I would like to get opinions on the two VRS networks that cover south Florida.
Trimble VRS now and eGPS.
How well does each work? Reliability? Accuracy?
Has anyone used eGPS with Trimble gear? It should work fine, but are there any issues?
My only experience with VRS is in PA using Keynet (Trimble), which works great. The accuracy issue would depend on the system operator, how tight they have their network setup, how accurate their reference receivers are with respect to the NSRS. If the reference station coordinates are not super accurate, then the results at the rover end are going to reflect that.
I have used eGPS with Trimble gear all over Georgia. I used to work at Travis Pruitt and Associates which is the parent company Of eGPS.
The network was very dependable. E GPS was very well staffed and if there were any problems they normally had them fixed within a few minutes. As far as accuracy goes, The results were very dependable and repeatable. If you do sign up for the EGPs subscription tell Lonnie that Kale says hello.
I have a client who is wanting to use the VRS with Trimble gear, good to know that you had no issues using Trimble on that VRS. I think Trimble VRS NOW is a newcomer down there? Not really sure, since I hadn't heard of that network before. I remember the DOT was trying to setup a VRS (or was it just single base RTK?) for a while with Leica gear. I don't see any mention of that on their website.
There's a free statewide RTK network in Florida run by the DOT.
http://www.dot.state.fl.us/surveyingandmapping/gps.shtm
I haven't run Trimble gear on it, but other gear works well.
> I would like to get opinions on the two VRS networks that cover south Florida.
>
> Trimble VRS now and eGPS.
>
> How well does each work? Reliability? Accuracy?
>
> Has anyone used eGPS with Trimble gear? It should work fine, but are there any issues?
>
> My only experience with VRS is in PA using Keynet (Trimble), which works great. The accuracy issue would depend on the system operator, how tight they have their network setup, how accurate their reference receivers are with respect to the NSRS. If the reference station coordinates are not super accurate, then the results at the rover end are going to reflect that.
Thanks, I thought they had set one up, but for whatever reason i couldn't find it. It does appear it is a full fledged VRS, not just a single base rebroadcast (i.e. data from nearest base).
I wonder if they have updated from CORS96 to NAD83 (2011). Their FAQ says CORS96, but that may not have been updated. The four around me (Keynet, NYDOT, OHDOT, and NYDOT) have all been updated to 2011 as far as I know.
I wonder how that works, with a free service competing with a commercial service? Where I am PA does not have a free government run service, but OH, WV, and NY do. PennDOT uses the commercial VRS run by Keystone, although since they supply a number of the reference stations I think they get free or discounted access, maybe 1 rover license per station or something like that.
Since we are talking about different providers, there was a paper presented at Marakesh in 2011 about some tests Turkey performed of different VRS vendors prior to them buying a system.
It is actually a very good description of the system. I was at the presentation, unfortunately the presenter's english was very poor.
It's a Leica-based network, similar to vrs.
I thought they were updated 83-2011, but not positive.
Seems like public and commercial networks coexist in some states. I guess its hard for a commercial network to charge 300 hundred bucks a month in that case.
> Thanks, I thought they had set one up, but for whatever reason i couldn't find it. It does appear it is a full fledged VRS, not just a single base rebroadcast (i.e. data from nearest base).
>
> I wonder if they have updated from CORS96 to NAD83 (2011). Their FAQ says CORS96, but that may not have been updated. The four around me (Keynet, NYDOT, OHDOT, and NYDOT) have all been updated to 2011 as far as I know.
>
> I wonder how that works, with a free service competing with a commercial service? Where I am PA does not have a free government run service, but OH, WV, and NY do. PennDOT uses the commercial VRS run by Keystone, although since they supply a number of the reference stations I think they get free or discounted access, maybe 1 rover license per station or something like that.
We use the FDOT network and it's OK. No Glonass as of yet and vertical isn't all that good from what we've seen, but HZ is great. Trying to get the company to go with eGPS....
Do you think the fuzzy vertical is due to lack of glonass or ??
> We use the FDOT network and it's OK. No Glonass as of yet and vertical isn't all that good from what we've seen, but HZ is great. Trying to get the company to go with eGPS....
When I was working in Florida, we had a subscription to the Trimble VRS Now network and had no problems with it at all. There is another private network that covers the state run by the survey supplier Lengemann of Florida. A company I used to work for down there had purchased 2 of their base stations when Lengemann was getting the network up and running. They are a Topcon dealer, so it's a Topcon network, but I used Trimble equipment on it with no issues. I believe it was a good bit cheaper than the Trimble network.
This is just what I remember, it's been almost 2 years.
-Adam
An Update
We tried both networks. The eGPS network offers a daily rate. Tommy (not sure his last name) provides tech support and has been very helpful. BUT....there are apparently areas in Florida where they do not have their own stations, so they supplement with FL DOT stations, which are GPS only. The field guy who was using it said that sometimes it would have high precisions (meaning numerically high, in the several centimeter range) and would be difficult to initialize.
On the other hand, the Trimble VRS NOW network worked flawlessly everywhere. Inits almost always took less than 5 seconds, and the precisions were under 5 mm consistently. I know that doesn't mean that the points are always that accurate, but we used the same equipment (R8 GNSS and TSC2 with survey controller 12.49 with both networks.
I don't mean to disparage the eGPS network, as it did work well when both GPS and Glonass were available, but there are areas where it only does GPS due to the reference station being GPS only.
Another observation: the Trimble network is much easier to subscribe to, just sign up on the web and give a credit card. they do not have a daily rate (they really should), but they did give some free time for demo. They have either year subscription or 100 hours over a year. eGPS sends a form to be filled out, so there is some back-and-forth. But, they do offer a daily rate with a monthly cap as well as a year subscription.
