NISAR Satellite

• The National Aeronautics and Space Administration (NASA) – Indian Space Research Organisation (ISRO) Synthetic Aperture Radar (NISAR) satellite, an Earth observation mission, was launched by ISRO from Sriharikota.

Key Facts About NISAR Satellite

• About: NISAR, jointly developed by ISRO and NASA, is the first satellite mission to use dual-frequency radar (L-band and S-band) from a single platform, with advanced microwave imaging capabilities including polarimetric and interferometric data. 
• Technical Features:
  • Dual-band Synthetic Aperture Radar (SAR):
    • L-band SAR (by NASA): Penetrates forest canopy, ice, and soil, useful for biomass and deformation studies. 
    • S-band SAR (by ISRO): Better for monitoring crops, wetlands, and other surface-level features. 
  • Launch Vehicle: Geosynchronous Satellite Launch Vehicle Mark II (GSLV Mk II) (specifically the GSLV-F16 variant), India’s largest rocket, is an expendable three-stage launch vehicle.
    • The NISAR mission marks the first time ISRO is using a GSLV to place a satellite in sun-synchronous polar orbit. 
  • Mission Life: 5 Years. 
  • Phases: The mission includes four phases– launch, deployment, commissioning, and science operations.
    • The deployment phase extends a 12-meter antenna 9 meters from the satellite, with commissioning in the first 90 days, followed by science operations for the rest of the mission. 
• Mission Objectives and Coverage:  The NISAR mission will provide high-resolution dataevery 12 days to monitor land changes across Earth.
  • It will track ground deformation caused by earthquakes, landslides, and volcanic activity. 
  • Measure forest biomass and carbon stock by observing woody vegetation. 
  • It monitors agricultural patterns such as crop extent and growth cycles, and assesses changes in wetlands driven by seasonal and climatic variations.  
  • Study cryosphere dynamics, including glacier and sea ice melt in the Arctic and Antarctic regions. 
• Significance for India: NISAR marks as a key step in Indo-US space ties, the launch reflects India’s rise as a global science partner or ‘Vishwa Bandhu’.
  • It supports disaster management, agriculture, and climate monitoring. 
  • Furthermore, India has joined the Artemis Accords and collaborated with NASA on human spaceflight, marking a deeper partnership in space exploration. 

What is a Radar Band? 

• About: Electromagnetic radiation with frequencies between about 10 kHz and 100 GHz are referred to as radio frequencies (RF).
  • The RFs are divided into groups that have similar characteristics, called “bands,” such as “S-band,” “L-band,” etc.  
• Common Radar Bands:

Significance:  

• Lower frequency bands (L, S) can penetrate through rain, clouds, vegetation useful for mapping and Earth observation. 
• Higher frequency bands (X, Q, V, W) give sharper images and better resolution, but are more affected by weather and atmospheric conditions.