5.3.1 Lambert Azimuthal Equal-Area (-–Ja -–JA)

This projection was developed by Lambert in 1772 and is typically used for mapping large regions like continents and hemispheres. It is an azimuthal, equal-area projection, but is not perspective. Distortion is zero at the center of the projection, and increases radially away from this point. To define this projection in GMT you must provide the following information:

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Longitude and latitude of the projection center

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Scale as 1:xxxxx or as radius/latitude where radius is distance on map in inches from projection center to an oblique latitude (-–Ja), or map width in inches (-JA).

Two different types of maps can be made with this projection depending on how the region is specified. We will give examples of both types.