Abstract:
A Lambert Glacier - Amery Ice Shelf series of airborne (Squirrel helicopter and Twin Otter fixed wing) RES profiles were conducted over two summer seasons; 1988/89 and 1989/90. The ANARE Mk V 100 MHz digital ice radar recorded ice thicknesses continuously along nearly 10,000 km of various flight paths 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
Quality
Gaps in the data (approximately 20% dropout) arose from loss of signal return in areas of extremely deep ice and/or internal reflections from complex structures within the ice. 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 35 mm BandW film, later scaled by hand every 20 s of flight time (approximately 1 km). Delay times were reduced to ice thicknesses assuming a signal propagation speed of 169 m/microsecond with no firn correction. The data have been checked internally by repeat measurement (crossover) along several intersecting flight paths. 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.
Access Constraints
Raw data were recorded on 35 mm BandW film and has been scaled into spreadsheet format (MS Excel) approximately every 1 km along track. Spreadsheet (MS Excel) geocoded files.
