Tag: satellite

Some Google Maps Updates

Published on by Jonathan Crowe

Google Maps imagery updates include improved satellite imagery thanks to an AI model that removes clouds, shadows and haze, plus “one of the biggest updates to Street View yet, with new imagery in almost 80 countries—some of which will have Street View imagery for the very first time.” The web version of Google Earth will be updated with access to more historical imagery and better project and file organization, plus a new abstract basemap layer. [PetaPixel]

Meanwhile, The Verge reports that Google Maps is cracking down on business pages that violate its policy against fake ratings and reviews.

A Look Back at the SRTM

Published on by Jonathan Crowe

Last month NASA Earth Observatory ran a two-part series about the Shuttle Radar Topography Mission, which produced a high-resolution digital elevation model of the Earth based on radar data collected by the shuttle Endeavour in 2000. The first part looks at how Endeavour gathered the data, the second part at how it’s been used.

Nearly a quarter century after the mission to map the world, the SRTM’s data still yields results. Just this year, it aided in wildfire forecasting for Iran’s Zagros Mountains, tracking soil erosion in South Africa, assessing flood risk on the coast of Brazil, and even determining how the locations of power-generating wind turbines affect real estate values. Tens of thousands of research papers are published every year that rely on SRTM maps for these and other environmental, economic, agricultural, and public safety studies.

Canada’s Early Wildfire Season

Published on by Jonathan Crowe
A map of northern North America showing atmospheric carbon monoxide concentrations that correlate with wildfires in northern Canada, from the European Space Agency.
European Space Agency

Another year, another map from the European Space Agency showing the extent of Canada’s wildfires based on data from the Copernicus Sentinel-5P satellite. It’s not nearly as bad as last year’s, but it’s way earlier. The above is a frame from an animated map showing carbon monoxide concentrations earlier this month. “The extremely high concentrations, depicted in dark shades of orange, can be linked to active fires during this time period.”

Previously: Two Ways to Visualize Canada’s Wildfires.

Google, EDF Partner to Build Map of Global Methane Emissions

Published on by Jonathan Crowe

Methane is a greenhouse gas, more powerful than CO2 but shorter-lived. Google is partnering with the Environmental Defense Fund to map global methane emissions, much of which result from leaks from fossil fuel infrastructure and are undercounted. The EDF’s MethaneSAT satellite (itself a partnership between the EDF and New Zealand’s space agency) launches next month: it’ll measure methane emissions at high resolution. Google’s bringing to the party algorithms and AI, the latter to build a global map of oil and gas infrastructure.

Once we have this complete infrastructure map, we can overlay the MethaneSAT data that shows where methane is coming from. When the two maps are lined up, we can see how emissions correspond to specific infrastructure and obtain a far better understanding of the types of sources that generally contribute most to methane leaks. This information is incredibly valuable to anticipate and mitigate emissions in oil and gas infrastructure that is generally most susceptible to leaks.

More at The Verge.

Previously: Mapping Methane Emissions.

Mapping Global Sea Levels at Even Finer Resolution

Published on by Jonathan Crowe

Launched in December 2022, the Surface Water and Ocean Topography (SWOT) satellite measures ocean surface topography—i.e., sea surface height. It recently completed its first full 21-day science orbit, which is represented in the above animated globe.

The animation shows sea surface height anomalies around the world: Red and orange indicate ocean heights that were higher than the global mean sea surface height, while blue represents heights lower than the mean. Sea level differences can highlight ocean currents, like the Gulf Stream coming off the U.S. East Coast or the Kuroshio current off the east coast of Japan. Sea surface height can also indicate regions of relatively warmer water—like the eastern part of the equatorial Pacific Ocean during an El Niño—because water expands as it warms.

Sea surface height has been measured by earlier satellites (previously); SWOT does so at a much greater level of detail.

Two Ways to Visualize Canada’s Wildfires

Published on by Jonathan Crowe

European Space Agency map of Canada showing average concentration of carboon monoxide for 1 May to 13 June 2023.

The European Space Agency released this map showing the impact on atmospheric carbon monoxide from Canadian forest fires. “Using data from the Copernicus Sentinel-5P mission, the image shows the average concentration of carbon monoxide for 1 May to 13 June. The extremely high concentrations, which are depicted in deep tones of orange, can be linked to active fires during the time. The image also shows how this air pollutant was carried as far as New York in the USA and over the Atlantic.”

Also from the ESA: this animated map of fire outbreaks in Canada during the same period.

Previously: Fire and Smoke Forecast Maps; Wildfires in Alberta.

Mapping the Russian Invasion of Ukraine: Roundup #2

Published on by Jonathan Crowe

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:

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:

Looking for Lightning, Finding Meteors

Published on by Jonathan Crowe

Map of bolides detected from space by the Geostationary Lightning Mapper
NASA Earth Observatory/Joshua Stevens

It turns out that the Geostationary Lightning Mapper (GLM) aboard the GOES-16 and GOES-17 earth observing satellites can do more than just detect lightning—it can also detect bolides, or very bright meteors, thanks to a new automatic detection algorithm. NASA Earth Observatory: “The map above shows the distribution of more than 3,000 bolides detected by the GLMs aboard GOES-16 and GOES-17 between July 2017 and January 2022. Blue points are bolides detected by GOES-16; pink points were detected by GOES-17. The lone pink point over the Atlantic Ocean was detected by GOES-17 during its commissioning phase before it was moved into its operational orbit over the West Coast.” (Bolides in the middle of the map are detected by both, and as you can see there’s a bit of parallax.)

The Mother of Landsat

Published on by Jonathan Crowe

Virginia Tower Northwood is sometimes called “the mother of Landsat” for her invention of the multispectral scanner that was launched aboard Landsat 1. An alumna of MIT, she is the subject of this long profile by Alice Dragoon in the MIT Technology Review, which looks her entire career, which prior to Landsat involved radar and antenna design—including, notably, the transmitter on the Surveyor 1 lunar lander. See also this profile on NASA’s Landsat Science page.

Climate from Space

Published on by Jonathan Crowe

ESA

The European Space Agency’s new Climate from Space website presents satellite data on a host of different climate indicators, from aerosols to CO2, from land cover to sea ice, via 3D virtual globes. From the announcement:

The new, easy-to-use site provides access to the same satellite observations used by scientists to understand climate change and support international organisations such as the United Nations Framework Convention on Climate Change (UNFCCC) and Intergovernmental Panel on Climate Change (IPCC) to drive action.

There is a suite of 21 climate data records to explore, which are generated by ESA’s Climate Change Initiative. The suite includes sea level, sea surface temperature, soil moisture, snow depth and the greenhouse gases, carbon dioxide and methane, as well as new visualisations for the latest climate variables records such as permafrost and lakes.

Online Map Tracks Nitrogen Dioxide Concentrations

Published on by Jonathan Crowe

Screenshot

A new online map tracks tropospheric global nitrogen dioxide concentrations—which we’ve seen drop sharply this year as the pandemic shut down economic activity. “This online platform uses data from the Copernicus Sentinel-5P satellite and shows the averaged nitrogen dioxide concentrations across the globe—using a 14-day moving average. Concentrations of short-lived pollutants, such as nitrogen dioxide, are indicators of changes in economic slowdowns and are comparable to changes in emissions. Using a 14 day average eliminates some effects which are caused by short term weather changes and cloud cover. The average gives an overview over the whole time period and therefore reflects trends better than shorter time periods.” [ESA]

Previously: Mapping the Lockdown-Related Drop in Emissions; Emissions Drop Due to Coronavirus Outbreak.

Mapping the Lockdown-Related Drop in Emissions

Published on by Jonathan Crowe

ESA

The European Space Agency maps the drop in nitrogen dioxide concentrations in the atmosphere in the wake of coronavirus lockdowns in many countries (see above). [GIS Lounge]

Meanwhile, CESBIO researcher Simon Gascoin built a map that compares NO2 concentrations over the last 30 days with the same period in 2019.

Data for these analyses generally come from the Copernicus Programme’s Sentinel-5P satellite. The Copernicus Atmosphere Monitoring Service issued a warning last week about using the data improperly.

Concentrations of NO2 in the atmosphere are highly variable in space and time: they typically vary by one order of magnitude within each day and quite substantially from one day to another because of the variations in emissions (for example the impacts of commuter traffic, weekdays and weekend days) as well as changes in the weather conditions. This is why, even if observations are available on a daily (currently available from satellites) or even hourly (ground-based observations) basis, it is necessary to acquire data for a substantial period of time in order to check that a statistically robust departure from normal conditions has emerged.

Cloud cover is a factor that needs to be taken into account as well.

Previously: Emissions Drop Due to Coronavirus Outbreak.