Precession target micro-Doppler extracting method based on instant frequency modulation rate estimation

Abstract

The invention discloses a precession target micro-Doppler extracting method based on instant frequency modulation rate estimation. The precession target micro-Doppler extracting method based on instant frequency modulation rate estimation comprises the steps that (1) an equivalent scattering point model of a spatial precession conical target is established, echo signals of the conical target are received by a radar, echo sequences are obtained from the echo signals by using the equivalent scattering point model; (2) frequency modulation rates of the echo sequences are estimated with a relaxation demodulation line frequency modulation method; (3) the frequency modulation rates of the echo sequences are processed through a random sampling consistency algorithm, and P frequency modulation rate curves are obtained; (4) integral operation is carried out on the P frequency modulation rate curves respectively, and P instant micro-Doppler frequency estimation curves are obtained. According to the precession target micro-Doppler extracting method based on instant frequency modulation, high estimation accuracy can be obtained under the situation of the lower signal to noise ratio. The precession target micro-Doppler extracting method based on instant frequency modulation can be applied to analysis of the micro-Doppler frequency of the spatial precession conical target.

Description

Technical field [0001] The invention belongs to the field of radar technology, and relates to an instantaneous Doppler frequency estimation method, in particular to a micro-Doppler extraction method of a precession target based on instantaneous frequency modulation estimation, which is used to estimate the micro-Doppler of a spatial precession target frequency. Background technique [0002] When a target with a smooth surface is flying outside the atmosphere, in order to maintain the stability of the attitude, it needs to make a spin motion. When it is subjected to lateral interference, it will spin motion while making a cone motion around another directional axis in space. This form of movement is called precession. V.C. Chen of the US Naval Laboratory defined precession as a kind of micro-motion, and named the Doppler modulation in the radar echo generated by micro-motion as micro-Doppler modulation. Since the micro-motion of the target can reflect its structure, size, micro-...

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Problems solved by technology

For example, the micro-Doppler frequency extraction method of spatial cone targets based on multi-target tracking proposed by Shao Changyu et al. This method first applies the classic short-time Fourier transform to obtain the time-frequency distribution map of the echo, and then uses the multi-target tracking technology to track The time-frequency curve on the time-frequency distribution map can be used to extract the micro-Doppler frequency of each equivalent scattering center of the target. Contradictory problems, it is difficult to obtain a higher accuracy of instantaneous frequency estimation; another type of method for instantaneous frequency estimation is the parametric method, which differs from the non-parametric m

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