METSAT is the first exclusive meteorological satellite built by ISRO. METSAT is a geostationary satellite that was launched by an upgraded, four-stage PSLV-C4 rocket from the Satish Dhawan Space Center, SHAR on 12 September 2002. It was for the first time that PSLV launched a satellite into a geosynchronous transfer orbit; in all its previous flights, PSLV was used to place Indian Remote Sensing Satelittes and other auxiliary payloads in Polar orbits. Major changes made to PSLV include improvements in the performance of the third stage solid propellant motor by optimizing the motor case and propellant loading. The propellant in the fourth stage liquid propellant motor has been increased from 2 metric tons to 2.5 metric tons. The vehicle also employs a carbon composite payload adapter resulting in substantial payload advantage. The triaxially-stabilized 550 W METSAT weighs 1,060 kgs, carries a VHRR (Very High Resolution Radiometer) scanning radiometer for three-band images: one in the visible, the second in the thermal infrared and the third in the water vapor infrared bands, each at a spatial resolution of 2-km x 2-km resolution, to obtain atmospheric cloud cover, water vapor and temperature. It also carries a Data Relay Transponder (DRT) to provide data from unattended fixed/mobile ground level weather platforms. It was maneuvered from the transfer orbit to a geostationary at 37°E longitude on 16 September, and then to the final parking at 74°E longitude on 24 September.