THE EFFECT OF PULSE PHASE ERRORS ON THE CHIRP SCALING SAR PROCESSING ALGORITHM

The chirp scaling (CS) SAR processing algorithm uses the linear FM pro perty of the transmitted pulses to provide accurate range cell migrati on correction, However, when the transmitted pulse is not linear FM, o r if the FM rate is not known exactly, processing errors due to chirp scaling will result, This paper presents the resulting processing erro r in the CS algorithm, given pulse phase-errors that exceed those expe cted in current SAR systems, The registration and phase error that res ult in chirp scaling are negligible for typical or stable pulse phase errors, or can be avoided if phase modulation coefficients are estimat ed from the replica. A fast Fourier transformed pulse replica is suffi cient to form the range matched filter in the CS algorithm, giving sli ghtly better range resolution than the range/Doppler (R/D) algorithm.