Free Data Sources
Landsat 8 Web Mapping: Evolution
Evolution allows both access to Landsat 8 imagery and the ability to compute a time-series GIF animation;.
The NOAA View project from NOAA allows users to explore visualizations of Ocean, Land, Atmosphere, Cryosphere, and Climate data sets. There are multiple subsets and data sets can be displayed, with a basic explanation of each, by week, month, and year.
Open-Source Landsat 8 Processing Tools
MapBox has developed a process that allows the user to create an interactive map from Landsat 8 imagery using free open-source image-processing and map-making tools. Step-by-step instructions are available at http://www.mapbox.com/blog/processing-landsat-8/.
NebraskaMAP provides public and private access to peer-reviewed Nebraska Spatial Data Infrastructure (NESDI) and other statewide geodata, maps, and GIS web services for Nebraska. http://www.NebraskaMAP.gov/
NE Farm Service Agency DOQQs
The Nebraska Department of Natural Resources Data Bank offers Rectified Digital Imagery for free download
NE Digital Raster Graphics (DRGs)
Can be downloaded for free from the University of Nebraska School of Natural Resources
Google's Landsat Viewer
Google's Landsat Annual Timelapse viewer is an interactive video that allows user to pan and zoom anywhere on Earth and view annual mosaics from 1984 to the present at the resolution of a Landsat pixel. Users can create custom views of their own areas of interest by zooming and panning to a particular view, and then clicking the "Share this view" button, which produces a custom URL that you can send to anyone. Alternatively, a user can construct URLs by inserting the appropriate latitude, longitude, and zoom level.