0

I am working on a map of South America (from the top of Chile down to Cape Horn; everything south of 18S). I need to include distance buffers on my map but I am getting confused by which projection to use to get the distance right.

Would Plate Carree work or is there a better one for this area?

1

No projection is natively going to give you the correct distances unless you are measuring very particular lines, like from the center of a azimuthal equidistant projection.

If the area of interest is relatively small, a projected coordinate reference system (CRS) that's conformal (maintains local angles/shapes) or equal area may give 'good enough' results.

Some software tools or workflows may have the capability to return geodesic-based distances instead. Geodesic distances are based on the surface of the ellipsoid so still not 100% correct relative to the topography, but often good enough versus 2D Cartesian distances based on a projected CRS.

For half of South America, you could make a custom equidistant cylindrical projection. That would have accurate north-south distances and the distances along the standard parallels would be accurate. Use SIRGAS for the geographic CRS.

0

Follow this link to find the zone of your study area https://www.e-education.psu.edu/natureofgeoinfo/c2_p22.html

-1

Try the projected coordinate system Peru96_UTM_Zone_17S. If that doesn't appear accurate try Peru96_UTM_Zone_18S and Peru96_UTM_Zone_19S. I hope this helps.

  • 1
    Peru is north of Chile so I don't think ProjCRS based on Peru96 are appropriate. – mkennedy Apr 1 at 20:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.