In the past month I have had issues with two different VRS (WV=Trimble, MI=Leica) where in one certain area in each, close to a physical CORS, I could not get a good solution. Everywhere else it works fine. It happened to me in one area, then my employee was in the same area a week later and same thing. This week he is in a totally different network, different state, and once again close to a CORS but can't initialize.
I have verified that in each case the CORS is shown as healthy. I am thinking that there is a bad coordinate for the CORS and they haven't detected that?
Anyone else seen this?
Why not select a different CORS station, one that is farther away?
Bad cell service?
I am thinking that there is a bad coordinate for the CORS and they haven't detected that?
Most networks recently switched over to MY3. Have you confirmed that the broadcast coordinates are the same as the published. That being said, I'm not really sure why a bad CORS coordinate would cause a failure to initialize at close range but not as the distance increased.
How close is close anyway? I'm not sure how VRS systems work, but Leica Spyder networks can automatically switch form a MAX network to single nearest correction automatically when you are within a certain distance of the nearest CORS. This feature in enabled at on the administrator's side. I think SmartNet is set to 5km while ODOT's system does not have it activated at all.
@landbutcher464mhz Network solution, not single base.
@john-putnam They both work fine in other areas. The WV projects covers about 2/3 of the state, so multiple CORS are being used. I was actually impressed with how well the WV network worked. I have said for 40 years that WV is the toughest state to survey in, conventional or GNSS. It actually works better in my opinion than a nearby commercial VRS network. Faster inits, better rms, better dups. Except for that one area.
That is why I suspect a single CORS. It is possible that they didn't update all of the coordinates. My tech did contact one of the networks, they said go single base, but I am leery of that since I suspect a bad coordinate. Of course I can download data from that CORS and produce my own coordinate as a check.
Maybe I misunderstood you. Can you get a fix with the suspect CORS as your distance from that particular CORS increases or is the failure to initialize anytime that CORS is the master in the network solution. If you are still in the area, it would be interesting to collect some RTK data via a single base correction to see if that works. If it does, then that would suggest somethings up with the networks. That really seems unlikely since the RTK network software is supposed to monitor that kind of thing.
Sounds like you might want to check your communications in those areas. You've been doing this stuff long enough that you can check the CORS position, but latency in your correction info might be tougher to track and will affect your solution.