A couple of times while using MoDOT reference station network I have noticed something. Can anyone tell me why after connecting to the network and then tying a few hard points on the ground and then disconnecting and connecting right back I would be off a couple tenths in checking right back into the same points? Note points are in open sky.
Surveyor In Training, post: 337773, member: 10308 wrote: A couple of times while using MoDOT reference station network I have noticed something. Can anyone tell me why after connecting to the network and then tying a few hard points on the ground and then disconnecting and connecting right back I would be off a couple tenths in checking right back into the same points? Note points are in open sky.
Just some thoughts...are you really on the ground? Did you hit "here" at some point and then return to "Grid"? Fix vs. Float solution when observation was stored? Was the RMS high? Check your PDOP for the shot. Open sky does not always guarantee goodness.
I use MODOT network daily and have no such problem, even the StL City - in the 0.10' department. In fact yesterday I shot in new control for 180 epochs, came back shot them again 3 hrs later. I averaged the shots in the collector. Pulled the coords up and keyed them in my TS. Setup, backsight, HD= 0.019' VD = 0.034' I turned in point "B" that was under some trees with two rounds of flopping the scope. Moved to point "B" and checked an independent GPS point "C" HD = 0.01 by VD = 0.02.
Good enough for topo. And we're off...
N10,000, E7,000, Z100.00
PLS - IL, MO, AR, KS, MN, KY
It's only happened to me twice. It's like there is a shift of a tenth or so.
It was actually on one of my control points I set so I could set up my total station. I set the control points then disconnected from the network. Shot a couple points with TS then reconnected to the network. I always like to check into a couple points after reconnecting and usually I am flat in a check. But not this time. Same procedures as always.