Comparison of two near-field imaging algorithms for synthetic aperture radar

Tomographic method is a common near-field imaging algorithm for synthetic aperture radar (SAR). However it is too slow for real time imaging when the span of the angle is large in azimuth. In order to alleviate the computational load, the algorithm based on the azimuth convolution has been proposed. This paper compares two different near-field imaging algorithms: the tomography-based method and the fast cyclical convolution algorithm based on linear interpolation and FFT. Through numerical simulations and experimental results, we show that the fast cyclical convolution algorithm based on linear interpolation and FFT is faster than the near-field tomographic method.