RTN Head-Scratcher

[Jim Frame]

I often use a nearby CRTN station, UCD1. Recently something happened -- still don't know what -- that resulted in a configuration problem such that the base position message wasn't being transmitted. After a lot of back-and-forth with both CRTN folks and BARD folks (BARD owns the base receiver and directs the stream to CRTN), the base position message seems to be back, but my Triumph-LS isn't getting the data it needs.

Here's a screenshot of the RTK engines when connected to UCD1:

And a screenshot of the WiFi screen:

When I change the mountpoint to another CRTN station (P268), the RTK screen looks normal:

WiFi when connected to P268:

I still need to look at the stream data (using SNIP) to see if I can find the difference, but I'm wondering if anyone can tell from these screenshots what might not be getting through.

Thanks!

P.S. Coincidentally, while I was trying to diagnose the problem BARD decided to upgrade the receiver and antenna at UCD1. I don't think that has anything to do with the problem, but it does complicate matters a little.

 

[Adam]

Everything looks good to me Jim. Did you reselect the mountpoint from setup after the change? Maybe worth a try.

 

[Jim Frame]

I looked at the caster streams with SNIP and saw that the 1007 message from UCD1 is blank ("antdesc= antsetup=0"), while the P268 1007 message is populated ("antdesc= TRM59800.80 SCIT antsetup=0"). Would lack of an antenna descriptor cause the RTK engine to reject the stream and show no data?

 

[Jim Frame]

Another difference between the UCD1 stream and those from other CRTN stations: in the 1004 messages, in the L1 Code column, UCD1 shows "L1P," while all the other stations I checked (1 BARD and 3 UNAVCO) show "L1C." I didn't find any detail on the meaning of those entries in the SNIP documentation, but the fact that there's a difference would seem to be significant.

 

[Michael Stazhkov]

I often use a nearby CRTN station, UCD1. Recently something happened -- still don't know what -- that resulted in a configuration problem such that the base position message wasn't being transmitted. After a lot of back-and-forth with both CRTN folks and BARD folks (BARD owns the base receiver and directs the stream to CRTN), the base position message seems to be back, but my Triumph-LS isn't getting the data it needs.

Jim, could you create a new empty project, record a standalone point with raw GNSS data (allow standalone position in action profile) and send to support the project. We will check corrections stream in the raw GNSS file.

 

[Jim Frame]

Sent. Thanks!

 

[Michael Stazhkov]

Sent. Thanks!

Jim, There are no corrections from server in the file. There are only 3 text messages from server like this:
"Server: Geodetics CommLinkProxy Version 3.5 EV..Date: 05/Nov/2019:15:45:40 UTC.."
Did you set sending of NMEA GGA message to the server?

 

[Jim Frame]

Did you set sending of NMEA GGA message to the server?

If you mean the GGA box checked below, I normally don't have that checked, but I checked it this morning and shot another couple of points. The first was standalone using UCD1 as the mountpoint, the second is RTK fixed using P268 as the mountpoint. The project has been sent to support.

 

[Michael Stazhkov]

If you mean the GGA box checked below, I normally don't have that checked, but I checked it this morning and shot another couple of points. The first was standalone using UCD1 as the mountpoint, the second is RTK fixed using P268 as the mountpoint. The project has been sent to support.

Yes, checking of NMEA GGA checkbox helped. Now the file contains corrections from reference station.
But even post-processing engine has problem with fixing on the data. They are trying to understand the problem. May be tomorrow we will find a reason. Now they said some problem with L1 signal.

 

[Michael Stazhkov]

I often use a nearby CRTN station, UCD1. Recently something happened -- still don't know what -- that resulted in a configuration problem such that the base position message wasn't being transmitted. After a lot of back-and-forth with both CRTN folks and BARD folks (BARD owns the base receiver and directs the stream to CRTN), the base position message seems to be back, but my Triumph-LS isn't getting the data it needs.

1) To get corrections from the station it needs position of receiver (NMEA GGA checkbox).
2) It seems something wrong from the provider side. From our RTK and post-processing teams experience such bad measurements (like we see in the provided file) could be because of wrong reference station position used to create the correction stream.

We also have checked the rover receiver measurements (Triumph-LS) using nearby CORS stations and the measurements is good.