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The State Geographic Information Database (SGID) contains files and links to several different categories of data sets. There are two main categories: Vector GIS data dets wherein geographic features are represented by discrete points, lines, and polygons; and, raster data sets, which represent geographic phenomena using a grid of raster cells or pixels. Generally speaking, vector data is usually used to describe features such as roads, municipal boundaries (such as cities or counties), springs, streams, airports, etc. Raster GIS data sets usually consist of data obtained from satellite or other remotely sensed data, and includes aerial photos, digital elevation models, scanned images of paper maps, etc. SGID Content Links: Depending on the type of data, different data storage formats are used. Index web pages are maintained for vector and raster data on this portal that assist with the download process for specific geographic extents. These indexes also provide a link to metadata describing the datasets in detail. Note: Most data contained within the SGID uses the Universal Transverse Mercator projected coordinate system (UTM Zone 12 North) using the 1983 North American Datum (NAD83). UTM Zone 12N, NAD 83 is the current state standard for projection, coordinate system, and datum.
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