Abstract:

Based on the novel system with multiple-input multiple-output synthetic aperture radar (MIMO-SAR), an approach combining displaced phase center antenna (DPCA) with discrete chirp-Fourier transform (DCFT) is proposed for the detection, positioning and imaging of moving targets. The DCFT method is applied to estimate the alongtrack velocities of moving targets. Considering the useful characteristic of a single maximum value in amplitude figure which is aroused when the DCFT is used to deal with the chirp signal, a fast arithmetic for searching their along-track velocities is presented. Since the positions after pulse compression are different under the condition that the identical Doppler centroid frenquecy lies in the different carrier frequencies, the ratio of the positions is used to resolve the times of ambiguities; thus the reposition can be achieved. In the process of resolving the ambiguities, the analysis of the choice of carrier frequencies is provided. Through extending the single-input multiple-output system to a dual-channel MIMO system, the detection of moving targets under the low signal-to-noise ratio is achieved; moreover, the motion parameters, position and imaging of moving targets can also be estimated.