Any of a series of eight remote-sensing satellites built in India and launched between 1988 and 1999. The early ones were placed in orbit by the USSR (later Russia). IRS-1A was launched in 1988, IRS-1B in 1991, IRS-P2 in 1994, IRS-1C in 1995, IRS-P3 in 1996, IRS-1D in 1997, and IRS-P4 in 1999. The latter, also known as Oceansat, carries two payloads, an ocean colour monitor (OCM), and a multi-frequency scanning microwave radiometer (MSMR). IRS-1E was launched in 1993 but failed to orbit.
Subjects: Astronomy and Astrophysics.