NISAR Mission

Source: The Hindu

Why in News?

The NASA Jet Propulsion Laboratory (JPL) in California, United States, recently held a send-off ceremony for NISAR (NASA-ISRO Synthetic Aperture Radar).

NISAR will be the first radar of its kind in space to systematically map Earth, using two different radar frequencies (L-band and S-band) to measure changes in our planet's surface less than a centimeter across.

What is the NISAR Mission?

About:

NISAR has been built by space agencies of the US and India under a partnership agreement signed in 2014.

It is expected to be launched in January 2024 from Satish Dhawan Space Centre into a near-polar orbit.

• The satellite will operate for a minimum of three years.
• It is a Low Earth Orbit (LEO) observatory.
• NISAR will map the entire globe in 12 days.

Features

1. It is a 2,800 kilograms satellite consisting of both L-band and S-band Synthetic Aperture Radar (SAR) instruments, which makes it a dual-frequency imaging radar satellite.
2. While NASA has provided the L-band radar, GPS, a high-capacity solid-state recorder to store data, and a payload data subsystem, ISRO (Indian Space Research Organisation) has provided the S-band radar, the Geosynchronous Satellite Launch Vehicle (GSLV) launch system and spacecraft.
3. S band radars operate on a wavelength of 8-15 cm and a frequency of 2-4 GHz. Because of the wavelength and frequency, they are not easily attenuated. This makes them useful for near and far range weather observation.
4. It has a 39-foot stationary antenna reflector, made of a gold-plated wire mesh; the reflector will be used to focus “the radar signals emitted and received by the upward-facing feed on the instrument structure.
5. By using SAR, NISAR will produce high-resolution images. SAR is capable of penetrating clouds and can collect data day and night regardless of the weather conditions.
6. NASA requires the L-band radar for its global science operations for at least three years. Meanwhile, ISRO will utilise the S-band radar for a minimum of five years.

What are the Expected Benefits of NISAR?

• Earth Science: NISAR will provide a wealth of data and information about the Earth's surface changes, natural hazards, and ecosystem disturbances, helping to advance our understanding of Earth system processes and climate change.
• Disaster Management: The mission will provide critical information to help manage natural disasters such as earthquakes, tsunamis, and volcanic eruptions, enabling faster response times and better risk assessments.
• Agriculture: NISAR data will be used to improve agriculture management and food security by providing information about crop growth, soil moisture, and land-use changes.
• Infrastructure Monitoring: The mission will provide data for infrastructure monitoring and management, such as monitoring of oil spills, urbanization, and deforestation.
• Climate Change: NISAR will help to monitor and understand the impacts of climate change on the Earth's land surface, including melting glaciers, sea-level rise, and changes in carbon storage.