Polar Waveform Data Reference Set from Seasat Altimeter Sensor Data Record

The pulse limited footprint diameter was 1.2 km for calm seas; beam-limited footprint diameter was 22.2 km. The PDRS is sub-divided into four data types: i) Antarctic ice sheet data, ii) Antarctic sea ice data, iii) Greenland ice sheet data, and iv) Arctic sea ice data. The source of the PDRS data set was 36 tapes comprising the SDR waveform data for a 17-day repeat period.

The data points of interest fall in two distinct geographic regions: south of -50 and north of 59 latitudes. In the southern region, all data with the TOIL flag set to land were extracted as Antarctic ice sheet data. In the northern region, all data with the TOIL flag set to land within Greenland (longitudes -58 W and -20 W) were extracted as Greenland ice sheet data The remaining sets of sea ice data were extracted using an algorithm based on the peakiness of the waveform which was developed by the Remote Sensing Group at Mullard Space Science Laboratories, UK.

The tapes are written in 9-track, 6250-bpi format. The block format is that described in the Seast Telemetry dictionary, containing 23 waveforms packed into 2988 2-byte words. Each tape is divided into logical files separated by a file mark, one per source tape.

Full tape copies will be made of this data set on request. Tape handling costs will be charged.