RADIOMETRIC CALIBRATION OF HIGH RESOLUTION OPTICAL SENSOR USING ARTIFICIAL TARGETS

摘要

In-flight radiometric calibration of satellite optical sensors require a large number of field measured data (sub-satellite ground based measurements of atmospheric parameters and surface reflectance data) synchronous to satellite pass. This requires more number of field campaigns, resulting in much greater human efforts which in turn makes it a tedious and time consuming process. Also, traditional approach for post-launch radiometric calibration requires the use of radiative transfer code, the accuracy of which in turn affects the accuracy of the calibration of the satellite sensors. This study estimates the calibration coefficients with only one date data by utilizing the artificial targets for high resolution optical sensors. Two independent approaches were used for the estimation. One being the vicarious calibration and using radiative transfer code 6S, which is popularly used worldwide and other being physics based simple analytical approach eliminating the need of radiative transfer code. Both the vicarious and analytical approach show almost the similar results with difference less than 5% in the estimated mean value of multiplicative factors. The insignificant difference between the results estimated from the two methodologies shows the potential of analytical approach with one date data and artificial targets for the estimation of the calibration coefficient without using radiative transfer model. This exercise will help in the radiometric calibration of upcoming high resolution optical sensors using one date ground measurements only.