The rangelands of the western United States are changing more quickly than many other parts of the lower 48. Miles upon miles of the area or semi-arid landscapes in states like Idaho, Montana and Nevada are now carpeted by fire fueling invasive grasses. Cheatgrass is the most prevalent, which is troublesome for several reasons.
Outbreaks of native bark beetles can lead to conspicuous changes in a forest landscape. They’ve been present for thousands of years with occasional outbreaks, but there’s a lot we don’t yet understand about them. Exactly when and where have outbreaks occurred? How severe were they? What happened to the forest afterward?
Fires can be destructive or healthy for a landscape—often both. Fires have grown larger and more destructive in recent years, though, thanks to human activity, climate change, and a host of other factors. Satellite data helps us to map and monitor fire activity, but the study of post-fire plant life using remote sensing data goes further than fire mapping.
Satellites like Landsat are valuable for mapping fire perimeters and for monitoring trends in burn severity or in post-fire recovery. Satellites can cover wide areas with a single pass, whereas helicopter, drone, or airplane fire line mapping can take hours.
For our third and final episode of Eyes on Earth from the September launch of Landsat 9, we hear from Virginia Norwood. She blazed a trail for women in remote sensing in the 1960s and 70s while working for Hughes Aircraft, a contractor for NASA.
Hundreds of scientists, officials, international representatives, and others witnessed the launch of Landsat 9 on September 27, 2021, from a handful of viewing sites around Santa Barbara County, California.
Landsat 9 launched into orbit from Vandenberg Space Force Base on Monday, September 27, 2021, to carry on the legacy of a nearly 50-year record of continuous Earth observation that began in 1972. The days leading up to the event saw guests from around the world descend upon Santa Barbara County in California to watch the historic event take place.
Satellite imagery is everywhere. We see it on TV news and weather coverage, in our Twitter and Facebook feeds, and on our phones’ mapping apps. The data behind that imagery is nothing like a screenshot, though.
The launch of Landsat 9 in September of 2021 represents a milestone for a joint USGS/NASA program that stretches back nearly 50 years. Landsat 9 will continue the legacy of unbroken, repeat Earth observations and contribute to our understanding of a changing planet.
The Great Lakes represent roughly 20% of the surface freshwater in the world and 90% in the United States. The Great Lakes Basin supports more than 30 million people in the U.S. and Canada and 3,500 plant and animal species. The region faces threats that range from climate change and invasive species to pollution and development.
Urban heat islands occur in areas containing more impervious surfaces and fewer natural environments. The day and night surface temperature is higher in urban heat islands than in surrounding areas. During heat waves, this can lead to greater numbers of heat-related illnesses and deaths.
The National Land Cover Database, or NLCD, was the first and remains the most well-known set of satellite-based land cover mapping products released by EROS. It sorts the each 30-by-30-meter plot of land in the United States into a land cover class, such as cropland, pasture, high-intensity developed, deciduous forest, and the like.
Mapping fire perimeters is important work. It guides post-fire restoration efforts, fire mitigation strategies, and helps track of trends in burn severity over time. In the past, many of Canada’s fire agencies relied heavily on techniques like sketch mapping, which estimate burned area without exact measurements.
The invasive species hemlock woolly adelgid is a threat to eastern hemlocks, filling some southeastern U.S. forests with what are called “gray ghosts” of the trees. Until recently, the insect had stayed in the southern part New York, but late last summer, an infestation was discovered in the Adirondacks.
About 15 million people rely on the Delaware River Basin for drinking water, including residents of Philadelphia, PA, Camden, NJ, and Wilmington, DE. What might happen to the water supply if climate change and population growth continue unabated? How might that impact land cover and land use patterns?
Teams at the USGS EROS Center have completed fire atlases for nine National Parks across the U.S. Each atlas defines the size and severity of each fire in each park since 1984, including fires too small to be mapped by other programs. Yellowstone National Park has had nearly 100 fires, for example, ranging from a few acres to thousands of acres.
Mapping land cover in the United States in the present isn’t a simple job, but satellites like Landsat make it possible. Mapping conditions in the pre-satellite era, which the LANDFIRE program does through its Biophysical Settings (BpS) GIS data products, is a far trickier proposition.
The fire science community is always on the lookout for the freshest satellite-derived fire disturbance maps. Aiming to meet those needs, the multi-agency partnership known as LANDFIRE has just released an update that adds three new years of disturbances across the U.S. to its 20-plus layers of GIS data.
It’s possible to map vegetation type with Landsat, but getting the maps right requires more than satellites alone. The teams behind LANDFIRE use an extensive network of ground control points to check their work, thereby bolstering the reliability and utility of their multi-layer GIS product suite.
Ladies of Landsat aims to help women and other underrepresented groups feel welcomed and supported in the field of remote sensing. The Twitter group has grown to 5,700 members and counting since Dr. Kate Fickas started it in 2018 during a Landsat Science Team meeting at EROS.
Deforestation is a significant concern for many parts of the globe, particularly in places like the rainforests of the Amazon or the Congo. Scientists, governments, and non-governmental organizations turn to satellite data to track deforestation, as well as to set targets for improvement.
Landsat satellites have monitoring the Earth’s surface for nearly 50 years, providing critical information for countless areas of study and real-world applications. But with observations only collected every 8-16 days, there are limits to what can be tracked.
Dr. Alan Belward has spent a lot of time thinking about the planet’s surface water. The former Landsat Science Team member uses satellite data to track changes to lakes, rivers, and streams, and recently published a book that uses Landsat data to tell some of those stories.
The St. Mary and Milk Rivers cross the U.S. and Canadian border and supply water to both countries. Managing that resource in the interest of both nations is a matter of international collaboration and cooperation, and Landsat data is helping offer objective information on water use.
The extensive rangelands across the Western United States are threatened by invasive grasses, climate change, and altered fire regimes that can disturb the landscape. The largely semi-arid lands are also important for the survival of species that need undisturbed sagebrush ecosystems to thrive.
Albedo—the amount of incoming solar radiation reflected into space from the Earth’s surface—is a key measurement for surface temperatures and plant productivity. It also factors into weather forecasting and climate modeling. Landsat Science Team member Dr.
Landsat data is more useful today than at any other point in its nearly 50-year history. The USGS Collections strategy is a major reason why. Landsat Collections align and correct satellite acquisitions from 1972 through the present to make the data easier to work with through time.
The Green Revolution leaned on fertilizers, drought-resistant seeds and other modern innovations to boost agricultural production across much of the planet in the second half of the 20th Century. But many of those innovations never reached West Africa, partially because the lack of social safety nets and crop insurance made such investments too risky.
Evapotranspiration is the process by which water transpires from the leaves and stems of plants and evaporates from the Earth’s surface. ET is an important metric for managing water use, but data availability has long been an issue.
Today, the world is awash in remotely sensed data. Satellites launched by countries and commercial companies circle the planet collecting data every day. Accessing data from multiple agencies and plaforms and turning it into useful analytics can be a daunting and complex endeavor, however.
Mapping land cover across the United States using Landsat satellite data is a difficult, time-intensive job, but there are jobs far larger. Matt Hansen, a Maryland-based professor and member of the Landsat Science Team focuses his efforts on mapping land cover and change on a global scale.
Just recently, in mid-July, the flight operations team charged with keeping the Landsat 7 satellite running smoothly achieved a major milestone. They have gone 8 straight years now without an operator error.
The U.S. Geological Survey took a bold step toward documenting change across the landscape with the launch of the first Landsat satellite in 1972. Since then, it’s collected nearly five decades of imagery. But it takes more than just imagery to understand change. It takes time, effort—and serious computing horsepower.
Between them, Landsats 7 and 8 image the entire land surface of Earth every eight days. The USGS orbiters are just two of many Earth observing satellites flying at the same altitude and collecting data at the same time of day.
The U.S. has plenty of data on wildfire risk. There are local and regional risk assessments, complex datasets like LANDFIRE and tracking tools like the EROS Fire Danger Monitor, as well as a host of resources and research projects devoted to the subject.
The continent of Australia experienced some of the most devastating wildfires in its history in late 2019 and early 2020. Remote sensing scientists in Australia, who collaborate closely with EROS, relied on satellites like Landsat to help assess and monitor the damage.
The Mendenhall Program offers a range of two-year post-doctoral research fellowships within the U.S. Geological Survey. Heather Tollerud took advantage of the program in 2015 to study drought and land cover at the USGS EROS Center, and has since become a key player in the Center’s innovative Land Change Monitoring, Assessment and Projection (LCMAP) initiative.
In the West African nation of Ghana, tropical forests are more than landscape. They are woven into language, custom, and culture. They are also the source of timber for home heating and industry, as well as barriers to agricultural production. Those are just a few of the reasons why deforestation has come alongside the nation’s rapid population growth.
For decades, each Landsat image had a price tag – a hefty one at times, ranging from $400 to as much as $4,000. That all changed in 2008 with the enactment of an open data policy that made the entire Landsat archive available for download at no cost to the user.
Landsat satellites offer a wealth of information to scientists studying ecosystem health and recovery. Data products derived from Landsat open even more areas of inquiry. Landsat Burned Area products, for example, can help researchers identify previously unknown fires that took place from 1984 through the present.
Scientists at EROS have spent years refining their approach to mapping burn severity using remotely-sensed data from satellites like Landsat, but Landsat comes with limitations. Landsat data cannot see the vegetation below a thick tree canopy, for example.
The Arctic is changing at a more rapid rate than the rest of the planet. Some of the most significant changes are tied to the thawing of near-surface permafrost, the layers of frozen soil containing vast stocks of stored carbon.
Each fall, EROS invites its staff scientists and area graduate students to visit for a noontime poster session. The poster sessions offer a change for those researchers to present their results to their peers and get feedback from their fellow scientists.
It’s easy enough to measure rainfall, and nearly as easy to measure streamflow. Calculating the efficiency of water use through the metric of evapotranspiration (ET) – evaporation off the Earth’s surface and transpiration from the leaves of plants – is a far trickier proposal.
EROS scientists track water availability and crop health around the world to help governments and non-profits manage resources and stave off food shortages. But EROS also teaches international scientists to track those resources themselves. In this episode, we hear about a recent training session at EROS for Iraq’s Ministry of Water Resources.
Sixty years of manned and unmanned space flight have left a cosmic junkyard circling the planet. In 2017, the U.S. government reported that it logged 308,984 close calls with space junk and issued 655 emergency-reportable alerts to satellite operators.
A farmer at the foot of a corn stalk can tell how well the plant is faring. That same farmer might survey his entire field for crop health. But assessing the health of crops or forests at regional, national, and international scales requires remote sensing, most often via satellite.
Land cover and land use across the United States are the culmination of a complex web of interwoven factors: Climate, landscape types, and economic factors among them. Remotely-sensed data from satellites like Landsat and a variety of other sources are useful for documenting and monitoring land cover and land use.
How much does an Earth observation satellite weigh? How are they launched? How fast does it travel? Does Landsat have a gas tank? In this episode of Eyes on Earth, we answer some of the basic questions surrounding the satellites that define the EROS mission.
Nearly 85 million people around the world are currently considered “food insecure,” and that figure continues to grow. Remote sensing technology enables scientists to feed data into the Famine Early Warning Systems Network (FEWS NET), which in turn can issue alerts that guide the distribution of humanitarian aid.
Earth observation used to be the province of a handful of countries with satellite technology. Today, hundreds of satellites built all over the world are launched every year. This episode of Eyes on Earth talks about the explosive growth in the civilian and commercial remote sensing and EROS’ role in it.
When an accident occurred at the Chernobyl Nuclear Power Plant's No. 4 reactor in Ukraine on April 26, 1986, Landsat satellites were among the first to capture visual evidence of its widespread impact. This episode of Eyes on Earth outlines how the disaster focused the world's attention on the value of remote sensing.
There’s a lot more than Landsat in the EROS Archive. In this episode of Eyes on Earth, we hear from a professor who’s mined satellite data collected during once-classified military missions to peer into the history of land use in Eastern Europe during the height of the Cold War.
We tend to associate Landsat satellites with what we see on solid Earth, but they can also tell us much about the health of our inland and coastal ecosystems. Landsat can be used to monitor harmful algal blooms, for example. Eyes on Earth guest Dr.
Every year, the USDA’s National Agricultural Statistics Service (NASS) uses data from satellites like Landsat to estimate crop types and crop yields in the United States. The result is the Cropland Data Layer (CDL), which offers an annual look at more than 100 crop categories across the country.
Summary: Scientists at EROS use tools like Landsat to produce land cover maps, which tell us if landscapes are rural or urban, cropped or forested, wetland or shrubland. Those maps help scientists at EROS and around the U.S. study the impact of changes in land use on not just landscapes, but on ecosystems, patterns of resource use, wildlife habitat, and much more.
Sorting Landsat data into an accurate and reliable record of land cover in the United States is one of the most important jobs at EROS. This episode of Eyes on Earth explores the what, how, and why of the National Land Cover Database (NLCD).
Across the planet, in rural settings on uncluttered landscapes, there are satellite antennas receiving data directly from Landsat satellites as they pass 438 miles overhead at more than 17,000 miles per hour. It happens multiple times a day, in Australia, Brazil, Canada, Germany, South Korea, and elsewhere.