A Method of Micro-movement Extraction of Multi-scattering Points Based on ISAR Image

Abstract

The invention provides a multi-scattering point micro-motion extraction method based on an ISAR image. The multi-scattering point micro-motion extraction method is characterized in that S1, a plurality of strong scattering points of the ISAR image in a same range cell can be selected; S2, a frequency domain signal of each strong scattering point can be extracted in a windowing manner, and can be changed into a time domain signal; S3, the phases of the time domain signals can be extracted, and according to the least square method, a phase change curve caused by three-order polynomial fitting rotation, and a micro-motion phase change curve can be acquired after the rotation compensation of the time domain signal by using the phase change curve, and echo data can be acquired after the rotation compensation according to the phase change curve; S4, the micro-motion frequency of the echo data after the rotation compensation can be estimated by adopting the cosine phase model and the simulated annealing algorithm. By adopting the above mentioned method, the micro-motion frequencies of the plurality of scattering points can be effectively and quickly extracted, and the wide application prospect can be provided.

Description

technical field [0001] The invention relates to a multi-scattering point fretting extraction method based on an ISAR image, and belongs to the technical field of signal processing. Background technique [0002] Fretting can be defined as the mechanical motion of a component other than the overall motion of the target (translation). The manifestation of micro-motion on the frequency spectrum is the micro-Doppler phenomenon, that is, there will be side lobes near the Doppler frequency generated by the movement of the target body, which is called micro-Doppler. Micro-motion components contain subtle features of the target, and these features (rotation frequency, rotation radius, etc.) have great application value for target recognition. Therefore, the analysis of radar target features with micro-motion structures has attracted extensive attention of researchers. [0003] Inverse Synthetic Aperture Radar (ISAR) is a high-resolution imaging radar. Through the method of target tr...

AI Technical Summary

Problems solved by technology

Time-frequency analysis is an important tool for studying fretting. Time-frequency transformation can be performed on the signal in a certain distance unit to observe the time-frequency distribution characteristics of the signal. However, when the actual fretting frequency is very small, the time-frequency distribution of each scattering point characteristics also cannot distinguish the fretting component

Moreover, when there are echo signals of multiple scattering points in the same distance unit, the time-frequency distribution of each scattering point on the time-frequency diagram is intertwined and it is more difficult to distinguish

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