SAR image compression based on wavelet packets and sub-band coding

Synthetic aperture radar (SAR) is an imaging technique, which provides high-resolution images. The high resolution in the range direction is achieved by using large bandwidth signals and that in the azimuth direction is achieved by synthesizing a large aperture antenna using platform motion. The unique data collection geometry of SAR system requires that huge amounts of raw data be processed before obtaining a viewable image. Therefore, performing some form of compression on SAR raw data provides an attractive option for SAR systems. In this paper, we present a transform coding approach for SAR raw data compression. Due to presence of large dynamic range of frequency content in SAR raw data we propose the usage of wavelet packet transform. Experimental results of the proposed method provide significant improvement in SNR results over standard block adaptive quantization (BAQ) and JPEG2000 techniques.