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  • A British Antarctic Survey Twin Otter and survey team acquired 8,300 line-km of aerogeophysics data during the Austral summer of 1998/99. Gravity and radio-echo data were acquired simultaneously with the magnetic data at a compromise constant barometric height of 2,200 m, which provides a terrain clearance of 100 m over the highest peaks. Two separate surveys were conducted; one at 5 km line spacing (tie lines at 20 km) over and stretching beyond the southern extent of the Forrestal range (main survey), and one at 2 km line spacing (tie lines at 8 km) covering the Dufek Massif (detailed survey). Ashtech Z12 dual frequency GPS receivers were used for survey navigation. Pseudorange data were supplied to a Picodas PNAV navigation interface computer, which was used to guide the pilot along the pre-planned survey lines. The actual flight path was recovered, using carrier-phase, continuous, kinematic GPS processing techniques. All pseudorange navigation data were recorded at 1 Hz on a Picodas PDAS 1000, PC-based data acquisition system. We present here the processed line aerogravity data collected using Lacoste and Romberg air-sea gravity meter S83. Data are provided as XYZ ASCII line data.

  • This data set contains aerogravity data collected during the WISE/ISODYN project. This collaborative UK/Italian project collected ~ 61000 line km of new aerogeophysical data during the 2005/2006 austral summer, over the previously poorly surveyed Wilkes subglacial basin, Dome C, George V Land and Northern Victoria Land. We present here the processed line aerogravity data collected using a LaCoste & Romberg air-sea gravity meter S83 mounted in the BAS aerogeophysically equipped Twin Otter aircraft. Data are provided as XYZ ASCII line data.

  • The survey collected a total of 11,500 km of data along 22 lines, spaced 12 km apart and oriented perpendicular to the strike of both the Bouguer anomaly field, as derived from land data (McGibbon and Smith, 1991), and the major sub-ice topographical features (Doake et al., 1983). The speed of the aircraft was set to produce a sample spacing of about 60 m and the data were collected at heights between 1600 and 2000 m above sea level. The gravity signal was recorded using a LaCoste and Romberg air/sea gravimeter, S-83, which has been kindly loaned to BAS by the Hydrographic Office of the Royal Navy. The meter was modified by the ZLS company for use in an aircraft. The equipment was deployed in a BAS De-Havilland Twin Otter aircraft. Differential, dual frequency, carrier phase, GPS measurements of the aircraft''s motion were made using Trimble and Ashtech geodetic receivers and antennas. Ice thickness data were obtained using a BAS-built, radio echo sounding system (Corr and Popple, 1994). Ice-bottom returns over most of the survey area were obtained at a sample spacing of approximately 28 m. GPS measurements were tied into base stations in International Terrain Reference Frame network (Dietrich et al., 1998) and gravity measurements to base stations in the IGSN71 net (Jones and Ferris, 1999). We present here the processed line aerogravity data collected using Lacoste and Romberg air-sea gravity meter S83. Data are provided as XYZ ASCII line data.

  • An airborne radar survey was flown as part of the GRADES-IMAGE project funded by BAS over the Evans Ice stream/Carson Inlet region mainly to image englacial layers and bedrock topography during the 2006/07 field season. Aeromagnetic data were also opportunistically collected. We present here the processed line aeromagnetic data collected using scintrex cesium magnetometers mounted on the BAS aerogeophysical equipped Twin Otter. Data are provided as XYZ ASCII line data.

  • Over 20,000 km of new aeromagnetic data were acquired over Palmer Land during the 2002-2003 Antarctic campaign. Profile lines were oriented E-W with N-S tie lines. Line spacing was 5 km, tie lines were 25 km apart and nominal flight altitude was 2800 m. Aeromagnetic processing included magnetic compensation, IGRF removal, diurnal correction, and levelling. Mean cross-over errors after microlevelling were <1 nT. Aeromagnetic data were gridded (1 km cell size) and reduced to the pole. We present here the processed line aeromagnetic data acquired using scintrex cesium magnetometers mounted on the BAS aerogeophysical equiped Twin Otter. Data are provided as XYZ ASCII line data.

  • Airborne gravity data were collected using a Zero Length Spring Corporation (ZLS)-modified LaCoste and Romberg model S air-sea gravimeter. The meter was mounted in a gyro-stabilised, shock mounted platform at the centre of mass of the aircraft to minimise the effect of vibrations and rotational motions. GPS data were recorded with an Ashtech Z12 dual frequency receiver in the aircraft and at a fixed base station. Differential, carrier phase, kinematic GPS methods were then used to calculate all the navigational information used for the dynamic corrections of the aerogravity data. Standard processing steps were taken to convert the raw gravity data to free air anomalies, including latitude, free air and Eotvos corrections. The vertical accelerations of the aircraft, which dominate the gravity signal recorded by the meter, were calculated by double differencing GPS height measurements. In addition, a correction was made for gravimeter reading errors caused by the platform tilting when it was subjected to horizontal accelerations (Swain, 1996). After making the above corrections, the data were low pass filtered for wavelengths less than 9 km to remove short wavelength noise from the geological signal. The data were continued to a common altitude of 2050 m and levelled. Cross-over analysis at 118 intersections yielded a standard deviation of 2.9 mGal, which is within the 1-5 mGal error range typically reported for airborne gravity surveys after levelling. Comparison between airborne measurements and previous land-based gravity data (Garrett, 1990), yielded an RMS difference of ~4.5 mGal, which is within the 2 sigma range for airborne gravity data accuracy.

  • An airborne radar survey was flown during the austral summer of 2015/16 over the Foundation Ice Stream, Bungenstock Ice Rise, and the Filchner ice shelf as part of the 5-year 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 2015/16 aerogeophysics survey acquired ~7,000 line km of aerogeophysical data with a particular focus on the Foundation Ice Stream. Our Twin Otter aircraft was equipped with dual-frequency carrier-phase GPS for navigation, radar altimeter for surface mapping, wing-tip magnetometers, and a new ice-sounding radar system (PASIN-2). We present here the processed line aeromagnetic data collected using the Scintrex cs3 caesium magnetometer mounted in the BAS aerogeophysically equipped Twin Otter aircraft. Data are provided as XYZ ASCII line data.

  • In 2011, aerogeophysics data were acquired over Pine Island Glacier, West Antarctica on a grid comprising 30 transverse lines across the glacier, each around 20 km long, and with a spacing of roughly 500 m between the lines. The orientation of the lines was selected to be perpendicular to the surface features visible in satellite images in the central part of the ice shelf. Elevation of the ice-surface directly beneath the aircraft was simultaneously measured using a nadir-pointing laser altimeter. We present here the processed line aeromagnetic data acquired using scintrex cesium magnetometers mounted on the BAS aerogeophysical equiped Twin Otter. Data are provided as XYZ ASCII line data.

  • A British Antarctic Survey Twin Otter and survey team acquired 8,300 line-km of magnetic data during the Austral summer of 1998/99. Gravity and radio-echo data were acquired simultaneously with the magnetic data at a compromise constant barometric height of 2,200 m, which provides a terrain clearance of 100 m over the highest peaks. Two separate surveys were conducted; one at 5 km line spacing (tie lines at 20 km) over and stretching beyond the southern extent of the Forrestal range (main survey), and one at 2 km line spacing (tie lines at 8 km) covering the Dufek Massif (detailed survey). Wing-tip-mounted cesium vapour magnetometers acquired data at 10 Hz, which was resampled to 1 Hz after deletion of data corrupted by the radio echo transmissions. It is not possible to compensate the magnetic data for maneuver noise after this process as the data are under-;sampled with respect to maneuver noise. However, because gravity data was being acquired at the same time, turbulent conditions were avoided and so maneuver noise was at a minimum. Ashtech Z12 dual frequency GPS receivers were used for survey navigation. Pseudorange data were supplied to a Picodas PNAV navigation interface computer, which was used to guide the pilot along the pre-planned survey lines. The actual flight path was recovered, using carrier-phase, continuous, kinematic GPS processing techniques. All magnetic and pseudorange navigation data were recorded at 1 Hz on a Picodas PDAS 1000, PC-based data acquisition system. Data were de-spiked and then smoothed (~100 m low pass filter), before re-sampling from 10 to 1 Hz. The data were IGRF corrected, leveled and reduced to the pole in the field. A 2.5 km cell grid was produced. The negative bias to the anomaly amplitudes is a result of the poorly defined IGRF in this area. We present here the processed line aeromagnetic data acquired using scintrex cesium magnetometers mounted on the BAS aerogeophysical equiped Twin Otter. Data are provided as XYZ ASCII line data.

  • In 1998, aeromagnetic data over the Larsen Ice Shelf were acquired giving information about the geological structure beneath the ice shelf. We present here the processed line aeromagnetic data collected using scintrex cesium magnetometers mounted on the BAS aerogeophysical equipped Twin Otter. Data are provided as XYZ ASCII line data.