I have an OPUS Projects session that doesn't want to accept one of my occupations. The OPUS numbers look good, but Projects won't include it. I've tried processing it several times, but I get the same result. What am I overlooking?
I think I figured it out -- somehow I unchecked the "include" box for that occupation, and left it unchecked 3 times without seeing it. I'm awaiting the results, but that should take care of it.
Operator error. Nothing to see here, move along please.
> I think I figured it out -- somehow I unchecked the "include" box for that occupation, and left it unchecked 3 times without seeing it. I'm awaiting the results, but that should take care of it.
>
> Operator error. Nothing to see here, move along please.
You know, that was the very first thing that popped into my mind (aside from the possibility that you had some L2 clogging the receiver that needed to be cleaned out with a smart rap on a hard surface), but I thought "Naw, this is Jim Frame on this project. It would be insulting even to ask. Too unlikely."
It looks like you don't have common time on 1031 and S16A. Your A Session used 1031 and it should not have been included in the B session. Sometimes projects does funny things with the sessions. Did you move from 1031 to S16A with the same receiver?
I also notice that you have an antenna height on p217 of 0.008. Is there a reason for this? This looks like an interesting project. I hope that in the near future NGS allows us to share our OPUS Projects positions.
🙂 😀
When GPS Projects get big, you need this to help with the adjustment. :beer: :beer:
> It looks like you don't have common time on 1031 and S16A. Your A Session used 1031 and it should not have been included in the B session. Sometimes projects does funny things with the sessions. Did you move from 1031 to S16A with the same receiver?
>
> I also notice that you have an antenna height on p217 of 0.008. Is there a reason for this?
On this project I had 5 receivers running, 2 of them unattended all day and the other 3 roving for 1-hour sessions. The schedule allowed the S16A and 1031 receivers to stay put for back-to-back sessions, so I was able to get 2+ hours on those and thus submit to OPUS. Also shown are P271 and UCD1 -- both CGPS stations. P271 is a PBO station and also an NGS CORS, which accounts for the 0.008 m antenna height (the distance from the ARP to the GRM). It's right at the edge of my project and susceptible to the land subsidence that I'm monitoring, so I'm treating it as just another rover.
I have one more session to run today to wrap up the field work, which will give me one more OPUS session at DAVE, but these are all the OPUS occupations in the project so far:
The whole network looks like this:
I'm using OPUS Projects to bring heights in from known stable CORS, since everything in the vicinity of the project is suspect vertically.
Interesting that you have a station S16A. There was a station of the same designation (PID DH6905)off Cordelia Road at Suisun Creek. It was set in 2001 as part of the Delta-Suisun Marsh network, but was destroyed a few years later by the replacement of the bridge.
Cool project, thanks for posting.
How do you determine a "known stable" CORS. I had always assumed all CORS stations are spot on...
I am sure Jim is looking at the time series plots of CORS/CGPS stations. Station UCD1 in the SW corner of his network is known to have a significant seasonal "up and down" cycle of several centimeters, from what I recall. Here is the detrended time series plot for his station P271:
ftp://www.ngs.noaa.gov/cors/Plots/Longterm/p271_08.long.png
Here is the daily time series plot for P271 from the station owner, UNAVCO/PBO:
Wow some serious variation. Thanks for the info.
> Interesting that you have a station S16A. There was a station of the same designation (PID DH6905)off Cordelia Road at Suisun Creek.
Complete coincidence. A station named SM No. 16 was set in 1991 on my project, but was destroyed by farming operations, so I set a replacement nearby. By dint of old habit, I use a 4-character naming convention, so I called the new one S16A.
My project is looking at subsidence due to groundwater pumping and P271 is in the potential drawdown zone, so I'd be excluding its CORS height even if it were stable in the past. And the last time I checked, NGS won't change the published height of a CORS until the change exceeds 2 cm, so it's better to treat it as an unconstrained station.
Do any of your CORS have Orthometric Heights on the ARP? Several of ours do. If you use them as CORS in an OPUS Project, you can't fix the NAVD88 Height and the Geoid Model will be off by a few mm. I sometimes exclude them from my initial processing and download the data and treat them like a point that I occupied. Then when I do the adjustment, I use the far away CORS and horizontal only and the close in ones with orthometric heights on the, I constrain in all 3 dimensions. It is a little more work but it gets me the results that I need. Most of our CORS are also stable.
