Geometrical calibration method of satellite CCD (Charge Coupled Device) array image based on high-precision registration control points

Abstract

The invention provides a geometrical calibration method of a satellite CCD (Charge Coupled Device) array image based on high-precision registration control points. The geometrical calibration method comprises the following steps of: extracting a large number of control points at equal intervals according to an image array by utilizing a registering method meeting sub-pixel-level registration accuracy, and calibrating a rigorous geometrical model based on a constructed satellite image to solve a bias matrix; and further solving part of detector cell directional angles in the CCD array based on the calibrated geometrical model, fitting the solved detector cell directional angles by adopting a polynomial model, thereby obtaining all the detector cell directional angles in the CCD array. According to the geometrical calibration method, the bias matrix is introduced into the rigorous geometrical model, so that the geometrical position error caused by load installation deviation and attitude deviation can be well compensated; a detector cell directional model is established and the detector directional angles are directly calibrated; the model selection difficulty of image point deviation is avoided; and the geometrical calibration method has strong applicability and high practical value.

Description

technical field [0001] The invention belongs to the technical field of photography and imaging, and in particular relates to a satellite CCD array image geometric calibration method based on high-precision registration control points. Background technique [0002] At present, the domestically-developed domestic satellites have improved in terms of image visual effects and radiation quality, but there is still a large gap in geometric quality compared with similar foreign satellites. For example, the positioning accuracy of domestic satellites without control points is above 100 meters, while most foreign satellites are on the order of tens of meters; under the condition of sufficient control points, the orthorectification accuracy of foreign satellite images is about 1 pixel, The accuracy of orthorectification of domestic satellite images is 3-4 pixels. [0003] The rigorous geometric imaging model of the satellite CCD array image can be briefly expressed by the following f...

AI Technical Summary

Problems solved by technology

At present, there are many studies on image point offset caused by internal distortion, and various error models have been established, such as linear models such as principal point offset, principal distance error, CCD array scaling and rotation, non-centering distortion, radial distortion, etc. Linear model; for a specific satellite sensor, people cannot know the distortion in the camera in advance, and it is difficult to correctly select the appropriate model to express its image point offset; in addition, it is also difficult to correctly select the nonlinear model that may exist inside the camera The order of the model, it is easy to cause excessive parameters due to the selection of too high order, causing the instability of the solution

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