Radiometric Calibraiton And Application Of Viirs Low-Light Channel Data

Accurate radiometric calibration of remote sensing data is the premise of remote sensing information quantification,and it is the basis for effective data applications in various fields.Based on the analysis of its on-board calibration method,this thesis focuses on the critical technique and scientific problem on the nighttime VIIRS low-light channel,and radiometric calibration and its application of low-light channel data are studied.Especially,nighttime vicarious calibration under low-light conditions,nighttime calibration based on various ground light sources,and applications of low-light channel data are analyzed in depth,providing technology accumulation for operational applications of domestic low-light payloads.For nighttime vicarious calibration under low-light conditions,Dunhuang radiometric calibration site of China Meteorological Administration is used as the vicarious calibration test site,and a nighttime low-light vicarious calibration scheme based on the Dunhuang site is proposed.The selection criteria for effective observation events is determined.The long-term calibration results show that the average relative error between the simulated radiance and the observed radiance is-6.2%,and the total uncertainty is 8.6%.Therefore,the feasibility of nighttime low-light vicarious calibration is verified.For nighttime calibration based on various ground light sources,starting from the existing common metal halide,its basic parameter,arrangement form,and working mode are analyzed.The expected radiance difference between the target pixel and background pixel are derived.The model of upward light radiation is established,and the low-light calibration scheme based on the common metal halide is proposed.The calibration experiment using satellite observation data is performed,and the relative errors between the simulated radiance difference and the observed radiance difference are 3.9%,16.5%,and 19.1%,respectively.Therefore,the feasibility of low-light calibration based on ground light sources is preliminarily verified.Then,aiming at the problem of low-light calibration based on the common metal halide,a specialized light source suitable for nighttime low-light calibration is designed and developed,which has certain radiation intensity uniformity,and the low-light calibration scheme based on this light source is given.Based on the test and analysis of its light characteristics in the laboratory,three field calibration experimens are performed,and the relative errors are 14.8%,13.4%,and 5.4%,respectively.Therefore,the feasibility of this scheme is preliminarily verified.Finally,to further improve the calibration accuracy and applicability,a field low-light calibration light source based on the integrating sphere is designed and developed,which has good radiance uniformity and stable emission radiation.The expected radiance difference between the target pixel and background pixel are derived.The model of upward light radiation is established,and the low-light calibration scheme based on the integrating sphere light source is proposed.Based on the test and analysis of its radiative characteristics in the laboratory,the low-light calibration experiment based on the integrated sphere light source is performed in the Dunhuang site.The average relative error is-8.30%,and the total uncertainty is 8.35%.For applications of low-light channel data,the parameter measurement method using low-light data via the two-dimensional S transform is explored for atmospheric gravity waves,and the horizontal wavelength and propagation direction of gravity waves orginated from tropical cyclone Manhasen at night are effectively obtained.Meanwhile,referring to the daytime sun glint mechanism for ocean internal waves,a parameter measurement scheme for the nighttime horizontal wavelength and propagation direction with moon glint is proposed.Also,the paired daytime and nighttime internal wave observation images near Dongsha Atolls are used to obtain the propagation phase speed by superposition of paired internal wave information.