Description
This projection shows the true distance from either of two chosen points to any other point on a map.
Projection method
Modified planar.
Points of contact
None.
Linear graticules
Normally none.
Properties
Shape
Minimal distortion in the region of the two chosen points, if they're within 45° of each other. Increasing distortion beyond this region.
Area
Minimal distortion in the region of the two chosen points, if they're within 45° of each other. Increasing distortion beyond this region.
Direction
Varying distortion.
Distance
Correct from either of two chosen points to any other point on the map. Straight line from either point represents the correct great circle length but not the correct great circle path.
Limitations
Does not represent great circle paths.
Uses and applications
Used by the National Geographic Society for maps of Asia.
Adapted form used by Bell Telephone system for determining the distance used to calculate long distance telephone rates.
Parameters
Desktop
- False Easting
- False Northing
- Latitude of 1st point
- Latitude of 2nd point
- Longitude of 1st point
- Latitude of 2nd point
Workstation
- Longitude of point A
- Latitude of point A
- Longitude of point B
- Latitude of point B