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OPUS vs. RTX

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paul-in-pa
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Even if it is using CORS differently? one would want to know what CORS. The ephemerides used must be the best possible for all 3 GNSS galaxies.

Paul in PA


 
Posted : January 2, 2019 12:40 pm
stlsurveyor
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Okay so I uploaded the same Rinex file to Javad DPOS. Here are the results:

  DPOS REPORT
                              JAVAD POST-PROCESSING SERVICE
                              =============================


      USER:                                         DATE: 02.01.2019 
      FILE: 1                                       TIME: 21:55:49.763 GPS time


  SOFTWARE: DPOS(12/26/2018 6:34:52 PM)            START: 2018/12/17 04:47:29.000 PM       
 EPHEMERIS: brdc                                    STOP: 2018/12/17 08:02:16.000 PM       
  OBS USED: 11148 / 11164                      TIME SPAN: 195 min                          
  ANT NAME: TRMR10          NONE         Geometry factor: 3.2                              
ANT HEIGHT: Vertical(ARP) - 5.901 survey feet  FIXED AMB: Yes
ANT DELTA N/E/H: 0.000/0.000/0.000           OVERALL RMS: 0.015 survey feet


 REF FRAME: NAD83(2011)(EPOCH:2010.0000)               IGS08 (EPOCH:2018.9603)

          X:      -133455.517(sft)   0.008(sft)           -133458.429(sft)   0.008(sft)
          Y:    -16061569.967(sft)   0.009(sft)         -16061565.447(sft)   0.009(sft)
          Z:     13367832.697(sft)   0.009(sft)          13367832.371(sft)   0.009(sft)

        LAT: N 39 57 30.70815        0.008(sft)      N 39 57 30.73420        0.008(sft)
      E LON:E 269 31 26.18603        0.009(sft)     E 269 31 26.14816        0.009(sft)
      W LON: W 90 28 33.81397        0.009(sft)      W 90 28 33.85184        0.009(sft)
     EL HGT:          339.054(sft)   0.009(sft)               335.399(sft)   0.009(sft)
  ORTHO HGT:          447.096(sft)   0.009(sft) [NAVD88 (Computed using GEOID12B)]

                        UTM COORDINATES    STATE PLANE COORDINATES
                          UTM (Zone 15)     SPC (NAD83(2011) /1202 Illinois West)
Northing (Y) [survey feet]  14521641.317           1198912.698      
Easting (X)  [survey feet]   560216.538            2209855.537      
Convergence  [degrees]      1.62158159            -0.19870335      
Point Scale                 1.00017220             0.99994978      
Combined Factor             1.00015599             0.99993356      

US NATIONAL GRID DESIGNATOR: NONE


                              BASE STATIONS USED
PID    DESIGNATION                  LATITUDE       LONGITUDE     DISTANCE(sft)
NONE   ILSA(CORS)                 N 39 46 43.060 W 89 36 37.0518 251703.9
NONE   MOBG(CORS)                 N 39 20 51.793 W 91 12 28.3111 303260.0
NONE   MOCN(CORS)                 N 40 08 36.688 W 91 32 37.6673 306421.7
NONE   MOEB(CORS)                 N 39 10 44.087 W 90 47 15.5391 297260.0
NONE   MOHL(CORS)                 N 39 41 43.571 W 91 24 05.0049 277006.3

                              RESIDUALS OF POSITION
VECTOR              dX,sft      dY,sft      dZ,sft      dN,sft      dE,sft       dU,sft
ILSA - 1          -0.015   0.018   0.011   0.020  -0.015  -0.007
MOBG - 1           0.010  -0.003  -0.011  -0.010   0.010  -0.004
MOCN - 1          -0.023   0.023   0.012   0.024  -0.023  -0.010
MOEB - 1          -0.022  -0.023   0.013  -0.005  -0.022   0.026
MOHL - 1           0.037  -0.012  -0.019  -0.022   0.037  -0.003
Solution name:                MOHL - 1 / Solution 1
Processed at:                 1/2/2019 9:55:16 PM
Begin time:                   17/12/2018 16:47:29.000
End time:                     17/12/2018 20:02:16.000
Time span, min:               195
Rec interval, sec:            30.000
Ephemeris:                    Broadcast
Cut off ?øngle,?ø:              12
Processing mode:              Auto
Frequency:                    L1 + L2
Used satellites:              GPS(18)/GLONASS(12)
Solution type:                Fixed
Temperature, ?øC:              20
Pressure, hPa:                980
Humidity, %:                  50

Used observations:            L1, L2, P1, P2

N10,000, E7,000, Z100.00
PLS - IL, MO, AR, KS, MN, KY

 
Posted : January 2, 2019 12:59 pm
stlsurveyor
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DPOS
N 39 57 30.70815
W 90 28 33.81397

RTX
N 39 57 30.70887
W 90 28 33.81415

OPUS
N 39 57 30.70786
W 90 28 33.81431


N10,000, E7,000, Z100.00
PLS - IL, MO, AR, KS, MN, KY

 
Posted : January 2, 2019 1:02 pm
Norman_Oklahoma
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That has a lot in common with the OPUS report, except it reports in feet, which is nice.?ÿ


 
Posted : January 2, 2019 1:03 pm
stlsurveyor
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I agree - I hope Javad keeps the processing open to all from here on out. Its amazing how close they all are to each other

DPOS
N 39 57 30.70815?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ N 1198912.699
W 90 28 33.81397?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿE 2209855.537

RTX
N 39 57 30.70887?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ N?ÿ 1198912.772
W 90 28 33.81415?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ E 2209855.52

OPUS
N 39 57 30.70786?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿN 1198912.670
W 90 28 33.81431?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ E?ÿ 2209855.51


N10,000, E7,000, Z100.00
PLS - IL, MO, AR, KS, MN, KY

 
Posted : January 2, 2019 1:12 pm

bill93
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Posted by: Norman Oklahoma

That has a lot in common with the OPUS report, except it reports in feet, which is nice.?ÿ

CAN SELECT to report in feet.

Beware that little number following the DPOS coordinates.?ÿ It is apples and pomegranates to the little number OPUS reports.?ÿ OPUS gives pk-pk differences in the solutions from its chosen CORS.?ÿ DPOS gives something akin to a standard error for the variation throughout the session, but ignores any difference in the CORS solutions, which is tabulated separately as residuals in the extended report.


 
Posted : January 2, 2019 1:15 pm
john-hamilton
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40677.331*39.37/12=133455.543 (OPUS)

40677.327*39.37/12=133455.530 (RTX)

?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ N 0.013

4895576.300*39.37/12=16061569.911 (OPUS)

4895576.272*39.37/12=16061569.819 (RTX)

?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿ ?ÿE?ÿ ?ÿ0.092

?ÿ

NOTE: ECEF XYZ does not equal NEU!


 
Posted : January 2, 2019 1:17 pm
stlsurveyor
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Posted by: John Hamilton

NOTE: ECEF XYZ does not equal NEU!

Correct, I just grabbed that as a comparison since it was on both reports - defaulted to Lat/Long now


N10,000, E7,000, Z100.00
PLS - IL, MO, AR, KS, MN, KY

 
Posted : January 2, 2019 1:19 pm
john-hamilton
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I made a recent request of the RTX team to add UTM to the output, since it is easy to know exactly what zone a point is in by looking at the latitude (N/S) and longitude (6?ø zone widths).?ÿ

The reply was "However, at this time, enhancements for the free service are not a priority for us."

I would be willing to pay a nominal subscription fee for an enhanced RTX, with more output info and also the ability to upload multiple files automatically and have each returned as a separate output file. At least they got rid of the annoying catcha type thing you had to enter for each upload.?ÿ

?ÿ


 
Posted : January 2, 2019 1:24 pm
base9geodesy
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I find the uncertainty estimate of the Javad orthometric height interesting.?ÿ The report shows it to be identical to the ellipsoid height (.009 sft).?ÿ That would indicate that the uncertainty of the geoid height from GEOID12B is 0.000 sft which of course is not correct.?ÿ Since we can't access the GEOID12B model at this time I can't use to tool to see what NGS estimates the value is at the point observed, however I can feel pretty safe that it's likely in the range of .1 to .16 sft.?ÿ As I've mentioned before on this site, anyone using any post processing utility should look very carefully at the orthometric height uncertainty - they are all very much on the optimistic side.?ÿ Depending on where you are in the conterminous US GEOID12B's 2-sigma uncertainty published by NGS varies from .1 ft to .3 ft.


 
Posted : January 2, 2019 1:27 pm

stlsurveyor
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Posted by: base9geodesy

...... As I've mentioned before on this site, anyone using any post processing utility should look very carefully at the orthometric height uncertainty - they are all very much on the optimistic side.?ÿ Depending on where you are in the conterminous US GEOID12B's 2-sigma uncertainty published by NGS varies from .1 ft to .3 ft.

I would love someone here who is much smarter than me to direct me to some good articles / text on how to really understand what these reports are saying and know what to look for - and understand what matters. I really feel like I have let myself get dumb on VRS networks..


N10,000, E7,000, Z100.00
PLS - IL, MO, AR, KS, MN, KY

 
Posted : January 2, 2019 1:32 pm
bill93
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Since DPOS reports the variation throughout the session and ignores the differences between CORS reports (until the residuals section), the variation number is usually very small and not of much use in determining the uncertainty of the final answer. ?ÿ I would expect the Ortho variation number to be always identical to the El Ht variation?ÿ number.?ÿ Neither OPUS nor DPOS accesses the geoid uncertainty.


 
Posted : January 2, 2019 1:38 pm
loyal
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Posted by: Bill93

Since DPOS reports the variation throughout the session and ignores the differences between CORS reports (until the residuals section), the variation number is usually very small and not of much use in determining the uncertainty of the final answer. ?ÿ I would expect the Ortho variation number to be always identical to the El Ht variation?ÿ number.?ÿ Neither OPUS nor DPOS accesses the geoid uncertainty.

I dunno bout that Bill;

?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ LAT:?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 40 36 55.89760?ÿ?ÿ?ÿ?ÿ?ÿ 0.005(m)?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 40 36 55.91402?ÿ?ÿ?ÿ?ÿ?ÿ 0.005(m)
?ÿ?ÿ?ÿ?ÿ?ÿ E LON:?ÿ?ÿ?ÿ?ÿ?ÿ 248 32 38.49436?ÿ?ÿ?ÿ?ÿ?ÿ 0.003(m)?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 248 32 38.43992?ÿ?ÿ?ÿ?ÿ?ÿ 0.003(m)
?ÿ?ÿ?ÿ?ÿ?ÿ W LON:?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 111 27 21.50564?ÿ?ÿ?ÿ?ÿ?ÿ 0.003(m)?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 111 27 21.56008?ÿ?ÿ?ÿ?ÿ?ÿ 0.003(m)
?ÿ?ÿ?ÿ?ÿ EL HGT:?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ ?ÿ2112.740(m)?ÿ?ÿ 0.013(m)?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 2112.017(m)?ÿ?ÿ 0.013(m)
?ÿ ORTHO HGT:?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ 2128.252(m)?ÿ?ÿ 0.027(m) [NAVD88 (Computed using GEOID12B)]

Looks to me like OPUS has applied an "additional" uncertainty to the ORTHO HGT P-P

Loyal?ÿ


 
Posted : January 2, 2019 1:48 pm
lee-d
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Shawn thanks for the clear and concise explanation.


 
Posted : January 2, 2019 2:09 pm
shawn-billings
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Posted by: base9geodesy

I find the uncertainty estimate of the Javad orthometric height interesting.?ÿ The report shows it to be identical to the ellipsoid height (.009 sft).?ÿ That would indicate that the uncertainty of the geoid height from GEOID12B is 0.000 sft which of course is not correct.?ÿ Since we can't access the GEOID12B model at this time I can't use to tool to see what NGS estimates the value is at the point observed, however I can feel pretty safe that it's likely in the range of .1 to .16 sft.?ÿ As I've mentioned before on this site, anyone using any post processing utility should look very carefully at the orthometric height uncertainty - they are all very much on the optimistic side.?ÿ Depending on where you are in the conterminous US GEOID12B's 2-sigma uncertainty published by NGS varies from .1 ft to .3 ft.

Thank you, Dave. I'll pass that along!


 
Posted : January 2, 2019 2:10 pm

lee-d
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I have several days worth of photo control files that I REALLY wish I'd taken the time to process prior to going on holiday...

?ÿ


 
Posted : January 2, 2019 2:13 pm
bill93
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Posted by: Loyal

Looks to me like OPUS has applied an "additional" uncertainty to the ORTHO HGT P-P

Loyal

Oh, yes OPUS does add an additional uncertainty.?ÿ I just isn't from Geoid12B, or any geoid model's uncertainty that depends on your point's lat-lon.

We had a thread two years ago on this, where someone at NGS told us the formula and it checked with some of my example reports.?ÿ It uses some fixed generic geoid uncertainty that is pretty optimistic, and also screws up the formula for adding that to your El Ht uncertainty.

?ÿ


 
Posted : January 2, 2019 3:16 pm
loyal
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Posted by: Bill93
Posted by: Loyal

Looks to me like OPUS has applied an "additional" uncertainty to the ORTHO HGT P-P

Loyal

Oh, yes OPUS does add an additional uncertainty.?ÿ I just isn't from Geoid12B, or any geoid model's uncertainty that depends on your point's lat-lon.

We had a thread on this quite a while ago, where someone at NGS told us the formula and it checked with some of my example reports.?ÿ It uses some fixed generic geoid uncertainty that is pretty optimistic, and also screws up the formula for adding that to your El Ht uncertainty.

I agree with you Bill.

Inasmuch as my work rarely involves serious "elevations," and the fact that current (and historic) geoid models are kinda flakey?ÿhere in the Mountain West, I pretty much just look at the NAVD88 height as a "better than nothing" value. I should point out however, that in some areas, OPUS NAVD88 heights on several miles of (stable) Bench Marks can (and often do) return very good results, and sometimes even better dH between BMs than one might expect.

On a related note, I can't wait for the results of the ?ÿ2018 (or was it 2017)?ÿGeoid Slope project in Colorado to be published. I suspect that it will be an eye opener!?ÿ?ÿ

Loyal


 
Posted : January 2, 2019 3:32 pm
base9geodesy
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As I noted in a recent post the NGS GEOID12B utility does provide their 2-sigma (95% confidence) for any geoid height.?ÿ Regrettably for some unknown reason they don't show that value on the standard control datasheet and the NGS OPUS team also does not use it but rather some other uncertainty (as Bill93 noted) which has nothing to do with the GEOID12B model.?ÿ I did raise this issue with the Chief Geodesist back in September who shuffled it off to someone else who indicated they would work on it - nothing so far.?ÿ So as I said be very, very cautious accepting the orthometric height uncertainty until these issues are resolved.?ÿ


 
Posted : January 2, 2019 3:57 pm
john-hamilton
(@john-hamilton)
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See the reply by Joe Evjen (joegeodesist) in this post a few years ago for an explanation of how the Ortho height uncertainty is computed...

?ÿ

https://surveyorconnect.com/community/gnss-geodesy/opus-height-uncertainty/#post-406336

?ÿ


 
Posted : January 2, 2019 4:48 pm

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