Bistatic foresight SAR frequency domain imaging method based on frequency spectrum optimization modeling

Abstract

The present invention discloses a bistatic foresight SAR frequency domain imaging method based on frequency spectrum optimization modeling. The method comprises the following steps: S1, performing data preprocessing, and obtaining echo signals; S2, performing two-dimensional Fourier transform of the echo signals, establishing the point target response optimal two-dimensional frequency spectrum mode of the system, and solving the point target response two-dimensional frequency spectrum through adoption of a difference evolution optimization method; S3, performing rough matching focusing of the point target response accurate two-dimensional frequency spectrum; S4, performing distance frequency transformation of the two-dimensional frequency spectrum; and S5, performing two-dimensional inverse Fourier transform of the two-dimensional frequency spectrum after the distance frequency transformation, and obtaining final complex images. The problem is overcome that the current imaging algorithm cannot process the space variation of the bistatic foresight SAR distance to the nonlinearity, an accurate bistatic foresight SAR two-dimensional frequency spectrum is obtained through the difference evolution optimization method, and the echo signals are subjected to imaging process on the two-dimensional frequency domain according to the point target response accurate two-dimensional frequency spectrum to realize the accurate focusing of the bistatic foresight SAR original data.

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...

AI Technical Summary

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

Images