1. OPUS : Online Positioning User Service http://www.ngs.noaa.gov/OPUS/ ngs.opus@noaa.gov

2. WHAT IS OPUS? On-line Positioning User Service Fast & easy access to the NSRS (National Spatial Reference System) for GPS users

3. Areas Covered by OPUS

4. How Does OPUS Work? Data submitted through NGS web page Processed automatically with NGS computers & software Position with respect to 3 suitable CORS (or IGS sites if 1) no NAD 83 positions are available and 2) the host country has an agreement with NGS. In these international cases, ITRF coordinates only are returned, and there are no state plane or US grid coordinates Solution via email (usually in minutes)

5. OPUS Guidelines Dual-frequency data (L1/L2) Minimum 2 hrs of data (maximum 48— only cross midnight once) No kinematic or L1 only (OPUS-GIS Proposed) No Glonass. Galileo will be discussed as the constellation becomes available Accurate height requires:  correct antenna type  correct antenna height

6. How Does OPUS Compute Position? 3 single baselines computed 3 positions averaged — simple mean (equal weights) Differences between positions include any errors in CORS coordinates

7. Time-series plots, 60-day and long-term web page 60-day time series Long-term time series The time series plots provide a means of evaluating the small changes in position of a CORS.

8. How Does OPUS Pick Base Stations? 1.Estimate position for remote station 2.Compute distance to every available CORS 3.Sort CORS by increasing distance 4.Select the 5 closest CORS 5.Look at 1 st 3 CORS with TEQC program. Criteria: ● data cover time span for remote station ● > 80% of data available ● low multipath ● if not, replace with 4 th CORS (then 5 th ) 6. Start single baseline solutions using 1 st 3 CORS ● check solution quality ● if bad solution, replace CORS with 4 th (then 5 th )

9. CORS Selection (example = CORV solved from CHZZ, NEWP, P376)

10. Quick Link to OPUS from NGS Home Page www.ngs.noaa.gov

11. Using the OPUS Web Page

12. Allowable Data Formats Compressed archive of multiple files. Archive must contain RINEX “site123h.04o” or Hatanaka “site123h.04d” Compressed individual files.“Site123h.zip”must contain “site123h.06o” or “site123h.06d” Manufacturer’s native / raw (binary) —uncompressed--as long as UNAVCO’s teqc program can process it RINEX Receiver Independent Exchange-- uncompressed

13. Select or exclude base stations including Cooperative CORS Select state plane coordinate zone Extended Output Set user profile Associate antenna type, antenna height, SPC code, selected base stations and extended option choices with your email address

14. FILE: corv0590.05o 000416827 1008 NOTE: Antenna offsets supplied by the user were zero. Coordinates 1008 returned will be for the antenna reference point (ARP). 1008 NGS OPUS SOLUTION REPORT ======================== USER: jeff.olsen@noaa.gov DATE: January 13, 2006 RINEX FILE: corv059f.05o TIME: 19:08:14 UTC SOFTWARE: page5 0601.10 master3.pl START: 2005/02/28 05:00:00 EPHEMERIS: igs13121.eph [precise] STOP: 2005/02/28 06:59:30 NAV FILE: brdc0590.05n OBS USED: 4228 / 4314 : 98% ANT NAME: ASH700936B_M NONE # FIXED AMB: 25 / 29 : 86% ARP HEIGHT: 0.0 OVERALL RMS: 0.013(m) REF FRAME: NAD_83(CORS96)(EPOCH:2002.0000) ITRF00 (EPOCH:2005.1596) X: -2498423.165(m) 0.018(m) -2498423.872(m) 0.018(m) Y: -3802822.048(m) 0.021(m) -3802820.836(m) 0.021(m) Z: 4454737.695(m) 0.024(m) 4454737.792(m) 0.024(m) LAT: 44 35 7.91054 0.002(m) 44 35 7.92698 0.002(m) E LON: 236 41 43.48129 0.014(m) 236 41 43.42434 0.014(m) W LON: 123 18 16.51871 0.014(m) 123 18 16.57566 0.014(m) EL HGT: 107.485(m) 0.034(m) 107.108(m) 0.034(m) ORTHO HGT: 130.010(m) 0.043(m) [Geoid03 NAVD88] UTM COORDINATES STATE PLANE COORDINATES UTM (Zone 10) SPC (3601 OR N) Northing (Y) [meters] 4936954.907 105971.557 Easting (X) [meters] 475821.322 2277335.385 Convergence [degrees] -0.21381402 -1.98897497 Point Scale 0.99960719 0.99994603 Combined Factor 0.99959034 0.99992918 US NATIONAL GRID DESIGNATOR: 10TDQ7582136955(NAD 83) BASE STATIONS USED PID DESIGNATION LATITUDE LONGITUDE DISTANCE(m) AH2489 NEWP NEWPORT CORS ARP N443506.072 W1240342.736 60138.7 AJ6959 CHZZ CAPE MEARS CORS ARP N452911.437 W1235841.187 113322.4 DH4503 P376 EOLARESVR_OR2004 CORS ARP N445628.313 W1230608.100 42648.2 NEAREST NGS PUBLISHED CONTROL POINT AH2486 CORVALLIS CORS ARP N443507.910 W1231816.519 0.0 OPUS Output Standard

15. USER: jeff.olsen@noaa.gov DATE: January 13, 2006 RINEX FILE: corv059f.05o TIME: 19:08:14 UTC SOFTWARE: page5 0601.10 master3.pl START: 2005/02/28 05:00:00 EPHEMERIS: igs13121.eph [precise] STOP: 2005/02/28 06:59:30 NAV FILE: brdc0590.05n OBS USED: 4228 / 4314 : 98% ANT NAME: ASH700936B_M NONE # FIXED AMB: 25 / 29 : 86% ARP HEIGHT: 0.0 OVERALL RMS: 0.013(m) Reading OPUS Output The version of PAGES software used for processing The antenna type you selected and height of antenna reference point height you entered. Confirm that these are correct. The ephemeris used (OPUS will use the best available): “igs” final post-fit orbit--better than 1 cm (10-14 days wait) “igr” rapid post-fit orbit--better than 2 cm (17 hours wait) “igu” ultra-rapid predicted orbit--better than 20 cm (available immediately) Navigation file used Your email address & observation file. Solution run date & time

16. USER: jeff.olsen@noaa.gov DATE: January 13, 2006 RINEX FILE: corv059f.05o TIME: 19:08:14 UTC SOFTWARE: page5 0601.10 master3.pl START: 2005/02/28 05:00:00 EPHEMERIS: igs13121.eph [precise] STOP: 2005/02/28 06:59:30 NAV FILE: brdc0590.05n OBS USED: 4228 / 4314 : 98% ANT NAME: ASH700936B_M NONE # FIXED AMB: 25 / 29 : 86% ARP HEIGHT: 0.0 OVERALL RMS: 0.013(m) Start & end dates & times of your file Ratio and % of observations used in solution Ratio and % of fixed/total ambiguities Overall RMS of the solution Reading OPUS Output con’t.

17. Guidelines for Good Solution  Make sure antenna type and height are correct  Review statistics: at least 90% of observations should be used OBS USED: 4228 / 4314 : 98% at least 50% of the ambiguities should be fixed # FIXED AMB: 25 / 29 : 86% overall RMS should seldom exceed 0.030 m OVERALL RMS: 0.013(m)  In case of bad statistics, try choosing different CORS and re-submit.

18. REF FRAME: NAD_83(CORS96)(EPOCH:2002.0000) ITRF00 (EPOCH:2005.1596) X: -2498423.165(m) 0.018(m) -2498423.872(m) 0.018(m) Y: -3802822.048(m) 0.021(m) -3802820.836(m) 0.021(m) Z: 4454737.695(m) 0.024(m) 4454737.792(m) 0.024(m) LAT: 44 35 7.91054 0.002(m) 44 35 7.92698 0.002(m) E LON: 236 41 43.48129 0.014(m) 236 41 43.42434 0.014(m) W LON: 123 18 16.51871 0.014(m) 123 18 16.57566 0.014(m) EL HGT: 107.485(m) 0.034(m) 107.108(m) 0.034(m) ORTHO HGT: 130.010(m) 0.043(m) Reference frames. Epochs Position, xyz Peak-peak errors, xyz (range, max-min) Peak-peak errors may vary between NAD83 & ITRF Orthometric ht. is based on current geoid model Reading OPUS Output con’t. Solution/Coordinates [Geoid03 NAVD88] Position, lat / long / eh / oh Peak-peak for lat/long etc

19. How Does OPUS Compute Errors? EW S N 1 σ standard deviation peak-to-peak error more conservative ~ 2 σ peak-to-peak distances

20. UTM COORDINATES STATE PLANE COORDINATES UTM (Zone 10) SPC (3601 OR N) Northing (Y) [meters] 4936954.907 105971.557 Easting (X) [meters] 475821.322 2277335.385 Convergence [degrees] -0.21381402 -1.98897497 Point Scale 0.99960719 0.99994603 Combined Factor 0.99959034 0.99992918 US NATIONAL GRID DESIGNATOR: 10TDQ7582136955(NAD 83) Universal Transverse Mercator (UTM) coordinates State Plane coordinates (if requested) US National Grid OPUS Output con’t. Grid Coordinates

21. BASE STATIONS USED PID DESIGNATION LATITUDE LONGITUDE DISTANCE(m) AH2489 NEWP NEWPORT CORS ARP N443506.072 W1240342.736 60138.7 AJ6959 CHZZ CAPE MEARS CORS ARP N452911.437 W1235841.187 113322.4 DH4503 P376 EOLARESVR_OR2004 CORS ARP N445628.313 W1230608.100 42648.2 NEAREST NGS PUBLISHED CONTROL POINT AH2486 CORVALLIS CORS ARP N443507.910 W1231816.519 0.0 This position and the above vector components were computed without any knowledge by the National Geodetic Survey regarding the equipment or field operating procedures used. READING OPUS OUTPUT (control) Disclaimer Base Stations--NAD83 position--distance away The closest published station in the NGS data base In case you didn’t know it was there

22. How Can I Improve My Results? Consider observing a longer session Data sets of at least four hours have been shown to produce more reliable results Avoid conditions that perturb the GPS signal— unsettled weather, solar flares, multipath (nearby reflective surfaces)

23. Distribution of Horizontal Offset from Accepted Values 0.8 cm N-S RMS 1.4 cm E-W RMS > 200 CORS 2 hours of data

24. Distribution of Vertical Offset from Accepted Values 1.9 cm RMS All mean offsets < 1 mm > 200 CORS 2 hours of data

25. Error Messages and Warnings Resolution of the example messages below depends on circumstances. If there is a problem with software or hardware on the NGS side, sometimes just re-submitting the data file later is successful. If there is a problem with your data file, reobservation may be necessary. The time span of the submitted dataset is too short. OPUS needs a minimum of two hours worth of data to begin processing. The dataset submitted to OPUS does not meet the RINEX standard. Please re-submit the data in RINEX 2.0 or 2.1 standard. Aborting... The dataset submitted to OPUS contained too many data gaps or a large number of sampling interval changes. Aborting... WARNING! No antenna type selected. An antenna pattern will not be applied. The observations to slip ratio is too low. There were an unusually high number of cycle slips in the dataset. Aborting... ERROR! Opus terminated abnormally in one of the processing modules.

26. How do I get help? Study the Guidelines under “Using OPUS” Submit specific questions, comments or suggestions using “Contact OPUS” link Study the answers under “FAQs”

27. How to find the cause of 75% of OPUS failures

29. Download TEQC from UNAVCO.org

30. Error example – blank line at the end of the file. Note: you will have to use the Command Prompt (to bring up: hit Start-Programs-Accessories)

31. RINEX file to be edited. You can use Notepad, Wordpad, or another text editor (we try to use VI – a UNIX based utility)

32. Recent Solutions

33. OPUS Extended Output

34. BASE STATION INFORMATION STATION NAME: newp a 10 (Newport; Newport, Oregon USA) ANTENNA: ASH700936B_M S/N=CR16197 XYZ -2548454.0306 -3769449.6516 4454636.5526 MON @ 1997.0000 (M) XYZ -0.0067 0.0016 -0.0042 VEL (M/YR) NEU -0.0000 -0.0000 1.4240 MON TO ARP (M) NEU -0.0000 0.0000 0.1089 ARP TO L1 PHASE CENTER (M) NEU -0.0000 0.0000 0.1274 ARP TO L2 PHASE CENTER (M) XYZ -0.0547 0.0131 -0.0343 VEL TIMES 8.1597 YRS XYZ -0.5680 -0.8402 0.9996 MON TO ARP XYZ -0.0434 -0.0643 0.0764 ARP TO L1 PHASE CENTER XYZ -2548454.6967 -3769450.5430 4454637.5944 L1 PHS CEN @ 2005.1596 XYZ 0.0000 0.0000 0.0000 + XYZ ADJUSTMENTS XYZ -2548454.6967 -3769450.5430 4454637.5944 NEW L1 PHS CEN @ 2005.1596 XYZ -2548454.6533 -3769450.4787 4454637.5180 NEW ARP @ 2005.1596 XYZ -2548454.0852 -3769449.6385 4454636.5184 NEW MON @ 2005.1596 LLH 44 35 6.08851 235 56 17.20688 21.9484 NEW L1 PHS CEN @ 2005.1596 LLH 44 35 6.08851 235 56 17.20688 21.8395 NEW ARP @ 2005.1596 LLH 44 35 6.08851 235 56 17.20688 20.4155 NEW MON @ 2005.1596 OPUS Extended Output: Base Station Information Each CORS has a section like the one above, with ITRF xyz coordinates computed using HTDP velocities for the epoch of the observations (mid-point of the session). Note the above CORS has a monument separate from the ARP (positions coincide but ellipsoid heights are different). Base station and antenna used Monument starting ITRF coordinates. NEU offsets ITRF XYZ at mid-pt of session ITRF lat long EH at mid-pt of session XYZ offsets and position Position offsets at mid-pt of session Velocity in XYZ. These values are usually 0.000 for CORS (as they are here). The differences between initial and computed positions These values are larger for the unknown station as we will see. Time interval to multiply times velocity = decimal year at mid-pt of session minus 1997.0000 = 8.1597 yrs

35. OPUS Extended Output: Remote Station Information The initial ITRF xyz position for the station being solved for is displayed for the mid-point of the observation time span. A similar position is obtained for the L1 phase center based on the antenna type selected. REMOTE STATION INFORMATION STATION NAME: corv 1 ANTENNA: ASH700936B_M SNOW S/N=UNKNOWN XYZ -2498422.0030 -3802821.7980 4454738.6350 MON @ 2005.1595 (M) NEU -0.0000 -0.0000 -0.0001 MON TO ARP (M) NEU 0.0000 0.0000 0.1081 ARP TO L1 PHASE CENTER (M) NEU 0.0000 0.0000 0.1256 ARP TO L2 PHASE CENTER (M) XYZ 0.0000 0.0001 -0.0001 MON TO ARP XYZ -0.0423 -0.0643 0.0759 ARP TO L1 PHASE CENTER XYZ -2498422.0452 -3802821.8623 4454738.7108 L1 PHS CEN @ 2005.1596 The antenna height is 0.000 here because we are solving for the Antenna Reference Point position. Typically, however, you will have entered a non-zero antenna height.

36. OPUS Extended Output: Remote Station cont  Final positions based on this first vector. The XYZ adjustments are the difference between the initial and final positions. XYZ -2498422.0452 -3802821.8623 4454738.7108 L1 PHS CEN @ 2005.1596 BASELINE NAME: newp corv XYZ -1.8831 0.9528 -0.8303 + XYZ ADJUSTMENTS XYZ -2498423.9283 -3802820.9095 4454737.8805 NEW L1 PHS CEN @ 2005.1596 XYZ -2498423.8860 -3802820.8451 4454737.8047 NEW ARP @ 2005.1596 XYZ -2498423.8861 -3802820.8452 4454737.8047 NEW MON @ 2005.1596 LLH 44 35 7.92693 236 41 43.42403 107.2364 NEW L1 PHS CEN @ 2005.1596 LLH 44 35 7.92693 236 41 43.42403 107.1283 NEW ARP @ 2005.1596 LLH 44 35 7.92693 236 41 43.42403 107.1284 NEW MON @ 2005.1596 Preliminary ITRF coordinates for the remote station incorporating velocities computed for mid-point of session in the previous section  Final remote station ITRF latitude, longitude and ellipsoid height for this vector. Similar for the two remaining vectors. The first of 3 baselines being solved

37. OPUS Extended Output: gfiles G-FILES Axx2005 228 5 228 B2005 228 5 0 5 228 659 1 page5 v0411.19IGS 222 1 2 27NGS 2006 110IFDDFX Iant_info.003 NGS 20060110 C00090001 -500301992 15 333712066 21 -1012864 25 X0595ACORVX0595ANEWP D 1 2 8074967 1 3 -8657359 2 3 -8955936 Axx2005 228 5 228 B2005 228 5 0 5 228 659 1 page5 v0411.19IGS 222 1 2 27NGS 2006 110IFDDFX Iant_info.003 NGS 20060110 C00090002 -49126271 27 884134550 32 707170134 51 X0595ACORVX0595ACHZZ D 1 2 8158782 1 3 -8510487 2 3 -7117245 Axx2005 228 5 228 B2005 228 5 0 5 228 659 1 page5 v0411.19IGS 222 1 2 27NGS 2006 110IFDDFX Iant_info.003 NGS 20060110 C00090003 286169924 13 144722673 17 281156013 20 X0595ACORVX0595AP376 D 1 2 9256643 1 3 -6469194 2 3 -7978592 Each of the three baselines has a section of A, B, I, C and D records. The specific record formats are listed in Bluebook Annex N, http://www.ngs.noaa.gov/FGCS/BlueBook/pdf/Annex_N.pdf. The C record contains dx, dy, dz vector components and related standard deviations. The D record contains correlations. The gfiles can be combined to do NGS-style adjustment with gfile and bfile (next slide). http://www.ngs.noaa.gov/FGCS/BlueBook/pdf/Annex_N.pdf

38. OPUS Extended Output: user-constructed composite gfile Axx2005 228 5 228 **first session, first vector:** B2005 3 117 0 5 3 11859 1 page5 v0601.10IGS 222 1 2 27NGS 2006 113IFDDFX Iant_info.003 NGS 20060113 C00090001 -500302065 15 333712070 20 -1012813 24 X0605ACORVX0605ANEWP D 1 2 7430190 1 3 -8143037 2 3 -9277350 **first session, second vector:** B2005 3 117 0 5 3 11859 1 page5 v0601.10IGS 222 1 2 27NGS 2006 113IFDDFX Iant_info.003 NGS 20060113 C00090002 -49126038 18 884134654 28 707169927 35 X0605ACORVX0605ACHZZ D 1 2 8612299 1 3 -8840443 2 3 -8385989 **first session, third vector:** B2005 3 117 0 5 3 11859 1 page5 v0601.10IGS 222 1 2 27NGS 2006 113IFDDFX Iant_info.003 NGS 20060113 C00090003 286169906 13 144722682 18 281156043 24 X0605ACORVX0605AP376 D 1 2 8779188 1 3 -7118769 2 3 -8693288 **second session, first vector:** B2005 6 117 0 5 6 11859 1 page5 v0601.10IGS 222 1 2 27NGS 2006 113IFDDFX Iant_info.003 NGS 20060113 C00090001 -500301975 13 333712099 17 -1012891 20 X1525ACORVX1525ANEWP D 1 2 7783139 1 3 -8265107 2 3 -9194771 **second session, second vector:** B2005 6 117 0 5 6 11859 1 page5 v0601.10IGS 222 1 2 27NGS 2006 113IFDDFX Iant_info.003 NGS 20060113 C00090002 -49126063 14 884134679 20 707169869 26 X1525ACORVX1525ACHZZ D 1 2 8654983 1 3 -8471449 2 3 -7513444 **second session, third vector:** B2005 6 117 0 5 6 11859 1 page5 v0601.10IGS 222 1 2 27NGS 2006 113IFDDFX Iant_info.003 NGS 20060113 C00090003 286169960 14 144722734 18 281155938 22 X1525ACORVX1525AP376 D 1 2 9047597 1 3 -7018973 2 3 -8300669 Example of two occupations of a station. Gfile constructed by deleting all but first “Axx2005…” lines from the extended output, then appending the two baselines’ gfiles to the first one, then adding second session results to the first session. Extra lines inserted to show file structure

39. OPUS Extended Output: Post-fit RMS…. POST-FIT RMS BY SATELLITE VS. BASELINE OVERALL 01 04 11 13 14 16 20 23 newp-corv| 0.013 0.013 0.030 0.009 0.015 0.022 0.011... 0.007 24 25 newp-corv| 0.015 0.008 NGS’ baseline processor “PAGES” (Program for the Adjustment of GPS Ephemerides) develops statistics such as the above to aid in analyzing solution quality. In the spirit of automated processing that is fundamental to OPUS, there is no option to disable specific satellites. Each baseline has a section like the one shown above.

40. OPUS Extended Output: Observations summary OBS BY SATELLITE VS. BASELINE OVERALL 01 04 11 13 14 16 20 23 newp-corv| 1482 239 57 158 127 32 162... 237 24 25 newp-corv| 231 239 OVERALL 01 04 11 13 14 16 20 23 chzz-corv| 1260 128 65 149 125... 117... 238 24 25 chzz-corv| 218 220 OVERALL 01 04 11 13 14 16 20 23 p376-corv| 1486 239 67 156 129 35 163... 238 24 25 p376-corv| 220 239 Each baseline has a summary of the observations received from each satellite. OBS USED: 4228 / 4314 : 98% As discussed on slides 14 & 15 (Reading OPUS output, Guidelines for Good Solution), the Standard Output summarizes the total percent of observations used over all three baselines.

41. OPUS Extended Output: Covariance Matrices Covariance Matrix for the xyz OPUS Position (meters2). 0.0000024956 0.0000002586 -0.0000003699 0.0000002586 0.0000038978 -0.0000004229 -0.0000003699 -0.0000004229 0.0000080578 Covariance Matrix for the enu OPUS Position (meters2). 0.0000026809 -0.0000004333 0.0000003326 -0.0000004333 0.0000053747 0.0000021840 0.0000003326 0.0000021840 0.0000063955 Horizontal network accuracy = 0.00500 meters. Vertical network accuracy = 0.00496 meters. Additional statistics developed by PAGES for use in commercial adjustment software: Diagonal elements: Variance of x:0.0000024956 Variance of y: 0.0000038978 Variance of z: 0.0000080578 Off-diagonal elements: Covariance of x-y: 0.000002586 Covariance of x-z: -0.0000003699 Covariance of y-z: -0.0000004229 Similar for enu. Estimates of network accuracy. These may be optimistic here, given that peak-peak errors are in the 1-3 cm range.

42. OPUS Extended Output: NAD 83 quantities Derivation of NAD 83 vector components Position of reference station ARP in NAD_83(CORS96)(EPOCH:2002.0000). Xa(m) Ya(m) Za(m) NEWP -2548453.96133 -3769451.68039 4454637.42077 2002.00 CHZZ -2503335.82617 -3714408.62715 4525454.72998 2002.00 P376 -2469806.16816 -3788349.79220 4482853.31622 2002.00 Position of reference station monument in NAD_83(CORS96)(EPOCH:2002.0000). Xr(m) Yr(m) Zr(m) NEWP -2548453.39333 -3769450.84019 4454636.42117 2002.00 CHZZ -2503335.79517 -3714408.58125 4525454.67368 2002.00 P376 -2469806.16496 -3788349.78730 4482853.31032 2002.00 Velocity of reference station monument in NAD_83(CORS96)(EPOCH:2002.0000). Vx (m/yr) Vy (m/yr) Vz (m/yr) NEWP 0.01180 0.00240 0.00600 CHZZ 0.00550 -0.00410 0.00200 P376 0.00440 0.00380 0.00560 Vectors from unknown station monument to reference station monument in NAD_83(CORS96)(EPOCH:2002.0000). Xr-X= DX(m) Yr-Y= DY(m) Zr-Z= DZ(m) NEWP -50030.22533 33371.21181 -101.27783 2002.00 CHZZ -4912.62717 88413.47075 70716.97468 2002.00 P376 28617.00304 14472.26470 28115.61132 2002.00 The above quantities are derived by transformation from similar ITRF quantities.

43. OPUS Extended Output: SPC—Disclaimer--End STATE PLANE COORDINATES - International Foot SPC (3601 OR N) Northing (Y) [feet] 347675.709 Easting (X) [feet] 7471572.785 Convergence [degrees] -1.98897497 Point Scale 0.99994603 Combined Factor 0.99992918 This position and the above vector components were computed without any knowledge by the National Geodetic Survey regarding the equipment or field operating procedures used. State Plane Coordinate quantities Disclaimer End of OPUS Extended Output. Next: example of adjusting several sessions submitted to OPUS for the same station

44. Files for sample adjustment Upper part of skeleton Bfile (no *25*, *27*, *70*, *72* records): 000010*OR*HZTLOBS NGS NATIONAL GEODETIC SURVEY 20060112 000020*10*TEST OPUS SOLUTIONS TO CORVALLIS CORS 000030*12*200502200502JROJEFF OLSEN 000040*13*NORTH AMERICAN DATUM-83 GRS-80 63781370002982572221 *80*0001NEWPORT CORS ARP 44350607244N124034273663W ORAA *86*0001 N88 A A *80*0002CAPE MEARS CORS ARP 45291143774N123584118743W ORAA *86*0002 N88 A A (*80* and *86* records for two stations not shown) 025640*OR* Serfil : NEWP 0001 CHZZ 0002 P376 0003 CORV 0009 DDSN 0005 Upper Part of composite Gfile. Four 2-hr sessions for CORV at different times of 2005 were sent to OPUS. Vectors for one of the four sessions shown. Axx2005 228 5 228 B2005 3 117 0 5 3 11859 1 page5 v0601.10IGS 222 1 2 27NGS 2006 113IFDDFX Iant_info.003 NGS 20060113 C00090001 -500302065 15 333712070 20 -1012813 24 X0605ACORVX0605ANEWP D 1 2 7430190 1 3 -8143037 2 3 -9277350 B2005 3 117 0 5 3 11859 1 page5 v0601.10IGS 222 1 2 27NGS 2006 113IFDDFX Iant_info.003 NGS 20060113 C00090002 -49126038 18 884134654 28 707169927 35 X0605ACORVX0605ACHZZ D 1 2 8612299 1 3 -8840443 2 3 -8385989 B2005 3 117 0 5 3 11859 1 page5 v0601.10IGS 222 1 2 27NGS 2006 113IFDDFX Iant_info.003 NGS 20060113 C00090003 286169906 13 144722682 18 281156043 24 X0605ACORVX0605AP376 D 1 2 8779188 1 3 -7118769 2 3 -8693288 Afile : CC 0001 44350607244N124034273663W 20780E DD3 II 599999 (Coordinates and EH for NEWP constrained) MM3NYfrebbk

45. Adjustment statistics NATIONAL GEODETIC SURVEY PROGRAM ADJUST ADJUSTMENT PROGRAM PAGE 15 VERSION 4.30 N RMS MEAN ABS CONTRIB. RESIDUAL RESIDUAL NORTH 11 0.003 0.002 (METERS) EAST 11 0.002 0.001 (METERS) UP 11 0.008 0.006 (METERS) DEGREES OF FREEDOM = 24 VARIANCE SUM = 234.6 STD.DEV.OF UNIT WEIGHT = 3.126 VARIANCE OF UNIT WEIGHT = 9.77

46. Output Bfile Bfile from free adjustment : 000010*CO*HZTLOBS NGS NATIONAL GEODETIC SURVEY 20060112 000020*10*TEST OPUS SOLUTIONS TO CORVALLIS CORS 000030*12*200502200502JROJEFF OLSEN 000040*13*NORTH AMERICAN DATUM-83 GRS-80 63781370002982572221 *80*0001NEWPORT CORS ARP 44350607244N124034273663W ORAA *86*0001 N88 20780A A *80*0002CAPE MEARS CORS ARP 45291143836N123584118793W ORAA *86*0002 N88 51097A A *80*0003EOLARESVR OR2004 CORS ARP 44562831336N123060810210W ORAA *86*0003 N88 181245A A *80*0009CORV CORS ARP BY OPUS 44350791052N123181651975W ORAA ( Pub =.91082,.51926) *86*0009 N88 107516A A ( Pub = 107.514) *80*0005DDSN 43070763047N123143921370W ORAA *86*0005 N88 953585A A 025640*AL* (No orthometric or geoid heights computed in this example)

47. Example of using HTDP from NGS Tool Kit NEWP position computed for day of year 059, 2005

48. Recommended background reading Coordinate Systems A series of four papers about Terrestrial Reference Systems Snay, R.A. & T. Soler (1999). Part 1 - Modern Terrestrial Reference Systems. Professional Surveyor, 19(10), 32-33.(1999) Snay, R.A. & T. Soler (2000). Part 2 - The evolution of NAD83. Professional Surveyor, 20(2), 16, 18.(2000) Snay, R.A. & T. Soler (2000). Part 3 - WGS 84 and ITRS. Professional Surveyor, 20(3), 24, 26, 28.(2000) Snay, R.A. & T. Soler (2000). Part 4 - Practical considerations for accurate positioning. Professional Surveyor, 20(4), 32-34.(2000)

49. Recommended background reading

50. GPS dataObservation log OPUS-DB (OPUS-DataBase) description formphoto(s) NGS website: OPUS-DB NGS DATABASE NGS magic

51. online positioning user service OPUS www.ngs.noaa.gov/OP US / your position your GPS data IERS geophysical models IGS satellite orbits ITRF reference frames NGS antenna calibrations NGS CORS base stations NGS geodetic toolkit NGS site information files UNAVCO teqc conversion (optional) publish in NGS database calibrated antenna type mark info (optional) JGE 2008v3 geodetic data

52. Report options + extended report + XML report + select state plane Share options + add to database + add to campaign Process options + set user profile + select CORS + select software

53. OPUS solutions meeting certain criteria and accompanied by metadata describing the site may be eligible for publication on Data Sheets from the NGS Integrated Data Base (IDB). Users submitting to the IDB must be registered with NGS to receive a user ID and password and agree to the terms of this publication. Please review the procedures for IDB submission.criteriaprocedures “ OPUS DB” (Submitting OPUS Results) The numerical criteria for an OPUS solution to be accepted for publication are: NGS calibrated GPS antenna minimum 4 hour data span minimum 70% observations used minimum 70% fixed ambiguities maximum 0.04m horizontal peak-to-peak maximum 0.08m vertical peak-to-peak

54. “OPUS Projects”—under long-term development OPUS files identified as belonging to a project are directed to appropriate directories Project data submission organized Reports sent to project managers Station data checked and edited as needed PAGES GPS processing accomplished ADJUST run

55. Demonstration Application II

56. CONTROLLING A BRIDGE SURVEY The accompanying slides were presented at the 2002 CORS Forum by Gary Thompson of the North Carolina Geodetic Survey.

57. Using OPUS to control Bridges On a typical bridge job, NCDOT Sets an azimuth pair ( ) Uses approximately 6-7 control panels ( ) Controls the site with 2 receivers

58. P1 P2 P3 P4 P5 P6 TIP: B-9999 B9999-1B9999-2 Place the Base Station over your first point and begin RTK survey ensuring that you are collecting Raw Data for at least 2 hours (This data will be sent to OPUS). We will now refer to this as OPUS1. Start Rover and begin setting and controlling your panels Be sure to measure to opposite Azimuth Pair point.

59. B9999-1B9999-2 P1 P2 P3 P4 P5 P6 TIP: B-9999 Again, Be sure to measure to opposite Azimuth Pair point. Move the Base Station over your second point and begin RTK survey ensuring that you are collecting Raw Data for 2 hours. (This data will also be sent to OPUS). We will now refer to this as OPUS2. Start Rover and begin controlling your panels from the second location. If you use one controller and name the points the same the controller will provide comparisons in the field.

60. Field Work is now complete. The following steps need to be taken to finish the process:

61. Office Process Download the Raw Data and RTK dc files Convert both blocks of raw data to RINEX format using Trimble’s utility Upload the files to: http://www.ngs.noaa.gov/OPUS/ http://www.ngs.noaa.gov/OPUS/ Receive the results from OPUS via email in minutes

62. Continued... Import the dc file into Trimble Geomatics Office Update the initial base position for the first base to the coordinates provided by OPUS1 After a recompute, everything in the dc file should be corrected relative to the first base location (OPUS1)

63. Continued... The position for OPUS2 is only used for comparison to what was derived from OPUS1 Coordinates can now be utilized as needed

64. OPUS & RTK Savings to NCDOT Cell PhonesGPS ReceiversVehiclesStaff Hours 2 1 3 18 - 36 6 - 12 24 - 48 Savings OPUS & RTK Static 3 3 2 1 *1 2 *The cell phone listed in the OPUS & RTK surveying comparison was not used in the survey work, but was available for contacting the office.

65. HOW IS THE ANTENNA HEIGHT MEASURED? ARP MARK The height is measured vertically (NOT the slant height) from the mark to the ARP of the antenna. The height is measured in meters. The ARP is almost always the center of the bottom-most, permanently attached, surface of the antenna. See GPS Antenna Calibration for photo’s and diagrams that show where the ARP is on most antennas: http://www.ngs.noaa.gov/ANTCAL / If the default height of 0.0000 is entered, OPUS will return the position of the ARP.

66. WHY DO I NEED THE ANTENNA TYPE? The antenna phase centers are located somewhere around here. The Antenna Reference Point (ARP) is almost always located in the center of the bottom surface of the antenna. The antenna offsets are the distance between the phase centers and the ARP If the user selects NONE as the antenna type, the offsets are set to 0.000 and the antenna phase center becomes the reference You do not need to know these offsets. They are passed to the processing software through the antenna type Incorrect or missing antenna type  big vertical errors

67. Antenna Calibration Facility in Corbin, Virginia

68. Note that SV elevation and varying phase patterns affect signal interpretation differently........................ SV 14 SV 20 Antenna Type A Antenna Type B Antenna Phase Center Variation

69. ........................ SV 14 SV 20 Antenna Type A Antenna Type B Different Phase Patterns Note that SV elevation and varying phase patterns affect signal interpretation differently Antenna Phase Center Variation

70. ELECTRONIC PHASE CENTER Elevation Angle (deg.) Phase Center Variation (mm)

71. Recent solutions

72. Files processed during even-numbered months, 2002-2005

73. Files processed during even-numbered months, 2002-2007

74. OPUS usage for one month

75. Total OPUS usage during 2005

76. ONGOING CORS RESEARCH * Exploring the use of NTRIP to stream GPS data from selected CORS via the Internet. * Developing OPUS-GIS which will process a few minutes of GPS code range data (for sub-meter accuracy) * Improving OPUS-RS (rapid static) that will enable users to obtain positional coordinates with cm-level accuracy using only 15 minutes of GPS carrier phase data

77. “OPUS Projects”—under long-term development OPUS files identified as belonging to a project are directed to appropriate directories Project data submission organized Reports sent to project managers Station data checked and edited as needed PAGES GPS processing accomplished ADJUST run

78. 10 minute break Next Presentation: OPUS-Database