Friday, October 23, 2009

How to download Landsat images

The Landsat Earth observing satellites have assembled an essential record of moderate-resolution data sets of the planet’s surface features that can now be downloaded via the internet. The nearly four decades of data provide a valuable resource for scientists and decision makers concerned with changes to the land surface, as do the daily, current observations.

The Landsat Satellite Image series began in 1972. Each image in the archive covers an area of 185 by 185 km. Although technical changes have occurred over the 37-plus years of observation, the data in the archive are fully compatible with the current acquisitions. The series has maintained a consistent multispectral coverage using a range of instruments that were built specifically for the Landsat missions and that are upgraded regularly.

As of 31 December 2008, over 2.3 million individual scenes are available from the U.S. archive, and an estimated 4.7 million are available through a network of international ground stations.

Landsat data have recorded many of the natural and anthropogenic changes that have occurred in the global land surface. The effects of hurricanes, floods, tsunamis and wildfires, as well as urban growth, the Chernobyl incident and the clearing of tropical forests have been studied by scientists, resource managers, environmental planners and government agency representatives by using Landsat data.

As announced at the GEO-V plenary last November, all of the Landsat data in the U.S. archive are available for download at no cost over the Internet; images can be previewed and downloaded from http://glovis.usgs.gov or http://earthexplorer.usgs.gov.

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