Revolutionary Collaboration of NASA-ISRO to make NI-SAR
The NASA-ISRO Synthetic Aperture Radar (NISAR) mission is a joint project between NASA and ISRO to co-develop and launch a dual-frequency synthetic aperture radar on an Earth observation satellite. The satellite will be the first radar imaging satellite to use dual frequencies. It will be used for remote sensing to observe and understand natural processes on Earth. For example, its left-facing instruments will study the Antarctic cryosphere. With a cost estimated at US$1.5 billion, NISAR is likely to be the world’s most expensive Earth-imaging satellite.
Overview
The NASA-ISRO Synthetic Aperture Radar, or NISAR satellite, will use advanced radar imaging to map the elevation of Earth’s land and ice masses 4 to 6 times a month at resolutions of 5 to 10 meters. It is designed to observe and measure some of the planet’s most complex natural processes, including ecosystem disturbances, ice-sheet collapse, and natural hazards such as earthquakes, tsunamis, volcanoes and landslides.
Under the terms of the agreement, NASA will provide the mission’s L-band synthetic aperture radar (SAR), a high-rate telecommunication subsystem for scientific data GPS receivers, a solid-state recorder, and a payload data subsystem. ISRO will provide the satellite bus, an S-band synthetic aperture radar, the launch vehicle, and associated launch services.
Societal Relevance of NISAR Mission
As discussed earlier, the NISAR Mission mainly aims to study Earth’s elements from an observing satellite. This space mission will benefit its multiple applications. Discussed below are the same in detail:
Life and Civilisation: NISAR will provide global maps of surface soil moisture every 6 to 12 days at the spatial scale of individual farm fields. This offers unprecedented detail and is vital for monitoring the habitats of plants, animals, and humans.
Damage Mapping: The NISAR satellite mission can provide maps and images of any disturbance which may lead to a natural disaster. Within hours to days of natural disasters like major earthquakes, hurricanes, tsunamis, and landslides, the NISAR satellite will present its observations which will rapidly provide information for rescue operations, economic loss estimates, and the health of the critical infrastructure.
Protecting Water and Oil Spills: Every year, emergency responders work to prevent hundreds of oil and chemical spills from harming people and the environment. Rapid identification of spilled oil in the vast open waters of the oceans and gulf is critical to minimizing damage, and radar remote sensing can provide the necessary information.
Glaciers and Ice Sheet: Observations of the flow of Earth’s ice sheets and glaciers are critical to understanding current and future rates of sea-level rise. Synthetic aperture radar can serve as a ‘radar speed gun’ to provide global maps of ice flow in support of sea-level rise impact assessments.
Marine Hazards: NISAR will provide information to monitor ocean wind, waves, and sea-ice extent that can aid weather forecasting and warn of marine hazards. Its coverage of coastal oceans benefits sea transportation and coastal communities.
Flood Forecasting: Flood forecasting informs downstream communities if a flood is coming and how much flooding to expect. Like a virtual stream gauge, synthetic aperture radar can measure changing water levels in standing vegetation as floodwaters from heavy upriver rains head downstream.
Protecting Forest Resources: NISAR is designed to monitor global forest extent and quality and to provide accurate and timely information on forest volume and products for sustainable development and management of ecosystem goods and services.
SAR Mapping
Synthetic aperture radar (SAR) refers to a technique for producing fine-resolution images from a resolution-limited radar system. It requires that the radar be moving in a straight line, either on an airplane or, as in the case of NISAR, orbiting in space.
The basic principle of any imaging radar is to emit an electromagnetic signal (which travels at the speed of light) toward a surface and record the amount of signal that bounces/echoes back, or “backscatters,” and its time delay. The resulting radar imagery is built up from the strength and time delay of the returned signal, which depends primarily on the roughness and electrical conducting properties of the observed surface and its distance from the orbiting radar.
Upcoming Events
The NASA-ISRO Synthetic Aperture Radar satellite is expected to be launched in 2023, said Shri Jitendra Singh (minister of Science and Technology, India) during an interview on 13th April 2023. He made the remarks during the visit of a US delegation led by Dr. Sethuraman Panchanathan, the director of the National Science Foundation.
