Speaking of historical satellite imagery, Bill Morris went digging for satellite imagery of what preceded Manicouagan Reservoir before it was created in the 1960s by Quebec’s massive hydro dam projects. But since Landsat first launched in 1973, after the dam was completed, what imagery was there? Answer: CIA spy satellite imagery from 1965—when satellites took pictures on film that was then sent back to Earth—that was declassified in 1996. Read more.
Tag: satellite imagery
China’s GPS Shift and Online Maps
If the road grid in online maps of China doesn’t line up with the aerial/satellite imagery layer, Anastasia Bizyayeva explains in a Medium post earlier this year, it’s because China’s map data uses a different geodetic datum, GCJ-02, rather than WGS-84. “GCJ-02 is based on WGS-84, but with a deliberate obfuscation algorithm applied to it. The effect of this is that there are random offsets added to both latitude and longitude, ranging from as little as 50m to as much as 500m.” Chinese map companies are obliged to use GCJ-02 so their maps and imagery line up; outside China, companies can choose to use Chinese data and imagery and have alignment artifacts at the Chinese border, or use Chinese data with images aligned with WGS-84 and have the roads appear offset from the imagery. [Kottke]
Satellite Imagery of the Eruption Near Grindavík
The Copernicus-2A satellite imaged the smoke plume and lava flow from the eruption of the Fagradalsfjall volcano near Grindavík, Iceland yesterday; Marco Langbroek processed natural-colour and short-wave infrared imagery to achieve the above image, which he posted to Bluesky. [Kottke]
Previously: Earthquake Swarms and an Imminent Eruption in Iceland.
The Aftermath of the Kakhovka Dam’s Destruction
NASA Earth Observatory has before-and-after satellite imagery showing the impact of the destruction of Ukraine’s Kakhovka Dam last month. The Kakhovka Reservoir is emptying out (above), the irrigation canals that relied on that reservoir are drying out, and there was flooding downriver of the dam in the immediate aftermath of the breach.
Bakhmut in Satellite Imagery
CNN: “Before-and-after satellite imagery below shows the damage done to the hard-hit eastern Ukrainian city of Bakhmut over the past year.”
Updated Satellite Imagery of Ukraine Reveals Russian Fortifications, Damage
Recent satellite imagery reveals the extent of Russian defensive fortifications built in the past few months in occupied territory in anticipation of Ukraine’s spring counteroffensive: see coverage from CNN and Reuters. Meanwhile, Maps Mania reports that Google Maps’ updated satellite imagery of Ukraine shows the damage inflicted by the Russian invasion.
Satellite Observations of Ukraine’s Wheat Harvest
Satellite observations have made it possible to evaluate the success of Ukraine’s wheat and barley harvest, even in active war zones or occupied territories. NASA Earth Observatory reports that the harvest was, in the end, larger than expected: “At the outset of Russia’s full-scale invasion in February, some analysts cautioned that 20 to 30 percent of Ukraine’s winter crops might not be harvested at the end of the summer. However, NASA Harvest’s analysis indicates that 94 percent of the winter crop was harvested, including 88 percent of winter crops in areas not controlled by Ukraine.”
Tracking the Russian Invasion of Ukraine with Satellite Imagery
Bloomberg’s MapLab newsletter looks at how freely available satellite imagery has enabled widespread monitoring of the Russian invasion of Ukraine.
When the invasion of Ukraine started, these images started popping up on social media and in the news so often that it seems like most of us have access to advanced satellite imagery intelligence in real time. […] But the role of commercial providers in acquiring and sharing so many images with such regularity is unprecedented. Their rise has made military-grade intelligence available to pretty much everyone who wishes to look into it.
What’s notable is that because the satellites are commercial, the images aren’t classified.
Google Didn’t Stop Obscuring Imagery of Russian Military Sites Because the Imagery Hadn’t Been Obscured in the First Place
Yesterday, reports that Google Maps had stopped obscuring satellite imagery of sensitive Russian military facilities spread like wildfire across Twitter. Only there was no official announcement from Google saying they’d done so, and while Ukrainian Twitter was seriously running with it, I wanted to see some confirmation from the mapping side. In the event, an update to Ars Technica’s story says that Google hadn’t stopped blurring the imagery—the imagery hadn’t been blurred in the first place. “A Google spokesperson told Ars that the company hasn’t changed anything with regard to blurring out sensitive sites in Russia, so perhaps none of us were looking closely until now.”
Mapping the Russian Invasion of Ukraine: Roundup #2
Content warning: Some of these links contain disturbing images: I’ve marked them with a †.
More on the question of whether theatre maps accurately reflect the ground situation. Nathan Ruser’s maps have been used to argue that Russian forces are controlling roads rather than territory, but Ruser complains that his maps are being misinterpreted: they were never meant to show territorial control, just troop movements. See also this Twitter thread from Jennifer Cafarella, in which she explains the methodology and reasoning behind her team’s maps.
3D models of bombing damage.† Satellite imagery and 3D photogrammetric data are used to create 3D models of bombing damage in Ukraine. [Maps Mania]
A map of attacks on civilian targets† with photo and video documentation. [Nataliya Gumenyuk]
Where hot spots are literally hot spots. In a Twitter thread, Sotris Valkaniotis shows how military operations in Ukraine show up in Landsat spectral imagery: weapons fire turns up as hot spots showing “very high temperature in short-wave infrared band.”
A Ukrainian map of alleged Russian casualties† and where they were deployed from. [Michael Weiss]
A map of checkpoint traffic. More than two million Ukrainians have fled the Russian invasion. Overwhelmingly, they’re fleeing westward. This map shows how busy each border checkpoint is: Polish border crossings are extremely congested. [Kyiv Independent]
Meanwhile, Kenneth Field has been working on ways to map Ukraine’s refugees. Here’s his most recent iteration:
Update to my illustrative #Ukraine refugee map.
Adds more displaced grey dots to major populated areas.
Adds same stippled symbology to Russian incursion to indicate fuzziness of invasion (neither lines nor areas).#cartography #StandWithUkraine 💙💛 pic.twitter.com/QOyA8RaRi0
— Kenneth Field (@kennethfield) March 8, 2022
Ukraine’s population density. More than 41 million people live in Ukraine. This map from Airwars shows the population density per square kilometre. Which shows how many people in an area are affected by a particular military strike.
Apple says Crimea is Ukrainian. Mashable: “Apple’s Maps and Weather apps now mark Crimea as part of Ukraine when accessed outside of Russia. It appears the company has quietly updated its stance on the territorial dispute.” Apple had marked Crimea as Russian in 2019, which pissed Ukraine off at the time. [TechCrunch]
Finally, this striking bit of art:
By Ukrainian tattoo artist Eugene Anatsky pic.twitter.com/qVybeGYAuE
— Olga Tokariuk (@olgatokariuk) March 5, 2022
The Rise and Fall of Hunga Tonga-Hunga Ha‘apai
A storymap from Esri’s Robert Waterman, based on Maxar satellite imagery, shows the rise and fall of Hunga Tonga and Hunga Ha‘apai from being two separate islands before a 2015 eruption combined them, through its time as an apparently stable but awkwardly compound-named single island until it got blown apart last month.
Previously: Hunga Tonga-Hunga Ha‘apai, Before and After.
How Satellites Revealed the Hunga-Tonga Hunga-Ha’apai Eruption
The BBC’s Jonathan Amos looks at the ways satellites have collected imagery and data on the Hunga-Tonga Hunga-Ha’apai1 volcanic eruption.
Erin Davis’s Average Colours of the World
Erin Davis has created maps showing the average colour of each country of the world (plus maps showing the average colour of each U.S. state and county). She derived the average colour from Sentinel-2 natural-colour satellite imagery; she appends the process and the code to the end of her post. [My Modern Met]
More on the Western U.S. Wildfires
NASA Earth Observatory has had several stories on the western U.S. wildfires, gathered here. This story summarizes the situation; satellite images of the smoke generated by the fires can be seen here, here and here.
In today's Sunday edition of @washingtonpost pic.twitter.com/qHosujRKrG
— Lauren Tierney (@tierneyl) September 13, 2020
Marena Brinkhurst of Mapbox has a comprehensive list of open data sources relating to the wildfires, smoke, and air quality.
Mark Altaweel at GIS Lounge looks at how GIS is being used to map wildfires, smoke and air pollution.
Previously: California Wildfires, 2020 Edition.
Red and Blue vs. Gray and Green
The New York Times uses the colours in aerial images as a proxy for political leanings: rather than red-and-blue electoral maps, the political landscape, Tim Wallace and Krishna Karra argue, is more green and gray.
The pattern we observe here is consistent with the urban-rural divide we’re accustomed to seeing on traditional maps of election results. What spans the divide—the suburbs represented by transition colors—can be crucial to winning elections. […] At each extreme of the political spectrum, the most Democratic areas tend to be heavily developed, while the most Republican areas are a more varied mix: not only suburbs, but farms and forests, as well as lands dominated by rock, sand or clay.
This is a generalization, to be sure, but so are most political maps, and the notion that urban areas tend to vote Democratic while rural areas tend to vote Republican isn’t what I’d call a revelation. Still.