Attitude Compensation Method for Agile Satellite Imaging with Pushbroom Velocity Mismatch in Any Direction

Abstract

The invention relates to a posture compensation method for dealing with mismatching of a push-scanning speed for imaging along random direction of a quick satellite. For breaking through the limitation (only taking the deflecting effect caused by earth rotation into consideration) of the posture compensation method under a traditional imaging mode (fixed direction from satellite to earth), the reason why the deflecting effect is generated under the imaging mode with constantly changing posture-to-earth direction (namely, posture-to-earth direction constantly changes under the condition of mismatching between a satellite spot speed and a camera push-scanning speed) when the satellite is used for push-scanning along random direction is analyzed and the imaging deflecting effect is analyzed from three aspects of orbital motion, earth rotation and camera push-scanning speed, thereby acquiring a deflecting angle calculation formula under such a mode according to the track posture parameters and the basic definition of a deflecting angle. Based on the deflecting angle calculation formula and a basic principle of TDICCD (Time Delay Integral Charge-coupled Device) imaging as well as a yawcontrol principle, the posture compensation method, which can meet the imaging requirement for push-scanning along random direction of the quick satellite, is provided.

Description

technical field [0001] The invention relates to an attitude compensation method for agile satellite imaging. Background technique [0002] During the imaging process of optical remote sensing satellites, there will be a certain deviation between the target imaging point and the actual imaging point due to factors such as orbital movement, earth rotation, attitude maneuvering, and camera working push-broom mode. measure. [0003] For the sub-satellite point imaging mode, the calculation formula of the drift angle is mature. For the sub-satellite point imaging mode, Yuan Xiaokang deduced the azimuth offset and pitch offset imaging time The formula for calculating the drift angle of the camera, and a method of using satellite yaw control to compensate the camera drift angle, dynamically changing the configuration direction of the TDICCD line array, so that it is always consistent with the direction of the target image movement; Calculation Model of Velocity-to-Height Ratio" ...

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Problems solved by technology

[0004] (1) In the imaging mode mentioned in the article, the imaging width of the spaceborne remote sensor is small, and the imaging range is small, usually a small circular or rectangular area, which cannot effectively cover the regional target. The target in the imaging area is limited by the visible time window, and the imaging task is single; the attitude compensation technology in the above mode is based on the attitude control of the drift angle when the attitude is fixed to the ground, and the attitude to the ground is controlled when the satellite is pushed in any direction. The drift angle and attitude compensation technology under the condition of constant change has not yet given specific measures;

[0005] (2) In this paper, it is assumed that the moving speed of the sub-satellite point is consistent with the surface push-broom speed of the camera. The attitude compensation technology of the drift angle only considers the drift angle caused by the rotation of the earth. The attitude compensation technology has great limitations: the above The attitude compensation technology in this mode is only suitable for the case where the moving speed of the sub-satellite point is consistent with the speed of the camera push-broom, that is, the situation where the satellite is pushing-broom along the orbit. Case

The satellite attitude compensation method based on the drift angle in the traditional mode (the moving speed of the sub-satellite point is consistent with the camera push-broom speed) can no longer meet the attitude adjustment requirements of agile satellite imaging

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