Space-Range-Doppler Focus-Based Low-observable Moving Target Detection Using Frequency Diverse Array MIMO Radar

The radar echoes of moving targets in a clutter background are extremely weak and their characteristics are complex. A low-observable moving target detection technology has become a key constraint to radar performance, requiring the radar to provide flexible freedom and higher parameter estimation capabilities. In this paper, a frequency diverse array MIMO (FDA-MIMO) radar is used for moving target detection in a clutter background, which combines the information in spatial (azimuth)range-frequency (Doppler) domains. Based on the signal model of the FDA-MIMO radar, a novel signal processing method is proposed named as space-range-Doppler focus (SRDF) processing. Theoretical and simulations analysis shows that this method can be regarded as the combination of multiple cascaded signal processing, such as beamforming, pulse compression, and Doppler filtering of a conventional array radar. It can distinguish clutter and moving targets in multidimensional space, improve signal-to-clutter ratio, and achieve high-precision measurement of target motion parameters via sparse time-frequency distributions. It will provide a new approach for moving target detection and classification in complex backgrounds.