The next addition to NASA’s fleet of Earth Science orbiters is launching in 2024 and will represent a monumental leap forward in how we monitor our changing planet. The NISAR mission is a collaboration between NASA and the Indian Space Research Organisation that’s designed to monitor and study tiny movements of Earth’s surface from events like natural disasters and climate change.

Read on to find out how NISAR is pushing the boundaries of Earth science from space. Plus, learn how you can bring science and engineering from the mission to your students.

How NISAR Works

NISAR is among the most advanced radar systems on an Earth science mission to date due to its supersized antenna reflector, use of synthetic aperture radar, and ability to observe Earth in two different radar frequencies simultaneously.

Hear mission experts describe how the NISAR satellite will track our changing Earth in fine detail. Credit: NASA/JPL-Caltech

Extending above the spacecraft like a giant catcher's mitt, NISAR’s antenna reflector is 39 feet (12 meters) wide – the largest ever launched as part of a NASA Earth-observing mission. This antenna creates an observational window, or swath, of the surface beneath the spacecraft that is 150 miles (242 kilometers) wide. The swath size is determined by the radar wavelength and antenna size, which is important because there is a direct relationship between antenna size and the resolution of images and data that can be captured by NISAR.

NISAR's antenna reflector extends above the spacecraft like a catcher's mitt and is engineered to help the mission get an unprecedented view of Earth's surface. Credit: NASA/JPL-Caltech | + Expand image

We typically want the best resolution possible, but we’re limited by the size of the antenna we can build and deploy in space. Conventionally, the resolution on a satellite is a function of the wavelength it uses and the size of the antenna. The larger the wavelength, the bigger the antenna needs to be to get quality images. At typical radar wavelengths, with a 12 meter diameter reflector, the best achievable resolution would be as coarse as 10s of kilometers, which is not very useful for observing features on Earth at the human scale.

This diagram shows how synthetic aperature radar works by sending multiple radar pulses to an area on the ground from an antenna passing overhead. Credit: NASA | + Expand image

This is why NISAR utilizes an approach called synthetic aperture radar, or SAR, to synthetically magnify the resolution achievable from the antenna. With SAR, the spacecraft sends multiple signals, or pulses, to an area as it flies overhead. Each signal gets reflected back to the spacecraft, which is meticulously designed to “catch” the reflected signals thanks to its position and velocity. Each signal in the sequence is then focused into a single high-resolution image, creating an effect as if the spacecraft is using a much larger antenna.

Radar uses radio wavelengths, which are longer than those of visible light, allowing us to see through clouds and sometimes even tree coverage to the ground below, depending on the frequency of the radio waves. We’re also able to interpret a lot of information about the surface from the way the signal returns back to the orbiter. This is because NISAR will measure the amount of scatter, or dispersion, of the signal as compared to when it was originally transmitted.

For example, a rigid, sharp angled building will bounce the signal back to the receiver differently than a leafy tree. Different radio frequencies are better used for different surfaces because they are influenced by the type of surface being analyzed. To this end, NISAR is the first mission to use two different radar frequencies simultaneously. The L-Band can be used to monitor heavier vegetation and landscapes while the S-Band is better tuned for lighter vegetation and crop growth. The two wavelengths in general extend the range of sensitivity of the measurement to smaller and larger changes.

This combination of tools and features will allow NISAR to construct global maps of changes in the position of any given pixel at a scale of just centimeters as well as subtle changes in reflectivity due to land cover changes on all land and ice surfaces twice every 12 days. The resolution combined with repetition will allow scientists to monitor the changes taking place on our planet in a matter of days more comprehensively than ever before.

This satellite image of New Orleans is overlaid with synthetic aperature radar data from the UAVSAR instrument to show the rate at which the land was sinking in a section of New Orleans from June 2009 to July 2012. Credit: NASA/JPL-Caltech, Esri | › Learn more

What the NISAR Mission Will Show Us

Because of the massive amount of data produced by NISAR, we’ll be able to closely monitor the impacts of environmental events including earthquakes, landslides, and ice-sheet collapses. Data from NISAR could even be used to assess the risk of natural hazards.

Scientists can use NISAR to monitor tiny movements in Earth’s surface in areas prone to volcanic eruptions or landslides. These measurements are constructed using what’s called an interferogram, which looks at how the maps generated for each pass of the spacecraft have changed over time. For example, we could see immediate changes to the topography after an earthquake with an interferogram made from images NISAR collected shortly before and soon after the event.

Using interferometry, as shown in this diagram, NISAR can capture changes or deformation in land surfaces, such as after an earthquake. | + Expand image

By tracking and recording these events and other movements on the surface leading up to natural disasters, it may be possible to identify warning signs that can improve detection and disaster response.

The first two images in this series were captured by the UAVSAR instrument during two separate passes over California's San Andreas Fault about a year apart. The two images were then combined to create the third image, which an interferogram that shows how the surface changed between the two passes of the instrument. Credit: NASA/JPL-Caltech | + Expand image

And NISAR isn’t just limited to studying the solid Earth. As missions prior have done, it will also be able to generate maps of polar ice sheets over time and detect changes in permafrost based on the regional movement of the soil below. These measurements will give climate scientists a clear picture of how much the ice is moving and deforming due to climate change and where it is thawing as the ground warms.

Additionally, NISAR can track land usage, deforestation, sea levels, and crustal deformation, informing scientists about the impacts of environmental and climate change on Earth.

Follow Along With NISAR

NISAR is scheduled to launch in 2024 from the Satish Dhawan Space Centre in Sriharikota, India, and will enter a polar orbit 460 miles (747 kilometers) above Earth. For the first 90 days after launch, the spacecraft will undergo checks and commissioning before beginning scientific observations for a primary mission designed to last three years.

Science from the mission will be downlinked to both NASA and ISRO ground stations below with data and the tools to process it freely available for download and use to all professional and citizen scientists.

Visit NASA’s NISAR mission page for the latest updates about the mission.

Teach Earth Science With NISAR

With the launch of NISAR, we will be better able to monitor and mitigate natural disasters and understand the effects of climate change. Bring the fleet of NASA Earth Science missions to your classroom with the following lessons and activities:

Lessons

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  Math Problem

  Orbit Observation: A ‘Pi in the Sky’ Math Challenge

  In this illustrated math problem, students use the mathematical constant pi to figure out how much data the NISAR spacecraft collects every day.

  Subject Math

  Grades 7-12

  Time Less than 30 mins

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  Lesson

  Modeling Crustal Folds

  Students use playdough to model how Earth’s crust is bent and folded by tectonic plates over geologic time.

  Subject Science

  Grades 6-12

  Time 30-60 mins

• 
  Lesson

  Making Topographic Maps

  Students draw and interpret topographic maps while learning about technology used to map Earth's surface, the seafloor, and other worlds.

  Subject Science

  Grades 6-12

  Time 1-2 hrs

• 
  Lesson

  Using Light to Study Planets

  Students build a spectrometer using basic materials as a model for how NASA uses spectroscopy to determine the nature of elements found on Earth and other planets.

  Subject Science

  Grades 6-11

  Time 2+ hrs

• 
  Lesson

  Modeling the Water Budget

  Students use a spreadsheet model to understand droughts and the movement of water in the water cycle.

  Subject Science

  Grades 5-8

  Time 30-60 mins

• 
  Lesson

  Fired Up Over Math: Studying Wildfires from Space

  Students learn how scientists assess wildfires using remote sensing and solve related math problems, appropriate for various grade levels.

  Subject Math

  Grades 3-12

  Time 30-60 mins

• 
  Lesson

  Earth Science Data Visualizations – How to Read a Heat Map

  Students learn to read, interpret and compare “heat map” representations of Earth science data.

  Subject Science

  Grades 4-12

  Time 30-60 mins

• 
  Lesson

  Lessons in Sea-Level Rise

  What is sea-level rise and how does it affect us?

  Subject Science

  Grades 5-12

  Time 30-60 mins

• 
  Collection

  Earth Science Lesson Collection

  Discover a collection of standards-aligned STEM lessons all about Earth and climate change.

• 
  Collection

  Climate Change Lesson Collection

  Explore a collection of standards-aligned STEM lessons for students that get them investigating climate change along with NASA.

Student Projects and Activities

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  Collection

  Exploring Earth Activities Collection

  Try these science and engineering projects, watch videos, and explore images all about the planet that we call home.

• 
  Collection

  Climate Change Activities Collection

  Learn about climate change and its impacts with these projects, videos, and slideshows for students.

Articles

• 
  Collection

  Teachable Moments in Climate Change

  Explore this collection of Teachable Moments articles to get a primer on the latest NASA Earth science missions, plus find related education resources you can deploy right away!

Videos

• 
  Collection

  Earth Minute Video Series

  This series of animated white-board videos for students of all ages explains key concepts about Earth science, missions, and climate change.

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  Expert Talk

  Monitoring Earth from Space

  In this educational talk, NASA experts discuss how we build spacecraft to study climate, then answer audience questions.

Explore More

Websites

• NISAR Mission
• NASA Earth
• NASA Climate

Facts & Figures

• NISAR Science Handbook (PDF)

Multimedia

• Interactive: NASA Eyes on Earth
• Images: NASA Earth Observatory
• Gallery: Images of Climate Change
• Infographic: Sea Level Rise

TAGS: K-12 Education, Resources, Earth Science, Climate Change, NISAR

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  ABOUT THE AUTHOR

  Brandon Rodriguez, Educator Professional Development Specialist, NASA-JPL Education Office

  Brandon Rodriguez is the educator professional development specialist at NASA’s Jet Propulsion Laboratory. Outside of promoting STEM education, he enjoys reading philosophy, travel and speaking to your dog like it's a person.