I'm no expert here but I poked around spatialrefernce.org a bit and found some stuff that might get you going in the right direction.
North American Equidistant Conic http://spatialreference.org/ref/esri/102010/ South American Equidistant Conic http://spatialreference.org/ref/esri/102032/ Any chance you could run the study using great circle distances, there is support for such distance measuring in R using spDistsN1 in the sp package. That way all you'd have to do is pick a spheroid to standardize on. Alex Kamran Safi wrote: > Dear list, > > I am in search of a good projection with which I could run habitat > utilization models on a continental scale. The projection I am looking > for should preserve distances between points as good as possible and the > map units should be meters. I think from what I have explored so far > from the implementations of movement in habitat use models, preserving > distance is the most important factor. Most solutions I found ready made > were fine if you are working on a small scale of a few hectares or even > a couple of square kilometers. The projection I am looking for should > optimize "truth" in distances and be in meters (at least for the time > being) for almost all of North-America and large stretches of > South-America. I am aware that there is no single real solution out > there for this large area, but there should be some projections with a > minimal amount of error given the extent (so to speak an optimum). I > quite often used spTransform, but never dealt with other things than > longlat into moll or aitoff sometimes in utm and vice versa. I have no > experience whatsoever with map units (and wouldn't know how to set or > change them), as this wasn't an issue up to now, and only scratched the > surface of oblique projections (sorry I am a biololgist in the first > place trying to avoid making all too many mistakes in geography). I > appreciate some expert opinion on this. > > The bbox (in longlat) of the area for which I am looking for a good > projection is: min max > x1 -127.2 -46.8 > x2 -19.7 48.6 > > Many thanks in advance, > > Kami > > > > > ------------------------------------------------------------------------ > > _______________________________________________ > R-sig-Geo mailing list > [email protected] > https://stat.ethz.ch/mailman/listinfo/r-sig-geo _______________________________________________ R-sig-Geo mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
