Method for detecting non-cooperation pulse compression radar weak target based on wavelet denoising

Abstract

The invention belongs to the technical field of radar signal processing, and particularly relates to a method for detecting a non-cooperation pulse compression radar weak target based on wavelet denoising. The method is characterized in that an echo signal with noise is not directly denoised, but the matched and filtered peak envelope is used as a processed object; an envelope main lobe of the matched and filtered echo signal is remained by the wavelet denoising; after the envelope main lobe of the echo signal is decomposed by wavelets of various scales, the energy is mainly centralized at the low-frequency part, only the setting threshold value of the low-frequency wavelet coefficient after wavelet decomposing is screened, the other decomposing layers are zeroed, then the envelope main lobe of the echo signal is remained, and most of noise is filtered, so as to effectively accumulate the energy of the echo signal through Radon conversion. The method has the advantages that the influence caused by the in-band noise of the echo signal can be eliminated, the signal and noise ratio of the echo signal is improved, the linear detection method can effectively accumulate the target echo energy, the detection probability is finally improved, and the weak target is detected.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, in particular to a non-cooperative pulse compression radar weak target detection method based on wavelet denoising. Background technique [0002] In the modern battlefield environment, the effectiveness and survivability of radars are facing more and more severe tests, especially threats from stealth targets, anti-radiation missiles, low-altitude penetration and electronic jamming. Passive radar uses the electromagnetic signal of the third-party radiation source reflected by the target, that is, the echo signal of the target, to complete the detection and tracking of the target, but it does not emit electromagnetic wave signal itself, so it has good "four anti-characteristics" and has a simple structure. , low cost and other advantages, has aroused widespread concern of scholars. Among them, the pulse compression radar emitting linear frequency modulation (LFM, Linear Formulation...

AI Technical Summary

Problems solved by technology

For pulse compression radar, the echo signal containing white noise can effectively filter out most of the noise after matched filtering, but the remaining noise is aliased with the spectrum of the echo signal

For the in-band noise that is aliased in the frequency domain of the same signal, neither of the above two methods can effectively remove

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