Posts Tagged: Landsat
[Source: USGS] Just released, the latest edition of the nation’s most comprehensive look at land-surface conditions from coast to coast shows the extent of land cover types from forests to urban areas. The National Land Cover Database (NLCD 2011) is made available to the public by the U.S. Geological Survey and partners.
Dividing the lower 48 states into 9 billion geographic cells, the massive database provides consistent information about land conditions at regional to nationwide scales. Collected in repeated five-year cycles, NLCD data is used by resource managers and decision-makers to conduct ecosystem studies, determine spatial patterns of biodiversity, trace indications of climate change, and develop best practices in land management.
Based on Landsat satellite imagery taken in 2011, NLCD 2011 describes the land cover of each 30-meter cell of land in the conterminous United States and identifies which ones have changed since the year 2006. Nearly six such cells — each 98 feet long and wide — would fit on a football field. Land cover is broadly defined as the biophysical pattern of natural vegetation, agriculture, and urban areas. It is shaped by both natural processes and human influences. NLCD 2011 updates the previous database version, NLCD 2006.
Webinar about the release will be Tuesday, April 15, 2014, 2:00 PM Eastern Time: "New Version of the National Land Cover Database - April 4, 2014 Release”
The latest version of the National Land Cover Database (NLCD) for the conterminous United States will be publicly released on April 4, 2014. NLCD 2011 is the most up-to-date and extensive iteration of the National Land Cover Database, the definitive Landsat-based, 30-meter resolution land cover database for the Nation. NLCD 2011 products are completely integrated with those of previous versions (2001, 2006), providing a 10-year record of change for the Nation. Products include 16 classes of land cover, the percent of imperviousness in urban areas, and the percent of tree canopy cover. NLCD is constructed by the 10-member federal interagency Multi-Resolution Land Characteristics (MRLC) Consortium. This seminar will highlight the new features of NLCD 2011 and the related applicationsCollin Homer, 605-594-2714, firstname.lastname@example.org)
For more information and to download NLCD data, visit http://www.mrlc.gov/.
Please click the following link to join the webinar:
At start time of the webinar, each location must call one of the dial-in numbers:
From the National Center in Reston, dial internally x4848
From all other USGS/DOI locations, dial 703-648-4848
From non DOI locations, dial toll free 855-547-8255
After the voice prompt, please enter the Conference Security Code 73848024 followed by the # key. You will hear a tone confirming that you have successfully joined the conference call. If you weren't successful, you will hear another voice prompt with instructions.
Thanks to Dave Thau, Karin Tuxen-Bettman, John Bailey, and Emily Henderson who came to visit the GIF and give a demo of the GEE toolbox. We went over the guts of GEE, Timelapse (very cool: make your own! Here is mine), the GEE GUI framework, and the GEE API. Very fun afternoon!
It's meta-gorgeous, and better than spy vs spy: Landsat 8 catches a glimpse of its older, retired uncle Landsat 5. From NASA:
Feb 14, 2014 • Eight months ago, on June 5, 2013, the U.S. Geological Survey decommissioned the venerable Landsat 5 satellite. That day, the USGS Landsat Flight Operations Team transmitted the last command to Landsat 5, effectively terminating the mission and leaving it in a disposal orbit.
This week, Landsat 8 overflew the defunct Landsat 5, and thanks to some clever work by Mike Gartley, a Research Scientist with the Digital Imaging and Remote Sensing group at Rochester Institute of Technology (RIT)—a group that has long participated in Landsat calibration and validation—Landsat 5 was seen in an image taken by Landsat 8.
In these images, the satellite is seen as a streak of pixels (dark or light depending on the spectral band). There is one image from each of Landsat 8′s OLI bands, except for Band 7, or SWIR-2, where she blended into the clouds and was impossible to distinguish. In these images Landsat 5 is much closer to Landsat 8 than she is to the Earth. More here./span>
I am working on a retrospective of remote sensing of forests in California for the centennial. I am trying to highlight some of the pioneering work done by remote sensors that focused on Californian forests from the 1960s through the use of lidar today.
Of course with this topic you must begin with Robert N. Colwell. Dr. Colwell was an internationally renowned remote sensing scientist; he was former associate director of the Space Sciences Laboratory at the UC Berkeley, and he was the instructor of remote sensing in our own Mulford Hall from 1947 until his retirement in 1983. He was NASA co-investigator for Apollo IX, and his research in the 1960s on reflectance and multispectral reconnaissance were the primary basis for selecting the type of sensors and the spectral bands implemented in Landsat. Neat guy, and we all benefit from his intellectual legacy.
Anyway, for this paper, I am going through some of his work as he transitioned from aerial photography to digital imaging, and I came across this picture. Mulford is just off the scene in the upper left corner. In his caption he says:
"Oblique aerial view of Berkeley Campus of University of California taken with Camouflage Detection film." (That is what they used to call color infrared.) "Such photography is superior to any other for certain photo interpretation purposes as indicated by some of the preceding examples. Note in this photo how color values for each species of tree tend to remain uniform from foreground to background because of the superior haze penetration offered by this film. The relatively long wavelengths to which this infrared-sensitive film reacts are scattered but very little by atmospheric haze particles, thus accounting for the uniform color values and for excellent image sharpness." I dig this part: "The original color transparencies have the same color values as seen here and consequently make very attractive panels for lamp shades, although certain of their colors fade upon prolonged exposure to light."
The trend for using maps as home decorations PRE-DATES 1970! Take that hipsters!
Article source: Colwell, R.N. 1964. Aerial photography - A valuable sensor for the scientist. American Scientist, Vol. 52, No. 1 (MARCH 1964), pp. 16-49
Some more about him here: http://senate.universityofcalifornia.edu/inmemoriam/robertcolwell.htm/span>
Lots of exciting sharing this week!
A new high-resolution global map of forest loss and gain has been created with the help of Google Earth. The interactive online tool is publicly available and zooms in to a remarkably high level of local detail - a resolution of 30m. Snapshot of Russia here (green = forest, blue = gain, red = loss):
Results from time-series analysis of 654,178 Landsat images from 2000–2012 characterize forest extent and change. Between 2000 and 2012, according to this analysis, the Earth lost a combined "forest" the size of Mongolia. http://www.bbc.co.uk/news/science-environment-24934790
Here is the abstract from the accompanying paper in Science:
Quantification of global forest change has been lacking despite the recognized importance of forest ecosystem services. In this study, Earth observation satellite data were used to map global forest loss (2.3 million square kilometers) and gain (0.8 million square kilometers) from 2000 to 2012 at a spatial resolution of 30 meters. The tropics were the only climate domain to exhibit a trend, with forest loss increasing by 2101 square kilometers per year. Brazil’s well-documented reduction in deforestation was offset by increasing forest loss in Indonesia, Malaysia, Paraguay, Bolivia, Zambia, Angola, and elsewhere. Intensive forestry practiced within subtropical forests resulted in the highest rates of forest change globally. Boreal forest loss due largely to fire and forestry was second to that in the tropics in absolute and proportional terms. These results depict a globally consistent and locally relevant record of forest change.
Hansen, M.C.; Potapov, P.V.; Moore, R.; Hancher, M.; Turubanova, S.A.; Tyukavina, A.; Thau, D.; Stehman, S.V.; Goetz, S.J.; Loveland, T.R.; Kommareddy, A.; Egorov, A.; Chini, L.; Justice, C.O.; Townshend, J.R.G. High-Resolution Global Maps of 21st-Century Forest Cover Change. Science 2013, 342, 850-853/span>/span>