Method for correcting tracking and aiming beam deviation in satellite-to-satellite SAL (synthetic aperture radar) imaging

Abstract

The invention relates to a method for correcting tracking and aiming beam deviation in satellite-to-satellite SAL (synthetic aperture radar) imaging. The method includes sequential steps of tracking a target by a detector and detecting the angular direction and the speed of movement of the target in real time; carrying out wavelet transform for an acquired angular direction curve of the movement of the target, detecting singular points in the movement of the target, and judging whether beam deviation caused by non-target stars occurs or not; filtering by the aid of a Kalman filtering algorithm if the beam deviation occurs, fitting a least square fitting polynomial by a least square curve, starting a memory tracking program and imaging the target under the condition of memory tracking; returning to the first step if the beam deviation does not occur; and continuing processing position deviation information acquired by the detector in a target imaging process under the condition of memory tracking until the detected non-target stars move out of a viewing field and recovering normal tracking. The problem that tracking and aiming beams are interfered easily and deviate can be solved, and the beam deviation is detected and corrected in real time.

Description

technical field [0001] The invention relates to the field of laser synthetic aperture imaging, in particular to a tracking and aiming beam offset correction method in star-to-satellite SAL imaging. Background technique [0002] Synthetic aperture lidar (Synthetic Aperture Radar, SAL) is an extension of synthetic aperture imaging technology in the optical band, which can make up for the lack of low resolution of radar band synthetic aperture imaging. At present, SAL imaging technology has moved from laboratory research to the practical stage, which provides a potential means for the implementation of high-resolution, long-distance target stereoscopic imaging reconnaissance. [0003] The coherent detection technology used by spaceborne SAL can not only detect the information that can be detected by direct detection, but also detect the phase, frequency, frequency shift and other information inside the echo signal. On the basis of inheriting the advantages of coherent detectio...

AI Technical Summary

Problems solved by technology

The problems of space-borne synthetic aperture lidar imaging for stars include: narrow laser beam, small divergence angle; long transmission distance, large loss of light energy, weak light signal received by the detector; background light such as the sun, moon, and stars interference; satellite platform disturbance affects targeting accuracy

In addition, during star-to-satellite SAL imaging, due to the non-cooperative nature of the target star, the relative motion of the two stars cannot always be accurately predicted; Should be an aid in imaging timing decisions and phase error compensation

[0004] The research on the tracking and aiming system of the interstellar laser link is extensive and in-depth, and the aiming accuracy and response speed have been continuously improved. Rare public reports

Severe beam pointing deviation in star-to-star SAL imaging will cause the SAL line of sight center to deviate from the target, thereby reducing the echo intensity and causing phase errors that are difficult to compensate

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