More information on National Geographic Database (NGD)
The main sources for the National Geographic Database include:
- Statistics Canada's street network files (SNFs)
- Elections Canada's road network file (RNF)
- National Topographic Database (NTDB) digital coverage at 1:50,000 and 1:250,000 from Natural Resources Canada, and Digital Chart of the World (DCW) coverage at 1:1,000,000
- Other information from field operation activities, municipal maps and private sector licenced holdings.
The reference layers are not edgematched at former NTDB tile limits.
Since the primary purpose of NGD is to support census and electoral activities, topological accuracy takes precedence over absolute positional accuracy.
The data are maintained and stored in the Lambert conformal conic projection based on the North American Datum of 1983 >(NAD83).
Refer to the related definitions of coordinate system; datum; map projection and Spatial Data Infrastructure (SDI).
Changes prior to the current census: