Projection Specifications

GMT offers 31 map projections. These are specified using the -J common option. There are two conventions you may use: (a) GMT-style syntax and (b) PROJ-style syntax. The projection codes for the GMT-style and the PROJ-style are tabulated below.

GMT PROJECTION CODES

PROJ PROJECTION CODES

-J (upper case for width, lower case for scale)

-J (lower case for scale only)

-JAlon0/lat0[/horizon]/width

-Jlaea/lon0/lat0[/horizon]/scale

Lambert azimuthal equal area

-JBlon0/lat0/lat1/lat2/width

-Jaea/lon0/lat0/lat1/lat2/scale

Albers conic equal area

-JClon0/lat0/width

-Jcass/lon0/lat0/scale

Cassini cylindrical

-JCyl_stere/[lon0[/lat0/]]width

-Jcyl_stere/[lon0[/lat0]/]scale

Cylindrical stereographic

-JDlon0/lat0/lat1/lat2/width

-Jeqdc/lon0/lat0/lat1/lat2/scale

Equidistant conic

-JElon0/lat0[/horizon]/width

-Jaeqd/lon0/lat0[/horizon]/scale

Azimuthal equidistant

-JFlon0/lat0[/horizon]/width

-Jgnom/lon0/lat0[/horizon]/scale

Azimuthal gnomonic

-JGlon0/lat0[/horizon]/width

-Jortho/lon0/lat0[/horizon]/scale

Azimuthal orthographic

-JGlon0/lat0/alt/azim/tilt/twist/W/H/width

-Jnsper/lon0/lat0/alt/azim/tilt/twist/W/H/scale

General perspective

-JH[lon0/]width

-Jhammer/lon0/scale

Hammer equal area

-JI[lon0/]width

-Jsinu/lon0/scale

Sinusoidal equal area

-JJ[lon0/]width

-Jmill/lon0/scale

Miller cylindrical

-JKf[lon0/]width

-Jeck4/lon0/scale

Eckert IV equal area

-JKs[lon0/]width

-Jeck6/lon0/scale

Eckert VI equal area

-JLlon0/lat0/lat1/lat2/width

-Jlcc/lon0/lat0/lat1/lat2/scale

Lambert conic conformal

-JM[lon0[/lat0]/]width

-Jmerc/[lon0[/lat0/]]scale

Mercator cylindrical

-JN[lon0/]width

-Jrobin/[lon0/]scale

Robinson

-JOalon0/lat0/azim/width[+v]

-Jomerc/lon0/lat0/azim/scale[+v]

Oblique Mercator, 1: origin and azim   

-JOblon0/lat0/lon1/lat1/width[+v]

-Jomerc/lon0/lat0/lon1/lat1/scale[+v]

Oblique Mercator, 2: two points

-JOclon0/lat0/lonp/latp/width[+v]

-Jomercp/lon0/lat0/lonp/latp/scale[+v]

Oblique Mercator, 3: origin and pole

-JPwidth[+a][+f[e|p|radius]][+roffset][+torigin][+z[p|radius]]

-Jpolar/[+a][+f[e|p|radius]][+roffset][+torigin][+z[p|radius]]

Polar [azimuthal] (\(\theta, r\)) (or cylindrical)

-JPoly[lon0[/lat0]/]width

-Jpoly/[lon0[/lat0/]]scale

(American) polyconic

-JQ[lon0[/lat0/]]width

-Jeqc/[lon0[/lat0/]]scale

Equidistant cylindrical

-JR[lon0/]width

-Jwintri/[lon0/]scale

Winkel Tripel

-JSlon0/lat0[/horizon]/width

-Jstere/lon0/lat0[/horizon]/scale

General stereographic

-JT[lon0[/lat0]/]width

-Jtmerc/[lon0[/lat0/]]scale

Transverse Mercator

-JUzone/width

-Jutm/zone/scale

Universal Transverse Mercator (UTM)

-JV[lon0/]width

-Jvandg/[lon0/]scale

Van der Grinten

-JW[lon0/]width

-Jmoll/[lon0/]scale

Mollweide

-JXwidth[l|pexp|T|t][/height[l|pexp|T|t]][d]

-Jxyxscale[l|pexp|T|t][/yscale[l|pexp|T|t]][d]

Linear, log\(_{10}\), \(x^a-y^b\), and time

-JYlon0/lat0/width

-Jcea/lon0/lat0/scale

Cylindrical equal area