Fast algorithm for a near-field synthetic aperture radar processor

A radar image can be formed by coherently integrating the backscattered fields over the measured frequency band and cross-range scan. This coherent integration can be seen as a convolution of the measured data and a focusing function, which only depends on the geometry of the measurement. Thus, by applying fast Fourier transform (FFT) techniques and computing a product in the Fourier domain one can efficiently reconstruct the target image. On the other hand, in the particular case of indoor synthetic aperture radar (SAR) measurements with the same geometry, the focusing operator must be computed just once and may be reused when processing the different datasets, reducing drastically the computing time