| Mapping Toolbox | |
Syntax
Graticule
Meridians: Equally spaced straight lines converging at one of the poles.
Parallels: Equally spaced concentric circular arcs.
Poles: Arcs, one of which might become a point in the limit.
Features
This is an equidistant projection that is minimum-error. Scale is true along any meridian and is constant along any parallel. Scale is also true along two standard parallels. These must be calculated, however (see below). The total area of the mapped area is correct, but it is not equal-area everywhere.
Parallels
The parallels for this projection are not standard parallels, but rather limiting parallels. The special feature of this map, correct total area, holds between these parallels. The default parallels are [15 75].
Remarks
Described by Patrick Murdoch in 1758, with errors corrected by Everett
in 1904.
Limitations
This projection is available for the spherical geoid only. Longitude data greater than 135° east or west of the central meridian is trimmed.
| | Murdoch I Conic Projection | Orthographic Projection | |
