NASA-ISRO SAR (NISAR) is a Low Earth Orbit (LEO) observatory being jointly developed by NASA and ISRO.
The NASA-ISRO Synthetic Aperture Radar (NISAR) mission, a joint endeavour between the National Aeronautics and Space Administration (NASA) and the Indian Space Research Organisation (ISRO)
NISAR represents a breakthrough in radar remote sensing technology. The primary objective of NISAR is to enhance our understanding of natural phenomena, such as earthquakes, volcanoes, landslides, and subsidence, and to monitor the impacts of climate change, among other Earth-related phenomena.
Structure and Features of NISAR satellite
- NISAR’s significance lies in its cutting-edge Synthetic Aperture Radar (SAR) technology. This advanced radar system provides a wealth of data with exceptional accuracy and precision.
- It carries L and S dual band Synthetic Aperture Radar (SAR), which operates with Sweep SAR technique to achieve large swath with high resolution data.
- L-band (1.25 GHz; 24 cm wavelength) polarimetric SAR, to be produced by NASA.
- S-band (3.20 GHz; 9.3 cm wavelength) polarimetric SAR, to be produced by ISRO
REFER: L Band and S Band
3. The SAR payloads mounted on Integrated Radar Instrument Structure (IRIS) and the spacecraft bus are together called an observatory.
1. Dual-frequency Radar: NISAR carries both L-band and S-band radar instruments. The combination of these two radar frequencies allows for a comprehensive view of Earth’s surface, including forests, ice sheets, agriculture, and urban areas. L-band is particularly effective at penetrating vegetation, providing insights into forest health and biomass.
2. Global Coverage: NISAR is designed to capture data on a global scale, enabling scientists to monitor changes in Earth’s surface with unprecedented detail. The satellite’s orbit will provide coverage of Earth’s entire landmass every 12 days.
3. All-Weather Capability: Unlike optical satellites that are hindered by cloud cover and darkness, NISAR’s radar technology can penetrate through clouds and operate day and night. This all-weather capability is crucial for monitoring natural disasters and other phenomena in real-time.
NASA is responsible for providing the L-Band SAR payload system in which the ISRO supplied S-Band SAR payload and both these SAR systems will make use of a large size (about 12m diameter) common unfurl able reflector antenna . In addition, NASA would provide engineering payloads for the mission, including a Payload Data Subsystem, High-rate Science Downlink System, GPS receivers and a Solid State Recorder.
This would be the first dual frequency radar imaging mission in L-Band & S-Band using an advanced Sweep SAR technique to provide L & S band space-borne SAR data with high repeat cycle, high resolution, and larger swath, with capability of full-polar metric and interferometric modes of operation.
The NISAR Observatory will be launched from Satish Dhawan Space Centre(SDSC) SHAR, Sriharikota on the southeast coast of the Indian peninsula, on the GSLV expendable launch vehicle contributed by ISRO. The target launch readiness date is January 2024.
Applications of NISAR satellite:
NISAR studying concepts for a Synthetic Aperture Radar mission is to determine Earth change in three disciplines: ecosystems (vegetation and the carbon cycle), deformation (solid Earth studies), and cryosphere sciences (primarily as related to climatic drivers and effects on sea level. The NISAR satellite has a wide range of applications that will benefit science, research, and society in various ways. Some of its primary applications include:
1. Earthquake and Volcano Monitoring: NISAR’s ability to detect ground deformations with high precision will aid in early warning systems for earthquakes and volcanic eruptions. This could potentially save lives and mitigate damage in affected areas.
2. Climate Change Analysis: NISAR will play a crucial role in tracking the effects of climate change, including the monitoring of ice sheet movement, sea-level rise, and land surface changes. This data is invaluable for understanding the impact of climate change on our planet.
3. Natural Resource Management: The satellite’s ability to assess soil moisture, land subsidence, and agricultural productivity can support better resource management and food security, particularly in regions prone to drought and other environmental challenges.
4. Forestry and Ecosystem Management: NISAR’s L-band radar is instrumental in monitoring forest health, biomass, and changes in vegetation cover, providing valuable data for forest management and biodiversity conservation.
The NISAR satellite represents a milestone in Earth observation technology and an exemplary collaboration between NASA and ISRO. With its state-of-the-art radar technology, global coverage, and myriad applications, NISAR is poised to make invaluable contributions to our knowledge of our planet and our ability to address pressing global challenges. As the satellite continues to capture data and unveil new insights about Earth, it stands as a testament to our ability to use space technology for the betterment of our world.