raster data


GIS Learning

Explorer for ArcGIS released by Esri for Mac OS.

What is GIS?

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.

GIS Data

Click and drag the slider bar to compare these LDCM images, which zoom into the area around Fort Collins, Colo. On the left, the image is shown in natural color, created using data from OLI spectral bands 2 (blue), 3 (green), and 4 (red). The image on the right was created using data from OLI bands 3 (green), 5 (near infrared), and 7 (short wave infrared 2) displayed as blue, green and red, respectively. In the left-hand natural color image, the city's elongated Horsetooth Reservoir, a source of drinking water, lies west of the city. A dark wildfire burn scar from the Galena Fire is visible just to the left of the reservoir. The scar shows up bright, rusty red in the false color image.

Imagery and Its Use in GIS

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.

GIS Data

GMTED2010 - Global elevation data.Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) - Global elevation data. Source: USGS.

New Global Elevation Data Available to Download: Global Multi-resolution Terrain Elevation Data 2010

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 […]