Show Navigation | Hide Navigation
You are here:
Map projections and coordinate systems > Supported map projections

Eckert IV

Release 9.2
Last modified August 3, 2007
E-mail This Topic Printable Version Give Us Feedback

Print all topics in : "Supported map projections"


Related Topics



Description

This equal area projection is used primarily for world maps.

Illustration of Eckert IV projection


Projection method

A pseudo cylindrical equal-area projection.


Linear graticules

Parallels are unequally spaced straight lines, closer together at the poles. Meridians are equally spaced elliptical arcs. The poles and the central meridian are straight lines half as long as the equator.


Properties


Shape



Shapes are stretched north–south 40 percent along the equator, relative to the east–west dimension. This stretching decreases to zero at 40°30' N and S at the central meridian. Nearer the poles, features are compressed in the north–south direction.

Area



Equivalent.

Direction



Local angles are correct at the intersections of 40°30' N and S with the central meridian. Direction is distorted elsewhere.

Distance



Scale is distorted north–south 40 percent along the equator relative to the east–west dimension. This distortion decreases to zero at 40°30' N and S at the central meridian. Scale is correct only along these parallels. Nearer the poles, features are compressed in the north–south direction.


Limitations

Useful only as a world map.


Uses and applications

Thematic maps of the world, such as climate.


Parameters


Desktop





Workstation





Please visit the Feedback page to comment or give suggestions on ArcGIS Desktop Help.
Copyright © Environmental Systems Research Institute, Inc.