INSAT-3DR

INSAT-3DR is an Indian geostationary meteorological satellite developed and operated by ISRO, launched on 8 September 2016. The satellite is positioned at 74 degrees East longitude (geostationary altitude 35,786 km), providing continuous coverage of the Indian subcontinent and surrounding ocean regions. WMO OSCAR and MOSDAC both record the satellite at 74 degrees East longitude; CEOS records 93.5 degrees East.^[1][2][3]

The primary Earth-observation payload comprises a six-channel imager and a 19-channel sounder. The imager supports atmospheric motion vector derivation, sea surface temperature retrieval, and broadband radiometry; the sounder performs atmospheric temperature and humidity profiling through limb-nadir sounding. Ancillary payloads include a Data Relay Transponder (DRT) and a Satellite-Aided Search and Rescue (SAS&R) transponder. Application domains span weather nowcasting, atmospheric wind monitoring, precipitation estimation, sea surface temperature, atmospheric profiling, and Earth radiation budget measurement.^[4][5][6]