The Vector Product Format
This topic applies to ArcInfo only.
The Vector Product Format (VPF) is a U.S. Department of Defense military standard that defines a standard format, structure, and organization for large geographic databases. VPF data is read-only in ArcCatalog. However, you can create Catalog-style metadata if you have write permission where the data is located. There are four levels of VPF data.
A VPF database is a collection of data that is managed as a unit. A VPF library, similar to an ArcInfo Librarian library, is a collection of coverages that falls within a defined extent and uses the same coordinate system. A VPF coverage, similar to an ArcInfo coverage, may contain many feature classes. The name of a VPF coverage is the library name followed by the coverage name. For example, a coverage named "elev" in a library named "algiers" would appear in the Catalog as "algiers:elev". Coverage names are often specified in the VPF product specification.
A VPF feature class is a collection of features (primitives) that have the same attributes. Each feature class contains point (node), line (edge), polygon (face), or annotation features and has an associated feature attribute table. The feature classes within a VPF coverage represent different types of features. For example, a hydrology coverage may have feature classes representing dams, ditches, lakes, and rivers.
A coverage's features appear continuous even though they may be tiled. They must also interconnect in a manner defined by the coverage's topology. There are four levels of topology for VPF coverages (0, 1, 2, and 3). Level 0 coverages have no topological information; Level 3 coverages have full polygon topology.
VPF tables describe the contents of databases, libraries, coverages, and feature classes. They reside within the folder and correspond to each level of data. Tables describing the database appear below its list of coverages. Tables describing a library reside within its folder along with one folder for each coverage. In turn, a coverage's folder contains tables describing its contents and one folder for each tile, if appropriate.