Context:
India successfully launched the NASA–ISRO Synthetic Aperture Radar (NISAR) satellite from the Satish Dhawan Space Centre, Sriharikota, on July 31, 2025, aboard the GSLV-F16 rocket. This marks the first collaborative Earth observation mission between ISRO and NASA and a major step in global climate and disaster monitoring.
What is NISAR?
- Full Form: NASA–ISRO Synthetic Aperture Radar
- Mission Type: Earth observation using dual-frequency synthetic aperture radar (SAR)
- Mission Duration: 5 years (2025–2030)
- Orbit: Sun-synchronous polar orbit at 747 km altitude
- Launch Vehicle: GSLV-F16 (first GSLV mission into polar orbit)
Mission Objectives
- Monitor minute land and ice surface changes at centimetre-level precision
- Detect and forecast natural disasters including earthquakes, floods, landslides, and volcanic activity
- Track changes in vegetation, wetlands, glaciers, and soil moisture
- Aid sectors like agriculture, infrastructure, water, and climate management
Technological Features
- Dual-frequency SAR capability:
- L-band (NASA) for deeper surface penetration
- S-band (ISRO) for higher-resolution imaging
- 242 km swath width with global revisit every 12 days
- All-weather, 24/7 imaging capability — works through clouds and darkness
- 12-metre deployable reflector antenna enables SweepSAR for wide-area monitoring
Contributions by NASA and ISRO
| Agency | Key Contributions |
|---|---|
| NASA | L-band radar, boom, reflector antenna, GPS, solid-state recorder, and telecom system |
| ISRO | S-band radar, satellite bus (I-3K), launch via GSLV-F16, solar arrays, data and ground systems |
