Hi,
In order to determine the precision of a level run it is necessary to know the distance, as in the formula C = 12 root K, where K is in kilometres. This distance is the accumulated sighting distances, not the direct distance between control points.
But what if you don't know the distance and you don't want to read stadia lines, how can you determine the precision? :-S
SS
It is not necessary to know the length of the loop to some high degree of precision. Measuring it by pacing or by vehicle odometer would suit most purposes. Failing that, you could assume that each BS to FS pairing covered a certain distance. 400-500 feet might be a good assumption.
And failing all that, define your precision in terms of turning points rather than distance.
Google Earth could be used to produce the distance in many circumstances, but the original post begs the question: if you're really interested in quantifying the estimated accuracy, why aren't you following well-established procedures for doing so?
:good:
True, C = 12 root K is a statement of error tolerance and not a measure of precision.
Norman,
Thanks for pointing that out. I should have said "error tolerance" as I think I've misled some people. The terrain doesn't permit vehicles and is steep and dense with trees, which rules out gps. Pacing is probably my only option for determining a rough distance, and I'll look for a formula for distributing the misclose per number of setups. Thanks for your input.
Jim and John,
I am following the procedures of precise levelling, but thank you for your input. :good:
read three wires, gives you your distance for each turn and doesn't take all that much more time. So much easier than pacing and trying to keep track of that.
MightyMoe
I will probably ask my assistant to pace where the ground is level, then I'll stadia the very steep sections.
Thanks for your help.
