SAR image real-time geometric correction method and system based on RD plane pixel mapping

Abstract

The invention discloses an SAR image real-time geometric correction method and a system based on RD plane pixel mapping. The SAR image real-time geometric correction method comprises two methods of mapping correspondence of an RD imaging plane and a ground distance plane and ground distance pixel scale determination. According to the method, an SAR radar imaging principle is utilized to calculatea distance sampling interval and an azimuth Doppler sampling interval in an original RD imaging plane, pixel coordinates of the original imaging result RD plane are calculated, and ground distance position coordinates of pixels of a real-time SAR imaging result are calculated through an imaging geometrical relationship. Meanwhile, in the pixel ground distance grid positioning process, ground distance pixel scale adjustment is achieved through ground distance position coordinates. The method can be applied to a real-time SAR imaging system, image geometric correction with a simple processing process and high real-time performance can be realized, and the problem of geometric correction of the input image of a real-time airborne / missile-borne SAR scene matching system is solved.

Description

technical field [0001] The invention belongs to the technical field of image processing in the field of remote sensing and guidance, and in particular relates to a method and system for real-time geometric correction of SAR images based on RD plane pixel mapping. Background technique [0002] For the real-time SAR scene matching system, most of its reference images are the ground target features directly below acquired by spaceborne or airborne image sensors. However, due to the imaging principle of the real-time SAR radar imaging platform on the large forward-looking RD plane, the imaging results have obvious oblique geometric distortion compared with the upright and downward-looking reference surveying and mapping images, and the pixel scale of the imaging results also changes due to the different real-time attitudes of the radar. , these two changes severely restrict the matching probability and accuracy of the SAR scene matching system. In order to solve the above contr...

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Problems solved by technology

Non-patent literature (Geometric Correction Algorithm for Missile-borne SAR Images Introduced Coordinate Mapping Principle, Ye Xiaoming) proposed a geometric correction method for the descent section of needle-borne SAR using spectrum analysis to realize the pixel mapping between the RD plane and the ground plane. This method is simple but accurate. It is heavily dependent on the platform height information, and the platform height jitter provided by the inertial navigation equipment will cause a large distortion of the ground distance correction result

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