Lambert Conformal Conic¶
A Lambert Conformal Conic projection (LCC) is a conic map projection used for aeronautical charts, portions of the State Plane Coordinate System, and many national and regional mapping systems. It is one of seven projections introduced by Johann Heinrich Lambert in 1772.
It has several different forms: with one and two standard parallels (referred to as 1SP and 2SP in EPSG guidance notes). Additionally we provide "2SP Michigan" form which is very similar to normal 2SP, but with a scaling factor on the ellipsoid (given as k_0 parameter). It is implemented as per EPSG Guidance Note 7-2 (version 54, August 2018, page 25). It is used in a few systems in the EPSG database which justifies adding this otherwise non-standard projection.
Classification |
Conformal conic |
Available forms |
Forward and inverse, spherical and ellipsoidal .
One or two standard parallels (1SP and 2SP).
"LCC 2SP Michigan" form can be used by setting
|
Defined area |
Best for regions predominantly east–west in extent and located in the middle north or south latitudes. |
Alias |
lcc |
Domain |
2D |
Input type |
Geodetic coordinates |
Output type |
Projected coordinates |
proj-string: +proj=lcc +lon_0=-90 +lat_1=33 +lat_2=45¶
Parameters¶
Required¶
- +lat_1=<value>¶
First standard parallel.
Defaults to 0.0.
Note
The default convention is to interpret this value as decimal degrees. To specify radians instead, follow the value with the "r" character.
Example: +lat_1=1.570796r
See Projection Units for more information.
Optional¶
- +lon_0=<value>¶
Central meridian/longitude of natural origin, longitude of origin or longitude of false origin (naming and meaning depend on the projection method).
Defaults to 0.0.
Note
The default convention is to interpret this value as decimal degrees. To specify radians instead, follow the value with the "r" character.
Example: +lon_0=1.570796r
See Projection Units for more information.
- +lat_0=<value>¶
Latitude of natural origin, latitude of false origin or latitude of projection centre (naming and meaning depend on the projection method).
Defaults to 0.0.
Note
The default convention is to interpret this value as decimal degrees. To specify radians instead, follow the value with the "r" character.
Example: +lat_0=1.570796r
See Projection Units for more information.
- +lat_2=<value>¶
Second standard parallel.
Defaults to 0.0.
Note
The default convention is to interpret this value as decimal degrees. To specify radians instead, follow the value with the "r" character.
Example: +lat_2=1.570796r
See Projection Units for more information.
- +ellps=<value>¶
The name of a built-in ellipsoid definition.
See Ellipsoids for more information, or execute
proj -lefor a list of built-in ellipsoid names.Defaults to "GRS80".
- +R=<value>¶
Radius of the sphere, given in meters. If used in conjunction with
+ellps,+Rtakes precedence.See Ellipsoid size parameters for more information.
- +x_0=<value>¶
False easting, easting at false origin or easting at projection centre (naming and meaning depend on the projection method). Always in meters.
Defaults to 0.0.
- +y_0=<value>¶
False northing, northing at false origin or northing at projection centre (naming and meaning depend on the projection method). Always in meters.
Defaults to 0.0.
- +k_0=<value>¶
This parameter can represent two different values depending on the form of the projection. In LCC 1SP it determines the scale factor at natural origin. In LCC 2SP Michigan it determines the ellipsoid scale factor.
Defaults to 1.0.