Star camera in-orbit calibration attitude determination and remote sensing image geometric positioning method and system

Abstract

The invention provides a star camera in-orbit calibration attitude determination and remote sensing image geometric positioning method and system. The method comprises steps of after star point identification is completed and control points extracted from a star map are obtained, establishing observation vectors of star points in a J2000 coordinate system, establishing a distortion model and an imaging model of a star camera, and obtaining coordinates of the star points in a star camera coordinate system under mirror distortion; establishing a single star point error equation according to theimaging model of the star camera and the coordinate observation value of the star point in the star camera coordinate system; according to the sequence star map, obtaining an error equation set for simultaneously determining calibration parameters and attitudes of the star camera; inputting the rough laboratory calibration parameters and the rough initial attitude as initial values, and simultaneously determining the calibration parameters and attitude of the star camera by using a least square method to obtain an on-orbit calibration attitude result of the star camera. Compared with the traditional method, the method provided by the invention has higher calibration attitude precision, and has good robustness and fault tolerance, and thereby the direct geometric positioning precision requirement of the current high-resolution remote sensing image is met.

Description

technical field [0001] The invention belongs to the field of aerospace photographic silhouette measurement, aims at high-precision star sensors, and relates to high-precision star camera attitude determination and remote sensing image geometric positioning technical solutions. Background technique [0002] With the continuous development of aerospace technology and the continuous improvement of satellite resolution, the requirements for geometric positioning accuracy of high-resolution remote sensing images are also getting higher and higher. The factors that affect positioning accuracy mainly include satellite orbit determination accuracy, satellite attitude determination accuracy and The calibration accuracy of the ground camera. At present, the satellite orbit determination technology and the ground camera calibration technology are relatively mature, but the satellite attitude determination technology has not yet met the requirements. To achieve meter-level positioning ac...

AI Technical Summary

Problems solved by technology

This attitude solution process has high requirements for star camera calibration. When the performance of the star camera is not high enough and the number of control points obtained is not enough, the main distance and camera distortion parameters calculated by the star camera calibration will have large errors. And the robustness is poor. For the same star camera, using data from different sky areas, the main distance and distortion parameters calculated by the traditional star camera calibration method will be quite different, which does not conform to objective cognition

Inputting inaccurate calibration parameters into the traditional star camera imaging pinhole model for attitude determination, the obtained attitude data will also have a large error, which is difficult to meet the growing demand for high-precision positioning of high-resolution remote sensing images

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