Major Earth Satellite to Track Disasters, Effects of Climate Change


Mar 24, 2021

Technicians and engineers moved the S-SAR into the airlock to the Spacecraft Assembly Facility’s High Bay 1 clean room

The S-band SAR, one of two kinds of radar on the NISAR mission, arrived at JPL on March 19. The next day, technicians and engineers moved the S-SAR into the airlock to the Spacecraft Assembly Facility’s High Bay 1 clean room. The equipment will be unpacked over several days in the clean room.Credits: NASA/JPL-Caltech

Designed to spot potential natural hazards and help researchers measure how melting land ice will affect sea level rise, the NISAR spacecraft marks a big step as it takes shape.

An SUV-size Earth satellite that will be equipped with the largest reflector antenna ever launched by NASA is taking shape in the clean room at the agency’s Jet Propulsion Laboratory in Southern California. Called NISAR, the joint mission between NASA and the Indian Space Research Organization (ISRO) has big goals: By tracking subtle changes in Earth’s surface, it will spot warning signs of imminent volcanic eruptions, help to monitor groundwater supplies, track the melt rate of ice sheets tied to sea level rise, and observe shifts in the distribution of vegetation around the world. Monitoring these kinds of changes in the planet’s surface over nearly the entire globe hasn’t been done before with the high resolution in space and time that NISAR will deliver.

The spacecraft will use two kinds of synthetic aperture radar (SAR) to measure changes in Earth’s surface, hence the name NISAR, which is short for NASA-ISRO SAR. The satellite will use a wire mesh radar reflector antenna nearly 40 feet (12 meters) in diameter at the end of a 30-foot-long (9-meter-long) boom to send and receive radar signals to and from Earth’s surface. The concept is similar to how weather radars bounce signals off of raindrops to track storms. animation shows how the NISAR spacecraft will deploy its radar reflector antenna after launch. Nearly 40 feet (12 meters) in diameter, the reflector will sit at the end of a 30-foot-long (9-meter-long) boom, sending and receiving radar signals to and from Earth’s surfaceCredits: NASA/JPL-Caltech

NISAR will detect movements of the planet’s surface as small as 0.4 inches (a centimeter) over areas about the size of half a tennis court. Launching no earlier than 2022, the satellite will scan the entire globe every 12 days over the course of its three-year primary mission, imaging the Earth’s land, ice sheets, and sea ice on every orbit.

Activities such as drawing drinking water from an underground aquifer can leave signs on the surface: Take out too much water, and the ground begins to sink. The movement of magma under the surface before a volcanic eruption can cause the ground to move as well. NISAR will provide high-resolution time-lapse radar imagery of such shifts.

NISAR mission members from ISRO and JPL

On March 20, NISAR mission members from ISRO and JPL moved the S-band SAR, one of two kinds of radar that will be used on the project, into the airlock to the Spacecraft Assembly Facility’s High Bay 1 clean room. Once the radar moves into the clean room, it will be unpacked over several days.Credits: NASA/JPL-Caltech

An All-Weather Satellite

On March 19, NISAR’s assembly, test, and launch team at JPL received a key piece of equipment – the S-band SAR – from its partner in India. Together with the L-band SAR provided by JPL, the two radars serve as the beating heart of the mission. The “S” and “L” denote the wavelength of their signal, with “S” at about 4 inches (10 centimeters) and “L” around 10 inches (25 centimeters). Both can see through objects like clouds and the leaves of a forest canopy that obstruct other types of instruments, although L-band SAR can penetrate further into dense vegetation than S-band. This ability will enable the mission to track changes in Earth’s surface day or night, rain or shine.

“NISAR is an all-weather satellite that’s going to give us an unprecedented ability to look at how Earth’s surface is changing,” said Paul Rosen, NISAR project scientist at JPL. “It’ll be especially important for scientists who have been waiting for this kind of measurement reliability and consistency to really understand what drives Earth’s natural systems – and for people who deal with natural hazards and disasters like volcanoes or landslides.”

Both radars work by bouncing microwave signals off of the planet’s surface and recording how long the signals take to return to the satellite as well as their strength when they return. The larger the antenna sending and receiving the signals, the higher the spatial resolution of the data. If researchers wanted to see something about 150 feet (45 meters) across with a satellite in low-Earth orbit operating an L-band radar, they’d need an antenna nearly 14,000 feet (4,250 meters) long – the equivalent of about 10 Empire State Buildings stacked on top of each other. Sending something that size into space just isn’t feasible.

Yet NISAR mission planners had ambitions to track surface changes at an even higher resolution – down to around 20 feet (6 meters) – requiring an even longer antenna. This is why the project uses SAR technology. As the satellite orbits Earth, engineers can take a sequence of radar measurements from a shorter antenna and combine them to simulate a much larger antenna, giving them the resolution that they need. And by using two wavelengths with complementary capabilities – S-SAR is better able to detect crop types and how rough a surface is, while L-SAR is better able to estimate the amount of vegetation in heavily forested areas – researchers can get a more detailed picture of Earth’s surface.

Testing, Testing…

So the arrival of the S-band system marked a big occasion for the mission. The equipment was delivered to the JPL Spacecraft Assembly Facility’s High Bay 1 clean room – the same room where probes used to explore the solar system, like Galileo, Cassini, and the twin Voyager spacecraft, were built – to be unboxed over the course of several days. “The team is very excited to get their hands on the S-band SAR,” said Pamela Hoffman, NISAR deputy payload manager at JPL. “We had expected it to arrive in late spring or early summer of last year, but COVID impacted progress at both ISRO and NASA. We are eager to begin integrating ISRO’s S-SAR electronics with JPL’s L-SAR system.”

Engineers and technicians from JPL and ISRO will spend the next couple of weeks performing a health check on the radar before confirming that the L-band and S-band SARs work together as intended. Then they’ll integrate the S-SAR into part of the satellite structure. Another round of tests will follow to make sure everything is operating as it should.

“NISAR will really open up the range of questions that researchers can answer and help resource managers monitor areas of concern,” said Rosen. “There’s a lot of excitement surrounding NISAR, and I can’t wait to see it fly.”

More About the Mission

NISAR is a joint Earth-observing mission between NASA and ISRO. JPL, which is managed for NASA by Caltech in Pasadena, leads the U.S. component of the project as well as providing the mission’s L-band SAR. NASA is also providing the radar reflector antenna, the deployable boom, a high-rate communication subsystem for science data, GPS receivers, a solid-state recorder, and payload data subsystem. ISRO is providing the spacecraft bus, the S-band SAR, the launch vehicle, and associated launch services and satellite mission operations.

To learn more about the mission, visit:

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Steve Case
March 25, 2021 3:01 am

 “…track the melt rate of ice sheets tied to sea level rise…”

The ice sheets aren’t melting because in Greenland and Antarctica it’s well below freezing nearly everywhere nearly all the time. They might be losing ice due to an imbalance between snow fall and calving of icebergs, but they’re not melting. This is one of several big lies that gets repeated over and over and over again.

Reply to  Steve Case
March 25, 2021 3:54 am
Reply to  griff
March 25, 2021 5:50 am

Greenland’s net melt/gain has more to do with how much snow falls during the cold months. Some years a lot of snow falls and some years not so much. It has to do with blocking patterns that set up in the Arctic during winter, which has a lot to do with ocean temperatures, which has a lot to do with El Niño/La Niña conditions, which has a lot to do with the decadal and multi-decadal cycles, which has a lot to do with solar cycles.. and the list goes on. It’s a chaotic system that plays out over centuries and millenia.

And by the way, here is the global JRA-55 2m temperature trend for the past 15 months. Notice a trend?

Reply to  griff
March 25, 2021 7:27 am

griff ……. there but for the Grace of God go I.

How’s that polar sea ice going griff? Don’t be forgetting Antarctica now there’s even more back radiation from caaairbon beating down on it.

You’ve been a bit slow on your reporting recently.

Steve Case
Reply to  griff
March 25, 2021 7:33 am

There is summer surface melting, there has always been summer melting, those blue crystal clear rivers disappearing down the moulins have always done so. And the claim that the water lubricates the flow of the ice sheet is bullshit because that’ s how ice skates work. Drainage water from the surface isn’t going to make them flow any faster. And the claims that radar detects large cavities of liquid water well below the surface, they’ve been there all along as well. And the “warm” water eroding the ice sheet at the grounding line – if that’s what’s going on – that’s been going on right along too.

If you have a source that definitively says that any those things constitute a new phenomenon please provide the source.

Having said all that, sea level IS rising, and the water has to be coming from someplace and the ice sheets calving more ice into the sea than snow that fell years decades or even centuries ago is a good bet for what’s going on. Global rise in temperature of one degree over the last 170 years has precious little to do with it.

Thanks for the reply

Clyde Spencer
Reply to  Steve Case
March 25, 2021 12:40 pm

The surface melt-water only makes it to the base of glaciers near the terminus where the ice is thin. Because ice more than about 200 feet in thickness flows by plastic deformation, cracks tend to heal, below the transition to plastic flow. Warm water may widen and deepen cracks, but it isn’t going to make it to depths much greater than the transition depth. When water is found at the base of very thick ice, it is the result of geothermal heat melting the ice immediately above the bedrock. It is that water that can make a difference in down-slope rate of movement because it is under compression with no way to escape, except maybe down-slope.

The US Army drove tunnels into the Greenland glacier near Camp Tuto about 1957. The ice was thick enough that plastic deformation was monitored for a decade after that, before closing Camp Tuto. After driving the tunnel in about 1,500 feet, a decision was made to drive a shaft upward for a fresh air supply. However, once the shaft got close enough to the surface to see blue light, the miners could hear rushing melt-water. They prudently decided to quit so that they didn’t get flushed out. It is important to note that the melt-water stream was flowing well above the base of the glacier, even near the terminus.

Reply to  Steve Case
March 25, 2021 12:44 pm

They might be losing ice due to an imbalance between snow fall and calving of icebergs, but they’re not melting. This is one of several big lies that gets repeated over and over and over again.


those blue crystal clear rivers disappearing down the moulins have always done so.


I really hate to have to agree with Graft but he did make a valid point. There is a clear contradiction between your two statements.

Like most of the climate scare mongering the silly claims about GIS disappearing are total fallacy but there is currently some melting. Since Greenlands bedrock is concaved, the ice is not going to slide into the sea, no matter how much you “lubricate” it.

Steve Case
Reply to  Greg
March 25, 2021 1:53 pm

Greg, what’s going on two is separate issues Surface melting and loss of ice due to calving of glaciers. Of the two, loss of ice due to calving of glaciers is the elephant in the living room. Loss of ice measured by those two GRACE satellites is implied by the press as caused by the surface ice melt and they show us images of blue water disappearing down moulins when it’s really calving ice bergs.

It’s the mountains of ice, some as big as Manhattan, calving into the sea that does the heavy lifting and that isn’t a function of temperature. Although the press also wants you to believe that it is.

Whatever is claimed to be causing ice loss in the polar ice caps and running up sea level today, has been going on for a long time. There’s nothing new. Sea level has been rising at nearly the same rate as it did in the early 19th century when the first tide gauges began keeping records.

Reply to  griff
March 25, 2021 8:16 am

Yes there is some melting, Always has but there is new snow to replace it every year.

There is nothing to worry about.

Reply to  griff
March 25, 2021 1:10 pm
Reply to  griff
March 25, 2021 10:55 pm

Greenland ice mass since 1900

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Greenland Ice Area last 8000+ years

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Greenland SMB less in the 1930s.

comment image

Reply to  griff
March 25, 2021 10:56 pm

Greenland temps from IPCC.. warmer in the 1930s,40s

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Greenland December temperatures

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Roger Taguchi
Reply to  Steve Case
March 25, 2021 4:13 am
Trying to Play Nice
Reply to  Roger Taguchi
March 25, 2021 5:19 am

So you’re saying that on this spot the snow melted because of high air temperatures, but all around it the snow didn’t melt. It doesn’t appear that there is any melt water draining into the hole either. So there is a micro-climate 150m long where the temperature is much higher than surrounding areas?

Alan Robertson
Reply to  Trying to Play Nice
March 25, 2021 6:08 am

One might notice the black soot, settled out on the bottom of the pool.
Might someone think that soot on snow plays a wee bit of a melt effect?

Steve Case
Reply to  Roger Taguchi
March 25, 2021 7:49 am

Hi Roger, hop in Dr. Brown’s Delorean and tootle on back a couple of centuries to see if there were rivers on Greenland’s surface back then.

See my post above.

Reply to  Roger Taguchi
March 25, 2021 8:20 am

Annnnd your point is what?

You show a photo with no link and no science commentary.

It is worth just 21 words.

Roger Taguchi
Reply to  Sunsettommy
March 25, 2021 12:04 pm

Steve Case said: “but they’re not melting”
What better way to refute such a statement by showing GREENLAND MELTWATER?

Clyde Spencer
Reply to  Roger Taguchi
March 25, 2021 12:58 pm

The implication of the term “melting,” in context, is that the ice sheet is in decline. What you are illustrating is a phenomena related to processes that operate every Summer at lower elevations, and then freeze up again in the Winter.

I get the strong impression that you are grasping to find rationalizations to support your belief system, and you have a poor understanding of the things you are talking about. You and griff have a lot in common, along with the other alarmists.

Roger Taguchi
Reply to  Clyde Spencer
March 25, 2021 4:17 pm

The ice in Greenland is melting. There is measurable GIA rebound using high precission GPS measurement. As the ice melts, the ground rises.

Clyde Spencer
Reply to  Roger Taguchi
March 25, 2021 5:03 pm

It is statements such as this that leads me to believe that you don’t really understand what you are reading, and that you don’t have the background to understand it in context.

Isostatic rebound is going on all over the high northern latitudes. It is a slow response to the rapid loss of ice 20,000 years ago. It alone is not an indication of recent loss. There is some loss going on recently, but it is not very much.

Considering that the Arctic is warming, it would be surprising if there wasn’t some loss of ice on the margins of Greenland. However, the magnitude and rate of loss is such that it will be thousands of years, assuming the climate doesn’t change by then, before Greenland looks like it did during the Eemian. David Middleton addressed this quite awhile back.

Reply to  Roger Taguchi
March 26, 2021 3:04 am


But you knew that didn’t you, cockroach.

Reply to  Sunsettommy
March 25, 2021 12:51 pm

Don’t you understand how climate science works? You want proof and well reasoned arguments? Come on man !!

Reply to  Roger Taguchi
March 25, 2021 12:47 pm

45 meters deep . Jeez, that sounds impressive until you check on the size of Greenland. 😉

Clyde Spencer
Reply to  Roger Taguchi
March 25, 2021 12:52 pm

And your point is? Typically, in the Summer at lower elevations, there will be a mushy firn a few feet thick, that may support an arctic fox, but would be difficult for a human to traverse without skis or snow shoes. I know from personal experience that a large cobble tossed out onto it will sink a couple of feet. It has a high water content and the water will tend to drain to open areas, such as tensional cracks. The collected warm water may melt the surrounding ice, widening the crack(s). However, there is a very good reason why the water shown is a static pool only about 150 feet deep, and has not completely disappeared.

Reply to  Roger Taguchi
March 25, 2021 11:00 pm

Ignorance run in your veins doesn’t it, rogered,

that’s from all the intravenous Klimate Kool-aide you have been using.

Greenland ice mass since 1900

comment image
Greenland Ice Area last 8000+ years

comment image
Greenland SMB less in the 1930s.

comment image

Ron Long
March 25, 2021 3:29 am

So they’re hoping the NISAR satellite can measure a vertical change of 1 cm over a pixel size of 6 m? I’m skeptical of this precision, however, if they succeed they will encounter what author Peter Wylie wrote a book about in 1971, “The Dynamic Earth”. How’s that song go? “I feel the earth move under my feet…”?

Reply to  Ron Long
March 25, 2021 3:45 am

Carole King….

March 25, 2021 3:44 am

 imaging the Earth’s land, ice sheets, and sea ice on every orbit.

And then what, comparing them to 1979?

Three years is a snapshot

paul courtney
Reply to  fretslider
March 25, 2021 11:09 am

Mr. slider: Then they will compare them to yesterday’s images, find a warming trend, and….it’s settled.
Did we ever hear more about the co2 sat. that showed CO2 not as well mixed as they thought?

paul courtney
Reply to  paul courtney
March 25, 2021 11:10 am

I swear I did not see fred and Tom below before I posted. Good on yas!

March 25, 2021 3:47 am

I wonder if this one will “go dark” like the CO2 satellite appears to have done 😉

Tom Abbott
Reply to  fred250
March 25, 2021 8:55 am

Whatever happened to those CO2-measuring satellites?

NASA doesn’t seem too keen to discuss the findings of these satellites.

The satellite findings must not fit the Human-caused Climate Change narrative. So we get a news blackout.

Clyde Spencer
Reply to  Tom Abbott
March 25, 2021 1:04 pm

I haven’t seen anything about the Chinese CO2 monitoring satellite either.

An instrument similar to the OCO-2 was installed on the Space Station, and it has been crickets with respect to that also!

Clyde Spencer
Reply to  Tom Abbott
March 25, 2021 5:07 pm

I actually found something relatively recent about OCO-2 and OCO-3:

March 25, 2021 4:01 am

todays Bom in Aus has a 700km+ sat pic of our flooded nsw areas
we really need more of this stuff whizzing round spying?

March 25, 2021 4:25 am

“NISAR will detect movements of the planet’s surface as small as 0.4 inches (a centimeter) over areas about the size of half a tennis court.”
So they will be able to see the effect of wave motion on the sea ice? Of course the wave motion will be larger than that. A true momentary snapshot.

Curious George
Reply to  lee
March 25, 2021 7:57 am

They promise to detect centimeters, sea level guys work with millimeters. How they smooth the ocean surface is beyond me.

Rainer Bensch
Reply to  lee
March 26, 2021 4:37 am

How do they compensate for the effects the moon’s gravity has on the land? That will likely be in the same ballpark.

March 25, 2021 5:30 am

This will be launched just in time to watch what happens to a cooling Earth over the next decade or two. Do they really want to put this thing up?

Reply to  rbabcock
March 25, 2021 7:22 am

Of course they do because the nitwits/criminals at the Guardian and the BBC and CNN and Penn State et al., can say take no notice of the fact that you walked out of your door and then hastily went back to get your parka. Scientific experts have used satellites to show that the planet is blah blah blah-ing ……………………..

…. and all the children are going to die, and so on and so forth.

March 25, 2021 5:32 am

Why were we waiting till 2022 to measure micro surface movement on Earth by satellite? Much more useful than hundreds of military or commercial TV satellites….
Californians, Japanese etc. should rejoice: more chance of a solid warning before Mother Nature ‘shivers” again.

Bruce Cobb
March 25, 2021 6:34 am

Maybe they can use it to spot space aliens, like an early warning system. That’d be cool. Otherwise, I have my doubts about not only the value, but also serious misgivings about the way any of this might be mis-used by Climatists and the Alarmstream media.

John in Oz
Reply to  Bruce Cobb
March 25, 2021 3:28 pm

Perhaps the Oz (current) opposition can use this.

Opposition science spokesman Richard Marles says Australian ingenuity could help discover “life beyond earth” within a decade but warns the nation still risks falling behind the technological revolution sweeping the globe.

Joel O'Bryan
March 25, 2021 6:52 am

While this seems novel to these science writers, let me assure WUWT readers that various military satellites from various countries have long employed coherent waveform, synthetic aperture radar techniques for hi-res imaging and ground mapping for some time, including using mongo-big antennas.

I also am old enough to remember 2014 when NASA’s OCO-2 launched to much fanfare from climate fanatics who were certain it would show them exactly what they expected, confirming super-computer simulations of global CO2 fluxes and the Bern model used in all the IPCC reports on CO2 sources and sinks. In 2017, in a series of Sci Mag papers, OCO-2’s hard data blew away many of the long-held falsehoods.
But since then on OCO-2??? … (cue the sound of crickets)

Gordon A. Dressler
March 25, 2021 6:56 am

From the third paragraph of the above article attributed to NASA, with corrections by me: “By tracking subtle changes in Earth’s surface, it will spot warning signs of imminent volcanic eruptions, help to monitor groundwater supplies, track the melt rate increase in size of ice sheets tied to sea level rise . . .”

See the WUWT article just put up: “Greenland And Iceland Mean Winter Temperatures Continue Cooling Since Start Of The Century” (link )

March 25, 2021 7:11 am

Will it see this? Let’s do a test.

S_stddev_timeseries.png (1050×840) (

Coach Springer
March 25, 2021 7:30 am

“Track the effects of climate change”? It’s not like they have an identifier for what is climate change and further what part of it is “(white) man-caused”.So they’re tracking nature and assuming everything that happens is man-caused.

Curious George
Reply to  Coach Springer
March 25, 2021 8:01 am

Climate change: spring, summer, fall, winter.

Clyde Spencer
Reply to  Curious George
March 25, 2021 1:09 pm

As narrated by Princess Summer-Fall-Winter-Spring, with cameo appearances by Howdy Doody and Buffalo Bob.

H. D. Hoese
March 25, 2021 7:38 am

Long dead oceanographers were worried a half century ago when these started that satellites could not replace actual in situ measurements. They do cut down seasickness.

March 25, 2021 9:17 am

Good for scientific use bad for public when politicians and regulators get their hands on the information and use it to further political agendas. The predetermined goal is evident because the have announced it.

Robert of Texas
March 25, 2021 10:54 am

So…land movement and volcanoes are caused by climate change now? I wonder if they also are migrating north due to hotter temperatures? That or they go extinct. (<– Yes, sarcasm)

And sea level rise is now completely credited to climate change? I got news for them – land subsidence accounts for a lot of the so-called sea level rise. And if the land under the oceans is rising, so does the ocean. They sure seem to presume a lot.

Meanwhile all those islands in the Pacific that were going to disappear…they are still here! (I wonder if they too started migrating north?)

March 25, 2021 12:31 pm

over areas about the size of half a tennis court.

I don’t play tennis, can we have that in football fields please ?

Or failing all else, something really stupid like internationally recognised units of measurement.

BTW it is clearly not “SUV sized” because the crate it came in is only 1.5m high !!

Why do these half wit media studies types always thing the public is too stupid to know what ten or twenty yards/metres looks like?

March 25, 2021 1:45 pm

I hope that the satellite’s precision and accuracy estimates are better than NASA’s claims for the Grace satellites. When Grace was commissioned they claimed that they could detect changes in glacier mass of a few cm of water equivalent. During the satellites’ first decade Lake Mead, a huge lake in Nevada, dropped about 15 meters but they could barely detect the mass loss. I wrote to the Principal Investigator, asking why the satellites were performing so poorly. Never heard back.

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