North Dakota GIS Hub Standards

Data destined for the Hub should meet the following:

Required:

No special characters or blanks in the layer name.
Layer name length is limited to 20 characters, which includes the _Pts, _Poly, or _Line suffix.
Consistent and unique layer names, e.g., consistent - use countyroads and cityroads, not roadscounty and cityroads; unique - there can only be one "counties" layer in the entire database.
Data is in shapefile or coverage format.
Data is in NAD83.
Metadata meets FGDC or North Dakota standards (if using FGDC, then please also include X-shift and Y-shift which are in the North Dakota standards).
Data that coincides with the state border is clipped to the Hub state boundary layer, e.g., NDHUB.State_Poly.

Preferred:

Data is in Geographic Coordinate System. If not, please specify the projection.
Please check to be sure that the projection file (.prj) is supplied (if applicable).
Metadata is in FGDC text format (unless data is in shapefile or coverage format, then the metadata is probably in XML format).

Storage - Coordinate System and Datum

The North Dakota GIS Hub (NDGH) geodatabase stores the spatial data in geographic coordinates, using the North American Datum of 1983 (NAD83). The North Dakota GISTC believes that this is the best, all-purpose coordinate system and datum that allows maximum flexibility for GIS professionals and their GIS and GPS software within North Dakota, as the state has two UTM zones and two State Plane zones. The geographic coordinate system is the most flexible system for both ArcView 3.x and ArcGIS 8.x users.

The North Dakota GISTC recommends the use of the North American Vertical Datum of 1988 (NAVD88) for data containing elevations.

Storage - Precision

The NDGH geodatabase is capable of storing data to a resolution of at least 0.0017 feet at a state-wide extent of -105.5 to -95.5 degrees longitude and 45.0 to 55.0 degrees latitude. When vector or raster data is loaded into the geodatabase, the automatically defined geodatabase spatial grid index is normally used. The spatial grid index size is manually adjusted for data sets with greater than 50,000 records.

Metadata

Please see the metadata section for this information.

Data Organization

Vector data stored on the NDGH geodatabase is organized by data sets, called feature datasets in geodatabase terminology, that reflect major groupings of data, e.g., Transportion for all things related to transportation within the state.

Within each feature data set, resides the layers, or in geodatabase terminology, feature classes.

Raster data is stored on the NDGH geodatabase strictly by name, as the ESRI geodatabase lacks the ability to organize raster data as it does the vector data.

Naming Conventions

Names used on the NDGH were chosen by the North Dakota GISTC to be both succinct and descriptive. Layers have a maximum of 20 characters in their name, exclusive of the "NDHUB" prefix.

Suffixes of _Poly, _Line, and _Pts are given to each of the layers to assist the GIS user in a number of ways. ArcMap users will see the icons to the left of each layer name and thus really do not need the suffix. ArcView 3.x users do not have this icon, and thus will find this suffix to be useful.

All ESRI software users will find it beneficial to distinguish between the data sets suffixed with _Line and _Poly. A layer with the _Line suffix denotes "arcs" as used in ArcInfo and is most useful for defining specific line attributes, e.g., setting the east border line of a county to a wider line. A layer with the _Poly suffix is most useful for geoprocessing, selection of data, and for setting the attributes of the fill, e.g., pattern and transparency . Layers with the _Pts suffix is there for compatibility with the other suffixes.