Why in News:

• RISAT-2B, will mark the resumption of a vital ring of Indian all-seeing radar imaging satellites after seven years.
• A constellation of such space-based radars means a comprehensive vigil over the country.

Background: / RISAT:

• The RISAT, which was first deployed in orbit on April 20, 2009 as the RISAT-2, uses synthetic aperture radars (SAR) to provide Indian forces with all-weather surveillance and observation, which are crucial to notice any potential threat or malicious activity around the nation’s borders. Following the 2008 Mumbai terror attacks, the launch of RISAT-2 was prioritised over RISAT- 1, as its C-band SAR radar was not yet ready and RISAT -2 carried an Israeli-built X-band radar.
• The to-be-deployed RISAT-2BR1 satellite uses the same SAR band and will further improve India’s imaging reconnaissance abilities.

RISAT-2B

• 4th flight unit of the RISAT programme.
• Main mission: reconnaissance and disaster management. DATA access Information:
• Direct reception at appointed ground stations in X-band.
• Off-line data are distributed by the National Remote Sensing Center (NRSC) in Launch scheduled for 22 May 2019.