0cb61583-3985-4875-b141-5743e68abe35 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 2021-10-12 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 airborne radio-echo sounding data from the FISS 2016 surveys covering the Filchner and Halley Ice Shelves, and the English Coast (western Palmer Land), West Antarctica (2016/2017) 2021-10-12 creation 2021-10-12 revision 2021-10-12 publication 2021-10-12 released 1.0 https://doi.org/10.5285/0cb61583-3985-4875-b141-5743e68abe35 doi GB/NERC/BAS/PDC/01571 https://data.bas.ac.uk/ NE/L013770/1 award Please cite this item as: Corr, H., Robinson, C., Jordan, T., Nicholls, K., & Brisbourne, A. (2021). Processed airborne radio-echo sounding data from the FISS 2016 surveys covering the Filchner and Halley Ice Shelves, and the English Coast (western Palmer Land), West Antarctica (2016/2017) (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/0cb61583-3985-4875-b141-5743e68abe35 A new version of this dataset exists. Please have a look at: Corr, H., Robinson, C., Jordan, T., Nicholls, K., Brisbourne, A., & Bodart, J. (2024). Processed airborne radio-echo sounding data from the FISS 2016 surveys covering the Filchner and Halley Ice Shelves, and the English Coast (western Palmer Land), West Antarctica (2016/2017) (Version 2.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/e203926b-7a54-4c33-a5df-04df2293d7d3 Three separate airborne radar surveys were flown during the austral summer of 2016/17 over the Filchner Ice Shelf and Halley Ice Shelf (West Antarctica), and over the outlet glacier flows of the English Coast (western Palmer Land, Antarctic Peninsula) during the Filchner Ice Shelf System (FISS) project. This project was a NERC-funded (grant reference number: NE/L013770/1) collaborative initiative between the British Antarctic Survey, the National Oceanography Centre, the Met Office Hadley Centre, University College London, the University of Exeter, Oxford University, and the Alfred Wenger Institute to investigate how the Filchner Ice Shelf might respond to a warmer world, and what the impact of sea-level rise could be by the middle of this century. The 2016/17 aerogeophysics surveys acquired a total of ~26,000 line km of aerogeophysical data. The FISS survey consisted of 17 survey flights totalling ~16,000 km of radar data over the Support Force, Recovery, Slessor, and Bailey ice streams of the Filchner Ice Shelf. The Halley Ice Shelf survey consisted of ~4,600 km spread over 5 flights and covering the area around the BAS Halley 6 station and the Brunt Ice Shelf. The English Coast survey consisted of ~5,000 km spread over 7 flights departing from the Sky Blu basecamp and linking several outlet glacier flows and the grounding line of the western Palmer Land, including the ENVISAT, CRYOSAT, GRACE, Landsat, Sentinel, ERS, Hall, Nikitin and Lidke ice streams. Our Twin Otter aircraft was equipped with dual-frequency carrier-phase GPS for navigation, radar altimeter for surface mapping, wing-tip magnetometers, an iMAR strapdown gravity system, and a new ice-sounding radar system (PASIN-2). We present here the full radar dataset consisting of the deep-sounding chirp and shallow-sounding pulse-acquired data in their processed form, as well as the navigational information of each trace, the surface and bed elevation picks, ice thickness, and calculated absolute surface and bed elevations. This dataset comes primarily in the form of NetCDF and georeferenced SEGY files. To interactively engage with this newly-published dataset, we also created segmented quicklook PDF files of the radar data. No credit. completed Corr, Hugh British Antarctic Survey Researcher author Robinson, Carl British Antarctic Survey Researcher author Jordan, Tom British Antarctic Survey Researcher author Nicholls, Keith British Antarctic Survey Researcher author Brisbourne, Alex 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 > Cryosphere > Glaciers/Ice Sheets > Glacier Elevation/Ice Sheet Elevation EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets > Glacier Thickness/Ice Sheet Thickness EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets > Glacier Topography/Ice Sheet Topography EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets EARTH SCIENCE > Spectral/Engineering > Radar 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 Antarctic aerogeophysics ice thickness radar surface elevation theme Filchner Ice Shelf Antarctica English Coast of western Palmer Land Antarctica Halley Ice Shelf Antarctica place Elevation 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: Corr, H., Robinson, C., Jordan, T., Nicholls, K., & Brisbourne, A. (2021). Processed airborne radio-echo sounding data from the FISS 2016 surveys covering the Filchner and Halley Ice Shelves, and the English Coast (western Palmer Land), West Antarctica (2016/2017) (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/0CB61583-3985-4875-B141-5743E68ABE35 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. otherRestrictions None doi doi crossReference doi doi crossReference url url largerWorkCitation url url crossReference doi doi crossReference textTable eng utf8 elevation geoscientificInformation -14.58 -67.5 -83.51 -79.58 2016-12-15 2017-01-22 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 application/x-hdf application/pdf application/octet-stream bytes 52076478464 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=0cb61583-3985-4875-b141-5743e68abe35 WWW:LINK-1.0-http--link Get Data Download data download bytes 52076478464 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=0cb61583-3985-4875-b141-5743e68abe35 WWW:LINK-1.0-http--link Get Data Download data download bytes 52076478464 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=0cb61583-3985-4875-b141-5743e68abe35 WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: ** Instrumentation and Processing: Radar data were collected using the new bistatic PASIN-2 radar echo sounding system mounted on the BAS Twin Otter aircraft "VP-FBL" and operating with a centre frequency of 150 MHz and using a 4-microseconds, 13 MHz bandwidth linear chirp. The three surveys all varied slightly in terms of radar configuration, with FISS being configured as a 12-element swath radar, Halley configured as three distinct antenna groups with different gains to cater for the awkward Brunt ice, and the English Coast configured as a polarimetric radar. More information on the antennae configuration can be found in the 'Data Collection' section further down this page. Note that flights F02-18 were flown as part of the FISS survey, flights F19-23 were flown over the Halley Ice Shelf, and flights F25-31 were flown over the English Coast (western Palmer Land). Chirp compression was applied using a Blackman window to minimise sidelobe levels, resulting in a processing gain of 10 dB. The chirp data was processed using a coherent averaging filter (commonly referred to as unfocused Synthetic Aperture Radar (SAR) processing) with Doppler beam sharpening to enhance the signal to clutter ratio of the bed echo and improve visualisation. The received chirp of 4 microseconds, 13 MHz bandwidth data was compressed, filtered, and decimated from the original trace acquisition rate of 125 Hz to 5Hz, equivalent to ~11m in along-track spacing. The chirp data is best suited to assess the bed and internals in deep ice conditions. The coherent pulse-data (0.1-microseconds) was processed using a coherent averaging filter. This data is best used to assess the internal structure and bed in shallow ice conditions. The bed reflector was first automatically depicted on the chirp data using a semi-automatic picker in the PROMAX software package. All the picks were afterwards checked and corrected by hand if necessary. The picked travel time was then converted to depth using a radar wave speed of 168 m/microseconds and a constant firn correction of 10 m. Where possible, the ice surface location within the radargrams was calculated using lidar measurements of surface elevation. In areas where lidar data was not available, the location of the surface reflection was picked directly from the radargram. The origin of the elevation measurement can be found in the 'surface_source_layerData' variable in this NetCDF, and is composed of either: 0 = LIDAR, 1 = interpolated LIDAR for gaps ~55 m, 2 = radar. Note: Flights F21-22 and F31 contain no bed/surface pick or elevation information (such as surface/bed elevation/aircraft elevations, ice thickness, etc). Flights F19-20 and F30 contain bed/surface pick but no elevation data. Note also that flight F31 only contain the shallow-sounding pulse data. ** Coordinates and Positions: The coordinates provided in the NetCDF for the surface and bed elevation for each radar trace are in longitude and latitude (WGS84, EPSG: 4326). The navigation attributes for the radar data in the NetCDF are in projected X and Y coordinates (Polar Stereographic, EPSG: 3031), as follows: Latitude of natural origin: -71 Longitude of natural origin: 0 Scale factor at natural origin: 0.994 False easting: 0 False northing: 2082760.109 The coordinates in the SEGY data are also in projected X and Y coordinates (Polar Stereographic, EPSG: 3031), although note that these are in integer format due to the SEGY limitations (see section below). Positions are calculated for the phase centre of the aircraft antenna. All positions (Longitude, Latitude and Height) are referred to the WGS1984 ellipsoid. Note: The PriNumber in both chirp and pulse SEGY differs, however the trace number and time of each trace is the same for both radar variables. We have therefore provided 2x NetCDF variables for the PriNumber in case this is nee...(80) Data collection: ** Instrument: Radar data were collected using the bistatic PASIN-2 (Polarimetric radar Airborne Science Instrument 2) radar echo sounding system mounted on the BAS Twin Otter aircraft "VP-FBL" and operating with a centre frequency of 150 MHz and using a pulse-coded waveform at an effective acquisition rate of 312.5 Hz and a bandwidth of 13 MHz. The Pulse Repetition Frequency was 15,625 Hz (pulse repetition interval: 64 microseconds). ** Antenna configuration: 8 transmitters (4x port side and 4x starboard side) 12 receivers (8x wings and 4x belly) Transmit power: 1 kW into each antennae Maximum transmit duty cycle: 10% at full power FISS: 12x channel swatch radar (8x transmit, 12x receive) Halley: Similar to FISS but with 30dB attenuation in the receive path for the starboard antennae to accommodate for varying ice conditions around the Brunt Ice Shelf. English Coast: Full polarimetric mode ** Waveform details FISS: Five waveforms, 4uS Tukey port, 4us Tukey starboard, 4uS Tukey (180deg out of phase) port, 4 uS Tukey (180deg out of phase) starboard, 1 uS Tukey antenna 1 (port). Halley: Five waveforms, 4uS Tukey port, 4uS Tukey starboard, 4 uS Tukey (180deg out of phase) port, 4 uS Tukey (180deg out of phase) starboard, 1 uS Tukey antenna 1 (port). Starboard 30dB attenuation on RX. English Coast: Five waveforms, 4uS Tukey port, 4uS Tukey starboard, 4 uS Tukey (180deg out of phase) port, 4 uS Tukey (180deg out of phase) starboard, 1 uS Tukey antenna 1 (port). Port antennas rotated. ** Radar receiver configuration: Receiver vertical sampling frequency: 22 MHz (resulting in sampling interval of 45.4546 ns) Receiver coherent stacking: 25 Receiver digital filtering: -50 dBc at Nyquist (11 MHz) Effective PRF: 125 Hz (post-hardware stacking) Sustained data rate: 10.56 Mbytes/second Data quality: - Average spacing between radar traces: 11 m - Line spacing: ~3.5-km (English Coast) - Radar centre frequency: 150 MHz - Radar bandwidth: 13 MHz - Radar Receiver vertical sampling frequency: 22 MHz - Absolute GPS positional accuracy: ~0.1 m (relative accuracy is one order of magnitude better). Banking angle was limited to 10 degrees during aircraft turns to avoid phase issues between GPS receiver and transmitter. Note: The SEGY and bed pick files for the English Coast section of the FISS 2016/17 surveys can also be found at: https://doi.org/10.5285/e07d62bf-d58c-4187-a019-59be998939cc. However note that the SEGY data found there is not georeferenced. The datasets found here have been considerably curated and improved, and thus can be considered the latest and full dataset. asNeeded completed