6.3.8 Miller Cylindrical Projections (-Jj -JJ)

This cylindrical projection, presented by O. M. Miller of the American Geographic Society in 1942, is neither equal nor conformal. All meridians and parallels are straight lines. The projection was designed to be a compromise between Mercator and other cylindrical projections. Specifically, Miller spaced the parallels by using Mercator's formula with 0.8 times the actual latitude, thus avoiding the singular poles; the result was then divided by 0.8. There is only a spherical form for this projection. The requirements to define this projection are:

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The central meridian

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The standard parallel

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Scale in inch/degree or as 1:xxxxx (-Jj), or map width (-JJ)

For instance, a world map centered on the 90$^{o}$E meridian at a map scale of 1:400,000,000 can be obtained as follows:

pscoast -R-90/270/-80/90 -Jj90/1:400000000 -B45g45/30g30 -Dc -A10000 -Glightgray -W0.25p -P \
    > GMT_miller.ps

Figure 6.20: World map using the Miller cylindrical projection.