On-orbit calibration method of roller shutter area array CMOS camera

Abstract

The invention provides an on-orbit calibration method of a roller shutter area array CMOS camera. Speed matching is carried out on an area array CMOS roller shutter by utilizing the relative movementbetween the camera and a ground scene caused by satellite movement and agile maneuvering; the exposure interval time between rows is adjusted to match time required by movement of the projection of ascenery on the focal plane at the central position of the adjacent image element. The roller shutter direction is made to be perpendicular to the relative movement direction of the ground and a certain row is selected as a reference row to conduct reference row calibration; the roller shutter direction is parallel to and opposite to the ground relative movement direction in an opposite direction;and other rows of the whole CMOS is calibrated on the whole by using the reference row as a standard. With the provided on-orbit calibration method, on-orbit relative radiometric calibration is realized for the imaging system error; the response relationship among the pixels is further determined; the response inconsistency among the pixels is eliminated or reduced; and the image quality is effectively improved.

Description

technical field [0001] The invention relates to the field of on-track calibration, and more specifically, relates to an on-track calibration method of a rolling shutter area array CMOS camera. Background technique [0002] Due to the differences in the photoelectric characteristics and the electrical characteristics of the peripheral circuits between the image sensors, each pixel has a unique response curve, which is manifested as various random noises and system noises on the image. In order to balance the image and improve the quality, it is necessary to perform relative radiation calibration on the image sensor, use high-precision radiation calibration benchmarks to calibrate the imaging system error, determine the response relationship between pixels, and give the relative radiation of each pixel according to statistical calculations Scaling factor to eliminate or reduce response inconsistency across cells. [0003] At present, on-orbit relative radiometric calibration ...

AI Technical Summary

Problems solved by technology

Among them, the on-satellite calibration method requires high-precision radiation references such as calibration lights or diffuse reflectors on the satellite. Sites, such as deserts, oceans, snow fields, etc.; the statistical calibration method is a probabilistic statistical method based on massive sample information, which needs to process a large amount of data, and its theory has the assumption characteristics of likelihood estimation, which cannot achieve high accuracy

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