[Proj] NAD 27 v 83 Distances

support.mn at elisanet.fi support.mn at elisanet.fi
Sun Oct 3 12:59:20 EST 2010


1) first of all do you need the length of the ellipsoid arc or the length of the straight line?
- arc is always longer than the straight line between two points

2) if you are using the arc, do you adjust for the height difference of the two places?

3) or maybe you use the length of the arc between the points projected on the reference
ellipsoids? or yet the straight line?

etc. etc.



Robert McFaul [robert at dgi.com] kirjoitti: 
> Hi,
> I'm concerned about whether ground surface distances are different between
> NAD27 and NAD83. I'm in California (southern) and thinking about a 
> conversion
> of a project to NAD83. I have some cross section distances measured (1000 to
> 3000 feet in length) and suddenly am wondering what sort of differences 
> might
> be involved by this change in systems.
> What can I expect here?
> Thanks.
> robert mcfaul
> robert at dgi.com
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