Descending track spotlight SAR (synthetic aperture radar) positioning method based on image matching

Abstract

The invention discloses a descending track spotlight SAR (synthetic aperture radar) positioning method based on image matching. The method has the technical scheme that 1, a radar positioning geometrical configuration under a NEU coordinate system is built by using a ground point target T as an original point, and an SAR imaging image of the target point T on the imaging plane is obtained; 2, an SAR imaging matching graph is obtained by using a geometric distortion correcting mapping function between the imaging plane and the ground plane; 3, an affine transform matrix between P matching points and the SAR imaging matching graph and the set SAR imaging reference graph is obtained through an imaging matching algorithm, and the distance from the target point T and a sight line point C is obtained by using the affine transform matrix; 4, according to the set sampling frequency, the distance from the radar to the target point T and the distance from the radar to the sight line point C are obtained; 5, the coordinate values of the radar practical position A is calculated according to the results obtained in the steps 3 and 4. The method has the advantages that the precise positioning of a high-squint spotlight SAR can be realized; accurate position information can be provided for radar platform deflection correction.

Description

technical field [0001] The invention belongs to the technical field of radar image target positioning, and in particular relates to a down-orbit spotlighting synthetic aperture radar positioning method, which is suitable for providing accurate position information for radar platform deflection correction. Background technique [0002] Radar is an electronic device that uses electromagnetic waves to detect targets. The principle is that the radar equipment emits electromagnetic waves to irradiate the target and receives its echo, thereby obtaining the distance, distance resolution, azimuth, height and other information from the target to the electromagnetic wave emission point. The advantage of radar is that it can detect long-distance targets day and night, and it is not blocked by fog, clouds and rain. It has the characteristics of all-weather and all-weather, and has a certain penetration ability. Such as weather forecasting, resource detection, environmental monitoring, e...

AI Technical Summary

Problems solved by technology

[0008] The object of the present invention is to propose a descending orbit spotlight synthetic aperture radar positioning method based on image matching, to solve the problem that the positioning accuracy of the SAR platform in the above-mentioned prior art is low, and the problem of high squint spotlight synthetic aperture radar positioning cannot be realized. Provide accurate target scene and radar actual position information for radar platform correction

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