Why in news?
The NASA–ISRO Synthetic Aperture Radar (NISAR) satellite is scheduled for launch on 30 July 2025 from Sriharikota using the GSLV‑F16 launch vehicle. NISAR is the world’s first dual‑frequency Earth observation mission and is a flagship example of U.S.–India space cooperation.
What is NISAR?
- NISAR is an Earth‑observing satellite equipped with both L‑band and S‑band synthetic aperture radar (SAR). This dual‑frequency capability allows it to capture fine‑grained data regardless of weather conditions, time of day or cloud cover.
- It is designed to measure changes in Earth’s surface with millimetre‑level precision, enabling scientists to monitor tectonic shifts, glacier movement, soil moisture and ecosystem dynamics.
Contributions by NASA and ISRO
- NASA: Provides the L‑band radar system, high‑rate communications subsystem, GPS receivers and data processing infrastructure.
- ISRO: Supplies the S‑band radar, the spacecraft bus, the GSLV‑F16 launch vehicle and ground support for mission operations.
Objectives
- Monitor land deformation, earthquakes and landslides by detecting tiny shifts in the Earth’s crust.
- Track glacier and ice‑sheet dynamics to understand sea‑level rise.
- Measure soil moisture and vegetation health to support agriculture and disaster management.
- Collect data on coastal processes, wetlands and forest ecosystems to inform climate change assessments.
Key features
- Dual‑frequency SAR: Uses both L‑band (long wavelength) and S‑band (shorter wavelength) radar to capture complementary datasets.
- Unfurlable antenna: A 12‑metre mesh reflector unfolds in orbit to provide high‑resolution imaging across a wide swath (about 242 km) with a 12‑day revisit cycle.
- High spatial resolution: Detects surface changes smaller than one centimetre.
- All‑weather capability: Operates day and night, penetrating cloud cover and heavy rain.
Significance
- First dual‑frequency radar mission, showcasing advanced technology and international collaboration.
- Enhances disaster response and resource management by providing timely and accurate data.
- Supports the Sustainable Development Goals (SDGs) by improving monitoring of environmental indicators.
- Strengthens Indo‑US strategic ties in the space domain.
NISAR reflects India’s growing stature in space technology and its commitment to collaborative science that benefits humanity.