Coherent interferometric imaging for synthetic aperture radar in the presence of noise

Abstract

This paper shows that the coherent interferometric imaging strategy originally proposed in the context of passive or active arrays of antennas can be implemented for synthetic aperture radar, in which a single antenna is used as an emitter and as a receiver at successive positions along a trajectory. The idea is to backpropagate the cross correlations of the recorded signals over selected frequency-spatial windows rather than the signals themselves. The theoretical analysis shows that the signal-to-noise ratio can be enhanced dramatically compared to the standard matched filter processing, without any loss of resolution. This holds true when the fluctuations of the recorded signals have a spatial correlation (along the antenna trajectory) that is larger than the distance between two successive positions of the antenna and smaller than the length of the antenna trajectory. As a result, a good compromise between resolution and deblurring can be achieved by an appropriate choice of the spatial window size.