On accuracy of radiometric calibration of hyperspectral visible/NIR satellite remote sensing instruments using test sites of different altitudes

摘要

To provide accurate data the regular on-board absolute radiometric calibration of a satellite hyperspectral instrument is required. Together with the internal calibration the external calibration using comparison of radiance measurements above special ground test sites and calculated radiances is performed. The top of the atmosphere radiances are calculated using a radiative transfer model basing on atmospheric and surface characteristics measured at the test sites. The paper presents preliminary results of the comparative theoretical analysis of the errors of a satellite hyperspectral instrument radiometric calibration using test sites located at 200 m.a.s.l. and 2000 m.a.s.l. with the atmospheric composition and surface reflectance measurements. The analysis is performed for an instrument with the spectral resolution of 1-8 run which is typical for special regime of payload GSA of Russian satellite Resurs-P. The errors related with the atmospheric composition and albedo measurement errors and scenarios of the aerosol vertical distribution were theoretically examined. The error is less than 4% in all the cases at all the wavelengths between 400 run and 1000 nm with the exception of the absorption bands of water vapor. In the absorption bands of water vapor about 720 nm and 820 nm the errors reach 5% at the mountain site and 10% at the downcountry site. In the absorption band of 950 nm the errors reach 15% in mountains and 35% in downcountry.