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Does the Proj4JS library support the Gall-Peters projection? I can't seem to find a projection acronym for it?

winwaed
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The code you are looking for is "cea" for Cylindrical Equal Area.

The actual definition will be:

"+proj=cea +lon_0=0 +x_0=0 +y_0=0 +lat_ts=45 +ellps=WGS84 +datum=WGS84 +units=m +no_defs"

Change the value of lat_ts to 44.138 for the strict Peter projection, although as your title implies, the Gall and Peters projections are virtually the same (I won't get into *that * political argument, thank you!).

Some prefer the Behrman which is similar but with a lat_ts of 30. This produces less distortion of the equatorial regions (something Peters was claiming he was trying to fix!) .

winwaed
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  • How does that compare with the Proj4JS format from: http://spatialreference.org/ref/sr-org/6838/ They are slightly different values. – Mike Gifford Apr 13 '12 at 04:48
  • 6838 appears to use the CEA projection, but as far as I can tell, it is not the Gall-Peters projection. It looks like it is used for a specific need because the meridian (longitude 0) is significantly different too. – winwaed Jun 24 '15 at 01:36