Low-altitude target detection method based on multi-frequency point echo amplitude reversed order statistics

Abstract

The invention discloses a low-altitude target detection method based on multi-frequency point echo amplitude reversed order statistics. The low-altitude target detection method based on the multi-frequency point echo amplitude reversed order statistics mainly solves the problem that low-altitude target detection performance in the prior art is poor in multi-path environment. The low-altitude target detection method includes: 1) performing matched filtering and linear detection on multi-frequency point echo signals received by a radar, and outputting signal envelope; 2) selecting detection units and reference units from the signal envelope; 3) performing reversed order arrangement on the detection units to obtain a group of reversed order data; 4) evaluating reflection coefficient, and calculating an optimal K value; 5) utilizing the optimal K value and the reversed order data to calculate detection amount of the echo signals; 6) utilizing reference unit data to evaluate clutter amplitude through a unit average method; 7) calculating a detection threshold coefficient; 8) utilizing the clutter amplitude and the threshold coefficient to obtain a detection threshold of the echo signals; and 9) comparing the detection value to the detection threshold, and judging whether a target exist. The low-altitude target detection method based on the multi-frequency point echo amplitude reversed order statistics is high in detection performance at low signal-to-clutter ratio and improves radar detection capacity of the low-altitude target.

Description

technical field [0001] The invention belongs to the technical field of radar, and relates to a multi-frequency point non-coherent accumulation signal detection method, which can be used for signal detection of broadband radar in a multi-path environment. Background technique [0002] Low-altitude and ultra-low-altitude targets are difficult to detect and are one of the four major threats to radar. Its main difficulties include: strong ground-sea clutter and difficult multipath problems. To detect small flying targets in strong clutter, the radar beam must have enough energy to point to the ground, so the ground sea reflects strong clutter. At the same time, in addition to the direct wave signal of the target, the radar will also receive the reflected echo signal generated by the ground and sea surface, thus forming a multipath effect. This effect causes the amplitude and phase of the received signal of the radar to change. Spikes often appear in the echo, which increases t...

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Problems solved by technology

The research shows that the M / N detection method has poor detection performance in the case of low signal-to-clutter ratio, especially in the complex ground-sea clutter environment. It is difficult for the signal-to-clutter ratio echo to exceed the detection threshold, which will cause the target to miss the alarm. At the same time, two-level threshold detection is required. The first-level detection requires N times of detection, and the second-level detection requires one detection. Big

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