INSAT–3A, the third satellite in INSAT–3 series is a multipurpose satellite for providing telecommunications, television broadcasting, meteorological and search and rescue services. It carries twenty four transponders – twelve operating in the normal C – band frequency, six in extended C-band and six in Ku–band. INSAT–3A also carries a Ku–band beacon.

For Meteorological observation, INSAT–3A carries a three channel Very High Resolution Radiometer (VHRR). In addition, INSAT–3A carries a Charge Coupled Device (CCD) camera which operates in the visible and short wave infrared bands providing a spatial resolution of 1 km.

A Data Relay Transponder (DRT) operating in UHF band is incorporated for real time hydro meteorological data collection from unattended located on land and river basins. The data is then relayed in extended C–band to a central location.

INSAT–3A also carries another transponder for Satellite Aided Search and rescue (SA&R) as part of India’s contribution to the international Satellite Aided Search Programme.