Method and device for coherent detection of maneuvering targets based on product variable-scale periodic Lu distribution

Abstract

The invention belongs to the technical field of radar signal processing, and in particular relates to a method and device for coherent detection of maneuvering targets based on product-variable-scale periodic L distribution, including: obtaining a Doppler fuzzy target signal model based on the radar transmitting chirp signals; The Puler ambiguity target signal model uses discrete Fourier transform to eliminate Doppler ambiguity and coupling, and obtains the results of Lv distribution at different distance frequencies; and performs the product operation on the results of Lv distribution to realize coherent detection of maneuvering targets. The present invention has good cross-term suppression performance and is suitable for multi-target detection and parameter estimation; without increasing PRF or changing other system parameters, the fuzzy Doppler frequency can be better realized by performing frequency spectrum period extension and estimating the fuzzy Doppler frequency. The detection of Doppler ambiguous targets with constant velocity can be realized by fast Fourier transform FFT and inverse fast Fourier transform IFFT to realize parameter estimation without search, and realize effective detection of maneuvering targets under low signal-to-noise ratio.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, and in particular relates to a method and device for coherent detection of maneuvering targets based on product-variable-scale periodic Lu distribution. Background technique [0002] In recent years, the rapid development of stealth aircraft and unmanned aerial vehicles (UAVs) has put forward higher and higher requirements for the detection of radar maneuvering weak targets. In order to detect such low radar cross-section RCS targets, long-term coherent accumulation is a preferred method. Unfortunately, the resulting problems include not only linear range migration LRM, range warping and Doppler frequency migration DFM, but also Doppler frequency ambiguity due to high speed of the target or low pulse repetition frequency PRF of the radar. These unfavorable factors will seriously affect the detection performance of traditional accumulation algorithms such as MTD. Therefore, how t...

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Problems solved by technology

However, they will suffer severe cumulative performance loss due to neglect of range bending and DFM effects induced by target acceleration

To solve the above problems, representative methods include generalized RFT or GRFT, Radon Lu distribution algorithm RLVD, KT and Lu distribution algorithm KT-LVD, KT and linear canonical transformation KT-LCT, improved axis rotation transformation and Lu distribution MART-LVT, As well as search algorithms such as improved axis rotation and fractional Fourier transform IAR-FRFT, these algorithms show excellent detection performance at low SNR through parameter search; however, the huge computational complexity makes it unacceptable in practical applications

In addition, non-search algorithms, including adjacent cross-correlation function ACCF, symmetric autocorrelation function-variable-scale Fourier transform SAF-SFT, frequency second-order phase difference FD-SoPD, and three-dimensional variable-scale transform TDST, etc., compared to Search-like algorithms, these methods can achieve lower computational complexity, but at the expense of noise immunity

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