Members Can Post Anonymously On This Site
-
Similar Topics
-
By NASA
NASA’s Jet Propulsion Laboratory used radar data taken by ESA’s Sentinel-1A satellite before and after the 2015 eruption of the Calbuco volcano in Chile to create this inter-ferogram showing land deformation. The color bands west of the volcano indicate land sinking. NISAR will produce similar images.ESA/NASA/JPL-Caltech A SAR image — like ones NISAR will produce — shows land cover on Mount Okmok on Alaska’s Umnak Island . Created with data taken in August 2011 by NASA’s UAVSAR instrument, it is an example of polarimetry, which measures return waves’ orientation relative to that of transmitted signals.NASA/JPL-Caltech Data from NASA’s Magellan spacecraft, which launched in 1989, was used to create this image of Crater Isabella, a 108-mile-wide (175-kilometer-wide) impact crater on Venus’ surface. NISAR will use the same basic SAR principles to measure properties and characteristics of Earth’s solid surfaces.NASA/JPL-Caltech Set to launch within a few months, NISAR will use a technique called synthetic aperture radar to produce incredibly detailed maps of surface change on our planet.
When NASA and the Indian Space Research Organization’s (ISRO) new Earth satellite NISAR (NASA-ISRO Synthetic Aperture Radar) launches in coming months, it will capture images of Earth’s surface so detailed they will show how much small plots of land and ice are moving, down to fractions of an inch. Imaging nearly all of Earth’s solid surfaces twice every 12 days, it will see the flex of Earth’s crust before and after natural disasters such as earthquakes; it will monitor the motion of glaciers and ice sheets; and it will track ecosystem changes, including forest growth and deforestation.
The mission’s extraordinary capabilities come from the technique noted in its name: synthetic aperture radar, or SAR. Pioneered by NASA for use in space, SAR combines multiple measurements, taken as a radar flies overhead, to sharpen the scene below. It works like conventional radar, which uses microwaves to detect distant surfaces and objects, but steps up the data processing to reveal properties and characteristics at high resolution.
To get such detail without SAR, radar satellites would need antennas too enormous to launch, much less operate. At 39 feet (12 meters) wide when deployed, NISAR’s radar antenna reflector is as wide as a city bus is long. Yet it would have to be 12 miles (19 kilometers) in diameter for the mission’s L-band instrument, using traditional radar techniques, to image pixels of Earth down to 30 feet (10 meters) across.
Synthetic aperture radar “allows us to refine things very accurately,” said Charles Elachi, who led NASA spaceborne SAR missions before serving as director of NASA’s Jet Propulsion Laboratory in Southern California from 2001 to 2016. “The NISAR mission will open a whole new realm to learn about our planet as a dynamic system.”
Data from NASA’s Magellan spacecraft, which launched in 1989, was used to create this image of Crater Isabella, a 108-mile-wide (175-kilometer-wide) impact crater on Venus’ surface. NISAR will use the same basic SAR principles to measure properties and characteristics of Earth’s solid surfaces.NASA/JPL-Caltech How SAR Works
Elachi arrived at JPL in 1971 after graduating from Caltech, joining a group of engineers developing a radar to study Venus’ surface. Then, as now, radar’s allure was simple: It could collect measurements day and night and see through clouds. The team’s work led to the Magellan mission to Venus in 1989 and several NASA space shuttle radar missions.
An orbiting radar operates on the same principles as one tracking planes at an airport. The spaceborne antenna emits microwave pulses toward Earth. When the pulses hit something — a volcanic cone, for example — they scatter. The antenna receives those signals that echo back to the instrument, which measures their strength, change in frequency, how long they took to return, and if they bounced off of multiple surfaces, such as buildings.
This information can help detect the presence of an object or surface, its distance away, and its speed, but the resolution is too low to generate a clear picture. First conceived at Goodyear Aircraft Corp. in 1952, SAR addresses that issue.
“It’s a technique to create high-resolution images from a low-resolution system,” said Paul Rosen, NISAR’s project scientist at JPL.
As the radar travels, its antenna continuously transmits microwaves and receives echoes from the surface. Because the instrument is moving relative to Earth, there are slight changes in frequency in the return signals. Called the Doppler shift, it’s the same effect that causes a siren’s pitch to rise as a fire engine approaches then fall as it departs.
Computer processing of those signals is like a camera lens redirecting and focusing light to produce a sharp photograph. With SAR, the spacecraft’s path forms the “lens,” and the processing adjusts for the Doppler shifts, allowing the echoes to be aggregated into a single, focused image.
Using SAR
One type of SAR-based visualization is an interferogram, a composite of two images taken at separate times that reveals the differences by measuring the change in the delay of echoes. Though they may look like modern art to the untrained eye, the multicolor concentric bands of interferograms show how far land surfaces have moved: The closer the bands, the greater the motion. Seismologists use these visualizations to measure land deformation from earthquakes.
Another type of SAR analysis, called polarimetry, measures the vertical or horizontal orientation of return waves relative to that of transmitted signals. Waves bouncing off linear structures like buildings tend to return in the same orientation, while those bouncing off irregular features, like tree canopies, return in another orientation. By mapping the differences and the strength of the return signals, researchers can identify an area’s land cover, which is useful for studying deforestation and flooding.
Such analyses are examples of ways NISAR will help researchers better understand processes that affect billions of lives.
“This mission packs in a wide range of science toward a common goal of studying our changing planet and the impacts of natural hazards,” said Deepak Putrevu, co-lead of the ISRO science team at the Space Applications Centre in Ahmedabad, India.
Learn more about NISAR at:
https://nisar.jpl.nasa.gov
News Media Contacts
Andrew Wang / Jane J. Lee
Jet Propulsion Laboratory, Pasadena, Calif.
626-379-6874 / 818-354-0307
andrew.wang@jpl.nasa.gov / jane.j.lee@jpl.nasa.gov
2025-006
Share
Details
Last Updated Jan 21, 2025 Related Terms
NISAR (NASA-ISRO Synthetic Aperture Radar) Earth Earth Science Earth Science Division Jet Propulsion Laboratory Explore More
4 min read NASA Scientists, Engineers Receive Presidential Early Career Awards
Article 4 days ago 6 min read NASA International Space Apps Challenge Announces 2024 Global Winners
Article 5 days ago 3 min read NASA Scientists Find New Human-Caused Shifts in Global Water Cycle
Article 5 days ago Keep Exploring Discover More Topics From NASA
Missions
Humans in Space
Climate Change
Solar System
View the full article
-
By NASA
Learn Home NASA HEAT Student Activity… Heliophysics Overview Learning Resources Science Activation Teams SME Map Opportunities More Science Activation Stories Citizen Science 3 min read
NASA HEAT Student Activity Featured in TIME’s Top 100 Photos of 2024
On April 8, 2024, tens of millions experienced a solar eclipse from Mexico through the United States and into Canada. Astronomers, educators, and organizations had been preparing the public for this grand celestial event. Learning from engagement experiences in 2017, the NASA Heliophysics Education Activation Team (NASA HEAT) promoted an activity called “Eclipse Essentials: Safe and Stylish Solar Viewing Glasses.” The activity was first tested in Albuquerque, New Mexico during the Balloon Fiesta around the October 2023 annular eclipse. Using solar viewing glasses, a paper plate, some drawing and decoration supplies, visitors – minors and adults alike – crowded around the heliophysics tables in the NASA tent. That positive experience led NASA HEAT to modify and perfect the design of their “face shield” activity before offering trainings to numerous educators and outreach personnel in the weeks leading up to the April 2024 engagement events.
Note: The glasses and the art activity are not only useful for solar eclipses. They can be used anytime to safely observe the Sun. While it is never safe to look directly at the sun with unprotected eyes, eclipse glasses are perfect for observing sunspots!
One proof of positive impact can be found at the Myers Elementary School in Grand Blanc, Michigan. Students from two kindergarten classes, escorted outside by their teachers Amy Johnston and Wendy Sheridan, stared toward the sky with their solar viewing glasses using paper plates to watch the solar eclipse on Monday, April 8, 2024. The paper plates, which helped provide additional safety measures to protect their eyes, were attached to solar eclipse glasses and decorated by each student in their classrooms as a project leading up to the big day. A photo of the students was so captivating that multiple media outlets shared it on or shortly after the day of the eclipse.
The global media brand, TIME, selected a photo of these kindergarten students wearing their NASA HEAT-designed solar eclipse-viewing “face shields” during the April 8th solar eclipse as one of “TIME’s Top 100 Photos of 2024”. When sharing about the top 100 photos on Instagram, TIME had this to say:
“Every year the TIME photo department sits down to curate the strongest images that crossed our path over the previous 12 months. And every year, sitting with the images, we find ourselves mulling the ways this collection feels heavier than the last, how the year produced images unlike what we’ve seen before.
But this year something else, a tautness, runs through the collection – the tension of conflict, the anxiety over outcome, anticipation of excitement or in possibility. Somehow, these photographers are able to capture that coiled feeling and hold it within the four walls of a frame. Be it by impeccable timing or intentional framing, they have created a time capsule that feels as if it’s about to be opened.”
NASA HEAT is part of NASA’s Science Activation Portfolio. Learn more about how Science Activation connects NASA science experts, real content, and experiences with community leaders to do science in ways that activate minds and promote deeper understanding of our world and beyond: https://science.nasa.gov/learn
“
Kindergarten students at Myers Elementary School in Grand Blanc, Michigan watched the solar eclipse with special solar viewing glasses on Monday, April 8, 2024. The paper plates, which helped provide additional safety for their eyes, were added on and decorated by each student prior to the big day. Jake May/MLive.com/The Flint Journal Share
Details
Last Updated Jan 13, 2025 Editor NASA Science Editorial Team Related Terms
2024 Solar Eclipse Heliophysics Science Activation Explore More
2 min read First NASA Neurodiversity Network Intern to Present at the American Geophysical Union Annual Conference
Article
3 days ago
2 min read NASA eClips Educator Receives 2024 VAST Science Educator Specialist Award
Article
6 days ago
5 min read NASA’s LEXI Will Provide X-Ray Vision of Earth’s Magnetosphere
Article
1 week ago
Keep Exploring Discover More Topics From NASA
James Webb Space Telescope
Webb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…
Perseverance Rover
This rover and its aerial sidekick were assigned to study the geology of Mars and seek signs of ancient microbial…
Parker Solar Probe
On a mission to “touch the Sun,” NASA’s Parker Solar Probe became the first spacecraft to fly through the corona…
Juno
NASA’s Juno spacecraft entered orbit around Jupiter in 2016, the first explorer to peer below the planet’s dense clouds to…
View the full article
-
By European Space Agency
On 8 January 2025, the ESA/JAXA BepiColombo mission will fly just 295 km above Mercury's surface, with a closest approach scheduled for 06:59 CET (05:59 UTC). It will use this opportunity to photograph Mercury, make unique measurements of the planet’s environment, and fine-tune science instrument operations before the main mission begins. This sixth and final flyby will reduce the spacecraft’s speed and change its direction, readying it for entering orbit around the tiny planet in late 2026.
View the full article
-
By European Space Agency
Video: 00:01:14 At the start of this new year, we look back at close-up pictures and solar flare data recorded by the ESA-led Solar Orbiter mission over the last three years. See and hear for yourself how the number of flares and their intensity increase, a clear sign of the Sun approaching the peak of the 11-year solar cycle.
This video combines ultraviolet images of the Sun's outer atmosphere (the corona, yellow) taken by Solar Orbiter's Extreme Ultraviolet Imager (EUI) instrument, with the size and locations of solar flares (blue circles) as recorded by the Spectrometer/Telescope for Imaging X-rays (STIX) instrument. The accompanying audio is a sonification based on the detected flares and the spacecraft's distance to the Sun.
Solar Orbiter moves on an elliptical path around the Sun, making a close approach to our star every six months. We can see this in the video from the spacecraft's perspective, with the Sun moving closer and farther over the course of each year. In the sonification, this is represented by the low background humming that loudens as the Sun gets closer and becomes quieter as it moves further away. (There are some abrupt shifts in distance visible in the video, as it skips over dates where one or both instruments were inactive or collecting a different type of data.)
The blue circles represent solar flares: bursts of high-energy radiation of which STIX detects the X-rays. Flares are sent out by the Sun when energy stored in 'twisted' magnetic fields (usually above sunspots) is suddenly released. The size of each circle indicates how strong the flare is, with stronger flares sending out more X-rays. We can hear the flares in the metallic clinks in the sonification, where the sharpness of the sound corresponds to how energetic the solar flare is.
Many thanks to Klaus Nielsen (DTU Space / Maple Pools) for making the sonification in this video. If you would like to hear more sonifications and music by this artist, please visit: https://linktr.ee/maplepools
Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA.
View the full article
-
By NASA
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA’s X-59 quiet supersonic research aircraft completed its first maximum afterburner test at Lockheed Martin’s Skunk Works facility in Palmdale, California. This full-power test, during which the engine generates additional thrust, validates the additional power needed for meeting the testing conditions of the aircraft. The X-59 is the centerpiece of NASA’s Quesst mission, which aims to overcome a major barrier to supersonic flight over land by reducing the noise of sonic booms.Lockheed Martin Corporation/Garry Tice NASA completed the first maximum afterburner engine run test on its X-59 quiet supersonic research aircraft on Dec. 12. The ground test, conducted at Lockheed Martin’s Skunk Works facility in Palmdale, California, marks a significant milestone as the X-59 team progresses toward flight.
An afterburner is a component of some jet engines that generates additional thrust. Running the engine, an F414-GE-100, with afterburner will allow the X-59 to meet its supersonic speed requirements. The test demonstrated the engine’s ability to operate within temperature limits and with adequate airflow for flight. It also showed the engine’s ability to operate in sync with the aircraft’s other subsystems.
The X-59 is the centerpiece of NASA’s Quesst mission, which seeks to solve one of the major barriers to supersonic flight over land by making sonic booms quieter. The X-59’s first flight is expected to occur in 2025.
Share
Details
Last Updated Dec 20, 2024 EditorDede DiniusContactMatt Kamletmatthew.r.kamlet@nasa.gov Related Terms
Aeronautics Aeronautics Research Mission Directorate Armstrong Flight Research Center Commercial Supersonic Technology Integrated Aviation Systems Program Low Boom Flight Demonstrator Quesst (X-59) Supersonic Flight Explore More
2 min read NASA, Notre Dame Connect Students to Inspire STEM Careers
Article 4 hours ago 2 min read NASA Flight Rerouting Tool Curbs Delays, Emissions
Article 4 hours ago 3 min read Atmospheric Probe Shows Promise in Test Flight
Article 1 week ago Keep Exploring Discover More Topics From NASA
Armstrong Flight Research Center
Aeronautics
Supersonic Flight
Quesst: The Vehicle
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.