Low-altitude Target Detection Technology Based On OFDM-MIMO Radar

The multipath propagation of signals was one of the main problems of radarlow-altitude target detection. In recent years, more and more cruise missiles and otherlow-altitude penetration weapons appeared on the battlefield, which posed seriouschallenges on radar detection. Due to the presences of clutter and multipath effects, itwas more difficult to detect low-altitude high-speed targets for radars. So thelow-altitude radar target detection problem was of great significance in strong clutterenvironment.Deal with these problems, employing Multiple-In put Multiple-Out-put(MIMO)radar technology and Orthogonal Frequency Division Multiplexing(OFDM) technologycan obtain both frequency diversity gain and spatial diversity gain, it was feasible tocombine these two techniques, so OFDM-MIMO radar was used in order tosimultaneously achieved the above two gain, thereby inhibited the effect of thefluctuations brought by multipath signals, and stabilized the low-altitude targetdetection performance. In this paper, around of this technology the following works hadbeen done:1. The geometric model of the spread of low-level target signal by ground-basedradar had been built, and the influences of multipath propagation of the signals to radardetection performance had been analyzed, including the echo amplitude, power, and theprobability of detection.2. The OFDM-MIMO radar system had been used to suppress multipath signalswith a dual-threshold detection method in order to further enhance the low-altitudetargets detection performance. The superiority of the dual-threshold detection ofOFDM-MIMO radar on the low altitude target detection performance was proved by thenumerical results.3. the waveform optimization method based on OFDM-MIMO radar had beenresearched. To improve the low altitude target detection performance, MIMO radarwaveform optimization method based on frequency diversity had been employed in thenoise and clutter environment of the known statistical properties. Combined Solution for optimal transmitted waveform and receiving filter to maximize thesignal-to-clutter-noise ratio had been researched.. In the end the simulation resultsverified the effectiveness of the algorithm.