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flatplrp

McBryde-Thomas Flat-Polar Parabolic Projection

Classification

Pseudocylindrical

Identifier

flatplrp

Graticule

Central Meridian: Straight line 0.48 as long as the Equator.

Other Meridians: Equally spaced parabolic curves concave toward the central meridian.

Parallels: Unequally spaced straight parallel lines, perpendicular to the central meridian. Spacing is greatest near the Equator.

Poles: Lines one-third as long as the Equator.

Symmetry: About the central meridian or the Equator.

Features

This is an equal-area projection. Scale is true along the 45º30' parallels and is constant along any parallel and between any pair of parallels equidistant from the Equator. Distortion is severe near the outer meridians at high latitudes, but less so than on the pointed-polar projections. It is free of distortion only at the two points where the central meridian intersects the 45º30' parallels. This projection is not conformal or equidistant.

Parallels

For this projection, only one standard parallel is specified. The other standard parallel is the same latitude with the opposite sign. The standard parallel is by definition fixed at 45º30'.

Remarks

This projection was presented by F. Webster McBryde and Paul D. Thomas in 1949.

Example

landareas = shaperead('landareas.shp','UseGeoCoords',true);
axesm ('flatplrp', 'Frame', 'on', 'Grid', 'on');
geoshow(landareas,'FaceColor',[1 1 .5],'EdgeColor',[.6 .6 .6]);
tissot;

World map using McBryde-Thomas flat-polar parabolic projection

Version History

Introduced before R2006a