TABLE OF CONTENTS At this point in the book, two high-precision SAR processing algorithms have been presented, the range Doppler algorithm (RDA) and the chirp scaling algorithm (CSA). A comparable algorithm, the omega-K algorithm ( ?KA) is described in this chapter. In order to set the stage for the ?KA, some relevant properties of the RDA and the CSA are given here.
RDA: The range Doppler algorithm, presented in Chapter 6, was the first digital processing algorithm developed for satellite SAR data. It is still the most widely used algorithm because of its favorable tradeoff between efficiency, accuracy, maturity, and ease of implementation. One of the key features of the RDA is how an interpolator is used in the range Doppler domain to implement RCMC efficiently and accurately, in the face of the range variations of range migration and Doppler centroid.
The range-azimuth coupling in the received data is a function of azimuth frequency, and range time, with the azimuth frequency having a strong dependence and range time a weak one. The SRC is usually applied in the range frequency and azimuth time domain [see Figure 6.1(c)] in which the two dependencies are ignored. Even in the more accurate form of the RDA, in which SRC is implemented in the two-dimensional frequency domain, the range time dependence is not compensated [see Figure 6.1(b)]. This means that the range-azimuth coupling is not accurately compensated when the azimuth beamwidth is wide.
CSA: The chirp scaling algorithm, presented in Chapter...
