An On-orbit Calibration Method for Rolling Shutter Area Scan CMOS Camera

Abstract

The present invention provides an on-orbit calibration method for a rolling shutter area array CMOS camera, which utilizes the relative motion between the camera and the ground scene brought about by the satellite's own motion and agile maneuvering, and performs speed matching with the area array CMOS rolling shutter , adjust the exposure interval between lines to match the time required for the scene to move in the center of the adjacent pixel projected on the focal plane. First, make the rolling shutter direction perpendicular to the relative movement direction of the ground, and select a certain line as the reference line Calibrate the reference row, and then the direction of the rolling shutter is parallel to and opposite to the direction of the relative movement of the ground, and the other rows of the entire CMOS are calibrated on the basis of the reference behavior standard. The on-orbit calibration method of the present invention realizes on-orbit relative radiation calibration for the imaging system error, further determines the response relationship between pixels, and eliminates or reduces the inconsistency of responses between pixels, effectively improving the image quality. quality.

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 photoelectric characteristics and electrical characteristics of peripheral circuits among the image sensors, each pixel has a unique response curve, which is manifested as various random noise and system noise 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 includes on-boar...

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

Images