# 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 elliptical projection. One or two standard parallels (1SP and 2SP). “LCC 2SP Michigan” form can be used by setting +k_0 parameter to specify elliposid scale. 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.

### Optional¶

+lon_0=<value>

Longitude of projection center.

Defaults to 0.0.

+lat_0=<value>

Latitude of projection center.

Defaults to 0.0.

+lat_2=<value>

Second standard parallel.

Defaults to 0.0.

+ellps=<value>

See proj -le for a list of available ellipsoids.

Defaults to “GRS80”.

+R=<value>

Radius of the sphere given in meters. If used in conjunction with +ellps +R takes precedence.

+x_0=<value>

False easting.

Defaults to 0.0.

+y_0=<value>

False northing.

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.