ArcGIS Help 10.1 - McBryde-Thomas Flat-Polar Quartic

Description

This equal-area projection is primarily used for world maps.

Illustration of the McBryde-Thomas flat-polar quartic projection

Projection method

A pseudo cylindrical equal-area projection in which all parallels are straight lines and all meridians, except the straight central meridian, are equally spaced, fourth-order (quartic) curves.

Linear graticules

All parallels are unequally spaced straight lines that are closer together at the poles. The poles are straight lines one-third as long as the equator. The central meridian is a straight line 0.45 times as long as the equator.

Properties

Shape

Shapes are stretched north–south along the equator, relative to the east–west dimension. This stretching decreases to zero at 33°45' N and S at the central meridian. Nearer the poles, features are compressed in the north–south direction.

Area

Equal area.

Direction

Distorted except at the intersection of 33°45' N and S and the central meridian.

Distance

Scale is distorted everywhere except along 33°45' N and S.

Limitations

Useful only as a world map.

Uses and applications

Thematic maps of the world.

Parameters

Desktop

False Easting
False Northing
Central Meridian

Note:

Supported on spheres only.

geographic_coordinate_systems.pdf	A geographic coordinate systems pdf file which contains lists of supported gcs and vcs.
projected_coordinate_systems.pdf	A projected coordinate systems pdf file which contains lists of supported pcs.
geographic_transformations.pdf	A geographic transformations pdf file which contains lists of supported geographic and vertical transformations.

Workstation

Longitude of projection's center