The Radar Imaging Satellite (RISAT-1), launched by PSLV-C19 on April 26, 2012, has now been placed in its final Polar Sun-synchronous Orbit of 536 km height.
It may be recalled that PSLV-C19 had placed RISAT-1 in a polar orbit of 470 km X 480 km. As planned, on April 27-28, 2012, the satellite propulsion system was used in four orbital maneuvers to raise height of the orbit of RISAT-1 to 536 km. The satellite is now in its final orbital configuration and in good health. In the coming days, various elements of the C-band Synthetic Aperture Radar will be tested and calibrated as a prelude to payload operations.
As compared to the optical remote sensing satellites that depend upon sunlight, the Synthetic Aperture Radar of RISAT-1 transmits its own radar pulses (at 5.35 GHz) to study the objects on Earth. This facilitates
- cloud penetration and
- imaging even without sunlight.
For RISAT-1, imaging sessions around both 6 AM and 6 PM have been chosen.