SAR derived sea ice thickness during ICEX´92

Downward looking synthetic aperture radar (SAR) imagery and upward looking sonar draft data collected during the ICEX´92 experiment in the Lincoln Sea are used to develop an algorithm for converting SAR backscatter values directly to sea ice thickness via a transfer function. This algorithm uses statistical correlations of registered P-3 Aircraft SAR data and sonar draft scans to derive the backscatter/thickness relationship. First the data sets are registered using recorded position information. Next, a cross-correlation is performed to fine-tune the registration. The transfer function between the SAR backscatter and sonar draft is then derived using the cumulative distribution functions of the data sets. The benefit of this statistical approach is a reduction in the need for precise registration of the data sets. The derived relationship is applied to a full two-dimensional SAR image to generate a sea ice thickness map