SAR SIGNAL PROCESSING ALGORITHMS

In space borne SAR systems some form of data compression is required to reduce the bandwidth of the downlink channel. In the present paper we have represented the complex SAR raw data with magnitude-phase (MP) and then applied the devised algorithm. It is observed that the phase information of the compressed data is preserved to the great extent. The quality of the reconstructed data is compared in terms of the important performance evaluation parameters like signal to noise ratio (SNR), standard deviation of the phase (PSD), mean phase error (MPE) and the compression ratio (CR). The magnitude-phase algorithm (BMPQ) is compared with that of Block Adaptive Quantization (BAQ) algorithm. The evaluation procedure is carried out in two domains, raw data domain and image domain. Numerical experiments were carried out using ERS-2 satellite data supplied by European Space Agency (ESA) showing that magnitude-phase algorithm provides us with more Compression Ratio (CR) choices than BAQ and for certain CR, MP algorithm provides at least one choice whose performance is better than or equal to that of BAQ. These two algorithms neither affect spatial resolution nor generate geometric distortion. Both of them have only a little effect on radiometric resolution.