Where to Get Data
Landsat data can be freely ordered from three USGS websites. The descriptions below will help you decide which site is best for you. All Landsat data are available from USGS for free.
On July 23, 2012, on the 40th Anniversary of the launch of Landsat 1, the USGS Landsat Project rolled out a new tool that enables fast and easy viewing of 3 million Landsat images all around the globe with just a simple web browser. USGS has made exporting your display and downloading full scenes easy, but the real power of the LandsatLook Viewer is the capability to explore Earth. With a place name search tool or panning and zooming, you can easily navigate the globe. Be sure to check out the 40 years of data over your favorite place! Whether you are preparing a presentation, teaching kids, educating decision makers, or previewing the full-resolution image prior to downloading the full scenes, the LandsatLook Viewer is a new and exciting way to experience the Landsat archive.
On GloVis, you can search for data by clicking on an interactive map or by entering the geographic coordinates (latitude and longitude) of the site you are searching for. After clicking on the map or entering coordinates, the GloVis view window will appear on your screen showing you nine adjacent Landsat 7 browse images. This allows you to visually locate the best Landsat image for your purposes. Use the menu at the top of the view window to view data from different sensors, to change the browse image resolution, or to view map layers. You can use the "Add" and "Order" buttons at the lower left corner of the viewer to order data, or if a read "Downloadable" label appears on the image, you can download the data immediately. All data is now orthorectified and in GeoTIFF format.
The USGS Earth Explorer website allows you to custom tailor your search parameters for Landsat data. After entering the website (you must create a login), you can either search for data by selecting a region on a map, by entering coordinates, or by entering a place name. Additionally, you also have the option to choose your data set (e.g. "Landsat 4-5 TM", "Landsat 7 ETM+", "Landsat Orthorectified ETM+") and then select parameters such as acceptable cloud-cover percentages and the range of desired acquisition dates. + Earth Observatory's Quick Guide to Earth Explorer for Landsat 8
The NASA funded Web-enabled Landsat Data (WELD) project is systematically generating 30 meter composited Landsat Enhanced Thematic Mapper Plus (ETM+) wall-to-wall mosaics of the conterminous United States and Alaska from 2005 to 2012 on a weekly, monthly, seasonal and annual basis. These data are freely available as as custom GeoTIFF subsets via a new interactive web ordering system and as tiled HDF products via FTP. The WELD products are processed so that users do not need to apply the equations and spectral calibration coefficients and solar information to convert the ETM+ digital numbers to reflectance and brightness temperature, and successive products are defined in the same coordinate system and align precisely, making them simple to use for multi-temporal applications..
The USGS also freely offers the Landsat Orthorectified data collection which consists of a global set of high-quality, relatively cloud-free orthorectified MSS, TM and ETM+ imagery from Landsats 1-5 and 7. This dataset was selected and generated through NASA's Commercial Remote Sensing Program, as part of a cooperative effort between NASA and the commercial remote sensing community to provide users with access to quality-screened, high-resolution satellite images with global coverage over the Earth's land masses. Over 16,000 images are freely available.