Mollweide

Description

Also called Babinet, elliptical, homolographic, or homalographic, Carl B. Mollweide created this pseudo cylindrical projection in 1805. It is an equal-area projection designed for small-scale maps.

Illustration of the Mollweide projection

Projection method

Pseudo cylindrical equal-area projection. All parallels are straight lines, and all meridians are equally spaced elliptical arcs. The exception is the central meridian, which is a straight line. The poles are points.

Linear graticules

The equator and central meridian.

Properties

Shape

Shape is not distorted at the intersection of the central meridian and latitudes 40°44' N and S. Distortion increases outward from these points and becomes severe at the edges of the projection.

Area

Equal area.

Direction

Local angles are true only at the intersection of the central meridian and latitudes 40°44' N and S. Direction is distorted elsewhere.

Distance

Scale is true along latitudes 40°44' N and S. Distortion increases with distance from these lines and becomes severe at the edges of the projection.

Limitations

Useful only as a world map.

Uses and applications

Suitable for thematic or distribution mapping of the entire world, frequently in interrupted form.

Combined with the Sinusoidal to create Goode's Homolosine and Boggs.

Parameters

Desktop

  • False Easting
  • False Northing
  • Central Meridian
NoteNote:

Supported on spheres only.

Mollweide Auxiliary Sphere (Desktop version 9.3 and later)

  • False Easting
  • False Northing
  • Central Meridian
  • Auxiliary Sphere Type
NoteNote:

The Auxiliary Sphere Type parameter accepts 0 (use semimajor axis or radius of the geographic coordinate system), 1 (use semiminor axis or radius), 2 (calculate and use authalic radius), or 3 (use authalic radius and convert geodetic latitudes to authalic latitudes).

Workstation

  • Longitude of projection center
NoteNote:

Supported on spheres only.

Related Topics


7/31/2013