Lambert equal-area conic
Parameters: Latitude of origin, Standard parallel 1
Geocart menu class: Conic
Meridians: Equally spaced straight lines converging at a common point, which is one of the poles. The angles between them are less than the true angles.
Parallels: Unequally spaced concentric circular arcs centered on the pole of convergence of the meridians. The meridians are therefore radii of the circular arcs. Spacing of parallels decreases away from the pole of convergence.
Poles: One pole is a point; the other pole is a circular arc enclosing the same angle as that enclosed by the other parallels of latitude for a given range of longitudes. Symmetry: About any meridian
True along the chosen standard parallel
Scale is constant along any given parallel. The scale factor at any given point along the meridian is the reciprocal of that along the parallel, to preserve area.
Free of scale and angular distortion only along the standard parallel. Severe stretching near each pole. Scale distortion and angular distortion are constant along any given parallel.
Presented by Johann Heinrich Lambert (1728 – 1777) of Alsace in 1772
Polar Lambert Azimuthal Equal-Area projection, if the central pole is the standard parallel. The cone of projection thereby becomes a plane.
Albers Equal-Area Conic projection also has concentric circular arcs for parallels and straight meridians, but it has two standard parallels close to the latitudes of interest. If just one of its standard parallels is made a pole, it becomes the Lambert Equal-Area Conic projection, but that pole is not free of distortion, as the usual standard parallel is.
Description adapted from J.P. Snyder and P.M. Voxland, An Album of Map Projections, U.S. Geological Survey Professional Paper 1453. United States Government Printing Office: 1989.