GIS is a technological field that incorporates geographical features with tabular data in order to map, analyze, and assess real-world problems. The key word to this technology is Geography – this means that some portion of the data is spatial.
Most imagery for use in GIS projects consist of satellite images or aerial photographs but it can also include, thermal images, digital elevation models (DEMs), scanned maps and land classification maps. This article examines imagery and how to effectively gather, store, process and interpret it for a variety of different GIS projects.
The U.S. Geological Survey (USGS) and the National Geospatial-Intelligence Agency (NGA) have released an updated and more accurate global elevation model that pulls data from Digital Terrain Elevation Data (DTED®) from the Shuttle Radar Topography Mission (SRTM); Canadian elevation data; SPOT 5 Reference 3D data; data from NASA’s Ice, Cloud, and […]
Digital imagery can greatly enhance a GIS. Part of the raster data types, imagery is a powerful visual aid and serves as a source of derivative information such as planimetrics and classification schemes to derive such information as land use or vegetation. If your GIS covers a particularly large area, […]