32ac27a1-abe0-4f33-ba30-65a093511fb8 eng utf8 dataset dataset NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom polardatacentre@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact 2021-11-11 ISO 19115 Geographic Information - Metadata ISO 19115:2003(E) European Petroleum Survey Group (EPSG) Geodetic Parameter Registry 2008-11-12 publication European Petroleum Survey Group EPSGadministrator@iogp.org https://www.epsg-registry.org/ EPSG Geodetic Parameter Dataset The EPSG Geodetic Parameter Dataset is a structured dataset of Coordinate Reference Systems and Coordinate Transformations, accessible through this online registry. information publisher urn:ogc:def:crs:EPSG::3031 6.18.3 Processed line aerogravity data from the 2015/16 PolarGAP survey of the South Pole region 2021-11-11 creation 2021-11-11 revision 2021-11-11 publication 2021-11-11 released 1 https://doi.org/10.5285/32ac27a1-abe0-4f33-ba30-65a093511fb8 doi GB/NERC/BAS/PDC/01583 https://data.bas.ac.uk/ Please cite this item as: None A new version of this dataset exists. Please have a look at: Ferraccioli, F., Forsberg, R., Matsuoka, K., Olesen, A., Jordan, T., Corr, H., Robinson, C., Kohler, J., & Bodart, J. (2024). Processed airborne radio-echo sounding data from the POLARGAP survey covering the South Pole, and Foundation and Recovery Glaciers, East Antarctica (2015/2016) (Version 2.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/6be0a803-78d4-4ca9-be02-3838866763c3 The ESA PolarGap airborne gravity, lidar/radar and aeromagnetic survey was carried out in Antarctica in the field season 2015/16. The purpose of the 2015/16 ESA PolarGAP airborne survey of the South Pole region was to fill the gap in satellite gravity coverage, enabling construction of accurate global geoid models. Additional radar flights over the Recovery Lakes for the Norwegian Polar Institute (NPI) were carried out as part of the same survey, but included collection of airborne gravity. Gravity data were collected using two complimentary systems. The primary system was a ZLS-modified Lacoste and Romberg (LCR) gravimeter (S-83) which gives exceptionally low and predictable long term drift. The secondary system was high specification inertial navigation system (iMAR RQH-1003), provided by TU Darmstadt, capable of resolving gravity anomalies even under turbulent conditions, but more prone to instrument drift. Results from both systems were merged to give a unified best product. The aircraft used was the BAS aerogeophysicaly equipped twin otter VP-FBL. Data are available as an ASCII table (.csv). No credit. completed Jordan, Tom British Antarctic Survey Researcher author Robinson, Carl British Antarctic Survey Researcher author Matsuoka, Kenichi Norvegian Polar Institute Researcher author Olesen, Arne Technical University of Denmark Researcher author Forsberg, Rene Technical University of Denmark Researcher author Ferraccioli, Fausto British Antarctic Survey Researcher author NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact asNeeded completed EARTH SCIENCE > Solid Earth > Geodetics/Gravity > Gravity EARTH SCIENCE > Solid Earth > Geodetics/Gravity theme Global Change Master Directory (GCMD) Science Keywords 2026-01-27 publication 23 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) Greenbelt MD United States of America https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher Aerogeophysics Antarctica Gravity South Pole geophysics theme South Pole Antarctica Recovery Lakes Antarctica Thiel Mountains Antarctica place Geology theme GEMET - INSPIRE themes, version 1.0 2021-01-06 revision otherRestrictions no limitations to public access otherRestrictions no limitations license Open Government Licence v3.0 otherRestrictions This data is governed by the NERC Data Policy: https://www.ukri.org/who-we-are/nerc/our-policies-and-standards/nerc-data-policy/ otherRestrictions Further by downloading this data the user acknowledges that they agree with the NERC data policy (), and the following conditions: 1. To cite the data in any publication as follows: https://doi.org/10.5270/esa-8ffoo3e - PolarGap: "Filling the GOCE polar gap in Antarctica and ASIRAS flight around South Pole" 2. The user recognizes the limitations of data. Use of the data is at the users' own risk, and there is no warranty as to the quality or accuracy of any data, or the fitness of the data for your intended use. The data are not necessarily fully quality assured and cannot be expected to be free from measurement uncertainty, systematic biases, or errors of interpretation or analysis, and may include inaccuracies in error margins quoted with the data. doi doi crossReference url url crossReference doi doi crossReference textTable eng utf8 geoscientificInformation -180.0 180.0 -90.0 -80.4 2015-12-15 2016-01-20 It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk. NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information distributor bytes 1 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=32ac27a1-abe0-4f33-ba30-65a093511fb8 WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: The airborne gravity measurements from the LCR gravimeter S-83 were corrected for aircraft dynamic movement using precise point positioning (ppp) GPS solutions following the methodology of Olesen et al 2002. Gravity from the iMAR RQH sensor was processed using a Kalman filtering approach to provide independent gravity estimates (Becker et al 2015). These independent estimates of the gravity field were combined using a Technical University of Denmark (DTU) in-house draping approach. This ensures that the long-wavelength, bias-stable LCR data are optimally merged with the more linear, but drifting, results of the iMAR RQH sensor. The processing parameters for the LCR gravity data included a 130-150 sec 2nd order Butterworth along-track filtering, corresponding to a spacing on the ground of ca. 6 km. The flight elevations were generally low level (1200 ft AGL), but occasionally higher due to fog or low-level clouds; flight altitudes varied between 2.9 and 4.3 km. The overall accuracy of the airborne processing was 2.2 mGal r.m.s., as inferred from 129-xover points, not taking into account the difference in heights at the cross-over points. This is a highly satisfactory result, given the rough conditions (field camps and temperatures down to -30degC), and the fact that the BAS Twin-Otter did not have an autopilot, which is usually a requirement for high-quality, bias-free aerogravity. No cross-over adjustment was performed on the data, so the data level of every single line is determined only by the gravimeter "apron" values, i.e. the stationary readings before or after flights. The gravity ties used to define absolute gravity values constraining the survey level were done with LCR land gravimeters G-784 (BAS) and G-867 (DTU), linked to earlier surveys and reference stations at McMurdo and Rothera, and adjusted in a least-squares process. The aerogravity data set includes the following channels: Fiducial: line_no*10000+running no latitude_decimal_degrees: DD.DDDDD longitude_decimal_degrees: DDD.DDDDD ellipsoidal_height_m: Elevation referenced to WGS1984 ellipsoid (m) gravity_disturbance_mGal: Gravity variations corrected to the WGS1984 ellipsoid (mGal) gravity_anomaly_mGal: Free air gravity anomalies corrected to the GOCE R5 geoid (mGal) Data collection: Data was collected using the BAS aerogeophysicaly equipped twin otter VP-FBL. Two gravity systems were used: A ZLS-modified Lacoste and Romberg (LCR) gravimeter S-83 which is a stabilised platform type sensor, and a high grade inertial navigation unit, iMAR RQH-1003, provided by TU Darmstadt, which acted as a so-called strapdown gravity sensor. Data from both these instruments was merged to give an optimal final product. Data quality: The gravity anomalies showed crossover errors with 2.2 mGal r.m.s., as inferred from 129-intersections. No levelling or additional adjustment was carried out. Data resolution: The radial design of the survey makes defining a specific resolution problematic. Line spacing at the survey edges was 90 km, reducing towards South Pole. The along track resolution is 6 km half-width based on the imposed filtering. asNeeded completed