Research on Waveform Design and Imaging of MIMO-SAR

Abstract

MIMO SAR, a new type of SAR imaging system, is an effective way to solve the problem of HRWS (high-resolution and wide-swath). The core issue of MIMO SAR is the design of orthogonal waveforms. Microwaves with good-orthogonality, high-coherence, simple transmitting and large time-bandwidth product are beneficial for high-resolution imaging. Both the positive and negative frequency modulated signals and the short-term shift-orthogonal signals are suitable transmit signals for MIMO SAR. In this paper, based on the positive and negative frequency modulated signals and the short-term shift-orthogonal signals, we analyze the imaging performance of the two transmit signals by the correlation functions and imaging results of point targets. On this basis, through the ingenious combination of the positive and negative frequency modulated signals and the short-term shift-orthogonal signals, we design the four orthogonal transmit waveforms for MIMO SAR. The simulation of their correlation functions verifies the effectiveness of the four transmit waveform design.