Earlier I said:
I don't have the raw files for this yet, but we've been finding that after shooting sets, the data collector inserts incorrect HTs for the BS shot one might take after the set. Of course it reports everything correctly on the screen, just screws up what is supposed to be the record of the survey and what you might use to make an adjustment of yoru field work.
On my first day working with SurvNet I think I have reproduced this issue and have the raw file to show for it. It is not specific to sets, just the BS check routine.
OC,OP102,N 9818.18824,E 10013.35335,EL98.448,--SET MAG&W KDM CONTROL PT
LS,HI5.3800,HR5.4900
BK,OP102,BP213,BS355.4758,BC0.0000
BD,OP102,FP213,AR0.00000,ZE89.29000,SD182.320452,--FD SPK
BR,OP102,FP213,AR179.59550,ZE270.30590,SD182.321764,--FD SPK
--SS,OP102,FP213,AR0.00000,ZE89.29000,SD182.321108,--FD SPK
--Calculated: AR0°00'00", HD182.301, Z100.000
--Measured: AR0°00'00", HD182.314, Z99.982
--Delta: AR0°00'00", HD0.012, Z-0.018
LS,HI5.3800,HR5.2000
SS,OP102,FP301,AR244.2155,ZE88.3007,SD21.948401,--FD L&TK
SS,OP102,FP302,AR309.0936,ZE88.2639,SD23.398199,--FD L&TK
Look Here
--Backsight Check: PT 213
BD,OP102,FP213,AR0.00000,ZE89.29000,SD182.320452,--x
BR,OP102,FP213,AR179.59550,ZE270.30590,SD182.321764,--x
--SS,OP102,FP213,AR0.00000,ZE89.29000,SD182.321108,--x
--Calculated: AR0°00'00", HD182.301, Z100.000
--Measured: AR359°59'55", HD182.314, Z99.983
--Delta: AR0°00'05", HD0.012, Z-0.017
The instrument is moved to 102 and a backsight shot(s) taken to 213.
The BS tripod is set at 5.49
Shots are taken to points 301 and 302.
A Backsight Check is initiated and two readings are recorded to the raw file BD and BR.
Issue 1: These are not true readings, they are merley a copy of what was read the first time the backsight was observed. They are read into SurvNET as observations which I beleive adversely skews the adjustment by adding a redundant reading. Can we get a SurvNet programmer's take on this? The manual explains that all the readings are brought together and reduced to one observation, the wieghting adjusted for multiple readings. I think that doing a few BS checks could overly constrain a reading by having it weighted too highly.
Observation: The true reading is recorded only in a note file and those results presented to the operator. Important to note here that it all looks fine to the operator because the correct BS height exists "on the fly" and is being used for the "check".
Issue 2: The HI line known and required has not been put into the raw file! If you process this raw file the incorrect "redundant" information is now applied with the RodHt of the last point shot, 5.20 in this case.
I noticed this because I was getting a bad error on vertical between 102 and 213. The angles all looked fine, it took me a while to see what was missing. This has happened many times to me initially with 2.x when I was exporting to another LSA program (StarNet) and I thought it might be a conversion error, but since it is happeneing in the raw file it is throwing SurvNet off too.
This is a portion of a raw file from an actual crew working, the entire file is here: http://www.kdmmeridian.com/Linked/08BVT04-081216.rw5
You can look earlier in the file and see it happened again, but it didn't cause a problem because there was a set collected before the BS check and that set happened to end on the BS (just luck it was done that way and not BDBR/FRFD or some other order that doesn't end on the BS).
Is anyone else processing raw data? Do those people use the BS check routine?