Denali’s New Elevation
A new, official height for Denali has been measured at 20,310 feet, just 10 feet less than the previous elevation, which was established using 1950s era technology. The 2015 measurement was made with modern GPS survey equipment, combined with improved gravity data. NASA Earth Observatory has an Image of the Day article about the new elevation and recent name change of North America’s highest peak. The article displays a Landsat 8 image that incorporates elevation data to show the topography of the mountain.
Coastal National Elevation Database (CoNED) Applications Project
The USGS Earth Resources Observation and Science (EROS) Center with sponsorship from the USGS Coastal and Marine Geology Program recently launched a Web site for the Coastal National Elevation Database (CoNED) Applications Project. Many applications of geospatial data in coastal environments require detailed knowledge of the integrated near-shore topography and bathymetry (topobathymetry). This site features information related to scientific research, new algorithms and methods, and topobathymetric elevation models. Finally, this site also features links to a CoNED Project Viewer and data download capabilities.
Landsat 8 Goes Over the Top
On June 21, 2014, Landsat 8 acquired an unbroken swath of 52 individual scenes over the Arctic. The midnight sun of the summer solstice allowed scientists to see more of the color and diversity of snow, ice, and cloud formations. Starting in Scandinavia, Landsat 8 cut across the Arctic Circle, northern Greenland, and through Canada’s Nunavut and Northwest Territories. NASA released a video of the imagery, along with close-up views of some favorite scenes, on its NASA Earth Observatory Web site. The swath is a good demonstration of how the Earth-observing satellite can monitor change over time in remote locations on the globe.
Climate and Land Use Change Mission Area
The USGS Climate and Land Use Change Mission Area recently launched an updated and expanded Web site. The site features news, science features, a quarterly newsletter, information on how to access data, and links to specific science activities. Learn more about the science that helps the USGS understand a changing world and how it impacts our natural resources, our livelihoods, and our communities.
Landsat’s Return on Investment
What is the real value of the Landsat program? The Landsat Advisory Group, a team of commercial, state/local government, and non-government geospatial information experts, has been working on an answer. They concluded that the economic value of just one year of Landsat data far exceeds the multi-year total cost of building, launching, and managing Landsat satellites and sensors. It’s a stunning return on investment for the program that collects consistent, continuous land change data and distributes it freely online.
Read the USGS Top Story Science Feature for more details about the study.
Case Studies of Landsat Imagery Use
Open-access Satellite Data
Changes in land cover affect the global climate by absorbing and reflecting solar radiation, and by altering fluxes of heat, water vapor, carbon dioxide, and other trace gases. Detailed assessments—regional, global, daily, and seasonal—of land use and land cover are needed to monitor biodiversity loss and ecosystem dynamics. Satellite imagery is the best source of such data, especially over large areas. In many cases, satellite data are restricted or charged for. Not true for U.S. Geological Survey (USGS) satellite imagery.
A new era of open-access satellite data began in 2008 when the USGS released its Landsat archive, the world’s largest collection of Earth imagery, to the public free of charge. Monitoring land cover change in near-real time is now a reality. According to an article by Michael A. Wulder and Nicholas C. Coops in Nature magazine, “Freely available satellite imagery will improve science and environmental-monitoring products.” Read the full story here.
Observing Earth Today and Tomorrow: A National Plan
Humans have been observing Earth for a very long time simply because the conditions of the Earth are basic to our survival and our prosperity. Even the most ancient written records are filled with accounts of great floods, famines, and earthquakes. When to plant and when to harvest, how to use precious water resources most effectively, and ways to avoid natural disasters are all age-old challenges that have encouraged Earth observation from the beginning of civilization. Read the full story here.
Landsat’s Lunar Scans
Even though Landsat 8 is an Earth-imaging satellite, it was designed to turn away from Earth once a month and scan the moon. Landsat’s sensors need to detect light consistently over time. The best way to measure Landsat’s performance is to compare it to a stable source of light. The calibration team at the NASA Goddard Space Flight Center and the USGS EROS Center use the most stable light source they can—moonlight. With these lunar scans, the engineers can adjust the calculations that turn Landsat’s data into accurate land cover information. Read the full story here and see a video created by NASA Goddard that demonstrates in detail how Landsat 8 conducts its lunar scan.
National Land Cover Database 2011 on YouTube
Learn more about the National Land Cover Database 2011 (NLCD 2011) from Dr. Collin Homer, USGS Earth Resources Observation and Science (EROS) Center. In a YouTube video presentation, Homer describes the status, future plans, and applications examples of NLCD 2011. The presentation clearly describes NLCD’s flagship products: land cover, canopy, and imperviousness. Homer emphasizes that NLCD is valuable because it is consistent and relevant. Its national coverage also supports many different applications: fire, urban development, insect damage, mining, and more. Find out what Homer means by "30 billion pixels served" at https://www.youtube.com/watch?v=GekyUrZoYys.