Reduction of artifacts resulting from using coarse quantized correlators in SAR imaging

Synthetic aperture radar (SAR) is a two dimensional imaging system that processes reflected radar signals into an image of the reflecting object without recourse to large antennas. Excessively high data rates are encountered in SAR processing due to the fact that contributions to a single image point are from several echoes. This results in computational loads beyond the capability of existing processors. Quantization techniques are used to reduce the data rates. However, this results in undesirable side effects in the form of artifacts appearing the correlated outputs. We discuss the effect of quantization on the correlator outputs and we propose two simple methods which reduce artifacts considerably. One approach is based on the addition of a complex sine wave to the received signal and the other is based on wavelet decomposition.