Albers Equal Area Conic Projection

 

World Map

Albers Equal Area Conic Projection

Central Longitude: 0

Central Latitude: 0

Standard Parallel: 45

2nd Standard Parallel: 0

 

Projection Characteristics

The Albers Equal Area Conic projection scale is constant along any given parallel and accurate along the two specified standard parallels. This projection is used in the National Atlas of the United States. The Albers Equal Area Conic projection is useful for equal area maps of low-aspect regions (regions that are wider than they are tall).

 

Projection Parameters

Parameter

Description

Name

Specifies the units used in the map.

Scale

Specifies the unit scale of the projected map, relative to meters. For example, a scale of one means one unit in the projected map equals one meter; a scale of two means two units in the projected map equal one meter; etc.

False Easting

Specifies the false easting, or horizontal offset, of the projected coordinates, in meters. False Eastings and False Northings are added to the underlying "projected" coordinates as a way to arbitrarily offset their internal XY coordinates after the projection. Unless you have a reason for using these offset values, do not use them. These values do not affect the latitude/longitude coordinates for the map, only the internal coordinates used to plot the map on the screen. If you use False Easting and False Northing offsets for a map, any subsequent boundaries you append to the map must also use these same offsets if you want the imported boundaries to be drawn in the correct relative position to the existing boundaries.

False Northing

Specifies the false northing, or vertical offset, of the projected coordinates, in meters. See above.

Central Longitude

Specifies the central longitude of the projection in degrees. The Central Longitude value typically should be defined as the longitudinal center of the map you are going to produce. For example, the value -95.5 represents the geographic center of the United States, so the map of the U.S. is drawn upright.

Central Latitude

Specifies the central latitude of the projection in degrees. The Central Latitude value should be defined as the latitudinal center of the map you are going to produce. This value is only significant when you define False Easting and False Northing values.

Standard Parallel

Specifies the latitude of the first of two standard parallels, in degrees. The standard parallels typically are defined at approximately one-sixth of the distance inside the north and south limits of the map. For example, if your map latitude ranges from 30° to 36°, you could place your Standard Parallels at 31° and 35°. There are alternative methods for determining the best position of the standard parallels. Please see Snyder for more information.

2nd Standard Parallel

Specifies the latitude of the second of two standard parallels, in degrees. See above.

 

 

See Also

Map Coordinate Systems Overview

Introduction to Map Projections

Source Coordinate System - Map Layer

Target Coordinate System - Map

Types of Projection

Characteristics of Projections

Datums

Ellipsoids

Projection References