Method for extracting micro-Doppler parameters of precession cone target under foresight condition

Abstract

A precession cone target parameter extraction method under a foresight condition comprises the following steps: (1) constructing a radar observation model, obtaining scattering point echoes of a precession cone target, multiplying an echo signal by a phase compensation function Scom (tm), and eliminating a micro-Doppler component brought by rotation of an antenna; applying an EMD method to the echo signal after phase compensation to obtain a plurality of intrinsic mode functions (IMFs), extracting each IMF frequency, and realizing effective estimation of a target coning frequency; (2) carrying out time-frequency analysis on the echo after phase compensation to obtain a micro-Doppler curve, and carrying out skeleton extraction on the curve to improve the estimation precision; a broadband radar is arranged at the original point, a high-resolution one-dimensional distance sequence of scattering points is obtained, and geometric parameters and motion parameters of the precession cone target are jointly estimated by combining the coning frequency, the high-resolution one-dimensional distance image and the peak value of the micro-Doppler curve obtained in the above steps. The method can overcome the defect that a single-base radar cannot effectively extract the target micro-Doppler parameters under the condition that the micro-motion plane is perpendicular to the radar sight line direction.

Description

technical field [0001] The invention relates to a signal and information processing technology, in particular to a new method for extracting micro-Doppler parameters of a precession cone target under forward-looking conditions. Background technique [0002] Micro-Doppler is considered to be a unique feature of micro-moving targets. The micro-Doppler effect can be used to achieve complex recognition of cone-shaped targets. However, it is difficult to effectively extract micro-motion features perpendicular to the direction of the radar line of sight. Radars used to extract the fretting features of cone targets can be divided into traditional plane wave radars and vortex electromagnetic wave radars with wavefront phase modulation. Traditional plane wave radars can be divided into monostatic radars and bi / multistatic radars. Monostatic radars can extract radial fretting features, but for fretting components perpendicular to the direction of the radar line of sight, the Doppler f...

AI Technical Summary

Problems solved by technology

However, the angular Doppler frequency shift is closely related to the number of modes. The larger the number of modes, the greater the angular Doppler. The vortex electromagnetic waves used in the field of radar imaging and identification are generated by circular arrays, and the number of array elements increases. more, the greater the number of modes that can be generated, the size of the array limits the size and purity of the number of modes. In the case of a limited array size, the micro-motion characteristics of the target cannot be effectively obtained by using the vortex electromagnetic wave radar. Therefore, the vortex electromagnetic wave radar micro There are still many problems to be solved in the dynamic feature extraction method

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