Adaptation of stepped frequency continuous waveform to range-Doppler algorithm for SAR signal processing

In this paper, a novel and complete derivation of the range doppler algorithm (RDA) formulation is developed for stepped frequency continuous wave (SFCW) synthetic aperture radar (SAR) usage. As the RDA has been originally developed for linear frequency modulated (LFM) pulse excited SAR data, the detailed mathematical derivation of SFCW based RDA formulation is presented with similarities, differences and additions to the traditional LFM-RDA formulation for comparison. Then, the developed SFCW-RDA was tested with simulation data and the performance of the algorithm is determined by examining some important parameters including impulse response width, peak to sidelobe ratio, integrated side lobe ratio, range resolution, and azimuth resolution. The performance metrics of the SFCW-RDA in comparison to LFM-RDA thru the constructed SAR images have proven the implementation validity of the proposed technique.