NLCS imaging method of curvilinear motion bistatic SAR

Abstract

The invention provides an NLCS imaging method of a curvilinear motion bistatic SAR for special scene requirements such as multi-angle target observation. The method comprises the steps that firstly, a Chebyshev polynomial is used for decomposing a slope distance function under the three-dimensional speed and acceleration, and the purpose is to improve the approximation precision of the slope distance function; a linear range walk item is compensated through LRCMC, so that large strabismus is equivalent to small strabismus or front side view imaging, and the processing process of a later algorithm is simplified; aiming at the problem of azimuth time space-variant caused by three-dimensional speed and acceleration, an azimuth nonlinear scaling algorithm is provided, Doppler frequency modulation rates of different point targets are balanced by using a disturbance function, and azimuth filtering of the same distance unit can be carried out under the same parameter, so that the problem of space-variant of the Doppler frequency modulation rates along with azimuth is solved, and the focusing depth and the imaging resolution of the point target are effectively improved.

Description

technical field [0001] The invention belongs to the field of radar signal processing, and in particular relates to an NLCS imaging method of a curved-motion double-base SAR in synthetic aperture radar imaging technology. Background technique [0002] Bistatic Synthetic Aperture Radar (BiSAR) refers to a radar imaging system in which the transmitting platform and receiving platform work separately. Compared with the traditional single-base SAR, it has greater flexibility in use, a longer range of action, and can obtain more abundant information. But at the same time, the separate structure of the transceiver platform also brings some technical challenges. The slope range function of bistatic SAR is the sum of two hyperbolas, which makes the solution of the spectrum function more difficult and increases the complexity of the imaging algorithm. [0003] For special scenarios such as multi-angle observation targets in practical application scenarios, the carrier platform of the...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art, aiming at the needs of special scenes such as multi-angle observation targets in practical application scenes, a kind of NLCS imaging method of double-base SAR with curved motion is proposed, which effectively solves the problems caused by three-dimensional velocity and acceleration. Azimuth-space variability of Doppler modulation frequency, and improve focus performance and imaging quality of point targets

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