Abstract:

Synthetic aperture radar (SAR) raw data compression can reduce onboard downlink data rate effectively. However, the compression induces distortions on polarimetric information of quad polarimetric SAR data. Three widely used raw data compression methods including 4 bit quantization, 8∶3 block adaptive quantization (BAQ) and 8∶4 BAQ are evaluated through simulated quad polarimetric data under different signal-to-clutter ratio (SCR) conditions. Simulation results show that the influence of the data compression on residual channel imbalance is small and can be ignored under a certain condition. Besides, the impact of the data compression on residual crosstalk shows up only on condition that the SCR is much higher than 40 dB, while in other circumstances it is submerged in the impact of the background clutter. These results provide valuable information for selecting the proper data compression method of quad polarimetric SAR systems.