A second set of eyes>>VH
older 'boy' would lie about it, instead of braggin' 🙂
"Cape Cod boys ain't go no sleds
They slide down hills on cod fish heads"
A second set of eyes>>VH
> "Cape Cod boys ain't go no sleds
> They slide down hills on cod fish heads"
I kinda' think someone told them Cape Cod boys that them sleds were 'codpieces
Sorry getting a little too far off-tangent now....
Traverse Point 18 Appears To Be The Problem
Using the perpendicular offset from the 1-20 and 2-21 both pointed to theiddle of line 7-8. So the common quick and easy way did not work.
I was surprised by how close 20 was to 1 0.15' and 21 was to 2 0.25'. Seeing that 0.15' I know a lot of surveyors that would stop right there and call it good. What bothered me was the 1'37" angular error and the angle wedge was pointing North. I started at TP 15 as suggested since it was acute and used my radial stakeout routine, backsighting 21 and staking out 21, 2, 20, 1 and looked at the differnce in the stakeout angles, then I sat on 17, 18 and 19. I found what I was looking for the difference from 21 to 2 was 1'27" and the difference from 20 to 1 was 1'26". That is almost all the angular closure error.
If I rotate polyline 18-19-20-21 that amount at point 18 the closure from 20 to 1 is the magical 0.04' and from 21-2 it is even better 0.02'. Placing that polyline on points 1 to 2 also gives that 0.04' closure at 18. Another reason to look at 18 is it has the shortest combination of BS/FS of all the TPs. I note that boundary point 122 was located from 18, only 2° right from 17 so it may be possible to observe it from 17. I suggest reobserving at 17, 18 and 19 with double the D&Rs and a tie or two. The reason the boundary seemed so close is that almost all the traverse error was after 90% of the traverse was run.
This problem required a slightly ifferent way of looking at the data and the problem although one should always be concerned with short sights.
Paul in PA
This is one of the problems with data collection. You should be looking at the double angle to see if it is within the equipment specs., and if not you turn it again and not record it. There is a formula for this but rule of thumb would be twice the least count or spec. of the gun. If you have a 5 second gun the double should be within 10 of the first.