GIS Definitions

---

ArcExplorer- ESRI's (Environmental Systems Research Institute) free, simplified version of ArcView that is downloadable from the Internet. http://www.esri.com/company/free.html#software

ArcView- ESRI's (Environmental Systems Research Institute) version of a Geographic Information System.

Coverage- A set of associated data considered as a unit. Usually represents a single theme such as soils, streams, roads or land use.

Digitize- The process of converting the location of geographic features by storing their x,y coordinates in a computer file (shapefile).

Metadata- Data about data. Information will include what the data is about, what location it covers, what time period it covers, when the data was collected, who collected the data, the purpose of the data, what related data sets are available, etc.

Orthophotoquad- An aerial photo of a US Geological Survey defined quadrangle.

Theme- A coverage, when loaded into a GIS program, is often referred to as a theme. Can also be referred to as a data layer.

Using ArcExplorer

1. Open ArcExplorer (double click on the icon on your desktop). 2. Add Theme(s) to the view either by clicking the button on the toolbar or using the theme drop down menu and selecting add theme.

3. To change the appearance of a theme you have added, double click on the name of the theme. The theme properties box will appear allowing you to change the classification of the data (single symbol, graduated or unique value), label features, and change colors of a theme.

4. Use the query builder to build a precise definition of what data you want to select. Multiple attributes, operators and calculations can be used to create a complex expression.

Back to NRI GIS Data Page
Iowa GIS Information
Minnesota GIS Information