Compression of raw SAR data using entropy-constrained quantization

For the compression of raw SAR (synthetic aperture radar) data on-board spacecraft, the block adaptive quantization (BAQ) algorithm is often used due to its effectiveness and low implementation complexity. However, the entropy-constrained block adaptive quantization (ECBAQ) algorithm outperforms BAQ with respect to signal-to-quantization-noise-ratio and equals the performance of more complicated methods such as vector quantization and trellis coding variants. ECBAQ can be implemented using an architecture that is essentially not more complicated than that of a BAQ encoder and suitable for high-speed implementations. Moreover, the method features bit rate programmability with non-integer rates. This allows the SAR information throughput to be optimized for different types of applications.