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## 6.2.1 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:

- Longitude and latitude of the projection center.
- Optionally, the horizon, i.e., the number of degrees from the center to the edge (180°, default is 90°).
- Scale as 1:xxxxx or as radius/latitude where radius is the projected distance on the map from projection center to an oblique latitude (-Ja), or map width (-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.

Subsections

- 6.2.1.1 Rectangular map
- 6.2.1.2 Hemisphere map

Next: 6.2.1.1 Rectangular map Up: 6.2 Azimuthal projections Previous: 6.2 Azimuthal projections Contents Index