DHI.Generic.Cartography Namespace

Custom exception thrown when a Cartography error occurs

A cartography object handles a map projection and a local grid that can be translated and rotated compared to the projected coordinate system.

There are 3 levels of coordinates: Geographical coordinates (longitude, latitude) in degrees, projection coordinates (easting, northing), and model/user grid coordinates (x,y).

The ProjectionString defines the mapping from geographical coordinates to projection coordinates. See MzMapProjection for details on the projection string.

The LonOrigin, LatOrigin and Orientation defines the origin and the orientation of the model grid coordinates. It defines how the model grid coordinate system is translated and rotated, and is used to define a local coordinate system for e.g. a 2D grid axis from a dfs2 file.

See Orientation for the definition of the orientation. The model coordinates are rotated around its origin.

If Orientation is zero, and LonOrigin and LatOrigin matches the origin of the projection coordinate system (from ProjectionOrigin(String, Double, Double)), then projection coordinates equals model grid coordinates. Example: UTM-31 has projection origin at (lon,lat) = (3,0).

A map projection handles conversion from geographical coordinates (lon, lat) to projection coordintes (east, north).

The ProjectionString is a WKT string for a spatial reference system. A number of abbreviated strings also exists, i.e., "UTM-33" for a WGS-84 UTM zone 33 projection, and "LONG/LAT" for WGS-84 geographical coordinates.