Sea clutter suppression method based on two-stage Doppler correlation discrimination

Abstract

The invention discloses a sea clutter suppression method based on two-stage Doppler correlation discrimination. The main idea is that MxN-dimensional time-distance two-dimensional echo signals are acquired, and an M1xN-dimensional echo signal matrix S through zero frequency FIR filtering is obtained, wherein M1=M-m+1, and m refers to the maximum order of the zero frequency FIR filter; an M2xM1-dimensional Doppler frequency value matrix f<^><d> is obtained according to the M1xN-dimensional echo signal matrix S through zero frequency FIR filtering, wherein M2=M1-1 and N1=N-4, an M3xM2-dimensional binary matrix is obtained according to the M2xM1-dimensional Doppler frequency value matrix f<^><d>, wherein M3=M2-1, N2=N1-m'+1, m' refers to the number of the distance units included in the set distance unit window, and a time-distance two-dimensional Doppler value matrix f through resetting of two-stage Doppler correlation discrimination is obtained according to the M3xM2-dimensional binary matrix and the size is M3xM2-dimensional; and the sea clutter suppression result based on two-stage Doppler correlation discrimination is obtained according to the time-distance two-dimensional Dopplervalue matrix f through resetting of two-stage Doppler correlation discrimination.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, in particular to a sea clutter suppression method based on two-stage Doppler correlation discrimination, which is suitable for practical engineering applications. Background technique [0002] Radar suppression of sea clutter technology is an important branch in the field of radar signal processing. Target detection in the background of sea clutter has always been a difficult problem; due to the reflection of the sea surface, the echo signal received by the radar contains a large amount of sea clutter energy, making the target easy to be detected. Inundation; and when the high-resolution radar illuminates the rough sea surface at a low grazing angle, the radar echo signal may even appear "sea clutter spike effect", which is prone to false targets. Different from simple ground clutter, sea clutter exhibits obvious non-stationarity and non-Gaussian characteristics with the change of...

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Problems solved by technology

[0003] Although people have successively adopted non-Gaussian sea clutter models such as lognormal distribution, Weibull distribution, and K distribution to fit sea clutter to achieve target detection, due to many variables of radar and sea conditions, this method based on the measured sea clutter The method of researching prior clutter statistical characteristics and establishing a specific sea clutter model to achieve target detection is still not good enough and not universal; in traditional radar signal processing, moving target indication (MTI), moving target Detection (MTD) and other frequency-domain filtering methods suppress clutter and realize target detection; however, since the Doppler spectrum of sea clutter is usually wide, the measurement of the center of the clutter spectrum and the estimation of its spectral width become difficult problems

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