next up previous contents index
Next: Robinson Projection (-–Jn -JN) Up: Miscellaneous Projections Previous: Mollweide Projection (-–Jw -–JW)

Winkel Tripel Projection (–-Jr -–JR)

     

The Winkel Tripel projection, presented by Oswald Winkel in 1921, is a modified azimuthal projection that is neither conformal nor equal-area. Central meridian and equator are straight lines; other parallels and meridians are curved. The projection is obtained by averaging the coordinates of the Equidistant Cylindrical and Aitoff (not Hammer-Aitoff) projections. The poles map into straight lines 0.4 times the length of equator. To use it you must enter

$\bullet$
The central meridian

$\bullet$
Scale along equator in inch/degree or 1:xxxxx (-Jr), or map width (-–JR)

Centered on Greenwich, the example in Figure 5.26 was created by this command:





pscoast -R-180/180/-90/90 -JR0/4.5i -Bg30/g15 -Dc -A10000 -G128 -P >! GMT_winkel.ps






  
Figure 5.26: World map using the Winkel Tripel projection
\begin{figure}\centering\epsfig{figure=eps/GMT_winkel.eps}\end{figure}

     



Paul Wessel
1999-03-25