A Lambert Glacier - Amery Ice Shelf series of airborne (Squirrel helicopter and Twin Otter fixed wing) RES and surface elevation profiles were conducted over two summer seasons; 1988/89 and 1989/90. Altogether nearly 10,000 km of various flight paths were undertaken, operating out of Mawson (67.60 S, 62.88 E), Davis (68.58 S, 77.97 E), Dovers (70.22 S, 65.87 E) or Beaver Lake (70.80 S, 68.18 E).
More information can be found at the BEDMAP website.
The fields in this dataset are:
Mission ID Latitude Longitude Ice Thickness Surface Elevation Water Column Thickness Bed Elevation
Gaps in the data exceeded 50% for 1988/89 (lack of digital barometer), but formed a largely complete set for 1989/90. The ANARE Mk V 100 MHz ice radar produced peak power of 4 kW with a pulse duration of 250 ns and repetition rate of 10 kHz. A logarithmic amplifier stage was incorporated into the system. Fixed wing (Twin Otter) antenna array consisted of a transmit and receive yagi (1 driven ... element, 1 director, aircraft wing as reflector); helicopter (AS350B Squirrel) antenna array consisted of a single-element in a pseudo-corner corner reflector arrangement beneath the aircraft body. Typical flight speeds were 240 km/hr (Twin Otter) and 180 km/hr (Squirrel). Typical flight altitudes were 300 m above the terrain surface for both aircraft. Data was recorded continuously on 35mm BandW film, later scaled by hand every 20 s of flight time (approximately 1 km). Delay times were reduced to aircraft-surface separations assuming a signal propagation speed of 300 m/microsecond. For 1988/89 no aircraft barometer was available. Any elevation data for this season was based on interpolation between surface points of known elevation (from surface differential GPS survey) assuming constant rate of change of aircraft elevation (approx. 5200 km of lfight path). For 1989/90 season a digital barometer was logged every 20 s on board the aircraft and elevations were produced using aircraft-surface separations from the ice radar record (approx. 4100 km of flight path). The data have been checked by comparison (crossover) to other available datasets for the region. Pseudo-range GPS (without selective availability; SA) available for part of the 1988/89 (limited GPS constellation) and all the 1989/90 data sets; accurate to 30-100 m, digitally logged every 20 s. Dead-reckoning elsewhere; with reference to visual landmarks or features recognisable on Landsat imagery; accurate to within several kilometres.
An entry of -9999 in the spreadsheet indicates null data.
BandW 35 mm film for RES aircraft-surface separation data. Digital barometer for aircraft elevation data. Data stored on a spreadsheet (MS Excel) geocoded files.