VRS data source selection
Can any one explain what the difference is between these options?
- 6 Replies
Your simple question could uncover a multitude of sins, but as a start…
VRS systems can contain more than one real base station.
They can also generate a virtual computed (average if you like) base station using the real ones.
Depending on your software configuration, you might be presented a list of stations – both real and virtual.
That list is often ordered in distance from you.
You will generally get most accurate results using the nearest base.
Some surveyors do not like the virtual stations and stick only to using real bases.
You can also look at which constellations are tracked – you can only use those common to both the base and rover.
And then we get the format in which the corrections are delivered.
The more you go into it, more complicated it gets. YMMV as they say
What equipment? What software? What RTN? What correction protocol? What rover configuration?
…what are you trying to do?
“…people will come to love their oppression, to adore the technologies that undo their capacities to think.” -Neil Postman
Thanks for the replies
Equipment: Trimble R10 Model1
Software: Access 2016.03
RTN: WVDOT Realtime Network
Correction Protocol: I’ve always been directed to choose VRSCMRX
Choosing that I usually get a virtual base near me. I have tried others and it seems to use the nearest cors but the coordinates of the cors differ slightly. I guess this would be a better option if I was planning to do an adjustment with TBC.
Some options have under the solution column: single base or network
Some options have under the Generator column: Trimble Net R5 or Trimble Pivot Platform
I was really just playing around with it, I’ve been called a button pusher a few times in my career lol, but I hate to just always do the same thing not knowing why.
Cameron M. NicholasCorrection Protocol: I’ve always been directed to choose VRSCMRX
That’s usually the right one for most Trimble RTNs. Around here we choose VRS RTCM because the RTCM is open-source format and receivers other than Trimble can use the network too.
In this mode you might see both network and single-base solutions, or maybe only one or the other. That all depends on how the network operators are configuring things.
Choosing that I usually get a virtual base near me.
In Access you will typically see the virtual reference station, but in post-processing with TBC you might very well see much longer vectors to the nearest physical reference station. Functionally speaking they are the exact same thing, but tying to a reference station makes it far easier to do adjustments and produce standardized products. I personally hate having tons of virtual stations representing nothing at all in the project area.
This also depends on how the network operators have configured the software, but generally speaking with Trimble Pivot RTNs the PRS position is being broadcast and thus your vectors will be tied to them.
This is, of course, assuming that you have selected Store Vectors instead of Store Points in the survey style.
I have tried others and it seems to use the nearest cors but the coordinates of the cors differ slightly.
That’s a bit concerning, even when switching back and forth between network and single-base solutions the reference station broadcast positions should be the same…might warrant some testing to check results between the two.
Some options have under the solution column: single base or network
Generally speaking, network is what you want for most work, since it does a better job of modelling atmospheric errors even when you are not close to any particular station.
Single-base solutions can be used if you are within typical base-rover RTK range, but are subject to the same scalar errors that a base-rover setup would be.
Some options have under the Generator column: Trimble Net R5 or Trimble Pivot Platform
Most likely the first corresponds to a single-base solution (coming directly from the reference antenna) and the second to the network solution (multiple stations are sending info to the Pivot software on a central server, which then crunches all the data and then sends it to your rover).
“…people will come to love their oppression, to adore the technologies that undo their capacities to think.” -Neil Postman
Use a source that gives you a base of a real CORS. A virtual base does you no good in TBC because that??ll result in unconnected sub network errors
Thanks Rover83 that totally answered my question.
The option with vectors from a a base of the actual cors was definately what I was shooting for also.
Cameron M. Nicholas
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