Description
This is a specialized map projection that does not take into account the curvature of the earth. It's designed for very large-scale mapping applications.
Projection method
The coordinates of the center of the area of interest define the origin of the local coordinate system. The plane is tangent to the spheroid at that point, and the differences in z-values are negligible between corresponding points on the spheroid and the plane. Because the differences in z-values are ignored, distortions will greatly increase beyond roughly 1° from the origin. This map projection is the same as the Orthographic projection, but supported on spheroids and spheres. The Orthographic projection is supported on spheres only.
Uses and applications
Large-scale mapping. Should not be used for areas greater than 1° from the origin if using ArcInfo Workstation (coverages, GRIDs, or TINs). If using ArcMap, shapefiles, rasters other than GRIDs, or geodatabase data, can project almost a full hemisphere (89° from the origin).
Parameters
Desktop
- False Easting
- False Northing
- Longitude of Center
- Latitude of Center
- Scale factor
- Azimuth
Workstation
- Longitude of the origin
- Latitude of the origin