Activity Feed › Discussion Forums › GNSS & Geodesy › HORRIBLE OPUS results
Great thank you, I have stopped by there before, but I haven’t spent much time there – I will now.
A bit more information…I had “blindly” been using teqc to convert raw files to rinex to submit to OPUS. I hadn’t really paid attention to what was in there other than to make sure there were no comment lines in the data and that it said either G (GPS) or M (MIXED) at the top. Usually files processed just fine in OPUS but it was typically older receivers (4700/5700/R8). I was not using any switches like +C2 or +all to get more observation types in. After reading some online info about teqc I see that by default it only includes a limited number of observation types.
So, just now I downloaded the same file using the onboard convert to rinex function on the R10. It has 17 types of observables…
C1 L1 S1 P1 C2 L2 S2 P2 C5 L5 S5 C7 L7 S7 C8 L8 S8
After I changed an L2 parameter in the receiver, it now produces 20 types of observables…
L1 L2 L5 L6 L7 L8 C1 P1 C2 P2 C5 C6 C7 C8 S1 S2 S5 S6 S7 S8
I had GPS, Glonass, and Galileo turned on, I did not have Beidou turned on. I have a new Alloy receiver, I am going to turn everything on and see what it collects.
There is a short blurb on the OPUS page that tells what is required in a file:
I think it could be a bit more specific. As I said, I am not a frequent user of OPUS, mainly use it as a check on my own processing and as an additional check to include in reports.
I have Z12 and Zsurvey. I use opus a lot.
Maybe it??s just a more favorable situation in the northeast. I routinely collect 90 min. And I do have to edit the date. I repeat occupations as opportunity presents itself. And I get 2-3 mm the same results. I often resubmit data weeks later for better orbits, and that returns 1-2 mm.
The output shows 8-10 cors, which are 20-120 km distant.
I have had the occasional (rare) rejected data set. But, resubmit a week later and more often than not, opus returns no issues.
Can??t fault the 1999 firmware. Download, convert to rinex, and I do have a simple datefix.exe for rinex 2.11 files. It doesn??t get easier. But I realize there might be faster.
Final Update…I resent the three files to OPUS (after using the +C2 switch in teqc), all came back with good results. The comparison to RTX was excellent.
As I mentioned, there is a RTN station (Nevada GPS Network, run by Utah) nearby in Gerlach (about 13 km). I processed that data against my base station, and the misclosure was 0.132 m horizontally and +0.010 m in height. The fact that the height agreed was reassuring. It appears that the RTN coordinate is “NAD83/94 (HARN)”, but I am surprised it is that far off.
John,
I just ran a crude test with HTDP using a rough latitude/longitude (fake ellipsoid height) for Gerlach to see what the modeled displacement was from 1994 to 2010.00. Here are the results. The 0.132 meter horizontal difference seems somewhat reasonable:
UPDATED POSITIONS IN NAD_83(2011/CORS96/2007) FROM 1-01-1994 TO 1-01-2010 (month-day-year) FROM 1994.000 TO 2010.000 (decimal years) OLD COORDINATE NEW COORDINATE VELOCITY DISPLACEMENT Gerlach LATITUDE 40 39 6.00000 N 40 39 6.00274 N 5.28 mm/yr 0.084 m north LONGITUDE 119 21 26.00000 W 119 21 26.00224 W -3.29 mm/yr -0.053 m east ELLIP. HT. 1000.000 999.978 -1.38 mm/yr -0.022 m up X -2376080.010 -2376080.021 -0.67 mm/yr -0.011 m Y -4224233.914 -4224233.826 5.52 mm/yr 0.088 m Z 4133803.563 4133803.613 3.11 mm/yr 0.050 m
They say NAD83/94 but don’t give an epoch date, that is why I didn’t try something like that. I guess you use 1994.0?
Yes, I used 1994.0. The California HPGN/HARN is NAD83 epoch 1991.35. Not sure about the Nevada HARN? I was just curious what the general magnitude would be from circa 1994 to 2010.00.
No epoch date cited in this paper by Dave Doyle either:
There is a CBN (PID LS0540) station in Gerlach. I wanted to occupy it but I had a flat tire and a plane to catch…
It has a published NAD83(94) order B position on the data sheet. Inversing them gives 0.156 m
Have you sent the uploaded data file from the R10 to OPUS with no editing? I haven’t seen much difference at all between RTX and OPUS by using TBC to send the file off, I’ve never converted them to RINEX before sending, I’ve only used the TBC processing service since I got it. Normally RTX and OPUS will be within a few mms. horizontally, more variation vertically.
I would say the difference all depends on the CORS being used in OPUS. Some CORS are better than others…
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