Using satellite imagery
In ArcGIS, you can use the satellite imagery, as follows:
- As a basemap and background for the onscreen digitizing process
- As a source of attribute data through the visual interpretation process
- For advanced analysis using the image processing tools (for example, Normalized Difference Vegetation Index-NDVI)
The source of the Landsat 7 ETM+ satellite imagery that is used in this chapter is the Global Land Cover Facility, www.landcover.org. The Landsat data files were created by the U.S. Geological Survey (USGS), and stored in the Geographic Tagged Image-File Format (GeoTIFF). (NASA Landsat Program, 2007, Landsat ETM+ scene L71183029_02920070727, L1G, USGS, Sioux Falls, 07/27/2007)
A satellite image is a multispectral image with three or more spectral bands. A spectral band captures the spectral signature of the objects within a range of frequencies across the electromagnetic spectrum. A Landsat 7 ETM+ image includes three visible bands (blue, green, and red), five infrared...
