Orthorectified Landsat digital data now available from USGS

日前鐘老師轉寄了一封Mail來，內容是USGS提供正射過的Landsat衛星影像供"免費"下載，我覺得還蠻有趣的，就去試試了，首先就是連到USGS的網頁，http://www.usgs.gov/，然後就按VIEWER，就可以看到下載影像的視窗了，選擇影像的視窗是利用JAVA的，所以最好先到www.java.com下載新的Java安裝，都弄好了後，就可以選影像了，記得只有正射過的影像可以免費下載。


注意左上角會出現Free download的才可以免費下載。

原gisdevelopment.net上的新聞稿：


Orthorectified Landsat digital data now available from USGS

The US Geological Survey (USGS) now offers, at no cost, selected Landsat 4, 5 and 7 satellite data. Orthorectified Landsat data are available for free download from the Global Visualization Viewer (GloVis). The Landsat Orthorectified data collection is a global set of high-quality, relatively cloud-free orthorectified Landsat 4-5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper Plus (ETM+) imagery. Selected and generated through NASA Commercial Remote Sensing Program, the datasets provide two full sets of global coverage over an approximate 10-year interval (circa 1990 and circa 2000) and total nearly 16,000 scenes. Other data sets will be added as they become available, including the Landsat Orthorectified Multispectral Scanner (MSS) data set (circa 1975).
Users can download an entire scene, containing all bands, metadata, jpeg and header information in a single zipped format file.

The Landsat Program is the longest running program providing vital images of the Earth surface from space. The first Landsat satellite was launched in 1972 and since then, Landsat satellites have been providing a constant stream of moderate-resolution images. In 1999, the Landsat Program took a giant leap forward technologically with the launch of Landsat 7. The instruments on the Landsat satellites have acquired millions of images of the surface of the planet, providing a unique resource for scientists who study agriculture, geology, forestry, regional planning, education, mapping and global change research.

Source : http://www.usgs.gov