Scaling inverse Fourier transformation imaging method of bistatic synthetic aperture radar (SAR)

Abstract

The invention discloses a scaling inverse Fourier transformation Chirp-Z imaging algorithm suitable for bistatic synthetic aperture radar (SAR) and mainly solving the problem of unsatisfactory imaging effect under a long baseline situation in the prior art. The method comprises a first step of adopting geometrical relation formula method GBF to obtain a two dimensional spectrum expression of signal strict parsing, a second step of taylor expression of the two dimensional spectrum expression at distance wave number fundamental frequency and keeping to a quadratic term, a third step of phase compensation of the distance frequency quadratic term by using a parameter of a reference point, a fourth step of space-variant range cell migration correction to signals after twice phase compensation through Chirp-Z scaling algorithm, a fifth step of azimuth compression to the signals after cell migration correction, and a sixth step of obtaining a final imaging result through one inverse Fourier transformation. The scaling inverse Fourier transformation imaging method of the bistatic SAR can achieve fast imaging treatment of bistatic SAR signal under the long baseline situation, an imaging process only needs fast Fourier transformation and phase complex multiplication operation, and the method is high in efficiency and suitable for real-time imaging.

Description

technical field [0001] The invention belongs to the technical field of radar and relates to imaging simulation, in particular to a bistatic synthetic aperture radar (SAR) imaging method, which can effectively process bistatic SAR data under long baseline conditions. Background technique [0002] Because the transmitting antenna and receiving antenna are installed on different platforms, bistatic SAR has many advantages that monostatic SAR does not have. It has broad application prospects in military applications, resource surveys, and crustal deformation monitoring. s concern. [0003] However, unlike monostatic SAR, the slant range history of bistatic SAR is the sum of double root signs, and the precise two-dimensional spectrum of the target cannot be obtained directly using the principle of the stationary phase point. The high-precision bistatic spectrum is the premise of designing fast imaging algorithms in the frequency domain. In recent years, a variety of bistatic spe...

AI Technical Summary

Problems solved by technology

However, these spectra are approximate spectra under certain conditions, and the imaging algorithms designed based on these spectra cannot deal with bistatic SAR data in the case of long baselines

[0004] Although the time-domain method can realize data processing in the case of long baselines, it requires a large amount of calculation and is inefficient.

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