Hello. I am new to ArcMap and am wondering what transformation is recommended to preserve distance for GCS_WGS_1984?
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I don't have the exact answer, but can provide the projection type likely to be used:
Equidistant projections preserve distances, but no projection can preserve distances from all points to all other points. Instead, distance can be held true from one point (or a few points) to all other points or along all meridians or parallels. If you will be using your map to find features that are within a certain distance of other features, you should use an equidistant map projection.
Source: ArcGIS Desktop Help 9.3 - what is a map projection?
Adding Melita Kennedy to this thread.
Chris Donohue, GISP
Thank you Chris. I need to read up on equidistant projections. Interesting stuff and thank you posting and helping me find my way (no pun intended : ) Very Helpful.
I will add, that if the distances are not too huge (ie within about +/- 3 degrees of your location) you can get away with a "compromise" projection like a UTM etc which tries to preserve distance, direction and area as best it can. No projection is going to preserve everything. You can google UTM (Universal Transverse Mercator) for details about the projection. In the US, I think you also use the Albers and State Plane systems as well
UTM or state plan probably not great but an albers (or even lambert conformal conic) are used often in the U.S
Thank you Dan, for pointing out some equidistant projections to take a closer look at. I will read up on the Albers, Lambert Conformal Conic ---as well as UTM and State Plane systems. Very interesting, the science behind choosing the right projection for your data. Very helpful : )
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