 survey. This data...

Merging of airborne gravity and gravity derived from satellite altimetry: Test cases along the coast of greenland

DEFF Research Database (Denmark)

Olesen, Arne Vestergaard; Andersen, Ole Baltazar; Tscherning, C.C.

2002-01-01

for the use of gravity data especially, when computing geoid models in coastal regions. The presence of reliable marine gravity data for independent control offers an opportunity to study procedures for the merging of airborne and satellite data around Greenland. Two different merging techniques, both based......The National Survey and Cadastre - Denmark (KMS) has for several years produced gravity anomaly maps over the oceans derived from satellite altimetry. During the last four years, KMS has also conducted airborne gravity surveys along the coast of Greenland dedicated to complement the existing...... onshore gravity coverage and fill in new data in the very-near coastal area, where altimetry data may contain gross errors. The airborne surveys extend from the coastline to approximately 100 km offshore, along 6000 km of coastline. An adequate merging of these different data sources is important...

Airborne Gravity: NGS' Gravity Data for EN09 (2016)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Massachusetts, Connecticut, Rhode Island, New Hampshire, New York, and the Atlantic Ocean collected in 2012 over 1 survey. This data set is...

Airborne Gravity: NGS' Gravity Data for EN10 (2013)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Pennsylvania, New Jersey, Connecticut and the Atlantic Ocean collected in 2013 over 1 survey. This data set is part of the...

Airborne Gravity: NGS' Gravity Data for MS02 (2016)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data over southern Arizona and New Mexico overlapping into Mexico collected in 2016 over 2 surveys, AZ16-1 and AZ16-2. This data set is part of the...

Airborne Gravity: NGS' Gravity Data for ES04 (2013-2014)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for North Carolina, South Carolina, Virginia, and the Atlantic Ocean collected in 2013 and 2014 over two surveys. This data set is part of the...

Airborne Gravity: NGS' Gravity Data for EN02 (2011-2012)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Pennsylvania, Ohio, Michigan, Canada and Lake Erie collected in 2011 and 2012 over 3 surveys. This data set is part of the...

Airborne Gravimetry Survey for the Marine Area of the United Arab Emirates

DEFF Research Database (Denmark)

Forsberg, René; Olesen, Arne Vestergaard; Alshamsi, Adel

2012-01-01

The Military Survey Department (MSD) of the United Arab Emirates (UAE) undertook an airborne gravity survey project for the marine area of the country in 2009, especially to strengthen the marine and coastal geoid in the near-shore regions. For the airborne gravity survey, 5 km spacing coast...... flight speed of 170 knots and a typical flight elevation of 900-1500 m, depending on weather conditions and topography. Gravity was measured with a ZLS-modified LaCoste and Romberg gravimeter (S-99), augmented with a Honeywell strap-down inertial navigation system unit. The estimated accuracy...

Using an Optionally Piloted Aircraft for Airborne Gravity Observations with the NOAA GRAV-D Project

Science.gov (United States)

Youngman, M.; Johnson, J. A.; van Westrum, D.; Damiani, T.

2017-12-01

The U.S. National Geodetic Survey's (NGS) Gravity for the Redefintion of the American Vertical Datum (GRAV-D) project is collecting airborne gravity data to support a 1 cm geoid. Started in 2008, this project will collect airborne gravity data over the entire U.S. and territories by 2022. As of June 30, 2017, the project was almost 62% complete. With recent technological developments, NGS has been exploring using unmanned aircraft for airborne gravity measurements. This presentation will focus on results from two surveys over the U.S. Appalachian and Rocky Mountains using the Aurora Centaur Optionally Piloted Aircraft and the Micro-g Lacoste Turnkey Airborne Gravimeter System 7 (TAGS7). Collecting high quality data as well as dealing with remote locations has been a challenge for the GRAV-D project and the field of airborne gravity in general. Unmanned aircraft could potentially improve data quality, handle hard to reach locations, and reduce pilot fatigue. The optionally piloted Centaur aircraft is an attractive option because it is not restricted in U.S. airspace and delivers high quality gravity data. Specifically, the Centaur meets U.S. Federal Aviation Administration regulations for Unmanned Aircraft Systems (UAS) by using a safety pilot on board to maintain line of sight and the ability to take control in the event of an emergency. Even though this is a sizeable UAS, most traditional gravimeters are too large and heavy for the platform. With a smaller and lighter design, the TAGS7 was used for its ability to conform to the aircraft's size restrictions, with the added benefit of upgraded performance capabilities. Two surveys were performed with this aircraft and gravimeter, one in April and one in August to September of 2017. Initial results indicate that the high-gain, fast response of the Centaur autopilot (optimized for flights without passengers), coupled with the full-force feedback sensor of the TAGS7, provides superior performance in all conditions, and

Moving base Gravity Gradiometer Survey System (GGSS) program

Science.gov (United States)

Pfohl, Louis; Rusnak, Walter; Jircitano, Albert; Grierson, Andrew

1988-04-01

The GGSS program began in early 1983 with the objective of delivering a landmobile and airborne system capable of fast, accurate, and economical gravity gradient surveys of large areas anywhere in the world. The objective included the development and use of post-mission data reduction software to process the survey data into solutions for the gravity disturbance vector components (north, east and vertical). This document describes the GGSS equipment hardware and software, integration and lab test procedures and results, and airborne and land survey procedures and results. Included are discussions on test strategies, post-mission data reduction algorithms, and the data reduction processing experience. Perspectives and conclusions are drawn from the results.

The Effects of Lever Arm (Instrument Offset) Error on GRAV-D Airborne Gravity Data

Science.gov (United States)

Johnson, J. A.; Youngman, M.; Damiani, T.

2017-12-01

High quality airborne gravity collection with a 2-axis, stabilized platform gravity instrument, such as with a Micro-g LaCoste Turnkey Airborne Gravity System (TAGS), is dependent on the aircraft's ability to maintain "straight and level" flight. However, during flight there is constant rotation about the aircraft's center of gravity. Standard practice is to install the scientific equipment close to the aircraft's estimated center of gravity to minimize the relative rotations with aircraft motion. However, there remain small offsets between the instruments. These distance offsets, the lever arm, are used to define the rigid-body, spatial relationship between the IMU, GPS antenna, and airborne gravimeter within the aircraft body frame. The Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project, which is collecting airborne gravity data across the U.S., uses a commercial software package for coupled IMU-GNSS aircraft positioning. This software incorporates a lever arm correction to calculate a precise position for the airborne gravimeter. The positioning software must do a coordinate transformation to relate each epoch of the coupled GNSS-IMU derived position to the position of the gravimeter within the constantly-rotating aircraft. This transformation requires three inputs: accurate IMU-measured aircraft rotations, GNSS positions, and lever arm distances between instruments. Previous studies show that correcting for the lever arm distances improves gravity results, but no sensitivity tests have been done to investigate how error in the lever arm distances affects the final airborne gravity products. This research investigates the effects of lever arm measurement error on airborne gravity data. GRAV-D lever arms are nominally measured to the cm-level using surveying equipment. "Truth" data sets will be created by processing GRAV-D flight lines with both relatively small lever arms and large lever arms. Then negative and positive incremental

Strapdown Airborne Gravimetry Using a Combination of Commercial Software and Stable-Platform Gravity Estimates

DEFF Research Database (Denmark)

Jensen, Tim E.; Nielsen, J. Emil; Olesen, Arne V.

2017-01-01

into the long-wavelengths of the gravity estimates. This has made the stable-platform approach the preferred method for geodetic applications. In the summer of 2016, during a large airborne survey in Malaysia, a SIMU system was flown alongside a traditional LaCoste&Romberg (LCR) gravimeter. The SIMU......For the past two decades, airborne gravimetry using a Strapdown Inertial Measurement Unit (SIMU) has been producing gravity estimates comparable to the traditional stable-platform single-axis gravimeters. The challenge has been to control the long term drift of the IMU sensors, propagating...

Marine Geoid Undulation Assessment Over South China Sea Using Global Geopotential Models and Airborne Gravity Data

Science.gov (United States)

Yazid, N. M.; Din, A. H. M.; Omar, K. M.; Som, Z. A. M.; Omar, A. H.; Yahaya, N. A. Z.; Tugi, A.

2016-09-01

Global geopotential models (GGMs) are vital in computing global geoid undulations heights. Based on the ellipsoidal height by Global Navigation Satellite System (GNSS) observations, the accurate orthometric height can be calculated by adding precise and accurate geoid undulations model information. However, GGMs also provide data from the satellite gravity missions such as GRACE, GOCE and CHAMP. Thus, this will assist to enhance the global geoid undulations data. A statistical assessment has been made between geoid undulations derived from 4 GGMs and the airborne gravity data provided by Department of Survey and Mapping Malaysia (DSMM). The goal of this study is the selection of the best possible GGM that best matches statistically with the geoid undulations of airborne gravity data under the Marine Geodetic Infrastructures in Malaysian Waters (MAGIC) Project over marine areas in Sabah. The correlation coefficients and the RMS value for the geoid undulations of GGM and airborne gravity data were computed. The correlation coefficients between EGM 2008 and airborne gravity data is 1 while RMS value is 0.1499.In this study, the RMS value of EGM 2008 is the lowest among the others. Regarding to the statistical analysis, it clearly represents that EGM 2008 is the best fit for marine geoid undulations throughout South China Sea.

Space-Wise approach for airborne gravity data modelling

Science.gov (United States)

Sampietro, D.; Capponi, M.; Mansi, A. H.; Gatti, A.; Marchetti, P.; Sansò, F.

2017-05-01

Regional gravity field modelling by means of remove-compute-restore procedure is nowadays widely applied in different contexts: it is the most used technique for regional gravimetric geoid determination, and it is also used in exploration geophysics to predict grids of gravity anomalies (Bouguer, free-air, isostatic, etc.), which are useful to understand and map geological structures in a specific region. Considering this last application, due to the required accuracy and resolution, airborne gravity observations are usually adopted. However, due to the relatively high acquisition velocity, presence of atmospheric turbulence, aircraft vibration, instrumental drift, etc., airborne data are usually contaminated by a very high observation error. For this reason, a proper procedure to filter the raw observations in both the low and high frequencies should be applied to recover valuable information. In this work, a software to filter and grid raw airborne observations is presented: the proposed solution consists in a combination of an along-track Wiener filter and a classical Least Squares Collocation technique. Basically, the proposed procedure is an adaptation to airborne gravimetry of the Space-Wise approach, developed by Politecnico di Milano to process data coming from the ESA satellite mission GOCE. Among the main differences with respect to the satellite application of this approach, there is the fact that, while in processing GOCE data the stochastic characteristics of the observation error can be considered a-priori well known, in airborne gravimetry, due to the complex environment in which the observations are acquired, these characteristics are unknown and should be retrieved from the dataset itself. The presented solution is suited for airborne data analysis in order to be able to quickly filter and grid gravity observations in an easy way. Some innovative theoretical aspects focusing in particular on the theoretical covariance modelling are presented too

The Effect of Pitch, Roll, and Yaw on Airborne Gravity Observations of the NOAA GRAV-D Project

Science.gov (United States)

Childers, V. A.; Kanney, J.; Youngman, M.

2017-12-01

Aircraft turbulence can wreak havoc on the gravity measurementby beam-style gravimeters. Prior studies have confirmed the correlation of poor quality airborne gravity data collection to amplified aircraft motion. Motion in the aircraft is the combined effect of the airframe design, the autopilot and its performance, and the weather/wind regime. NOAA's National Geodetic Survey has launched the Gravity for the Redefinition of the American Vertical Datum project (GRAV-D) to provide the foundation for a new national vertical datum by 2022. This project requires collecting airborne gravity data covering the entire country and its holdings. The motion of the aircraft employed in this project is of prime importance because we use a beam-style gravimeter mounted on a gyro-stabilized platform to align the sensor to a time-averaged local vertical. Aircraft turbulence will tend to drive the platform off-level, allowing horizontal forces to map into the vertical gravity measurement. Recently, the GRAV-D project has experimented with two new factors in airborne gravity data collection. The first aspect is the use of the Aurora optionally piloted Centaur aircraft. This aircraft can be flown either with or without a pilot, but the autopilot is specifically designed to be very accurate. Incorporated into the much smaller frame of this aircraft is a new gravimeter developed by Micro-g LaCoste, called the Turnkey Airborne Gravimeter System 7 (TAGS7). This smaller, lighter instrument also has a new design whereby the beam is held fixed in an electromagnetic force field. The result of this new configuration is notably improved data quality in wind conditions higher than can be tolerated by our current system. So, which caused the improvement, the aircraft motion or the new meter? This study will start to tease apart these two effects with recently collected survey data. Specifically, we will compare the motion profile of the Centaur aircraft with other aircraft in the GRAV-D portfolio

Airborne geoid determination

DEFF Research Database (Denmark)

Forsberg, René; Olesen, Arne Vestergaard; Bastos, L.

2000-01-01

Airborne geoid mapping techniques may provide the opportunity to improve the geoid over vast areas of the Earth, such as polar areas, tropical jungles and mountainous areas, and provide an accurate "seam-less" geoid model across most coastal regions. Determination of the geoid by airborne methods...... relies on the development of airborne gravimetry, which in turn is dependent on developments in kinematic GPS. Routine accuracy of airborne gravimetry are now at the 2 mGal level, which may translate into 5-10 cm geoid accuracy on regional scales. The error behaviour of airborne gravimetry is well......-suited for geoid determination, with high-frequency survey and downward continuation noise being offset by the low-pass gravity to geoid filtering operation. In the paper the basic principles of airborne geoid determination are outlined, and examples of results of recent airborne gravity and geoid surveys...

Modelling airborne gravity data by means of adapted Space-Wise approach

Science.gov (United States)

Sampietro, Daniele; Capponi, Martina; Hamdi Mansi, Ahmed; Gatti, Andrea

2017-04-01

Regional gravity field modelling by means of remove - restore procedure is nowadays widely applied to predict grids of gravity anomalies (Bouguer, free-air, isostatic, etc.) in gravimetric geoid determination as well as in exploration geophysics. Considering this last application, due to the required accuracy and resolution, airborne gravity observations are generally adopted. However due to the relatively high acquisition velocity, presence of atmospheric turbulence, aircraft vibration, instrumental drift, etc. airborne data are contaminated by a very high observation error. For this reason, a proper procedure to filter the raw observations both in the low and high frequency should be applied to recover valuable information. In this work, a procedure to predict a grid or a set of filtered along track gravity anomalies, by merging GGM and airborne dataset, is presented. The proposed algorithm, like the Space-Wise approach developed by Politecnico di Milano in the framework of GOCE data analysis, is based on a combination of along track Wiener filter and Least Squares Collocation adjustment and properly considers the different altitudes of the gravity observations. Among the main differences with respect to the satellite application of the Space-Wise approach there is the fact that, while in processing GOCE data the stochastic characteristics of the observation error can be considered a-priori well known, in airborne gravimetry, due to the complex environment in which the observations are acquired, these characteristics are unknown and should be retrieved from the dataset itself. Some innovative theoretical aspects focusing in particular on the theoretical covariance modelling are presented too. In the end, the goodness of the procedure is evaluated by means of a test on real data recovering the gravitational signal with a predicted accuracy of about 0.25 mGal.

Airborne Gravity Data Denoising Based on Empirical Mode Decomposition: A Case Study for SGA-WZ Greenland Test Data

DEFF Research Database (Denmark)

Zhao, Lei; Wu, Meiping; Forsberg, René

2015-01-01

Surveying the Earth's gravity field refers to an important domain of Geodesy, involving deep connections with Earth Sciences and Geo-information. Airborne gravimetry is an effective tool for collecting gravity data with mGal accuracy and a spatial resolution of several kilometers. The main obstacle......-WZ carried out in Greenland. Comparing to the solutions of using finite impulse response filter (FIR), the new results are improved by 40% and 10% of root mean square (RMS) of internal consistency and external accuracy, respectively....

Airborne gravity tests in the Italian area to improve the geoid model of Italy

DEFF Research Database (Denmark)

Barzaghi, R; Borghi, A; Keller, K

2009-01-01

Airborne gravimetry is an important method for measuring gravity over large unsurveyed areas. This technology has been widely applied in Canada, Antarctica and Greenland to map the gravity fields of these regions and in recent years, in the oil industry. In 2005, two tests in the Italian area were...... performed by ENI in cooperation with the Politecnico di Milano and the Danish National Space Center. To the knowledge of the authors, these were the first experiments of this kind in Italy and were performed over the Ionian coasts of Calabria and the Maiella Mountains. The Calabria test field......, the collocation method applied to compare and merge ground-based and airborne data proved to be efficient and reliable. The standard deviation of the discrepancies between airborne data and collocation upward continued gravity is, in both cases, less than 8 mgal. In the Maiella test, the gravity field obtained...

On the use of airborne gravimetry in gravity field modelling: Experiences from the AGMASCO project

DEFF Research Database (Denmark)

Bastos, L.; Cunha, S.; Forsberg, René

2000-01-01

of the vertical accelerations acting on the airborne platform from the natural gravity signal. With the advances in DGPS techniques new prospects arise for gravity field recovery which are of great importance for geodesy, geophysics oceanography and satellite navigation. Furthermore, airborne gravimetric...... and the methods validated. Recovery of the gravity values directly from measurements with the Lacoste & Romberg air/sea gravimeter and from measurements with the inertial sensors was analysed. The potential of these sensors to recover gravity and the experience gained within this project are reported here....

Far-zone contributions of airborne gravity anomalies' upward/downward continuation

Directory of Open Access Journals (Sweden)

Boyang Zhou

2016-11-01

Full Text Available Airborne gravimetry has become a vital technique in local gravity field approximation, and upward/downward continuation of gravity data is a key process of airborne gravimetry. In these procedures, the integral domain is divided into two parts, namely the near-zone and the far-zone. The far-zone contributions are approximated by the truncation coefficients and a global geo-potential model, and their values are controlled by several issues. This paper investigates the effects of flight height, the size of near-zone cap, and Remove-Compute-Restore (RCR technique upon far-zone contributions. Results show that at mountainous area the far-zone contributions can be ignored when EIGEN-6C of 360 degree is removed from the gravity data, together with a near-zone cap of 1° and a flight height less than 10 km, while at flat area EIGEN-6C of 180 degree is feasible.

Miniaturised Gravity Sensors for Remote Gravity Surveys.

Science.gov (United States)

Middlemiss, R. P.; Bramsiepe, S. G.; Hough, J.; Paul, D. J.; Rowan, S.; Samarelli, A.; Hammond, G.

2016-12-01

Gravimetry lets us see the world from a completely different perspective. The ability to measure tiny variations in gravitational acceleration (g), allows one to see not just the Earth's gravitational pull, but the influence of smaller objects. The more accurate the gravimeter, the smaller the objects one can see. Gravimetry has applications in many different fields: from tracking magma moving under volcanoes before eruptions; to locating hidden tunnels. The top commercial gravimeters weigh tens of kg and cost at least $100,000, limiting the situations in which they can be used. By contrast, smart phones use a MEMS (microelectromechanical system) accelerometer that can measure the orientation of the device. These are not nearly sensitive or stable enough to be used for the gravimetry but they are cheap, light-weight and mass-producible. At Glasgow University we have developed a MEMS device with both the stability and sensitivity for useful gravimetric measurements. This was demonstrated by a measurement of the Earth tides - the first time this has been achieved with a MEMS sensor. A gravimeter of this size opens up the possiblility for new gravity imaging modalities. Thousands of gravimeters could be networked over a survey site, storing data on an SD card or communicating wirelessly to a remote location. These devices could also be small enough to be carried by a UAVs: airborne gravity surveys could be carried out at low altitude by mulitple UAVs, or UAVs could be used to deliver ground based gravimeters to remote or inaccessible locations.

Airborne gravimetry for geoid and GOCE

DEFF Research Database (Denmark)

Forsberg, R.; Olesen, A. V.; Nielsen, E.

2014-01-01

DTU-Space has since 1996 carried out large area airborne surveys over both polar, tropical and temperate regions, especially for geoid determination and global geopotential models. Recently we have started flying two gravimeters (LCR and Chekan-AM) side by side for increased reliability and redun......DTU-Space has since 1996 carried out large area airborne surveys over both polar, tropical and temperate regions, especially for geoid determination and global geopotential models. Recently we have started flying two gravimeters (LCR and Chekan-AM) side by side for increased reliability...... in Antarctica and Tanzania based on DTU-Space aerogravity and GOCE. In both cases the airborne data validate GOCE to very high degrees, and confirms the synergy of airborne gravity and GOCE. For Antarctica, the deep interior Antarctic survey (continued in 2013 from a remote field camp), shows...... that it is possible efficiently to cover even the most remote regions on the planet with good aerogravity. With the recent termination of the GOCE mission, it is therefore timely to initiate a coordinated, preferably international, airborne gravity effort to cover the polar gap south of 83° S; such a survey can...

A comparison of stable platform and strapdown airborne gravity

DEFF Research Database (Denmark)

Glennie, C.L.; Schwarz, K.P.; Bruton, A.M.

2000-01-01

To date, operational airborne gravity results have been obtained using either a damped two-axis stable platform gravimeter system such as the LaCoste and Romberg (LCR) S-model marine gravimeter or a strapdown inertial navigation system (INS), showing comparable accuracies. In June 1998 three flight...

Airborne Gravity: NGS' Gravity Data for the US and Territories (2008-2022) - National Geospatial Data Asset (NGDA) Airborne Gravity (GRAV-D)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Gravity for the Re-definition of the American Vertical Datum (GRAV-D) is a project initiated by NOAA's National Geodetic Survey to collect and monitor gravity data...

Upward continuation of Dome-C airborne gravity and comparison with GOCE gradients at orbit altitude in east Antarctica

DEFF Research Database (Denmark)

Yildiz, Hasan; Forsberg, René; Tscherning, Carl Christian

2017-01-01

spherical harmonic models confirmed the quality of the airborne data and that they contain more high-frequency signal than the global models. First, the airborne gravity data were upward continued to GOCE altitude to predict gravity gradients in the local North-East-Up reference frame. In this step...

Geoid Model and Altitude at Mount Aconcagua Region (Argentina) from Airborne Gravity Survey

DEFF Research Database (Denmark)

Cristina Pacino, M.; Jaeger, Eric; Forsberg, René

2014-01-01

Aconcagua is part of the Southern Andes in the Argentine Province of Mendoza and it is the highest mountain in the Americas. The Aconcagua region is mostly inaccessible for land surveys. The existing gravity data are sparsely distributed, and mainly along the route currently used to climb the mou...

Effect of External Disturbing Gravity Field on Spacecraft Guidance and Surveying Line Layout for Marine Gravity Survey

Directory of Open Access Journals (Sweden)

HUANG Motao

2016-11-01

Full Text Available Centred on the support requirement of flying track control for a long range spacecraft, a detail research is made on the computation of external disturbing gravity field, the survey accuracy of gravity anomaly on the earth' surface and the program of surveying line layout for marine gravity survey. Firstly, the solution expression of navigation error for a long range spacecraft is analyzed and modified, and the influence of the earth's gravity field on flying track of spacecraft is evaluated. Then with a given limited quota of biased error of spacecraft drop point, the accuracy requirement for calculating the external disturbing gravity field is discussed and researched. Secondly, the data truncation error and the propagated data error are studied and estimated, and the quotas of survey resolution and computation accuracy for gravity anomaly on the earth' surface are determined. Finally, based on the above quotas, a corresponding program of surveying line layout for marine gravity survey is proposed. A numerical test has been made to prove the reasonableness and validity of the suggested program.

Airborne gravity field Measurements - status and developments

DEFF Research Database (Denmark)

Olesen, Arne Vestergaard; Forsberg, René

2016-01-01

English Abstract:DTU-Space has since 1996 carried out large area airborne surveys over both polar, tropical and temperate regions, especially for geoid determination and global geopotential models. Recently we have started flying two gravimeters (LCR and Chekan-AM or inertial navigation systems) ...

Geophex Airborne Unmanned Survey System

International Nuclear Information System (INIS)

Won, I.L.; Keiswetter, D.

1995-01-01

Ground-based surveys place personnel at risk due to the proximity of buried unexploded ordnance (UXO) items or by exposure to radioactive materials and hazardous chemicals. The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide stand-off capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected. The Geophex Airborne Unmanned Survey System (GAUSS) is designed to detect and locate small-scale anomalies at hazardous sites using magnetic and electromagnetic survey techniques. The system consists of a remotely-piloted, radio-controlled, model helicopter (RCH) with flight computer, light-weight geophysical sensors, an electronic positioning system, a data telemetry system, and a computer base-station. The report describes GAUSS and its test results

Geophex Airborne Unmanned Survey System

Energy Technology Data Exchange (ETDEWEB)

Won, I.L.; Keiswetter, D.

1995-12-31

Ground-based surveys place personnel at risk due to the proximity of buried unexploded ordnance (UXO) items or by exposure to radioactive materials and hazardous chemicals. The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide stand-off capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected. The Geophex Airborne Unmanned Survey System (GAUSS) is designed to detect and locate small-scale anomalies at hazardous sites using magnetic and electromagnetic survey techniques. The system consists of a remotely-piloted, radio-controlled, model helicopter (RCH) with flight computer, light-weight geophysical sensors, an electronic positioning system, a data telemetry system, and a computer base-station. The report describes GAUSS and its test results.

Integrated application of the database for airborne geophysical survey achievement information

International Nuclear Information System (INIS)

Ji Zengxian; Zhang Junwei

2006-01-01

The paper briefly introduces the database of information for airborne geophysical survey achievements. This database was developed on the platform of Microsoft Windows System with the technical methods of Visual C++ 6.0 and MapGIS. It is an information management system concerning airborne geophysical surveying achievements with perfect functions in graphic display, graphic cutting and output, query of data, printing of documents and reports, maintenance of database, etc. All information of airborne geophysical survey achievements in nuclear industry from 1972 to 2003 was embedded in. Based on regional geological map and Meso-Cenozoic basin map, the detailed statistical information of each airborne survey area, each airborne radioactive anomalous point and high field point can be presented visually by combining geological or basin research result. The successful development of this system will provide a fairly good base and platform for management of archives and data of airborne geophysical survey achievements in nuclear industry. (authors)

Estimating Gravity Biases with Wavelets in Support of a 1-cm Accurate Geoid Model

Science.gov (United States)

Ahlgren, K.; Li, X.

2017-12-01

Systematic errors that reside in surface gravity datasets are one of the major hurdles in constructing a high-accuracy geoid model at high resolutions. The National Oceanic and Atmospheric Administration's (NOAA) National Geodetic Survey (NGS) has an extensive historical surface gravity dataset consisting of approximately 10 million gravity points that are known to have systematic biases at the mGal level (Saleh et al. 2013). As most relevant metadata is absent, estimating and removing these errors to be consistent with a global geopotential model and airborne data in the corresponding wavelength is quite a difficult endeavor. However, this is crucial to support a 1-cm accurate geoid model for the United States. With recently available independent gravity information from GRACE/GOCE and airborne gravity from the NGS Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project, several different methods of bias estimation are investigated which utilize radial basis functions and wavelet decomposition. We estimate a surface gravity value by incorporating a satellite gravity model, airborne gravity data, and forward-modeled topography at wavelet levels according to each dataset's spatial wavelength. Considering the estimated gravity values over an entire gravity survey, an estimate of the bias and/or correction for the entire survey can be found and applied. In order to assess the accuracy of each bias estimation method, two techniques are used. First, each bias estimation method is used to predict the bias for two high-quality (unbiased and high accuracy) geoid slope validation surveys (GSVS) (Smith et al. 2013 & Wang et al. 2017). Since these surveys are unbiased, the various bias estimation methods should reflect that and provide an absolute accuracy metric for each of the bias estimation methods. Secondly, the corrected gravity datasets from each of the bias estimation methods are used to build a geoid model. The accuracy of each geoid model

Remote sensing, airborne radiometric survey and aeromagnetic survey data processing and analysis

International Nuclear Information System (INIS)

Dong Xiuzhen; Liu Dechang; Ye Fawang; Xuan Yanxiu

2009-01-01

Taking remote sensing data, airborne radiometric data and aero magnetic survey data as an example, the authors elaborate about basic thinking of remote sensing data processing methods, spectral feature analysis and adopted processing methods, also explore the remote sensing data combining with the processing of airborne radiometric survey and aero magnetic survey data, and analyze geological significance of processed image. It is not only useful for geological environment research and uranium prospecting in the study area, but also reference to applications in another area. (authors)

A flight test of the strapdown airborne gravimeter SGA-WZ in Greenland

DEFF Research Database (Denmark)

Zhao, Lei; Forsberg, René; Wu, Meiping

2015-01-01

-WZ strapdown airborne gravimeter in Greenland, in an area with good gravity coverage from earlier marine and airborne surveys. An overview of this new system SGA-WZ is given, including system design, sensor performance and data processing. The processing of the SGA-WZ includes a 160 s length finite impulse...

Alternative analysis of airborne laser data collected within conventional multi-parameter airborne geophysical surveys

Science.gov (United States)

Ahl, Andreas; Supper, R.; Motschka, K.; Schattauer, I.

2010-05-01

For the interpretation of airborne gamma-ray spectrometry as well as airborne electromagnetics it is of great importance to determine the distance between the geophysical sensor and the ground surface. Since radar altimeters do not penetrate vegetation, laser altimeters became popular in airborne geophysics over the past years. Currently the airborne geophysical platform of the Geological Survey of Austria (GBA) is equipped with a Riegl LD90-3800VHS-FLP high resolution laser altimeter, measuring the distances according to the first and the last reflected pulse. The goal of the presented study was to explore the possibilities of deriving additional information about the survey area from the laser data and to determine the accuracy of such results. On one hand the difference between the arrival time of the first and the last reflected pulse can be used to determine the height of the vegetation. This parameter is for example important for the correction of damping effects on airborne gamma-ray measurements caused by vegetation. Moreover especially for groundwater studies at catchment scale, this parameter can also be applied to support the spatial assessment of evapotranspiration. In combination with the altitude above geoid, determined by a GPS receiver, a rough digital elevation model of the survey area can be derived from the laser altimetry. Based on a data set from a survey area in the northern part of Austria, close to the border with the Czech Republic, the reliability of such a digital elevation model and the calculated vegetation height was tested. In this study a mean deviation of -1.4m, with a standard deviation of ±3.4m, between the digital elevation model from Upper Austria (25m spatial resolution) and the determined elevation model was determined. We also found an obvious correlation between the calculated vegetation heights greater 15m and the mapped forest published by the ‘Department of Forest Inventory' of the ‘Federal Forest Office' of Austria

Geophex airborne unmanned survey system

International Nuclear Information System (INIS)

Won, I.J.; Taylor, D.W.A.

1995-01-01

The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This nonintrusive system will provide open-quotes stand-offclose quotes capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits two operators to rapidly conduct geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance, of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak anomalies can be detected

Advances and Best Practices in Airborne Gravimetry from the U.S. GRAV-D Project

Science.gov (United States)

Diehl, Theresa; Childers, Vicki; Preaux, Sandra; Holmes, Simon; Weil, Carly

2013-04-01

The Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project, an official policy of the U.S. National Geodetic Survey as of 2007, is working to survey the entire U.S. and its holdings with high-altitude airborne gravimetry. The goal of the project is to provide a consistent, high-quality gravity dataset that will become the cornerstone of a new gravimetric geoid and national vertical datum in 2022. Over the last five years, the GRAV-D project has surveyed more than 25% of the country, accomplishing almost 500 flights on six different aircraft platforms and producing more than 3.7 Million square km of data thus far. This wealth of experience has led to advances in the collection, processing, and evaluation of high-altitude (20,000 - 35,000 ft) airborne gravity data. This presentation will highlight the most important practical and theoretical advances of the GRAV-D project, giving an introduction to each. Examples of innovation include: 1. Use of navigation grade inertial measurement unit data and precise lever arm measurements for positioning; 2. New quality control tests and software for near real-time analysis of data in the field; 3. Increased accuracy of gravity post-processing by reexamining assumptions and simplifications that were inconsistent with a goal of 1 mGal precision; and 4. Better final data evaluation through crossovers, additional statistics, and inclusion of airborne data into harmonic models that use EGM08 as a base model. The increases in data quality that resulted from implementation of the above advances (and others) will be shown with a case study of the GRAV-D 2008 southern Alaska survey near Anchorage, over Cook Inlet. The case study's statistics and comparisons to global models illustrate the impact that these advances have had on the final airborne gravity data quality. Finally, the presentation will summarize the best practices identified by the project from its last five years of experience.

Full Tensor Gradient of Simulated Gravity Data for Prospect Scale Delineation

Directory of Open Access Journals (Sweden)

Hendra Grandis

2014-07-01

Full Text Available Gravity gradiometry measurement allows imaging of anomalous sources in more detail than conventional gravity data. The availability of this new technique is limited to airborne gravity surveys using very specific instrumentation. In principle, the gravity gradients can be calculated from the vertical component of the gravity commonly measured in a ground-based gravity survey. We present a calculation of the full tensor gradient (FTG of the gravity employing the Fourier transformation. The calculation was applied to synthetic data associated with a simple block model and also with a more realistic model. The latter corresponds to a 3D model in which a thin coal layer is embedded in a sedimentary environment. Our results show the utility of the FTG of the gravity for prospect scale delineation.

Geophex airborne unmanned survey system

Energy Technology Data Exchange (ETDEWEB)

Won, I.J.; Taylor, D.W.A.

1995-03-01

The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This nonintrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits two operators to rapidly conduct geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance, of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak anomalies can be detected.

Gsolve, a Python computer program with a graphical user interface to transform relative gravity survey measurements to absolute gravity values and gravity anomalies

Science.gov (United States)

McCubbine, Jack; Tontini, Fabio Caratori; Stagpoole, Vaughan; Smith, Euan; O'Brien, Grant

2018-01-01

A Python program (Gsolve) with a graphical user interface has been developed to assist with routine data processing of relative gravity measurements. Gsolve calculates the gravity at each measurement site of a relative gravity survey, which is referenced to at least one known gravity value. The tidal effects of the sun and moon, gravimeter drift and tares in the data are all accounted for during the processing of the survey measurements. The calculation is based on a least squares formulation where the difference between the absolute gravity at each surveyed location and parameters relating to the dynamics of the gravimeter are minimized with respect to the relative gravity observations, and some supplied gravity reference site values. The program additionally allows the user to compute free air gravity anomalies, with respect to the GRS80 and GRS67 reference ellipsoids, from the determined gravity values and calculate terrain corrections at each of the surveyed sites using a prism formula and a user supplied digital elevation model. This paper reviews the mathematical framework used to reduce relative gravimeter survey observations to gravity values. It then goes on to detail how the processing steps can be implemented using the software.

Evaluation and Comparison of the Processing Methods of Airborne Gravimetry Concerning the Errors Effects on Downward Continuation Results: Case Studies in Louisiana (USA) and the Tibetan Plateau (China).

Science.gov (United States)

Zhao, Qilong; Strykowski, Gabriel; Li, Jiancheng; Pan, Xiong; Xu, Xinyu

2017-05-25

Gravity data gaps in mountainous areas are nowadays often filled in with the data from airborne gravity surveys. Because of the errors caused by the airborne gravimeter sensors, and because of rough flight conditions, such errors cannot be completely eliminated. The precision of the gravity disturbances generated by the airborne gravimetry is around 3-5 mgal. A major obstacle in using airborne gravimetry are the errors caused by the downward continuation. In order to improve the results the external high-accuracy gravity information e.g., from the surface data can be used for high frequency correction, while satellite information can be applying for low frequency correction. Surface data may be used to reduce the systematic errors, while regularization methods can reduce the random errors in downward continuation. Airborne gravity surveys are sometimes conducted in mountainous areas and the most extreme area of the world for this type of survey is the Tibetan Plateau. Since there are no high-accuracy surface gravity data available for this area, the above error minimization method involving the external gravity data cannot be used. We propose a semi-parametric downward continuation method in combination with regularization to suppress the systematic error effect and the random error effect in the Tibetan Plateau; i.e., without the use of the external high-accuracy gravity data. We use a Louisiana airborne gravity dataset from the USA National Oceanic and Atmospheric Administration (NOAA) to demonstrate that the new method works effectively. Furthermore, and for the Tibetan Plateau we show that the numerical experiment is also successfully conducted using the synthetic Earth Gravitational Model 2008 (EGM08)-derived gravity data contaminated with the synthetic errors. The estimated systematic errors generated by the method are close to the simulated values. In addition, we study the relationship between the downward continuation altitudes and the error effect. The

Evaluation and Comparison of the Processing Methods of Airborne Gravimetry Concerning the Errors Effects on Downward Continuation Results: Case Studies in Louisiana (USA) and the Tibetan Plateau (China)

Science.gov (United States)

Zhao, Q.

2017-12-01

Gravity data gaps in mountainous areas are nowadays often filled in with the data from airborne gravity surveys. Because of the errors caused by the airborne gravimeter sensors, and because of rough flight conditions, such errors cannot be completely eliminated. The precision of the gravity disturbances generated by the airborne gravimetry is around 3-5 mgal. A major obstacle in using airborne gravimetry are the errors caused by the downward continuation. In order to improve the results the external high-accuracy gravity information e.g., from the surface data can be used for high frequency correction, while satellite information can be applying for low frequency correction. Surface data may be used to reduce the systematic errors, while regularization methods can reduce the random errors in downward continuation. Airborne gravity surveys are sometimes conducted in mountainous areas and the most extreme area of the world for this type of survey is the Tibetan Plateau. Since there are no high-accuracy surface gravity data available for this area, the above error minimization method involving the external gravity data cannot be used. We propose a semi-parametric downward continuation method in combination with regularization to suppress the systematic error effect and the random error effect in the Tibetan Plateau; i.e., without the use of the external high-accuracy gravity data. We use a Louisiana airborne gravity dataset from the USA National Oceanic and Atmospheric Administration (NOAA) to demonstrate that the new method works effectively. Furthermore, and for the Tibetan Plateau we show that the numerical experiment is also successfully conducted using the synthetic Earth Gravitational Model 2008 (EGM08)-derived gravity data contaminated with the synthetic errors. The estimated systematic errors generated by the method are close to the simulated values. In addition, we study the relationship between the downward continuation altitudes and the error effect. The

Airborne Multi-Spectral Minefield Survey

Science.gov (United States)

2005-05-01

Swedish Defence Research Agency), GEOSPACE (Austria), GTD ( Ingenieria de Sistemas y Software Industrial, Spain), IMEC (Ineruniversity MicroElectronic...RTO-MP-SET-092 18 - 1 UNCLASSIFIED/UNLIMITED UNCLASSIFIED/UNLIMITED Airborne Multi-Spectral Minefield Survey Dirk-Jan de Lange, Eric den...actions is the severe lack of baseline information. To respond to this in a rapid way, cost-efficient data acquisition methods are a key issue. de

Downward continuation of airborne gravity data by means of the change of boundary approach

Science.gov (United States)

Mansi, A. H.; Capponi, M.; Sampietro, D.

2018-03-01

Within the modelling of gravity data, a common practice is the upward/downward continuation of the signal, i.e. the process of continuing the gravitational signal in the vertical direction away or closer to the sources, respectively. The gravity field, being a potential field, satisfies the Laplace's equation outside the masses and this means that it allows to unambiguously perform this analytical continuation only in a source-free domain. The analytical continuation problem has been solved both in the space and spectral domains by exploiting different algorithms. As well known, the downward continuation operator, differently from the upward one, is an unstable operator, due to its spectral characteristics similar to those of a high-pass filter, and several regularization methods have been proposed in order to stabilize it. In this work, an iterative procedure to downward/upward continue the gravity field observations, acquired at different altitudes, is proposed. This methodology is based on the change of boundary principle and it has been expressively thought for aerogravimetric observations for geophysical exploration purposes. Within this field of application, usually several simplifications can be applied, basically due to the specific characteristics of the airborne surveys which are usually flown at almost constant altitude as close as possible to the terrain. For instance, these characteristics, as shown in the present work, allow to perform the downward continuation without the need of any regularization. The goodness of the proposed methodology has been evaluated by means of a numerical test on real data, acquired in the South of Australia. The test shows that it is possible to move the aerogravimetric data, acquired along tracks with a maximum height difference of about 250 m, with accuracies of the order of 10^{-3} mGal.

Airborne geoid mapping of land and sea areas of East Malaysia

Science.gov (United States)

Jamil, H.; Kadir, M.; Forsberg, R.; Olesen, A.; Isa, M. N.; Rasidi, S.; Mohamed, A.; Chihat, Z.; Nielsen, E.; Majid, F.; Talib, K.; Aman, S.

2017-02-01

This paper describes the development of a new geoid-based vertical datum from airborne gravity data, by the Department of Survey and Mapping Malaysia, on land and in the South China Sea out of the coast of East Malaysia region, covering an area of about 610,000 square kilometres. More than 107,000 km flight line of airborne gravity data over land and marine areas of East Malaysia has been combined to provide a seamless land-to-sea gravity field coverage; with an estimated accuracy of better than 2.0 mGal. The iMAR-IMU processed gravity anomaly data has been used during a 2014-2016 airborne survey to extend a composite gravity solution across a number of minor gaps on selected lines, using a draping technique. The geoid computations were all done with the GRAVSOFT suite of programs from DTU-Space. EGM2008 augmented with GOCE spherical harmonic model has been used to spherical harmonic degree N = 720. The gravimetric geoid first was tied at one tide-gauge (in Kota Kinabalu, KK2019) to produce a fitted geoid, my_geoid2017_fit_kk. The fitted geoid was offset from the gravimetric geoid by +0.852 m, based on the comparison at the tide-gauge benchmark KK2019. Consequently, orthometric height at the six other tide gauge stations was computed from HGPS Lev = hGPS - Nmy_geoid2017_.t_kk. Comparison of the conventional (HLev) and GPS-levelling heights (HGPS Lev) at the six tide gauge locations indicate RMS height difference of 2.6 cm. The final gravimetric geoidwas fitted to the seven tide gauge stations and is known as my_geoid2017_fit_east. The accuracy of the gravimetric geoid is estimated to be better than 5 cm across most of East Malaysia land and marine areas

Integrating stations from the North America Gravity Database into a local GPS-based land gravity survey

Science.gov (United States)

Shoberg, Thomas G.; Stoddard, Paul R.

2013-01-01

The ability to augment local gravity surveys with additional gravity stations from easily accessible national databases can greatly increase the areal coverage and spatial resolution of a survey. It is, however, necessary to integrate such data seamlessly with the local survey. One challenge to overcome in integrating data from national databases is that these data are typically of unknown quality. This study presents a procedure for the evaluation and seamless integration of gravity data of unknown quality from a national database with data from a local Global Positioning System (GPS)-based survey. The starting components include the latitude, longitude, elevation and observed gravity at each station location. Interpolated surfaces of the complete Bouguer anomaly are used as a means of quality control and comparison. The result is an integrated dataset of varying quality with many stations having GPS accuracy and other reliable stations of unknown origin, yielding a wider coverage and greater spatial resolution than either survey alone.

Survey of subsurface geophysical exploration technologies adaptable to an airborne platform

International Nuclear Information System (INIS)

Taylor, K.A.

1992-12-01

This report has been prepared by the US Department of Energy (DOE) as part of a Research Development Demonstration Testing and Evaluation (RDDT ampersand E) project by EG ampersand G Energy Measurement's (EG ampersand G/EM) Remote Sensing Laboratory. It examines geophysical detection techniques which may be used in Environmental Restoration/Waste Management (ER/WM) surveys to locate buried waste, waste containers, potential waste migratory paths, and aquifer depths. Because of the Remote Sensing Laboratory's unique survey capabilities, only those technologies which have been adapted or are capable of being adapted to an airborne platform were studied. This survey describes several of the available subsurface survey technologies and discusses the basic capabilities of each: the target detectability, required geologic conditions, and associated survey methods. Because the airborne capabilities of these survey techniques have not been fully developed, the chapters deal mostly with the ground-based capabilities of each of the technologies, with reference made to the airborne capabilities where applicable. The information about each survey technique came from various contractors whose companies employ these specific technologies. EG ampersand G/EM cannot guarantee or verify the accuracy of the contractor information; however, the data given is an indication of the technologies that are available

Waste Isolation Pilot Plant (WIPP) site gravity survey and interpretation

International Nuclear Information System (INIS)

Barrows, L.J.; Fett, J.D.

1983-04-01

A portion of the WIPP site has been extensively surveyed with high-precision gravity. The main survey (in T22S, R31E) covered a rectangular area 2 by 4-1/3 mi encompassing all of WIPP site Zone II and part of the disturbed zone to the north of the site. Stations were at 293-ft intervals along 13 north-south lines 880 ft apart. The data are considered accurate to within a few hundredths of a milligal. Long-wavelength gravity anomalies correlate well with seismic time structures on horizons below the Castile Formation. Both the gravity anomalies and the seismic time structures are interpreted as resulting from related density and velocity variations within the Ochoan Series. Shorter wavelength negative gravity anomalies are interpreted as resulting from bulk density alteration in the vicinity of karst conduits. The WIPP gravity survey was unable to resolve low-amplitude, long-wavelength anomalies that should result from the geologic structures within the disturbed zone. It did indicate the degree and character of karst development within the surveyed area

Merging airborne and carborne radiometric data for surveying the Deir Az-Zor area, Syria

International Nuclear Information System (INIS)

Jubeli, Y.M.; Aissa, M.; Al-Hent, R.

1997-01-01

To complete the radiometric map of Syria, and to estimate the natural background radiation levels for environmental monitoring, a carborne survey was undertaken over the Deir Az-Zor area. This area was not covered by a previous airborne survey, except for peripheral regions in the south and west. To complete the radiometric map, results of the carborne and airborne surveys had to be merged. This paper presents the merging procedure which was used after normalizing the two data sets to match each other. No anomalies suitable for radioelement exploration were found. However, the overall radiometric maps resulting from the present work were consistent with the maps of the areas covered by the airborne survey. (author)

New approach to airborne monitoring of radioactive pollution

International Nuclear Information System (INIS)

Hoeschl, V.; Jurza, P.; Pavlik, B.

1997-01-01

The use of remote sensing methods in the monitoring of an environment is increasing. The best results are obtained when various types of exploration methods are available. This paper presents the use of airborne gamma ray methods, which can be included in a wide scope of works related to environmental problems. It may concern uranium mining areas, areas surrounding various nuclear facilities or areas of Chernobyl fallout. Gamma ray spectrometry data can be combined with airborne magnetic, surface gravity and satellite imagery data to obtain maximum information in data output. Airborne geophysics is able to detect and delineate radioactive contamination and to find important geological trends defining the geological structure of the monitored area. Our company PICODAS Prague Ltd. introduces new sophisticated airborne instrumentation as well as up-to-date data processing and data presentation techniques. In the Czech Cretaceous, a long term project, ''The Structurally-tectonic Survey of the South-West Foreland of the Straz Deposit'' has been undertaken, concerning the ecological load on the environment, especially the pollution of the underground water level horizons due to uranium mining in that area. The major interest is the complicated tectonic structure which interferes heavily with the hydrogeological situation of the region. The paper presents the results of airborne surveys and the interpretation of other geophysical data from the surroundings of Straz pod Ralskem and from Karlovy Vary. (author)

Airborne geophysical survey, Wind River Basin area, Wyoming

International Nuclear Information System (INIS)

1974-01-01

Results are reported of AEC-sponsored, high sensitivity, reconnaisance airborne gamma-ray survey of the Wind River Basin area, Wyoming. The objective of the survey was to define those areas showing surface indications of a generally higher uranium content (uraniferous provinces) and where detailed exploration for uranium would most likely be successful. For the data collection tasks, a TI high sensitivity gamma-ray system consisting of seven large-volume NaI detectors, two 400-channel analyzers, and ancillary geophysical and electronic equipment was used. Gamma-ray spectrometric data were processed to correct for variations in atmospheric and flight conditions and statistically evaluated to remove the effect of surface geologic variations. Data were then compared to regional geomorphic lineaments derived from ERTS-1 imagery. Aeromagnetic data were collected simultaneously with the airborne gamma-ray survey and interpreted in terms of regional structure. Ten major anomalous uranium areas and ten less strong anomalous areas were defined within the region surveyed. These anomalies and the known mining districts and uranium occurrences demonstrated good correlation with the ERTS lineaments. The basins were defined by the aeromagnetic data. It is suggested that gamma-ray spectrometer data be supplemented by both the ERTS and aeromagnetic data to best define the targets of greatest potential for further exploration. (U.S.)

Results from a U.S. Absolute Gravity Survey,

Science.gov (United States)

1982-01-01

National Bureau of Standards. La . ... ,., 831A08 NOV -2- 1. Introduction We have recently completed an absolute gravity survey at twelve sites in the...Air Force Geophysics Laboratory (AFGL) and the Istituto di Metrologia -7- "G. Colonnetti" (IMGC) [Marson and Alasia, 1978, 19801. All three...for ab- solute measurements of the earth’s gravity, Metrologia , in press, 1982. L 4 !" Table 1. Gravity values transferred to the floor in gal (cm

Ultrafine particles over Eastern Australia: an airborne survey

Directory of Open Access Journals (Sweden)

Wolfgang Junkermann

2015-04-01

Full Text Available Ultrafine particles (UFP in the atmosphere may have significant impacts on the regional water and radiation budgets through secondary effects on cloud microphysics. Yet, as these particles are invisible for current remote sensing techniques, knowledge about their three-dimensional distribution, source strengths and budgets is limited. Building on a 40-yr-old Australia-wide airborne survey which provides a reference case study of aerosol sources and budgets, this study presents results from a new airborne survey over Eastern Australia, northern New South Wales and Queensland. Observations identified apparent changes in the number and distribution of major anthropogenic aerosol sources since the early 1970s, which might relate to the simultaneously observed changes in rainfall patterns over eastern Queensland. Coal-fired power stations in the inland areas between Brisbane and Rockhampton were clearly identified as the major sources for ultrafine particulate matter. Sugar mills, smelters and shipping along the coast close to the Ports of Townsville and Rockhampton were comparable minor sources. Airborne Lagrangian plume studies were applied to investigate source strength and ageing properties within power station plumes. Significant changes observed, compared to the measurements in the 1970s, included a significant increase in the number concentration of UFP related to coal-fired power station emissions in the sparsely populated Queensland hinterland coincident with the area with the most pronounced reduction in rainfall.

Airborne VLF survey of Izu-Oshima volcano

Energy Technology Data Exchange (ETDEWEB)

Murakami, Yutaka; Yukutake, Takeshi

1988-05-17

Resistivity distribution in underground indicates anomaly in some cases due to volcanic activity, airborne VLF survey of Izu-Oshima volcano in whole area was carried out by measurement of the anomalous vertical magnetic field. The flight direction was determined with reference to both of the transmitter direction of the VLF waves and the running direction of the geologic formation. The flight altitude and the flight lines spacing were 100 m and 200 m respectively. Typical profiles of four lines of measurement were investigated. The resistivity anomalies were indicated corresponding to the position of known geologic fissure line, the lip of the caldera, the line of the craters and side volcanos. Several anomalous trends were detected by the contour drawing of the Fraser filter output. The detected results were as follow: new volcanos with the resistivity anomaly, the resistivity anomalies spread to the north-northwest from Goshinka jaya, the anomalies due to flowed lava, the anomalies by encroached water from the caldera wall, the effects from side volcanoes and so on. The resistivity anomalies by airborne VLF survey correspond to the known volcanic activities, and they are useful for elucidation of the underground volcanism. (6 figs, 4 refs)

Crustal structure beneath the Paleozoic Parnaíba Basin revealed by airborne gravity and magnetic data, Brazil

Science.gov (United States)

de Castroa, David L.; Fuck, Reinhardt A.; Phillips, Jeffrey D.; Vidotti, Roberta M.; Bezerra, Francisco H. R.; Dantas, Elton L.

2014-01-01

The Parnaíba Basin is a large Paleozoic syneclise in northeastern Brazil underlain by Precambrian crystalline basement, which comprises a complex lithostructural and tectonic framework formed during the Neoproterozoic–Eopaleozoic Brasiliano–Pan African orogenic collage. A sag basin up to 3.5 km thick and 1000 km long formed after the collage. The lithologic composition, structure, and role in the basin evolution of the underlying basement are the focus of this study. Airborne gravity and magnetic data were modeled to reveal the general crustal structure underneath the Parnaíba Basin. Results indicate that gravity and magnetic signatures delineate the main boundaries and structural trends of three cratonic areas and surrounding Neoproterozoic fold belts in the basement. Triangular-shaped basement inliers are geophysically defined in the central region of this continental-scale Neoproterozoic convergence zone. A 3-D gravity inversion constrained by seismological data reveals that basement inliers exhibit a 36–40.5 km deep crustal root, with borders defined by a high-density and thinner crust. Forward modeling of gravity and magnetic data indicates that lateral boundaries between crustal units are limited by Brasiliano shear zones, representing lithospheric sutures of the Amazonian and São Francisco Cratons, Tocantins Province and Parnaíba Block. In addition, coincident residual gravity, residual magnetic, and pseudo-gravity lows indicate two complex systems of Eopaleozoic rifts related to the initial phase of the sag deposition, which follow basement trends in several directions.

Airborne electromagnetic and magnetic survey data of the Paradox and San Luis Valleys, Colorado

Science.gov (United States)

Ball, Lyndsay B.; Bloss, Benjamin R.; Bedrosian, Paul A.; Grauch, V.J.S.; Smith, Bruce D.

2015-01-01

In October 2011, the U.S. Geological Survey (USGS) contracted airborne magnetic and electromagnetic surveys of the Paradox and San Luis Valleys in southern Colorado, United States. These airborne geophysical surveys provide high-resolution and spatially comprehensive datasets characterizing the resistivity structure of the shallow subsurface of each survey region, accompanied by magnetic-field information over matching areas. These data were collected to provide insight into the distribution of groundwater brine in the Paradox Valley, the extent of clay aquitards in the San Luis Valley, and to improve our understanding of the geologic framework for both regions. This report describes these contracted surveys and releases digital data supplied under contract to the USGS.

Development of instrumentation for airborne radiometric surveys in the Atomic Minerals Division: Past, present, and future

International Nuclear Information System (INIS)

Sreehari, R.

1993-01-01

A high-sensitivity airborne gamma-ray spectrometric and magnetic survey system, using Na(Tl) detector volume of 50,000 cc for 4π and 4195 cc for 2π geometry applications, was designed, developed, and fabricated in 1978 and was flown for airborne surveys in various parts of India for over a decade. A compact complementary metal-oxide-semiconductor (CMOS) logic circuit based high-sensitivity airborne gamma-ray spectrometric and magnetic survey system with high noise-immunity using Na(Tl) detector volume of 50,000 cc for 4π and 12,500 cc for 2π geometry applications was developed and interfaced to an Inertial Navigation System in 1988. The system currently in use was flown extensively for airborne surveys in various parts of India for the Atomic Minerals Division, Oil and Natural Gas Commission, and Nuclear Power Corporation. The design aspects of the present system have been discussed. A microprocessor based DDAS and multichannel analysers, having on-line micro terminal and on-line corrections for Compton scatter, and background radiation to obtain corrected analog profiles for the spectrometric data, are currently under development. The design aspects of these units are described and evaluated for future high-sensitivity airborne gamma-ray spectrometric surveys with Nal(Tl) detector volumes similar to those of the present system. (author). 8 refs., 3 figs., 1 tab

From Discrete Gravity Survey Data to a High-resolution Gravity Field Representation in the Nordic-Baltic Region

DEFF Research Database (Denmark)

Märdla, Silja; Ågren, Jonas; Strykowski, Gabriel

2017-01-01

The deduction of a regularly spaced gravity anomaly grid from scattered survey data is studied, addressing mainly two aspects: reduction of gravity to anomalies and subsequent interpolation by various methods. The problem is illustrated in a heterogeneous study area and contrasting test areas inc...

Determining a pre-mining radiological baseline from historic airborne gamma surveys: A case study

International Nuclear Information System (INIS)

Bollhöfer, Andreas; Beraldo, Annamarie; Pfitzner, Kirrilly; Esparon, Andrew; Doering, Che

2014-01-01

Knowing the baseline level of radioactivity in areas naturally enriched in radionuclides is important in the uranium mining context to assess radiation doses to humans and the environment both during and after mining. This information is particularly useful in rehabilitation planning and developing closure criteria for uranium mines as only radiation doses additional to the natural background are usually considered ‘controllable’ for radiation protection purposes. In this case study we have tested whether the method of contemporary groundtruthing of a historic airborne gamma survey could be used to determine the pre-mining radiological conditions at the Ranger mine in northern Australia. The airborne gamma survey was flown in 1976 before mining started and groundtruthed using ground gamma dose rate measurements made between 2007 and 2009 at an undisturbed area naturally enriched in uranium (Anomaly 2) located nearby the Ranger mine. Measurements of 226 Ra soil activity concentration and 222 Rn exhalation flux density at Anomaly 2 were made concurrent with the ground gamma dose rate measurements. Algorithms were developed to upscale the ground gamma data to the same spatial resolution as the historic airborne gamma survey data using a geographic information system, allowing comparison of the datasets. Linear correlation models were developed to estimate the pre-mining gamma dose rates, 226 Ra soil activity concentrations, and 222 Rn exhalation flux densities at selected areas in the greater Ranger region. The modelled levels agreed with measurements made at the Ranger Orebodies 1 and 3 before mining started, and at environmental sites in the region. The conclusion is that our approach can be used to determine baseline radiation levels, and provide a benchmark for rehabilitation of uranium mines or industrial sites where historical airborne gamma survey data are available and an undisturbed radiological analogue exists to groundtruth the data. - Highlights: �

Air sampling system for airborne surveys

International Nuclear Information System (INIS)

Jupiter, C.; Tipton, W.J.

1975-01-01

An air sampling system has been designed for installation on the Beechcraft King Air A-100 aircraft as a part of the Aerial Radiological Measuring System (ARMS). It is intended for both particle and whole gas sampling. The sampling probe is designed for isokinetic sampling and is mounted on a removable modified escape hatch cover, behind the co-pilot's seat, and extends about two feet forward of the hatch cover in the air stream lines. Directly behind the sampling probe inside the modified hatch cover is an expansion chamber, space for a 5-inch diameter filter paper cassette, and an optional four-stage cascade impactor for particle size distribution measurements. A pair of motors and blower pumps provide the necessary 0.5 atmosphere pressure across the type MSA 1106 B glass fiber filter paper to allow a flow rate of 50 cfm. The MSA 1106 B filter paper is designed to trap sub-micrometer particles with a high efficiency; it was chosen to enable a quantitative measurement of airborne radon daughters, one of the principal sources of background signals when radiological surveys are being performed. A venturi section and pressure gauges allow air flow rate measurements so that airborne contaminant concentrations may be quantified. A whole gas sampler capable of sampling a cubic meter of air is mounted inside the aircraft cabin. A nuclear counting system on board the aircraft provides capability for α, β and γ counting of filter paper samples. Design data are presented and types of survey missions which may be served by this system are described

Airborne gravimetry used in precise geoid computations by ring integration

DEFF Research Database (Denmark)

Kearsley, A.H.W.; Forsberg, René; Olesen, Arne Vestergaard

1998-01-01

Two detailed geoids have been computed in the region of North Jutland. The first computation used marine data in the offshore areas. For the second computation the marine data set was replaced by the sparser airborne gravity data resulting from the AG-MASCO campaign of September 1996. The results...... of comparisons of the geoid heights at on-shore geometric control showed that the geoid heights computed from the airborne gravity data matched in precision those computed using the marine data, supporting the view that airborne techniques have enormous potential for mapping those unsurveyed areas between...

Comparison of survey and photogrammetry methods to position gravity data, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Ponce, D.A.; Wu, S.S.C.; Spielman, J.B.

1985-01-01

Locations of gravity stations at Yucca Mountain, Nevada, were determined by a survey using an electronic distance-measuring device and by a photogram-metric method. The data from both methods were compared to determine if horizontal and vertical coordinates developed from photogrammetry are sufficently accurate to position gravity data at the site. The results show that elevations from the photogrammetric data have a mean difference of 0.57 +- 0.70 m when compared with those of the surveyed data. Comparison of the horizontal control shows that the two methods agreed to within 0.01 minute. At a latitude of 45 0 , an error of 0.01 minute (18 m) corresponds to a gravity anomaly error of 0.015 mGal. Bouguer gravity anomalies are most sensitive to errors in elevation, thus elevation is the determining factor for use of photogrammetric or survey methods to position gravity data. Because gravity station positions are difficult to locate on aerial photographs, photogrammetric positions are not always exactly at the gravity station; therefore, large disagreements may appear when comparing electronic and photogrammetric measurements. A mean photogrammetric elevation error of 0.57 m corresponds to a gravity anomaly error of 0.11 mGal. Errors of 0.11 mGal are too large for high-precision or detailed gravity measurements but acceptable for regional work. 1 ref. 2 figs., 4 tabs

New Antarctic Gravity Anomaly Grid for Enhanced Geodetic and Geophysical Studies in Antarctica.

Science.gov (United States)

Scheinert, M; Ferraccioli, F; Schwabe, J; Bell, R; Studinger, M; Damaske, D; Jokat, W; Aleshkova, N; Jordan, T; Leitchenkov, G; Blankenship, D D; Damiani, T M; Young, D; Cochran, J R; Richter, T D

2016-01-28

Gravity surveying is challenging in Antarctica because of its hostile environment and inaccessibility. Nevertheless, many ground-based, airborne and shipborne gravity campaigns have been completed by the geophysical and geodetic communities since the 1980s. We present the first modern Antarctic-wide gravity data compilation derived from 13 million data points covering an area of 10 million km 2 , which corresponds to 73% coverage of the continent. The remove-compute-restore technique was applied for gridding, which facilitated levelling of the different gravity datasets with respect to an Earth Gravity Model derived from satellite data alone. The resulting free-air and Bouguer gravity anomaly grids of 10 km resolution are publicly available. These grids will enable new high-resolution combined Earth Gravity Models to be derived and represent a major step forward towards solving the geodetic polar data gap problem. They provide a new tool to investigate continental-scale lithospheric structure and geological evolution of Antarctica.

New Antarctic Gravity Anomaly Grid for Enhanced Geodetic and Geophysical Studies in Antarctica

Science.gov (United States)

Scheinert, M.; Ferraccioli, F.; Schwabe, J.; Bell, R.; Studinger, M.; Damaske, D.; Jokat, W.; Aleshkova, N.; Jordan, T.; Leitchenkov, G.; Blankenship, D. D.; Damiani, T. M.; Young, D.; Cochran, J. R.; Richter, T. D.

2018-01-01

Gravity surveying is challenging in Antarctica because of its hostile environment and inaccessibility. Nevertheless, many ground-based, airborne and shipborne gravity campaigns have been completed by the geophysical and geodetic communities since the 1980s. We present the first modern Antarctic-wide gravity data compilation derived from 13 million data points covering an area of 10 million km2, which corresponds to 73% coverage of the continent. The remove-compute-restore technique was applied for gridding, which facilitated levelling of the different gravity datasets with respect to an Earth Gravity Model derived from satellite data alone. The resulting free-air and Bouguer gravity anomaly grids of 10 km resolution are publicly available. These grids will enable new high-resolution combined Earth Gravity Models to be derived and represent a major step forward towards solving the geodetic polar data gap problem. They provide a new tool to investigate continental-scale lithospheric structure and geological evolution of Antarctica. PMID:29326484

Research on 3-D terrain correction methods of airborne gamma-ray spectrometry survey

International Nuclear Information System (INIS)

Liu Yanyang; Liu Qingcheng; Zhang Zhiyong

2008-01-01

The general method of height correction is not effectual in complex terrain during the process of explaining airborne gamma-ray spectrometry data, and the 2-D terrain correction method researched in recent years is just available for correction of section measured. A new method of 3-D sector terrain correction is studied. The ground radiator is divided into many small sector radiators by the method, then the irradiation rate is calculated in certain survey distance, and the total value of all small radiate sources is regarded as the irradiation rate of the ground radiator at certain point of aero- survey, and the correction coefficients of every point are calculated which then applied to correct to airborne gamma-ray spectrometry data. The method can achieve the forward calculation, inversion calculation and terrain correction for airborne gamma-ray spectrometry survey in complex topography by dividing the ground radiator into many small sectors. Other factors are considered such as the un- saturated degree of measure scope, uneven-radiator content on ground, and so on. The results of for- ward model and an example analysis show that the 3-D terrain correction method is proper and effectual. (authors)

Development of a new generation gravity map of Antarctica: ADGRAV Antarctic Digital Gravity Synthesis

Directory of Open Access Journals (Sweden)

R. A. Arko

1999-06-01

Full Text Available The U.S. National Science Foundation (NSF has agreed to support the development of a new generation gravity map of Antarctica (ADGRAV - Antarctic Digital Gravity Synthesis, funding the development of a web based access tool. The goal of this project is the creation of an on-line Antarctic gravity database which will facilitate access to improved high resolution satellite gravity models, in conjunction with shipboard, airborne, and land based gravity measurements for the continental regions. This database will complement parallel projects underway to develop new continental bedrock (BEDMAP and magnetic (ADMAP maps of Antarctica.

Environmental airborn radioactivity survey around Burg El Arab Area, Western desert, Egypt

International Nuclear Information System (INIS)

Fouad, K.M.; Ammar, A.A.; Meleik, M.L.

1977-01-01

An environmental airborne radioactivity survey of approximately 250 square kilometres of Burg El Arab area was conducted by the Airborne Geophysical survey Division of the Geology and Raw Materials Department. The environmental levels of gamma radiation are measured so as to determine quickly the amount and extent of any possible future increase in radioactivity levels of the area by the proposed nuclear facility through normal operations or any accident that may occur. The aerial radiometric measurements were obtained by a continuously recording airborne scintillometer type RVS-1. installed in an Antonoff-2 aircraft, flying at an average speed of 170 Km/h, at a nominal ground clearance of 50 m. The survey was carried out along 84 parallel flight lines directed N-S, and spaced 250 m apart. The area is shown on the geological map as composed of four lithological units. The analysis of the data has proved that these units correspond to six distinct levels of characteristic radioactivity, as two of the lithological units could each be separated into two radioactivity levels on the basis of the radioactivity pattern. The six radiometric levels are, from north to south, beach limy sediments (15 to 101. and 97 to 191 cps), detrital limestone (201 to 354 cpt), saline lakes and salt deposits (262 to 444 cps), and alluvial deposits (307 to 308 and 412 to 742 cps)

Research progress in airborne surveys of terrestrial gamma radiation

International Nuclear Information System (INIS)

Burson, Z.G.

1974-01-01

Progress during the last few years in airborne surveys of terrestrial gamma radiation, i.e. in the measuring, recording, and interpreting of gamma ray signals in NaI(Tl) crystals, is discussed. Non-terrestrial background contributions have been accurately characterized. The feasibility of determining the water equivalent of snow cover by aerial survey techniques has been demonstrated. Repeat surveys over areas surrounding reactor sites can now be used to detect average differences of less than 1.0 μR/hr in terrestrial gamma radiation levels. New data acquisition and recording systems allow isotope concentrations and total inventories to be measured in spatial resolutions of a few hundred feet. Aerial survey data have been combined with population distribution data to obtain population exposure values from natural terrestrial gamma radiation around reactor sites

Airborne geophysical surveys conducted in western Nebraska, 2010: contractor reports and data

Science.gov (United States)

,

2014-01-01

This report contains three contractor reports and data files for an airborne electromagnetic survey flown from June 28 to July 7, 2010. The first report; “SkyTEM Survey: Nebraska, USA, Data” describes data aquisition and processing from a time-domain electromagnetic and magnetic survey performed by SkyTEM Canada, Inc. (the North American SkyTEM subsidiary), in western Nebraska, USA. Digital data for this report are given in Appendix 1. The airborne geophysical data from the SkyTEM survey subsequently were processed and inverted by Aarhus Geophysics ApS, Aarhus, Denmark, to produce resistivity depth sections along each flight line. The result of that processing is described in two reports presented in Appendix 2, “Processing and inversion of SkyTEM data from USGS Area UTM–13” and “Processing and inversion of SkyTEM data from USGS Area UTM–14.” Funding for these surveys was provided by the North Platte Natural Resources District, the South Platte Natural Resources District, and the Twin Platte Natural Resources District, in Scottsbluff, Sidney, and North Platte, Nebraska, respectively. Any additional information concerning the geophysical data may be obtained from the U.S. Geological Survey Crustal Geophysics and Geochemistry Science Center, Denver Colorado.

The characteristics and interpretation of regional gravity, magnetic and radiometric surveys in the Pine Creek Geosyncline

International Nuclear Information System (INIS)

Tucker, D.H.; Stuart, D.C.; Hone, I.G.; Sampath, N.

1980-01-01

The Bureau of Mineral Resources, Geology and Geophysics (BMR) has covered the Pine Creek Geosyncline with helicopter gravity stations on an 11,000m grid, and airborne magnetic and gamma spectrometer surveys along east-west lines 150m above ground level and 1500m apart. These data are available as maps at various scales, and most recently at 1:500,000 scale to overlay a geological map of the region at the same scale (BMR 1979a, 1979b, 1979c and 1979d). Inspection of the new regional maps shows that most of the known uranium deposits lie in areas of magnetically disturbed metasediments near residual Bouguer anomaly lows associated with radioactive granites. Some of these regional associations have been reported elsewhere (Stephansson and Johnson, 1976; Horsfall and Wilkes, 1975; Tucker, Hone, Sampath and Ewers, 1979). To better understand the links between the regional geophysics and regional geology, BMR undertook a multidisciplinary investigation of the geophysical characteristics of the Pine Creek Geosyncline during 1977 and 1978. The investigation included detailed ground surveys over anomalies, field and laboratory studies of rock physical properties, mineralogy studies, geological mapping, and computer modelling of anomaly sources

SGA-WZ: A New Strapdown Airborne Gravimeter

DEFF Research Database (Denmark)

Huang, Yangming; Olesen, Arne Vestergaard; Wu, Meiping

2012-01-01

Inertial navigation systems and gravimeters are now routinely used to map the regional gravitational quantities from an aircraft with mGal accuracy and a spatial resolution of a few kilometers. However, airborne gravimeter of this kind is limited by the inaccuracy of the inertial sensor performance......, the integrated navigation technique and the kinematic acceleration determination. As the GPS technique developed, the vehicle acceleration determination is no longer the limiting factor in airborne gravity due to the cancellation of the common mode acceleration in differential mode. A new airborne gravimeter...... and discussion of the airborne field test results are also given....

Two-dimensional coherence analysis of magnetic and gravity data from the Cascer Quadrangle, Wyoming. Final report

International Nuclear Information System (INIS)

QEB, Inc. has completed a two-dimensional coherence analysis of gravity and magnetic data from the Casper, Wyoming NTMS quadrangle. Magnetic data from an airborne survey were reduced to produce a Residual Magnetic map, and gravity data obtained from several sources were reduced to produce a Complete Bouguer Gravity map. Both sets of data were upward continued to a plane one kilometer above the surface; and then, to make the magnetic and gravity data comparable, the magnetic data were transformed to pseudo-gravity data by the application of Poisson's relationship for rocks that are both dense and magnetic relative to the surrounding rocks. A pseudo-gravity map was then produced and an analysis made of the two-dimensional coherence between the upward continued Bouguer gravity and the pseudo-gravity data. Based on the results of the coherence analysis, digital filters were designed to either pass or reject wavelength bands with high coherence

Airborne gamma ray spectrometer surveying

International Nuclear Information System (INIS)

1991-01-01

The International Atomic Energy Agency (IAEA) in its role as collector and disseminator of information on nuclear techniques has long had an interest in gamma ray spectrometer methods and has published a number of Technical Reports on various aspects of the subject. At an Advisory Group Meeting held in Vienna in November 1986 to review appropriate activities the IAEA could take following the Chernobyl accident, it was recommended that preparation begin on a new Technical Report on airborne gamma ray spectrometer surveying, taking into account the use of the technique for environmental monitoring as well as for nuclear emergency response requirements. Shortly thereafter the IAEA became the lead organization in the Radioelement Geochemical Mapping section of the International Geological Correlation Programme/United Nations Educational, Scientific and Cultural Organization (UNESCO) Project on International Geochemical Mapping. These two factors led to the preparation of the present Technical Report. 18 figs, 4 tabs

Recent developments in airborne gamma ray surveying

International Nuclear Information System (INIS)

Grasty, Robert L.

1999-01-01

Standardized procedures have been developed for converting airborne gamma ray measurements to ground concentrations of potassium, uranium and thorium. These procedures make use of an airborne calibration range whose ground concentrations should be measured with a calibrated portable spectrometer rather than by taking geochemical samples. Airborne sensitivities and height attenuation coefficients are normally determined from flights over the calibration range but may not be applicable in mountainous areas. Mathematical techniques have been now developed to reduce statistical noise in the airborne measurements by utilizing up to 256 channels of spectral information. (author)

The gravity field and GGOS

DEFF Research Database (Denmark)

Forsberg, René; Sideris, M.G.; Shum, C.K.

2005-01-01

The gravity field of the earth is a natural element of the Global Geodetic Observing System (GGOS). Gravity field quantities are like spatial geodetic observations of potential very high accuracy, with measurements, currently at part-per-billion (ppb) accuracy, but gravity field quantities are also...... unique as they can be globally represented by harmonic functions (long-wavelength geopotential model primarily from satellite gravity field missions), or based on point sampling (airborne and in situ absolute and superconducting gravimetry). From a GGOS global perspective, one of the main challenges...... is to ensure the consistency of the global and regional geopotential and geoid models, and the temporal changes of the gravity field at large spatial scales. The International Gravity Field Service, an umbrella "level-2" IAG service (incorporating the International Gravity Bureau, International Geoid Service...

Karoo airborne geophysical survey

International Nuclear Information System (INIS)

Cole, D.J.; Stettler, E.H.

1984-01-01

Thirty four uranium anomalies were selected for ground follow-up from the analogue spectrometer records of Block 4 of the Karoo Airborne Geophysical Survey. The anomalies were plotted on 1:50 000 scale topographic maps and to 1:250 000 scale maps which are included in this report. The anomaly co-ordinates are tabulated together with the farms on which they occur. Results of the ground follow-up of the aerial anomalies are described. Twenty two anomalies are related to uranium mineralisation of which seventeen occur over baked mudstone adjacent to a dolerite intrusion. Five are located over fluvial channel sandstone of the Beaufort Group and subsurface mineralised sandstone may be present. The other twelve anomalies are spurious. Of the anomalies located over baked mudstone, fifteen emanate from ferruginous mudstone of the Whitehill Formation west of longitude 21 degrees 15 minutes. One of the two remaining anomalies over baked mudstone occurs over the Prince Albert Formation and the other anomaly is over baked mudstone and calcareous nodules of the Beaufort Group. The general low uranium values (less than 355 ppm eU3O8) render the occurrences uneconomic

Linear and non-linear Modified Gravity forecasts with future surveys

Science.gov (United States)

Casas, Santiago; Kunz, Martin; Martinelli, Matteo; Pettorino, Valeria

2017-12-01

Modified Gravity theories generally affect the Poisson equation and the gravitational slip in an observable way, that can be parameterized by two generic functions (η and μ) of time and space. We bin their time dependence in redshift and present forecasts on each bin for future surveys like Euclid. We consider both Galaxy Clustering and Weak Lensing surveys, showing the impact of the non-linear regime, with two different semi-analytical approximations. In addition to these future observables, we use a prior covariance matrix derived from the Planck observations of the Cosmic Microwave Background. In this work we neglect the information from the cross correlation of these observables, and treat them as independent. Our results show that η and μ in different redshift bins are significantly correlated, but including non-linear scales reduces or even eliminates the correlation, breaking the degeneracy between Modified Gravity parameters and the overall amplitude of the matter power spectrum. We further apply a Zero-phase Component Analysis and identify which combinations of the Modified Gravity parameter amplitudes, in different redshift bins, are best constrained by future surveys. We extend the analysis to two particular parameterizations of μ and η and consider, in addition to Euclid, also SKA1, SKA2, DESI: we find in this case that future surveys will be able to constrain the current values of η and μ at the 2-5% level when using only linear scales (wavevector k < 0 . 15 h/Mpc), depending on the specific time parameterization; sensitivity improves to about 1% when non-linearities are included.

Karoo airborne geophysical survey: preliminary report on airborne radiometric data from block 12

International Nuclear Information System (INIS)

Day, R.W.; Wright, O.M.

1980-02-01

The analogue gamma-ray spectrometer records of block 12 of the Karoo airborne geophysical survey were studied and significant uranium anomalies were selected and graded. The anomalies were plotted on 1:50 000 scale maps and the co-ordinates of the anomalies were tabulated. The anomalies were transferred to 1:250 000 scale maps which are included in this report. The geological setting of the anomalies has been studied. Ground follow-up work has been recommended for anomalies which occur over mineralized pans and drainage channels, and the Lower Beaufort Stage. Other anomalies which occur over the Ecca Series, the Middle Beaufort Stage, the Upper Beaufort Stage and the Stormberg Series have also been recommended for ground investigation

Interpretation of airborne geophysical data over the Aarons Pass Granite, near Mudgee NSW

International Nuclear Information System (INIS)

Purss, M.

1998-01-01

Aeromagnetic and airborne radiometric data from the National Geoscience Mapping Accord (courtesy of the Australian Geological Survey Organisation and the New South Wales Department of Mineral Resources) for the southern portion of the Mudgee 1:100,000 Sheet, together with gravity data from the Australian National Gravity Database (courtesy of the Australian Geological Survey Organisation) were interpreted to aid in solving geological problems highlighted by previous studies of the Aarons Pass Granite. Of these, the western margin of the granite (postulated as being fault related) and an unusual radiometric anomaly were the main focuses of study. Interpretation of the aeromagnetic and airborne radiometric data involved the application of numerous filters and image display formats in order to identify spatial correlation's within and between the respective data. The aeromagnetic, or total magnetic intensity (TMI), data were represented as pseudocolour and intensity layers, with a directional sun-angle illumination algorithm applied to the intensity layer. 'High pass' and 'upward continuation' filters were also applied to the data. The airborne radiometric data were examined by various means. Firstly, each of the potassium, thorium, and uranium bands were normalised against the total counts band and represented as pseudocolour layers draped over sun-angle illuminated intensity layers. Secondly, in the standard potassium, thorium, and uranium (Red, Green, Blue) ternary image format, as a flat RGB image and an RGB image draped over a sun-angle illuminated high pass filtered TMI layer. And thirdly, as a K/Th ratio image in pseudocolour draped over a sun-angle illuminated intensity layer. Although the gravity data were not collected by airborne means it nonetheless proved useful in highlighting important spatial information relating to the western margin of the granite which was obscured by the nature of the aeromagnetic data. As a result, the image analysis of this data

Assessment of long-range kinematic GPS positioning errors by comparison with airborne laser altimetry and satellite altimetry

DEFF Research Database (Denmark)

Zhang, X.H.; Forsberg, René

2007-01-01

Long-range airborne laser altimetry and laser scanning (LIDAR) or airborne gravity surveys in, for example, polar or oceanic areas require airborne kinematic GPS baselines of many hundreds of kilometers in length. In such instances, with the complications of ionospheric biases, it can be a real...... challenge for traditional differential kinematic GPS software to obtain reasonable solutions. In this paper, we will describe attempts to validate an implementation of the precise point positioning (PPP) technique on an aircraft without the use of a local GPS reference station. We will compare PPP solutions...... of the Arctic Ocean north of Greenland, near-coincident in time and space with the ICESat satellite laser altimeter. Both of these flights were more than 800 km long. Comparisons between different GPS methods and four different software packages do not suggest a clear preference for any one, with the heights...

Hardware Design for a Fixed-Wing Airborne Gravity Measurement System

Science.gov (United States)

1986-12-22

worldwide navigation system currently available that is sufficiently accurate for deter- mining Eotvos correction in airborne gravimetry is the Global...better in defining the strength of precipitation . The radar display is compact enough to be mounted on the cockpit, thus giving the pilots better...of the proposed AGMS version 3 MISCELLANEOUS AIRCRAFT CONSIDERATIONS Autopilot One of the most important considerations in airborne gravimetry is

Borehole Gravity Meter Surveys at the Waste Treatment Plant, Hanford, Washington.

Energy Technology Data Exchange (ETDEWEB)

MacQueen, Jeffrey D.; Mann, Ethan

2007-04-06

Microg-LaCoste (MGL) was contracted by Pacfic Northwest National Laboratories (PNNL) to record borehole gravity density data in 3 wells at the HanfordWaste Treatment Plant (WTP) site. The survey was designed to provide highly accurate density information for use in seismic modeling. The borehole gravity meter (BHGM) tool has a very large depth of investigation (hundreds of feet) compared to other density tools so it is not influenced by casing or near welbore effects, such as washouts.

3. Neural changes in different gravity and ecophysiological environments - A survey

Science.gov (United States)

Slenzka, K.

Neural changes or neuronal plasticity occur after and during different stimulations and inputs in general. Gravity is one major input to the brain transferred from the vestibular system. However, often also direct effects of gravity on the cellular level are discussed. Our group was investigating the influence of different gravity environments on a large variety of neuronal enzymes in the developing fish brain. Long-term space travel or bases on Moon and Mars will have to deal not only with neural changes based on the different gravity environment, but also with potential negative or even toxic changes in the respective life support system. Our goal is now to identify reported enzyme activity changes in the brain based for example on potential toxic drugs or endocrine disruptors in combination with gravity induced changes. In this paper a survey will be undertaken discussing recent results obtained in ecotoxicology, gravitational biology combined with new data from our group regarding potential differences in brain glucose-6-phosphate dehydrogenase of medaka and zebrafish.

Field experiment for investigation of very shallow basement structure by micro-gravity survey; Microgravity tansa no gokusenbu kiban chosa eno tekiyo jikken

Energy Technology Data Exchange (ETDEWEB)

Oshita, K; Nozaki, K [OYO Corp., Tokyo (Japan)

1997-10-22

This paper illustrates the field experiment results in which micro-gravity survey was applied to investigation of very shallow basement structure between a few m and 10 m. Its applicability was discussed. In principle, the micro-gravity survey was conducted at the measuring points in a grid with 20 m pitch. Measuring points of 174 were used. The gravity system used for the measurements is an automatic gravimeter CG-3M made by the Scintrex. Survey results of P-wave reflection method conducted at the site using a vibrator focus were used as control data of micro-gravity survey. Consequently, change in the thickness of surface layer (earth filling) shallower than the depth of -10 m could be grasped as a plane. It was found that the micro-gravity survey is a useful method for the investigation of very shallow basement structure. Survey results by the reflection method could contribute to the determination of trend face at filtration and construction of density model as well as the geologic interpretation of gravity anomaly. As a result, reliability of micro-gravity survey and reflection method could be enhanced, mutually. 3 refs., 8 figs.

Synoptic view of the different domains of application of airborne radiometric and spectrometric surveys in egypt

International Nuclear Information System (INIS)

Fouad, K.M.

1998-01-01

Airborne radiometric survey has been applied for more than three decades in egypt. Experience gained from the acquired data over different geological environments has revealed the importance of this geophysical tool in: 1. disclosure of anomalies of potential uranium deposits, 2. geological mapping, 3. environmental monitoring of natural radiometric background around nuclear facilities, as well as the detection of nuclear fallout resulting from local or foreign nuclear activities. The advent of recording of the discriminated gamma ray energies in the airborne 256-channel spectrometer has eventually resulted in the quantitative detection of uranium, thorium, and potassium and their elemental ratios in the rocks. This has greatly widened the scope of geophysical and geochemical application. When this type is coupled with airborne magnetometry, the geological and structural configuration is appreciably revealed in three dimensions. The important role played by the statistical method of analysis is also shown. Case histories from the eastern desert, and sinai peninsula, are exhibited to help manifest the wide variety of applications of radiometric and spectrometric surveys

Improved sampling for airborne surveys to estimate wildlife population parameters in the African Savannah

NARCIS (Netherlands)

Khaemba, W.; Stein, A.

2002-01-01

Parameter estimates, obtained from airborne surveys of wildlife populations, often have large bias and large standard errors. Sampling error is one of the major causes of this imprecision and the occurrence of many animals in herds violates the common assumptions in traditional sampling designs like

Data reduction and tying in regional gravity surveys—results from a new gravity base station network and the Bouguer gravity anomaly map for northeastern Mexico

Science.gov (United States)

Hurtado-Cardador, Manuel; Urrutia-Fucugauchi, Jaime

2006-12-01

Since 1947 Petroleos Mexicanos (Pemex) has conducted oil exploration projects using potential field methods. Geophysical exploration companies under contracts with Pemex carried out gravity anomaly surveys that were referred to different floating data. Each survey comprises observations of gravity stations along highways, roads and trails at intervals of about 500 m. At present, 265 separate gravimeter surveys that cover 60% of the Mexican territory (mainly in the oil producing regions of Mexico) are available. This gravity database represents the largest, highest spatial resolution information, and consequently has been used in the geophysical data compilations for the Mexico and North America gravity anomaly maps. Regional integration of gravimeter surveys generates gradients and spurious anomalies in the Bouguer anomaly maps at the boundaries of the connected surveys due to the different gravity base stations utilized. The main objective of this study is to refer all gravimeter surveys from Pemex to a single new first-order gravity base station network, in order to eliminate problems of gradients and spurious anomalies. A second objective is to establish a network of permanent gravity base stations (BGP), referred to a single base from the World Gravity System. Four regional loops of BGP covering eight States of Mexico were established to support the tie of local gravity base stations from each of the gravimeter surveys located in the vicinity of these loops. The third objective is to add the gravity constants, measured and calculated, for each of the 265 gravimeter surveys to their corresponding files in the Pemex and Instituto Mexicano del Petroleo database. The gravity base used as the common datum is the station SILAG 9135-49 (Latin American System of Gravity) located in the National Observatory of Tacubaya in Mexico City. We present the results of the installation of a new gravity base network in northeastern Mexico, reference of the 43 gravimeter surveys

Study on temperature field airborne remote sensing survey along shore nuclear power station in different tide status

International Nuclear Information System (INIS)

Liang Chunli; Li Mingsong

2010-01-01

Nuclear Power Station needs to let large quantity of cooling water to the near sea area when it is running. Whether the cooling water has effect to surrounding environment and the running of Nuclear Power Station needs further research. Temperature Drainage Mathematic Model and Physical Analogue Model need to acquire the distribution characteristic of near Station sea surface temperature field in different seasons and different tide status. Airborne Remote Sending Technique has a advantage in gaining high resolution sea surface temperature in different tide status, and any other manual method with discrete point survey can not reach it. After a successful implementation of airborne remote sensing survey to gain the near-shore temperature drainage information in Qinshan Nuclear Power Station, it provides the reference methods and ideas for temperature drainage remote sensing survey of Nuclear Power Station. (authors)

Prognoses of prospective areas for uranium metallogenesis with full-spectrum information of airborne gamma-ray survey

International Nuclear Information System (INIS)

Hu Mingkao; Shen Zhengxin; Li Binghai; Cai Genqing

2010-01-01

This paper briefly introduces the development of airborne radioactive survey and the background of carrying out full-spectrum study. It also introduces the method, standard and application example of using the full-spectrum information of airborne gamma spectrum to predict U-metallogenic prospective areas. The field checking has found that uranium in the water of the prospective area is three magnitude higher than that in the normal area. The developmment and the application of this method will play a multiplier role in reusing the library stored data evaluating uranium resource potential in our Country. (authors)

The role of satellite altimetry in gravity field modelling in coastal areas

DEFF Research Database (Denmark)

Andersen, Ole Baltazar; Knudsen, Per

2000-01-01

global uniform gravity information with very high resolution, and these global marine gravity fields are registered on a two by two minute grid corresponding to 4 by 4 kilometres at the equator. In this presentation several coastal complications in deriving the marine gravity field from satellite...... altimetry will be investigated using the KMS98 gravity field. Comparison with other sources of gravity field information like airborne and marine gravity observations will be carried out and two fundamentally different test areas (Azores and Skagerak) will be studied to investigated the different role...

Evaluation and comparison of the processing methods of airborne gravimetry concerning the errors effects on downward continuation results: Case studies in Louisiana (USA) and the Tibetan Plateau (China)

DEFF Research Database (Denmark)

Zhao, Qilong; Strykowski, Gabriel; Li, Jiancheng

2017-01-01

and the most extreme area of the world for this type of survey is the Tibetan Plateau. Since there are no high-accuracy surface gravity data available for this area, the above error minimization method involving the external gravity data cannot be used. We propose a semi-parametric downward continuation method...... in combination with regularization to suppress the systematic error effect and the random error effect in the Tibetan Plateau; i.e., without the use of the external high-accuracy gravity data. We use a Louisiana airborne gravity dataset from the USA National Oceanic and Atmospheric Administration (NOAA......) to demonstrate that the new method works effectively. Furthermore, and for the Tibetan Plateau we show that the numerical experiment is also successfully conducted using the synthetic Earth Gravitational Model 2008 (EGM08)-derived gravity data contaminated with the synthetic errors. The estimated systematic...

Airborne gamma survey of the historic Sleisbeck mine area in the Northern Territory, Australia, and its use for site rehabilitation planning

International Nuclear Information System (INIS)

Bollhoefer, A.; Pfitzner, K.; Ryan, B.; Martin, P.; Fawcett, M.; Jones, D.R.

2008-01-01

An airborne γ-survey provided information about the extent of radioactive contamination around the historic Sleisbeck mine. Quickbird satellite data were acquired to relate airborne measurements to land cover features. Enhanced equivalent uranium (eU) levels were found to be confined to the mine and low grade waste rock dumps. The average terrestrial background radiation dose rate estimated from the airborne gamma survey data was 0.10-0.14 μGy h -1 while the area around the mine exhibited a maximum of ∼2.3 μGy h -1 , but measurements on the ground indicate that this maximum is exceeded in some localized areas. Rehabilitation of the site is likely to result in a threefold reduction in radiation doses to people accessing the area

SURVEY OF CULTURABLE AIRBORNE BACTERIA AT FOUR DIVERSE LOCATIONS IN OREGON: URBAN, RURAL, FOREST, AND COASTAL

Science.gov (United States)

To determine the risks of microbial air pollution from microorganisms used for pesticides and bioremediation, or emanating from composting, fermentation tanks, or other agricultural and urban sources, airborne microbial levels must be evaluated. This study surveyed the atmospheri...

Research on airborne comprehensive survey system of atmosphere quality

International Nuclear Information System (INIS)

Yu Zhentao; Yu Yanbin

1998-01-01

The global atmosphere pollution is becoming more and more serious, affecting the human existence and development. Besides, the high spectrum resolution remote sensing technique, which has been applied to observe topographic features, identify military objectives and distinguish lithology and vegetation, has the relation to atmosphere quality and is influenced by atmosphere pollution (including radon pollution) and dust content in the atmosphere, it is imperative to monitor atmosphere quality. Based upon the selection of some main parameters evaluating atmospheric quality and necessary equipment, the author introduces the design of multiple airborne comprehensive survey system of atmosphere quality and how to deal with problems that crop up during the hardware designing and software programming

Airborne full tensor magnetic gradiometry surveys in the Thuringian basin, Germany

Science.gov (United States)

Queitsch, M.; Schiffler, M.; Goepel, A.; Stolz, R.; Meyer, M.; Meyer, H.; Kukowski, N.

2013-12-01

In this contribution we introduce a newly developed fully operational full tensor magnetic gradiometer (FTMG) instrument based on Superconducting Quantum Interference Devices (SQUIDs) and show example data acquired in 2012 within the framework of the INFLUINS (Integrated Fluid Dynamics in Sedimentary basins) project. This multidisciplinary project aims for a better understanding of movements and interaction between shallow and deep fluids in the Thuringian Basin in the center of Germany. In contrast to mapping total magnetic field intensity (TMI) in conventional airborne magnetic surveys for industrial exploration of mineral deposits and sedimentary basins, our instrument measures all components of the magnetic field gradient tensor using highly sensitive SQUID gradiometers. This significantly constrains the solutions of the inverse problem. Furthermore, information on the ratio between induced and remanent magnetization is obtained. Special care has been taken to reduce motion noise while acquiring data in airborne operation. Therefore, the sensors are mounted in a nonmagnetic and aerodynamically shaped bird made of fiberglas with a high drag tail which stabilizes the bird even at low velocities. The system is towed by a helicopter and kept at 30m above ground during data acquisition. Additionally, the system in the bird incorporates an inertial unit for geo-referencing and enhanced motion noise compensation, a radar altimeter for topographic correction and a GPS system for high precision positioning. Advanced data processing techniques using reference magnetometer and inertial unit data result in a very low system noise of less than 60 pT/m peak to peak in airborne operation. To show the performance of the system we present example results from survey areas within the Thuringian basin and along its bordering highlands. The mapped gradient tensor components show a high correlation to existing geologic maps. Furthermore, the measured gradient components indicate

Gravity changes in mid-west Greenland from GOCE gravity model and gradient data using ground and airborne gravity

DEFF Research Database (Denmark)

Tscherning, Carl Christian; Herceg, Matija; Fredenslund Levinsen, Joanna

GOCE TRF (terrestrial reference frame) vertical anomalous gradients (Tzz) from two periods have been used to determine gravity anomalies changes in mid-west Greenland, where a large mass-loss has been detected using GRACE (Fig. 1). As additional data were used the GOCE DIR-3 model and ground...... gravity at the coast on solid rock, where no mass loss is expected. The methods of Least-Squares Collocation (LSC) and the Reduced Point Mass (RPM) methods have been used, however only LSC included the ground data....

An interpretation of the 1997 airborne electromagnetic (AEM) survey, Fort Huachuca vicinity, Cochise County, Arizona

Science.gov (United States)

Bultman, M.W.; Gettings, M.E.; Wynn, Jeff

1999-01-01

Executive Summary -- In March of 1997, an airborne electromagnetic (AEM) survey of the Fort Huachuca Military Reservation and immediate surrounds (location map, http://geopubs.wr.usgs.gov/open-file/of99-007-b/index.jpg) was conducted. This survey was sponsored by the U.S. Army and contracted through the Geologic Division of the U.S. Geological Survey (USGS). Data were gathered by Geoterrex-Dighem Ltd. of Ottawa, Canada. The survey aircraft is surrounded by a coil through which a large current pulse is passed. This pulse induces currents in the Earth which are recorded by a set of three mutually perpendicular coils towed in a 'bird' about 100 m behind and below the aircraft. The bird also records the Earth's magnetic field. The system samples the Earth response to the electromagnetic pulse about every 16 m along the aircraft flight path. For this survey, the bulk of the flightpaths were spaced about 400 m apart and oriented in a northeast-southwest direction extending from bedrock over the Huachuca Mountains to bedrock over the Tombstone Hills. A preliminary report on the unprocessed data collected in the field was delivered to the U.S. Army by USGS in July 1997 (USGS Open-File Report 97?457). The final data were delivered in March, 1998 by the contractor to USGS and thence to the U.S. Army. The present report represents the final interpretive report from USGS. The objectives of the survey were to: 1) define the structure of the San Pedro basin in the Sierra Vista-Fort Huachuca-Huachuca City area, including the depth and shape of the basin, and to delineate large faults that may be active within the basin fill and therefore important in the hydrologic regime; 2) define near surface and subsurface areas that contain a large volume fraction of silt and clay in the basin fill and which both reduce the volume of available storage for water and reduce the permeability of the aquifer; and 3) to evaluate the use of the time domain electromagnetic method in the southwest

Gravity gradiometer system for Earth Exploration

NARCIS (Netherlands)

Cuperus, R.; Flokstra, F.F.; Droogendijk, H.; Wiegerink, Remco J.; Flokstra, Jakob; Flokstra, Jan

2009-01-01

We develop a gravity gradiometer (GG) for use on planetary missions to planets like Mars and Jupiter. With some modifications this development is extended to include (airborne) applications for the Dutch exploratory industry. We adapt key technology of the space based GG for the use in an

Optimizing Spectroscopic and Photometric Galaxy Surveys: Same-Sky Benefits for Dark Energy and Modified Gravity

Energy Technology Data Exchange (ETDEWEB)

Kirk, Donnacha [University Coll. London; Lahav, Ofer [University Coll. London; Bridle, Sarah [Manchester U.; Jouvel, Stephanie [Barcelona, IEEC; Abdalla, Filipe B. [University Coll. London; Frieman, Joshua A. [Chicago U., KICP

2015-08-21

The combination of multiple cosmological probes can produce measurements of cosmological parameters much more stringent than those possible with any individual probe. We examine the combination of two highly correlated probes of late-time structure growth: (i) weak gravitational lensing from a survey with photometric redshifts and (ii) galaxy clustering and redshift space distortions from a survey with spectroscopic redshifts. We choose generic survey designs so that our results are applicable to a range of current and future photometric redshift (e.g. KiDS, DES, HSC, Euclid) and spectroscopic redshift (e.g. DESI, 4MOST, Sumire) surveys. Combining the surveys greatly improves their power to measure both dark energy and modified gravity. An independent, non-overlapping combination sees a dark energy figure of merit more than 4 times larger than that produced by either survey alone. The powerful synergies between the surveys are strongest for modified gravity, where their constraints are orthogonal, producing a non-overlapping joint figure of merit nearly 2 orders of magnitude larger than either alone. Our projected angular power spectrum formalism makes it easy to model the cross-correlation observable when the surveys overlap on the sky, producing a joint data vector and full covariance matrix. We calculate a same-sky improvement factor, from the inclusion of these cross-correlations, relative to non-overlapping surveys. We find nearly a factor of 4 for dark energy and more than a factor of 2 for modified gravity. The exact forecast figures of merit and same-sky benefits can be radically affected by a range of forecasts assumption, which we explore methodically in a sensitivity analysis. We show that that our fiducial assumptions produce robust results which give a good average picture of the science return from combining photometric and spectroscopic surveys.

Analysis of airborne LiDAR surveys to quantify the characteristic morphologies of northern forested wetlands

Science.gov (United States)

Murray C. Richardson; Carl P. J. Mitchell; Brian A. Branfireun; Randall K. Kolka

2010-01-01

A new technique for quantifying the geomorphic form of northern forested wetlands from airborne LiDAR surveys is introduced, demonstrating the unprecedented ability to characterize the geomorphic form of northern forested wetlands using high-resolution digital topography. Two quantitative indices are presented, including the lagg width index (LWI) which objectively...

ELABORATION OF THE 3D MODEL AND SURVEY OF THE POWER LINES USING DATA FROM AIRBORNE LASER SCANNING

Directory of Open Access Journals (Sweden)

Bogusława Kwoczyńska

2016-09-01

Full Text Available One of the methods of obtaining highly accurate and current spatial data about the terrain, as well as objects situated on it, is laser scanning. LIDAR (Light Detection and Ranging is among the most modern, dynamically developing technologies and reveals in surveying new capabilities that have been unachievable in a traditional way so far. The aim of the publication is to show the possibilities of using data from airborne laser scanning to perform the survey and visualization of the energy network, and also identification of hazards which the present network constitutes for the immediate environment using the TerraSolid software package. The survey was conducted for two independent sections of the power line, on the basis of two different clouds of points obtained from the airborne laser scanning. The first one had a density of 16 points/m2, while the other 22 pts/m2. The project was created in an environment of MicroStation V8i software using special overlays – TerraScan and TerraModeler of Finnish TerraSolid Company. The use of the test clouds of different densities was intended to indicate an optimal density of the cloud of points, which allows carrying out a survey and visualization of the energy network based on data derived from airborne laser scanning. The publication presents on particular examples the procedure of vectorization and visualization of the power line and detection of objects within a dangerous distance from it. The possibility of using applied LIDAR data, meeting the industry requirements, to the survey of power lines has been also confirmed.

Arctic Ocean gravity, geoid and sea-ice freeboard heights from ICESat and GRACE

DEFF Research Database (Denmark)

Forsberg, René; Skourup, Henriette

2005-01-01

Gravity Project in combination with GRACE gravity field models to derive an improved Arctic geoid model. This model is then used to convert ICESat measurements to sea-ice freeboard heights with a coarse lowest-level surface method. The derived freeboard heights show a good qualitative agreement...... all major tectonic features of the Arctic Ocean, and has an accuracy of 6 mGal compared to recent airborne gravity data, illustrating the usefulness of ICESat data for gravity field determination....

Regional-scale airborne electromagnetic surveying of the Yucatan karst aquifer (Mexico): geological and hydrogeological interpretation

DEFF Research Database (Denmark)

Gondwe, Bibi Ruth Neuman; Ottowitz, David; Supper, Robert

2012-01-01

-spectral remote sensing imagery, shuttle radar topography data and frequency-domain airborne electromagnetic (AEM) survey data were used to map karst-aquifer structure on the Yucatan Peninsula, Mexico. Anomalous AEM responses correlated with topographic features and anomalous spectral reflectance of the terrain...... as ejecta from the Chicxulub impact (Cretaceous/Paleogene boundary), based on similar resistivity signatures found in borehole logs. Due to limited sensitivity of the AEM survey, the subsurface configuration beneath the low-resistivity layer could not be unambiguously determined. AEM measurements combined...

Report on airborne radioactivity surveys and the uranium deposits in the Red River region of Texas and Oklahoma

International Nuclear Information System (INIS)

Blair, R.G.; Stehle, F.T.; Levich, R.A.

1973-11-01

The U. S. Atomic Energy Commission conducted an airborne radioactivity survey of the Red River region of Texas and Oklahoma beginning in December 1955 and ending in May 1956. All or parts of Archer, Clay, and Montague Counties in northern Texas and Carter, Cotton, Jefferson, and Stephens Counties in southern Oklahoma were surveyed. Particular attention was paid to those areas where exposures are found of red beds of the Permian Wichita Group. Field examinations were conducted of anomalies discovered by airborne reconnaissance as well as those reported by private individuals. Forty localities were examined, the majority in sandstones, siltstones, or conglomerates. Uranium and copper minerals were identified at several localities. Ferruginous staining, bleaching of the sandstone color, calcium carbonate cement, and carbonized plant remains are common to the deposits

Advances and perspectives in bathymetry by airborne lidar

Science.gov (United States)

Zhou, Guoqing; Wang, Chenxi; Li, Mingyan; Wang, Yuefeng; Ye, Siqi; Han, Caiyun

2015-12-01

In this paper, the history of the airborne lidar and the development stages of the technology are reviewed. The basic principle of airborne lidar and the method of processing point-cloud data were discussed. At present, single point laser scanning method is widely used in bathymetric survey. Although the method has high ranging accuracy, the data processing and hardware system is too much complicated and expensive. For this reason, this paper present a kind of improved dual-frequency method for bathymetric and sea surface survey, in this method 176 units of 1064nm wavelength laser has been used by push-broom scanning and due to the airborne power limits still use 532nm wavelength single point for bathymetric survey by zigzag scanning. We establish a spatial coordinates for obtaining the WGS-84 of point cloud by using airborne POS system.

PIXE analysis of airborne particulate matter from Monterrey, Mexico. A first survey

International Nuclear Information System (INIS)

Aldape, F.; Flores M, J.; Diaz, R.V.; Hernandez-Mendez, B.; Montoya Z, J.M.; Blanco, E.E.; Fuentes, A.F.; Torres-Martinez, L.M.

1999-01-01

A first survey of elemental contents in airborne particulate matter from Monterrey, Nuevo Leon, Mexico, was performed using PIXE. This second largest industrial city is located 715 km north of Mexico City, and counts with a population of nearly three million inhabitants in its conurbation. Air pollution in the place comes from a great variety of industries ranging from iron smelters to furniture manufacturing, as well as from fuel combustion in vehicles and industries. This study presents results of elemental contents in airborne particulate matter in two particle size fractions: PM 2.5 and PM 15 . The samples were collected during five weeks on working days, Monday-Friday, from 9 December 1996 to 14 January 1997. Two samples a day were collected, 12 h each, night-time and day-time. These first results show local pollution as typical from a large urban area in conjunction with an active industry. Thirteen elements were consistently detected in most of the samples and some episodes due to both industrial and human activities were identified. A general discussion about the results obtained is presented

Regional gravity and magnetic surveys along southern margin of Indravati basin, Central India - a guide to unconformity related uranium mineralisation

International Nuclear Information System (INIS)

Patra, I.; Ramesh Babu, V.; Chaturvedi, A.K.; Sreenivas, R.; Chari, M.N.; Dash, J.K.; Roy, M.K.

2009-01-01

Geophysical methods play vital role at various stages in mineral exploration programme particularly in case of buried deposits. The unconformity related uranium deposits owing to their concealed nature are explored by geophysical methods as an indirect tool. Regional ground gravity and magnetic surveys have been conducted to decipher the basin configuration, presence of fault/ fractures and basic activity. These structural features may form favorable criteria for mineralisation. Qualitative and quantitative interpretation of the gravity and magnetic data along the southern margin of Mesoproterozoic Indravati basin has been correlated with ground follow up geological investigation. There exists a good correlation between interpreted faults, fracture zones and mafic activity from the magnetic and gravity surveys with available borehole data in the area. Further, 2D models generated from magnetic data have paved the way for planning boreholes and thereby reorienting the sub-surface exploration programme. Evidence of alteration and fracturing intercepted from the borehole correlates well with the low gravity and magnetic. Hence, gravity and magnetic surveys can be effectively utilized in delineating basement configuration and to estimate sediment thickness besides deciphering post sedimentary fault/fractures which are favorable factors for unconformity related uranium mineralisation. (author)

The Danish airborne gamma-ray surveying results

Energy Technology Data Exchange (ETDEWEB)

Hovgaard, J. [Danish Emergency Management Agency, Birkeroed (Denmark)

1997-12-31

The Danish Emergency Management Agency (DEMA) in co-operation with the Technical University of Denmark (TUD), Department of Automation, participated in the international exercise RESUME-95 arranged in Finland in August 1995. DEMA performed measurement with their airborne gamma-ray surveying system. Surveys were done in the three areas known as AREA I, II, III. Results from AREA II (3 km x 6 km) show that the apparent {sup 137}Cs deposition assuming a deposition profile equal to the profile in AREA I based on soil samples varies from a few 10th kBqm{sup -2} up to 110 kBqm{sup -2}. However, a detailed analysis using a new method, Noise Adjusted Singular Value Decomposition (NASVD), shows that the true variations probably are smaller and that the observed differences to some extend are due to major variations in the depth distribution of the cesium. For example agricultural areas appears to have cesium much deeper deposit than the undisturbed areas. Another interesting result is that the NASVD analysis shows that the ration of {sup 134}Cs to {sup 137}Cs is fixed and approximately 0.03 (August 1995) a number in good agreement with the expected ratio from the Chernobyl accident. No true real-time software for source detection is yet integrated in the Danish system. Results from AREA III, however, show that the implemented software for rapid post processing of data worked excellent for detection of radioactive sources. Post analysis using NASVD demonstrates that all sources except for a small {sup 137}Cs source can be localized. (au).

The Danish airborne gamma-ray surveying results

Energy Technology Data Exchange (ETDEWEB)

Hovgaard, J [Danish Emergency Management Agency, Birkeroed (Denmark)

1998-12-31

The Danish Emergency Management Agency (DEMA) in co-operation with the Technical University of Denmark (TUD), Department of Automation, participated in the international exercise RESUME-95 arranged in Finland in August 1995. DEMA performed measurement with their airborne gamma-ray surveying system. Surveys were done in the three areas known as AREA I, II, III. Results from AREA II (3 km x 6 km) show that the apparent {sup 137}Cs deposition assuming a deposition profile equal to the profile in AREA I based on soil samples varies from a few 10th kBqm{sup -2} up to 110 kBqm{sup -2}. However, a detailed analysis using a new method, Noise Adjusted Singular Value Decomposition (NASVD), shows that the true variations probably are smaller and that the observed differences to some extend are due to major variations in the depth distribution of the cesium. For example agricultural areas appears to have cesium much deeper deposit than the undisturbed areas. Another interesting result is that the NASVD analysis shows that the ration of {sup 134}Cs to {sup 137}Cs is fixed and approximately 0.03 (August 1995) a number in good agreement with the expected ratio from the Chernobyl accident. No true real-time software for source detection is yet integrated in the Danish system. Results from AREA III, however, show that the implemented software for rapid post processing of data worked excellent for detection of radioactive sources. Post analysis using NASVD demonstrates that all sources except for a small {sup 137}Cs source can be localized. (au).

SGA-WZ: A New Strapdown Airborne Gravimeter

Directory of Open Access Journals (Sweden)

Kaidong Zhang

2012-07-01

Full Text Available Inertial navigation systems and gravimeters are now routinely used to map the regional gravitational quantities from an aircraft with mGal accuracy and a spatial resolution of a few kilometers. However, airborne gravimeter of this kind is limited by the inaccuracy of the inertial sensor performance, the integrated navigation technique and the kinematic acceleration determination. As the GPS technique developed, the vehicle acceleration determination is no longer the limiting factor in airborne gravity due to the cancellation of the common mode acceleration in differential mode. A new airborne gravimeter taking full advantage of the inertial navigation system is described with improved mechanical design, high precision time synchronization, better thermal control and optimized sensor modeling. Apart from the general usage, the Global Positioning System (GPS after differentiation is integrated to the inertial navigation system which provides not only more precise altitude information along with the navigation aiding, but also an effective way to calculate the vehicle acceleration. Design description and test results on the performance of the gyroscopes and accelerations will be emphasized. Analysis and discussion of the airborne field test results are also given.

Impact of CryoSat-2 for marine gravity field - globally and in the Arctic Ocean

DEFF Research Database (Denmark)

Andersen, Ole Baltazar; Stenseng, Lars; Knudsen, Per

GDR data, NOAA LRM data, but also Level1b (LRM, SAR and SAR-in waveforms) data have been analyzed. A suite of eight different empirical retrackers have been developed and investigated for their ability to predict marine gravity in the Arctic Ocean. The impact of the various improvement offered by Cryo...... days repeat offered by CryoSat-2 provides denser coverage than older geodetic mission data set like ERS-1. Thirdly, the 92 degree inclination of CryoSat-2 is designed to map more of the Arctic Ocean than previous altimetric satellites. Finally, CryoSat-2 is able to operate in two new modes (SAR and SAR......Sat-2 in comparison with conventional satellite altimetry have been studied and quantified both globally but particularly for the Arctic Ocean using a large number of marine and airborne surveys providing “ground truth” marine gravity....

Airborne gamma-ray spectrometer and magnetometer survey, Meade River Quadrangle, Alaska. Final report

International Nuclear Information System (INIS)

1981-02-01

The results obtained from an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over the Meade River map area of Alaska are presented. Based on the criteria outlined in the general section on interpretation, a total of eight uranium anomalies have been outlined on the interpretation map. Most of these are only weakly to moderately anomalous. Zones 3 and 7 are relatively better than the others though none of the anomalies are thought to be of any economic significance. No follow-up work is recommended

Airborne gamma-ray spectrometer and magnetometer survey: north/south tieline. Final report

International Nuclear Information System (INIS)

1981-05-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted along the 99 0 longitude meridian from the Canadian border southward to the Mexican border. A total of 1555 line miles of geophysical data were acquired and, subsequently, compiled. The north-south tieline was flown as part of the National Uranium Resources Evaluation. NURE is a program of the US Department of Energy's Grand Junction, Colorado, office to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

Voxel inversion of airborne EM data

DEFF Research Database (Denmark)

Fiandaca, Gianluca G.; Auken, Esben; Christiansen, Anders Vest C A.V.C.

2013-01-01

We present a geophysical inversion algorithm working directly in a voxel grid disconnected from the actual measuring points, which allows for straightforward integration of different data types in joint inversion, for informing geological/hydrogeological models directly and for easier incorporation...... of prior information. Inversion of geophysical data usually refers to a model space being linked to the actual observation points. For airborne surveys the spatial discretization of the model space reflects the flight lines. Often airborne surveys are carried out in areas where other ground......-based geophysical data are available. The model space of geophysical inversions is usually referred to the positions of the measurements, and ground-based model positions do not generally coincide with the airborne model positions. Consequently, a model space based on the measuring points is not well suited...

Airborne gamma-ray spectrometer and magnetometer survey, Sagavanirktok Quadrangle, Alaska. Volume I. Final report

International Nuclear Information System (INIS)

1981-03-01

The results obtained from an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over the Sagavanirktok map area of Alaska are presented. Based on the criteria outlined in the general section on interpretation, a total of eight uranium anomalies have been outlined on the interpretation map. However, all of these zones are only weakly to moderately anomalous. None are thought to be indicative of local enrichment of uranium to economically significant levels. No follow-up work is recommended

Development of an airborne gamma radiation system for snow surveys

Energy Technology Data Exchange (ETDEWEB)

Fritzsche, A E [EG and G, Inc., Las Vegas, NV (USA)

1979-01-01

An airborne gamma-snow survey system requires detailed design to obtain maximum precision and accuracy. The use of NaI(Te) gamma detectors with a full gamma energy spectrum pulse height analyzer together with a small computer provide a self-contained and flexible system. The dual detector method determines atmospheric radon perturbations in the detection system. Detailed calibration experiments must be performed to determine twenty parameters that describe the physical nature of the system. Multiple high altitude and lake flights are used to obtain background components. Simulation pads, loaded with varying concentrations of /sup 40/K, /sup 232/Th and /sup 23/..gamma..U yield photopeak stripping coefficients and basic system sensitivity. Multiple altitude flights over land lines provide air attenuation coefficients which may converted to water attenuation coefficients.

Three-dimensional mapping of salt load in the Murray-Darling Basin, 1 Steps in calibration of airborne electromagnetic surveys

NARCIS (Netherlands)

Cresswell, R.G.; Dent, D.L.; Jones, G.; Galloway, D.

2004-01-01

An airborne electromagnetic survey yields a three-dimensional map of ground electrical conductivity. The remotely sensed data are translated into salt load by field and laboratory calibration: drilling, measurement of borehole conductivity, electrical conductivity of 1 : 5 soil¿water extracts

Manganese survey in airborne particulate matter from a mining area at Hidalgo State, Mexico

International Nuclear Information System (INIS)

Aldape, F.; Hernandez-Mendez, B.; Flores M, J.

1999-01-01

A manganese (Mn) survey in airborne particulate matter from a mining area located in Hidalgo State (Mexico) was performed using PIXE. Deposits of Mn ore, first discovered in 1959 and under continuous exploitation since 1962, are nowadays considered as one of the most important of their kind in the American Continent. Afterwards, local inhabitants have been under continuous overexposure to dusts and water highly enriched with Mn. Since no information was available about Mn content in airborne particulate matter in that area, especially in the respirable fraction PM 2.5 , airborne particles were collected simultaneously at two sites located on opposite sides of the rim of the mining valley, and along the line of prevailing local winds. The sample collection was performed on eight alternate days, taking two samples per day (day-time and night-time) at each sampling site, using Stacked Filter Units (SFUs) of the Davis design to separate particles into fine (PM 2.5 ) and coarse (PM 15 ) sizes. The samples were PIXE analyzed and the results of this study revealed that Mn content, in both fine and coarse fractions, were in excess of the general urban background level of 40 ng/m 3 (US Environmental Protection Agency, 1990) in more than 50% of the samples, which indicate severe environmental deterioration in the place under study

Airborne gamma-ray spectrometer and magnetometer survey. Volume I. Final report

International Nuclear Information System (INIS)

An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Mariposa, California and Nevada; Fresno, California; and Bakersfield, Caifornia 1:250,000 National Topographic Map Series (NTMS) 1 0 x 2 0 quadrangle maps. The survey was a part of DOE's National Aerial Radiometric Reconnaissance (ARR) program, which in turn is a part of the National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured throughout the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. These maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

Three decades of BGR airborne geophysical surveys over the polar regions - a review

Science.gov (United States)

Damaske, Detlef

2013-04-01

The Federal Institute for Geosciences and Natural Resources (BGR) has been conducting geological polar research since 1979. A few years later BGR engaged in airborne geophysical projects. Investigation of the lithosphere of the continent and the continental margins was one of the key issues for BGR. Right from the beginning geophysical research was closely associated with the geological activities. The GANOVEX (German Antarctic North Victoria Land Expedition) program combined geological research with geophysical (mainly airborne) investigations. This proved to be a fruitful approach to many of the open questions regarding the tectonic development of the Ross Sea region. Aeromagnetic surveys evolved into a powerful tool for identifying geological structures and following them underneath the ice covered areas - not accessible to direct geological investigations. To achieve this aim it was essential to lay out these surveys with a relatively closely spaced line separation on the expense of covering large areas at the same time. Nevertheless, over many years of continues research areas of more than a just regional extent could be covered. This was, however, only possible through international collaboration. During the first years, working in the Ross Sea area, the cooperation with the US and Italian programs played a significant role, especially the GITARA (German-Italian Aeromagnetic Research in Antarctica) program has to be mentioned. GEOMAUD (Geoscientific Expedition to Dronning Maud Land) and the German-Australian joint venture PCMEGA (Prince Charles Mountains Expedition of Germany & Australia) expanded research activities to the East Antarctic shield area. In the International Polar Year (IPY), BGR played a leading role in the international project AGAP (Antarctica's GAmburtsev Province) as part of the main topic "Venture into Unknown Regions". AGAP was jointly conducted by the USA, Great Britain, Australia, China and Germany. While in the Ross Sea area even

Airborne Magnetic Trackline Database

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) receive airborne magnetic survey data from US and non-US...

Status of the planar electrostatic gradiometer GREMLIT for airborne geodesy

Science.gov (United States)

Lebat, V.; Foulon, B.; Christophe, B.; Huynh, P. A.; Liorzou, F.; Boulanger, D.

2017-12-01

Taking advantage of technologies, developed by ONERA for the GRACE, GOCE and GRACE FOLLOW-ON space missions, the GREMLIT airborne gravity gradiometer is based of a planar electrostatic gradiometer configuration. The feasibility of the instrument and of its performance was proved by realistic simulations, based on actual data and recorded environmental aircraft perturbations, with performance of about one Eötvös along the two horizontal components of the gravity gradient. The performance of the gradiometer is directly linked to the stabilized platform, controlled by the common mode outputs of the instrument itself, in order to reject the perturbations induced by the airborne environment in the horizontal directions. After the definition of the architecture of the stabilized platform to achieve the global performance of the gradiometer, the platform has been manufactured and integrated. In order to assess the operation of the electrostatic gradiometer on its associated stabilized platform, a one axis prototype has also been built. The poster will emphasize the status of realization and first tests of the instrument and of its stabilized platform.

Global Earth Structure Recovery from State-of-the-art Models of the Earth's Gravity Field and Additional Geophysical Information

NARCIS (Netherlands)

Hamayun, H.

2014-01-01

Currently, a tremendous improvement is observed in the accuracy and spatial resolution of global Earth’s gravity field models. This improvement is achieved due to using various new data, including those from satellite gravimetry missions (CHAMP, GRACE, and GOCE); terrestrial and airborne gravity

Gravity data from the San Pedro River Basin, Cochise County, Arizona

Science.gov (United States)

Kennedy, Jeffrey R.; Winester, Daniel

2011-01-01

The U.S. Geological Survey, Arizona Water Science Center in cooperation with the National Oceanic and Atmospheric Administration, National Geodetic Survey has collected relative and absolute gravity data at 321 stations in the San Pedro River Basin of southeastern Arizona since 2000. Data are of three types: observed gravity values and associated free-air, simple Bouguer, and complete Bouguer anomaly values, useful for subsurface-density modeling; high-precision relative-gravity surveys repeated over time, useful for aquifer-storage-change monitoring; and absolute-gravity values, useful as base stations for relative-gravity surveys and for monitoring gravity change over time. The data are compiled, without interpretation, in three spreadsheet files. Gravity values, GPS locations, and driving directions for absolute-gravity base stations are presented as National Geodetic Survey site descriptions.

A time-lapse gravity survey of the Coso geothermal field, China Lake Naval Air Weapons Station, California

Science.gov (United States)

Phelps, Geoffrey; Cronkite-Ratcliff, Collin; Blake, Kelly

2018-04-19

We have conducted a gravity survey of the Coso geothermal field to continue the time-lapse gravity study of the area initiated in 1991. In this report, we outline a method of processing the gravity data that minimizes the random errors and instrument bias introduced into the data by the Scintrex CG-5 relative gravimeters that were used. After processing, the standard deviation of the data was estimated to be ±13 microGals. These data reveal that the negative gravity anomaly over the Coso geothermal field, centered on gravity station CER1, is continuing to increase in magnitude over time. Preliminary modeling indicates that water-table drawdown at the location of CER1 is between 65 and 326 meters over the last two decades. We note, however, that several assumptions on which the model results depend, such as constant elevation and free-water level over the study period, still require verification.

Surface Gravities for 228 M, L, and T Dwarfs in the NIRSPEC Brown Dwarf Spectroscopic Survey

International Nuclear Information System (INIS)

Martin, Emily C.; Mace, Gregory N.; McLean, Ian S.; Logsdon, Sarah E.; Rice, Emily L.; Kirkpatrick, J. Davy; Burgasser, Adam J.; McGovern, Mark R.; Prato, Lisa

2017-01-01

We combine 131 new medium-resolution ( R ∼ 2000) J -band spectra of M, L, and T dwarfs from the Keck NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS) with 97 previously published BDSS spectra to study surface-gravity-sensitive indices for 228 low-mass stars and brown dwarfs spanning spectral types M5–T9. Specifically, we use an established set of spectral indices to determine surface gravity classifications for all of the M6–L7 objects in our sample by measuring the equivalent widths (EW) of the K i lines at 1.1692, 1.1778, and 1.2529 μ m, and the 1.2 μ m FeH J absorption index. Our results are consistent with previous surface gravity measurements, showing a distinct double peak—at ∼L5 and T5—in K i EW as a function of spectral type. We analyze the K i EWs of 73 objects of known ages and find a linear trend between log(Age) and EW. From this relationship, we assign age ranges to the very low gravity, intermediate gravity, and field gravity designations for spectral types M6–L0. Interestingly, the ages probed by these designations remain broad, change with spectral type, and depend on the gravity-sensitive index used. Gravity designations are useful indicators of the possibility of youth, but current data sets cannot be used to provide a precise age estimate.

Surface Gravities for 228 M, L, and T Dwarfs in the NIRSPEC Brown Dwarf Spectroscopic Survey

Energy Technology Data Exchange (ETDEWEB)

Martin, Emily C.; Mace, Gregory N.; McLean, Ian S.; Logsdon, Sarah E. [Department of Physics and Astronomy, University of California Los Angeles, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); Rice, Emily L. [Department of Engineering Science and Physics, College of Staten Island, 2800 Victory Boulevard, Staten Island, NY 10301 (United States); Kirkpatrick, J. Davy [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Burgasser, Adam J. [Center for Astrophysics and Space Science, University of California San Diego, La Jolla, CA 92093 (United States); McGovern, Mark R. [Math and Sciences Division, Antelope Valley College, 3041 West Avenue K, Lancaster, CA 93536 (United States); Prato, Lisa, E-mail: emartin@astro.ucla.edu [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States)

2017-03-20

We combine 131 new medium-resolution ( R ∼ 2000) J -band spectra of M, L, and T dwarfs from the Keck NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS) with 97 previously published BDSS spectra to study surface-gravity-sensitive indices for 228 low-mass stars and brown dwarfs spanning spectral types M5–T9. Specifically, we use an established set of spectral indices to determine surface gravity classifications for all of the M6–L7 objects in our sample by measuring the equivalent widths (EW) of the K i lines at 1.1692, 1.1778, and 1.2529 μ m, and the 1.2 μ m FeH{sub J} absorption index. Our results are consistent with previous surface gravity measurements, showing a distinct double peak—at ∼L5 and T5—in K i EW as a function of spectral type. We analyze the K i EWs of 73 objects of known ages and find a linear trend between log(Age) and EW. From this relationship, we assign age ranges to the very low gravity, intermediate gravity, and field gravity designations for spectral types M6–L0. Interestingly, the ages probed by these designations remain broad, change with spectral type, and depend on the gravity-sensitive index used. Gravity designations are useful indicators of the possibility of youth, but current data sets cannot be used to provide a precise age estimate.

Idaho State Gravity Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (24,284 records) were compiled by the U. S. Geological Survey. This data base was received on February 23, 1993. Principal gravity...

Fiscal 1997 report on the verification survey of geothermal exploration technology. 2. Development of the reservoir variation survey method (development of the gravity survey method); 1997 nendo chinetsu tansa gijutsu nado kensho chosa. Choryuso hendo tansaho kaihatsu (juryoku tansaho kaihatsu) hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-03-01

Among technology developments such as the reservoir evaluation at initial developmental stage and stabilization/maintenance of power after the start of operation, the fiscal 1997 result was described of the development of the gravity survey method. The paper conducted the installation of gravity measuring points outside the existing monitoring range, introduction of CG-3M gravimeter/GPS measuring system, drilling of ground water level monitoring well, etc. for the setup of a system for new gravity monitoring. Moreover, regular measurement of gravity was made for the first fiscal year, and at the same time the continued observation of ground water level, precipitation, atmospheric pressure, and temperature was started. It is necessary to study the effects on gravity variation such as gravity gradient and tidal correction. Conducted were collection/arrangement of the existing data and database construction for history matching/variation prediction in the Yanaizu Nishiyama area. The paper made surveys of the trends/literature. In the future, needed are the computation using density models of geothermal reservoirs and test use of EDCON`s downhole gravimeter. 44 refs., 30 figs., 17 tabs.

Airborne gamma-ray spectrometer and magnetometer survey, Mitchell Quadrangle, South Dakota. Final report

International Nuclear Information System (INIS)

1981-04-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Mitchell map area. The purpose of this program is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1479 line miles are in this quadrangle

Airborne gamma-ray spectrometer and magnetometer survey: Huron quadrangle, South Dakota. Final report

International Nuclear Information System (INIS)

1981-04-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the Huron map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1459 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

The Future of Gravity

CERN Multimedia

CERN. Geneva

2007-01-01

Of the four fundamental forces, gravity has been studied the longest, yet gravitational physics is one of the most rapidly developing areas of science today. This talk will give a broad brush survey of the past achievements and future prospects of general relativistic gravitational physics. Gravity is a two frontier science being important on both the very largest and smallest length scales considered in contemporary physics. Recent advances and future prospects will be surveyed in precision tests of general relativity, gravitational waves, black holes, cosmology and quantum gravity. The aim will be an overview of a subject that is becoming increasingly integrated with experiment and other branches of physics.

Program software for the automated processing of gravity and magnetic survey data for the Mir computer

Energy Technology Data Exchange (ETDEWEB)

Lyubimov, G.A.

1980-01-01

A presentation is made of the content of program software for the automated processing of gravity and magnetic survey data for the small Mir-1 and Mir-2 computers as worked out on the Voronezh geophysical expedition.

Sea bottom gravity survey of Osaka bay and its study; Osakawan kaitei juryoku chosa to sono kosatsu

Energy Technology Data Exchange (ETDEWEB)

Komazawa, M [Geological Survey of Japan, Tsukuba (Japan); Ota, Y; Shibuya, S; Kumai, M; Murakami, M [Japex Geoscience Institute, Inc., Tokyo (Japan)

1996-05-01

This paper reports a sea bottom gravity survey conducted with an objective to identify deep underground structure in the vicinity of the epicenter of the Hyogoken-Nanbu Earthquake. The surveyed areas are the whole Osaka Bay area north of the north latitude of 34 degrees and 20 minutes, and the eastern part of the Sea of Harima east of the east longitude of 134 degrees and 40 minutes, excluding the areas difficult of performing measurements. A square lattice with sides each about 2 km was arranged with 408 measurement points. The measurement was carried out by using an observation vessel mounted with a sea bottom gravimeter made by LaCoste and Romberg Corporation, which was lowered down to the sea bottom at the measurement points. Errors in positions and water depths at the gravity measuring points were suppressed to less than 0.002 minutes and 0.1 m, respectively. The measurement data were given necessary corrections by using a unified method applicable also to land areas, and a Bouguer anomaly chart was prepared. Based on the chart, this paper summarizes features in the Bouguer anomaly in the surveyed areas (such as the low-gravity anomaly band extending the central part of the Osaka bay from north-east to south-west, and the gradient structure existing on the Awaji island side). 6 refs., 1 fig.

Integration of 3D geological modeling and gravity surveys for geothermal prospection in an Alpine region

Science.gov (United States)

Guglielmetti, L.; Comina, C.; Abdelfettah, Y.; Schill, E.; Mandrone, G.

2013-11-01

Thermal sources are common manifestations of geothermal energy resources in Alpine regions. The up-flow of the fluid is well-known to be often linked to cross-cutting fault zones providing a significant volume of fractures. Since conventional exploration methods are challenging in such areas of high topography and complicated logistics, 3D geological modeling based on structural investigation becomes a useful tool for assessing the overall geology of the investigated sites. Geological modeling alone is, however, less effective if not integrated with deep subsurface investigations that could provide a first order information on geological boundaries and an imaging of geological structures. With this aim, in the present paper the combined use of 3D geological modeling and gravity surveys for geothermal prospection of a hydrothermal area in the western Alps was carried out on two sites located in the Argentera Massif (NW Italy). The geothermal activity of the area is revealed by thermal anomalies with surface evidences, such as hot springs, at temperatures up to 70 °C. Integration of gravity measurements and 3D modeling investigates the potential of this approach in the context of geothermal exploration in Alpine regions where a very complex geological and structural setting is expected. The approach used in the present work is based on the comparison between the observed gravity and the gravity effect of the 3D geological models, in order to enhance local effects related to the geothermal system. It is shown that a correct integration of 3D modeling and detailed geophysical survey could allow a better characterization of geological structures involved in geothermal fluids circulation. Particularly, gravity inversions have successfully delineated the continuity in depth of low density structures, such as faults and fractured bands observed at the surface, and have been of great help in improving the overall geological model.

Airborne geophysical radon hazard mapping

International Nuclear Information System (INIS)

Walker, P.

1993-01-01

Shales containing uranium pose a radon health hazard even when covered by several meters of overburden. Such an alum shale in southern Norway has been mapped with a joint helicopter borne electromagnetic (HEM) and radiometric survey. Results are compared with ground spectrometer, radon emanometer and radon gas measurements in dwellings, and a model to predict radon gas concentrations from the airborne data is developed. Since the shale is conductive, combining the HEM data with the radiometric channel allows the shale to be mapped with greater reliability than if the radiometric channel were used alone. Radiometrically more active areas which do not pose a radon gas hazard can thus be separated from the shales which do. The ground follow-up work consisted of spectrometer and radon emanometer measurements over a uranium anomaly coinciding with a conductor. The correlation between the airborne uranium channel, the ground uranium channel and emanometry is extremely good, indicating that airborne geophysics can, in this case, be used to predict areas having a high radon potential. Contingency tables comparing both radon exhalation and concentration in dwellings with the airborne uranium data show a strong relationship exists between exhalation and the airborne data and while a relationship between concentration and the airborne data is present, but weaker

Airborne gamma-ray spectrometer and magnetometer survey: Aberdeen quadrangle, South Dakota. Final report

International Nuclear Information System (INIS)

1981-04-01

During the months of June through October, 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. This report discusses the results obtained over the Aberdeen, South Dakota map area. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps

DATA ACQUISITION AND APPLICATIONS OF SIDE-LOOKING AIRBORNE RADAR IN THE U. S. GEOLOGICAL SURVEY.

Science.gov (United States)

Jones, John Edwin; Kover, Allan N.

1985-01-01

The Side-Looking Airborne Radar (SLAR) program encompasses a multi-discipline effort involving geologists, hydrologists, engineers, geographers, and cartographers of the U. S. Geological Survey (USGS). Since the program began in 1980, more than 520,000 square miles of aerial coverage of SLAR data in the conterminous United States and Alaska have been acquired or contracted for acquisition. The Geological Survey has supported more than 60 research and applications projects addressing the use of this technology in the earth sciences since 1980. These projects have included preparation of lithographic reproductions of SLAR mosaics, research to improve the cartographic uses of SLAR, research for use of SLAR in assessing earth hazards, and studies using SLAR for energy and mineral exploration through improved geologic mapping.

Airborne gamma-ray spectrometer and magnetometer survey, Point Lay Quadrangle, Alaska. Volume I. Final report

International Nuclear Information System (INIS)

1981-02-01

The results obtained from an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over the Point Lay map area of Alaska are presented. Based on the criteria outlined in the general section on interpretation, a total of six uranium anomalies have been indicated on the interpretation map. All six are only weakly to moderately anomalous in either uranium or the uranium ratios. None of these are thought to be of any economic significance. No follow-up work is recommended for the Point Lay Quadrangle

Airborne gamma-ray spectrometer and magnetometer survey: Harrison Bay Quadrangle, Alaska. Final report, Volume 1

International Nuclear Information System (INIS)

1981-02-01

During the months of July and August of 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 3 0 x 1 0 and one (1) 4 0 x 1 0 NTMS quadrangles of the Alaska North Slope. These include the Barrow, Wainwright, Meade River, Teshekpuk, Harrison Bay, Beechey Point, Point Lay, Utukok River, Lookout Ridge, Ikpikpuk River, Umiat, and Sagavanirktok quadrangles. This report discusses the results obtained over the Harrison Bay map area

Airborne gamma-ray spectrometer and magnetometer survey Coos Bay, Oregon. Final report

International Nuclear Information System (INIS)

1981-05-01

During the months of August, September, and October of 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over ten (10) areas over northern California and southwestern Oregon. These include the 2 0 x 1 0 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1 0 x 2 0 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Coos Bay, Oregon, map area. Line spacing was generally six miles for east/west traverses and eighteen miles for north/south tie lines over the northern one-half of the area. Traverses and tie lines were flown at three miles and twelve miles respectively over the southern one-half of the area. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 863.8 line miles are in this quadrangle

Airborne gamma-ray spectrometer and magnetometer survey: Alturas quadrangle, California. Final report

International Nuclear Information System (INIS)

1981-05-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2 0 x 1 0 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1 0 x 2 0 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Alturas, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1631.6 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

Airborne gamma-ray spectrometer and magnetometer survey: Susanville quadrangle, California. Final report

International Nuclear Information System (INIS)

1981-05-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten (10) areas over northern California and southwestern Oregon. These include the 2 0 x 1 0 NTMS quadrangles of Roseburg, Medford, Weed, Alturas, Redding, Susanville, Ukiah, and Chico along with the 1 0 x 2 0 areas of the Coos Bay quadrangle and the Crescent City/Eureka areas combined. This report discusses the results obtained over the Susanville, California, map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately eighteen (18) miles apart. A total of 16,880.5 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1642.8 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

Airborne campaigns for CryoSat pre-launch calibration and validation

DEFF Research Database (Denmark)

Hvidegaard, Sine Munk; Forsberg, René; Skourup, Henriette

2010-01-01

From 2003 to 2008 DTU Space together with ESA and several international partners carried out airborne and ground field campaigns in preparation for CryoSat validation; called CryoVEx: CryoSat Validation Experiments covering the main ice caps in Greenland, Canada and Svalbard and sea ice in the Ar......From 2003 to 2008 DTU Space together with ESA and several international partners carried out airborne and ground field campaigns in preparation for CryoSat validation; called CryoVEx: CryoSat Validation Experiments covering the main ice caps in Greenland, Canada and Svalbard and sea ice...... in the Arctic Ocean. The main goal of the airborne surveys was to acquire coincident scanning laser and CryoSat type radar elevation measurements of the surface; either sea ice or land ice. Selected lines have been surveyed along with detailed mapping of validation sites coordinated with insitu field work...... and helicopter electromagnetic surveying. This paper summarises the pre-launch campaigns and presents some of the result from the coincident measurement from airborne and ground observations....

Determination of data correction coefficients and the sensitivities of the KIER air-borne gamma-ray spectrometer survey system

International Nuclear Information System (INIS)

Koo, J.H.; Cho, D.H.; Park, Y.S.

1982-01-01

In air-borne gamma-ray spectrometer survey, the observed data must be corrected for the background, Compton scattering and flight altitude. And the corrected data are usually converted into the radiometric elements equivalents of the ground, using the sensitivities of the survey system. Accordingly, the correction coefficients and the sensitivities are determined as follows for the KIER air-borne survey system. The stripping or Compton scattering coefficients α, β and γ at the ground level were first determined on the basis of the gamma-ray count rates due to the 5 concrete calibration pads of the Soosaek Airbase, together with the radiometric elements concentrations of the core samples taken from the pads. As for the determination of the exponential altitude coefficients anti μ(K), anti μ(U), anti μ(Th) and anti μ(Tc), the count rates observed over the Hongseong Test Strip of about 3 km length were used after they had been corrected for the background and Compton scattering. The background count rates mainly caused by the air-craft as well as cosmic radiations were determined with the data taken over the West Sea near Anmyon Island, Chung-cheongnam-do. And the corrected count rates observed over the Strip, combined with the average radiometric elements concentrations of the Strip, yielded the sensitivities k(K), k(U) and k(Th) at the 400 feet flight altitude. (author)

World Gravity Map: a set of global complete spherical Bouguer and isostatic anomaly maps and grids

Science.gov (United States)

Bonvalot, S.; Balmino, G.; Briais, A.; Kuhn, M.; Peyrefitte, A.; Vales, N.; Biancale, R.; Gabalda, G.; Reinquin, F.

2012-04-01

Intelligence Agency (NGA) (Pavlis et al., 2008) and the DTU10 (Andersen, 2010) who represents the best up-to-date global gravity models (including surface gravity measurements from land, marine and airborne surveys as well as gravity and altimetry satellite measurements). The surface free-air anomaly is computed at the Earth's surface in the context of Molodensky theory and includes corrections from the mass of the atmosphere. The way gravity anomalies are computed on a worldwide basis slightly differs from the classical usage, but meets modern concerns which tend to take into account of the real Earth. The resulting anomaly maps and grids will be distributed for scientific and education purposes by the Commission for the Geological Map of the World (CGMW) (http://ccgm.free.fr) and by the Bureau Gravimetrique International (BGI) (http://bgi.omp.obs-mip.fr). Upgraded versions might be done as soon as new global gravity model will be available (including satellite GOCE data for instance). Institutions who are interested to contribute with new datasets of surface gravity measurements (i.e. ground, marine or airborne gravity data) are also invited to contact BGI bgi@cnes.fr.

Contouring algorithm for two dimensional data- an application to airborne surveys

International Nuclear Information System (INIS)

Suryakumar, N.V.; Rohatgi, Savita; Raghuwanshi, S.S.

1994-01-01

The paper describes in general the contouring algorithm for two dimensional projection of aeroradiometric data and considers not only irregularly spaced flight lines but also solves the other problems related to voluminous data acquired during the airborne surveys. Several simple logics have been described for drawing the contours using scan method and taking care of annotations, identification marking, geographical locations, map size, contour density for visual distinctness and many such problems which may arise during contouring. The present paper also discusses various possibilities of contour line segments in the mini-grid and the criterion for selection of suitable segments has been described in detail. A novel approach to avoid the crossing of contours or missing data is also briefly discussed. The simplicity of the algorithm is mentioned for its ready implementation or any computer/plotter. (author). 8 refs., 8 figs

Testing modified gravity at large distances with the HI Nearby Galaxy Survey's rotation curves

Science.gov (United States)

Mastache, Jorge; Cervantes-Cota, Jorge L.; de la Macorra, Axel

2013-03-01

Recently a new—quantum motivated—theory of gravity has been proposed that modifies the standard Newtonian potential at large distances when spherical symmetry is considered. Accordingly, Newtonian gravity is altered by adding an extra Rindler acceleration term that has to be phenomenologically determined. Here we consider a standard and a power-law generalization of the Rindler modified Newtonian potential. The new terms in the gravitational potential are hypothesized to play the role of dark matter in galaxies. Our galactic model includes the mass of the integrated gas, and stars for which we consider three stellar mass functions (Kroupa, diet-Salpeter, and free mass model). We test this idea by fitting rotation curves of seventeen low surface brightness galaxies from the HI Nearby Galaxy Survey (THINGS). We find that the Rindler parameters do not perform a suitable fit to the rotation curves in comparison to standard dark matter profiles (Navarro-Frenk-White and Burkert) and, in addition, the computed parameters of the Rindler gravity show a high spread, posing the model as a nonacceptable alternative to dark matter.

Feasibility study for an airborne high-sensitivity gamma-ray survey of Alaska. Phase II (final) report: 1976--1979 program

International Nuclear Information System (INIS)

1975-01-01

This study constitutes a determination of the extent to which it is feasible to use airborne, high-sensitivity gamma spectrometer systems for uranium reconnaissance in the State of Alaska, and specification of a preliminary plan for surveying the entire state of the 1975--1979 time frame. Phase I included the design of a program to survey the highest priority areas in 1975 using available aircraft and spectrometer equipment. This has now resulted in a contract for 10,305 flight line miles to cover about 11 of the 1:250,000 scale quadrangles using a DC-3 aircraft with an average 6.25 x 25 mile grid of flight line. Phase II includes the design of alternative programs to cover the remaining 128 quadrangles using either a DC-3 and a Bell 205A helicopter or a Helio Stallion STOL aircraft and a Bell 205A helicopter during 1976-1979. The 1976-1979 time frame allows some time for possible new system developments in both airborne gamma-ray spectrometers and in ancillary equipment, and these are outlined. (auth)

Superconducting gravity gradiometer for sensitive gravity measurements. I. Theory

International Nuclear Information System (INIS)

Chan, H.A.; Paik, H.J.

1987-01-01

Because of the equivalence principle, a global measurement is necessary to distinguish gravity from acceleration of the reference frame. A gravity gradiometer is therefore an essential instrument needed for precision tests of gravity laws and for applications in gravity survey and inertial navigation. Superconductivity and SQUID (superconducting quantum interference device) technology can be used to obtain a gravity gradiometer with very high sensitivity and stability. A superconducting gravity gradiometer has been developed for a null test of the gravitational inverse-square law and space-borne geodesy. Here we present a complete theoretical model of this instrument. Starting from dynamical equations for the device, we derive transfer functions, a common mode rejection characteristic, and an error model of the superconducting instrument. Since a gradiometer must detect a very weak differential gravity signal in the midst of large platform accelerations and other environmental disturbances, the scale factor and common mode rejection stability of the instrument are extremely important in addition to its immunity to temperature and electromagnetic fluctuations. We show how flux quantization, the Meissner effect, and properties of liquid helium can be utilized to meet these challenges

Seasonal gravity change at Yellowstone caldera

Science.gov (United States)

Poland, M. P.; de Zeeuw-van Dalfsen, E.

2017-12-01

The driving forces behind Yellowstone's dynamic deformation, vigorous hydrothermal system, and abundant seismicity are usually ascribed to "magmatic fluids," which could refer to magma, water, volatiles, or some combination. Deformation data alone cannot distinguish the relative importance of these fluids. Gravity measurements, however, provide an indication of mass change over time and, when combined with surface displacements, can constrain the density of subsurface fluids. Unfortunately, several decades of gravity surveys at Yellowstone have yielded ambiguous results. We suspect that the difficulty in interpreting Yellowstone gravity data is due to seasonal variations in environmental conditions—especially surface and ground water. Yellowstone gravity surveys are usually carried out at the same time of year (generally late summer) to minimize the impact of seasonality. Nevertheless, surface and subsurface water levels are not likely to be constant from year to year, given annual differences in precipitation. To assess the overall magnitude of seasonal gravity changes, we conducted gravity surveys of benchmarks in and around Yellowstone caldera in May, July, August, and October 2017. Our goal was to characterize seasonal variations due to snow melt/accumulation, changes in river and lake levels, changes in groundwater levels, and changes in hydrothermal activity. We also hope to identify sites that show little variation in gravity over the course of the 2017 surveys, as these locations may be less prone to seasonal changes and more likely to detect small variations due to magmatic processes. Preliminary examination of data collected in May and July 2017 emphasizes the importance of site location relative to sources of water. For example, a site on the banks of the Yellowstone River showed a gravity increase of several hundred microgals associated with a 50 cm increase in the river level. A high-altitude site far from rivers and lakes, in contrast, showed a

Airborne gamma-ray spectrometer and magnetometer survey, New Rockford Quadrangle, North Dakota. Final report

International Nuclear Information System (INIS)

1981-04-01

An airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. The quadrangles located within the North and South Dakota survey area include Devil's Lake, New Rockford, Jamestown, Aberdeen, Huron, Mitchell, and Sioux Falls. This report discusses the results obtained over the New Rockford map area. Traverse lines were flown in an east-west direction at a line spacing of six (6) miles. Tie lines were flown north-south approximately twenty-four (24) miles apart. A total of 21,481 line miles of geophysical data were acquired, compiled, and interpreted during the survey, of which 1397 line miles are in this quadrangle. The purpose of this study is to acquire and compile geologic and other information with which to assess the magnitude and distribution of uranium resources and to determine areas favorable for the occurrence of uranium in the United States

High-resolution gravity and seismic-refraction surveys of the Smoke Tree Wash area, Joshua Tree National Park, California

Science.gov (United States)

Langenheim, Victoria E.; Rymer, Michael J.; Catchings, Rufus D.; Goldman, Mark R.; Watt, Janet T.; Powell, Robert E.; Matti, Jonathan C.

2016-03-02

We describe high-resolution gravity and seismic refraction surveys acquired to determine the thickness of valley-fill deposits and to delineate geologic structures that might influence groundwater flow beneath the Smoke Tree Wash area in Joshua Tree National Park. These surveys identified a sedimentary basin that is fault-controlled. A profile across the Smoke Tree Wash fault zone reveals low gravity values and seismic velocities that coincide with a mapped strand of the Smoke Tree Wash fault. Modeling of the gravity data reveals a basin about 2–2.5 km long and 1 km wide that is roughly centered on this mapped strand, and bounded by inferred faults. According to the gravity model the deepest part of the basin is about 270 m, but this area coincides with low velocities that are not characteristic of typical basement complex rocks. Most likely, the density contrast assumed in the inversion is too high or the uncharacteristically low velocities represent highly fractured or weathered basement rocks, or both. A longer seismic profile extending onto basement outcrops would help differentiate which scenario is more accurate. The seismic velocities also determine the depth to water table along the profile to be about 40–60 m, consistent with water levels measured in water wells near the northern end of the profile.

Airborne systems for emergency radiological monitoring

International Nuclear Information System (INIS)

Jupiter, C.; Boyns, P.

1976-01-01

A variety of aerial radiological monitoring systems are available to respond to a radiological accident or incident affecting large areas. These are operated by EG and G, Inc. for ERDA's Division of Operational Safety. A survey system can be airborne within approximately two hours after notification. Both airborne and terrestrial radioactivity can be measured and mapped. Special analysis procedures allow discrimination between radioactivity from most man-made radioelements and naturally occurring radioelements. A position accuracy of +-54 feet can be maintained over a large area survey. Detection sensitivity for gamma sources employing NaI detector arrays on board an airplane flying at 500 feet altitude is better than 2 μR/hr for surface planar contaminants and approximately 10 mCi for a point gamma source

Airborne Gamma-Ray Survey in Latvia 1995/96

DEFF Research Database (Denmark)

Bargholz, Kim

1998-01-01

Based on Airborne Gamma-Ray Spectrometry measurements performed with the Danish AGS equipment in 1995 and 1996 maps of the natural radioactivity have been produdced for selected areas in Latvia. The calibration of the quipment have been improved by comparisons with soil sample measurements....

Workflow with pitfalls to derive a regional airborne magnetic compilation

Science.gov (United States)

Brönner, Marco; Baykiev, Eldar; Ebbing, Jörg

2017-04-01

Today, large scale magnetic maps are usually a patchwork of different airborne surveys from different size, different resolution and different years. Airborne magnetic acquisition is a fast and economic method to map and gain geological and tectonic information for large areas, onshore and offshore. Depending on the aim of a survey, acquisition parameters like altitude and profile distance are usually adjusted to match the purpose of investigation. The subsequent data processing commonly follows a standardized workflow comprising core-field subtraction and line leveling to yield a coherent crustal field magnetic grid for a survey area. The resulting data makes it possible to correlate with geological and tectonic features in the subsurface, which is of importance for e.g. oil and mineral exploration. Crustal scale magnetic interpretation and modeling demand regional compilation of magnetic data and the merger of adjacent magnetic surveys. These studies not only focus on shallower sources, reflected by short to intermediate magnetic wavelength anomalies, but also have a particular interest in the long wavelength deriving from deep seated sources. However, whilst the workflow to produce such a merger is supported by quite a few powerful routines, the resulting compilation contains several pitfalls and limitations, which were discussed before, but still are very little recognized. The maximum wavelength that can be resolved of each individual survey is directly related to the survey size and consequently a merger will contribute erroneous long-wavelength components in the magnetic data compilation. To minimize this problem and to homogenous the longer wavelengths, a first order approach is the combination of airborne and satellite magnetic data commonly combined with the compilation from airborne data, which is sufficient only under particular preconditions. A more advanced approach considers the gap in frequencies between airborne and satellite data, which motivated

Airborne laser altimetry survey of Glaciar Tyndall, Patagonia

DEFF Research Database (Denmark)

Keller, K.; Casassa, G.; Rivera, A.

2007-01-01

The first airborne laser altimetry measurements of a glacier in South America are presented. Data were collected in November of 2001 over Glaciar Tyndall, Torres del Paine National Park, Chilean Patagonia, onboard a Twin Otter airplane of the Chilean Air Force. A laser scanner with a rotating...

Data processing of remotely sensed airborne hyperspectral data using the Airborne Processing Library (APL): Geocorrection algorithm descriptions and spatial accuracy assessment

Science.gov (United States)

Warren, Mark A.; Taylor, Benjamin H.; Grant, Michael G.; Shutler, Jamie D.

2014-03-01

Remote sensing airborne hyperspectral data are routinely used for applications including algorithm development for satellite sensors, environmental monitoring and atmospheric studies. Single flight lines of airborne hyperspectral data are often in the region of tens of gigabytes in size. This means that a single aircraft can collect terabytes of remotely sensed hyperspectral data during a single year. Before these data can be used for scientific analyses, they need to be radiometrically calibrated, synchronised with the aircraft's position and attitude and then geocorrected. To enable efficient processing of these large datasets the UK Airborne Research and Survey Facility has recently developed a software suite, the Airborne Processing Library (APL), for processing airborne hyperspectral data acquired from the Specim AISA Eagle and Hawk instruments. The APL toolbox allows users to radiometrically calibrate, geocorrect, reproject and resample airborne data. Each stage of the toolbox outputs data in the common Band Interleaved Lines (BILs) format, which allows its integration with other standard remote sensing software packages. APL was developed to be user-friendly and suitable for use on a workstation PC as well as for the automated processing of the facility; to this end APL can be used under both Windows and Linux environments on a single desktop machine or through a Grid engine. A graphical user interface also exists. In this paper we describe the Airborne Processing Library software, its algorithms and approach. We present example results from using APL with an AISA Eagle sensor and we assess its spatial accuracy using data from multiple flight lines collected during a campaign in 2008 together with in situ surveyed ground control points.

Airborne gamma-ray spectrometer and magnetometer survey, Devils Lake quadrangle, North Dakota. Final report

International Nuclear Information System (INIS)

1981-05-01

During the months of June through October, 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 2 0 x 1 0 NTMS quadrangles located in the states of Minnesota and Wisconsin and seven (7) 2 0 x 1 0 NTMS quadrangles in North and South Dakota. This report discusses the results obtained over the Devil's Lake map area of North Dakota. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps

Airborne gamma-ray spectrometer and magnetometer survey: Peoria, Decater, Belleville Quadrangles, (IL). Final report

International Nuclear Information System (INIS)

1981-01-01

An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Peoria, Decatur, and Belleville, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer with a large crystal volume, and with a high sensitivity proton procession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedures, the data processing procedures, the data presentation, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

Idaho Batholith Study Area Gravity Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (32,152 records) were compiled by the U. S. Geological Survey. This data base was received on February 23, 1993. Principal gravity...

Maine Offshore Free-air Anomaly Gravity

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (5,363 records) were compiled by the U. S. Geological Survey. This data base was received on February 23, 1993. Principal gravity parameters...

The quest for the perfect gravity anomaly: Part 2 - Mass effects and anomaly inversion

Science.gov (United States)

Keller, Gordon R.; Hildenbrand, T.G.; Hinze, W. J.; Li, X.; Ravat, D.; Webring, M.

2006-01-01

Gravity anomalies have become an important tool for geologic studies since the widespread use of high-precision gravimeters after the Second World War. More recently the development of instrumentation for airborne gravity observations, procedures for acquiring data from satellite platforms, the readily available Global Positioning System for precise vertical and horizontal control, improved global data bases, and enhancement of computational hardware and software have accelerated the use of the gravity method. As a result, efforts are being made to improve the gravity databases that are made available to the geoscience community by broadening their observational holdings and increasing the accuracy and precision of the included data. Currently the North American Gravity Database as well as the individual databases of Canada, Mexico, and the United States of America are being revised using new formats and standards. The objective of this paper is to describe the use of the revised standards for gravity data processing and modeling and there impact on geological interpretations. ?? 2005 Society of Exploration Geophysicists.

Planning a radar system for protection from the airborne threat

International Nuclear Information System (INIS)

Greneker, E.F.; McGee, M.C.

1986-01-01

A planning methodology for developing a radar system to protect nuclear materials facilities from the airborne threat is presented. Planning for physical security to counter the airborne threat is becoming even more important because hostile acts by terrorists are increasing and airborne platforms that can be used to bypass physical barriers are readily available. The comprehensive system planning process includes threat and facility surveys, defense hardening, analysis of detection and early warning requirements, optimization of sensor mix and placement, and system implementation considerations

Structural modeling of the Vichada impact structure from interpreted ground gravity and magnetic anomalies

International Nuclear Information System (INIS)

Hernandez, Orlando; Khurama, Sait; Alexander, Gretta C

2011-01-01

A prominent positive free-air gravity anomaly mapped over a roughly 50-km diameter basin is consistent with a mascon centered on (4 degrades 30 minutes N, 69 degrades 15 minutes W) in the Vichada Department, Colombia, South America. Ground follow up gravity and magnetic anomalies were modeled confirming the regional free air gravity anomalies. These potential field anomalies infer a hidden complex impact basin structure filled with tertiary sedimentary rocks and recent quaternary deposits. Negative Bouguer anomalies of 8 mgals to 15 mgals amplitude are associated with a concentric sedimentary basin with a varying thickness from 100 m to 500 m in the outer rings to 700 m to 1000 m at the center of the impact crater basin. Strong positive magnetic anomalies of 100 nt to 300 nt amplitude infer the presence of a local Precambrian crystalline basement that was affected by intensive faulting producing tectonic blocks dipping to the center of the structure, showing a typical domino structure of impact craters such as that of Sudbury, Ontario, Canada. Basic to intermediate mineralized veins and dikes with contrasting density and magnetic susceptibility properties could be emplaced along these faulting zones, as inferred from local gravity and magnetic highs. The geologic mapping of the area is limited by the flat topography and absence of outcrops/ geomorphologic units. Nevertheless, local normal faults along the inner ring together with radially sparse irregular blocks over flat terrains can be associated with terraced rims or collapse of the inner crater structure and eject blanket, respectively. A detailed airborne electromagnetic survey is recommended to confirm the gravity and magnetic anomalies together with a seismic program to evaluate the economic implications for energy and mineral exploration of the Vichada impact structure.

MX Siting Investigation, Gravity Survey - Delamar Valley, Nevada.

Science.gov (United States)

1981-07-20

reduces the data to Simple Bouguer Anomaly (see Section A1.4, Appendix A1.0). The Defense Mapping Agency Aerospace Center (DMAAC), St. Louis, Missouri...DRAWINGS Drawing Number 1 Complete Bouguer Anomaly Contours 2 Depth to Rock -Interpreted from In Pocket at Gravity Data End of Report iv E-TR-33-DM...ErtPX E-TR-3 3-DM 6 2.0 GRAVITY DATA REDUCTION DMAHTC/GSS obtained the basic observations for the new stations and reduced them to Simple Bouguer

Evaluating natural radiation level by existing airborne radioactive data

International Nuclear Information System (INIS)

Mingkao, Hu; Changqing, Han; Jiangqi, Fang; Zhengxin, Shen

2002-01-01

Airborne Survey and Remote Sensing Center of Nuclear Industry, founded in the middle of 1950s, is a unique unit specialized in uranium exploration by airborne radioactive survey in China. Large numbers of airborne data of radioactivity and abundant experience have been accumulated for more than 40 years. All-round detailed investigation of environmental radiation levels in our country will not be completed in the near future. Thus, at present it is considered to evaluate natural radiation levels using the existing radioactive data. This paper introduces the results of analysis and study comparing airborne radioactive data for radiation environmental evaluation obtained from survey area in Gansu, China, in the 2001 with the measurement results by ground gamma ray radiation dose-rate instrument for environment. The air-earth inter-comparison error does not exceed 30% at radiation fields with a definite area, and the air-earth inter-comparison error does not exceed 60% at outcrop of granite. In 6km long profile that has various circumstances, such as desert, Gobi, farmland and residential area, minimum of air absorbed dose rate is 47nGy/h at an altitude of 1 meter above the soil plane, maximum is 68nGy/h. The inter-comparison errors are usually less than 20%, and maximum is 25.38%. This shows that it is feasible to obtain natural radiation levels rapidly if we could use the existing radioactive data adequately and make some correction, such as geology factor

Gravity Data For The State of Utah

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (41,960 records) were compiled by the U. S. Geological Survey. This data base was received on February 23, 1993. Principal gravity...

Gravity Data For The State of Ohio

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (6,591 records) were compiled by the U. S. Geological Survey. This data base was received on February 23, 1993. Principal gravity parameters...

Gravity Data For The Maryland/Virginia Area

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (5,905 records) were compiled by the U. S. Geological Survey. This data base was received on July 11, 1997. Principal gravity parameters...

Airborne gamma ray spectrometry in certain areas of the Islamic Republic of Iran and its results - correlation to the other usages

International Nuclear Information System (INIS)

Soleimani, G.; Yegani, F.S.

1997-01-01

Airborne survey can be utilized as a multipurpose data in different fields such as exploration, health physics, environmental studies and so on. The well known advantages of airborne survey include rapidity, more extent of surveyed area, the possibility of application in unaccessible regions where no other methods can be utilized. More than one third of Iran territory i.e. about 600,000 km 2 has been surveyed by magnetic and spectral gamma ray airborne. This survey is one of the largest and most highly specified survey of its type ever attempted. Extremely large quantities of data were generated during the survey which can be used as a baseline information. (author)

Airborne geophysical survey of the catastrophic landslide at Stože, Log pod Mangrtom, as a test of an innovative approach for landslide mapping in steep alpine terrains

Directory of Open Access Journals (Sweden)

I. Baroň

2013-10-01

Full Text Available Airborne geophysics is a promising method for investigating landslides. Here we present a case study of multisensor airborne geophysical survey at the catastrophic landslide Stože near Log pod Mangrtom in Slovenia, which was conducted in the framework of the European FP7th Project "SafeLand". Based on the survey itself and achieved results, we discuss applicability, limits, and benefits and costs of the method for investigating landslides in steep alpine terrains. Despite of several operational constraints, the airborne electromagnetic survey of the area well presented the lithological pattern and water saturation. The high resistivity regions mostly indicated drained slope scree and landslide mass, drained and loosened material of the moraine deposit in the tension zone of the landslide with present cracks and cavities. The minima of the resistivity pattern were attributed to the outcrop of marls rich in clay, to water-saturated moraine deposit above impermeable marls in the tension zone, and to water-saturated porous alluvial gravel and landslide scree along the Koritnica River. The magnetic survey proved to be inapplicable for such a small and rough area. The Potassium and Thorium maps, on the other hand, both well identified the regions of tension inside the landslide zone, outcrops of marls and dolomite, clay-rich colluvium, weathered zones along a regional tectonic fault, and alluvial deposits and deposits of debris flows, and the minima of the 137Cs clearly revealed the zones of material removal due to recent mass movements.

Qualitative Interpretation Of Aerogravity And Aeromagnetic Survey Data Over The South Western Part Of The Volta River Basin Of Ghana

Directory of Open Access Journals (Sweden)

George Hinson

2015-04-01

Full Text Available Abstract The study area South western part of Volta River Basin of Ghana covering an area of 8570 km2 which is one-eleventh the area of the Volta River basin of Ghana has been subjected to numerous academic research works but geophysical survey works because of virtual perceptive reasons. It is now believed to overly mineral-rich geological structures hence the use of magnetic and gravity survey methods to bring out these mineral-rich geological structures.Geographically it study area is located at the south western part of the Voltaian basin at latitudes 07o 00 N and 08o 00 N and longitudes 02o 00 W and 01o 00 W respectively. Airborne gravity and magnetic survey methods were employed in the data collection. The field data correction and error reduction were applied to the two raw data on the field after which Geosoft Oasis Montaj 7.01 Encom Profile Analysis P.A 11 and 13 Model Vision 12 and ArcGIS 10.0 were used to process enhance e.g. reduce to pole at low latitude first vertical derivative etc. model the reduced and corrected airborne magnetic data and also to produce maps from them data. Low-to-moderate-to-high gravity and magnetic anomalies were obtained in the complete Bouguer anomaly CBA and total magnetic intensity TMI reduced to pole at low latitude with many of these anomalies trending NE-SW by which the Birimian Metasediments and Metavolcanics can be said to be part of the causative structures of these anomalies with cross-cut NW-SE faults. From the quantitative point of view the intrusive granitic bodies of the study area have a mean depth location of 1.7 km while the isolated anomaly is located at a depth of 1.4 km computed from Euler deconvolution. The NE-SW trending anomalies show the trend direction of their causative structures which are the basement rocks and the basinal intrusive bodies.

Airborne laser: a tool to study landscape surface features

International Nuclear Information System (INIS)

Ritchie, J.C.; Jackson, T.J.; Everitt, J.H.; Escobar, D.E.; Murphey, J.B.; Grissinger, E.H.

1992-01-01

Landscape surface features related to erosion and hydrology were measured using an airborne laser profiler. The airborne laser profiler made 4,000 measurements per second with a recording accuracy of 5 cm (1.9 inches) on a single measurement. Digital data from the laser are recorded and analyzed with a personal computer. These airborne laser profiles provide information on surface landscape features. Topography and canopy heights, cover, and distribution of natural vegetation were determined in studies in South Texas. Laser measurements of shrub cover along flightlines were highly correlated (R 2 = 0.98) with ground measurements made with line-intercept methods. Stream channel cross sections on Goodwin Creek in Mississippi were measured quickly and accurately with airborne laser data. Airborne laser profile data were used to measure small gullies in a level fallow field and in field with mature soybeans. While conventional ground-based techniques can be used to make these measurements, airborne laser profiler techniques allow data to be collected quickly, at a high density, and in areas that are essentially inaccessible for ground surveys. Airborne laser profiler data can quantify landscape features related to erosion and runoff, and the laser proler has the potential to be a useful tool for providing other data for studying and managing natural resources

ANWR and Alaska Peninsula Gravity Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (1252 records) were compiled by the U.S. Geological Survey and the State of Alaska Division of Geological & Geophysical Surveys. This...

Airborne gamma-ray spectrometer and magnetometer survey: Lund quadrangle, Ely quadrangle, Nevada. Volume I. Final report

International Nuclear Information System (INIS)

1980-01-01

An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Ely and Lund 1:250,000 National Topographic Map Series (NTMS quadrangle maps). The survey was part of DOE's National Uranium Resource Evaluation (NURE) Aerial Radiometric Reconnaissance program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and interpretation methodology. Volume II contains the data displays for a quadrangle and the interpretation results

Gravity Data for Southwestern Alaska #2

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (1294 records) were compiled by the Alaska Geological Survey and the U.S. Geological Survey, Menlo Park, California. This data base was...

Detailed magnetic and gravity surveys around the hydrothermal area off Kumejima Island in the Mid-Okinawa Trough, southwestern Japan

Science.gov (United States)

Kitada, K.; Kasaya, T.; Iwamoto, H.; Nogi, Y.

2017-12-01

The Okinawa Trough is an active back-arc basin formed by the rifting associated with extension of the continental margin behind the Ryukyu trench. New hydrothermal sites were recently discovered off Kumejima Island in the Mid-Okinawa Trough and the hydrothermal mineral deposits were identified by seafloor surveys and rock samplings by ROV (e.g., JOGMEC, 2015). In order to characterize the sub-seafloor structures and the spatial distribution of the magmatic activity around the sites, we conducted the dense magnetic, gravity and bathymetric surveys with a line spacing of 0.5 nmi aboard the R/Vs Yokosuka and Kairei, operated by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) in 2016. The geophysical data collected during the previous cruises in the area by JAMSTEC were additionally used for this study. Magnetic anomaly was calculated by subtracting the IGRF model and the magnetization intensity was estimated by the method of Parker and Huestis (1974). Free-air gravity anomaly was calculated with subtracting the normal gravity field and with corrections of the drift and of the Eötvös effect. Bouguer gravity anomaly was calculated based on the method of Parker (1972). The magnetization intensity and the Bouguer gravity anomaly reveal three characteristics of the hydrothermal area off Kumejima Island: 1) The distribution of magnetization around the hydrothermal sites shows two different types of sub-seafloor magnetic features. One is corresponded to the submarine knolls with a relatively high magnetization of 4 A/M. The other is an ENE-WSW trending magnetization distribution with relatively high and low intensities, which is consistent with the trend of the bathymetric lineament. These features are considered to be formed by magmatism associated with submarine volcanoes and back-arc rifting. 2) The reduced magnetization zone corresponding to the hydrothermal area probably attributes to hydrothermal alteration of the host rock. 3) The hydrothermal

Testing gravity with EG: mapping theory onto observations

Science.gov (United States)

Leonard, C. Danielle; Ferreira, Pedro G.; Heymans, Catherine

2015-12-01

We present a complete derivation of the observationally motivated definition of the modified gravity statistic EG. Using this expression, we investigate how variations to theory and survey parameters may introduce uncertainty in the general relativistic prediction of EG. We forecast errors on EG for measurements using two combinations of upcoming surveys, and find that theoretical uncertainties may dominate for a futuristic measurement. Finally, we compute predictions of EG under modifications to general relativity in the quasistatic regime, and comment on the pros and cons of using EG to test gravity with future surveys.

Michigan Magnetic and Gravity Maps and Data: A Website for the Distribution of Data

Science.gov (United States)

Daniels, David L.; Kucks, Robert P.; Hill, Patricia L.; Snyder, Stephen L.

2009-01-01

This web site provides the best available, public-domain, aeromagnetic and gravity data in the State of Michigan and merges these data into composite grids that are available for downloading. The magnetic grid is compiled from 25 separate magnetic surveys that have been knit together to form a single composite digital grid and map. The magnetic survey grids have been continued to 305 meters (1,000 feet) above ground and merged together to form the State compilation. A separate map shows the location of the aeromagnetic surveys, color-coded to the survey flight-line spacing. In addition, a complete Bouguer gravity anomaly grid and map were generated from more than 20,000 gravity station measurements from 33 surveys. A table provides the facts about each gravity survey where known.

Significance of radioelement concentration measurements made by airborne gamma-ray spectrometry over the Canadian Shield

International Nuclear Information System (INIS)

Charbonneau, B.W.; Killeen, P.G.; Carson, J.M.; Cameron, G.W.; Richardson, K.A.

1976-01-01

Results of airborne gamma-ray spectrometer surveys conducted by the Geological Survey of Canada are presented as maps contoured in units of radioelement and concentration ratios. These contoured values represent the average surface concentrations of the radioelements over areas of the order of several square kilometres. The relationship between this ''average surface concentration'' and the radioelement concentration in bedrock underlying the area depends on: (1) the percentage of outcrop; (2) the relation between overburden and bedrock radioelement concentration; (3) percentage of marshland or surface water in the area; (4) soil moisture; and (5) density of vegetation. More than 2500 portable gamma-ray spectrometer analyses of outcrop and overburden have been made in the Bancroft, Elliot Lake and Fort Smith areas of the Canadian Precambrian Shield. In the areas examined, the radioelement concentrations in glacial drift reflect the concentrations in the underlying bedrock. Rocks with near-crustal average contents of thorium, uranium and potassium are overlain by glacial drift having approximately the same concentrations. As the concentration in bedrock increases, the concentration in the local overburden also increases, but not to the same extent. In addition, in-situ gamma-ray spectrometry measurements were made at almost 1000 stations within the area of airborne surveys near Mont Laurier and Elliot Lake. These ground measurements were compared with the airborne measurements by averaging the values for all those ground stations located in the areas between each contour level on airborne maps. Radioelement concentrations in bedrock are considerably higher than corresponding airborne measurements, and this difference between bedrock and airborne values increases at higher radioelement concentrations. Radioelement concentrations in glacial drift are only slightly higher than airborne contour values for the same area. Airborne contour maps of the radioelement ratios

An airborne gamma ray snow survey of a forest covered area with a deep snowpack

International Nuclear Information System (INIS)

Glynn, J.E.; Carroll, T.R.; Holman, P.B.; Grasty, R.L.

1988-01-01

Problems arising from the airborne gamma ray measurement of snow water equivalent over a forest covered deep snowpack are examined. The principal sources of error are believed to be due to the radioactivity in the biomass and to variability in the snow cover. A theoretical model is developed to correct the airborne measurements for these sources of error. The application of the theory to data collected over the St. John River Basin, located in the eastern part of Canada and the United States, is found to significantly improve the airborne results

Airborne gamma-ray survey around the Negoro fault. 1; Negoro danso shuhen chiiki ni okeru kuchu {gamma} sen tansa. 1

Energy Technology Data Exchange (ETDEWEB)

Nakayama, E.; Kasuya, Y.; Hasegawa, H. [Aero Asahi Corp., Tokyo (Japan); Tsukuda, E. [Geological Survey of Japan, Tsukuba (Japan)

1997-05-27

An airborne gamma-ray survey was carried out to investigate the active fault system in the central structure line in the peripheral area of the city of Wakayama. At the same time, with an objective to enhance applicability of the airborne gamma-ray survey to active fault investigation, fundamental data were acquired and discussed. The measurement data were processed according to the standard method specified by IAEA. An ID-FFT filter and a nonlinear filter were employed to extract anomalous gamma-ray intensity values. The gamma-ray intensity distribution chart shows a noticeable positive anomalous area extending from the central part of the western edge to the north-east direction. This area agrees nearly well with the Negoro fault, but its peak portion is positioned slightly more to south than the position of the Negoro fault shown in existing data. The Sakuraike fault and the vicinity of the central structure line also show positive anomaly as a whole, particularly remarkably in the vicinity of their converging portion. However, differing from the vicinity of the Negoro fault, the areas are not extracted as an anomalous area which has directionality and extends in a line form. One of the factors for this would be that it is a fault in unsolidified deposits with low opening trend, differing from the one in solidified rocks. 1 fig., 3 tabs.

Model-independent constraints on modified gravity from current data and from the Euclid and SKA future surveys

Energy Technology Data Exchange (ETDEWEB)

Taddei, Laura; Martinelli, Matteo; Amendola, Luca, E-mail: taddei@thphys.uni-heidelberg.de, E-mail: martinelli@lorentz.leidenuniv.nl, E-mail: amendola@thphys.uni-heidelberg.de [Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany)

2016-12-01

The aim of this paper is to constrain modified gravity with redshift space distortion observations and supernovae measurements. Compared with a standard ΛCDM analysis, we include three additional free parameters, namely the initial conditions of the matter perturbations, the overall perturbation normalization, and a scale-dependent modified gravity parameter modifying the Poisson equation, in an attempt to perform a more model-independent analysis. First, we constrain the Poisson parameter Y (also called G {sub eff}) by using currently available f σ{sub 8} data and the recent SN catalog JLA. We find that the inclusion of the additional free parameters makes the constraints significantly weaker than when fixing them to the standard cosmological value. Second, we forecast future constraints on Y by using the predicted growth-rate data for Euclid and SKA missions. Here again we point out the weakening of the constraints when the additional parameters are included. Finally, we adopt as modified gravity Poisson parameter the specific Horndeski form, and use scale-dependent forecasts to build an exclusion plot for the Yukawa potential akin to the ones realized in laboratory experiments, both for the Euclid and the SKA surveys.

Model-independent constraints on modified gravity from current data and from the Euclid and SKA future surveys

International Nuclear Information System (INIS)

Taddei, Laura; Martinelli, Matteo; Amendola, Luca

2016-01-01

The aim of this paper is to constrain modified gravity with redshift space distortion observations and supernovae measurements. Compared with a standard ΛCDM analysis, we include three additional free parameters, namely the initial conditions of the matter perturbations, the overall perturbation normalization, and a scale-dependent modified gravity parameter modifying the Poisson equation, in an attempt to perform a more model-independent analysis. First, we constrain the Poisson parameter Y (also called G eff ) by using currently available f σ 8 data and the recent SN catalog JLA. We find that the inclusion of the additional free parameters makes the constraints significantly weaker than when fixing them to the standard cosmological value. Second, we forecast future constraints on Y by using the predicted growth-rate data for Euclid and SKA missions. Here again we point out the weakening of the constraints when the additional parameters are included. Finally, we adopt as modified gravity Poisson parameter the specific Horndeski form, and use scale-dependent forecasts to build an exclusion plot for the Yukawa potential akin to the ones realized in laboratory experiments, both for the Euclid and the SKA surveys.

Report on gravity measurements and replacement of an unmanned magnetometer in the Sor Rondane Mountains, Eastern Dronning Maud Land, 2013 (JARE-55

Directory of Open Access Journals (Sweden)

Yusuke Suganuma

2014-11-01

Full Text Available Gravity measurements, replacement of the unmanned magnetometer, and a reconnaissance flight to the Belgica Mountains were carried out in the Sor Rondane Mountains as a part of the 55 th Japanese Antarctic Research Expedition (JARE-55. The field party comprised two geodesists, one geomorphologists, and one magnetospheric scientist. The Belgian Antarctic Research Expedition (BELARE and International Polar Foundation (IPF supported this field expedition. Dronning Maud Land Air Network (DROMLAN provided airborne access from Cape Town, South Africa to the Sor Rondane Mountains via Novolazarevskaya Airbase. The survey areas of this field expedition are the central parts of the Sor Rondane Mountains and the Belgica Mountains. This report summarizes the field expedition in terms of operations, logistics, and weather observations.

Occupational exposure to beryllium in French enterprises: a survey of airborne exposure and surface levels.

Science.gov (United States)

Vincent, Raymond; Catani, Jacques; Créau, Yvon; Frocaut, Anne-Marie; Good, Andrée; Goutet, Pierre; Hou, Alain; Leray, Fabrice; André-Lesage, Marie-Ange; Soyez, Alain

2009-06-01

An assessment survey of occupational exposure to beryllium (Be) was conducted in France between late 2004 and the end of 2006. Exposure estimates were based on the analytical results of samples collected from workplace air and from work surfaces in 95 facilities belonging to 37 sectors of activity. The results of this study indicated airborne Be concentrations in excess of the occupational exposure limit value of 2 microg m(-3) recommended in France. Metallurgy and electronic component manufacturing represented the activities and occupations where workers had the highest arithmetic mean exposures to Be. Surface contamination levels were also high and frequently exceeded thresholds recommended by different bodies. These results should prompt the development of prevention programmes that include Be substitution, process control and surface decontamination, in conjunction with suitable medical surveillance.

Alaska1(ak1_wpn) Gravity Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (10,578 records) were compiled by the U.S. Geological Survey and the State of Alaska Division of Geological & Geophysical Surveys. This...

A Monte Carlo approach to constraining uncertainties in modelled downhole gravity gradiometry applications

Science.gov (United States)

Matthews, Samuel J.; O'Neill, Craig; Lackie, Mark A.

2017-06-01

Gravity gradiometry has a long legacy, with airborne/marine applications as well as surface applications receiving renewed recent interest. Recent instrumental advances has led to the emergence of downhole gravity gradiometry applications that have the potential for greater resolving power than borehole gravity alone. This has promise in both the petroleum and geosequestration industries; however, the effect of inherent uncertainties in the ability of downhole gravity gradiometry to resolve a subsurface signal is unknown. Here, we utilise the open source modelling package, Fatiando a Terra, to model both the gravity and gravity gradiometry responses of a subsurface body. We use a Monte Carlo approach to vary the geological structure and reference densities of the model within preset distributions. We then perform 100 000 simulations to constrain the mean response of the buried body as well as uncertainties in these results. We varied our modelled borehole to be either centred on the anomaly, adjacent to the anomaly (in the x-direction), and 2500 m distant to the anomaly (also in the x-direction). We demonstrate that gravity gradiometry is able to resolve a reservoir-scale modelled subsurface density variation up to 2500 m away, and that certain gravity gradient components (Gzz, Gxz, and Gxx) are particularly sensitive to this variation in gravity/gradiometry above the level of uncertainty in the model. The responses provided by downhole gravity gradiometry modelling clearly demonstrate a technique that can be utilised in determining a buried density contrast, which will be of particular use in the emerging industry of CO2 geosequestration. The results also provide a strong benchmark for the development of newly emerging prototype downhole gravity gradiometers.

The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: constraining modified gravity

Science.gov (United States)

Mueller, Eva-Maria; Percival, Will; Linder, Eric; Alam, Shadab; Zhao, Gong-Bo; Sánchez, Ariel G.; Beutler, Florian; Brinkmann, Jon

2018-04-01

We use baryon acoustic oscillation and redshift space distortion from the completed Baryon Oscillation Spectroscopic Survey, corresponding to Data Release 12 of the Sloan Digital Sky Survey, combined sample analysis in combination with cosmic microwave background, supernova, and redshift space distortion measurements from additional spectroscopic surveys to test deviations from general relativity. We present constraints on several phenomenological models of modified gravity: First, we parametrize the growth of structure using the growth index γ, finding γ = 0.566 ± 0.058 (68 per cent C.L.). Secondly, we modify the relation of the two Newtonian potentials by introducing two additional parameters, GM and GL. In this approach, GM refers to modifications of the growth of structure whereas GL to modification of the lensing potential. We consider a power law to model the redshift dependence of GM and GL as well as binning in redshift space, introducing four additional degrees of freedom, GM(z 0.5), GL(z 0.5). At 68 per cent C.L., we measure GM = 0.980 ± 0.096 and GL = 1.082 ± 0.060 for a linear model, GM = 1.01 ± 0.36 and GL = 1.31 ± 0.19 for a cubic model as well as GM(z 0.5) = 0.986 ± 0.022, GL(z 0.5) = 1.037 ± 0.029. Thirdly, we investigate general scalar tensor theories of gravity, finding the model to be mostly unconstrained by current data. Assuming a one-parameter f(R) model, we can constrain B0 < 7.7 × 10-5 (95 per cent C.L). For all models we considered, we find good agreement with general relativity.

The International Gravity Field Service (IGFS): Present Day Activities And Future Plans

Science.gov (United States)

Barzaghi, R.; Vergos, G. S.

2016-12-01

IGFS is a unified "umbrella" IAG service that coordinates the servicing of the geodetic and geophysical community with gravity field related data, software and information. The combined data of the IGFS entities will include global geopotential models, terrestrial, airborne, satellite and marine gravity observations, Earth tide data, GPS/levelling data, digital models of terrain and bathymetry, as well as ocean gravity field and geoid from satellite altimetry. The IGFS structure is based on the Gravity Services, the "operating arms" of IGFS. These Services related to IGFS are: BGI (Bureau Gravimetrique International), Toulouse, France ISG (International Service for the Geoid), Politecnico di Milano, Milano, Italy IGETS (International Geodynamics and Earth Tides Service), EOST, Strasbourg, France ICGEM (International Center for Global Earth Models), GFZ, Potsdam, Germany IDEMS (International Digital Elevation Model Service), ESRI, Redlands, CA, USA The Central Bureau, hosted at the Aristotle Thessaloniki University, is in charge for all the interactions among the services and the other IAG bodies, particularly GGOS. In this respect, connections with the GGOS Bureaus of Products and Standards and of Networks and Observations have been recently strengthened in order to align the Gravity services to the GGOS standards. IGFS is also strongly involved in the most relevant projects related to the gravity field such as the establishment of the new Global Absolute Gravity Reference System and of the International Height Reference System. These projects, along with the organization of Geoid Schools devoted to methods for gravity and geoid estimate, will play a central role in the IGFS future actions in the framework of GGOS.

Geological interpretation of an airborne gamma-ray spectrometer survey of the Hearne Lake area, Northwest Territories

International Nuclear Information System (INIS)

Newton, A.R.; Slaney, V.R.

1978-01-01

This study shows how large volumes of airborne data can be displayed in a simple format which provides both mapping and exploration geologists with information not easily obtained from the original data. Eleven lines or part-lines from a gamma-ray survey of the Hearne Lake area were chosen as test lines, and airphotos were used to identify outcrops of each rock type and the distribution of overburden, swamp and water along each line. Geological maps were used to locate the test lines and to provide a listing of the rock types in the area. With this information, it was possible to calculate the average radioelement characteristics of each rock type and to group the rock signatures into a number of rock classes. The techniques described are most usefully applied to those areas where the outcrop is extensive, where some form of geological map already exists, where there are airphotos at scales of 1:30,000 or larger, and where the gamma-ray survey lines are less than 2.5 km apart

Gravity survey of groundwater characterization at Labuan Basin

Science.gov (United States)

Handayani, L.; Wardhana, D. D.; Hartanto, P.; Delinom, R.; Sudaryanto; Bakti, H.; Lubis, RF

2018-02-01

Labuan groundwater basin currently has an abundance of water. As a deltaic area of Lada Bay, groundwater supply comes from local precipitation and also from recharge region in mountain ranges surrounding. However, Labuan has been experiencing a fast economic development with high population and tourism industry growth. Such progress would lead to the increase of water consumption. A comprehensive groundwater management should be prepared for possible future problems. Therefore, a groundwater investigation is a necessary step towards that purpose. Gravity method was applied to identify the regional condition of the basement. The assessment of deep buried basin and basement relationship using gravity data is a challenge in groundwater investigation, but previous studies had indicated the efficiency of the method to obtain basic information and can be used as a foundation for more advanced studies.

Collection of Observed Gravity Values, Absolute Gravity Measurements, Grids and Other Derived Summary Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The National Geophysical Data Center (NGDC) of NOAA, in cooperation with the National Geodetic Survey of NOAA, have published a Gravity CD-ROM containing observed...

Measuring and Modeling the Earth's Gravity - Introduction to Ground-Based Gravity Surveys and Analysis of Local Gravity Data

Energy Technology Data Exchange (ETDEWEB)

Rowe, Charlotte Anne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-11-21

We can measure changes in gravity from place to place on the earth. These measurements require careful recording of location, elevation and time for each reading. These readings must be adjusted for known effects (such as elevation, latitude, tides) that can bias our data and mask the signal of interest. After making corrections to our data, we can remove regional trends to obtain local Bouguer anomalies. The Bouguer anomalies arise from variations in the subsurface density structure. We can build models to explain our observations, but these models must be consistent with what is known about the local geology. Combining gravity models with other information – geologic, seismic, electromagnetic, will improve confidence in the results.

Airborne gamma-ray spectrometry

DEFF Research Database (Denmark)

Hovgaard, Jens

A new method - Noise Adjusted Singular Value Decomposition, NASVD - for processing gamma-ray spectra has been developed as part of a Ph.D. project. By using this technique one is able to decompose a large set of data - for example from airborne gamma-ray surveys - into a few spectral components....... By knowing the spectral components and their amplitudes in each of the measured spectra one is able to extract more information from the data than possible with the methods used otherwise....

Cosmological tests of modified gravity.

Science.gov (United States)

Koyama, Kazuya

2016-04-01

We review recent progress in the construction of modified gravity models as alternatives to dark energy as well as the development of cosmological tests of gravity. Einstein's theory of general relativity (GR) has been tested accurately within the local universe i.e. the Solar System, but this leaves the possibility open that it is not a good description of gravity at the largest scales in the Universe. This being said, the standard model of cosmology assumes GR on all scales. In 1998, astronomers made the surprising discovery that the expansion of the Universe is accelerating, not slowing down. This late-time acceleration of the Universe has become the most challenging problem in theoretical physics. Within the framework of GR, the acceleration would originate from an unknown dark energy. Alternatively, it could be that there is no dark energy and GR itself is in error on cosmological scales. In this review, we first give an overview of recent developments in modified gravity theories including f(R) gravity, braneworld gravity, Horndeski theory and massive/bigravity theory. We then focus on common properties these models share, such as screening mechanisms they use to evade the stringent Solar System tests. Once armed with a theoretical knowledge of modified gravity models, we move on to discuss how we can test modifications of gravity on cosmological scales. We present tests of gravity using linear cosmological perturbations and review the latest constraints on deviations from the standard [Formula: see text]CDM model. Since screening mechanisms leave distinct signatures in the non-linear structure formation, we also review novel astrophysical tests of gravity using clusters, dwarf galaxies and stars. The last decade has seen a number of new constraints placed on gravity from astrophysical to cosmological scales. Thanks to on-going and future surveys, cosmological tests of gravity will enjoy another, possibly even more, exciting ten years.

Implications of Preliminary Gravity and Magnetic Surveys to the Understanding of the Bartlett Springs Fault Zone, Northern California Coast Ranges

Science.gov (United States)

Langenheim, V. E.; Jachens, R. C.; Morin, R. L.; McCabe, C. M.; Page, W. D.

2007-12-01

We use new gravity and magnetic data in the Lake Pillsbury region to help understand the geometry and character of the Bartlett Springs fault zone, one of the three main strands of the San Andreas system north of the San Francisco Bay area. We collected 153 new gravity stations in the Lake Pillsbury region that complement the sparse regional dataset and are used to estimate the thickness of Quaternary deposits in the inferred Gravelly Valley (Lake Pillsbury) pull-apart basin. We also collected 38 line-km of ground magnetic data on roads and 65 line-km by boat on the lake to supplement regional aeromagnetic surveys and to map concealed fault strands beneath the lake. The new gravity data show a significant northwest-striking gravity gradient at the base of which lies the Bartlett Springs fault zone. Superposed on this major east-facing gravity gradient is a 5 mGal low centered on Lake Pillsbury and Gravelly Valley. Inversion of the gravity field for basin thickness assuming a density contrast of 400 kg/m3 indicates the deepest part of the basin is about 400 m and located in the northern part of the valley, although the inversion lacks gravity stations within the lake. The basin is about 3 km wide and 5 km long and basin edges coincide with strands of the Bartlett Springs fault zone. Our gravity data suggest that Potter Valley, which lies between the Maacama and Bartlett Springs faults, is also as much as 400 m deep in the southern part of the valley, although additional data west of the valley would better isolate the gravity low. Geomorphologic characteristics of the valley suggest that this structure has been quiescent during the late Quaternary. Ground magnetic data are very noisy but the data in conjunction with 9.6 km-spaced NURE aeromagnetic lines suggest that regional analog aeromagnetic data flown in 1962 may suffer from location errors. The regional and NURE data show a northwest-striking magnetic high that extends across Lake Pillsbury. The northeast edge

The theoretical study of full spectrum analysis method for airborne gamma-ray spectrometric data

International Nuclear Information System (INIS)

Ni Weichong

2011-01-01

Spectra of airborne gamma-ray spectrometry was found to be the synthesis of spectral components of radioelement sources by analyzing the constitution of radioactive sources for airborne gamma-ray spectrometric survey and establishing the models of gamma-ray measurement. The mathematical equation for analysising airborne gamma-ray full spectrometric data can be expressed into matrix and related expansions were developed for the mineral resources exploration, environmental radiation measurement, nuclear emergency monitoring, and so on. Theoretical study showed that the atmospheric radon could be directly computed by airborne gamma-ray spectrometric data with full spectrum analysis without the use of the accessional upward-looking detectors. (authors)

Preliminary report on geophysics ground follow-up of the 1977 airborne survey in the Wadi Bidah District, Kingdom of Saudi Arabia

Science.gov (United States)

Flanigan, V.J.; Wynn, J.C.; Worl, R.G.; Smith, C.W.

1981-01-01

Reconnaissance geologic and geochemical sampling was made during the 1978 field season at most of the 50 or so electromagnetic anomalies detected in the 1977 airborne electromagnetic (AEM) survey of the Wadi Bidah district. These Phase 1 studies also included reconnaissance geophysical traverses of nine of the AEM conductors. In addition the AEM anomalies were classified on the basis of this reconnaissance work into a list of priority targets for use in economic studies, and six AEM anomalies were selected for further studies.

High-precision gravity measurements using absolute and relative gravimeters at Mount Etna (Sicily, Italy

Directory of Open Access Journals (Sweden)

Ciro Del Negro

2011-12-01

Full Text Available Accurate detection of time gravity changes attributable to the dynamics of volcanoes requires high-precision gravity measurements. With the aim of improving the quality of data from the Mount Etna gravity network, we used both absolute and relative gravimeters in a hybrid method. In this report, some of the techniques for gravity surveys are reviewed, and the results related to each method are compared. We show how the total uncertainty estimated for the gravity measurements performed with this combined use of absolute and relative gravimeters is roughly comparable to that calculated when the measurements are acquired using only relative gravimeters (the traditional method. However, the data highlight how the hybrid approach improves the measurement capabilities for surveying the Mount Etna volcanic area. This approach enhances the accuracy of the data, and then of the four-dimensional surveying, which minimizes ambiguities inherent in the gravity measurements. As a case study, we refer to two gravity datasets acquired in 2005 and 2010 from the western part of the Etna volcano, which included five absolute and 13 relative stations of the Etna gravity network.

Application of Cauchy-type integrals in developing effective methods for depth-to-basement inversion of gravity and gravity gradiometry data

DEFF Research Database (Denmark)

Cai, Hongzhu; Zhdanov, Michael

2015-01-01

to be discretized for the calculation of gravity field. This was especially significant in the modeling and inversion of gravity data for determining the depth to the basement. Another important result was developing a novel method of inversion of gravity data to recover the depth to basement, based on the 3D...... Cauchy-type integral representation. Our numerical studies determined that the new method is much faster than conventional volume discretization method to compute the gravity response. Our synthetic model studies also showed that the developed inversion algorithm based on Cauchy-type integral is capable......One of the most important applications of gravity surveys in regional geophysical studies is determining the depth to basement. Conventional methods of solving this problem are based on the spectrum and/or Euler deconvolution analysis of the gravity field and on parameterization of the earth...

Disentangling dark energy and cosmic tests of gravity from weak lensing systematics

Science.gov (United States)

Laszlo, Istvan; Bean, Rachel; Kirk, Donnacha; Bridle, Sarah

2012-06-01

We consider the impact of key astrophysical and measurement systematics on constraints on dark energy and modifications to gravity on cosmic scales. We focus on upcoming photometric ‘stage III’ and ‘stage IV’ large-scale structure surveys such as the Dark Energy Survey (DES), the Subaru Measurement of Images and Redshifts survey, the Euclid survey, the Large Synoptic Survey Telescope (LSST) and Wide Field Infra-Red Space Telescope (WFIRST). We illustrate the different redshift dependencies of gravity modifications compared to intrinsic alignments, the main astrophysical systematic. The way in which systematic uncertainties, such as galaxy bias and intrinsic alignments, are modelled can change dark energy equation-of-state parameter and modified gravity figures of merit by a factor of 4. The inclusion of cross-correlations of cosmic shear and galaxy position measurements helps reduce the loss of constraining power from the lensing shear surveys. When forecasts for Planck cosmic microwave background and stage IV surveys are combined, constraints on the dark energy equation-of-state parameter and modified gravity model are recovered, relative to those from shear data with no systematic uncertainties, provided fewer than 36 free parameters in total are used to describe the galaxy bias and intrinsic alignment models as a function of scale and redshift. While some uncertainty in the intrinsic alignment (IA) model can be tolerated, it is going to be important to be able to parametrize IAs well in order to realize the full potential of upcoming surveys. To facilitate future investigations, we also provide a fitting function for the matter power spectrum arising from the phenomenological modified gravity model we consider.

Assessment of NASA airborne laser altimetry data using ground-based GPS data near Summit Station, Greenland

Science.gov (United States)

Brunt, Kelly M.; Hawley, Robert L.; Lutz, Eric R.; Studinger, Michael; Sonntag, John G.; Hofton, Michelle A.; Andrews, Lauren C.; Neumann, Thomas A.

2017-03-01

A series of NASA airborne lidars have been used in support of satellite laser altimetry missions. These airborne laser altimeters have been deployed for satellite instrument development, for spaceborne data validation, and to bridge the data gap between satellite missions. We used data from ground-based Global Positioning System (GPS) surveys of an 11 km long track near Summit Station, Greenland, to assess the surface-elevation bias and measurement precision of three airborne laser altimeters including the Airborne Topographic Mapper (ATM), the Land, Vegetation, and Ice Sensor (LVIS), and the Multiple Altimeter Beam Experimental Lidar (MABEL). Ground-based GPS data from the monthly ground-based traverses, which commenced in 2006, allowed for the assessment of nine airborne lidar surveys associated with ATM and LVIS between 2007 and 2016. Surface-elevation biases for these altimeters - over the flat, ice-sheet interior - are less than 0.12 m, while assessments of measurement precision are 0.09 m or better. Ground-based GPS positions determined both with and without differential post-processing techniques provided internally consistent solutions. Results from the analyses of ground-based and airborne data provide validation strategy guidance for the Ice, Cloud, and land Elevation Satellite 2 (ICESat-2) elevation and elevation-change data products.

Airborne Laser Polarization Sensor

Science.gov (United States)

Kalshoven, James, Jr.; Dabney, Philip

1991-01-01

Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

Gravity Data for Southwestern Alaska (1294 records compiled)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (1294 records) were compiled by the Alaska Geological Survey and the U.S. Geological Survey, Menlo Park, California. This data base was...

Alaska Gravity Data per 2 x 4 min Cell (96)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This 2' x 4' gravity density grid for Alaska displays the distribution of about 1.1 million terrestrial and marine gravity data held in the National Geodetic Survey...

Borehole gravity meter survey in drill hole USW G-4, Yucca Mountain Area, Nye County, Nevada

International Nuclear Information System (INIS)

Healey, D.L.; Clutsom, F.G.; Glover, D.A.

1986-01-01

Drill hole USW G-4 was logged with the US Geological Survey borehole gravity meter (BHGM) BH-6 as part of a detailed study of the lithostratigraphic units penetrated by this hole. Because the BHGM measures a larger volume of rock than the conventional gamma-gamma density tool, it provides an independent and more accurate measurement of the in situ average bulk density of thick lithologic units. USW G-4 is an especially important hole because of its proximity to the proposed exploratory shaft at Yucca Mountain. The BHGM data were reduced to interval densities using a free-air gradient (F) of 0.3083 mGal./m (0.09397 mGal/ft) measured at the drill site. The interval densities were further improved by employing an instrument correction factor of 1.00226. This factor was determined from measurements obtained by taking gravity meter BH-6 over the Charleston Peak calibration loop. The interval density data reported herein, should be helpful for planning the construction of the proposed shaft

GRACILE: a comprehensive climatology of atmospheric gravity wave parameters based on satellite limb soundings

Directory of Open Access Journals (Sweden)

M. Ern

2018-04-01

Full Text Available Gravity waves are one of the main drivers of atmospheric dynamics. The spatial resolution of most global atmospheric models, however, is too coarse to properly resolve the small scales of gravity waves, which range from tens to a few thousand kilometers horizontally, and from below 1 km to tens of kilometers vertically. Gravity wave source processes involve even smaller scales. Therefore, general circulation models (GCMs and chemistry climate models (CCMs usually parametrize the effect of gravity waves on the global circulation. These parametrizations are very simplified. For this reason, comparisons with global observations of gravity waves are needed for an improvement of parametrizations and an alleviation of model biases. We present a gravity wave climatology based on atmospheric infrared limb emissions observed by satellite (GRACILE. GRACILE is a global data set of gravity wave distributions observed in the stratosphere and the mesosphere by the infrared limb sounding satellite instruments High Resolution Dynamics Limb Sounder (HIRDLS and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER. Typical distributions (zonal averages and global maps of gravity wave vertical wavelengths and along-track horizontal wavenumbers are provided, as well as gravity wave temperature variances, potential energies and absolute momentum fluxes. This global data set captures the typical seasonal variations of these parameters, as well as their spatial variations. The GRACILE data set is suitable for scientific studies, and it can serve for comparison with other instruments (ground-based, airborne, or other satellite instruments and for comparison with gravity wave distributions, both resolved and parametrized, in GCMs and CCMs. The GRACILE data set is available as supplementary data at https://doi.org/10.1594/PANGAEA.879658.

Tumbleweeds and airborne gravitational noise sources for LIGO

International Nuclear Information System (INIS)

Creighton, Teviet

2008-01-01

The relative positions of the test masses in gravitational-wave detectors will be influenced not only by astrophysical gravitational waves, but also by the fluctuating Newtonian gravitational forces of moving masses in the ground and air around the detector. These effects are often referred to as gravity gradient noise. This paper considers the effects of gravity gradients from density perturbations in the atmosphere, and from massive airborne objects near the detector. These have been discussed previously by Saulson (1984 Phys. Rev. D 30 732), who considered the effects of background acoustic pressure waves and of massive objects moving smoothly past the interferometer; the gravity gradients he predicted would be too small to be of serious concern even for advanced interferometric gravitational-wave detectors. In this paper, I revisit these phenomena, considering transient atmospheric shocks, and estimating the effects of sound waves or objects colliding with the ground or buildings around the test masses. I also consider another source of atmospheric density fluctuations: temperature perturbations that are advected past the detector by the wind. I find that background acoustic noise and temperature fluctuations still produce gravity gradient noise that is below the noise floor even of advanced interferometric detectors, although temperature perturbations carried along non-laminar streamlines could produce noise that is within an order of magnitude of the projected noise floor at 10 Hz. A definitive study of this effect may require better models of the wind flow past a given instrument. I also find that transient shockwaves in the atmosphere could potentially produce large spurious signals, with signal-to-noise ratios in the hundreds in an advanced interferometric detector. These signals could be vetoed by means of acoustic sensors outside of the buildings. Massive wind-borne objects such as tumbleweeds could also produce gravity gradient signals with signal

On background radiation gradients – the use of airborne surveys when searching for orphan sources using mobile gamma-ray spectrometry

International Nuclear Information System (INIS)

Kock, Peder; Rääf, Christopher; Samuelsson, Christer

2014-01-01

Systematic background radiation variations can lead to both false positives and failures to detect an orphan source when searching using car-borne mobile gamma-ray spectrometry. The stochastic variation at each point is well described by Poisson statistics, but when moving in a background radiation gradient the mean count rate will continually change, leading to inaccurate background estimations. Airborne gamma spectrometry (AGS) surveys conducted on the national level, usually in connection to mineral exploration, exist in many countries. These data hold information about the background radiation gradients which could be used at the ground level. This article describes a method that aims to incorporate the systematic as well as stochastic variations of the background radiation. We introduce a weighted moving average where the weights are calculated from existing AGS data, supplied by the Geological Survey of Sweden. To test the method we chose an area with strong background gradients, especially in the thorium component. Within the area we identified two roads which pass through the high-variability locations. The proposed method is compared with an unweighted moving average. The results show that the weighting reduces the excess false positives in the positive background gradients without introducing an excess of failures to detect a source during passage in negative gradients. -- Highlights: • We present a simple method to account for gradients in the natural background radiation. • Gradients in the natural radiation background can be modelled at the ground level using AGS data. • The number of false positives due to background gradients can be reduced by using airborne data

Heliborne time-domain electromagnetic (TEM) surveys for uranium exploration

International Nuclear Information System (INIS)

Chaturvedi, A.K.

2015-01-01

Airborne geophysical surveys have been used extensively in petroleum, mineral exploration, and environmental mapping. Of all the geophysical methods, Electromagnetic (EM) methods, both ground and airborne are used to map the conductive ore bodies buried in the resistive bed rock. Mapping resistivity variations can help unravel complex geological problems and identify areas of hidden potential. Besides the traditional applications to ground water investigations and other natural resource exploration and geological mapping, a number of new applications have been reported. These include hazardous-waste characterization studies, precision agriculture applications, archaeological surveys etc. Airborne Electromagnetic (AEM) methods have undergone rapid improvements over the past few decades. Several new airborne Time Do-main EM (TDEM) systems appeared; existing systems were updated and/or enhanced. The use of natural field (passive) EM surveys continued to increase, with new or improved systems becoming available for both airborne and ground surveys. The number of large airborne survey systems with combined EM, magnetic, gravimetric and gamma-ray spectrometric capabilities also increased. Exploration of a mineral deposit is a multi-stage and multi-disciplinary approach that commences from regional investigations and concludes with establishing of a deposit. As economics play a major role in exploration, a proper integrated study is always beneficial in narrowing down the potential mineral target zones. Heliborne geophysical surveys are being conducted world-wide for exploration of base metals, gold, phosphorite, oil, uranium etc. that are very effective tool in identifying zones of interest accurately, economically and with less span of time. These surveys give a very good insight of surface and sub-surface geophysical signatures that can be attributed to geology with proper modeling. Heliborne Time - domain Electromagnetic (TEM) methods are well known for search of

Quantum gravity and the renormalisation group

International Nuclear Information System (INIS)

Litim, D.

2011-01-01

The Standard Model of particle physics is remarkably successful in describing three out of the four known fundamental forces of Nature. But what is up with gravity? Attempts to understand quantum gravity on the same footing as the other forces still face problems. Some time ago, it has been pointed out that gravity may very well exist as a fundamental quantum field theory provided its high-energy behaviour is governed by a fixed point under the renormalisation group. In recent years, this 'asymptotic safety' scenario has found significant support thanks to numerous renormalisation group studies, lattice simulations, and new ideas within perturbation theory. The lectures will give an introduction into the renormalisation group approach for quantum gravity, aimed at those who haven't met the topic before. After an introduction and overview, the key ideas and concepts of asymptotic safety for gravity are fleshed out. Results for gravitational high-energy fixed points and scaling exponents are discussed as well as key features of the gravitational phase diagram. The survey concludes with some phenomenological implications of fixed point gravity including the physics of black holes and particle physics beyond the Standard Model. (author)

Airborne wireless communication systems, airborne communication methods, and communication methods

Science.gov (United States)

Deaton, Juan D [Menan, ID; Schmitt, Michael J [Idaho Falls, ID; Jones, Warren F [Idaho Falls, ID

2011-12-13

An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

The role of airborne radiometric survey in defining the distribution of phosphate rocks in the Syrian desert and the Northern Palmyrides

International Nuclear Information System (INIS)

Jubeli, Y.M.

2000-01-01

Gamma-ray spectrometry, an effective tool in geological mapping, was used to define boundaries between various lithological formations in three adjacent areas of Central Syria, namely, the Syrian Desert, Ar Rassafeh Badiayat and the Northern Palmyrides mountains. This paper describes the role of an airborne gamma spectrometric survey which was originally undertaken to assist uranium exploration. Interpretation of the total count data obtained through the survey has led to significant modifications and corrections to the previously published distribution map of the Palaeogene phosphate rocks. Another important result to the survey is the discovery of four previously unknown phosphorite horizons in the Rasm Al-Aawabed area of the Northern Palmyrides. In addition, previously unknown phosphatic horizons are outlined in the other study areas. The importance of this technique as an effective prospecting method, not only for U but also for exploring for the economically important phosphorite formations in Syria, is emphasized. Furthermore, its role in geological mapping is stressed, especially in areas that lack sufficient geological data. (author)

Recent advancements in conformal gravity

International Nuclear Information System (INIS)

O’Brien, James G.; Chaykov, Spasen S.; Moss, Robert J.; Dentico, Jeremy; Stulge, Modestas; Stefanski, Brian

2017-01-01

In recent years, due to the lack of direct observed evidence of cold dark matter, coupled with the shrinking parameter space to search for new dark matter particles, there has been increased interest in Alternative Gravitational theories. This paper, addresses three recent advances in conformal gravity, a fourth order renormalizable metric theory of gravitation originally formulated by Weyl, and later advanced by Mannheim and Kazanas. The first section of the paper applies conformal gravity to the rotation curves of the LITTLE THINGS survey, extending the total number of rotation curves successfully fit by conformal gravity to well over 200 individual data sets without the need for additional dark matter. Further, in this rotation curve study, we show how MOND and conformal gravity compare for each galaxy in the sample. Second, we look at the original Zwicky problem of applying the virial theorem to the Coma cluster in order to get an estimate for the cluster mass. However, instead of using the standard Newtonian potential, here we use the weak field approximation of conformal gravity. We show that in the conformal case we can get a much smaller mass estimate and thus there is no apparent need to include dark matter. We then show that this calculation is in agreement with the observational data from other well studied clusters. Last, we explore the calculation of the deflection of starlight through conformal gravity, as a first step towards applying conformal gravity to gravitaitonal lensing. (paper)

Beyond Einstein Gravity A Survey of Gravitational Theories for Cosmology and Astrophysics

CERN Document Server

Faraoni, Valerio

2011-01-01

Beyond Einstein’s Gravity is a graduate level introduction to extended theories of gravity and cosmology, including variational principles, the weak-field limit, gravitational waves, mathematical tools, exact solutions, as well as cosmological and astrophysical applications. The book provides a critical overview of the research in this area and unifies the existing literature using a consistent notation. Although the results apply in principle to all alternative gravities, a special emphasis is on scalar-tensor and f(R) theories. They were studied by theoretical physicists from early on, and in the 1980s they appeared in attempts to renormalize General Relativity and in models of the early universe. Recently, these theories have seen a new lease of life, in both their metric and metric-affine versions, as models of the present acceleration of the universe without introducing the mysterious and exotic dark energy. The dark matter problem can also be addressed in extended gravity. These applications are contr...

Airborne geophysics in Australia: the government contribution

International Nuclear Information System (INIS)

Denham, D.

1997-01-01

Airborne geophysical data sets provide important cost-effective information for resource exploration and land management. Improved techniques, developed recently, now enable high-resolution aeromagnetic and gamma-ray surveys to be used extensively by the resource industries to improve the cost effectiveness of exploration and by governments to encourage resource development and sustainable management of natural resources. Although airborne geophysical techniques have been used extensively and are now used almost routinely by mineral explorers, it is only in the last few years that governments have been involved as major players in the acquisition of data. The exploration industry pioneered the imaging of high-resolution airborne geophysical data sets in the early 1980s and, at the same time, the Northern Territory Government started a modest program of flying the Northern Territory, at 500 m flight-line spacing, to attract mineral exploration. After the start of the National Geoscience Mapping Accord in 1990, the then BMR and its State/Territory counterparts used the new high-resolution data as an essential ingredient to underpin mapping programs. These new data sets proved so valuable that, starting in 1992/93, the annual expenditure by the Commonwealth and States/Northern Territory increased from roughly $2 million per year to a massive $10 million per year. These investments by governments, although unlikely to be permanently sustainable, have been made to encourage and expand exploration activity by providing new high-quality data sets in industry at very low cost. There are now approximately 11 million line-km of airborne geophysical data available in databases held by the Commonwealth, States and Northern Territory. The results so far have seen a significant increase in exploration activity in States that have embarked on this course (e.g. South Australia and Victoria), and the information provided from these surveys is proving crucial to understanding the

Airborne pollen and spore survey in relation to allergy and plant ...

African Journals Online (AJOL)

Airborne bio-particles of allergic significance were recorded at a height of 15m in Nsukka during September 1999 – February 2000. Spores of fungi and pollen grains, which are important part of the exposure that may lead to allergic discomfort and plant diseases, dominated the particles. Other primary sources of the allergic ...

MERGING AIRBORNE LIDAR DATA AND SATELLITE SAR DATA FOR BUILDING CLASSIFICATION

Directory of Open Access Journals (Sweden)

T. Yamamoto

2015-05-01

Full Text Available A frequent map revision is required in GIS applications, such as disaster prevention and urban planning. In general, airborne photogrammetry and LIDAR measurements are applied to geometrical data acquisition for automated map generation and revision. However, attribute data acquisition and classification depend on manual editing works including ground surveys. In general, airborne photogrammetry and LiDAR measurements are applied to geometrical data acquisition for automated map generation and revision. However, these approaches classify geometrical attributes. Moreover, ground survey and manual editing works are finally required in attribute data classification. On the other hand, although geometrical data extraction is difficult, SAR data have a possibility to automate the attribute data acquisition and classification. The SAR data represent microwave reflections on various surfaces of ground and buildings. There are many researches related to monitoring activities of disaster, vegetation, and urban. Moreover, we have an opportunity to acquire higher resolution data in urban areas with new sensors, such as ALOS2 PALSAR2. Therefore, in this study, we focus on an integration of airborne LIDAR data and satellite SAR data for building extraction and classification.

Massive gravity from bimetric gravity

International Nuclear Information System (INIS)

Baccetti, Valentina; Martín-Moruno, Prado; Visser, Matt

2013-01-01

We discuss the subtle relationship between massive gravity and bimetric gravity, focusing particularly on the manner in which massive gravity may be viewed as a suitable limit of bimetric gravity. The limiting procedure is more delicate than currently appreciated. Specifically, this limiting procedure should not unnecessarily constrain the background metric, which must be externally specified by the theory of massive gravity itself. The fact that in bimetric theories one always has two sets of metric equations of motion continues to have an effect even in the massive gravity limit, leading to additional constraints besides the one set of equations of motion naively expected. Thus, since solutions of bimetric gravity in the limit of vanishing kinetic term are also solutions of massive gravity, but the contrary statement is not necessarily true, there is no complete continuity in the parameter space of the theory. In particular, we study the massive cosmological solutions which are continuous in the parameter space, showing that many interesting cosmologies belong to this class. (paper)

Adaptive topographic mass correction for satellite gravity and gravity gradient data

Science.gov (United States)

Holzrichter, Nils; Szwillus, Wolfgang; Götze, Hans-Jürgen

2014-05-01

Subsurface modelling with gravity data includes a reliable topographic mass correction. Since decades, this mandatory step is a standard procedure. However, originally methods were developed for local terrestrial surveys. Therefore, these methods often include defaults like a limited correction area of 167 km around an observation point, resampling topography depending on the distance to the station or disregard the curvature of the earth. New satellite gravity data (e.g. GOCE) can be used for large scale lithospheric modelling with gravity data. The investigation areas can include thousands of kilometres. In addition, measurements are located in the flight height of the satellite (e.g. ~250 km for GOCE). The standard definition of the correction area and the specific grid spacing around an observation point was not developed for stations located in these heights and areas of these dimensions. This asks for a revaluation of the defaults used for topographic correction. We developed an algorithm which resamples the topography based on an adaptive approach. Instead of resampling topography depending on the distance to the station, the grids will be resampled depending on its influence at the station. Therefore, the only value the user has to define is the desired accuracy of the topographic correction. It is not necessary to define the grid spacing and a limited correction area. Furthermore, the algorithm calculates the topographic mass response with a spherical shaped polyhedral body. We show examples for local and global gravity datasets and compare the results of the topographic mass correction to existing approaches. We provide suggestions how satellite gravity and gradient data should be corrected.

GRACILE: a comprehensive climatology of atmospheric gravity wave parameters based on satellite limb soundings

Science.gov (United States)

Ern, Manfred; Trinh, Quang Thai; Preusse, Peter; Gille, John C.; Mlynczak, Martin G.; Russell, James M., III; Riese, Martin

2018-04-01

Gravity waves are one of the main drivers of atmospheric dynamics. The spatial resolution of most global atmospheric models, however, is too coarse to properly resolve the small scales of gravity waves, which range from tens to a few thousand kilometers horizontally, and from below 1 km to tens of kilometers vertically. Gravity wave source processes involve even smaller scales. Therefore, general circulation models (GCMs) and chemistry climate models (CCMs) usually parametrize the effect of gravity waves on the global circulation. These parametrizations are very simplified. For this reason, comparisons with global observations of gravity waves are needed for an improvement of parametrizations and an alleviation of model biases. We present a gravity wave climatology based on atmospheric infrared limb emissions observed by satellite (GRACILE). GRACILE is a global data set of gravity wave distributions observed in the stratosphere and the mesosphere by the infrared limb sounding satellite instruments High Resolution Dynamics Limb Sounder (HIRDLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER). Typical distributions (zonal averages and global maps) of gravity wave vertical wavelengths and along-track horizontal wavenumbers are provided, as well as gravity wave temperature variances, potential energies and absolute momentum fluxes. This global data set captures the typical seasonal variations of these parameters, as well as their spatial variations. The GRACILE data set is suitable for scientific studies, and it can serve for comparison with other instruments (ground-based, airborne, or other satellite instruments) and for comparison with gravity wave distributions, both resolved and parametrized, in GCMs and CCMs. The GRACILE data set is available as supplementary data at https://doi.org/10.1594/PANGAEA.879658" target="_blank">https://doi.org/10.1594/PANGAEA.879658.

INTERPRETATION OF AIRBORNE ELECTROMAGNETIC AND MAGNETIC DATA IN THE 600 AREA

Energy Technology Data Exchange (ETDEWEB)

CUMMINS GD

2010-11-11

As part of the 200-PO-1 Phase I geophysical surveys, Fugro Airborne Surveys was contracted to collect airborne electromagnetic (EM) and magnetic surveys of the Hanford Site 600 Area. Two helicopter survey systems were used with the HeliGEOTEM{reg_sign} time domain portion flown between June 19th and June 20th, 2008, and the RESOLVE{reg_sign} frequency domain portion was flown from June 29th to July 1st, 2008. Magnetic data were acquired contemporaneously with the electromagnetic surveys using a total-field cesium vapor magnetometer. Approximately 925 line kilometers (km) were flown using the HeliGEOTEM{reg_sign} II system and 412 line kilometers were flown using the RESOLVE{reg_sign} system. The HeliGEOTEM system has an effective penetration of roughly 250 meters into the ground and the RESOLVE system has an effective penetration of roughly 60 meters. Acquisition parameters and preliminary results are provided in SGW-39674, Airborne Electromagnetic Survey Report, 200-PO-1 Groundwater Operable Unit, 600 Area, Hanford Site. Airborne data are interpreted in this report in an attempt to identify areas of likely preferential groundwater flow within the aquifer system based on the presence of paleochannels or fault zones. The premise for the interpretation is that coarser-grained intervals have filled in scour channels created by episodic catastrophic flood events during the late Pleistocene. The interpretation strategy used the magnetic field anomaly data and existing bedrock maps to identify likely fault or lineament zones. Combined analysis of the magnetic, 60-Hz noise monitor, and flight-altitude (radar) data were used to identify zones where EM response is more likely due to cultural interference and or bedrock structures. Cross-sectional and map view presentations of the EM data were used to identify more electrically resistive zones that likely correlate with coarser-grained intervals. The resulting interpretation identifies one major northwest-southeast trending

Geophysical investigation using gravity data in Kinigi geothermal field, northwest Rwanda

Science.gov (United States)

Uwiduhaye, Jean d.'Amour; Mizunaga, Hideki; Saibi, Hakim

2018-03-01

A land gravity survey was carried out in the Kinigi geothermal field, Northwest Rwanda using 184 gravity stations during August and September, 2015. The aim of the gravity survey was to understand the subsurface structure and its relation to the observed surface manifestations in the study area. The complete Bouguer Gravity anomaly was produced with a reduction density of 2.4 g/cm3. Bouguer anomalies ranging from -52 to -35 mGals were observed in the study area with relatively high anomalies in the east and northwest zones while low anomalies are observed in the southwest side of the studied area. A decrease of 17 mGals is observed in the southwestern part of the study area and caused by the low-density of the Tertiary rocks. Horizontal gradient, tilt angle and analytical signal methods were applied to the observed gravity data and showed that Mubona, Mpenge and Cyabararika surface springs are structurally controlled while Rubindi spring is not. The integrated results of gravity gradient interpretation methods delineated a dominant geological structure trending in the NW-SE, which is in agreement with the regional geological trend. The results of this gravity study will help aid future geothermal exploration and development in the Kinigi geothermal field.

Airborne gamma-ray spectrometer and magnetometer survey: Barrow Quadrangle, Alaska. Final report. Volume I

International Nuclear Information System (INIS)

1981-03-01

During the months of July-August 1980, Aero Service Division Western Geophysical Company of America conducted an airborne high sensitivity gamma-ray spectrometer and magnetometer survey over eleven (11) 3 0 x 1 0 and one (1) 4 0 x 1 0 NTMS quadrangles of the Alaskan North Slope. This report discusses the results obtained over the Barrow map area. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps, flight path maps, and computer printer maps. The histograms and the multiparameter profiles are presented with the anomaly maps and flight path map in a separate bound volume. Complete data listings of both the reduced single record and the reduced averaged record data are found in the back of this report. The format of the printout of the microfiches and the format of the data files delivered on magnetic tape are in accordance with the specifications of the BFEC 1200-C and are described in appendices F through L of this report

Interpretation of Airborne Radiometric and Magnetic Data in the ...

African Journals Online (AJOL)

Wadi Millaha area is located in the North Eastern Desert of Egypt. It has been systematically surveyed using airborne gamma-ray spectrometric and magnetic methods. In the present study, the identification of both uranium and thorium anomalies has been mainly based on examining a set of composite spectrometric ...

Development of snow water equivalent survey methods using airborne gamma measurements. Research progress, January 1975--September 1975 and suggested directions for future work

International Nuclear Information System (INIS)

Fritzsche, A.; Jupiter, C.

1975-01-01

This is a summary of the progress made during the period March 1975 through September 1975 on EG and G's support of the National Oceanic and Atmospheric Administration for development of airborne techniques for measurement of the water equivalent of snow and soil moisture. The work included a series of snow and soil moisture surveys and development of a new detector and data acquisition system. The status of this work is summarized here together with a review of plans for the immediate future

Gravity Anomalies Over The Gongola Arm, Upper Benue Trough ...

African Journals Online (AJOL)

A regional gravity survey of the Gongola Arm of the Benue trough was carried out with the aim of determining structures of interest. The results of the gravity interpretation showed that the area of study is characterized by negative Bouguer anomalies that trend in the NE-SW direction and range in value from -75 to -15 mGal ...

Hiding neutrino mass in modified gravity cosmologies

Energy Technology Data Exchange (ETDEWEB)

Bellomo, Nicola; Bellini, Emilio; Hu, Bin; Jimenez, Raul; Verde, Licia [ICC, University of Barcelona (UB-IEEC), Marti i Franques 1, 08028, Barcelona (Spain); Pena-Garay, Carlos, E-mail: nicola.bellomo@icc.ub.edu, E-mail: emilio.bellini@physics.ox.ac.uk, E-mail: binhu@icc.ub.edu, E-mail: raul.jimenez@icc.ub.edu, E-mail: penya@ific.uv.es, E-mail: liciaverde@icc.ub.edu [Instituto de Fisica Corpuscular, CSIC-UVEG, P.O. 22085, Valencia, 46071 (Spain)

2017-02-01

Cosmological observables show a dependence with the neutrino mass, which is partially degenerate with parameters of extended models of gravity. We study and explore this degeneracy in Horndeski generalized scalar-tensor theories of gravity. Using forecasted cosmic microwave background and galaxy power spectrum datasets, we find that a single parameter in the linear regime of the effective theory dominates the correlation with the total neutrino mass. For any given mass, a particular value of this parameter approximately cancels the power suppression due to the neutrino mass at a given redshift. The extent of the cancellation of this degeneracy depends on the cosmological large-scale structure data used at different redshifts. We constrain the parameters and functions of the effective gravity theory and determine the influence of gravity on the determination of the neutrino mass from present and future surveys.

Calibration of angle response of a NaI(Tl) airborne spectrometer to 137Cs and 60Co point sources on the ground

International Nuclear Information System (INIS)

Liu Xinhua; Zhang Yongxing; Gu Renkang; Shen Ensheng

1998-01-01

The angle response function F(φ,θ) is a basic calibration of airborne spectrometers in airborne surveying for nuclear emergency monitoring. The author describes the method and results of angle response function calibration of a NaI(Tl) airborne spectrometer for 137 Cs and 60 Co point sources on the ground, with less than 20% uncertainty. By using the results, the calibration factors of the NaI(Tl) airborne spectrometer fixed in Yun-5 plane at different flying heights are calculated by numerical integral method for 137 Cs uniform area source on ground surface, with less than 25% uncertainty. The minimum detection limits (L D ) are calculated at 90 m and 120 m flying heights in the range of over Shijiazhuang airborne surveying for 137 Cs uniform area source on ground surface to be 3.83 and 5.62 kBq/m 2 , respectively

Airborne Compositae dermatitis

DEFF Research Database (Denmark)

Christensen, Lars Porskjær; Jakobsen, Henrik Byrial; Paulsen, E.

1999-01-01

The air around intact feverfew (Tanacetum parthenium) plants was examined for the presence of airborne parthenolide and other potential allergens using a high-volume air sampler and a dynamic headspace technique. No particle-bound parthenolide was detected in the former. Among volatiles emitted f...... for airborne Compositae dermatitis. Potential allergens were found among the emitted monoterpenes and their importance in airborne Compositae dermatitis is discussed....

A gravity survey of parts of quadrangles 26E, 26F, 27E, and 27F, northeastern Arabian Shield, Kingdom of Saudi Arabia

Science.gov (United States)

Miller, C.H.; Showail, A.A.; Kane, M.F.; Khoja, I.A.; Al Ghandi, S. A.

1989-01-01

A gravity survey using nearly 800 stations was conducted over an area of about 13,400 km2 located in the northeast part of the Arabian Shield. The stations were set on spot elevations of relative high density and shown on high-quality l:50,000-scale topographic base maps.

Airborne gamma-ray spectrometer and magnetometer survey: Forsyth quadrangle, Round Up quadrangle, Hardin quadrangle (Montana), Sheridan quadrangle, (Wyoming). Final report

International Nuclear Information System (INIS)

1981-01-01

An airborne combined radiometric and magnetic survey was performed for the Department of Energy (DOE) over the area covered by the Forsyth, Hardin, and Sheridan, and Roundup, 1:250,000 National Topographic Map Series (NTMS), quadrangle maps. The survey was part of DOE's National Uranium Resource Evaluation (NURE) program. Data were collected by a helicopter equipped with a gamma-ray spectrometer with a large crystal volume, and with a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration Pads and the Lake Mead Dynamic Test Range. Data quality was ensured during the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. The anomalies were interpreted and an interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data collection procedures, the data processing procedures, the data presentation, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

Lithologic boundaries from gravity and magnetic anomalies over ...

Indian Academy of Sciences (India)

Dalma volcanics (DVs) has intruded the older Singhbhum Group of Metapelites. Despite DVs being rich in mineralisation, its boundaries are not clearly demarcated. Gravity and magnetic surveys have been attempted for mapping the boundaries in DVs. These surveys were made in the northern fringeof the DVs over an ...

Strapdown Airborne Gravimetry Quality Assessment Method Based on Single Survey Line Data: A Study by SGA-WZ02 Gravimeter

Science.gov (United States)

Wu, Meiping; Cao, Juliang; Zhang, Kaidong; Cai, Shaokun; Yu, Ruihang

2018-01-01

Quality assessment is an important part in the strapdown airborne gravimetry. Root mean square error (RMSE) evaluation method is a classical way to evaluate the gravimetry quality, but classical evaluation methods are preconditioned by extra flight or reference data. Thus, a method, which is able to largely conquer the premises of classical quality assessment methods and can be used in single survey line, has been developed in this paper. According to theoretical analysis, the method chooses the stability of two horizontal attitude angles, horizontal specific force and vertical specific force as the determinants of quality assessment method. The actual data, collected by SGA-WZ02 from 13 flights 21 lines in certain survey, was used to build the model and elaborate the method. To substantiate the performance of the quality assessment model, the model is applied in extra repeat line flights from two surveys. Compared with internal RMSE, standard deviation of assessment residuals are 0.23 mGal and 0.16 mGal in two surveys, which shows that the quality assessment method is reliable and stricter. The extra flights are not necessary by specially arranging the route of flights. The method, summarized from SGA-WZ02, is a feasible approach to assess gravimetry quality using single line data and is also suitable for other strapdown gravimeters. PMID:29373535

Feasibility study of geophysical survey in Uruguay 07.05 - 02.06.1987

International Nuclear Information System (INIS)

Eberle, D.

1987-01-01

The aim of this report has been carried out an airborne magnetic and radiometric survey that would be followed by an interpretation stage to delineate and area of increased mineral potential where an airborne electromagnetic survey might be held in further stage.

Weak lensing probes of modified gravity

International Nuclear Information System (INIS)

Schmidt, Fabian

2008-01-01

We study the effect of modifications to general relativity on large-scale weak lensing observables. In particular, we consider three modified gravity scenarios: f(R) gravity, the Dvali-Gabadadze-Porrati model, and tensor-vector-scalar theory. Weak lensing is sensitive to the growth of structure and the relation between matter and gravitational potentials, both of which will in general be affected by modified gravity. Restricting ourselves to linear scales, we compare the predictions for galaxy-shear and shear-shear correlations of each modified gravity cosmology to those of an effective dark energy cosmology with the same expansion history. In this way, the effects of modified gravity on the growth of perturbations are separated from the expansion history. We also propose a test which isolates the matter-potential relation from the growth factor and matter power spectrum. For all three modified gravity models, the predictions for galaxy and shear correlations will be discernible from those of dark energy with very high significance in future weak lensing surveys. Furthermore, each model predicts a measurably distinct scale dependence and redshift evolution of galaxy and shear correlations, which can be traced back to the physical foundations of each model. We show that the signal-to-noise for detecting signatures of modified gravity is much higher for weak lensing observables as compared to the integrated Sachs-Wolfe effect, measured via the galaxy-cosmic microwave background cross-correlation.

Connected magma plumbing system between Cerro Negro and El Hoyo Complex, Nicaragua revealed by gravity survey

Science.gov (United States)

MacQueen, Patricia; Zurek, Jeffrey; Williams-Jones, Glyn

2016-11-01

Cerro Negro, near León, Nicaragua is a young, relatively small basaltic cinder cone volcano that has been unusually active during its short lifespan. Multiple explosive eruptions have deposited significant amounts of ash on León and the surrounding rural communities. While a number of studies investigate the geochemistry and stress regime of the volcano, subsurface structures have only been studied by diffuse soil gas surveys. These studies have raised several questions as to the proper classification of Cerro Negro and its relation to neighboring volcanic features. To address these questions, we collected 119 gravity measurements around Cerro Negro volcano in an attempt to delineate deep structures at the volcano. The resulting complete Bouguer anomaly map revealed local positive gravity anomalies (wavelength 0.5 to 2 km, magnitude +4 mGal) and regional positive (10 km wavelength, magnitudes +10 and +8 mGal) and negative (12 and 6 km wavelength, magnitudes -18 and -13 mGal) Bouguer anomalies. Further analysis of these gravity data through inversion has revealed both local and regional density anomalies that we interpret as intrusive complexes at Cerro Negro and in the Nicaraguan Volcanic Arc. The local density anomalies at Cerro Negro have a density of 2700 kg m-3 (basalt) and are located between -250 and -2000 m above sea level. The distribution of recovered density anomalies suggests that eruptions at Cerro Negro may be tapping an interconnected magma plumbing system beneath El Hoyo, Cerro La Mula, and Cerro Negro, and more than seven other proximal volcanic features, implying that Cerro Negro should be considered the newest cone of a Cerro Negro-El Hoyo volcanic complex.

Airborne Video Surveillance

National Research Council Canada - National Science Library

Blask, Steven

2002-01-01

The DARPA Airborne Video Surveillance (AVS) program was established to develop and promote technologies to make airborne video more useful, providing capabilities that achieve a UAV force multiplier...

Accuracy evaluation of pendulum gravity measurements of Robert von Sterneck

Directory of Open Access Journals (Sweden)

Alena Pešková

2015-06-01

Full Text Available The accuracy of first pendulum gravity measurements in the Czech territory was determined using both original surveying notebooks of Robert Daublebsky von Sterneck and modern technologies. Since more accurate methods are used for gravity measurements nowadays, our work is mostly important from the historical point of view. In previous  works, the accuracy of Sterneck’s gravity measurements was determined using only a small dataset. Here we process all Sterneck’s measurements from the Czech territory (a dataset ten times larger than in the previous works, and we complexly assess the accuracy of these measurements. Locations of the measurements were found with the help of original notebooks. Gravity in the site was interpolated using actual gravity models. Finally, the accuracy of Sterneck’s measurements was evaluated as the difference between the measured and interpolated gravity.

Airborne gamma anomalies in the Elbe Valley near Koenigstein, Germany - Origin and variation with time

International Nuclear Information System (INIS)

Ruhrmann, G.; Schmeling, B.; Schauer, M.; Gatzweiler, R.

1997-01-01

In 1982, an airborne gamma spectrometer survey was undertaken by SDAG WISMUT which was directed at the detection of further uranium mineralization in Saxony and Thuringia. Anomalies outlined along the Elbe river near the existing Koenigstein uranium mine were attributed to one or a combination of the following causes: radioactive residues from uranium processing facilities located upstream, temporary accumulation of Rn-decay products attached to dust particles in the atmosphere at the time of the survey, and radioactive waters emerging from uraniferous rocks along tectonic structures. In 1994, WISMUT GmbH re-evaluated the survey to determine the need for implementing cleanup measures. Subsequent to the verification of the original airborne data, ground surveys were undertaken that included gamma spectrometry, percussion probing and river sediment sampling. The new results did not confirm the magnitude of most of the 1982 airborne anomalies. The general decline of the radioactivity pointed out by the 1994 ground measurements is interpreted to be a result of the partial erosion and dilution of radionuclides in fluvial sediments as well as burial by additional river sediments since. Additional anomalous copper and zinc concentrations are attributed to sources other than mining. The ground follow-up delineated a new anomalous zone that is caused by radionuclides discharged with treated process and mine water. It is the only area, which may require further investigations and possible remedial action. (author)

Cosmological acceleration. Dark energy or modified gravity?

International Nuclear Information System (INIS)

Bludman, S.

2006-05-01

We review the evidence for recently accelerating cosmological expansion or ''dark energy'', either a negative pressure constituent in General Relativity (Dark Energy) or modified gravity (Dark Gravity), without any constituent Dark Energy. If constituent Dark Energy does not exist, so that our universe is now dominated by pressure-free matter, Einstein gravity must be modified at low curvature. The vacuum symmetry of any Robertson-Walker universe then characterizes Dark Gravity as low- or high-curvature modifications of Einstein gravity. The dynamics of either kind of ''dark energy'' cannot be derived from the homogeneous expansion history alone, but requires also observing the growth of inhomogeneities. Present and projected observations are all consistent with a small fine tuned cosmological constant, but also allow nearly static Dark Energy or gravity modified at cosmological scales. The growth of cosmological fluctuations will potentially distinguish between static and ''dynamic'' ''dark energy''. But, cosmologically distinguishing the Concordance Model ΛCDM from modified gravity will require a weak lensing shear survey more ambitious than any now projected. Dvali-Gabadadze-Porrati low-curvature modifications of Einstein gravity may also be detected in refined observations in the solar system (Lue and Starkman) or at the intermediate Vainstein scale (Iorio) in isolated galaxy clusters. Dark Energy's epicyclic character, failure to explain the original Cosmic Coincidence (''Why so small now?'') without fine tuning, inaccessibility to laboratory or solar system tests, along with braneworld theories, now motivate future precision solar system, Vainstein-scale and cosmological-scale studies of Dark Gravity. (Orig.)

Cosmological acceleration. Dark energy or modified gravity?

Energy Technology Data Exchange (ETDEWEB)

Bludman, S

2006-05-15

We review the evidence for recently accelerating cosmological expansion or ''dark energy'', either a negative pressure constituent in General Relativity (Dark Energy) or modified gravity (Dark Gravity), without any constituent Dark Energy. If constituent Dark Energy does not exist, so that our universe is now dominated by pressure-free matter, Einstein gravity must be modified at low curvature. The vacuum symmetry of any Robertson-Walker universe then characterizes Dark Gravity as low- or high-curvature modifications of Einstein gravity. The dynamics of either kind of ''dark energy'' cannot be derived from the homogeneous expansion history alone, but requires also observing the growth of inhomogeneities. Present and projected observations are all consistent with a small fine tuned cosmological constant, but also allow nearly static Dark Energy or gravity modified at cosmological scales. The growth of cosmological fluctuations will potentially distinguish between static and ''dynamic'' ''dark energy''. But, cosmologically distinguishing the Concordance Model {lambda}CDM from modified gravity will require a weak lensing shear survey more ambitious than any now projected. Dvali-Gabadadze-Porrati low-curvature modifications of Einstein gravity may also be detected in refined observations in the solar system (Lue and Starkman) or at the intermediate Vainstein scale (Iorio) in isolated galaxy clusters. Dark Energy's epicyclic character, failure to explain the original Cosmic Coincidence (''Why so small now?'') without fine tuning, inaccessibility to laboratory or solar system tests, along with braneworld theories, now motivate future precision solar system, Vainstein-scale and cosmological-scale studies of Dark Gravity. (Orig.)

Ground-Truthing of Airborne LiDAR Using RTK-GPS Surveyed Data in Coastal Louisiana's Wetlands

Science.gov (United States)

Lauve, R. M.; Alizad, K.; Hagen, S. C.

2017-12-01

Airborne LiDAR (Light Detection and Ranging) data are used by engineers and scientists to create bare earth digital elevation models (DEM), which are essential to modeling complex coastal, ecological, and hydrological systems. However, acquiring accurate bare earth elevations in coastal wetlands is difficult due to the density of marsh grasses that prevent the sensors reflection off the true ground surface. Previous work by Medeiros et al. [2015] developed a technique to assess LiDAR error and adjust elevations according to marsh vegetation density and index. The aim of this study is the collection of ground truth points and the investigation on the range of potential errors found in existing LiDAR datasets within coastal Louisiana's wetlands. Survey grids were mapped out in an area dominated by Spartina alterniflora and a survey-grade Trimble Real Time Kinematic (RTK) GPS device was employed to measure bare earth ground elevations in the marsh system adjacent to Terrebonne Bay, LA. Elevations were obtained for 20 meter-spaced surveyed grid points and were used to generate a DEM. The comparison between LiDAR derived and surveyed data DEMs yield an average difference of 23 cm with a maximum difference of 68 cm. Considering the local tidal range of 45 cm, these differences can introduce substantial error when the DEM is used for ecological modeling [Alizad et al., 2016]. Results from this study will be further analyzed and implemented in order to adjust LiDAR-derived DEMs closer to their true elevation across Louisiana's coastal wetlands. ReferencesAlizad, K., S. C. Hagen, J. T. Morris, S. C. Medeiros, M. V. Bilskie, and J. F. Weishampel (2016), Coastal wetland response to sea-level rise in a fluvial estuarine system, Earth's Future, 4(11), 483-497, 10.1002/2016EF000385. Medeiros, S., S. Hagen, J. Weishampel, and J. Angelo (2015), Adjusting Lidar-Derived Digital Terrain Models in Coastal Marshes Based on Estimated Aboveground Biomass Density, Remote Sensing, 7

Airborne gamma-radiation snow water-equivalent and soil-moisture measurements and satellite areal extent of snow-cover measurements. A user's guide. Version 3.0

International Nuclear Information System (INIS)

Carroll, T.; Allen, M.

1988-01-01

The National Remote Sensing Hydrology Program is managed by the Office of Hydrology and consists of the Airborne Snow Survey Section and the Satellite Hydrology Section. The Airborne Snow Survey Section makes airborne snow water-equivalent and soil-moisture measurements over large areas of the country subject to a severe and chronic snowmelt flooding threat. The User's Guide is intended primarily to provide field hydrologists with some background on the technical and administrative aspects of the National Remote Sensing Hydrology Program. The guide summarizes the techniques and procedures used to make and distribute real-time, operational airborne snow water-equivalent measurements and satellite areal extent of snow-cover measurements made over large areas of the country. The current airborne and satellite databases are summarized, and procedures to access the real-time observations through both AFOS and through a commercial, electronic bulletin board system are given in the appendices

Putting the Scanning Laser Environmental Airborne Fluorosensor through its paces : initial test results

International Nuclear Information System (INIS)

Brown, C.E.; Fingas, M.F.; Mullin, J.V.; Dick, R.; Giroud, C.

1998-01-01

The development and construction of a remote sensing system used to detect and map oil and related petroleum products in complex marine and shoreline environments was reviewed. The Scanning Laser Environmental Airborne Fluorosensor (SLEAF) system will be integrated into Environment Canada's DC-3 aircraft and will be undergoing extensive testing to verify its functionality in an airborne environment. Laser fluorosensors are the only sensors that can successfully detect oil in most environments including snow and ice. One of the roles of SLEAF will be to confirm or reject suspected oil contamination sites that have been targeted by infrared or visible spectral cameras. The ability of the SLEAF system to detect, classify and estimate oil coverage has been tested using a total of twenty-one oils ranging from light refined crude through to heavy refined oils. The aromatic content of the oils varied between 13 and 52 per cent and the API gravities of the oils tested varied from 11.9 to 48.6. 10 refs., 2 tabs., 2 figs

An airborne gamma ray survey of parts of SW Scotland in February 1993. Final Report

International Nuclear Information System (INIS)

Sanderson, D.C.W.; Allyson, J.D.; Tyler, A.N.; Ni Riain, S.; Murphy, S.

1994-01-01

An airborne gamma ray survey was conducted for the Scottish Office Environment Department of coastal and inland parts of SW Scotland to define existing background levels, to locate features worthy of further attention, and to demonstrate the emergency response capabilities of radiometric methods. Coastal areas were surveyed with 500 m line spacing. Inland areas were specified to 2 km line spacing, however it was possible to achieve 1 km line spacing in the majority of the inland zone. The radiometric maps show clearly the distributions of each individual nuclide and indicate the contribution which individual localised features make to the overall gamma ray dose rate. Naturally occurring nuclides reflect the underlying geological and geomorphological contexts of the landscapes. The main granite intrusions, most notably at Cairnsmore of Fleet, the Loch Doon Granodiorite, Glencairn of Carsphairn, the Dalbeattie granite, and Criffel Pluton are readily visible in 40 K, 214 Bi and 208 Tl maps, and control their local radiation environments. A number of areas of enhanced 214 Bi, which may reflect radon potential, were noted. A transient radon associated 214 Bi signal was observed on the west of the Wigtown peninsular during the survey. Examination of spectral data in the vicinity Dundrennan has confirmed that there is no evidence of widespread terrestrial contamination arising from the use of depleted uranium projectiles on the range. The 137 Cs map indicates the environmental distribution of this nuclide in considerable detail. Levels of 137 Cs range from approximately 2 kBq m -2 , a level consistent with global weapons' testing fallout, from 2-40 kBq m -2 on terrestrial sites affected by deposition from the Chernobyl accident, and from 40 kBq m -2 to over 200 kBq m -2 on tide washed pastures which have accumulated marine sediments from the Irish sea. (author)

King George Island ice cap geometry updated with airborne GPR measurements

Directory of Open Access Journals (Sweden)

M. Rückamp

2012-07-01

Full Text Available Ice geometry is a mandatory requirement for numerical modelling purposes. In this paper we present a consistent data set for the ice thickness, the bedrock topography and the ice surface topography of the King George Island ice cap (Arctowski icefield and the adjacent central part. The new data set is composed of ground based and airborne ground penetrating radar (GPR and differential GPS (DGPS measurements, obtained during several field campaigns. Blindow et al. (2010 already provided a comprehensive overview of the ground based measurements carried out in the safely accessible area of the ice cap. The updated data set incorporates airborne measurements in the heavily crevassed coastal areas. Therefore, in this paper special attention is paid to the airborne measurements by addressing the instrument used, survey procedure, and data processing in more detail. In particular, the inclusion of airborne GPR measurements with the 30 MHz BGR-P30-System developed at the Institute of Geophysics (University of Münster completes the picture of the ice geometry substantially. The compiled digital elevation model of the bedrock shows a rough, highly variable topography with pronounced valleys, ridges, and troughs. Mean ice thickness is 240 ± 6 m, with a maximum value of 422 ± 10 m in the surveyed area. Noticeable are bounded areas in the bedrock topography below sea level where marine based ice exists. The provided data set is required as a basis for future monitoring attempts or as input for numerical modelling experiments. The data set is available from the PANGAEA database at http://dx.doi.org/10.1594/PANGAEA.770567.

Gravity in minesmdashAn investigation of Newton's law

International Nuclear Information System (INIS)

Holding, S.C.; Stacey, F.D.; Tuck, G.J.

1986-01-01

The evidence that the value of the Newtonian gravitational constant G inferred from measurements of gravity g in mines and boreholes is of order 1% higher than the laboratory value is hardened with new and improved data from two mines in northwest Queensland. Surface-gravity surveys and more than 14 000 bore-core density values have been used to establish density structures for the mines, permitting full three-dimensional inversion to obtain G. Further constraint is imposed by requiring that the density structure give the same value of G for several vertical profiles of g, separated by hundreds of meters. The only residual doubt arises from the possibility of bias by an anomalous regional gravity gradient. Neither measurements of gravity gradient above ground level (in tall chimneys) nor surface surveys are yet adequate to remove this doubt, but the coincidence of conclusions derived from mine data obtained in different parts of the world makes such an anomaly appear an improbable explanation. If Newton's law is modified by adding a Yukawa term to the gravitational potential of a point mass m at distance r, V = -(G/sub infinity/m/r)(1+αe/sup -r/lambda/), then the mine data provide a mutual constraint on the values of α and lambda, although they cannot be determined independently. Our results give αroughly-equal-0.0075 if lambda or =10 4 m, with intermediate values of α between these ranges, but values greater than α = -0.010, lambda = 800 m appear to be disallowed by a comparison of satellite and land-surface estimates of gravity

Mercury soil surveys: a good reconnaissance tool

Energy Technology Data Exchange (ETDEWEB)

Stone, C.; Ruscetta, C.A.; Foley, D. (eds.)

1981-05-01

Three examples of mercury soil surveys are discussed, along with the gravity data. An excellent correlation was found in southern Arizona between buried structures revealed by gravity and mercury soil surveys. The advantages of the latter over the former as a reconnaissance tool are listed. (MHR)

Capability assessment and challenges for quantum technology gravity sensors for near surface terrestrial geophysical surveying

Science.gov (United States)

Boddice, Daniel; Metje, Nicole; Tuckwell, George

2017-11-01

Geophysical surveying is widely used for the location of subsurface features. Current technology is limited in terms of its resolution (thus size of features it can detect) and penetration depth and a suitable technique is needed to bridge the gap between shallow near surface investigation using techniques such as EM conductivity mapping and GPR commonly used to map the upper 5 m below ground surface, and large features at greater depths detectable using conventional microgravity (> 5 m below ground surface). This will minimise the risks from unknown features buried in and conditions of the ground during civil engineering work. Quantum technology (QT) gravity sensors potentially offer a step-change in technology for locating features which lie outside of the currently detectable range in terms of size and depth, but that potential is currently unknown as field instruments have not been developed. To overcome this, a novel computer simulation was developed for a large range of different targets of interest. The simulation included realistic noise modelling of instrumental, environmental and location sources of noise which limit the accuracy of current microgravity measurements, in order to assess the potential capability of the new QT instruments in realistic situations and determine some of the likely limitations on their implementation. The results of the simulations for near surface features showed that the new technology is best employed in a gradiometer configuration as opposed to the traditional single sensor gravimeter used by current instruments due to the ability to suppress vibrational environmental noise effects due to common mode rejection between the sensors. A significant improvement in detection capability of 1.5-2 times was observed, putting targets such as mineshafts into the detectability zone which would be a major advantage for subsurface surveying. Thus this research, for the first time, has demonstrated clearly the benefits of QT gravity

Implementing gravity method on geological contacts in Bukit Bunuh, Lenggong, Perak (Malaysia)

International Nuclear Information System (INIS)

Hidayah, I N E; Saad, Rosli; Nordiana, M M; Azwin, I N; Bery, Andy Anderson; Saidin, Mokhtar

2015-01-01

Using gravity method, a study of responses of different geological settings towards gravity was conducted in Bukit Bunuh, Lenggong, Perak (Malaysia). Gravity method provides different responses towards different rock types depending on the rock density. The survey area cover an area of 12 km 2 , with a total 404 survey stations with stations interval of approximately 50 m and 500 m. The Bouguer anomaly map identifies the shallow granite rock with a value of -6 to -10.5 mGal while shallow limestone is -11 to -15 mGal. The sediment/overburden was identified with value of < -15.5 mGal. Few fractures are also identified and the boundary between limestone and granite rocks identified at the north part of the study area

Radiometric, magnetic, and gravity study of the Quixadá batholith, central Ceará domain (NE Brazil): evidence for Pan-African/Brasiliano extension-controlled emplacement

Science.gov (United States)

Lopes de Castro, David; Mariano Gomes Castelo Branco, Raimundo; Martins, Guttenberg; Araújo de Castro, Neivaldo

2002-10-01

A geophysical survey was conducted in the central Ceará domain of the Borborema Province (NE Brazil). The aim of this investigation was to find geophysical evidence for the emplacement of the Quixadá batholith, which is a granitic body probably situated in the local extensional site in the oblique collisional regime of the Pan-African/Brasiliano collage. Remote sensing and airborne geophysical data provided information on the regional deformation that affected the intrusion and surrounding country rocks. In addition, a gravity study was used to determine the three-dimensional geometry and constrain the emplacement model of the Quixadá granite at depth. The trajectories of structural and magnetic lineaments suggest that the regional deformation is strongly influenced by dextral transcurrent movements of the major shear zones. The batholith, which shows an unusual positive gravity anomaly and a low U counts, displays a subhorizontal floor with several gently dipping areas, which are interpreted as magma feeder channels. The 2300 m thick root zones are roughly aligned with NE-SW-trending shear zones. Finally, the internal architecture of the pluton suggests that the Quixadá batholith was emplaced in a dilational shear zone tip area at the north end of Quixeramobim shear zone.

A Combined Gravity Compensation Method for INS Using the Simplified Gravity Model and Gravity Database.

Science.gov (United States)

Zhou, Xiao; Yang, Gongliu; Wang, Jing; Wen, Zeyang

2018-05-14

In recent decades, gravity compensation has become an important way to reduce the position error of an inertial navigation system (INS), especially for a high-precision INS, because of the extensive application of high precision inertial sensors (accelerometers and gyros). This paper first deducts the INS's solution error considering gravity disturbance and simulates the results. Meanwhile, this paper proposes a combined gravity compensation method using a simplified gravity model and gravity database. This new combined method consists of two steps all together. Step 1 subtracts the normal gravity using a simplified gravity model. Step 2 first obtains the gravity disturbance on the trajectory of the carrier with the help of ELM training based on the measured gravity data (provided by Institute of Geodesy and Geophysics; Chinese Academy of sciences), and then compensates it into the error equations of the INS, considering the gravity disturbance, to further improve the navigation accuracy. The effectiveness and feasibility of this new gravity compensation method for the INS are verified through vehicle tests in two different regions; one is in flat terrain with mild gravity variation and the other is in complex terrain with fierce gravity variation. During 2 h vehicle tests, the positioning accuracy of two tests can improve by 20% and 38% respectively, after the gravity is compensated by the proposed method.

Weakening gravity on redshift-survey scales with kinetic matter mixing

Energy Technology Data Exchange (ETDEWEB)

D' Amico, Guido [Theoretical Physics Department, CERN, Geneva (Switzerland); Huang, Zhiqi [School of Physics and Astronomy, Sun Yat-Sen University, 135 Xingang Xi Road, 510275, Guangzhou (China); Mancarella, Michele; Vernizzi, Filippo [CEA, IPhT, CNRS, URA-2306, 91191 Gif-sur-Yvette cédex (France)

2017-02-01

We explore general scalar-tensor models in the presence of a kinetic mixing between matter and the scalar field, which we call Kinetic Matter Mixing. In the frame where gravity is de-mixed from the scalar this is due to disformal couplings of matter species to the gravitational sector, with disformal coefficients that depend on the gradient of the scalar field. In the frame where matter is minimally coupled, it originates from the so-called beyond Horndeski quadratic Lagrangian. We extend the Effective Theory of Interacting Dark Energy by allowing disformal coupling coefficients to depend on the gradient of the scalar field as well. In this very general approach, we derive the conditions to avoid ghost and gradient instabilities and we define Kinetic Matter Mixing independently of the frame metric used to described the action. We study its phenomenological consequences for a ΛCDM background evolution, first analytically on small scales. Then, we compute the matter power spectrum and the angular spectra of the CMB anisotropies and the CMB lensing potential, on all scales. We employ the public version of COOP, a numerical Einstein-Boltzmann solver that implements very general scalar-tensor modifications of gravity. Rather uniquely, Kinetic Matter Mixing weakens gravity on short scales, predicting a lower σ{sub 8} with respect to the ΛCDM case. We propose this as a possible solution to the tension between the CMB best-fit model and low-redshift observables.

Principal facts for about 16,000 gravity stations in the Nevada Test Site and vicinity

International Nuclear Information System (INIS)

Harris, R.N.; Ponce, D.A.; Oliver, H.W.; Healey, D.L.

1989-01-01

The Nevada Test Site (NTS) and vicinity includes portions of the Goldfield, Caliente, Death Valley, and Las Vegas. This report documents and consolidates previously published and recently compiled gravity data to establish a gravity data base of about 16,000 stations for the NTS and vicinity. While compiling data sets, redundant stations and stations having doubtful locations or gravity values were excluded. Details of compiling the gravity data sets are discussed in later sections. Where feasible, an accuracy code has been assigned to each station so that the accuracy or reliability of each station can be evaluated. This data base was used in preparing complete Bouguer and isostatic gravity maps of the NTS and vicinity. Since publication of the complete Bouguer gravity map, additional data were incorporated into the isostatic gravity map. Gravity data were compiled from five sources: 14,183 stations from the US Geological Survey (USGS), 326 stations from Exploration Data Consultants (EDCON) of Denver, Colorado, 906 stations from the Los Alamos National Laboratory (LANL), 212 stations from the University of Texas at Dallas (UTD), and 48 stations from the Defense Mapping Agency (DMA). This investigation is an effort to study several areas for potential storage of high-level radioactive waste. Gravity stations established under YMP are shown. The objective of this gravity survey was to explore for the presence of plutons. This volume contains only compiled data

Principal facts for about 16,000 gravity stations in the Nevada Test Site and vicinity

International Nuclear Information System (INIS)

Harris, R.N.; Ponce, D.A.; Oliver, H.W.; Healey, D.L.

1989-01-01

The Nevada Test Site (NTS) and vicinity includes portions of the Goldfield, Caliente, Death Valley, and Las Vegas. This report documents and consolidates previously published and recently compiled gravity data to establish a gravity data base of about 16,000 stations for the NTS and vicinity. While compiling data sets, redundant stations and stations having doubtful locations or gravity values were excluded. Details of compiling the gravity data sets are discussed in later sections. Where feasible, an accuracy code has been assigned to each station so that the accuracy or reliability of each station can be evaluated. This data base was used in preparing complete Bouguer and isostatic gravity maps of the NTS and vicinity. Since publication of the complete Bouguer gravity map, additional data were incorporated into the isostatic gravity map. Gravity data were compiled from five sources: 14,183 stations from the US Geological Survey (USGS), 326 stations from Exploration Data Consultants (EDCON) of Denver, Colorado, 906 stations from the Los Alamos National Laboratory (LANL), 212 stations from the University of Texas at Dallas (UTD), and 48 stations from the Defense Mapping Agency (DMA). This investigation is an effort to study several areas for potential storage of high-level radioactive waste. Gravity stations established under YMP are shown. The objective of this gravity survey was to explore for the presence of plutons. 33 refs., 24 figs., 9 tabs

Gravity measurement, processing and evaluation: Test cases de Peel and South Limburg

Science.gov (United States)

Nohlmans, Ron

1990-05-01

A general overview of the process of the measurement and the adjustment of a gravity network and the computation of some output parameters of gravimetry, gravity values, gravity anomalies and mean block anomalies, is given. An overview of developments in gravimetry, globally and in the Netherlands, until now is given. The basic theory of relative gravity measurements is studied and a description of the most commonly used instrument, the LaCoste and Romberg gravimeter is given. The surveys done in the scope of this study are descibed. A more detailed impression of the adjustment procedure and the results of the adjustment are given. A closer look is taken at the more geophysical side of gravimetry: gravity reduction, the computation of anomalies and the correlation with elevation. The interpolation of gravity and the covariance of gravity anomalies are addressed.

Focus on quantum Einstein gravity Focus on quantum Einstein gravity

Science.gov (United States)

Ambjorn, Jan; Reuter, Martin; Saueressig, Frank

2012-09-01

time cosmology and the big bang, as well as TeV-scale gravity models testable at the Large Hadron Collider. On different grounds, Monte-Carlo studies of the gravitational partition function based on the discrete causal dynamical triangulations approach provide an a priori independent avenue towards unveiling the non-perturbative features of gravity. As a highlight, detailed simulations established that the phase diagram underlying causal dynamical triangulations contains a phase where the triangulations naturally give rise to four-dimensional, macroscopic universes. Moreover, there are indications for a second-order phase transition that naturally forms the discrete analog of the non-Gaussian fixed point seen in the continuum computations. Thus there is a good chance that the discrete and continuum computations will converge to the same fundamental physics. This focus issue collects a series of papers that outline the current frontiers of the gravitational asymptotic safety program. We hope that readers get an impression of the depth and variety of this research area as well as our excitement about the new and ongoing developments. References [1] Weinberg S 1979 General Relativity, an Einstein Centenary Survey ed S W Hawking and W Israel (Cambridge: Cambridge University Press)

Possible mechanisms by which electric fields from power lines might affect airborne particles harmful to health

International Nuclear Information System (INIS)

Swanson, J.; Jeffers, D.

1999-01-01

Power lines produce alternating electric fields and modify static electric fields in their vicinity. These electric fields, if large enough, can alter the concentration or transport of airborne particles (including particles harmful to health), for example by causing deposition of charged particles, polarisation of neutral particles, or by production of ions. It has been suggested that this could lead to adverse health effects being associated with power lines. Theoretical considerations and experimental evidence relevant to eight separate postulated mechanisms involving power lines and airborne particles are examined. On theoretical grounds, none should lead to any adverse health effect, primarily because the effects produced are very small and are swamped by air currents or by gravity, and because people spend limited time in the relevant conditions. The experimental evidence also weighs against any adverse health effects. Further, even if significant health effects were produced, they would be different from those suggested by existing epidemiology concerning power lines. (author)

Description and preliminary map, airborne electromagnetic survey of parts of Iron, Baraga, and Dickson counties, Michigan

Science.gov (United States)

Heran, William D.; Smith, Bruce D.

1980-01-01

The data presented herein is from an airborne electromagnetic INPUT* survey conducted by Geoterrex Limited of Canada for the U.S. Geological Survey. The survey area is located in the central part of the Upper Peninsula of Michigan, within parts of Iron, Baraga, and Dickinson Counties. The general area covered is between 46°00' and 46°30' latitude and 88°00' and 88°30' longitude (fig. 1).The INPUT survey was flown as part of a U.S. Geological Survey CUSMAP (Conterminous United States Mineral Appraisal Program) project focusing on the Iron River 2° quadrangle. The survey was flown in order to provide geophysical information which will aid in an integrated geological assessment of mineral potentials of this part of the Iron River 2 quadrangle. The flight-line spacing was chosen to maximize the aerial coverage without a loss of resolution of major lithologic and structural features. East-west flight lines were flown 400 feet above ground at 1/2-mile intervals. Aerial photos were used for navigation and the flight path was recorded on continuous-strip film. A continuously recording total field ground magnetic station was used to monitor variations in the Earth's magnetic field. One north-south line was flown to provide a tie for the magnetic data which was recorded simultaneously with the electromagnetic data by a sensor mounted in the tail of the aircraft. This report is one of two open-file reports. The map in the present report contains locations of the fiducial points, the flight lines, and preliminary locations of anomalies and conductive zones, all plotted on an air photomosaic. The latitude and longitude ticks marked on this map are only approximate due to distortion in air photos used to recover the flight line position. This map is preliminary and is not to be considered a final interpretation. The other report (Reran and Smith, 1980) contains a description of the instrument specifications, a copy of the ground station magnetic data, and a microfilm

Weak lensing: Dark Matter, Dark Energy and Dark Gravity

International Nuclear Information System (INIS)

Heavens, Alan

2009-01-01

In this non-specialist review I look at how weak lensing can provide information on the dark sector of the Universe. The review concentrates on what can be learned about Dark Matter, Dark Energy and Dark Gravity, and why. On Dark Matter, results on the confrontation of theoretical profiles with observation are reviewed, and measurements of neutrino masses discussed. On Dark Energy, the interest is whether this could be Einstein's cosmological constant, and prospects for high-precision studies of the equation of state are considered. On Dark Gravity, we consider the exciting prospects for future weak lensing surveys to distinguish General Relativity from extra-dimensional or other gravity theories.

Volumetric evolution of Surtsey, Iceland, from topographic maps and scanning airborne laser altimetry

Science.gov (United States)

Garvin, J.B.; Williams, R.S.; Frawley, J.J.; Krabill, W.B.

2000-01-01

The volumetric evolution of Surtsey has been estimated on the basis of digital elevation models derived from NASA scanning airborne laser altimeter surveys (20 July 1998), as well as digitized 1:5,000-scale topographic maps produced by the National Land Survey of Iceland and by Norrman. Subaerial volumes have been computed from co-registered digital elevation models (DEM's) from 6 July 1968, 11 July 1975, 16 July 1993, and 20 July 1998 (scanning airborne laser altimetry), as well as true surface area (above mean sea level). Our analysis suggests that the subaerial volume of Surtsey has been reduced from nearly 0.100 km3 on 6 July 1968 to 0.075 km3 on 20 July 1998. Linear regression analysis of the temporal evolution of Surtsey's subaerial volume indicates that most of its subaerial surface will be at or below mean sea-level by approximately 2100. This assumes a conservative estimate of continuation of the current pace of marine erosion and mass-wasting on the island, including the indurated core of the conduits of the Surtur I and Surtur II eruptive vents. If the conduits are relatively resistant to marine erosion they will become sea stacks after the rest of the island has become a submarine shoal, and some portions of the island could survive for centuries. The 20 July 1998 scanning laser altimeter surveys further indicate rapid enlargement of erosional canyons in the northeastern portion of the partial tephra ring associated with Surtur I. Continued airborne and eventually spaceborne topographic surveys of Surtsey are planned to refine the inter-annual change of its subaerial volume.

Satellite gravity gradient views help reveal the Antarctic lithosphere

Science.gov (United States)

Ferraccioli, F.; Ebbing, J.; Pappa, F.; Kern, M.; Forsberg, R.

2017-12-01

Here we present and analyse satellite gravity gradient signatures derived from GOCE and superimpose these on tectonic and bedrock topography elements, as well as seismically-derived estimates of crustal thickness for the Antarctic continent. The GIU satellite gravity component images the contrast between the thinner crust and lithosphere underlying the West Antarctic Rift System and the Weddell Sea Rift System and the thicker lithosphere of East Antarctica. The new images also suggest that more distributed wide-mode lithospheric and crustal extension affects both the Ross Sea Embayment and the less well known Ross Ice Shelf segment of the rift system. However, this pattern is less clear towards the Bellingshousen Embayment, indicating that the rift system narrows towards the southern edge of the Antarctic Peninsula. In East Antarctica, the satellite gravity data provides new views into the Archean to Mesoproterozoic Terre Adelie Craton, and clearly shows the contrast wrt to the crust and lithosphere underlying both the Wilkes Subglacial Basin to the east and the Sabrina Subglacial Basin to the west. This finding augments recent interpretations of aeromagnetic and airborne gravity data over the region, suggesting that the Mawson Continent is a composite lithospheric-scale entity, which was affected by several Paleoproterozoic and Mesoproterozoic orogenic events. Thick crust is imaged beneath the Transantarctic Mountains, the Terre Adelie Craton, the Gamburtsev Subglacial Mountains and also Eastern Dronning Maud Land, in particular beneath the recently proposed region of the Tonian Oceanic Arc Superterrane. The GIA and GIU components help delineate the edges of several of these lithospheric provinces. One of the most prominent lithospheric-scale features discovered in East Antarctica from satellite gravity gradient imaging is the Trans East Antarctic Shear Zone that separates the Gamburtsev Province from the Eastern Dronning Maud Land Province and appears to form the

A Gravity data along LARSE (Los Angeles Regional Seismic Experiment) Line II, Southern California

Science.gov (United States)

Wooley, R.J.; Langenheim, V.E.

2001-01-01

The U.S. Geological Survey conducted a detailed gravity study along part of the Los Angeles Regional Seismic Experiment (LARSE) transect across the San Fernando Basin and Transverse Ranges to help characterize the structure underlying this area. 249 gravity measurements were collected along the transect and to augment regional coverage near the profile. An isostatic gravity low of 50-60 mGal reflects the San Fernando-East Ventura basin. Another prominent isostatic gravity with an amplitude of 30 mGal marks the Antelope Valley basin. Gravity highs occur over the Santa Monica Mountains and the Transverse Ranges. The highest isostatic gravity values coincide with outcrops of Pelona schist.

Newtonian gravity in loop quantum gravity

OpenAIRE

Smolin, Lee

2010-01-01

We apply a recent argument of Verlinde to loop quantum gravity, to conclude that Newton's law of gravity emerges in an appropriate limit and setting. This is possible because the relationship between area and entropy is realized in loop quantum gravity when boundaries are imposed on a quantum spacetime.

On the Atmospheric Correction of Antarctic Airborne Hyperspectral Data

Directory of Open Access Journals (Sweden)

Martin Black

2014-05-01

Full Text Available The first airborne hyperspectral campaign in the Antarctic Peninsula region was carried out by the British Antarctic Survey and partners in February 2011. This paper presents an insight into the applicability of currently available radiative transfer modelling and atmospheric correction techniques for processing airborne hyperspectral data in this unique coastal Antarctic environment. Results from the Atmospheric and Topographic Correction version 4 (ATCOR-4 package reveal absolute reflectance values somewhat in line with laboratory measured spectra, with Root Mean Square Error (RMSE values of 5% in the visible near infrared (0.4–1 µm and 8% in the shortwave infrared (1–2.5 µm. Residual noise remains present due to the absorption by atmospheric gases and aerosols, but certain parts of the spectrum match laboratory measured features very well. This study demonstrates that commercially available packages for carrying out atmospheric correction are capable of correcting airborne hyperspectral data in the challenging environment present in Antarctica. However, it is anticipated that future results from atmospheric correction could be improved by measuring in situ atmospheric data to generate atmospheric profiles and aerosol models, or with the use of multiple ground targets for calibration and validation.

Hydrographic & Topographic LIDAR Acquisition, Northwest Coast, Washington State - Bathymetric Survey Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data were collected by the SHOALS-1000T(Scanning Hydrographic Operational Airborne Lidar Survey)system which consists of an airborne laser transmitter/receiver...

Preliminary study of airborne electromagnetic survey using grounded source; Chihyo source gata kuchu denji tansa no kisoteki kenkyu

Energy Technology Data Exchange (ETDEWEB)

Mogi, T [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Shimoizumi, M [Kitakyushu Polytechnic College, Kitakyushu (Japan); Kusunoki, K [Central Research Institute of Electric Power Industry, Tokyo (Japan); Morikawa, T [Dowa Engineering Co. Ltd., Okayama (Japan); Jomori, N [Chiba Electronics Research Institute, Chiba (Japan)

1996-05-01

For the development of an airborne electromagnetic prospecting method capable of deeper exploration, a basic study was made about a system wherein a transmitter (source) is positioned on the ground and the receiving is done in the sky. Even in case of this airborne electromagnetic method, the TDEM method is supposedly advantageous over others as in case of groundborne exploration. In the study, the transient response of an airborne vertical magnetic field to a horizontal layered structure was calculated. The current source was 2000m long with a capacity of 30A. The one-layer structure was a 10 Ohm m semi-infinite ground, and the two-layer structure had a 100 Ohm m structure just under the one-layer structure. The result of the calculation suggests that, in the absence of a layer of extremely low resistivity, observation of an approximately 1 second long transient response aboard a helicopter flying at approximately 50km/h will enable an approximately 1000m deep exploration. Problems to affect airborne observation, such as swinging, natural magnetic field fluctuation, and artificially produced noises were investigated by use of a magnetometer suspended from a helicopter in flight. 2 refs., 6 figs.

Chiral gravity, log gravity, and extremal CFT

International Nuclear Information System (INIS)

Maloney, Alexander; Song Wei; Strominger, Andrew

2010-01-01

We show that the linearization of all exact solutions of classical chiral gravity around the AdS 3 vacuum have positive energy. Nonchiral and negative-energy solutions of the linearized equations are infrared divergent at second order, and so are removed from the spectrum. In other words, chirality is confined and the equations of motion have linearization instabilities. We prove that the only stationary, axially symmetric solutions of chiral gravity are BTZ black holes, which have positive energy. It is further shown that classical log gravity--the theory with logarithmically relaxed boundary conditions--has finite asymptotic symmetry generators but is not chiral and hence may be dual at the quantum level to a logarithmic conformal field theories (CFT). Moreover we show that log gravity contains chiral gravity within it as a decoupled charge superselection sector. We formally evaluate the Euclidean sum over geometries of chiral gravity and show that it gives precisely the holomorphic extremal CFT partition function. The modular invariance and integrality of the expansion coefficients of this partition function are consistent with the existence of an exact quantum theory of chiral gravity. We argue that the problem of quantizing chiral gravity is the holographic dual of the problem of constructing an extremal CFT, while quantizing log gravity is dual to the problem of constructing a logarithmic extremal CFT.

Airborne gamma-ray spectrometer and magnetometer survey: Crescent Quadrangle, Burns Quadrangle, Canyon City Quadrangle, Bend Quadrangle, Salem Quadrangle (Oregon). Final report

International Nuclear Information System (INIS)

1981-01-01

An airborne combining radiometric and magnetic survey was performed for the Department of Energy over the area covered by the Burns, Crescent, Canyon City, Bend, and Salem, Washington 1:250,000 National Topographic Map Series, 1 0 x 2 0 quadrangle maps. The survey was a part of DOE's National Aerial Radiometric Reconnaissance program, which is in turn a part of the National Uranium Resource Evaluation program. Data were collected by a helicopter equipped with a gamma-ray spectrometer having a large crystal volume, and a high sensitivity proton precession magnetometer. The radiometric system was calibrated at the Walker Field Calibration pads and the Lake Mead Dynamic Test range. Data quality was ensured throughout the survey by daily test flights and equipment checks. Radiometric data were corrected for live time, aircraft and equipment background, cosmic background, atmospheric radon, Compton scatter, and altitude dependence. The corrected data were statistically evaluated, plotted, and contoured to produce anomaly maps based on the radiometric response of individual geological units. These maps were interpreted and an anomaly interpretation map produced. Volume I contains a description of the systems used in the survey, a discussion of the calibration of the systems, the data processing procedures, the data display format, the interpretation rationale, and the interpretation methodology. A separate Volume II for each quadrangle contains the data displays and the interpretation results

RESUME 95. Rapid environmental surveying using mobile equipment

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

The RESUME95 exercise - Rapid Environmental Surveying Using Mobile Equipment, took place in Finland in August 1995. The objectives of the RESUME exercise were to compare different monitoring systems when used under the same conditions as well as to compare results from similar systems with different data analysis and presentation software. Another objective was to acquire some basic knowledge to standardize and cross calibrate the European air-borne gamma-ray surveying capability so that the results from different systems could be directly comparable. The exercise involved 10 airborn monitoring teams, 7 teams with vehicle monitoring systems as well as ground survey teams from 8 countries. Most systems incorporated GPS satellite navigational aids and computers for real time display of the data which was also recorded for post flight analysis. Most of the car- and airborne systems were based on Nal detectors whereas most of the In-situ systems and a few airborne systems were based on HpGe detectors. The exercise took place in an area near Lahti. Three different areas were surveyed. These were 1) An airfield near Vesivehmaa, which was intended as a calibration site. Soil samples had been taken previously and used to establish the {sup 137}Cs activity of the soil as well as the activity of the natural radioactivity elements {sup 40}K, {sup 214}Bi and {sup 208}Tl. 2) An area contaminated by the Chernobyl nuclear accident, Area II. This area was intended to test the capabilities of the car- and airborne teams for mapping {sup 137}Cs. A number of predefined points in the area were used by In-situ teams. 3) An area with a variety of hidden readioactive sources, Area III. These sources of {sup 60}Co, {sup 137}Cs, {sup 192}Lr and {sup 99}Tc ranged in activity from 0.6 mCi to 15 Ci and was used to test the capability of the different air-borne teams for locating lost radioactive sources. (EG).

RESUME 95. Rapid environmental surveying using mobile equipment

International Nuclear Information System (INIS)

1997-01-01

The RESUME95 exercise - Rapid Environmental Surveying Using Mobile Equipment, took place in Finland in August 1995. The objectives of the RESUME exercise were to compare different monitoring systems when used under the same conditions as well as to compare results from similar systems with different data analysis and presentation software. Another objective was to acquire some basic knowledge to standardize and cross calibrate the European air-borne gamma-ray surveying capability so that the results from different systems could be directly comparable. The exercise involved 10 airborn monitoring teams, 7 teams with vehicle monitoring systems as well as ground survey teams from 8 countries. Most systems incorporated GPS satellite navigational aids and computers for real time display of the data which was also recorded for post flight analysis. Most of the car- and airborne systems were based on Nal detectors whereas most of the In-situ systems and a few airborne systems were based on HpGe detectors. The exercise took place in an area near Lahti. Three different areas were surveyed. These were 1) An airfield near Vesivehmaa, which was intended as a calibration site. Soil samples had been taken previously and used to establish the 137 Cs activity of the soil as well as the activity of the natural radioactivity elements 40 K, 214 Bi and 208 Tl. 2) An area contaminated by the Chernobyl nuclear accident, Area II. This area was intended to test the capabilities of the car- and airborne teams for mapping 137 Cs. A number of predefined points in the area were used by In-situ teams. 3) An area with a variety of hidden readioactive sources, Area III. These sources of 60 Co, 137 Cs, 192 Lr and 99 Tc ranged in activity from 0.6 mCi to 15 Ci and was used to test the capability of the different air-borne teams for locating lost radioactive sources. (EG)

RESUME 95. Rapid environmental surveying using mobile equipment

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-31

The RESUME95 exercise - Rapid Environmental Surveying Using Mobile Equipment, took place in Finland in August 1995. The objectives of the RESUME exercise were to compare different monitoring systems when used under the same conditions as well as to compare results from similar systems with different data analysis and presentation software. Another objective was to acquire some basic knowledge to standardize and cross calibrate the European air-borne gamma-ray surveying capability so that the results from different systems could be directly comparable. The exercise involved 10 airborn monitoring teams, 7 teams with vehicle monitoring systems as well as ground survey teams from 8 countries. Most systems incorporated GPS satellite navigational aids and computers for real time display of the data which was also recorded for post flight analysis. Most of the car- and airborne systems were based on Nal detectors whereas most of the In-situ systems and a few airborne systems were based on HpGe detectors. The exercise took place in an area near Lahti. Three different areas were surveyed. These were 1) An airfield near Vesivehmaa, which was intended as a calibration site. Soil samples had been taken previously and used to establish the {sup 137}Cs activity of the soil as well as the activity of the natural radioactivity elements {sup 40}K, {sup 214}Bi and {sup 208}Tl. 2) An area contaminated by the Chernobyl nuclear accident, Area II. This area was intended to test the capabilities of the car- and airborne teams for mapping {sup 137}Cs. A number of predefined points in the area were used by In-situ teams. 3) An area with a variety of hidden readioactive sources, Area III. These sources of {sup 60}Co, {sup 137}Cs, {sup 192}Lr and {sup 99}Tc ranged in activity from 0.6 mCi to 15 Ci and was used to test the capability of the different air-borne teams for locating lost radioactive sources. (EG).

Environmental radioactivity in the UK: the airborne geophysical view of dose rate estimates

International Nuclear Information System (INIS)

Beamish, David

2014-01-01

This study considers UK airborne gamma-ray data obtained through a series of high spatial resolution, low altitude surveys over the past decade. The ground concentrations of the naturally occurring radionuclides Potassium, Thorium and Uranium are converted to air absorbed dose rates and these are used to assess terrestrial exposure levels from both natural and technologically enhanced sources. The high resolution airborne information is also assessed alongside existing knowledge from soil sampling and ground-based measurements of exposure levels. The surveys have sampled an extensive number of the UK lithological bedrock formations and the statistical information provides examples of low dose rate lithologies (the formations that characterise much of southern England) to the highest sustained values associated with granitic terrains. The maximum dose rates (e.g. >300 nGy h −1 ) encountered across the sampled granitic terrains are found to vary by a factor of 2. Excluding granitic terrains, the most spatially extensive dose rates (>50 nGy h −1 ) are found in association with the Mercia Mudstone Group (Triassic argillaceous mudstones) of eastern England. Geological associations between high dose rate and high radon values are also noted. Recent studies of the datasets have revealed the extent of source rock (i.e. bedrock) flux attenuation by soil moisture in conjunction with the density and porosity of the temperate latitude soils found in the UK. The presence or absence of soil cover (and associated presence or absence of attenuation) appears to account for a range of localised variations in the exposure levels encountered. The hypothesis is supported by a study of an extensive combined data set of dose rates obtained from soil sampling and by airborne geophysical survey. With no attenuation factors applied, except those intrinsic to the airborne estimates, a bias to high values of between 10 and 15 nGy h −1 is observed in the soil data. A wide range of

DenInv3D: a geophysical software for three-dimensional density inversion of gravity field data

Science.gov (United States)

Tian, Yu; Ke, Xiaoping; Wang, Yong

2018-04-01

This paper presents a three-dimensional density inversion software called DenInv3D that operates on gravity and gravity gradient data. The software performs inversion modelling, kernel function calculation, and inversion calculations using the improved preconditioned conjugate gradient (PCG) algorithm. In the PCG algorithm, due to the uncertainty of empirical parameters, such as the Lagrange multiplier, we use the inflection point of the L-curve as the regularisation parameter. The software can construct unequally spaced grids and perform inversions using such grids, which enables changing the resolution of the inversion results at different depths. Through inversion of airborne gradiometry data on the Australian Kauring test site, we discovered that anomalous blocks of different sizes are present within the study area in addition to the central anomalies. The software of DenInv3D can be downloaded from http://159.226.162.30.

An analysis of the lithology to resistivity relationships using airborne EM and boreholes

DEFF Research Database (Denmark)

Barfod, Adrian A.S.; Christiansen, Anders Vest; Møller, Ingelise

2014-01-01

We present a study of the relationship between dense airborne skyTEM resistivity data and sparse lithological borehole data. Understanding the resistivity structure of the subsurface is of great importance to hydrogeological surveys and to ensure a high standard for groundwater quality. Borehole ...

MX Siting Investigation. Gravity Survey - Sevier Desert Valley, Utah.

Science.gov (United States)

1981-01-24

Cheyenne, Wyoming. DMAHTC reduces the data to Simple Bouguer Anomaly (see Section A1.4, Appendix Al.0). The Defense Mapping Agency Aerospace Center...Desert Valley, Utah ......... 2 2 Topographic Setting - Sevier Desert Valley, Utah . 3 LIST OF DRAWINGS Drawing Number 1 Complete Bouguer Anomaly...gravity stations were distributed throughout the valley at an approxi- mate interval of 1.4 miles (2.3 km). Drawing 1 is a Complete Bouguer Anomaly

Clear and Measurable Signature of Modified Gravity in the Galaxy Velocity Field

Science.gov (United States)

Hellwing, Wojciech A.; Barreira, Alexandre; Frenk, Carlos S.; Li, Baojiu; Cole, Shaun

2014-06-01

The velocity field of dark matter and galaxies reflects the continued action of gravity throughout cosmic history. We show that the low-order moments of the pairwise velocity distribution v12 are a powerful diagnostic of the laws of gravity on cosmological scales. In particular, the projected line-of-sight galaxy pairwise velocity dispersion σ12(r) is very sensitive to the presence of modified gravity. Using a set of high-resolution N-body simulations, we compute the pairwise velocity distribution and its projected line-of-sight dispersion for a class of modified gravity theories: the chameleon f(R) gravity and Galileon gravity (cubic and quartic). The velocities of dark matter halos with a wide range of masses would exhibit deviations from general relativity at the (5-10)σ level. We examine strategies for detecting these deviations in galaxy redshift and peculiar velocity surveys. If detected, this signature would be a "smoking gun" for modified gravity.

Airborne gamma-ray spectrometry data processing using 1.5D inversion.

Science.gov (United States)

Druker, Eugene

2017-10-01

Standard processing of Airborne Gamma-Ray Spectrometry data generally gives good results when the measurement conditions are almost constant within several footprint area sizes, with the possible exception of flight height variations in a small range. In practice, deviations, such as large or abrupt changes of flight height and/or rugged terrain are not so rare and lead to certain problems. This article proposes a different approach where the solutions of inverse problems are used for data processing. The approach is quite natural in the processing of field data measured along the flight lines: it explicitly takes into account 1.5D survey models and flight parameters - from topography to sources distribution on the surface. Also, it clearly demonstrates that the inverse problem of the Airborne Gamma-Ray Spectrometry does not have a unique solution. This feature can be used in accordance with the underlying geological problem since various formulations of inverse problems can lead to various geological solutions. The use of the approach is illustrated by several examples given for flight lines and survey areas. This approach can be particularly useful in situations where geological, geophysical and/or geographic survey conditions are far from the standard assumptions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterizing exposures to airborne metals and nanoparticle emissions in a refinery.

Science.gov (United States)

Miller, Arthur; Drake, Pamela L; Hintz, Patrick; Habjan, Matt

2010-07-01

An air quality survey was conducted at a precious metals refinery in order to evaluate worker exposures to airborne metals and to provide detailed characterization of the aerosols. Two areas within the refinery were characterized: a furnace room and an electro-refining area. In line with standard survey practices, both personal and area air filter samples were collected on 37-mm filters and analyzed for metals by inductively coupled plasma-atomic emission spectroscopy. In addition to the standard sampling, measurements were conducted using other tools, designed to provide enhanced characterization of the workplace aerosols. The number concentration and number-weighted particle size distribution of airborne particles were measured with a fast mobility particle sizer (FMPS). Custom-designed software was used to correlate particle concentration data with spatial location data to generate contour maps of particle number concentrations in the work areas. Short-term samples were collected in areas of localized high concentrations and analyzed using transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) to determine particle morphology and elemental chemistry. Analysis of filter samples indicated that all of the workers were exposed to levels of silver above the Occupational Safety and Health Administration permissible exposure limit of 0.01 mg m(-3) even though the localized ventilation was functioning. Measurements with the FMPS indicated that particle number concentrations near the furnace increased up to 1000-fold above the baseline during the pouring of molten metal. Spatial mapping revealed localized elevated particle concentrations near the furnaces and plumes of particles rising into the stairwells and traveling to the upper work areas. Results of TEM/EDS analyses confirmed the high number of nanoparticles measured by the FMPS and indicated the aerosols were rich in metals including silver, lead, antimony, selenium, and zinc. Results of

Petroleum system of Northwest Java basin based on gravity data analysis

Science.gov (United States)

Widianto, E.

2018-01-01

Energy management in the upstream oil and gas sector becomes very important for the country’s energy security. The renewal of energy resources and reserves becomes necessary and is a must. In the oil and gas industry, gravity data is usually used only for regional surveys, but with the development of instrumentation technology and gravity software development, this method can be used for assessing oil and gas survey stages from exploration to production. This study was conducted to evaluate aspects of petroleum system and exploration play concept in the part of Northwest Java Basin, covering source rock deposition regions (source kitchen area, migration direction), development of reservoirs, structural and stratigraphic trap, based on gravity data. This study uses data from Bouguer gravity anomaly map by filtering process to produce a residual map depicting sedimentation basin configuration. The mapping generated 20 sedimentary basins in Java Island with the total hydrocarbon resources of 113 BBOE (Billion Barrel of Oil Equivalent). The petroleum system analysis was conducted in the Northwest Basin section. The final map produced illustrates the condition of petroleum system and play concept that can be used as exploration direction, expectedly reducing the risk of drilling failure.

ASTEROSEISMIC-BASED ESTIMATION OF THE SURFACE GRAVITY FOR THE LAMOST GIANT STARS

International Nuclear Information System (INIS)

Liu, Chao; Wu, Yue; Deng, Li-Cai; Wang, Liang; Wang, Wei; Li, Guang-Wei; Fang, Min; Fu, Jian-Ning; Hou, Yong-Hui; Zhang, Yong

2015-01-01

Asteroseismology is one of the most accurate approaches to estimate the surface gravity of a star. However, most of the data from the current spectroscopic surveys do not have asteroseismic measurements, which is very expensive and time consuming. In order to improve the spectroscopic surface gravity estimates for a large amount of survey data with the help of the small subset of the data with seismic measurements, we set up a support vector regression (SVR) model for the estimation of the surface gravity supervised by 1374 Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) giant stars with Kepler seismic surface gravity. The new approach can reduce the uncertainty of the estimates down to about 0.1 dex, which is better than the LAMOST pipeline by at least a factor of 2, for the spectra with signal-to-noise ratio higher than 20. Compared with the log g estimated from the LAMOST pipeline, the revised log g values provide a significantly improved match to the expected distribution of red clump and red giant branch stars from stellar isochrones. Moreover, even the red bump stars, which extend to only about 0.1 dex in log g, can be discriminated from the new estimated surface gravity. The method is then applied to about 350,000 LAMOST metal-rich giant stars to provide improved surface gravity estimates. In general, the uncertainty of the distance estimate based on the SVR surface gravity can be reduced to about 12% for the LAMOST data

ASTEROSEISMIC-BASED ESTIMATION OF THE SURFACE GRAVITY FOR THE LAMOST GIANT STARS

Energy Technology Data Exchange (ETDEWEB)

Liu, Chao; Wu, Yue; Deng, Li-Cai; Wang, Liang; Wang, Wei; Li, Guang-Wei [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20 A Datun Road, Beijing 100012 (China); Fang, Min [Departamento de Física Teórica, Facultad de Ciencias, Universidad Autonóma de Madrid, E-28049 Cantoblanco, Madrid (Spain); Fu, Jian-Ning [Department of Astronomy, Beijing Normal University, 19 Avenue Xinjiekouwai, Beijing 100875 (China); Hou, Yong-Hui; Zhang, Yong, E-mail: liuchao@nao.cas.cn [Nanjing Institute of Astronomical Optics and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Nanjing 210042 (China)

2015-07-01

Asteroseismology is one of the most accurate approaches to estimate the surface gravity of a star. However, most of the data from the current spectroscopic surveys do not have asteroseismic measurements, which is very expensive and time consuming. In order to improve the spectroscopic surface gravity estimates for a large amount of survey data with the help of the small subset of the data with seismic measurements, we set up a support vector regression (SVR) model for the estimation of the surface gravity supervised by 1374 Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) giant stars with Kepler seismic surface gravity. The new approach can reduce the uncertainty of the estimates down to about 0.1 dex, which is better than the LAMOST pipeline by at least a factor of 2, for the spectra with signal-to-noise ratio higher than 20. Compared with the log g estimated from the LAMOST pipeline, the revised log g values provide a significantly improved match to the expected distribution of red clump and red giant branch stars from stellar isochrones. Moreover, even the red bump stars, which extend to only about 0.1 dex in log g, can be discriminated from the new estimated surface gravity. The method is then applied to about 350,000 LAMOST metal-rich giant stars to provide improved surface gravity estimates. In general, the uncertainty of the distance estimate based on the SVR surface gravity can be reduced to about 12% for the LAMOST data.

Airborne radionuclide waste-management reference document

International Nuclear Information System (INIS)

Brown, R.A.; Christian, J.D.; Thomas, T.R.

1983-07-01

This report provides the detailed data required to develop a strategy for airborne radioactive waste management by the Department of Energy (DOE). The airborne radioactive materials of primary concern are tritium (H-3), carbon-14 (C-14), krypton-85 (Kr-85), iodine-129 (I-129), and radioactive particulate matter. The introductory section of the report describes the nature and broad objectives of airborne waste management. The relationship of airborne waste management to other waste management programs is described. The scope of the strategy is defined by considering all potential sources of airborne radionuclides and technologies available for their management. Responsibilities of the regulatory agencies are discussed. Section 2 of this document deals primarily with projected inventories, potential releases, and dose commitments of the principal airborne wastes from the light water reactor (LWR) fuel cycle. In Section 3, dose commitments, technologies, costs, regulations, and waste management criteria are analyzed. Section 4 defines goals and objectives for airborne waste management

Neah Bay to Cape Alava, Northwest Coast, Washington State - Topographic Survey Data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data were collected by the SHOALS-1000T(Scanning Hydrographic Operational Airborne Lidar Survey)system which consists of an airborne laser transmitter/receiver...

Airborne electromagnetic data and processing within Leach Lake Basin, Fort Irwin, California: Chapter G in Geology and geophysics applied to groundwater hydrology at Fort Irwin, California

Science.gov (United States)

Bedrosian, Paul A.; Ball, Lyndsay B.; Bloss, Benjamin R.; Buesch, David C.

2014-01-01

From December 2010 to January 2011, the U.S. Geological Survey conducted airborne electromagnetic and magnetic surveys of Leach Lake Basin within the National Training Center, Fort Irwin, California. These data were collected to characterize the subsurface and provide information needed to understand and manage groundwater resources within Fort Irwin. A resistivity stratigraphy was developed using ground-based time-domain electromagnetic soundings together with laboratory resistivity measurements on hand samples and borehole geophysical logs from nearby basins. This report releases data associated with the airborne surveys, as well as resistivity cross-sections and depth slices derived from inversion of the airborne electromagnetic data. The resulting resistivity models confirm and add to the geologic framework, constrain the hydrostratigraphy and the depth to basement, and reveal the distribution of faults and folds within the basin.

Airborne relay-based regional positioning system.

Science.gov (United States)

Lee, Kyuman; Noh, Hongjun; Lim, Jaesung

2015-05-28

Ground-based pseudolite systems have some limitations, such as low vertical accuracy, multipath effects and near-far problems. These problems are not significant in airborne-based pseudolite systems. However, the monitoring of pseudolite positions is required because of the mobility of the platforms on which the pseudolites are mounted, and this causes performance degradation. To address these pseudolite system limitations, we propose an airborne relay-based regional positioning system that consists of a master station, reference stations, airborne relays and a user. In the proposed system, navigation signals are generated from the reference stations located on the ground and are relayed via the airborne relays. Unlike in conventional airborne-based systems, the user in the proposed system sequentially estimates both the locations of airborne relays and his/her own position. Therefore, a delay due to monitoring does not occur, and the accuracy is not affected by the movement of airborne relays. We conducted several simulations to evaluate the performance of the proposed system. Based on the simulation results, we demonstrated that the proposed system guarantees a higher accuracy than airborne-based pseudolite systems, and it is feasible despite the existence of clock offsets among reference stations.

Mass Tracking with a MEMS-based Gravity Sensor

Science.gov (United States)

Pike, W. T.; Mukherjee, A.; Warren, T.; Charalambous, C.; Calcutt, S. B.; Standley, I.

2017-12-01

We achieve the first demonstration of the dynamic location of a moving mass using a MEMS sensor to detect gravity. The sensor is based on a microseismometer developed for planetary geophysics. In an updated version of the original Cavendish experiment the noise floor of the sensor, at 0.25 µgal/rtHz, allows the determination of the dynamic gravitational field from the motion of the mass of an oscillating pendulum. Using the determined noise floor we show that this performance should be sufficient for practical subsurface gravity surveying, in particular detection of 50-cm diameter pipes up to 10 m below the surface. Beyond this specific application, this sensor with a mass of less than 250 g per axis represents a new technology that opens up the possibility of drone deloyments for gravity mapping.

Large Airborne Full Tensor Gradient Data Inversion Based on a Non-Monotone Gradient Method

Science.gov (United States)

Sun, Yong; Meng, Zhaohai; Li, Fengting

2018-03-01

Following the development of gravity gradiometer instrument technology, the full tensor gravity (FTG) data can be acquired on airborne and marine platforms. Large-scale geophysical data can be obtained using these methods, making such data sets a number of the "big data" category. Therefore, a fast and effective inversion method is developed to solve the large-scale FTG data inversion problem. Many algorithms are available to accelerate the FTG data inversion, such as conjugate gradient method. However, the conventional conjugate gradient method takes a long time to complete data processing. Thus, a fast and effective iterative algorithm is necessary to improve the utilization of FTG data. Generally, inversion processing is formulated by incorporating regularizing constraints, followed by the introduction of a non-monotone gradient-descent method to accelerate the convergence rate of FTG data inversion. Compared with the conventional gradient method, the steepest descent gradient algorithm, and the conjugate gradient algorithm, there are clear advantages of the non-monotone iterative gradient-descent algorithm. Simulated and field FTG data were applied to show the application value of this new fast inversion method.

Optical Airborne Tracker System

Data.gov (United States)

National Aeronautics and Space Administration — The Optical Airborne Tracker System (OATS) is an airborne dual-axis optical tracking system capable of pointing at any sky location or ground target.  The objectives...

Applicability of the grounded-source airborne electromagnetics to coastal areas

International Nuclear Information System (INIS)

Ito, Hisatoshi; Tsukuda, Kazuhiro; Suzuki, Koichi; Kaieda, Hideshi; Kiho, Kenzo; Mogi, Toru

2012-01-01

Understanding geological and hydrogeological characteristics in coastal areas is an issue of paramount importance especially with regard to siting of geological disposal of nuclear wastes, whereas conventional airborne electromagnetic (AEM) surveys can reveal an electrical resistivity structure to a depth of only ∼200 m. In order to enhance the depth of investigation, we have developed a new type of AEM, grounded-electrical-source airborne transient electromagnetics (GREATEM). Here we have applied GREATEM to two coastal areas in Japan; Kujukuri, an alluvial coastal plain where thick Quaternary sediments prevail, and northwestern part of Awaji Island, where granitic rocks are dominant. It was found that the GREATEM system can reveal resistivity structure to a depth of ∼500 m and also high quality data are available just beneath the shoreline where shallow water prevails. (author)

A feasibility study of geogenic indoor radon mapping from airborne radiometric survey in northern Thailand

Energy Technology Data Exchange (ETDEWEB)

Wattananikorn, K. [Department of Physics, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)], E-mail: kittic@science.cmu.ac.th; Emharuthai, S. [Department of Physics, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wanaphongse, P. [Office of Atoms for Peace, Bangkok (Thailand)

2008-01-15

Experiments were carried out in seven test sites on three Quaternary alluvial and terrace deposit basins of northern Thailand, to test the possibility of using airborne equivalent uranium to predict geogenic indoor radon values of the region. The methodology was based on the correlation among soil gas permeability, soil radon concentration and indoor radon, as well as a relationship between soil radon and airborne uranium values. The methodology established works rather well when tested in areas of known indoor radon. Based on the predicted values that were obtained from this method, indoor radon in most areas of alluvial and terrace deposit basins of northern Thailand is less than 44Bq/m{sup 3}. There is no area in these basins where predicted indoor radon exceeds 74Bq/m{sup 3}.

Survey result of airborne electromagnetic survey in the Hachimantai Sumikawa landslide area; Hachimantai Sumikawa jisuberi ni okeru kuchu denjiho chosa kekka

Energy Technology Data Exchange (ETDEWEB)

Konishi, N; Nakamura, N; Miyamoto, T [Nippon Engineering Consultant Co. Ltd., Tokyo (Japan)

1997-10-22

For the study of a landslide that occurred at Hachimantai Sumikawa, Akita Prefecture, an airborne electromagnetic survey is conducted for the examination of the relationship between the spot of landslide and solfataric clay (bluish gray clay). The location is a cap block type structure with a Neogene green tuff overlain by accumulated lava flow, where hot water is very active. The system used in this study is capable of measurement across a very wide frequency range, and measurements are made simultaneously at five frequencies of 220Hz, 1100Hz, 5500Hz, 27,500Hz, and 137,500Hz, these frequencies meaning depth levels 5m-70m explored. It is found that the spot of landslide matches a region where resistivity is so low as to be not higher than 10ohm/m. It is also found, in the resistivity cross section analysis for the middle part of the spot of landslide, that the mass of soil that moved on the upper part of the spot is relatively high in resistivity while the part below the slide surface is low in resistivity. There is agreement between the results reported above and the results of on-site investigations. 4 refs., 6 figs.

Diurnal Variations of Airborne Pollen and Spores in Taipei City, Taiwan

Directory of Open Access Journals (Sweden)

Yueh-Lin Yang

2003-09-01

Full Text Available The diurnal variation of airborne pollen and spores in Taipei City, Taiwan, was investigated during a two-year survey from 1993 to 1994. The pollen and spores were sampled using a Burkard seven-day volumetric pollen trap. The diurnal trends of the total amount of pollen and spores in 1993 and in 1994 were similar to each other, and peaked at 3 to 10 o’clock. The diurnal patterns of airborne pollen and spores of Broussonetia, Fraxinus, Cyathea and Gramineae in 1993 were similar to those in 1994. High concentrations of Broussonetia and Fraxinus were obtained from midnight to the next morning. Cyathea spores peaked from morning till noon, and Gramineae peaked in the afternoon. The diurnal patterns of airborne pollen of Bischofia, Juniperus, Mallotus, Morus, Trema and Urticaceae in 1993 were different to those in 1994. Regular diurnal patterns also associated with the taxa, which produce large pollen or spores, such as Gramineae and Cyathea. In contrast, Bischofia, Juniperus, Mallotus, Morus, Trema and Urticaceae produce relatively small pollen and the diurnal patterns of their airborne pollen were found irregular. The source plants Broussonetia and Fraxinus were close to the collection site so the diurnal patterns of their airborne pollen were regular, suggesting that the diurnal fluctuations of the pollen or spores in air might be affected by the source of plants and the sizes of pollen or spores. The transportation of the smaller pollen or spores in air is probably more easily affected by instability of air currents; they are therefore more likely to exhibit irregular diurnal patterns.

Interaction between two adjacent grounded sources in frequency domain semi-airborne electromagnetic survey.

Science.gov (United States)

Zhou, Haigen; Lin, Jun; Liu, Changsheng; Kang, Lili; Li, Gang; Zeng, Xinsen

2016-03-01

Multi-source and multi-frequency emission method can make full use of the valuable and short flight time in frequency domain semi-airborne electromagnetic (FSAEM) exploration, which has potential to investigate the deep earth structure in complex terrain region. Because several sources are adjacent in multi-source emission method, the interaction of different sources should be considered carefully. An equivalent circuit model of dual-source is established in this paper to assess the interaction between two individual sources, where the parameters are given with the typical values based on the practical instrument system and its application. By simulating the output current of two sources in different cases, the influence from the adjacent source is observed clearly. The current waveforms show that the mutual resistance causes the fluctuation and drift in another source and that the mutual inductance causes transient peaks. A field test with dual-source was conducted to certify the existence of interaction between adjacent sources. The simulation of output current also shows that current errors at low frequency are mainly caused by the mutual resistance while those at high frequency are mainly due to the mutual inductance. Increasing the distance between neighboring sources is a proposed measure to reduce the emission signal errors with designed ones. The feasible distance is discussed in the end. This study gives a useful guidance to lay multi sources to meet the requirement of measurement accuracy in FSAEM survey.

A Study on Factors Affecting Airborne LiDAR Penetration

Directory of Open Access Journals (Sweden)

Wei-Chen Hsu

2015-01-01

Full Text Available This study uses data from different periods, areas and parameters of airborne LiDAR (light detection and ranging surveys to understand the factors that influence airborne LiDAR penetration rate. A discussion is presented on the relationships between these factors and LiDAR penetration rate. The results show that the flight height above ground level (AGL does not have any relationship with the penetration rate. There are some factors that should have larger influence. For example, the laser is affected by a wet ground surface by reducing the number of return echoes. The field of view (FOV has a slightly negative correlation with the penetration rate, which indicates that the laser incidence angle close to zero should achieve the best penetration. The vegetation cover rate also shows a negative correlation with the penetration rate, thus bare ground and reduced vegetation in the aftermath of a typhoon also cause high penetration rate. More return echoes could be extracted from the full-waveform system, thereby effectively improving the penetration rate. This study shows that full-waveform LiDAR is an effective method for increasing the number of surface reflected echoes. This study suggests avoiding LiDAR survey employment directly following precipitation to prevent laser echo reduction.

Lithologic boundaries from gravity and magnetic anomalies over Proterozoic Dalma volcanics

Science.gov (United States)

Yadav, Pramod Kumar; Adhikari, P. K.; Srivastava, Shalivahan; Maurya, Ved P.; Tripathi, Anurag; Singh, Shailendra; Singh, Roshan K.; Bage, Ashish K.

2018-03-01

Dalma volcanics (DVs) has intruded the older Singhbhum Group of Metapelites. Despite DVs being rich in mineralisation, its boundaries are not clearly demarcated. Gravity and magnetic surveys have been attempted for mapping the boundaries in DVs. These surveys were made in the northern fringe of the DVs over an area of ˜ 0.70 km2 along 13 parallel lines at 50 m spacing. The data was acquired at ˜ 25 m spacing. The surveys were taken for determination of lithological boundaries, depths and nature of causative source using Euler depth solutions and radially averaged power spectrum (RAPS). Residual anomaly maps of gravity and magnetic intensity show the same trend as that of Bouguer gravity anomaly and total magnetic intensity anomaly map indicating towards shallow sources. The magnetic map in general follows the same pattern as that of gravity anomaly maps. The map shows coincident high gravity and magnetic anomalies. These anomalies together with resistivity signatures confirm that the northern fringe of DVs hosts volcanogenic massive sulphide settings. The Euler depth solution delineated the lateral boundaries and nature of the source. It seems that the source is of spherical nature lying within a depth range of 25-40 m. The obtained lithological (vertical) units from RAPS are between Lower DVs, Upper DVs and Singhbhum Group Metapelites at depths of ˜ 15, ˜ 25 and ˜ 40 m, respectively. The metallogeny is associated with the Upper DVs and the corresponding delineated lithological (vertical) unit is indicative of the top of the ore body. Good agreement is observed with the geological succession from the drilling data and resistivity data. The findings suggest that the northern fringe of DVs could be a preferred target for drilling.

Even-dimensional topological gravity from Chern-Simons gravity

International Nuclear Information System (INIS)

Merino, N.; Perez, A.; Salgado, P.

2009-01-01

It is shown that the topological action for gravity in 2n-dimensions can be obtained from the (2n+1)-dimensional Chern-Simons gravity genuinely invariant under the Poincare group. The 2n-dimensional topological gravity is described by the dynamics of the boundary of a (2n+1)-dimensional Chern-Simons gravity theory with suitable boundary conditions. The field φ a , which is necessary to construct this type of topological gravity in even dimensions, is identified with the coset field associated with the non-linear realizations of the Poincare group ISO(d-1,1).

Design of Gravity Survey Network using Fractal Theory to Delineate Hydrocarbon bearing Jabera Structure, Vindhyan Basin, Central India

Science.gov (United States)

Dimri, V. P.; Srivastava, R. P.; Vedanti, N.

2006-12-01

A gravity survey network was designed using fractal dimension analysis to delineate a domal structure (Jabera dome) reported in southeastern part of the Vindhyan basin, Central India. This area is also regarded as a `high risk-high reward' frontier area for hydrocarbon exploration in previous studies, hence our aim was to delineate shape and lateral extent of the reported domal structure. Based on the synthetic grid, designed using the concept of fractal dimension, gravity data is collected in Jabera-Damoh area of Vindhyan basin. The collected data is random, but the data density is significant, hence the data points are sorted in a way so that they are close to the synthetic grid points of given grid interval. After sorting the data, again the fractal dimension analysis using box counting method has been carried out to avoid the aliasing in the data due to interpolation and also to know the optimum number of data points sufficient for desired quality of Bouguer anomaly maps. Optimization of number of stations takes care of time and cost involved in the survey and the detectibility limit ensures that the data collected is good enough to resolve the target body under study. The fractal dimension analysis gives clue to select these parameters. It showed that it is always preferable to have well distributed station locations instead of clustering the observation points at some geologically known feature because clustering of data points below required station spacing is not going to add much information where as equally distributed observation points add the information. The study area lies in a difficult terrain of Vindhayn basin, hence according to the accessibility, fractal dimension analysis of the real data sorted approximately at regular grid intervals on 2,3, and 4 km has been done and using the concept of optimum gridding interval Bouguer anomaly maps of the region are prepared. The preliminary depth values of the major interfaces in the area were obtained

Airborne Tactical Crossload Planner

Science.gov (United States)

2017-12-01

Regiment AGL above ground level AO area of operation APA American psychological association ASOP airborne standard operating procedure A/C aircraft...awarded a research contract to develop a tactical crossload tool. [C]omputer assisted Airborne Planning Application ( APA ) that provides a

Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: a case study of Irish Sea beaches.

Science.gov (United States)

Cresswell, A J; Sanderson, D C W

2012-10-15

In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq (137)Cs within large areas (10-20 km(2)h(-1)), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15m whilst maintaining speeds covering 1-2 km(2) h(-1) can detect buried (137)Cs sources of 0.5MBq or greater activity. A survey design to detect 100 kBq (137)Cs sources at 10 cm depth has also been defined, requiring surveys at <15m ground clearance and <2 ms(-1) ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

New geoid of Greenland: A case study of terrain and ice effects, GOCE and use of local sea level data

DEFF Research Database (Denmark)

Forsberg, René; Jensen, Tim Enzlberger

2015-01-01

Making an accurate geoid model of Greenland has always been a challenge due to the ice sheet and glaciers, and the rough topography and deep fjords in the ice free parts. Terrestrial gravity coverage has for the same reasons been relatively sparse, with an older airborne survey of the interior be...

Development and study of airborne spectrometer system being compatible with nuclear emergency monitoring

International Nuclear Information System (INIS)

Jiangqi, Fang; Huaiwu, Wang; Mingkao, Hu; Renkang, Gu

2002-01-01

The exploitation and use of nuclear energy are of great importance to developing of national economy and maintaining state security. But it also has a possibility of serious accident. Based on the principles of airborne gamma ray spectrometry in the uranium exploration, nuclear emergency monitoring has been developed. This method has high sensitivity to the radioactive nuclides in the air and on the ground, and with the advantage of fast measuring in large area. Hence, in the middle of 1980s, some developed countries began to survey the scope and degree of nuclear accident contamination and environmental radiation level monitoring in the surrounding nuclear facilities, it can also be used to search for the lost radioactive sources. According to the actual situation and compatible guideline, National Nuclear Emergency Office consigned this project to our Center. After development and study on the Airborne gamma ray spectrometer system associated NaI(Tl) used for the uranium exploration, a compatible spectrometer system associated NaI(Tl) was established in a short period by us, which can fulfill airborne nuclear emergency survey basically. In normal situation, it was proved that the start-up time is less than two hours including transport to the airport. The system has high sensitivity to radioactive plume of 41 Ar and can respond rapidly to artificial sources, such as 192 Ir, 60 Co, 137 Cs and 131 I etc

On regulation of radioactive airborne discharge

International Nuclear Information System (INIS)

Stroganov, A.A.; Kuryndin, A.V.; Shapovalov, A.S.; Orlov, M.Yu.

2013-01-01

Authors present the Russian regulatory basis of radioactive airborne discharges which was updated after enactment of the Methodology for airborne discharge limits development. Criteria for establishing of airborne discharge limits, scope and other features of methodology are also considered in the article [ru

HIGH RESOLUTION AIRBORNE SHALLOW WATER MAPPING

Directory of Open Access Journals (Sweden)

F. Steinbacher

2012-07-01

Full Text Available In order to meet the requirements of the European Water Framework Directive (EU-WFD, authorities face the problem of repeatedly performing area-wide surveying of all kinds of inland waters. Especially for mid-sized or small rivers this is a considerable challenge imposing insurmountable logistical efforts and costs. It is therefore investigated if large-scale surveying of a river system on an operational basis is feasible by employing airborne hydrographic laser scanning. In cooperation with the Bavarian Water Authority (WWA Weilheim a pilot project was initiated by the Unit of Hydraulic Engineering at the University of Innsbruck and RIEGL Laser Measurement Systems exploiting the possibilities of a new LIDAR measurement system with high spatial resolution and high measurement rate to capture about 70 km of riverbed and foreland for the river Loisach in Bavaria/Germany and the estuary and parts of the shoreline (about 40km in length of lake Ammersee. The entire area surveyed was referenced to classic terrestrial cross-section surveys with the aim to derive products for the monitoring and managing needs of the inland water bodies forced by the EU-WFD. The survey was performed in July 2011 by helicopter and airplane and took 3 days in total. In addition, high resolution areal images were taken to provide an optical reference, offering a wide range of possibilities on further research, monitoring, and managing responsibilities. The operating altitude was about 500 m to maintain eye-safety, even for the aided eye, the airspeed was about 55 kts for the helicopter and 75 kts for the aircraft. The helicopter was used in the alpine regions while the fixed wing aircraft was used in the plains and the urban area, using appropriate scan rates to receive evenly distributed point clouds. The resulting point density ranged from 10 to 25 points per square meter. By carefully selecting days with optimum water quality, satisfactory penetration down to the river

High Resolution Airborne Shallow Water Mapping

Science.gov (United States)

Steinbacher, F.; Pfennigbauer, M.; Aufleger, M.; Ullrich, A.

2012-07-01

In order to meet the requirements of the European Water Framework Directive (EU-WFD), authorities face the problem of repeatedly performing area-wide surveying of all kinds of inland waters. Especially for mid-sized or small rivers this is a considerable challenge imposing insurmountable logistical efforts and costs. It is therefore investigated if large-scale surveying of a river system on an operational basis is feasible by employing airborne hydrographic laser scanning. In cooperation with the Bavarian Water Authority (WWA Weilheim) a pilot project was initiated by the Unit of Hydraulic Engineering at the University of Innsbruck and RIEGL Laser Measurement Systems exploiting the possibilities of a new LIDAR measurement system with high spatial resolution and high measurement rate to capture about 70 km of riverbed and foreland for the river Loisach in Bavaria/Germany and the estuary and parts of the shoreline (about 40km in length) of lake Ammersee. The entire area surveyed was referenced to classic terrestrial cross-section surveys with the aim to derive products for the monitoring and managing needs of the inland water bodies forced by the EU-WFD. The survey was performed in July 2011 by helicopter and airplane and took 3 days in total. In addition, high resolution areal images were taken to provide an optical reference, offering a wide range of possibilities on further research, monitoring, and managing responsibilities. The operating altitude was about 500 m to maintain eye-safety, even for the aided eye, the airspeed was about 55 kts for the helicopter and 75 kts for the aircraft. The helicopter was used in the alpine regions while the fixed wing aircraft was used in the plains and the urban area, using appropriate scan rates to receive evenly distributed point clouds. The resulting point density ranged from 10 to 25 points per square meter. By carefully selecting days with optimum water quality, satisfactory penetration down to the river bed was achieved

Estimating Antarctica land topography from GRACE gravity and ICESat altimetry data

Science.gov (United States)

Wu, I.; Chao, B. F.; Chen, Y.

2009-12-01

We propose a new method combining GRACE (Gravity Recovery and Climate Experiment) gravity and ICESat (Ice, Cloud, and land Elevation Satellite) altimetry data to estimate the land topography for Antarctica. Antarctica is the fifth-largest continent in the world and about 98% of Antarctica is covered by ice, where in-situ measurements are difficult. Some experimental airborne radar and ground-based radar data have revealed very limited land topography beneath heavy ice sheet. To estimate the land topography for the full coverage of Antarctica, we combine GRACE data that indicate the mass distribution, with data of ICESat laser altimetry that provide high-resolution mapping of ice topography. Our approach is actually based on some geological constraints: assuming uniform densities of the land and ice considering the Airy-type isostasy. In the beginning we construct an initial model for the ice thickness and land topography based on the BEDMAP ice thickness and ICESat data. Thereafter we forward compute the model’s gravity field and compare with the GRACE observed data. Our initial model undergoes the adjustments to improve the fit between modeled results and the observed data. Final examination is done by comparing our results with previous but sparse observations of ice thickness to reconfirm the reliability of our results. As the gravitational inversion problem is non-unique, our estimating result is just one of all possibilities constrained by available data in optimal way.

Delineating the Rattlesnake Springs, New Mexico Watershed Using Precision Gravity Techniques

Science.gov (United States)

Doser, D. I.; Boykov, N. D.; Baker, M. R.; Kaip, G. M.; Langford, R. P.

2009-12-01

Rattlesnake Springs serves as the sole domestic water source for Carlsbad Caverns National Park. The recent development of oil and gas leases and agricultural lands surrounding the springs has led to concern about contamination of the fracture controlled aquifer system. We have conducted a series of precision gravity surveys (station spacing 200 to 300 m in a 4 x 4 km area), combined with other geophysical studies and geologic mapping, to delineate possible fracture systems in the gypsum and carbonate bedrock that feed the spring system. Our combined results suggest several pathways for water to enter the springs. A series of WNW-ESE striking features are apparent in our gravity data that appear to align with relict spring valleys we have mapped to the west of the springs. A self potential survey indicates that water is entering the springs at a shallow level from the northwest direction. However, gravity data also indicate a north-south trending fracture system could be providing a pathway for water to enter from the south. This is consistent with drawdown tests conducted in the 1950’s and 1960’s on irrigation wells located to the south of the springs. The north-south fracture system appears related to a basin bounding fault system observed in the regional gravity data.

Mapping methane emissions using the airborne imaging spectrometer AVIRIS-NG

Science.gov (United States)

Thorpe, A. K.; Frankenberg, C.; Thompson, D. R.; Duren, R. M.; Bue, B. D.; Green, R. O.

2017-12-01

The next generation Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-NG) has been used to survey large regions and map methane plumes with unambiguous identification of emission source locations. This capability is aided by real time detection and geolocation of gas plumes, permitting adaptive surveys and communication to ground teams for rapid follow up. We present results from AVIRIS-NG flight campaigns in Colorado, New Mexico, and California. Hundreds of plumes were observed, reflecting emissions from the energy sector that include hydraulic fracturing, gas processing plants, tanks, pumpjacks, and pipeline leaks. In some cases, plumes observed by AVIRIS-NG resulted in mitigation. Additional examples will be shown for methane from dairy lagoons, landfills, natural emissions, as well as carbon dioxide from power plants and refineries. We describe the unique capabilities of airborne imaging spectrometers to augment other measurement techniques by efficiently surveying key regions for methane point sources and supporting timely assessment and mitigation. We summarize the outlook for near- and longer-term monitoring capabilities including future satellite systems. Figure caption. AVIRIS-NG true color image subset with superimposed methane plume showing retrieved gas concentrations. Plume extends 200 m downwind of the southern edge of the well pad. Google Earth imagery with finer spatial resolution is also included (red box), indicating that tanks in the inset scene as the source of emissions. Five wells are located at the center of this well pad and all use horizontal drilling to produce mostly natural gas.

Lithologic boundaries from gravity and magnetic anomalies over ...

Indian Academy of Sciences (India)

67

The data was acquired at ~25 m spacing. The surveys were taken for determination of lithological boundaries, depths and nature of causative source using Euler depth solutions and radially averaged power spectrum (RAPS). Residual anomaly maps of gravity and magnetic. Manuscript. Click here to view linked References.

Routing architecture and security for airborne networks

Science.gov (United States)

Deng, Hongmei; Xie, Peng; Li, Jason; Xu, Roger; Levy, Renato

2009-05-01

Airborne networks are envisioned to provide interconnectivity for terrestial and space networks by interconnecting highly mobile airborne platforms. A number of military applications are expected to be used by the operator, and all these applications require proper routing security support to establish correct route between communicating platforms in a timely manner. As airborne networks somewhat different from traditional wired and wireless networks (e.g., Internet, LAN, WLAN, MANET, etc), security aspects valid in these networks are not fully applicable to airborne networks. Designing an efficient security scheme to protect airborne networks is confronted with new requirements. In this paper, we first identify a candidate routing architecture, which works as an underlying structure for our proposed security scheme. And then we investigate the vulnerabilities and attack models against routing protocols in airborne networks. Based on these studies, we propose an integrated security solution to address routing security issues in airborne networks.

Determining the 3D Subsurface Density Structure of Taurus Littrow Valley Using Apollo 17 Gravity Data

Science.gov (United States)

Urbancic, N.; Ghent, R.; Stanley, S,; Johnson, C. L.; Carroll, K. A.; Hatch, D.; Williamson, M. C.; Garry, W. B.; Talwani, M.

2016-01-01

Surface gravity surveys can detect subsurface density variations that can reveal subsurface geologic features. In 1972, the Apollo 17 (A17) mission conducted the Traverse Gravimeter Experiment (TGE) using a gravimeter that measured the local gravity field near Taurus Littrow Valley (TLV), located on the south-eastern rim of the Serenitatis basin. TLV is hypothesized to be a basaltfilled radial graben resulting from the impact that formed Mare Serenitatis. It is bounded by both the North and South Massifs (NM and SM) as well as other smaller mountains to the East that are thought to be mainly composed of brecciated highland material. The TGE is the first and only successful gravity survey on the surface of the Moon. Other more recent satellite surveys, such as NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission (2011- 2012), have produced the best global gravity field to date (approx. 13km resolution). However, these satellite surveys are not sensitive enough to detect fine-scale (<1km) lunar subsurface structures. This underscores the value of the data collected at the surface by A17. In the original analysis of the data a 2D forward-modelling approach was used to derive a thickness of the subsurface basalt layer of 1.0 km by assuming a simple flat-faced rectangular geometry and using densities derived from Apollo lunar samples. We are investigating whether modern 3D modelling techniques in combination with high-resolution topographical and image datasets can reveal additional fine-scale subsurface structure in TLV.

Environmental surveys

International Nuclear Information System (INIS)

Costa-Ribeiro, C.

1977-01-01

An environmental survey conducted in high natural radioactivity areas and methods used to evaluated radiation doses received by the population are presented. It is shown doses absorved due to ingestion of radioactively contaminated food and water. Exposure to external gamma radiation fields or inhalation of abnormal quantities of natural airborne radioactivity are discussed [pt

Goaf water detection using the grounded electrical source airborne transient electromagnetic system

Science.gov (United States)

Li, D.; Ji, Y.; Guan, S.; Wu, Y.; Wang, A.

2017-12-01

To detect the geoelectric characteristic of goaf water, the grounded electrical source airborne transient electromagnetic (GREATEM) system (developed by Jilin University, China) is applied to the goaf water detection since its advantages of considerable prospecting depth, lateral resolution and detection efficiency. For the test of GREATEM system in goaf water detection, an experimental survey was conducted at Qinshui coal mine (Shanxi province, China). After data acquisition, noise reduction and inversion, the resistivity profiles of survey area is presented. The results highly agree the investigation information provided by Shanxi Coal Geology Geophysical Surveying Exploration Institute (China), conforming that the GREATEM system is an effective technique for resistivity detection of goaf water.

Optical Backscattering Measured by Airborne Lidar and Underwater Glider

Directory of Open Access Journals (Sweden)

James H. Churnside

2017-04-01

Full Text Available The optical backscattering from particles in the ocean is an important quantity that has been measured by remote sensing techniques and in situ instruments. In this paper, we compare estimates of this quantity from airborne lidar with those from an in situ instrument on an underwater glider. Both of these technologies allow much denser sampling of backscatter profiles than traditional ship surveys. We found a moderate correlation (R = 0.28, p < 10−5, with differences that are partially explained by spatial and temporal sampling mismatches, variability in particle composition, and lidar retrieval errors. The data suggest that there are two different regimes with different scattering properties. For backscattering coefficients below about 0.001 m−1, the lidar values were generally greater than the glider values. For larger values, the lidar was generally lower than the glider. Overall, the results are promising and suggest that airborne lidar and gliders provide comparable and complementary information on optical particulate backscattering.

Using airborne GAMMA-ray spectrometry (uranium, thorium, potassium) to quantify weathering and erosion processes

International Nuclear Information System (INIS)

Carrier, F.

2005-01-01

The airborne gamma-ray spectrometry survey carried out on the Armorican Massif provided soil contents in U, Th and K in ppm. Chemical and mechanical erosion processes within a homogeneous geological unit have been estimated using their variations and those of the 137 Cs. Our new approach, based on a multivariate analysis (hierarchic ascending classification), integrates the airborne gamma-ray spectrometry data, with their broad spatial distribution, together with precisely located station data (major elements, traces and isotopic geochemistry) resulting from a soil and river water erosion products survey. The total export of potassium was estimated in any point of an area catchment (50-m resolution) until 17+2 t/km 2 /a for a 50-m thick weathering profile. Erosion study by river sampling provide important biases, for the perennial river does not integrate the whole range of erosion products: the geochemical signature of the valleys is currently more represented than plateau areas. (author)

Instrument specifications and geophysical records for airborne electromagnetic survey of parts of Iron, Baraga, and Dickson Counties, Michigan

Science.gov (United States)

Heran, William D.; Smith, Bruce D.

1980-01-01

The data presented herein is from an airborne electromagnetic INPUT* survey conducted by Geoterrex Limited of Canada for the U.S. Geological Survey. The survey area is located in the central part of the Upper Peninsula of Michigan, within parts of Iron, Baraga, and Dickinson Counties. The general area covered is between 46°00' and 46°30' latitude and 88°00' and 88°30' longitude (fig. 1).The INPUT survey was flown as part of a U.S. Geological Survey CUSMAP (Conterminous United States Mineral Appraisal Program) project focusing on the Iron River 2° quadrangle. The survey was flown in order to provide geophysical information which will aid in an integrated geological assessment of mineral potentials of this part of the Iron River 2° quadrangle. The flight line spacing was chosen to maximize the areal coverage without a loss of resolution of major lithologic and structural features.East-west flight lines were flown 400 feet above ground at 1/2 mile intervals. Aerial photos were used for navigation, and the flight path was recorded on continuous-strip film. A continuously recording total field ground magnetic station was used to monitor variations in the Earth's magnetic field. One north-south line was flown to provide a tie for the magnetic data, which was recorded simultaneously with the electromagnetic data by a sensor mounted in the tail of the aircraft. This report is one of two open-file reports. The map in the other report Heran and Smith (1980) shows locations of the fiducial points, the flight lines, preliminary locations of anomalies and conductive zones; all plotted on an air photomosaic. The latitude and longitude ticks marked on this map are only approximate due to distortion in air photos used to recover the flight line position. This map is preliminary and is not to be considered a final interpretation. The present report contains a description of the instrument specifications, a copy of the ground station magnetic data, and a record of the

Massive Gravity

OpenAIRE

de Rham, Claudia

2014-01-01

We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali–Gabadadze–Porrati model (DGP), cascading gravity, and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware–Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally, we present alt...

Polyhedral shape model for terrain correction of gravity and gravity gradient data based on an adaptive mesh

Science.gov (United States)

Guo, Zhikui; Chen, Chao; Tao, Chunhui

2016-04-01

Since 2007, there are four China Da yang cruises (CDCs), which have been carried out to investigate polymetallic sulfides in the southwest Indian ridge (SWIR) and have acquired both gravity data and bathymetry data on the corresponding survey lines(Tao et al., 2014). Sandwell et al. (2014) published a new global marine gravity model including the free air gravity data and its first order vertical gradient (Vzz). Gravity data and its gradient can be used to extract unknown density structure information(e.g. crust thickness) under surface of the earth, but they contain all the mass effect under the observation point. Therefore, how to get accurate gravity and its gradient effect of the existing density structure (e.g. terrain) has been a key issue. Using the bathymetry data or ETOPO1 (http://www.ngdc.noaa.gov/mgg/global/global.html) model at a full resolution to calculate the terrain effect could spend too much computation time. We expect to develop an effective method that takes less time but can still yield the desired accuracy. In this study, a constant-density polyhedral model is used to calculate the gravity field and its vertical gradient, which is based on the work of Tsoulis (2012). According to gravity field attenuation with distance and variance of bathymetry, we present an adaptive mesh refinement and coarsening strategies to merge both global topography data and multi-beam bathymetry data. The local coarsening or size of mesh depends on user-defined accuracy and terrain variation (Davis et al., 2011). To depict terrain better, triangular surface element and rectangular surface element are used in fine and coarse mesh respectively. This strategy can also be applied to spherical coordinate in large region and global scale. Finally, we applied this method to calculate Bouguer gravity anomaly (BGA), mantle Bouguer anomaly(MBA) and their vertical gradient in SWIR. Further, we compared the result with previous results in the literature. Both synthetic model

LAN MAP: An Innovative Airborne Light at Night Mapping Project

Science.gov (United States)

Craine, Eric R.; Craine, B. L.; Craine, E. M.; Craine, P. R.

2013-01-01

Widespread installation of inefficient and misdirected artificial light at night (LAN) has led to increasing concerns about light pollution and its impact, not only on astronomical facilities but larger communities as well. Light pollution impacts scientific research, environmental ecosystems, human health, and quality of life. In recent years, the public policy response to light pollution has included formulation of government codes to regulate lighting design and installation. Various environmental groups now include light pollution among their rallying themes to protest both specific and general developments. The latter efforts are often conducted in the absence of any quantitative data and are frequently charged by emotion rather than reason. To bring some scientific objectivity, and quantitative data, to these discussions, we have developed a suite of tools for simultaneous photometric measurements and temporal monitoring of both local communities and the sky overhead. We have also developed novel protocols for the use of these tools, including a triad of airborne, ground mobile, and ground static photometric surveys. We present a summary of these tools and protocols, with special emphasis on the airborne systems, and discuss baseline and follow-up measurements of LAN environments in the vicinity of numerous observatories in Arizona, the home of the initial LAN MAP surveys.

AVIATR—Aerial Vehicle for In-situ and Airborne Titan Reconnaissance

DEFF Research Database (Denmark)

Barnes, Jason W.; Lemke, Lawrence; Foch, Rick

2012-01-01

We describe a mission concept for a stand-alone Titan airplane mission: Aerial Vehicle for In-situ and Airborne Titan Reconnaissance (AVIATR). With independent delivery and direct-to-Earth communications, AVIATR could contribute to Titan science either alone or as part of a sustained Titan...... Exploration Program. As a focused mission, AVIATR as we have envisioned it would concentrate on the science that an airplane can do best: exploration of Titan's global diversity. We focus on surface geology/hydrology and lower-atmospheric structure and dynamics. With a carefully chosen set of seven...... of a Space Vehicle (SV) for cruise, an Entry Vehicle (EV) for entry and descent, and the Air Vehicle (AV) to fly in Titan's atmosphere. Using an Earth-Jupiter gravity assist trajectory delivers the spacecraft to Titan in 7.5 years, after which the AVIATR AV would operate for a 1-Earth-year nominal mission...

Atom interferometric gravity gradiometer: Disturbance compensation and mobile gradiometry

Science.gov (United States)

Mahadeswaraswamy, Chetan

First ever mobile gravity gradient measurement based on Atom Interferometric sensors has been demonstrated. Mobile gravity gradiometers play a significant role in high accuracy inertial navigation systems in order to distinguish inertial acceleration and acceleration due to gravity. The gravity gradiometer consists of two atom interferometric accelerometers. In each of the accelerometer an ensemble of laser cooled Cesium atoms is dropped and using counter propagating Raman pulses (pi/2-pi-pi/2) the ensemble is split into two states for carrying out atom interferometry. The interferometer phase is proportional to the specific force experienced by the atoms which is a combination of inertial acceleration and acceleration due to gravity. The difference in phase between the two atom interferometric sensors is proportional to gravity gradient if the platform does not undergo any rotational motion. However, any rotational motion of the platform induces spurious gravity gradient measurements. This apparent gravity gradient due to platform rotation is considerably different for an atom interferometric sensor compared to a conventional force rebalance type sensor. The atoms are in free fall and are not influenced by the motion of the case except at the instants of Raman pulses. A model for determining apparent gravity gradient due to rotation of platform was developed and experimentally verified for different frequencies. This transfer function measurement also lead to the development of a new technique for aligning the Raman laser beams with the atom clusters to within 20 mu rad. This gravity gradiometer is situated in a truck for the purpose of undertaking mobile surveys. A disturbance compensation system was designed and built in order to compensate for the rotational disturbances experienced on the floor of a truck. An electric drive system was also designed specifically to be able to move the truck in a uniform motion at very low speeds of about 1cm/s. A 250 x10-9 s-2

Detailed gravity survey to help seismic microzonation: Mapping the thickness of unconsolidated deposits in Ottawa, Canada

Science.gov (United States)

Lamontagne, M.; Thomas, M.; Silliker, J.; Jobin, D.

2011-11-01

In this study, measurements of gravity were made to map and model the thickness of Quaternary deposits (sand and clay) overlying Ordovician limestones in a suburb of Ottawa (Orléans, Ontario). Because ground motion amplification is partly related to the thickness of unconsolidated deposits, this work helps refine the assessment of the earthquake damage potential of the area. It also helps the mapping of clay basins, which can locally exceed 100 m in thickness, where ground motion amplification can occur. Previous work, including well log data and seismic methods, have yielded a wealth of information on near-surface geology in Orléans, thereby providing the necessary constraints to test the applicability of gravity modeling in other locations where other methods cannot always be used. Some 104 gravity stations were occupied in an 8 × 12 km test area in the Orléans. Stations were accurately located with differential GPS that provided centimetric accuracy in elevation. Densities of the unconsolidated Quaternary deposits (Champlain Sea clay) determined on core samples and densities determined on limestone samples from outcrops were used to constrain models of the clay layer overlying the higher density bedrock formations (limestone). The gravity anomaly map delineates areas where clay basins attain > 100 m depth. Assuming a realistic density for the Champlain Sea clays (1.9-2.1 g/cm 3), the thickness over the higher density bedrock formations (Ordovician carbonate rocks) was modeled and compared with well logs and two seismic reflection profiles. The models match quite well with the information determined from well logs and seismic methods. It was found that gravity and the thickness of unconsolidated deposits are correlated but the uncertainties in both data sets preclude the definition of a direct correlation between the two. We propose that gravity measurements at a local scale be used as an inexpensive means of mapping the thickness of unconsolidated deposits

Scales of gravity

International Nuclear Information System (INIS)

Dvali, Gia; Kolanovic, Marko; Nitti, Francesco; Gabadadze, Gregory

2002-01-01

We propose a framework in which the quantum gravity scale can be as low as 10 -3 eV. The key assumption is that the standard model ultraviolet cutoff is much higher than the quantum gravity scale. This ensures that we observe conventional weak gravity. We construct an explicit brane-world model in which the brane-localized standard model is coupled to strong 5D gravity of infinite-volume flat extra space. Because of the high ultraviolet scale, the standard model fields generate a large graviton kinetic term on the brane. This kinetic term 'shields' the standard model from the strong bulk gravity. As a result, an observer on the brane sees weak 4D gravity up to astronomically large distances beyond which gravity becomes five dimensional. Modeling quantum gravity above its scale by the closed string spectrum we show that the shielding phenomenon protects the standard model from an apparent phenomenological catastrophe due to the exponentially large number of light string states. The collider experiments, astrophysics, cosmology and gravity measurements independently point to the same lower bound on the quantum gravity scale, 10 -3 eV. For this value the model has experimental signatures both for colliders and for submillimeter gravity measurements. Black holes reveal certain interesting properties in this framework

Airborne Cloud Computing Environment (ACCE)

Science.gov (United States)

Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

2011-01-01

Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

Increasing the resolution of marine gravity from CryoSat-2 using 20 and 80Hz altimetry

DEFF Research Database (Denmark)

Abulaitijiang, Adili; Andersen, Ole Baltazar

Achieving a high resolution marine gravity field is essential for the derivation of bathymetry, exploring the ocean tectonics, and practically, safe navigation of ships in the poorly surveyed regions. The accuracy of marine gravity can be improved by the improved altimeter range and dense track...

Aerial radiation survey

International Nuclear Information System (INIS)

Pradeep Kumar, K.S.

1998-01-01

Aerial gamma spectrometry surveys are the most effective, comprehensive and preferred tool to delimit the large area surface contamination in a radiological emergency either due to a nuclear accident or following a nuclear strike. The airborne survey apart from providing rapid and economical evaluation of ground contamination over large areas due to larger ground clearance and higher speed, is the only technique to overcome difficulties posed by ground surveys of inaccessible region. The aerial survey technique can also be used for searching of lost radioactive sources, tracking of radioactive plume and generation of background data on the Emergency Planning Zone (EPZ) of nuclear installations

PPN-limit of Fourth Order Gravity inspired by Scalar-Tensor Gravity

OpenAIRE

Capozziello, S.; Troisi, A.

2005-01-01

Based on the {\\it dynamical} equivalence between higher order gravity and scalar-tensor gravity the PPN-limit of fourth order gravity is discussed. We exploit this analogy developing a fourth order gravity version of the Eddington PPN-parameters. As a result, Solar System experiments can be reconciled with higher order gravity, if physical constraints descending from experiments are fulfilled.

Imaging multipole gravity anomaly sources by 3D probability tomography

International Nuclear Information System (INIS)

Alaia, Raffaele; Patella, Domenico; Mauriello, Paolo

2009-01-01

We present a generalized theory of the probability tomography applied to the gravity method, assuming that any Bouguer anomaly data set can be caused by a discrete number of monopoles, dipoles, quadrupoles and octopoles. These elementary sources are used to characterize, in an as detailed as possible way and without any a priori assumption, the shape and position of the most probable minimum structure of the gravity sources compatible with the observed data set, by picking out the location of their centres and peculiar points of their boundaries related to faces, edges and vertices. A few synthetic examples using simple geometries are discussed in order to demonstrate the notably enhanced resolution power of the new approach, compared with a previous formulation that used only monopoles and dipoles. A field example related to a gravity survey carried out in the volcanic area of Mount Etna (Sicily, Italy) is presented, aimed at imaging the geometry of the minimum gravity structure down to 8 km of depth bsl

Terrestrial gravity data analysis for interim gravity model improvement

Science.gov (United States)

1987-01-01

This is the first status report for the Interim Gravity Model research effort that was started on June 30, 1986. The basic theme of this study is to develop appropriate models and adjustment procedures for estimating potential coefficients from terrestrial gravity data. The plan is to use the latest gravity data sets to produce coefficient estimates as well as to provide normal equations to NASA for use in the TOPEX/POSEIDON gravity field modeling program.

Testing Gravity Using Dwarf Stars

OpenAIRE

Sakstein, Jeremy

2015-01-01

Generic scalar-tensor theories of gravity predict deviations from Newtonian physics inside astrophysical bodies. In this paper, we point out that low mass stellar objects, red and brown dwarf stars, are excellent probes of these theories. We calculate two important and potentially observable quantities: the radius of brown dwarfs and the minimum mass for hydrogen burning in red dwarfs. The brown dwarf radius can differ significantly from the GR prediction and upcoming surveys that probe the m...

Airborne gamma-ray spectrometry and computer data processing

International Nuclear Information System (INIS)

Raghuwanshi, S.S.; Bhishma Kumar; Tewari, S.G.

1993-01-01

The physical basis for the measurement of radioelemental concentrations of U, Th, and K on the surface of the earth by airborne gamma-ray spectrometry (AGRS) are described in this paper. The yield of an infinite radioactive plane source for a particular gamma energy helps to know the sampled volume in AGRS, the ground coverage, the ground resolution, the effective planning of the survey, flight line spacing, and sampling time. The infinite source-yield enables the determination of the attenuation coefficients in actual surveys and lays down the criteria for a standard test strip. Scattering of gamma-rays in matter is discussed in order to study its influence in the measurements from air. The theoretical gamma-ray spectrum from terrestrial U, Th, and K are discussed in contrast to its realistic picture which poses problems for their direct use for measurements. The criterion of FWHM (full width at half maximum) and inter-energy distance with their yields is described which finally helps to select the energy windows for (window and MCA) AGRS system. Factors which affect the measurements of radioelemental concentration in AGRS surveys include both correctable and non-correctable ones. Correctable factors are : (a) non-terrestrial sources of gamma-rays aircraft, cosmic, and airborne background (H) (B); (b) interference due to gamma-scattering inter channel effects (l); (c) height variations (H) due to navigation and topography; (d) temperature (T) of ambient air; and (e) pressure (P) of air at flying altitude. For removal of background effects, measurements over test strip and calibration pads are necessary for making the corrections in the order - BIH. These methods are described in the paper. The non-correctable factors include effects, due to terrain moisture, vegetation, and others. The possible ways to eliminate these effects are also briefly described. (author). 17 refs., 13 figs

Mapping of radiation anomalies using UAV mini-airborne gamma-ray spectrometry.

Science.gov (United States)

Šálek, Ondřej; Matolín, Milan; Gryc, Lubomír

2018-02-01

Localization of size-limited gamma-ray anomalies plays a fundamental role in uranium prospecting and environmental studies. Possibilities of a newly developed mini-airborne gamma-ray spectrometric equipment were tested on a uranium anomaly near the village of Třebsko, Czech Republic. The measurement equipment was based on a scintillation gamma-ray spectrometer specially developed for unmanned aerial vehicles (UAV) mounted on powerful hexacopter. The gamma-ray spectrometer has two 103 cm 3 BGO scintillation detectors of relatively high sensitivity. The tested anomaly, which is 80 m by 40 m in size, was investigated by ground gamma-ray spectrometric measurement in a detail rectangular measurement grid. Average uranium concentration is 25 mg/kg eU attaining 700 mg/kg eU locally. The mini-airborne measurement across the anomaly was carried out on three 100 m long parallel profiles at eight flight altitudes from 5 to 40 m above the ground. The resulting 1 s 1024 channel gamma-ray spectra, recorded in counts per second (cps), were processed to concentration units of K, U and Th, while total count (TC) was reported in cps. Increased gamma ray intensity of the anomaly was indicated by mini-airborne measurement at all profiles and altitudes, including the highest altitude of 40 m, at which the recorded intensity is close to the natural radiation background. The reported instrument is able to record data with comparable quality as standard airborne survey, due to relative sensitive detector, lower flight altitude and relatively low flight speed of 1 m/s. The presented experiment brings new experience with using unmanned semi-autonomous aerial vehicles and the latest mini-airborne radiometric instrument. The experiment has demonstrated the instrument's ability to localize size-limited uranium anomalies. Copyright © 2017 Elsevier Ltd. All rights reserved.

A survey of natural terrestrial and airborne radionuclides in moss samples from the peninsular Thailand.

Science.gov (United States)

Wattanavatee, Komrit; Krmar, Miodrag; Bhongsuwan, Tripob

2017-10-01

The aim of this study was to determine the activity concentrations of natural terrestrial radionuclides ( 238 U, 226 Ra, 232 Th and 40 K) and airborne radionuclides ( 210 Pb, 210 Pb ex and 7 Be) in natural terrestrial mosses. The collected moss samples (46) representing 17 species were collected from 17 sampling localities in the National Parks and Wildlife Sanctuaries of Thailand, situated in the mountainous areas between the northern and the southern ends of peninsular Thailand (∼7-12 °N, 99-102 °E). Activity concentrations of radionuclides in the samples were measured using a low background gamma spectrometer. The results revealed non-uniform spatial distributions of all the radionuclides in the study area. Principal component analysis and cluster analysis revealed two distinct origins for the studied radionuclides, and furthermore, the Pearson correlations were strong within 226 Ra, 232 Th, 238 U and 40 K as well as within 210 Pb and 210 Pb ex , but there was no significant correlation between these two groups. Also 7 Be was uncorrelated to the others, as expected due to different origins of the airborne and terrestrial radionuclides. The radionuclide activities of moss samples varied by moss species, topography, geology, and meteorology of each sampling area. The observed abnormally high concentrations of some radionuclides probably indicate that the concentrations of airborne and terrestrial radionuclides in moss samples were directly related to local geological features of the sampling site, or that high levels of 7 Be were most probably linked with topography and regional NE monsoonal winds from mainland China. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ocean tidal loading affecting precise geodetic observations on Greenland: Error account of surface deformations by tidal gravity measurements

DEFF Research Database (Denmark)

Jentzsch, G.; Knudsen, Per; Ramatschi, M.

2000-01-01

Air-borne and satellite based altimetry are used to monitor the Greenland ice-cap. Since these measurements are related to fiducial sites at the coast, the robustness of the height differences depends on the stability of these reference points. To benefit from the accuracy of these methods...... observations. Near the coast ocean tidal loading causes additional vertical deformations in the order of 1 to 10 cm Therefore, tidal gravity measurements were carried out at four fiducial sites around Greenland in order to provide corrections for the kinematic part of the coordinates of these sites. Starting...

Dualities and emergent gravity: Gauge/gravity duality

Science.gov (United States)

de Haro, Sebastian

2017-08-01

In this paper I develop a framework for relating dualities and emergence: two notions that are close to each other but also exclude one another. I adopt the conception of duality as 'isomorphism', from the physics literature, cashing it out in terms of three conditions. These three conditions prompt two conceptually different ways in which a duality can be modified to make room for emergence; and I argue that this exhausts the possibilities for combining dualities and emergence (via coarse-graining). I apply this framework to gauge/gravity dualities, considering in detail three examples: AdS/CFT, Verlinde's scheme, and black holes. My main point about gauge/gravity dualities is that the theories involved, qua theories of gravity, must be background-independent. I distinguish two senses of background-independence: (i) minimalistic and (ii) extended. I argue that the former is sufficiently strong to allow for a consistent theory of quantum gravity; and that AdS/CFT is background-independent on this account; while Verlinde's scheme best fits the extended sense of background-independence. I argue that this extended sense should be applied with some caution: on pain of throwing the baby (general relativity) out with the bath-water (extended background-independence). Nevertheless, it is an interesting and potentially fruitful heuristic principle for quantum gravity theory construction. It suggests some directions for possible generalisations of gauge/gravity dualities. The interpretation of dualities is discussed; and the so-called 'internal' vs. 'external' viewpoints are articulated in terms of: (i) epistemic and metaphysical commitments; (ii) parts vs. wholes. I then analyse the emergence of gravity in gauge/gravity dualities in terms of the two available conceptualisations of emergence; and I show how emergence in AdS/CFT and in Verlinde's scenario differ from each other. Finally, I give a novel derivation of the Bekenstein-Hawking black hole entropy formula based on

The potential of quantum technology gravity sensors in civil engineering

Science.gov (United States)

Tuckwell, G.; Metje, N.; Boddice, D.; Usher, C.

2017-12-01

Potential field techniques have advantages over active geophysical techniques as they are not limited to the depth they can image features, provided the signals of interest are detectable amongst the other variations recorded by the instrument. A new generation of gravity instruments based on quantum technology promise greatly increased measurement sensitivity, but with this comes significant challenges in data processing and noise suppression. In the UK Innovate UK funded SIGMA project (http://www.rsksigma.co.uk/) the field of opportunity for a step change in gravity sensor accuracy has been evaluated by comparison with existing geophysical sensors, identifying the range of targets and depths of interest to commercial end users that are currently undetectable and might become visible. Forward modelling was used to quantify the potential of a Quantum Technology (QT) gravity and gravity gradiometer sensor. A substantive improvement in detectability of targets is predicted, which can be considered as a factor of 1.5 to 2 increase in the depth of detectability, or in the reduction of the size of the feature of interest. To take further advantage of new instrument sensitivity, new survey workflows are required. The accuracy of measured gravity maps is limited by environmental vibration noise, and by the accuracy with which tidal variations and terrain signals can be removed. It is still common practice in engineering scale surveys for gravity values to be reduced to Bouguer residuals. However, with a more sensitive instrument comes the need to measure the terrain more accurately. This can be achieved within a commercially viable workflow using a laser scanner for rapid data acquisition and advanced processing to produce an accurate DEM. Initial tests on 4 commercial sites have shown that an improvement of 10s of mGal can be achieved if applying a full digital terrain model correction to the microgravity data even on sites with very minor topographic height variations

Optimization of a Time-Lapse Gravity Network for Carbon Sequestration

Science.gov (United States)

Appriou, D.; Strickland, C. E.; Ruprecht Yonkofski, C. M.

2017-12-01

The objective of this study is to evaluate what could be a comprehensive and optimal state of the art gravity monitoring network that would meet the UIC class VI regulation and insure that 90% of the CO2 injected remain underground. Time-lapse gravity surveys have a long history of effective applications of monitoring temporal density changes in the subsurface. For decades, gravity measurements have been used for a wide range of applications. The interest of time-lapse gravity surveys for monitoring carbon sequestration sites started recently. The success of their deployment in such sites depends upon a combination of favorable conditions, such as the reservoir geometry, depth, thickness, density change over time induced by the CO2 injection and the location of the instrument. In most cases, the density changes induced by the CO2 plume in the subsurface are not detectable from the surface but the use of borehole gravimeters can provide excellent results. In the framework of the National Assessment and Risk Partnership (NRAP) funded by the Department of Energy, the evaluation of the effectiveness of the gravity monitoring of a CO2 storage site has been assessed using multiple synthetic scenarios implemented on a community model developed for the Kimberlina site (e.g., fault leakage scenarios, borehole leakage). The Kimberlina carbon sequestration project was a pilot project located in southern San Joaquin Valley, California, aimed to safely inject 250,000 t CO2/yr for four years. Although the project was cancelled in 2012, the site characterization efforts resulted in the development of a geologic model. In this study, we present the results of the time-lapse gravity monitoring applied on different multiphase flow and reactive transport models developed by Lawrence Berkeley National Laboratory (i.e., no leakage, permeable fault zone, wellbore leakage). Our monitoring approach considers an ideal network, consisting of multiple vertical and horizontal instrumented

Monitoring and evaluation techniques for airborne contamination

Energy Technology Data Exchange (ETDEWEB)

Yihua, Xia [China Inst. of Atomic Energy, Beijing (China)

1997-06-01

Monitoring and evaluation of airborne contamination are of great importance for the purpose of protection of health and safety of workers in nuclear installations. Because airborne contamination is one of the key sources to cause exposure to individuals by inhalation and digestion, and to cause diffusion of contaminants in the environment. The main objectives of monitoring and evaluation of airborne contamination are: to detect promptly a loss of control of airborne material, to help identify those individuals and predict exposure levels, to assess the intake and dose commitment to the individuals, and to provide sufficient documentation of airborne radioactivity. From the viewpoint of radiation protection, the radioactive contaminants in air can be classified into the following types: airborne aerosol, gas and noble gas, and volatile gas. In this paper, the following items are described: sampling methods and techniques, measurement and evaluation, and particle size analysis. (G.K.)

Monitoring and evaluation techniques for airborne contamination

International Nuclear Information System (INIS)

Xia Yihua

1997-01-01

Monitoring and evaluation of airborne contamination are of great importance for the purpose of protection of health and safety of workers in nuclear installations. Because airborne contamination is one of the key sources to cause exposure to individuals by inhalation and digestion, and to cause diffusion of contaminants in the environment. The main objectives of monitoring and evaluation of airborne contamination are: to detect promptly a loss of control of airborne material, to help identify those individuals and predict exposure levels, to assess the intake and dose commitment to the individuals, and to provide sufficient documentation of airborne radioactivity. From the viewpoint of radiation protection, the radioactive contaminants in air can be classified into the following types: airborne aerosol, gas and noble gas, and volatile gas. In this paper, the following items are described: sampling methods and techniques, measurement and evaluation, and particle size analysis. (G.K.)

Contravariant gravity on Poisson manifolds and Einstein gravity

International Nuclear Information System (INIS)

Kaneko, Yukio; Watamura, Satoshi; Muraki, Hisayoshi

2017-01-01

A relation between gravity on Poisson manifolds proposed in Asakawa et al (2015 Fortschr. Phys . 63 683–704) and Einstein gravity is investigated. The compatibility of the Poisson and Riemann structures defines a unique connection, the contravariant Levi-Civita connection, and leads to the idea of the contravariant gravity. The Einstein–Hilbert-type action yields an equation of motion which is written in terms of the analog of the Einstein tensor, and it includes couplings between the metric and the Poisson tensor. The study of the Weyl transformation reveals properties of those interactions. It is argued that this theory can have an equivalent description as a system of Einstein gravity coupled to matter. As an example, it is shown that the contravariant gravity on a two-dimensional Poisson manifold can be described by a real scalar field coupled to the metric in a specific manner. (paper)

Surveying and assessing the hazards associated with the processing of uranium

International Nuclear Information System (INIS)

Kruger, J.

1980-01-01

The control of uranium during the milling process has not received extensive attention. The results of several surveys of surface contamination, airborne contamination and external radiation made at South African processing facilities are presented and compared with derived norms for permissible exposure to uranium dust. The routine urine sampling results are used as an indicator of personnel exposures. Results of sampling identify the main sources of airborne activity and indicate the contribution of general surface contamination levels to airborne levels. The use of surface contamination levels together with frequent air sampling for assessing the environmental conditions is illustrated. It is concluded that infrequent grab air sampling alone is not adequate for assessing the hazards during uranium processing. Detailed surveys are required and proper area and personnel access control are indicated. (H.K.)

Active airborne contamination control using electrophoresis

International Nuclear Information System (INIS)

Veatch, B.D.

1994-01-01

In spite of our best efforts, radioactive airborne contamination continues to be a formidable problem at many of the Department of Energy (DOE) weapons complex sites. For workers that must enter areas with high levels of airborne contamination, personnel protective equipment (PPE) can become highly restrictive, greatly diminishing productivity. Rather than require even more restrictive PPE for personnel in some situations, the Rocky Flats Plant (RFP) is actively researching and developing methods to aggressively combat airborne contamination hazards using electrophoretic technology. With appropriate equipment, airborne particulates can be effectively removed and collected for disposal in one simple process. The equipment needed to implement electrophoresis is relatively inexpensive, highly reliable, and very compact. Once airborne contamination levels are reduced, less PPE is required and a significant cost savings may be realized through decreased waste and maximized productivity. Preliminary ''cold,'' or non-radioactive, testing results at the RFP have shown the technology to be effective on a reasonable scale, with several potential benefits and an abundance of applications

BOOK REVIEW: Canonical Gravity and Applications: Cosmology, Black Holes, and Quantum Gravity Canonical Gravity and Applications: Cosmology, Black Holes, and Quantum Gravity

Science.gov (United States)

Husain, Viqar

2012-03-01

book are also covered in detail, and with more worked examples, in the former book, and the entire focus of the latter is Bianchi models. After a brief introduction outlining the aim of the book, the second chapter provides the canonical theory of homogeneous isotropic cosmology with scalar matter; this covers the basics and linear perturbation theory, and is meant as a first taste of what is to come. The next chapter is a thorough introduction of the canonical formulation of general relativity in both the ADM and Ashtekar-Barbero variables. This chapter contains details useful for graduate students which are either scattered or missing in the literature. Applications of the canonical formalism are in the following chapter. These cover standard material and techniques for obtaining mini(midi)-superspace models, including the Bianchi and Gowdy cosmologies, and spherically symmetric reductions. There is also a brief discussion of the two-dimensional dilaton gravity. The spherically symmetric reduction is presented in detail also in the connection-triad variables. The chapter on global and asymptotic properties gives introductions to geodesic and null congruences, trapped surfaces, a survey of singularity theorems, horizons and asymptotic properties. The chapter ends with a discussion of junction conditions and the Vaidya solution. As already mentioned, this material is covered in detail in Poisson's book. The final chapter on quantization describes and contrasts the Dirac and reduced phase space methods. It also gives an introduction to background independent quantization using the holonomy-flux operators, which forms the basis of the LQG program. The application of this method to cosmology and its affect on the Friedmann equation is covered next, followed by a brief introduction to the effective constraint method, which is another area developed by the author. I think this book is a useful addition to the literature for graduate students, and potentially also for

ZPR-9 airborne plutonium monitoring system

International Nuclear Information System (INIS)

Rusch, G.K.; McDowell, W.P.; Knapp, W.G.

1975-01-01

An airborne plutonium monitoring system which is installed in the ZPR-9 (Zero Power Reactor No. 9) facility at Argonne National Laboratory is described. The design and operational experience are discussed. This monitoring system utilizes particle size and density discrimination, alpha particle energy discrimination, and a background-subtraction techique operating in cascade to separate airborne-plutonium activity from other, naturally occurring, airborne activity. Relatively high sensitivity and reliability are achieved

Is nonrelativistic gravity possible?

International Nuclear Information System (INIS)

Kocharyan, A. A.

2009-01-01

We study nonrelativistic gravity using the Hamiltonian formalism. For the dynamics of general relativity (relativistic gravity) the formalism is well known and called the Arnowitt-Deser-Misner (ADM) formalism. We show that if the lapse function is constrained correctly, then nonrelativistic gravity is described by a consistent Hamiltonian system. Surprisingly, nonrelativistic gravity can have solutions identical to relativistic gravity ones. In particular, (anti-)de Sitter black holes of Einstein gravity and IR limit of Horava gravity are locally identical.

Software for airborne radiation monitoring system

International Nuclear Information System (INIS)

Sheinfeld, M.; Kadmon, Y.; Tirosh, D.; Elhanany, I.; Gabovitch, A.; Barak, D.

1997-01-01

The Airborne Radiation Monitoring System monitors radioactive contamination in the air or on the ground. The contamination source can be a radioactive plume or an area contaminated with radionuclides. This system is composed of two major parts: Airborne Unit carried by a helicopter, and Ground Station carried by a truck. The Airborne software is intended to be the core of a computerized airborne station. The software is written in C++ under MS-Windows with object-oriented methodology. It has been designed to be user-friendly: function keys and other accelerators are used for vital operations, a help file and help subjects are available, the Human-Machine-Interface is plain and obvious. (authors)

Gravity-matter entanglement in Regge quantum gravity

International Nuclear Information System (INIS)

Paunković, Nikola; Vojinović, Marko

2016-01-01

We argue that Hartle-Hawking states in the Regge quantum gravity model generically contain non-trivial entanglement between gravity and matter fields. Generic impossibility to talk about “matter in a point of space” is in line with the idea of an emergent spacetime, and as such could be taken as a possible candidate for a criterion for a plausible theory of quantum gravity. Finally, this new entanglement could be seen as an additional “effective interaction”, which could possibly bring corrections to the weak equivalence principle. (paper)

Using NASA`s Airborne Topographic Mapper IV to Quantify Geomorphic Change in Arid Southwestern Stream Systems

Science.gov (United States)

Finnegan, D. C.; Krabill, W.; Lichvar, R. W.; Ericsson, M. P.; Frederick, E.; Manizade, S.; Yungel, J.; Sonntag, J.; Swift, R.

2005-12-01

Understanding how arid stream systems respond to individual climatic events is often difficult given the dynamic and `flashy' nature of most watersheds and the unpredictable nature of individual storm events. Until recently conventional methods for quantifying change dictated the use of stream gauge measurements coupled with periodic cross-section measurements to quantify changes in large-scale channel geometry. Using this approach to quantify change across large areas often proves to be impractical and unattainable given the laborious nature of most surveying techniques including modern GPS systems. Alternately, airborne laser technologies such as NASA's Airborne Topographic Mapper (ATM) are capable of quantifying small-scale changes (~5-10cm) across large-scale terrain rapidly and accurately. The ATM was developed at the NASA-GSFC Wallops Flight Facility. Its current version, ATM-4, measures topography 5,000 times per second across a 45-degree swath below the aircraft by transmitting a 532nm (green) laser pulse and receiving the backscattered signal in a high-speed waveform digitizer. The laser range measurements are combined with aircraft location from GPS and attitude from an inertial navigation system (INS) to provide a precise XYZ coordinate for each (~1-meter diameter) laser footprint on the ground. Our work focuses on the use of airborne laser altimetry to quantify the nature of individual surfaces and the geomorphic change that occurs within small arid stream systems during significant storm events. In September of 2003 and 2005 acquisition surveys using NASA's ATM-IV were flown over Mission Creek, a small arid stream system in Southern California's Mojave Desert with a relatively long gauging history (>40yrs), allowing us to quantify the geomorphic change occurring within the channel as a result of the record storm events during the winter of 2004-2005. Preliminary results associated with our work are encouraging and lead us to believe that when compared

Airborne remote sensing of estuarine intertidal radionuclide concentrations

International Nuclear Information System (INIS)

Rainey, M.P.

1999-08-01

The ability to map industrial discharges through remote sensing provides a powerful tool in environmental monitoring. Radionuclide effluents have been discharged, under authorization, into the Irish Sea from BNFL (British Nuclear Fuels Pic.) sites at Sellafield and Springfields since 1952. The quantitative mapping of this anthropogenic radioactivity in estuarine intertidal zones is crucial for absolute interpretations of radionuclide transport. The spatial resolutions of traditional approaches e.g. point sampling and airborne gamma surveys are insufficient to support geomorphic interpretations of the fate of radionuclides in estuaries. The research presented in this thesis develops the use of airborne remote sensing to derive high-resolution synoptic data on the distribution of anthropogenic radionuclides in the intertidal areas of the Ribble Estuary, Lancashire, UK. From multidate surface sediment samples a significant relationship was identified between the Sellafield-derived 137 Cs and 241 Am and clay content (r 2 = 0.93 and 0.84 respectively). Detailed in situ, and laboratory, reflectance (0.4-2.5μm) experiments demonstrated that significant relationships exist between Airborne Thematic Mapper (ATM) simulated reflectance and intertidal sediment grain-size. The spectral influence of moisture on the reflectance characteristics of the intertidal area is also evident. This had substantial implications for the timing of airborne image acquisition. Low-tide Daedalus ATM imagery (Natural Environmental Research Council) was collected of the Ribble Estuary on May 30th 1997. Preprocessing and linear unmixing of the imagery allowed accurate sub-pixel determinations of sediment clay content distributions (r 2 = 0.81). Subsequently, the established relationships between 137 Cs and 241 Am and sediment grain-size enabled the radionuclide activity distributions across the entire intertidal area (92 km 2 ) to be mapped at a geomorphic scale (1.75 m). The accuracy of these maps

Lovelock gravities from Born-Infeld gravity theory

Science.gov (United States)

Concha, P. K.; Merino, N.; Rodríguez, E. K.

2017-02-01

We present a Born-Infeld gravity theory based on generalizations of Maxwell symmetries denoted as Cm. We analyze different configuration limits allowing to recover diverse Lovelock gravity actions in six dimensions. Further, the generalization to higher even dimensions is also considered.

Astrophysical tests of gravity: a screening map of the nearby universe

Energy Technology Data Exchange (ETDEWEB)

Cabré, Anna; Vikram, Vinu; Jain, Bhuvnesh [Center for Particle Cosmology, Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104-6396 (United States); Zhao, Gong-Bo; Koyama, Kazuya, E-mail: annanusca@gmail.com, E-mail: vinu@sas.upenn.edu, E-mail: gong-bo.zhao@port.ac.uk, E-mail: bjain@physics.upenn.edu, E-mail: Kazuya.Koyama@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom)

2012-07-01

Astrophysical tests of modified gravity theories in the nearby universe have been emphasized recently by Hui 2009 and Jain 2011. A key element of such tests is the screening mechanism whereby general relativity is restored in massive halos or high density environments like the Milky Way. In chameleon theories of gravity, including all f(R) models, field dwarf galaxies may be unscreened and therefore feel an extra force, as opposed to screened galaxies. The first step to study differences between screened and unscreened galaxies is to create a 3D screening map. We use N-body simulations to test and calibrate simple approximations to determine the level of screening in galaxy catalogs. Sources of systematic errors in the screening map due to observational inaccuracies are modeled and their contamination is estimated. We then apply our methods to create a map out to 200 Mpc in the Sloan Digital Sky Survey footprint using data from the Sloan survey and other sources. In two companion papers this map will be used to carry out new tests of gravity using distance indicators and the disks of dwarf galaxies. We also make our screening map publicly available.

Euler–Chern–Simons gravity from Lovelock–Born–Infeld gravity

OpenAIRE

Izaurieta, F.; Rodriguez, E.; Salgado, P.

2004-01-01

In the context of a gauge theoretical formulation, higher dimensional gravity invariant under the AdS group is dimensionally reduced to Euler-Chern-Simons gravity. The dimensional reduction procedure of Grignani-Nardelli [Phys. Lett. B 300, 38 (1993)] is generalized so as to permit reducing D-dimensional Lanczos Lovelock gravity to d=D-1 dimensions.

Survey monitoring of environmental radioactivity in Busan area

Energy Technology Data Exchange (ETDEWEB)

Yang, H. S.; Lee, J. [Busan Regional Monitoring Station, Busan (Korea, Republic of)

2000-12-15

At Pusan Regional Monitoring Station in Busan have been measured periodically in 2000 gross beta activities in the airborne dust, fallout, precipitation and tap water and gamma exposure rates. Gamma nuclides in airborne dust, fallout and precipitation have also been monitored at the station. As a part of environmental radiation/radioactivity distribution survey around Pusan, vegetables, fishes, shellfish, drinking water (total 23ea) samples were taken from sampling sites which were selected by KlNS. We analysis gamma nuclide for all. No significant changes from the previous survey have been found in both beta activities and gamma exposure rates. As the results of analyzing an gamma nuclide concentration in environmental samples in Pusan are fee of radiological contaminants.

Survey monitoring of environmental radioactivity in Busan area

Energy Technology Data Exchange (ETDEWEB)

Yang, Han Soeb; Jang, Young A. [Busan Regional Monitoring Station, Busan (Korea, Republic of)

2003-12-15

At Regional Radioactivity Monitoring Station in Pusan have been measured periodically in 2003 gross beta activities in the airborne dust, fallout, precipitation and tap water and gamma exposure rates. Gamma nuclides in airborne dust, fallout and precipitation have also been monitored at the station. As a part of environmental radiation/radioactivity distribution survey around Busan foodstuffs, dust, drinking water (total 24ea) samples were taken from sampling sites which were selected by KINS. We analysis gamma nuclide for all. No significant changes from the previous survey have been found in both beta activities and gamma exposure rates. As the results of analyzing an gamma nuclide concentration in environmental samples in Pusan are fee of radiological contaminants.

Survey monitoring of environmental radioactivity in Busan area

International Nuclear Information System (INIS)

Yang, Han Soeb; Jang, Young A.

2003-12-01

At Regional Radioactivity Monitoring Station in Pusan have been measured periodically in 2003 gross beta activities in the airborne dust, fallout, precipitation and tap water and gamma exposure rates. Gamma nuclides in airborne dust, fallout and precipitation have also been monitored at the station. As a part of environmental radiation/radioactivity distribution survey around Busan foodstuffs, dust, drinking water (total 24ea) samples were taken from sampling sites which were selected by KINS. We analysis gamma nuclide for all. No significant changes from the previous survey have been found in both beta activities and gamma exposure rates. As the results of analyzing an gamma nuclide concentration in environmental samples in Pusan are fee of radiological contaminants

Estimating Moho basement and faults using gravity inversion in Yushu-earthquake area, China

Directory of Open Access Journals (Sweden)

Yang Guangliang

2012-05-01

Full Text Available A gravity survey was conducted one month after the 2010 Yushu earthquake in the epicenter area. The cross-fault survey line was 500 km long, from Langqian county to Qingshuihe county, in a transition zone between Bayan Har block and Qiangtang block, in an area of high elevation, large undulating terrain, and complex geological features. An interpretation of the data was carried out together with other kinds of data, such as seismic exploration and magnetic exploration. The result shows that gravity is sensitive to fault boundary; the geologic structure of the region is complex at middle and upper depths, and the density profile reveals an eastward-pushing fault movement.

The propagation of orographic gravity waves into the stratosphere. Linear theory, idealized and realistic numerical simulation; Die Ausbreitung orographisch angeregter Schwerewellen in die Stratosphaere. Lineare Theorie, idealisierte und realitaetsnahe numerische Simulation

Energy Technology Data Exchange (ETDEWEB)

Leutbecher, M. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Wessling (Germany). Inst. fuer Physik der Atmosphaere

1998-07-01

Flow over mountains in the stably stratified atmosphere excites gravity waves. The three-dimensional propagation of these waves into the stratosphere is studied using linear theority as well as idealized and realistic numerical simulations. Stagnation, momentum fluxes and temperature anomalies are analyzed for idealized types of flow. Isolated mountains with elliptical contours are considered. The unperturbed atmosphere has constant wind speed and constant static stability or two layers (troposphere/stratosphere) of constant stability each. Real flow over orography is investigated where gravity waves in the stratosphere have been observed. Characteristics of the gravity wave event over the southern tip of Greenland on 6 January 1992 were recorded on a flight of the ER-2 at an altitude of 20 km. In the second case polar stratospheric clouds (PSC) were observed by an airborne Lidar over Northern Scandinavia on 9 January 1997. The PSC were induced by temperature anomalies in orographic gravity waves. (orig.)

Gravity

CERN Document Server

Gamow, George

2003-01-01

A distinguished physicist and teacher, George Gamow also possessed a special gift for making the intricacies of science accessible to a wide audience. In Gravity, he takes an enlightening look at three of the towering figures of science who unlocked many of the mysteries behind the laws of physics: Galileo, the first to take a close look at the process of free and restricted fall; Newton, originator of the concept of gravity as a universal force; and Einstein, who proposed that gravity is no more than the curvature of the four-dimensional space-time continuum.Graced with the author's own draw

ESA CryoVEx 2014 - Airborne ASIRAS radar and laser scanner measurements during 2014 CryoVEx campaign in the Arctic

DEFF Research Database (Denmark)

Hvidegaard, S. M.; Nielsen, J. E.; Sørensen, L. Sandberg

the penetration depth of the ASIRAS radar. An opportunity site on the Greenland Ice Sheet was surveyed near Jakobshavn Isbræ. No other ground experiments were coordinated with the CryoVEx campaing on the Greenland Ice Sheet. The CryoVEx 2014 campaign was a success and the processed data is of high quality......This report outlines the airborne field operations with the ESA airborne Ku‐band interferometric radar (ASIRAS), coincident airborne laser scanner (ALS) and vertical photography to acquire data over sea‐ and land ice along validation sites and CryoSat‐2 ground tracks. The airborne campaign...... in the Beaufort Sea lead by US office of Naval Research (ONR) and north of Greenland as a dedicated ESA CryoVEx initiative. In addition, selected CryoSat‐2 ground tracks were under‐flown in the Lincoln Sea from CFS Alert, North of Greenland and Svalbard from St. Nord and Longyearbyen. Several of the flights...

Gravity field and structure of the Sorong Fault Zone, eastern Indonesia

Science.gov (United States)

Sardjono

Gravity surveys along coastlines of islands in the region Banggai-Sula, Eastern Sulawesi, Halmahera, Bacan and Obi were carried out as part of the Sorong Fault Zone Project. Results of the Surveys were integrated with gravity data previously acquired by other projects, including on-land gravity data from the Bird Head area Irian Jaya (Dow et al 1986), Seram Island (Milsom 1977), Buru Island (Oemar and Reminton 1993) and Central Sulawesi (Silver et al. 1983) as well as marine gravity information within and surrounding the Sorong Fault Zone (Bowin et al. 1980). Gravity expeditions of the Sorong Fault Zone Project also include measurements in Mayu Island and the island group of Talaud, situated further north in the Central Molucca Sea region. A total of one hundred and forty two gravity data were acquired in the region of Banggai-Sula islands, forty seven in eastern part of Central Sulawesi, about four hundred in Halmahera, Bacan and Obi, and seventy nine in Mayu and Talaud. Surveys in the eastern part of Central Sulawesi were carried out for the purpose of tieing the older gravity data obtained from Silver et al. (1983) and the more recent data of the Sorong Fault Zone Project. About one thousand thirty hundred and thirty gravity data were acquired as part of the Irian Jaya Geological Mapping Project (IJGMP) in the period of 1978-1983, a project commissioned by the Indonesian Geological Research and Development Centre (GRDC) and the Australian Bureau of Mineral Resources (BMR). The remoteness of the survey areas of the Sorong Fault Zone Project necessitated a careful planning for travel arrangements and provision of logistics. A wide range of magnitude of gravity field was observed in the Sorong Fault Zone, extending from values below -250 mGal recorded in the southern part of the Molucca Sea to values in excess of +320 mGal measured near to sea level in the coastal areas south of Mangole and north of Sulabesi, the two islands of the Sula Group. Steep gradients of

Lower dimensional gravity

International Nuclear Information System (INIS)

Brown, J.D.

1988-01-01

This book addresses the subject of gravity theories in two and three spacetime dimensions. The prevailing philosophy is that lower dimensional models of gravity provide a useful arena for developing new ideas and insights, which are applicable to four dimensional gravity. The first chapter consists of a comprehensive introduction to both two and three dimensional gravity, including a discussion of their basic structures. In the second chapter, the asymptotic structure of three dimensional Einstein gravity with a negative cosmological constant is analyzed. The third chapter contains a treatment of the effects of matter sources in classical two dimensional gravity. The fourth chapter gives a complete analysis of particle pair creation by electric and gravitational fields in two dimensions, and the resulting effect on the cosmological constant

Airborne iodine-125 arising from surface contamination

International Nuclear Information System (INIS)

Kwok, C.S.; Hilditch, T.E.

1982-01-01

Measurements of airborne 125 I were made during the subdivision of 740 MBq stocks of 125 I iodide solution in a hospital dispensary. Within the fume cupboard the mean airborne 125 I concentration was 3.5 +- 2.9 kBqm -3 . No airborne concentration contamination was found outside the fume cupboard during these dispensing sessions. The airborne 125 I concentration arising from deliberate surface contamination (50 μl, 3.7-6.3 MBq) of the top of a lead pot was measured at a height simulating face level at an open work bench. There was a progressive fall in airborne concentration over seven days but even then the level was still significantly above background. Measurements made with the extraction system of the fume cupboard in operation were 2-3 times lower. (U.K.)

Lovelock gravities from Born–Infeld gravity theory

Directory of Open Access Journals (Sweden)

P.K. Concha

2017-02-01

Full Text Available We present a Born–Infeld gravity theory based on generalizations of Maxwell symmetries denoted as Cm. We analyze different configuration limits allowing to recover diverse Lovelock gravity actions in six dimensions. Further, the generalization to higher even dimensions is also considered.

Large-scale radon hazard evaluation in the Oslofjord region of Norway utilizing indoor radon concentrations, airborne gamma ray spectrometry and geological mapping

International Nuclear Information System (INIS)

Smethurst, Mark Andrew; Strand, Terje; Sundal, Aud Venke; Rudjord, Anne Liv

2008-01-01

We test whether airborne gamma ray spectrometer measurements can be used to estimate levels of radon hazard in the Oslofjord region of Norway. We compile 43,000 line kilometres of gamma ray spectrometer data from 8 airborne surveys covering 10,000 km 2 and compare them with 6326 indoor radon measurements. We find a clear spatial correlation between areas with elevated concentrations of uranium daughters in the near surface of the ground and regions with high incidence of elevated radon concentrations in dwellings. This correlation permits cautious use of the airborne data in radon hazard evaluation where direct measurements of indoor radon concentrations are few or absent. In radon hazard evaluation there is a natural synergy between the mapping of radon in indoor air, bedrock and drift geology mapping and airborne gamma ray surveying. We produce radon hazard forecast maps for the Oslofjord region based on a spatial union of hazard indicators from all four of these data sources. Indication of elevated radon hazard in any one of the data sets leads to the classification of a region as having an elevated radon hazard potential. This approach is inclusive in nature and we find that the majority of actual radon hazards lie in the assumed elevated risk regions

AERIAL RADIOLOGICAL SURVEYS

International Nuclear Information System (INIS)

Proctor, A.E.

1997-01-01

Measuring terrestrial gamma radiation from airborne platforms has proved to be a useful method for characterizing radiation levels over large areas. Over 300 aerial radiological surveys have been carried out over the past 25 years including U.S. Department of Energy (DOE) sites, commercial nuclear power plants, Formerly Utilized Sites Remedial Action Program/Uranium Mine Tailing Remedial Action Program (FUSRAP/UMTRAP) sites, nuclear weapons test sites, contaminated industrial areas, and nuclear accident sites. This paper describes the aerial measurement technology currently in use by the Remote Sensing Laboratory (RSL) for routine environmental surveys and emergency response activities. Equipment, data-collection and -analysis methods, and examples of survey results are described

Airborne radionuclides in the proglacial environment as indicators of sources and transfers of soil material.

Science.gov (United States)

Łokas, Edyta; Wachniew, Przemysław; Jodłowski, Paweł; Gąsiorek, Michał

2017-11-01

A survey of artificial ( 137 Cs, 238 Pu, 239+240 Pu, 241 Am) and natural ( 226 Ra, 232 Th, 40 K, 210 Pb) radioactive isotopes in proglacial soils of an Arctic glacier have revealed high spatial variability of activity concentrations and inventories of the airborne radionuclides. Soil column 137 Cs inventories range from below the detection limit to nearly 120 kBq m -2 , this value significantly exceeding direct atmospheric deposition. This variability may result from the mixing of materials characterised by different contents of airborne radionuclides. The highest activity concentrations observed in the proglacial soils may result from the deposition of cryoconites, which have been shown to accumulate airborne radionuclides on the surface of glaciers. The role of cryoconites in radionuclide accumulation is supported by the concordant enrichment of the naturally occurring airborne 210 Pb in proglacial soil cores showing elevated levels of artificial radionuclides. The lithogenic radionuclides show less variability than the airborne radionuclides because their activity concentrations are controlled only by the mixing of material derived from the weathering of different parent rocks. Soil properties vary little within and between the profiles and there is no unequivocal relationship between them and the radionuclide contents. The inventories reflect the pathways and time variable inputs of soil material to particular sites of the proglacial zone. Lack of the airborne radionuclides reflects no deposition of material exposed to the atmosphere after the 1950s or its removal by erosion. Inventories above the direct atmospheric deposition indicate secondary deposition of radionuclide-bearing material. Very high inventories indicate sites where transport pathways of cryoconite material terminated. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Distribution of airborne fungi, particulate matter and carbon dioxide in Seoul metropolitan subway stations].

Science.gov (United States)

Kim, Ki Youn; Park, Jae Beom; Kim, Chi Nyon; Lee, Kyung Jong

2006-07-01

The aims of this study were to examine the level of airborne fungi and environmental factors in Seoul metropolitan subway stations and to provide fundamental data to protect the health of subway workers and passengers. The field survey was performed from November in 2004 to February in 2005. A total 22 subway stations located at Seoul subway lines 1-4 were randomly selected. The measurement points were subway workers' activity areas (station office, bedroom, ticket office and driver's seat) and the passengers' activity areas (station precincts, inside train and platform). Air sampling for collecting airborne fungi was carried out using a one-stage cascade impactor. The PM and CO2 were measured using an electronic direct recorder and detecting tube, respectively. In the activity areas of the subway workers and passengers, the mean concentrations of airborne fungi were relatively higher in the workers' bedroom and station precinct whereas the concentration of particulate matter, PM10 and PM2.5, were relatively higher in the platform, inside the train and driver's seat than in the other activity areas. There was no significant difference in the concentration of airborne fungi between the underground and ground activity areas of the subway. The mean PM10 and PM2.5 concentration in the platform located at underground was significantly higher than that of the ground (psubway line 1-4 were not serious enough to cause respiratory disease in subway workers and passengers. This indicates that there is little correlation between airborne fungi and particulate matter.

Nonlocal gravity

CERN Document Server

Mashhoon, Bahram

2017-01-01

Relativity theory is based on a postulate of locality, which means that the past history of the observer is not directly taken into account. This book argues that the past history should be taken into account. In this way, nonlocality---in the sense of history dependence---is introduced into relativity theory. The deep connection between inertia and gravitation suggests that gravity could be nonlocal, and in nonlocal gravity the fading gravitational memory of past events must then be taken into account. Along this line of thought, a classical nonlocal generalization of Einstein's theory of gravitation has recently been developed. A significant consequence of this theory is that the nonlocal aspect of gravity appears to simulate dark matter. According to nonlocal gravity theory, what astronomers attribute to dark matter should instead be due to the nonlocality of gravitation. Nonlocality dominates on the scale of galaxies and beyond. Memory fades with time; therefore, the nonlocal aspect of gravity becomes wea...

Spectrometric aerial survey as a new tool for geological survey and mining prospecting

International Nuclear Information System (INIS)

Cambon, R.

1997-01-01

Airborne survey for radioactive minerals started around 1945. The limited sensitivity of the tools used, the difficulties found for the topographic and training effect corrections, made difficult the evaluation of the results. The technical progresses realized in the recent past years in electronic and computer sciences allowed to overcome these difficulties and gave to the method all its potentialities. With the aerial spectrometric survey, a new step was made, because this method can be used for other topics than radioactive prospection such as geological survey and mining prospection for metallic and industrial minerals. The spectrometric method is based on the possibility to measure photopeak energies (gamma radiation) emitted by radioactive minerals and discriminate between them those emitted by U238, TI 208 and K40 respectively daughter products of uranium, thorium and potassium. For airborne survey, one consider that measuring instruments will allow to pick-up 80% of the radioactive emission concerning the first 15 to 30 centimetres of ground (1 metre maximum). The use of this method for geological and mineral exploration is based on the assumption that different rock types or ore bearing rock types are composed of certain amounts of rock forming minerals which comprise specific quantities of radioactive elements such as potassium, uranium and thorium (cf: Gabelman 77). To be able to evaluate the results of the spectrometric survey it will be necessary to know roughly the behaviour of the different radioactive elements through a complete geological cycle. (author)

FY 1998 report on the verification survey of geothermal survey technology, etc./Development of the reservoir fluctuation survey method (Summary). Theme 2. Development of the gravity survey method; 1998 nendo chinetsu tansa gijutsu nado kensho chosa choryuso hendo tansaho kaihatsu hokokusho (yoyaku). 2. Juryoku tansaho kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

As to the construction of a network system for gravity measurement, the continued observation of groundwater level was carried out as a 24-hour observation by setting water-level gauges at 10 wells. At one of the wells (No. 5), the 24-hour continued measurement was conducted for gravity as well as groundwater level. At the 9 wells except No. 5 well, the traveling measurement of gravity was made. In relation to the gravity measurement, the periodic measurement of three times a year was conducted at 138 measuring points. And at the same time, the elevation at measuring point was asked by a combination of GPS measuring and level measuring. Concerning the borehole gravity meter, the existing gravity calculation program was revised, and the model calculation of borehole gravity values was made. In the analysis/evaluation, as to the gravity fluctuation analysis, relations were studied between the groundwater level fluctuation and gravity fluctuation. Also conducted were study of effects of the unsaturated zone density fluctuation on gravity and selection of a measuring method of the soil water content saturation degree. In regard to the study of the precise gravity measuring method, the vertical gravity gradient was measured, and the correction method was studied. Further, the development was made of tidal models which are adaptable to the Yanaizu-Nishiyama area. (NEDO)

Gridded Data in the Arctic; Benefits and Perils of Publicly Available Grids

Science.gov (United States)

Coakley, B.; Forsberg, R.; Gabbert, R.; Beale, J.; Kenyon, S. C.

2015-12-01

Our understanding of the Arctic Ocean has been hugely advanced by release of gridded bathymetry and potential field anomaly grids. The Arctic Gravity Project grid achieves excellent, near-isotropic coverage of the earth north of 64˚N by combining land, satellite, airborne, submarine, surface ship and ice set-out measurements of gravity anomalies. Since the release of the V 2.0 grid in 2008, there has been extensive icebreaker activity across the Amerasia Basin due to mapping of the Arctic coastal nation's Extended Continental Shelves (ECS). While grid resolution has been steadily improving over time, addition of higher resolution and better navigated data highlights some distortions in the grid that may influence interpretation. In addition to the new ECS data sets, gravity anomaly data has been collected from other vessels; notably the Korean Icebreaker Araon, the Japanese icebreaker Mirai and the German icebreaker Polarstern. Also the GRAV-D project of the US National Geodetic Survey has flown airborne surveys over much of Alaska. These data will be Included in the new AGP grid, which will result in a much improved product when version 3.0 is released in 2015. To make use of these measurements, it is necessary to compile them into a continuous spatial representation. Compilation is complicated by differences in survey parameters, gravimeter sensitivity and reduction methods. Cross-over errors are the classic means to assess repeatability of track measurements. Prior to the introduction of near-universal GPS positioning, positional uncertainty was evaluated by cross-over analysis. GPS positions can be treated as more or less true, enabling evaluation of differences due to contrasting sensitivity, reference and reduction techniques. For the most part, cross-over errors for racks of gravity anomaly data collected since 2008 are less than 0.5 mGals, supporting the compilation of these data with only slight adjustments. Given the different platforms used for various

Subsurface geologic features of the 2011 central Virginia earthquakes revealed by airborne geophysics

Science.gov (United States)

Shah, Anjana K.; Horton, J. Wright; Burton, William C.; Spears, David B; Gilmer, Amy K

2014-01-01

Characterizing geologic features associated with major earthquakes provides insights into mechanisms contributing to fault slip and assists evaluation of seismic hazard. We use high-resolution airborne geophysical data combined with ground sample measurements to image subsurface geologic features associated with the 2011 moment magnitude (Mw) 5.8 central Virginia (USA) intraplate earthquake and its aftershocks. Geologic mapping and magnetic data analyses suggest that the earthquake occurred near a complex juncture of geologic contacts. These contacts also intersect a >60-km-long linear gravity gradient. Distal aftershocks occurred in tight, ~1-km-wide clusters near other obliquely oriented contacts that intersect gravity gradients, in contrast to more linearly distributed seismicity observed at other seismic zones. These data and corresponding models suggest that local density contrasts (manifested as gravity gradients) modified the nearby stress regime in a manner favoring failure. However, along those gradients seismic activity is localized near structural complexities, suggesting a significant contribution from variations in associated rock characteristics such as rheological weakness and/or rock permeability, which may be enhanced in those areas. Regional magnetic data show a broader bend in geologic structures within the Central Virginia seismic zone, suggesting that seismic activity may also be enhanced in other nearby areas with locally increased rheological weaknesses and/or rock permeability. In contrast, away from the Mw5.8 epicenter, geophysical lineaments are nearly continuous for tens of kilometers, especially toward the northeast. Continuity of associated geologic structures probably contributed to efficient propagation of seismic energy in that direction, consistent with moderate to high levels of damage from Louisa County to Washington, D.C., and neighboring communities.

2008 US Army Corps of Engineers (USACE) Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) Topobathy Lidar: North Carolina

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These files contain topographic lidar data collected by the Compact Hydrographic Airborne Rapid Total Survey (CHARTS) system along the coast of North Carolina near...

Geometric Liouville gravity

International Nuclear Information System (INIS)

La, H.

1992-01-01

A new geometric formulation of Liouville gravity based on the area preserving diffeo-morphism is given and a possible alternative to reinterpret Liouville gravity is suggested, namely, a scalar field coupled to two-dimensional gravity with a curvature constraint

Airborne gamma-ray spectrometer and magnetometer survey: Norton Bay Quadrangle (Alaska). Final report

International Nuclear Information System (INIS)

1980-01-01

During the months of July, August, and September 1979, an airborne high sensitivity gamma-ray spectrometer and magnetometer survey was conducted over ten 3 0 x 1 0 NTMS quadrangles of West-Central Alaska. The results obtained over the Norton Bay Map area are discussed. The final data are presented in four different forms: on magnetic tape; on microfiche; in graphic form as profiles and histograms; and in map form as anomaly maps and flight path maps. The histograms and the multiparameter are presented with the anomaly maps and flight path map in a separate volume. A total of twenty (20) uranium anomalies have been indicated on the interpretation map. No thorium anomalies were found. The uranium anomalies are all weak and generally have only U/K or U/T expression. Often the uranium concentration within the zone is low, and generally is less than 2.5 ppM. Only zones 9, with an average of 3.0 ppM eU, and 14, with 2.6 ppm have above average uranium content. Zone 14 is also the only uranium anomaly with combined U/K and U/T ratio anomalies. No single uranium anomaly is believed to represent an economic follow-up target. The most prospective area appears to be the elongate zone of generally high uranium content, formed by the deposits of the Shaktolik group, to the east of the Ungalik conglomerate. This zone flanks an elongate area of relatively strong shallow magnetic sources, interpreted to be related to a monozonitic intrusive of which the Christmas mountain forms part. This intrusive rock contains in other neighboring areas often high thorium and uranium concentrations and may here as well served as a possible source of uranium deposits

The internal layering of Pine Island Glacier, West Antarctica, from airborne radar-sounding data

DEFF Research Database (Denmark)

Karlsson, Nanna Bjørnholt; Rippin, David; Vaughan, David

2010-01-01

This paper presents an overview of internal layering across Pine Island Glacier, West Antarctica, as measured from airborne-radar data acquired during a survey conducted by the British Antarctic Survey and the University of Texas in the 2004/05 season. Internal layering is classified according...... to type (continuous/discontinuous/missing) and the results compared with InSAR velocities. Several areas exhibit disruption of internal layers that is most likely caused by large basal shear stresses. Signs of changes in flow were identified in a few inter-tributary areas, but overall the layering...

Airborne gamma spectrometric survey in the Chernobyl exclusion zone based on oktokopter UAV type

International Nuclear Information System (INIS)

Zabulonov, Yu.L.; Burtnyak, V.M.; Zolkin, I.O.

2015-01-01

The results of field studies of radioactive contamination condition of RWTSP ''Red Forest'' and ''Neftebaza'' in the Chernobyl zone, obtained by the authors in June 2015 are represented. The technique of detection of local inhomogeneities on the soil surface without contrasting borders by airborne gamma spectrometry from the board of oktokopter UAV type is worked through. The technique of searching and contouring of hidden burial of radioactive waste is practiced

Survey monitoring of environmental radioactivity in Gunsan area

Energy Technology Data Exchange (ETDEWEB)

Kim, Byoung Ho; Ro, Jeong Suk [Kunsan Regional Radioactivity Monitoring Station, Gunsan (Korea, Republic of)

2001-01-15

At Regional Radioactivity Monitoring Station in Kunsan have been measured priodically in 2000 gross beta activities in the airborne dust, fallout, precipitation and tap water and gamma exposure rates. Artificial radionuclide of {sup 137}Cs in airborne dust, fallout and precipitation have also been monitored at the station. As a part of environmental radiation/radioactivity distribution survey around Jeon-buk, vegetables, fishes, shellfishes, drinking water (total 33ea) samples were taken from sampling sites which were selected by KINS. We analysis gamma isotope for all. No significant Changes from the previous survey have been found in both beta activities and gamma exposure rates. As the results of analyzig an artificial nuclide concentration in living environmental sample in Jeon-buk are I fee of radiological contaminants.

Survey monitoring of environmental radioactivity in Gunsan area

Energy Technology Data Exchange (ETDEWEB)

Kim, Byoung Ho; Ro, Jeong Suk [Kunsan Regional Radioactivity Monitoring Station, Gunsan (Korea, Republic of)

2002-12-15

At Regional Radioactivity Monitoring Station in Kunsan have been measured priodically in 2002 gross beta activities in the airborne dust, fallout, precipitation and tap water and gamma exposure rates. Artificial radionuclide of {sup 137}Cs in airborne dust, fallout and precipitation have also been monitored at the station. As a part of environmental radiation/radioactivity distribution survey around Jeon-buk, vegetables, fishes, shellfishes, drinking water (total 33ea) samples were taken from sampling sites which were selected by KINS. We analysis gamma isotope for all. No significant changes from the previous survey have been found in both beta activities and gamma exposure rates. As the results of analyzig an artificial nuclide concentration in living environmental sample in Jeon-buk are fee of radiological contaminants.

Survey monitoring of environmental radioactivity in Gunsan area

International Nuclear Information System (INIS)

Kim, Byoung Ho; Ro, Jeong Suk

2002-12-01

At Regional Radioactivity Monitoring Station in Kunsan have been measured priodically in 2002 gross beta activities in the airborne dust, fallout, precipitation and tap water and gamma exposure rates. Artificial radionuclide of 137 Cs in airborne dust, fallout and precipitation have also been monitored at the station. As a part of environmental radiation/radioactivity distribution survey around Jeon-buk, vegetables, fishes, shellfishes, drinking water (total 33ea) samples were taken from sampling sites which were selected by KINS. We analysis gamma isotope for all. No significant changes from the previous survey have been found in both beta activities and gamma exposure rates. As the results of analyzig an artificial nuclide concentration in living environmental sample in Jeon-buk are fee of radiological contaminants

Aerial radiometric and magnetic survey: Lander National Topographic Map, Wyoming

International Nuclear Information System (INIS)

1979-01-01

The results of analyses of the airborne gamma radiation and total magnetic field survey flown for the region identified as the Lander National Topographic Map NK12-6 are presented. The airborne data gathered are reduced by ground computer facilities to yield profile plots of the basic uranium, thorium and potassium equivalent gamma radiation intensities, ratios of these intensities, aircraft altitude above the earth's surface, total gamma ray and earth's magnetic field intensity, correlated as a function of geologic units. The distribution of data within each geologic unit, for all surveyed map lines and tie lines, has been calculated and is included. Two sets of profiled data for each line are included, with one set displaying the above-cited data. The second set includes only flight line magnetic field, temperature, pressure, altitude data plus magnetic field data as measured at a base station. A general description of the area, including descriptions of the various geologic units and the corresponding airborne data, is included also

Looking inside the Panarea Island (Aeolian Archipelago, Italy by gravity and magnetic data

Directory of Open Access Journals (Sweden)

F. Greco

2008-06-01

Full Text Available In this paper we show and discuss the results of gravity and magnetic surveys of Panarea Island and its archipelago. The most recent volcanic manifestation occurred in November 2002 with a shallow submarine gas eruption between the islets of Dattilo, Panarelli, Lisca Bianca, Bottaro and Lisca Nera. Currently, the activity of Panarea is monitored through a multidisciplinary study under the umbrella of the Italian Department of Civil Protection with the goal of defining the hazard of this area. With this aim, in May 2006 the first gravity and magnetic surveys of Panarea Island and its archipelago were performed. The offshore magnetic data were obtained using a marine magnetometer, a Geometrics G880, from the Istituto Idrografico dell Marina (IIM. Onshore and offshore magnetic data were integrated into an unique dataset for complete magnetic coverage of the study area. By using two micro-gravimeters (LaCoste & Romberg, gravity data were collected along tracks every 250 meters. The gravity dataset was processed using the standard method. A Bouguer reduction was applied to the free-air gravity dataset using a detailed digital elevation model of the island and the neighbouring sea after evaluation of the optimal Bouguer density to reduce the topographic effect. The result is a Bouguer anomaly map that shows lateral variations in density distribution and the relationships between the shallow volcanic/crustal features and tectonic lineaments. This evidence is also highlighted by the magnetic pattern, which suggests the importance of the youngest volcanic deposits with respect to the magnetic features of the island.

Challenges and Opportunities of Airborne Metagenomics

KAUST Repository

Behzad, H.

2015-05-06

Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles.

Diurnal variations of airborne fungal spores concentration in the town and rural area

Directory of Open Access Journals (Sweden)

Idalia Kasprzyk

2012-12-01

Full Text Available Airborne fungal spores were monitored in 2001-2002 in Rzeszów (town and its neighborhood. The aim of investigations was to ascertain if there were differences in diurnal variations of airborne fungal spores concentration between town and rural area. The sampling was carried out using volumetric method. Traps were located at the same heights - app. 12 m. Airborne spores were sampled continuously. Microscopical slides were prepared for each day. Analysis was carried out on one longitudinal band of 48 mm long divided into 24 segments corresponding following hours of day. The results were expressed as mean number of fungal spores per cubic meter per 24 hours. For this survey, five geni of allergenic fungi were selected: Alternaria, Botrytis, Cladosporium, Epicoccum, Ganoderma. The concentrations of their airborne spores were high or very high. It was calculated theoretical day, where the hourly count was the percentage mean of number of spores at that time every chosen day without rainfall from 2001 and 2001 years. The diurnal periodicity of Alternaria, Cladosporium, Epicoccum and Ganoderma showed one peak, while Botrytis two. Anamorphic spores peaked in the afternoon, while their minima occurred in the morning. The highest concentrations of Ganoderma basidiospores were at down or at night, but minima during the day. There were no clear differences in the peak values between two studied sites. The results indicate that maximum concentrations of all spores generally occurred a few hour earlier in the rural area than in the town. Probably, in the rural area airborne spores came from many local sources and their diurnal periodicity reflected rhythm of spore liberation. Towns are characterized by specific microclimate with higher temperature and wind blowing to the centre. In Rzeszów fungal spores could be transported outside and carried out by wind from distant sources. This study showed, among others, that habitat conditions are an important factors

Magnetotelluric data collected to characterize aquifers in the San Luis Basin, New Mexico

Science.gov (United States)

Ailes, Chad E.; Rodriguez, Brian D.

2015-01-01

The U.S. Geological Survey is conducting a series of multidisciplinary studies of the San Luis Basin as part of the Geologic Framework of Rio Grande Basins project. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, magnetotelluric surveys, and hydrologic and lithologic data are being used to better understand the aquifers in the San Luis Basin. This report describes one north-south and two east-west regional magnetotelluric sounding profiles, acquired in June of 2010 and July and August of 2011, across the San Luis Basin in northern New Mexico. No interpretation of the data is included.

Covariant w∞ gravity

NARCIS (Netherlands)

Bergshoeff, E.; Pope, C.N.; Stelle, K.S.

1990-01-01

We discuss the notion of higher-spin covariance in w∞ gravity. We show how a recently proposed covariant w∞ gravity action can be obtained from non-chiral w∞ gravity by making field redefinitions that introduce new gauge-field components with corresponding new gauge transformations.

An aerial radiological survey of Areas 16 and 30, Nevada Test Site: Date of survey: June 1983

International Nuclear Information System (INIS)

Bluitt, C.M.

1986-10-01

An aerial radiological survey of the Nevada Test Site (NTS) was conducted for the US Department of Energy (DOE). The survey period was from 1 June to 16 June 1983, during which airborne measurements were obtained over Areas 16 and 30. The data were used to generate exposure rate, cobalt-60, and cesium-137 spatial distribution maps. The aerial survey results are expressed as exposure rate, cesium-137, and cobalt-60 isopleth contours, superimposed on NTS maps. 12 refs., 16 figs

Applications of high resolution airborne magnetic and radiometric data in the Barberton Greenstone Belt of South Africa

International Nuclear Information System (INIS)

Moore, C.

1994-01-01

We investigated the data obtained from a geophysical survey of the Greenstone Belt in the Barberton mountain land in the Transvaal, South Africa. A geological map is derived from the airborne magnetic and radiometric survey which differs significantly from the published geological map, particularly in the eastern are of the survey. There is no evidence contained within the geological data to suggest that the Greenstone Belt extends to a depth greater that 3 kilometers. The major geological constituents of the Barberton mountain land displays distinctive and diagnostic radiometric signatures, enabling accurate lithologic discrimination. 63 refs

Analogue Gravity

Directory of Open Access Journals (Sweden)

Carlos Barceló

2011-05-01

Full Text Available Analogue gravity is a research programme which investigates analogues of general relativistic gravitational fields within other physical systems, typically but not exclusively condensed matter systems, with the aim of gaining new insights into their corresponding problems. Analogue models of (and for gravity have a long and distinguished history dating back to the earliest years of general relativity. In this review article we will discuss the history, aims, results, and future prospects for the various analogue models. We start the discussion by presenting a particularly simple example of an analogue model, before exploring the rich history and complex tapestry of models discussed in the literature. The last decade in particular has seen a remarkable and sustained development of analogue gravity ideas, leading to some hundreds of published articles, a workshop, two books, and this review article. Future prospects for the analogue gravity programme also look promising, both on the experimental front (where technology is rapidly advancing and on the theoretical front (where variants of analogue models can be used as a springboard for radical attacks on the problem of quantum gravity.

Quantum Gravity Phenomenology

OpenAIRE

Amelino-Camelia, Giovanni

2003-01-01

Comment: 9 pages, LaTex. These notes were prepared while working on an invited contribution to the November 2003 issue of Physics World, which focused on quantum gravity. They intend to give a non-technical introduction (accessible to readers from outside quantum gravity) to "Quantum Gravity Phenomenology"

Description of gravity cores from San Pablo Bay and Carquinez Strait, San Francisco Bay, California

Science.gov (United States)

Woodrow, Donald L.; John L. Chin,; Wong, Florence L.; Fregoso, Theresa A.; Jaffe, Bruce E.

2017-06-27

Seventy-two gravity cores were collected by the U.S. Geological Survey in 1990, 1991, and 2000 from San Pablo Bay and Carquinez Strait, California. The gravity cores collected within San Pablo Bay contain bioturbated laminated silts and sandy clays, whole and broken bivalve shells (mostly mussels), fossil tube structures, and fine-grained plant or wood fragments. Gravity cores from the channel wall of Carquinez Strait east of San Pablo Bay consist of sand and clay layers, whole and broken bivalve shells (less than in San Pablo Bay), trace fossil tubes, and minute fragments of plant material.

Automated borehole gravity meter system

International Nuclear Information System (INIS)

Lautzenhiser, Th.V.; Wirtz, J.D.

1984-01-01

An automated borehole gravity meter system for measuring gravity within a wellbore. The gravity meter includes leveling devices for leveling the borehole gravity meter, displacement devices for applying forces to a gravity sensing device within the gravity meter to bring the gravity sensing device to a predetermined or null position. Electronic sensing and control devices are provided for (i) activating the displacement devices, (ii) sensing the forces applied to the gravity sensing device, (iii) electronically converting the values of the forces into a representation of the gravity at the location in the wellbore, and (iv) outputting such representation. The system further includes electronic control devices with the capability of correcting the representation of gravity for tidal effects, as well as, calculating and outputting the formation bulk density and/or porosity

Monitoring of airborne bacteria and aerosols in different wards of hospitals - Particle counting usefulness in investigation of airborne bacteria.

Science.gov (United States)

Mirhoseini, Seyed Hamed; Nikaeen, Mahnaz; Khanahmd, Hossein; Hatamzadeh, Maryam; Hassanzadeh, Akbar

2015-01-01

The presence of airborne bacteria in hospital environments is of great concern because of their potential role as a source of hospital-acquired infections (HAI). The aim of this study was the determination and comparison of the concentration of airborne bacteria in different wards of four educational hospitals, and evaluation of whether particle counting could be predictive of airborne bacterial concentration in different wards of a hospital. The study was performed in an operating theatre (OT), intensive care unit (ICU), surgery ward (SW) and internal medicine (IM) ward of four educational hospitals in Isfahan, Iran. A total of 80 samples were analyzed for the presence of airborne bacteria and particle levels. The average level of bacteria ranged from 75-1194 CFU/m (3) . Mean particle levels were higher than class 100,000 cleanrooms in all wards. A significant correlation was observed between the numbers of 1-5 µm particles and levels of airborne bacteria in operating theatres and ICUs. The results showed that factors which may influence the airborne bacterial level in hospital environments should be properly managed to minimize the risk of HAIs especially in operating theaters. Microbial air contamination of hospital settings should be performed by the monitoring of airborne bacteria, but particle counting could be considered as a good operative method for the continuous monitoring of air quality in operating theaters and ICUs where higher risks of infection are suspected.

Gravity is Geometry.

Science.gov (United States)

MacKeown, P. K.

1984-01-01

Clarifies two concepts of gravity--those of a fictitious force and those of how space and time may have geometry. Reviews the position of Newton's theory of gravity in the context of special relativity and considers why gravity (as distinct from electromagnetics) lends itself to Einstein's revolutionary interpretation. (JN)

Gravity inversion code

International Nuclear Information System (INIS)

Burkhard, N.R.

1979-01-01

The gravity inversion code applies stabilized linear inverse theory to determine the topography of a subsurface density anomaly from Bouguer gravity data. The gravity inversion program consists of four source codes: SEARCH, TREND, INVERT, and AVERAGE. TREND and INVERT are used iteratively to converge on a solution. SEARCH forms the input gravity data files for Nevada Test Site data. AVERAGE performs a covariance analysis on the solution. This document describes the necessary input files and the proper operation of the code. 2 figures, 2 tables

Airborne Lidar Surface Topography (LIST) Simulator

Science.gov (United States)

Yu, Anthony W.; Krainak, Michael A.; Harding, David J.; Abshire, James B.; Sun, Xiaoli; Cavanaugh, John; Valett, Susan; Ramos-Izquierdo, Luis; Winkert, Tom; Plants, Michael;

Digital airborne camera introduction and technology

CERN Document Server

Sandau, Rainer

2014-01-01

The last decade has seen great innovations on the airborne camera. This book is the first ever written on the topic and describes all components of a digital airborne camera ranging from the object to be imaged to the mass memory device.

Precisión de la aproximación geoide y geoestadística: cómo encontrar un mapa contínuo de datos de gravedad absoluta

Directory of Open Access Journals (Sweden)

Hongzhi Song

2015-10-01

Full Text Available An accurate geoid model is needed for surveyors and engineers who require orthometric heights on a common datum, and environ- ment scientists who require elevations relative to present sea level. Airborne gravity data has been collected by the National Geodetic Survey (NGS under the Gravity for the Redefinition of the Amer- ican Vertical Datum (GRAV-D project and is available along the coasts of the Gulf of Mexico. For this study we obtained a set of abso- lute gravity data derived from full-field gravity at altitude/elevation. We used the data to derive free-air gravity anomalies to establish gravity on the geoid. For spatial interpolation we used the kriging method to estimate gravity on the geoid in any location and krig- ing of the difference between gravity on the ellipsoid of reference and the geoid. Various kriging methods were used for evaluation of errors calculated in this study. The mean precision of the predicted val- ues is around 1.23 cm, a very good result for coastal regions, which traditionally have sparse gravity data sets.

Gravity brake

Science.gov (United States)

Lujan, Richard E.

2001-01-01

A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

Analysis of selected gravity profiles on the Hanford Reservation, Richland, Washington

International Nuclear Information System (INIS)

Little, J.T.; Richard, B.H.

1977-07-01

Regional gravity surveys have been conducted on the Hanford Reservation in the past. This analysis is an attempt at detailed gravity profiling over selected areas of the reservation. Over 450 gravity readings were taken during the summer of 1976. The Bouguer anomaly values of these stations, along with facies cross sections, were used to construct two-dimensional models. The models depict the buried basalt bedrock surface and the overlying sedimentary cover of the areas selected for profiling. In the eastern section of the reservation, the interpretation of the data suggests that there are three major buried valleys cut into the bedrock. These channels are most likely a combination of structural downwarping and erosion of these downwarps by an ancestral Columbia River. Along the western boundary of the reservation there are two closed depressions which are believed to be the result of the sub-fluvial vortex effect of Kolk erosion. It was found that, although two-dimensional gravity models are useful in determining the buried bedrock surface, they are ineffectual in delineating sedimentary contacts

Detection of airborne Legionella while showering using liquid impingement and fluorescent in situ hybridization (FISH).

Science.gov (United States)

Deloge-Abarkan, Magali; Ha, Thi-Lan; Robine, Enric; Zmirou-Navier, Denis; Mathieu, Laurence

2007-01-01

Aerosols of water contaminated with Legionella bacteria constitute the only mode of exposure for humans. However, the prevention strategy against this pathogenic bacteria risk is managed through the survey of water contamination. No relationship linked the Legionella bacteria water concentration and their airborne abundance. Therefore, new approaches in the field of the metrological aspects of Legionella bioaerosols are required. This study was aimed at testing the main principles for bioaerosol collection (solid impaction, liquid impingement and filtration) and the in situ hybridization (FISH) method, both in laboratory and field assays, with the intention of applying such methodologies for airborne Legionella bacteria detection while showering. An aerosolization chamber was developed to generate controlled and reproducible L. pneumophila aerosols. This tool allowed the identification of the liquid impingement method as the most appropriate one for collecting airborne Legionella bacteria. The culturable fraction of airborne L. pneumophila recovered with the liquid impingement principle was 4 and 700 times higher compared to the impaction and filtration techniques, respectively. Moreover, the concentrations of airborne L. pneumophila in the impinger fluid were on average 7.0 x 10(5) FISH-cells m(-3) air with the fluorescent in situ hybridization (FISH) method versus 9.0 x 10(4) CFU m(-3) air with the culture method. These results, recorded under well-controlled conditions, were confirmed during the field experiments performed on aerosols generated by hot water showers in health institutions. This new approach may provide a more accurate characterization of aerobiocontamination by Legionella bacteria.

The Cause of Gravity

OpenAIRE

Byrne, Michael

1999-01-01

Einstein said that gravity is an acceleration like any other acceleration. But gravity causes relativistic effects at non-relativistic speeds; so gravity could have relativistic origins. And since the strong force is thought to cause most of mass, and mass is proportional to gravity; the strong force is therefore also proportional to gravity. The strong force could thus cause relativistic increases of mass through the creation of virtual gluons; along with a comparable contraction of space ar...

Synoptic channel morphodynamics with topo-bathymetric airborne lidar: promises, pitfalls and research needs

Science.gov (United States)

Lague, D.; Launeau, P.; Gouraud, E.

2017-12-01

Topo-bathymetric airborne lidar sensors using a green laser penetrating water and suitable for hydrography are now sold by major manufacturers. In the context of channel morphodynamics, repeat surveys could offer synoptic high resolution measurement of topo-bathymetric change, a key data that is currently missing. Yet, beyond the technological promise, what can we really achieve with these sensors in terms of depth penetration and bathymetric accuracy ? Can all rivers be surveyed ? How easy it is to process this new type of data to get the data needed by geomorphologists ? Here we report on the use of the Optech Titan dual wavelength (1064 nm & 532 nm) operated by the universities of Rennes and Nantes (France) and deployed over several rivers and lakes in France, including repeat surveys. We will illustrate cases where the topo-bathymetric survey is complete, reaching up to 6 m in rivers and offers unprecedented data for channel morphology analysis over tens of kilometres. We will also present challenging cases for which the technology will never work, or for which new algorithms to process full waveform are required. We will illustrate new developments for automated processing of large datasets, including the critical step of water surface detection and refraction correction. In suitable rivers, airborne topo-bathymetric surveys offer unprecedented synoptic 3D data at very high resolution (> 15 pts/m² in bathy) and precision (better than 10 cm for the bathy) down to 5-6 meters depth, with a perfectly continuous topography to bathymetry transition. This presentation will illustrate how this new type of data, when combined with 2D hydraulics modelling offers news insights into the spatial variations of friction in relation to channel bedforms, and the connectivity between rivers and floodplains.

Cutoff for extensions of massive gravity and bi-gravity

International Nuclear Information System (INIS)

Matas, Andrew

2016-01-01

Recently there has been interest in extending ghost-free massive gravity, bi-gravity, and multi-gravity by including non-standard kinetic terms and matter couplings. We first review recent proposals for this class of extensions, emphasizing how modifications of the kinetic and potential structure of the graviton and modifications of the coupling to matter are related. We then generalize existing no-go arguments in the metric language to the vielbein language in second-order form. We give an ADM argument to show that the most promising extensions to the kinetic term and matter coupling contain a Boulware–Deser ghost. However, as recently emphasized, we may still be able to view these extensions as effective field theories below some cutoff scale. To address this possibility, we show that there is a decoupling limit where a ghost appears for a wide class of matter couplings and kinetic terms. In particular, we show that there is a decoupling limit where the linear effective vielbein matter coupling contains a ghost. Using the insight we gain from this decoupling limit analysis, we place an upper bound on the cutoff for the linear effective vielbein coupling. This result can be generalized to new kinetic interactions in the vielbein language in second-order form. Combined with recent results, this provides a strong uniqueness argument on the form of ghost-free massive gravity, bi-gravity, and multi-gravity. (paper)