Question

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

Answer 1

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!) .