GISAT will be fixed in a geo-stationary orbit, always looking over the same region and synchronised to the earth’s 24-hour rotation. GISAT will provide images every five minutes unlike other remote-sensing satellites, which view a particular area for barely ten minutes and do not visit the same place for the next one, three or five days
A 2012-13 Budget grants document for the Department of Space describes GISAT as a “multi-spectral, multi-resolution advanced remote sensing satellite.” Its nearly real-time imagery can speed up authorities’ response to calamities and troubles to almost immediately, Tapan Misra, Deputy Director at SAC’s Microwave Remote Sensors Area, told The Hindu.
Its electronically steerable camera can ‘see’ as small as a 60-metre area from its height of 36,000 km. It will be a marvel up there compared to what ISRO’s low-flying Earth observation satellites can do with their fine resolutions of 2 m, 1m and even less than one metre, said Misra.
“A single early-warning satellite, giving you constant, complete coverage of the country, is unique,” according to Dr. V.Jayaraman, former Director at ISRO’s Hyderabad-based National Remote Sensing Centre.
It would complement the advanced meteorology and remote-sensing satellite, Insat-3D, due to be launched in December this year, said Dr. Jayaraman, who was earlier Director, Earth Observation, ISRO.
GISAT, Misra said, will be built on ISRO’s technologies that went into Cartosat and Radar Imaging Satellite (RISAT-1) — “both of which were big technology leaps for the country.”