High-resolution imaging method for missile-borne SAR level flight section based on spherical model and FENLCS algorithm

Abstract

The present invention discloses a high-resolution imaging method for missile-borne SAR level flight based on a spherical model and a FENLCS algorithm, and accurately reveals azimuth variation relationship between a point target and beam center distance on a same range unit after the above-mentioned range processing. The high-order range migration of the azimuth variation is modeled with the relationship; the residual range migration of azimuth edge points is removed by combining the KT transform with a residual high-order range migration correction of the azimuth variation; and the accuracy of range processing is further improved. Based on the model, the invention proposes a FENLCS imaging processing method and realizes the removal of the residual Doppler center of the variation and equalization of the Doppler high-order frequency rate. The simulation results verify that the three-dimensional equidistant spherical model deduced by the invention and the corresponding signal processing algorithm are effective under the condition of high-resolution missile-borne level flight. The SAR echo data of the invention has better focusing effect under the missile-borne level flight high-resolution imaging condition.

Description

technical field [0001] The invention belongs to the field of signal processing, and relates to the imaging of missile-borne SAR in level flight (high resolution, wide surveying swath amplitude, large squint), and the high-speed imaging under the complex condition that the radar echo characteristic changes due to the oblique viewing angle of the distance space variation. Quality SAR imaging processing jobs. Background technique [0002] Since the development of synthetic aperture radar imaging, missile-borne SAR, as an important development direction of synthetic aperture radar, has broad application prospects and important application value. In the modern battlefield, missile-borne radar not only needs to have the ability to detect targets in real time, but also needs to quickly and real-time obtain high-resolution images of ground targets to achieve accurate target imaging and recognition. However, with the increasing demand for high resolution, wide survey swath, and larg...

AI Technical Summary

Problems solved by technology

[0005] The traditional method ignores the problem that the spatial squint angle varies with distance and space, and cannot be applied to the imaging processing of the large squint wide swath during the level flight of the missile-borne SAR.

Images