[OSM-newbies] Measuring angles from two positions sufficient to give location?

[Thomas Wood]

Also be aware that if using this to map things, the projection of the
map plays a very important role. Not all projections preserve angle or
distance as you'd expect.

On 25/05/2009, Bill Ricker <bill.n1vux at gmail.com> wrote:
>> > Given this information, can I tell the positions of A, B, and C?
>
>> Yes:
>
> correct.  each of your three measured angles determines a circle
> through the two known points. Where the three circles intersect, is
> where you are.
>
> Typically the three arcs don't quite intersect in an exact point, so
> the triangle formed by the three intersections is the probable region.
> The slightest error in angular measure shifts both the center and
> radius of the circle produced, so this requires high precision for
> precise results.
>
> This probable triangle is a more obvious uncertainty than taking
> bearings TO X from A and B, whence the region of uncertainty resulting
> from the error of measurements is non-obvious, and balloons in range
> behind the most likely point as baseline shrinks in comparison to
> range.
>
>
> --
> Bill
> n1vux at arrl.net bill.n1vux at gmail.com
>
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>


-- 
Regards,
Thomas Wood
(Edgemaster)