hmurray at megapathdsl.net
Sun Nov 30 16:49:39 EST 2014
eb4apl at cembreros.jazztel.es said:
> Do not trust Google Earth data for any precision work. The mentioned six
> feet are probably due to the geographical data, not to the precission of
> your GPS unit. If you look for image seams you can verify the kind of
> errors involved.
How good are USGS topo maps for this sort of thing? Most streets are shown
as a pair of parallel lines, but the separation of the lines doesn't match
the actual width of most streets. Does the center of that pair on the paper
correspond to the center of the road? Can I use the intersection of a pair
of streets as a reference point? ...
How about equivalent maps for other countries?
How well do typical benchmarks agree with GPS?
Are the surveyors maps used for deeds useful in this context?
These are my opinions. I hate spam.
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