Chamberlin Trimetric

Classification	Miscellaneous
Available forms	Forward spherical projection
Defined area	Global
Alias	chamb
Domain	2D
Input type	Geodetic coordinates
Output type	Projected coordinates

proj-string: +proj=chamb +lat_1=10 +lon_1=30 +lon_2=40

Parameters

Required

Note

Control points should be oriented clockwise.

+lat_1=<value>

Latitude of the first control point.

+lon_1=<value>

Longitude of the first control point.

+lat_2=<value>

Latitude of the second control point.

+lon_2=<value>

Longitude of the second control point.

+lat_3=<value>

Latitude of the third control point.

+lon_3=<value>

Longitude of the third control point.

Optional

+lon_0=<value>

Longitude of projection center.

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=1.5708r

See Projection Units for more information.

+R=<value>

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

See Ellipsoid size parameters for more information.

+x_0=<value>

False easting.

Defaults to 0.0.

+y_0=<value>

False northing.

Defaults to 0.0.