The digital terrain model was initially generated by Center for Geospatial Technology (CGIT) for the Virginia Geographic Information Network (VGIN) using the mass points and break lines from the 2002 VBMP aerial photography. This effort represents the most accurate digital terrain model (DTM) ever generated statewide for Virginia. The Triangulated Irregular Network (TIN) provides seamless coverage for each county in Virginia. TINs are used to ascertain landscape characteristics and to serve as a topographic model to support surface drapes (for imagery, etc.). Ancillary data sets are often generated from TINs. These data sets may include: slope, aspect, contours, digital elevation models, etc. Note that the DTM is appropriate for general planning purposes only.
Data Type: Tesseral
-State Plane Virginia North or South (Contingent on locality, refer to index map in the Appendix)
-Linear Unit: US Foot
-Source: The Virginia Geographic Information Network (VGIN)