Читать книгу Inverse Synthetic Aperture Radar Imaging With MATLAB Algorithms - Caner Ozdemir - Страница 40

FFT is the efficient and fast way of evaluating the DFT of a signal. Normally, computing the DFT is in the order of N² arithmetic operations. On the other hand, fast algorithms like Cooley‐Tukey's FFT technique produce arithmetic operations in the order of N log(N) (Cooley and Tukey 1965; Brenner and Rader 1976; Duhamel 1990). An example of DFT is given is Figure 1.11 where a discrete time‐domain ramp signal is plotted in Figure 1.11a and its frequency‐domain signal obtained by an FFT algorithm is given in Figure 1.11b.