A Method of On-orbit Relative Radiometric Calibration for Area Array Camera Based on Satellite Attitude Adjustment

Abstract

An on-orbit relative radiation calibration method for an area array camera based on satellite attitude adjustment. Before the satellite performs attitude adjustment to image the ground, it is necessary to set the CCD imaging parameters of the focal plane of the satellite to be consistent; Can be covered by multiple lines of satellite imaging; under the condition that the uniform dark target can be covered by multiple lines of satellite imaging, adjust the satellite to the normal attitude to obtain the image of the uniform dark target, count the DN value of the image, and take the average DN value as the system dark signal ;The satellite performs attitude adjustment so that the direction of the long side of the satellite CCD area array is consistent with the flight direction of the satellite, and then images the ground to obtain a ground image, and the satellite returns to the normal attitude of the satellite; image processing is performed on the ground image, and the processed image is in-orbit Relative calibration, according to the consistency of the satellite operation and the response of the area array optical camera, the relative radiometric calibration coefficient is dynamically obtained to ensure the relative calibration accuracy on the orbit.

Description

technical field [0001] The invention relates to an on-orbit relative radiation calibration method for an area array camera based on satellite attitude adjustment, and belongs to the technical field of radiation calibration. Background technique [0002] Imaging optical cameras will be calibrated on the ground before the satellite is launched, but they must be recalibrated after they are in orbit to eliminate the degradation of imaging performance caused by the drift of calibration coefficients and particle pollution. Since these scaling changes are more or less independent between probes, on-orbit relative scaling is necessary. Relative calibration, as the name implies, does not require the transfer or calibration of absolute radiation values, but only focuses on the radiation response performance differences between the detectors of each channel of the photoelectric imaging / detection system and between the array detector pixels and how to eliminate such differences . The ...

AI Technical Summary

Problems solved by technology

In the sunlit area, the ocean is an ideal uniform field but the brightness is not enough to calibrate the entire dynamic range of the device well

There are many relatively uniform desert targets in North Africa, but not large enough for on-orbit relative calibration of most optical cameras

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