An on-orbit correction method for absolute radiometric calibration coefficients of solar-blind ultraviolet remote sensing cameras

Abstract

The present invention relates to a solar blind ultraviolet camera absolute radiometric calibration equation coefficient in-orbit correction method, wherein a camera is subjected to laboratory absolute radiometric calibration to obtain the absolute radiometric calibration coefficient and the non-uniformity correction coefficient of the camera, the atmosphere background radiation value calculated based on the atmosphere radiation transmission model can be considered as the true background radiance when the camera in-orbit operating meets a certain constraint of the imaging mode, the location and the illumination condition, the background radiance is inverted according to the laboratory absolute radiometric calibration coefficient and the image local gray mean, and a linear regression method is used to analyze the inverted radiance value and the true radiance value so as to achieve the in-orbit correction of the calibration equation coefficient. According to the present invention, according to the solar blind ultraviolet spectrum atmosphere background radiation characteristic, the high-frequency and operational in-orbit absolute radiometric calibration of the solar blind ultraviolet spectrum remote sensor can be supported, and the blank of the in-orbit absolute radiometric calibration method of the domestic camera at the spectrum is filled.

Description

An on-orbit correction method for absolute radiometric calibration coefficients of solar-blind ultraviolet remote sensing cameras technical field The invention relates to an on-orbit correction method for the absolute radiation calibration coefficient of a sun-blind ultraviolet remote sensing camera, which belongs to the technical field of spaceflight optical remote sensing. Background technique Since the 1970s, the United States has successively reflected OGO-4 (1976), S3-4 (1978), DE-1 (1981), VIKING (1986), Polar BEAR (1986) for atmospheric remote sensing detection in the ultraviolet spectrum. ), AURA (2004), most of these ultraviolet detectors use the measurement of ultraviolet stars for on-orbit absolute radiation calibration, such as "Calibration of the Viking Auroral Imager Using Ultraviolet Stars", "Satellite Observations with the VUPIInstrument" and other papers mention the use of single point Absolute radiometric calibration method, there are two problems in this...

AI Technical Summary

Problems solved by technology

Since the 1970s, the United States has successively reflected OGO-4 (1976), S3-4 (1978), DE-1 (1981), VIKING (1986), Polar BEAR (1986) for atmospheric remote sensing detection in the ultraviolet spectrum. ), AURA (2004), most of these ultraviolet detectors use the measurement of ultraviolet stars for on-orbit absolute radiation calibration, such as "Calibration of the Viking Auroral Imager Using Ultraviolet Stars", "Satellite Observations with the VUPIInstrument" and other papers mention the use of single point Absolute radiometric calibration method, there are two problems in this calibration method: First, the proportional coefficient between the camera response and the stellar radiant flux density is determined by imaging the stellar point target. Using this method for radiometric calibration assumes that the camera response characteristic curve Satisfy the proportional relationship y=k x, that is, the offset of the camera’s absolute radiation calibration equation is considered to be 0. If the assumption is not true, it will bring a large radiation calibration error; secondly, because the ultraviolet stellar radiation calibration belongs to point calibration, Due to the influence of the point spread function PSF of the camera system, the point target is imaged as a diffuse spot on the image plane. The size of the diffuse spot is related to the opening angle of the target itself to the system and the PSF. The total radiance statistics of the diffuse spot will inevitably introduce errors.

Images