Quality assessment of Outgoing Longwave Radiation (OLR) derived from INSAT-3D Imager: Impact of GSICS correction

The INSAT-3D Outgoing longwave radiation (OLR), a fast-delivery level-2 product at pixel resolution, is being generated operationally from every half hourly acquisition of Imager Payload of INSAT-3D. In addition to this, binned daily and monthly OLR products are also generated. The OLR is estimated from the radiance observations in the infrared windows (TIR1: 10.3-11.3 mu m, TIR2: 11.5-12.5 mu m) and water vapor (WV: 6.5-7.1 mu m) channels of INSAT-3D Imager. In the present study, OLR estimated using the INSAT-3D Imager radiance observation is validated with the CERES (Cloud and Earth's Radiant Energy System; on board NPP satellite) from February, 2014 to December, 2017. For the uniform scenes, OLR estimated using INSAT-3D Imager radiance is of good quality with mean CC 0.93, bias -5.03 Wm(-2) & RMSD 10.39 Wm(-)(2) and it could be used in the various applications studies.