Method for removing target detection Doppler dispersion of broadband signals based on sub-band processing

Abstract

The invention relates to a method for removing target detection Doppler dispersion of broadband signals based on sub-band processing, and belongs to the technical field of radar target acquisition. According to the method, a direct wave is decomposed into a plurality of sub-bands, phase-coherent accumulation is conducted on each sub-band, plural superposition is conducted on a phase-coherent accumulation result of each sub-band, and a final CAF output result is obtained. In order to make a target peak value accumulated by each sub-band be located on the same Doppler unit, different accumulation time needs to be selected according to a carrier frequency of each sub-band. Compared with a traditional Keystone transform method, a sub-band method is free of the hypothesis that the signal waveform is unchanged, and avoids the signal to noise ratio loss caused by the hypothesis that the signal waveform is unchanged. The method obviously removes the target Doppler dispersion through the sub-band method, effectively improves the phase-coherent accumulation grain, accordingly, improves detection performance of a system, and is especially suitable for being used on application occasions for detecting high-speed targets with long-time accumulation adopted.

Description

technical field [0001] The invention relates to a method for eliminating Doppler dispersion of broadband signal target detection based on sub-band processing, and belongs to the technical field of radar target detection. Background technique [0002] The external radiation source radar uses the emission signals of various non-cooperative radiation sources existing in space to detect targets, and is a special dual multistatic radar. Because of its low cost and good electromagnetic compatibility, it has been widely valued. Commonly used non-cooperative radiation signals include FM radio signals, analog TV signals, digital TV signals, etc. Among them, the digital TV signal is an ideal irradiation source for the external radiation source radar. First of all, digital TV signals are replacing analog TV signals; secondly, digital TV uses digital modulation technology, and the transmission power is stable; moreover, the pseudo-random characteristics of digital modulation make the ...

AI Technical Summary

Problems solved by technology

[0014] Due to the Doppler dispersion effect, the target energy will be dispersed in multiple Doppler units after the digital TV external radiation source radar uses the mutual ambiguity function (CAF) to complete the coherent accumulation, resulting in a decrease in the accumulation gain

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