introduction of azimuth fft architecture in range doppler imaging algorithm

an important section of range-doppler imaging algorithm in sar systems which needs large number of resources, memories and solution time, is fft on the azimuth dimension. in this paper, by decomposing the fft relation, and converting to smaller dimension ffts, implementation has been simplified. the proposed method, based on removing the extra phase factors reduces the resources, memories and solution time in hardware. evaluation of the proposed method show that optimum architecture depends on image resolution, next processing stage and the number of fft points. using the proposed architecture leads to implement the whole range-doppler imaging algorithm in smaller hardware.