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

Context: The 'NASA-ISRO Synthetic Aperture Radar' (NISAR) is poised to facilitate the exploration of how shifts in Earth's forest and wetland ecosystems impact the global carbon cycle and influence climate change.

'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.
• Dual-Frequency Radar: NISAR features both L-band and S-band synthetic aperture radar (SAR) instruments, making it a unique dual-frequency imaging radar satellite.
• Capabilities: To utilize two different radar frequencies (L-band and S-band) for monitoring and measuring changes in the Earth's surface.
• 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.

Objectives

• The mission aims to collect data on Earth's evolving ecosystems, dynamic surfaces, and ice masses. 
• This data will offer insights into biomass, natural hazards, sea level rise, and groundwater.
• NISAR is designed to provide global coverage of Earth's land and ice-covered surfaces through 12-day regular observations on both ascending and descending orbital passes.