VALIDATION OF CRYOSAT-2 SARIN PERFORMANCE OVER ARCTIC SEA ICE

摘要

The main objective of this work is to validate CryoSat-2 (CS2) SARIn performance over sea ice by use of airborne laser altimetry data obtained during the CryoVEx 2012 campaign. A study by [1] has shown that the extra information from the CS2 SARIn mode increases the number of valid sea surface height estimates which are usually discarded in the SAR mode due to snagging of the radar signal. As the number of valid detected leads increases, the uncertainty of the freeboard heights decreases. In this study, the snow freeboard heights estimated using data from the airborne laser scanner are used to validate the sea ice freeboard obtained by processing CS2 SARIn level 1b waveforms. The possible reduction in the random freeboard uncertainty is investigated comparing two scenarios, i.e. a SAR-like and a SARIn acquisition. It is observed that using the extra phase information, CS2 is able to detect leads up to 2370 m off-nadir. A reduction in the the total random freeboard uncertainty of ～40% is observed by taking advantage of the CS2 interferometric capabilities, which enable to include ～35% of the waveforms discarded in the SAR-like scenario.