Method for computing and calibrating drift angle of spaceflight TDICCD camera by ground control point

Abstract

The invention relates to a method for computing and calibrating a drift angle of a spaceflight TDICCD camera by ground control points. The method comprises the following step of: computing and calibrating the deviation of the drift angle when the spaceflight TDICCD camera is used for imaging by detecting the change of the angle of a control point of an object space and the change of the angle of a control point of an image space. According to the method for computing and calibrating the drift angle of the spaceflight TDICCD camera by the ground control points, provided by the invention, the drift error when the spaceflight TDICCD camera is used for imaging can be exactly measured, the test of the fixed error between a satellite and the camera can be improved, the drift error can be quantized, and the problem of the non-real-time and inexact computation of the drift can be solved.

Description

technical field [0001] The invention belongs to the technical field of aerospace measurement, in particular to a method for calculating and calibrating the drift angle of an aerospace TDICCD camera by using ground control points. Background technique [0002] At present, with the continuous development of aerospace technology, aerospace cameras are gradually developing to high resolution, and all use telephoto reflective optical systems. In order to improve the imaging resolution, there are several typical ways, that is, reducing the orbital height of the satellite plane, increasing the focal length of the aerospace camera and reducing the pixel size of the TDICCD device. Orbit height is generally limited by imaging reconnaissance and orbit planning. Once determined, it is difficult to change. Even changing orbit imaging will consume a lot of satellite platform resources and is rarely used. [0003] As the focal length of space cameras increases and the pixel size decreases...

AI Technical Summary

Problems solved by technology

Although the pointing axis of the satellite platform and the imaging optical axis of the aerospace camera are calibrated on the ground, the relationship between the platform and the camera will inevitably change slightly during the satellite launch process. For a high-resolution imaging system, this small change will It affects the imaging quality, and the satellite measurement unit also has drift, error, and satellite orbit error, etc., which will affect the imaging quality. One of the key factors is the bias angle error or the accumulated bias angle error.

At the same time, the lifespan of aerospace TDICCD cameras is generally more than three years, and the imaging bias error will continue to change with the drift and error accumulation of the satellite platform measurement unit, which will affect the imaging quality

[0005] At the same time, the current satellite platform usually has a time lag (about a few ms) and a large time gap (about 1s) for the measurement of the drift angle and the release of information to the aerospace camera, while the imaging length of the actual aerospace TDICCD camera reaches several Kilometers, or even tens of kilometers, at this time, the drift angle calculated on the orbit cannot reflect the drift angle error state of the imaging in real time, which has a great impact on the real-time imaging space camera

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