Menu options provide the opportunity for searching the online catalog of other GIS data based on project or theme. Scripts start up the HTML viewer to access the project index or the theme index. The management of the GIS system is assisted by access to the information contained in these files. These files identify currently active GIS data sets and those data sets that have been archived to tape. Descriptions of the data sets, associated tables, source scale, final disposition, and digital capture procedure provide sufficient information for the review and management of many of the GIS data sets.
Some data sets are inherently more complex.
Some require extensive coordinate or feature adjustment to match the project base data set. Some have been updated because of changes in the spatial or attribute components or both. More accurate coordinate information may have become available. Changes may have occurred in the representation of the spatial features such as boundary changes, construction of a road, or addition of sampling locations, etc. The attributes may represent periodic reporting of sampling data.