Indian Remote Sensing Satellites
Remote Sensing effort in India started in late sixties with the aerial survey using multi-data instrument and aircraft carrying variety of sensors like infra-red scanner and multi-specialty scanner, radio meter etc. for monitoring different crops, soil degradation, water pollution, land usage etc. Considering the need to have a global picture on a larger scale, development efforts for remote sensing satellite were pursued. Based on the successful launch of Aryabhata and Bhaskara, new series of remote sensing satellite called IRS were developed.
ISRO has designed and developed high performance remote sensing satellite system for India and the first one, IRS-1A was launched on March 17, 1988 on board a Soviet Vostok Rocket.
The second satellite IRS-1B identical to IRS-1A was launched August 29, 1991. This carried complex payloads like linear imaging Self Scanner – LISS-1 with the resolution of 72.5 m and LISS -2A, LISS -2B with a resolution of 36.25 m. The satellite was placed in 904 km polar sun synchronous orbit with an orbital period of 103 minutes. The satellite return to their original orbital trace every 22 days enabling repeated collection of data over the same place and at the same local time. This was followed by IRS-1C class satellites.
With the PSLV getting operational, IRS-P2 satellites were placed in sun-synchronous orbit on October 15, 1994.
The satellite control center located at Bangalore and other ground stations at different locations regularly track and monitor IRS satellite. National Remote Sensing Agency (NRSA) at Hyderabad receives the data from the IRS satellites. After processing & distribute it to the user agencies.
IRS data has been extensively used to evaluate agricultural crops yield estimate, drought monitoring and assessment, flood mapping, land use and land cover mapping, waste land management, water resource land management, ocean/marine resource survey, urban planning, mineral prospecting, various resource survey etc. The IRS system has become one of the main service sectors of ISRO for the nation.
The TES-Satellite has provided a resolution of better than 1 m in which one could clearly identify the vehicles moving on the road.