NISAR: The Powerful New Satellite That Will Track Earth’s Secret Shifts – SciTechDaily
The Earth is a dynamic planet constantly evolving. Its surface shifts, its ice melts and freezes, and its forests grow and die. These changes have far-reaching consequences, affecting everything from sea level rise to the climate. Understanding these shifts is essential for preparing for the challenges of the 21st century, but it’s a difficult task. Our planet is a vast and complex place, and these shifts are often subtle and hard to measure. Fortunately, a new tool is about to launch that will give us unprecedented insights into the changes taking place on Earth.
The NASA-ISRO Synthetic Aperture Radar (NISAR) mission is a joint effort between the US space agency NASA and the Indian Space Research Organisation (ISRO). The satellite is scheduled to launch in January 2024, and it will revolutionize our ability to study the Earth’s surface. With its advanced radar instruments, NISAR will provide detailed information on a variety of natural and man-made phenomena, from volcanic eruptions and earthquakes to deforestation and urban sprawl.
“It’s going to be transformative,” says Paul Rosen, NISAR project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “NISAR is going to help us understand how the Earth is changing in a way we’ve never been able to do before.” NISAR is built upon the heritage of previous missions like NASA’s SeaSat and the European Space Agency’s ERS missions, which were designed for ocean and sea ice monitoring, and the spaceborne Synthetic Aperture Radar missions, like the SIR-A and SIR-B missions of the 1980s, which enabled high-resolution topographic mapping and ground deformation studies.
However, NISAR represents a leap forward. Its unique dual-frequency radar, combined with its orbit and measurement techniques, will allow it to see the Earth in new ways. The L-band radar, designed to detect very small changes in the ground, can “see through” dense vegetation and clouds. This is particularly valuable for monitoring forests, glaciers, and the effects of natural disasters like flooding. The S-band radar will provide data for assessing surface changes such as ice sheet deformation and the motion of volcanoes, allowing for analysis of surface changes associated with human activities and their interactions with natural environments.
One of the most exciting applications of NISAR is its ability to monitor Earth’s vast ice sheets. The satellite will measure the movement and thickness of glaciers, providing valuable information on the rate at which these ice masses are melting. “This is critical for understanding how sea level rise is going to affect coastal communities,” explains Rosen. The satellite is able to sense surface deformations to millimeter levels and measure movements as small as half an inch (1 centimeter) per year over areas up to 124 miles (200 kilometers) wide, giving scientists incredible insights into the impacts of melting glaciers.
Another major application is the tracking of earthquakes. NISAR can measure ground motion and detect subtle shifts that occur before, during, and after earthquakes. This information will improve our understanding of earthquake dynamics, enabling scientists to develop more effective early warning systems. Moreover, it will also aid in predicting future earthquake activity and help assess earthquake risk in areas prone to tremors.
The satellite will also track deforestation and agricultural land use, offering a clear picture of how these human activities are affecting the environment. These datasets can inform conservation efforts, help mitigate deforestation, and support efforts to restore natural resources.
The data NISAR collects will be used to study a wide range of environmental phenomena, such as droughts, landslides, and floods, providing insight into these processes and the potential hazards they present.
A unique feature of the NISAR mission is that its data will be publicly available. Scientists worldwide can access this data to conduct their own research, paving the way for groundbreaking discoveries and advancements in various disciplines. This free and open data sharing strategy is a hallmark of NASA’s commitment to scientific transparency and the democratization of data.
To collect the data needed for its research, the satellite will use a technique known as synthetic aperture radar (SAR). SAR works by sending out radio waves and measuring how these waves reflect back from the Earth’s surface. By analyzing these reflections, scientists can obtain information on the ground’s topography, surface properties, and changes over time.
The use of synthetic aperture technology allows NISAR to effectively have a much larger antenna than its actual physical size, enhancing the sharpness of its images and revealing details on Earth’s surface. This capability is invaluable for providing detailed information about the environment and tracking changes on the planet.
The satellite itself is approximately 42 feet long, or about the size of a school bus, and it will travel in a near-polar orbit, circling the Earth every 12 days at a height of 435 miles (700 kilometers). This unique orbit allows NISAR to view nearly every part of Earth’s land surface at least once every 12 days. In addition, its imaging capabilities will allow NISAR to map the Earth’s surface in different lighting conditions, regardless of daylight or weather conditions.
To effectively acquire data during its travels, NISAR relies on sophisticated navigation techniques. This process allows for high-precision navigation, meaning that each SAR image acquired by the satellite will be tied to a specific geographical location. The result of this technology is accurate data and a unique platform for understanding Earth’s diverse features and constant change.
While NISAR is expected to launch in January 2024, the process leading up to its launch involved rigorous development, testing, and collaboration between teams across multiple continents. It’s a testament to the global effort required to address scientific questions and gather information for the well-being of the entire planet.
The launch of NISAR is a major step forward for Earth science research. By revealing Earth’s subtle shifts, NISAR will help scientists better understand the complex processes shaping our planet and build a brighter future for humanity.
