In theory, yes. In practice, maybe. You would find that if you did a third measuring line, it probably wouldn't intersect where the first two did. Small errors at the measuring end cause massive errors at the other end. Even the guys with the specialist measuring equipment working on a building site can have trouble.
It's all about levers. If your first two known points are say 100 meters apart, and the object you're trying to measure is 2,000 meters away, a five meter sideways error at this end on one of the points (an easy error with a GPS) would cause a 400 meter variation at the other end. Which means if you want to do this, you need to do the following. 1) More than two lines. Three minimum, more is better. Also come from as wide an angle as possible. 2) Get your two known points as far apart as you can. If your telepone pole is halfway between you and your target, then the errors at the other end are the same as the errors at your end. 3) Make sure you mark the target source as not by GPS (maybe source=triangulation?) Stephen 2008/5/13 Jeffrey Martin <[EMAIL PROTECTED]>: > I couldn't find the other thread on this topic. > > How do you map an object, like a tower on top of a mountain, that > you don't have access to without expensive survey equipment? > > My thought is to use a plumb bob to line up the unknown object > with some known objects. I would find something like a phone > pole between me and the mountain tower. I would move along > a road until the pole and the tower line up. Now I have a straight > line. Do it again with another strait line and I have two lines > to define the location. > > Would that work? > > -- > http://bowlad.com > > _______________________________________________ > talk mailing list > talk@openstreetmap.org > http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk > _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
