Frequency Domain Imaging Method for Bistatic Forward-Looking SAR Based on Spectrum Optimization Modeling

Abstract

The invention discloses a bistatic forward-looking SAR frequency-domain imaging method based on spectrum optimization modeling, comprising the following steps: S1, performing data preprocessing to obtain echo signals; S2, performing two-dimensional Fourier transform on the echo signals, Establish the optimal two-dimensional spectrum model of the point target response of the system, and solve the precise two-dimensional spectrum of the point target response through the differential evolution optimization method; S3, carry out rough matching and focusing on the precise two-dimensional spectrum of the point target response; Range-frequency transform; S5. Perform a two-dimensional inverse Fourier transform on the two-dimensional frequency spectrum after the range-frequency transform to obtain a final complex image. The present invention overcomes the problem that the existing imaging algorithm cannot deal with the non-linear spatial variation of bistatic forward-looking SAR range, obtains the accurate two-dimensional spectrum of bistatic forward-looking SAR through the differential evolution optimization method, and obtains the accurate two-dimensional spectrum according to the point target response The imaging processing of the echo signal in the two-dimensional frequency domain can realize the precise focusing of the raw data of the bistatic forward-looking SAR.

Description

technical field [0001] The invention belongs to the technical field of radar, in particular to a bistatic forward-looking SAR frequency-domain imaging method based on spectrum optimization modeling. Background technique [0002] Bistatic forward-looking SAR imaging is a new concept and new system SAR technology with important military applications and civilian values. station, the transceiver beam points to the area directly in front of the aircraft where the receiving station is located, and utilizes the collaboration between the transceiver stations to achieve high-resolution radar imaging directly in front of the aircraft through imaging processing. Its application background is extensive, including autonomous landing, autonomous navigation, material and personnel airdrop, forward-looking reconnaissance, scene matching terminal guidance, etc. [0003] Similar to monostatic SAR, bistatic SAR can perform imaging processing in the azimuth frequency domain to speed up its pr...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the problem that the existing imaging algorithm cannot deal with the non-linear space variation of bistatic forward-looking SAR range, and to provide an accurate two-dimensional spectrum of bistatic forward-looking SAR through differential evolution optimization method. Responding to the precise two-dimensional spectrum, the echo signal is imaged in the two-dimensional frequency domain, which can realize the precise focusing of the bistatic forward-looking SAR raw data. The bistatic forward-looking SAR frequency-domain imaging method based on spectrum optimization modeling

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