NISAR: The satellite that will change how we see Earth

A couple of months from now, the world will witness the launch of a satellite that promises to change the way we understand our planet. This isn’t just any satellite – it’s NISAR, a marvel of scientific innovation that will map our planet in breathtaking detail, all thanks to a special technique.

Designed to provide unparalleled insights into Earth’s dynamic processes, NISAR will monitor changes – from the shifting of tectonic plates to the melting of polar ice caps – with remarkable precision.

Its exceptional capabilities will empower scientists and policymakers to better address pressing global challenges such as climate change, natural disasters, and resource management.

As anticipation builds, the mission stands as a remarkable example of international collaboration, with NASA and ISRO (the Indian Space Research Organization) joining forces to bring this revolutionary technology to life.

The promise of NISAR’s technology

Taking its name and function from Synthetic Aperture Radar (SAR), this satellite will produce a detailed view of Earth’s surface.

The objective? To track the slightest movements on our planet, right down to the scale of an inch (2.5 centimeters).

From the growth of a forest to the motion of glaciers and the flex of Earth’s crust – nothing will escape the watchful eye of NISAR.

Unlike conventional radar, SAR steps up its genius by capturing multiple measurements as it hovers above, thereby refining the scene below.

Think of it as looking at Earth with a super-powered magnifying glass. The beauty of SAR is that it doesn’t need massive antennae to function.

NISAR’s radar antenna reflector, for instance, is 39 feet wide (around 12 meters) – as long as a city bus. Yet, without SAR, it would have to be a staggering 12 miles in diameter to achieve this level of precision.

The journey of SAR

SAR isn’t a new technology. In the early 1970s, a team of engineers at NASA’s Jet Propulsion Laboratory – including Caltech graduate Charles Elachi – developed SAR to study the surface of Venus.

The experts realized the technology’s potential to reveal intricate details of our planet and made it their mission to harness its power.

“The NISAR mission will open a whole new realm to learn about our planet as a dynamic system,” said Elachi.

The advantage of radar lies in its ability to collect data both day and night, undeterred by clouds, which makes it a perfect tool for studying a distant planet.

The JPL venture led to many successful NASA space shuttle radar missions, with each one refining the use of SAR.

SAR: A high-resolution solution

“It’s a technique to create high-resolution images from a low-resolution system,” noted Paul Rosen, NISAR’s project scientist.

SAR works by constantly transmitting microwaves and receiving echoes from Earth’s surface. As the satellite moves, these return signals exhibit slight changes in frequency.

This is where the magic happens. Akin to a camera lens focusing light to produce a photograph, SAR’s processing adjusts for these “shifts” to generate a sharp, focused image.

NISAR will transform Earth observation

Wondering how SAR will revolutionize our understanding of Earth? Imagine a composite of two images that reveals the slightest differences by measuring changes in echo delays – an interferogram.

Picture it as modern art, with each multicolor band signifying the motion of land surfaces. Or envision polarimetry, another SAR technique, which measures the orientation of return waves relative to transmitted signals.

It’s an insightful tool for identifying an area’s land cover and tracking changes such as deforestation and flooding. This will create exceptional opportunities for researchers across the globe.

“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 Space Applications Centre in India.

Developed in partnership with NASA and the Indian Space Research Organisation, NISAR is set to take off from India in March 2025.

The mission will provide us with an unprecedented understanding of changes taking place on Earth’s solid surfaces, including the Antarctic ice sheet.

The anticipation is building as we get ready to see our planet through SAR vision – revealing, insightful, and awe-inspiring.

Information for this article came from a JPL press release.

Image Credit: Credit: ESA/NASA/JPL-Caltech

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–