Weak target detection method based on multispectral accumulation

Abstract

The invention discloses a weak target detection method based on multispectral accumulation. The problems that an operating distance is reduced when a weak target is detected and the operating distance can not be improved just by time accumulation in the prior art are mainly solved. The achievement processes are as foillows: 1) enabling an analogue signal to pass through a three-path analogue filter, filtering a target signal main spectral line and left and right spectral lines, and changing into three paths of continuous wave signals; 2) carrying out digital sampling on the three paths of continuous wave signals, calculating to obtain a digital weight value, and then carrying out coherent integration on the three paths of signals by digital weighting; 3) searching an acceleration value and compensating the data after coherent integration and carrying out spectral analysis to form a Doppler-acceleration two-dimensional plane; (4) carrying out constant false alarm detection on the Doppler-acceleration plane, and carrying out center gathering treatment on a point of passing through a threshold to obtain a target movement parameter. According to the weak target detection method, the detection distance of a radar seeker can be prolonged under the situation of not increasing the transmitting power and the aperture of the seeker.

Description

technical field [0001] The invention belongs to the technical field of radar, and in particular relates to a method for increasing the detection range of a weak target by using multispectral line accumulation, which can be used to increase the detection range of a weak target. Background technique [0002] With the development and maturity of various modern technologies, especially stealth technology, the radar cross-sectional area RCS of aircraft and missile targets has decreased by one to two orders of magnitude, which greatly affects the detection capabilities of existing radars. At the same time, the continuous development of stealth, high-speed and weak targets also poses severe challenges to modern radars. To this end, it is necessary to study the corresponding technology to meet the challenges, improve the detection capability of the existing radar seeker, and increase the detection distance of weak targets. [0003] At present, the radar seeker usually adopts a high...

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Problems solved by technology

[0003] At present, the radar seeker usually adopts a high repetition frequency waveform, which is converted into a continuous wave signal after the main spectral line is filtered out by a narrow-band filter. The continuous wave signal is digitally sampled and subjected to spectrum analysis to detect whether the target exists. However, due to the weak target The RCS is relatively small. When this method is used to detect weak targets, the maximum range of the radar will become smaller, which will affect the detection performance of existing radars.

In order to increase the maximum operating distance of the radar, it is usually necessary to increase the radar power-aperture product, but under the existing technical conditions, the radar power-aperture product cannot be increased or the cost of increasing it is too high, so the method of signal processing is used to achieve the target in the long-term The accumulation of echo energy within the observation time and increasing the target accumulation time are the main ways to improve the detection performance of weak targets

However, due to the substantial improvement of the maneuverability of various aircrafts and the increasingly strong maneuverability of the target, the velocity of the target will change during the long coherent accumulation time, causing its echo signal to be distributed in multiple Doppler units, thus The Doppler spectrum broadens, the coherent accumulation performance deteriorates, and the detection performance of the system decreases, which in turn reduces the detection distance of the radar and affects the detection performance of the radar.

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