[R-sig-Geo] suggestion for projection

[Kamran Safi]

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


 
-- 
Kamran Safi

Max Planck Institute for Ornithology
Vogelwarte Radolfzell
Schlossallee 2
78315 Radolfzell
Germany

and

Institute of Zoology
Zoological Society of London
Regent's Park
NW1 4RY London
United Kingdom
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