Hi Guys,
I'm a long time lurker here who usually just hits the search button when I have a question but this time I haven't been able to get the answers I need so here goes.
I have had 3 Promark 2 units for quite a while so I'm familiar with the process of using GPS for control and then processing it with solutions but after talking to a colleague who recently started working with a network rover system I think I may be at the point of leaping into the dual frequency arena. I have a couple of questions though;
1)Can I get any dual frequency receiver and use it as a network rover? This would certainly be an attractive alternative to me seeing that some of the older units are available rather cheaply, enough so that I might have enough left over for a network subscription.
2)From what I have read there is no advantage to using a traditional base-rover setup over the network rover system. Is this correct?
3)I understand why traditional systems fail in wooded and urban areas. This would be the same with networks, right? The rover still needs to pull in the signal from the satellites as well as the corrections over the internet wirelessly?
Thanks in advance for the help.
Ron
Yes And No
From the demoes I have seen it is the controller that is more important.
If you want to get on KeyNetGPS your easiest solution would be a Trimble controller.
If you want to get on SmartNet think Leica controller.
Pick a network, research the controllers then research what receivers work with them. It is possible to work with an outside controller and/or receiver but the work is going to be all yours. The reason for both networks is to help make a sale.
Because of the public/private crossover outside access is doable but not neccessarily simple.
Verify what you get with outside equipment which may be limited to a single base, so it is RTK only. Verify if a VRS solution works with what you want to get. It is possible to improve single base RTK, by switching bases and redoing the observation. That may be cheaper but it definitely consumes more time.
Paul in PA
Yes And No
I would also check that you can actually achieve the accuracy you need with a network solution.
Around here the networks aren't very dense, and the baselines work out long.
The accuracies I am seeing are ok for engineering work, but I would be very cautious using a network or VRS solution for land transfer work.
You can test it easily enough for yourself with repeated measurements to the same known point. The variation you see in the data will give you a feel for the accuracy any single observation.
Your mileage may vary...
Yes And No
I disagree, and this is not true.
Controllers aren't the issue. All you need us an NTRIP software (there are some free ones) that run on many devices and with any data collector software you want to use. You don't need a Trimble or Leica data collector. I've used SurvCE, Arcpad, and some other software using Novatel, Ashtech and other receivers.
As long as you have NTRIP software, access to either Leica or Trimble networks is easy.
"Verify what you get with outside equipment which may be limited to a single base, so it is RTK only."
Not true, I've yet to try a receiver that doesn't use a network correction if you use the correct mount point.
It doesn't matter whether it's Trimble VRS network or a Leica network. The rover can be any brand.
Come on Paul, lets give people good info.
> From the demoes I have seen it is the controller that is more important.
>
> If you want to get on KeyNetGPS your easiest solution would be a Trimble controller.
>
> If you want to get on SmartNet think Leica controller.
>
> Pick a network, research the controllers then research what receivers work with them. It is possible to work with an outside controller and/or receiver but the work is going to be all yours. The reason for both networks is to help make a sale.
>
> Because of the public/private crossover outside access is doable but not neccessarily simple.
>
> Verify what you get with outside equipment which may be limited to a single base, so it is RTK only. Verify if a VRS solution works with what you want to get. It is possible to improve single base RTK, by switching bases and redoing the observation. That may be cheaper but it definitely consumes more time.
>
> Paul in PA
Yes And No
🙂 :good: :good: Great Callout
No Intent To Misslead
My information came from demonstrations, so I was missled by the sales people.
I was unaware of succesful third party users such as you.
Feel free to carry on the conversation with more details.
Paul in PA
No Intent To Misslead
The misleading part is the sales pitch claiming you can jump out of the truck and survey anything with a network rover. Perhaps this is possible in some areas but for my area it's just another tool for certain applications.
OK, some great info so far. So good that I have more questions.
1)So pretty much any unit that could be used as the rover part of a base-rover combo can be used with RTN? If that's true what capabilities should I be looking for specifically when I look on ebay or other places?
2)The way it works is the controller gets the network data and also the raw data from the unit and using the 2 calculates a good position? Where does the NTRIP software come into play? Does the controller have to be matched to the GPS unit or are there generic versions that work with most of the major players?
Re: First part of question 2 -
Unless I have been missing something for the past 20+ years (which is completely possible), the brain work of combining base-receiver/reference data and rover-receiver data to determine the fixed carrier-phase solution is done by the rover receiver.
When using base-receiver/reference data from an internet source (that does not go directly to a GSM module in the rover receiver), the data collector serves as a part of the communication channel that forwards the base-receiver/reference data from the network to the rover receiver, which then works out the solution and sends position (and other) data back to the data collector.
GB