Cross calibration of INSAT 3A CCD channel radiances with IRS P6 AWiFs sensor

Abstract

Indian National Satellite (INSAT) 3A was launched in the year 2003 with communication and remot sensing payloads. The later payloads contain very high resolution radiometer (VHRR) and charge couple devices (CCD) camera. In this paper, post-launch calibration of INSAT 3A CCD is discussed. A cros radiometric calibration was carried out with well calibrated advanced wide field of view sensor (AWiFS) o Indian Remote Sensing Satellite (IRS P6). Three concurrent scenes of December, January and Februar were used in this study. Calibration was carried out under different land cover classes such as snow vegetation, forest, water and cloud. Regression analysis suggests correlation coefficient of 0.95, 0.9 and 0.60 for Red, NIR and SWIR channels with slope values 1.839, 1.589 and 2.232, respectively. Ne calibration coefficients were used to estimate at-sensor radiance and reflectance in all the three channels Dynamic range of reflectances was found to be improved by using new calibration coefficients. Normalize difference snow index and vegetation index (NDSI and NDVI) have shown an improvement with ne coefficients and were found closer to represent in situ data of different land covers and cloud. © Indian Academy of Sciences.