COMPARISON OF IN SITU AND AIRBORNE MEASUREMENTS OF MULTI-YEAR SEA ICE THICKNESS WITH DUAL-FREQUENCY, POLARIMETRIC SAR OBSERVATIONS

First results are presented from a comparison of in situ and airborne measurements of sea ice thickness to C- and X-band polarimetric synthetic aperture radar images acquired over the Lincoln Sea in March-May 2012. Operation IceBridge data indicate a moderate correlation between ice surface roughness and thickness in this multi-year ice regime, motivating efforts to derive ice thickness from SAR data. C- band backscatter shows moderate correlations to in situ and airborne ice thicknesses (r approximate to 0.6). At X-band correlations with airborne ice thickness data are much lower. For all polarizations the relationship with ice thickness levels off at thicknesses greater than 5 m, where ice is heavily deformed. Current research efforts are focused on exploiting polarimetric parameters to discriminate thick deformed ice to support future efforts to develop a thickness retrieval algorithm for undeformed ice up to 5 m thick.