A study of bit planes for the compression of raw synthetic aperture radar data

The compression of raw SAR data has been a topic of interest to researchers for many years. The goal of such compression is to transmit the highest fidelity data from the radar satellite within the downlink bandwidth constraints. The necessity of new compression techniques is further emphasized as advances in the design of radar technologies are close to surpassing the capabilities of current compression techniques. Developing only a theoretical compression technique is not a complete solution to the problem as the technique must be realizable in the hardware available for placement on the radar satellite. The implementation must not only be low in computational complexity, but must also be able to handle the ever increasing throughput demands of the radar. Bit-planes have been used successfully with several other compression techniques, and are extremely amenable to hardware due to their inherent parallelism. This paper shows that bit-plane segmentation and simple coding transformation of raw SAR data can reduce the entropy of a single plane by 59%.