Does anyone know if Trimble Access stores the vector data for VRS RTK? I've never used this data in TBC before, and the only thing coming in is point data. I used the JXL, could I get it if I exported a DC file? So far the control check-ins are amazingly tight, though.
I don't know if Trimble Access caused Trimble to change the output of VRS but it was always points only, no vectors.
Actually (the DC just came back into the office) it looks as if you have to set the survey style to store the QC & Vector data. I guess most people don't store VRS Vector data??? I always want my vectors.
The correct Trimble way with Survey Controller is to always store points only. It gave the option to store vector data but it didn't work as well. It's been 4 or 5 years since it was explained to me but it was something like it transmitted the rover point position to the network, calculated a network position (kinda like OPUS), and transmitted the position back to the rover. If you stored a vector, you were getting a single baseline solution instead of a network solution. That may be an oversimplification and I hope someone will correct me if I'm wrong.
I thought the network solution was a single baseline because you are receiving corrections from one virtual reference station (whose data are modeled by the network)?
In your Survey Style>Rover Options> Store points as, set it to vectors.
They you will have the raw GNSS data.
It IS shown as a single base vector to your nearest physical base. As I understand it, this is a calculated vector.
Your point positon is a calculated from your VRS "station" that is created near you.
Survey Controller or Access work equally well storing points or vectors.
I always recommend storing vectors, so if you need to post process or adjust some data you have something to work with, rather than doing just a coordinate transformation.
I have been doing some research to better understand what I remember being told before but most of it is two to nine years old and things may have changed.
To start out with, I found this in the Survey Controller Manual on trimble.com. “To store VRS vectors to the nearest Physical Base Station (PBS) in the VRS network, the VRS system must be configured to output the PBS information. If the VRS system does not output PBS data, VRS data must be stored as positions.” How do you find out whether a VRS network is configured to output PBS information? I have never been told or given this information. I have used a few VRS GPS networks – Ohio DOT, Indianapolis, Reno, Vancouver, the San Francisco Bay area, maybe a couple of other places – and the standard to store points as positions was always the recommended setting. Is the new standard to have the VRS configured to output PBS? It’s been a couple of years so I’m not completely familiar with any recent changes.
I also found that the VRS calculates a virtual position a few meters from the rover position. If you have your survey style set to store points as vectors and PBS is not being output from the network, will it just calculate a vector from the virtual reference station? Does that reference station move as you move around your project site or does it remain stationary as long as you maintain initialization?
What I would really love to see is SC or Access store/log raw data and the information used in the network solution instead of just a coordinate. I skimmed through several research papers that indicated VRS network solutions are more accurate than single vector solutions. Could you do infill on the rover while performing a VRS RTK survey? That way you could download the CORS data later and “reproduce” your network solution with more redundancy than a single vector.
I don't know about all VRS networks, but in the ones I am familiar with, they all output a Physical Base Positon.
The VRS base is created a few meters from your inital position and then it stays there until you move x distance from that intial position. What distance that is is determined by the VRS server software. Ours is set to 5km, I believe.
I have never seen vectors from the VRS base.....
I do believe you can store raw info on the collector during VRS...in your survey style>rover options>survey type, choose RTK and logging....
What good are vectors from a "virtual" reference station?
Cool. I really appreciate the information.