Phase Information Reserved Polarimetric SAR Raw Data Compression

Polarimetric SAR (POLSAR) can offer more information than single-polarized SAR that has the capability to image in all weather and day-night conditions. The multi-polarization mode and wide swath requirements result in a huge amount of data, which may exceed the on-board storage and downlink bandwidth. Effective compression of POLSAR raw data is clearly one of the best solutions. This paper presents a compression method for POLSAR raw data with the relative phase between co-polarized and cross-polarized channel being reserved. In this method, the amplitude is quantized for Rayleigh distribution with the phase of HH and VV channel quantized for uniform distribution. In order to reserve relative phase information, the phase difference between co-polarized (HH and VV) and cross-polarized (HV and VH) channel is optimally quantized for triangular distribution. Results show that by quantizing the phase difference, the relative phase information between HH (VV) and HV (VH) channel can be well preserved.