Kansas Land Surveyors Conference

1. Kansas Land Surveyors Conference OPUS, OPUS-RS, and OPUS-DB Dave Zenk NGS Advisor October 29, 2010 Wichita, KS

2. What is OPUS? • OPUS is an acronym for: • Online Positioning User Service (OPUS) • It started as a service for Static GPS users and has grown from there to serve other users. • Designed to work with minimal data input from user and be as fully automated as possible. • Only a Web Browser and Email needed to use. • Fast, easy, consistent access to NSRS.

3. Many Flavors of OPUS Planned • OPUS-S (static) • $$$ receiver, hours of data • OPUS-RS (rapid static) • $$$ receiver, minutes of data • OPUS-DB (database) • $$$ receiver, hours of data, share results • OPUS-Projects – not released • Multiple $$$ receivers, share results • OPUS-GIS – not released • ¢¢ receiver, minutes of data • OPUS-Leveling – not released

4. OPUS has been popular

5. OPUS has been popular

6. Areas covered by OPUS

7. Areas covered by OPUS

8. Areas covered by OPUS

9. How does OPUS work? • Each OPUS ‘flavor’ is a bit different • Let’s start with OPUS-S • Then, we’ll highlight the differences in • OPUS-RS • OPUS-DB • OPUS-Projects

10. OPUS-S • OPUS-Static, (formerly just called OPUS and sometimes now called OPUS-CLASSIC) • Basic Steps • Submit GPS data to OPUS Web site • Processed automatically on NGS computers • Ties to 3 CORS stations • Solution via email - in minutes • Fast, easy, consistent access to NSRS

11. OPUS Guidelines • Email address for results • Data file with 2 hrs to 48 hrs of GPS L1/L2 data • Static GPS observations only • 30-second epochs processed • not approved for less than 2 hrs of data, but you can try • Antenna type/phase model • Antenna height from mark-to-ARP vertical

12. OPUS Website (all flavors) • http://www.ngs.noaa.gov/OPUS/

13. OPUS Screen Layout e-mail GPS file antenna type antenna height options OPUS-S (2 hr) OPUS-RS (15 min)

14. OPUS Inputs • Email – dave.zenk@noaa.gov • GPS file - .dat or Rinex (.obs) • you may zip several files together • IF they all have same antenna type and antenna height. • Antennas need not be same serial numbers • Antenna Type – TRM41249.00 (choose from list) • Antenna Ht – vertical measure from mark to ARP • Options – next 2 slides…

15. OPUS Inputs (OPTIONS 1 & 2) specify SPCS specify CORS

16. OPUS Inputs (OPTIONS 3, 4, & 5) Specify GEOID model: Auto GEOID09 GEOID03 Choose OUTPUT type Choose XML or not

17. OPUS Inputs (OPTIONS 6, 7, & 8) OPUS-Projects Keyword Set USER Profile Choose PUBLISH and Submit

18. Antenna Height • true vertical distance • measured in meters ARP MARK

19. CORS B CORS A + CORS C OPUS Positions • NGS PAGES processing software • Ionospheric-free solution • Tropospheric scale height adjusted • Fixed ambiguities • Average of 3 unique CORS ties • ITRF & NAD83 coordinates/errors Average

20. OPUS Report

21. OPUS Report – check results • > 90% observations used • > 50% ambiguities fixed • < 3 cm overall RMS • check ephemeris type • check antenna info • < 5 cm peak-to-peak errors …and which CORS were used? … resubmit later for better CORS scenario & ephemeris

22. OPUS Extended Output • HTDP-transform CORS ITRF coordinates from published epoch to session midpoint • remote station ITRF solution from each CORS • G-files – vector components, standard deviations, & correlations for each vector • post-fit RMS & # observations per satellite/vector • solution covariance matrix-relates errors in each coordinate to every other coordinate • network accuracies - H & V • summary of NAD83 derivation • SPC feet values, if available for user’s state

23. OPUS-RS (Rapid Static) • 15-minute sessions minimum, 4 hr maximum • ties to 3 – 9 CORS (< 250km) • uses RSGPS vs. PAGES software • P1/P2 code & L1/L2 phase observations • resolves all ambiguities with LAMBDA • similar to Real-Time Network computations • RSGPS solution modes: • network: solves ambiguities, tropo, iono • rover: tropo and ion interpolated to rover • ~10,000 lines of code

24. Don’t use OPUS-RS outside areas where insufficient CORS exist. OPUS-RS geographical coverage (15 minute session)

25. OPUS-RS geographical coverage (60 minute session) • Don’t use OPUS-RS outside areas where insufficient CORS exist.

26. OPUS-RS Output NGS OPUS-RS SOLUTION REPORT     USER: william.stone@noaa.gov                 DATE: October 29, 2007 RINEX FILE: 1207287x.07o                         TIME: 14:39:04 UTC  SOFTWARE: rsgps  1.09 RS11.prl 1.12     START: 2007/10/14 23:27:15 EPHEMERIS: igr14490.eph [rapid]                     STOP: 2007/10/15 00:00:15 NAV FILE: brdc2870.07n                        OBS USED:   1962 /  2082   :  94% ANT NAME: ASH701975.01A                 QUALITY IND.   34.21/ 37.91 ARP HEIGHT: 0.0                           NORMALIZED RMS: 0.307  REF FRAME: NAD_83(CORS96)(EPOCH:2002.0000)    ITRF00 (EPOCH:2007.78627)     LAT: 36  2 52.79767      0.008(m)       36  2 52.81498     0.008(m)      E LON:   252  2 18.45532    0.013(m)       252  2 18.41156     0.013(m)      W LON:   107 57 41.54468  0.013(m)       107 57 41.58844     0.013(m)      EL HGT:         1974.304(m)   0.005(m)       1973.396(m)   0.005(m)  ORTHO HGT:         1995.280(m)   0.026(m) [Geoid03 NAVD88] * • “#Fixed Ambiguities” replaced by “Quality Indicator” • average of W-ratio (separation between candidate sets of ambiguities) of last 3 epochs • reported as network mode / rover mode • look for values > 3 for confidence in solution

27. OPUS-RS Output NGS OPUS-RS SOLUTION REPORT     USER: william.stone@noaa.gov                 DATE: October 29, 2007 RINEX FILE: 1207287x.07o                         TIME: 14:39:04 UTC  SOFTWARE: rsgps  1.09 RS11.prl 1.12     START: 2007/10/14 23:27:15 EPHEMERIS: igr14490.eph [rapid]                     STOP: 2007/10/15 00:00:15 NAV FILE: brdc2870.07n                        OBS USED:   1962 /  2082   :  94% ANT NAME: ASH701975.01A                 QUALITY IND.   34.21/ 37.91 ARP HEIGHT: 0.0                           NORMALIZED RMS: 0.307  REF FRAME: NAD_83(CORS96)(EPOCH:2002.0000)    ITRF00 (EPOCH:2007.78627)     LAT: 36  2 52.79767      0.008(m)       36  2 52.81498     0.008(m)      E LON:   252  2 18.45532    0.013(m)       252  2 18.41156     0.013(m)      W LON:   107 57 41.54468  0.013(m)       107 57 41.58844     0.013(m)      EL HGT:         1974.304(m)   0.005(m)       1973.396(m)   0.005(m)  ORTHO HGT:         1995.280(m)   0.026(m) [Geoid03 NAVD88] * • “Overall RMS” replaced by “Normalized RMS” • unitless quantity, “expected” = 1 • aka standard deviation of unit weight • if > 1, noisy data somewhere • typically <1, meaning noise less than expected

28. OPUS-RS Output NGS OPUS-RS SOLUTION REPORT     USER: william.stone@noaa.gov                 DATE: October 29, 2007 RINEX FILE: 1207287x.07o                         TIME: 14:39:04 UTC  SOFTWARE: rsgps  1.09 RS11.prl 1.12     START: 2007/10/14 23:27:15 EPHEMERIS: igr14490.eph [rapid]                     STOP: 2007/10/15 00:00:15 NAV FILE: brdc2870.07n                        OBS USED:   1962 /  2082   :  94% ANT NAME: ASH701975.01A                 QUALITY IND.   34.21/ 37.91 ARP HEIGHT: 0.0                           NORMALIZED RMS: 0.307  REF FRAME: NAD_83(CORS96)(EPOCH:2002.0000)    ITRF00 (EPOCH:2007.78627)     LAT: 36  2 52.79767      0.008(m)       36  2 52.81498     0.008(m)      E LON:   252  2 18.45532    0.013(m)       252  2 18.41156     0.013(m)      W LON:   107 57 41.54468  0.013(m)       107 57 41.58844     0.013(m)      EL HGT:         1974.304(m)   0.005(m)       1973.396(m)   0.005(m)  ORTHO HGT:         1995.280(m)   0.026(m) [Geoid03 NAVD88] * * • Peak-to-Peak replaced by Est. Standard Deviations • approximately 95% confidence • derived from scatter of single baseline solutions • formal standard deviations (optimistic) available in Extended Output

29. OPUS-RS Station Selection

30. OPUS-RS Interpolative Dilution of Precision (IDOP) OPUS-RS accuracy is dictated by CORS geometry and distances IDOP = local CORS geometry relative to rover location [min = 1/sqrt(#CORS)] RMSD – CORS distances * Forthcoming paper in “GPS Solutions” – Accuracy Assessment of the NGS’s OPUS-RS Utility By C. Schwarz, R. Snay, & T. Soler

31. Expected OPUS-RS Standard Error Values in E or N Dimension:

32. OPUS-RS Usage

33. OPUS-RS Questions

34. OPUS-DB (database) • OPUS-DB recently let loose “in the wild” • Means you can use it now • Intended to be a way for surveyors to • access NSRS, • maintain the existence of the mark, and • optionally share results with others. • Works with OPUS or OPUS-RS

35. OPUS-DBhttp://www.ngs.noaa.gov/OPUS/

36. OPUS-DB

37. OPUS-DB --- 3 Tabs • Upload • Similar to other OPUS flavors • View • use to retrieve marks from the database • About • wealth of detail on OPUS system

38. OPUS-DB Upload

39. OPUS-DB Upload/Option #7

40. OPUS-DB Upload/Option #7 • Choose YES, Publish or NO, Don’t Publish • The NO option is same as OPUS-S or OPUS-RS • The YES option followed by a choice of OPUS-S or OPUS-RS button will bring up a Step 2 screen to identify your mark… • Either Describe NEW or Describe Recovered Mark or Abort

41. OPUS-DB Step 2

42. OPUS-DB Step 3 • If you choose NEW, you must fill in the required fields and have 2 photos (small .jpg files) • If you choose Existing you need to know the mark identity (PID)

43. OPUS-DB Step 3 existing mark

44. OPUS-DB Step 3 new mark

45. OPUS-DB Step 4

46. OPUS-DB Approval Email “The following contribution has been submitted to OPUS for publication in the OPUS Database. Please visit the link below to verify that the information you provided is correctly presented on the new datasheet. When the datasheet is viewed, two buttons will be displayed at the top of the new datasheet web page. Please select the appropriate button to accept or withdraw your contribution. An action must be taken for the datasheet to be published or withdrawn.” The OPUS Team. RINEX FILE: DESIGNATION: BARB RESET http://beta.ngs.noaa.gov/OPUS/getFeedback.jsp?id=000478336

47. OPUS-DB Final Approval and Sample Datasheet Last Chance to Abort

48. OPUS-DB Usage

49. Recent OPUS Results on a Real Project • USGS is monitoring the long term effects of an oil spill in northern Minnesota. • They had been using an assumed basis of coordinates for horizontal and vertical surveys. • Their GIS analyst was having trouble combining the data with other maps in the area. • They asked for NGS help in getting connected to the NSRS.

50. Recent OPUS Results on a Real Project • We decided that the best end result would be • Bluebooked First Order horizontal project (GPS) • Bluebooked Second Order Class 1 vertical (leveling) • But, we also wanted to compare OPUS and OPUS-RS results.