Relative radiation correction method for wide-view-field linear array CCD (Charge Coupled Device) camera

Abstract

The invention relates to a relative radiation correction method for a wide-view-field linear array CCD (Charge Coupled Device) camera, which comprises the following steps: (1) selecting a uniform scene image; (2) dividing sub view fields by dividing detection image elements of the linear array CCD camera into different view fields by separating the view field angles of the wide-view-field linear array CCD camera at preset angular intervals; (3) calculating the widths of different sub view fields and the number of the contained detection image elements; (4) calculating an average value of the detection image elements DN in each of the sub view fields and calculating a yield value of the detection image elements in each of the sub view fields, according to the obtained number of the detection image elements; (5) on the basis of the sub view fields at the angular intervals, re-dividing the sub-view-fields into different sub-view-field areas at equimultiple angular intervals according to the multiple of the angular intervals, repeating the steps (3) and (4) for different areas, thereby performing uniform scene calculation on the sub-view-field areas at different multiple angular intervals; and (6) integrally fitting different yield values of the detection image elements in each of the sub view fields obtained by calculating the sub-view-field areas at different multiple angular intervals, thereby obtaining a relative radiation correction coefficient of the wide-view-field linear array CCD camera.

Description

technical field [0001] The invention relates to a relative radiation correction method of a wide field of view linear array CCD camera, in particular to a relative radiation correction of a multispectral camera of an environmental disaster reduction satellite. Background technique [0002] The field of view of the linear array CCD camera limits the swath width of the scan, which makes the remote sensing data limited in realizing all-weather and all-weather earth observation. By increasing the length of the linear array CCD and increasing the field of view, the The swath width scanned by the sensor increases, but the response rate at the edge of the field of view is low. Due to the limitation of the radiance measurement technology, it is difficult to obtain as comprehensive ground information as possible. Large, for this reason, two linear array CCD cameras with a small field of view and a certain angle between the optical axes are used for field of view stitching, so as to a...

AI Technical Summary

Problems solved by technology

[0003] In an ideal state, the gray value output by each pixel of the linear CCD camera is proportional to the input radiance, but due to the inconsistency of the pixels of the CCD detector, each tap, each detector and the system circuit The existence of various unstable factors such as the difference of the difference between the corresponding relationship does not exist. Therefore, the inconsistency between the pixels of the linear array CCD is corrected by relative radiation correction. Statistical method, this method has a good effect on the relative radiation correction of the single-lens linear array CCD camera that lacks the calibration data of the whole star docking before launch and fails to obtain the internal calibration data on the star after launch; The relative radiation correction effect of the wide-field linear array CCD camera with a certain angle of inclination is not very ideal, because this method does not consider that the linear array CCD is inclined at a certain angle, which will introduce pupil distortion, pupil distortion and image plane distortion caused by telecentricity. Non-linear edge dimming of illuminance, which is a major source of error in the response non-uniformity of wide-field line array CCD cameras

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