NISAR MISSION (Syllabus: GS Paper 3 – Sci and Tech)

Context: Recently, the Chairman of ISRO provided insights into the latest developments regarding the Nisar satellite project.

NISAR Mission

• Full form: 'NASA-ISRO Synthetic Aperture Radar' (NISAR)
• Joint Development: NISAR, the Low Earth Orbit (LEO) observatory, is a collaborative effort between NASA and ISRO.
• Size and Weight: This SUV-sized satellite boasts a weight of 2,800 kilograms.
• Unique feature: NISAR features both L-band and S-band synthetic aperture radar (SAR) instruments, making it a unique dual-frequency imaging radar satellite.
• The S-band payload has been made by the ISRO and the L-band payload by the U.S.
• Capabilities: To utilize two different radar frequencies (L-band and S-band) for monitoring and measuring changes in the Earth's surface.

o It can monitor the tectonic movements to centimetre accuracy. It can do measurement of water bodies accurately. It can look at water stressing on the earth, wherever there is deficiency of water. It can ground-penetrate to a certain depth.

• All-Weather Observations: The SAR instruments on NISAR are adept at penetrating clouds and can gather data day and night, regardless of prevailing weather conditions.
• Contributions: In the collaborative project, NASA has contributed the L-band radar, GPS, a high-capacity solid-state recorder, and a payload data subsystem. Meanwhile, ISRO has provided the S-band radar, the GSLV launch system, and the spacecraft.
• Gold-Plated Reflector: NISAR incorporates a substantial 39-foot stationary antenna reflector constructed from gold-plated wire mesh. 
• This reflector plays a crucial role in focusing the radar signals emitted and received by the upward-facing feed on the instrument structure.