ICE-SHEET ALTIMETER PROCESSING SCHEME

The analysis of altimeter data over non-ocean surfaces is complicated by the effects of topography and the dielectric properties of the surface. The philosophy behind the processing (for the U.K.-Earth Observation Data Centre) of altimeter data over ice sheets and shelves is explained and a description of the function and performance of the algorithms used is provided. The methods available for waveform retracking and slope correction, which present the primary difference between ocean and land altimeter data analysis, are discussed in detail. Results from their operation with Seasat altimeter data and a simulated surface profile are provided to indicate their likely performance with ERS-1 data. The contents and structure of the ice sheet data product is described and its intended applications discussed. Future modifications and calibration/validation of the data are also considered.