1. U.S. Department of the Interior U.S. Geological Survey Height Modernization Coordination Meeting Paul H. Rydlund Jr. PLS U.S. Geological Survey Missouri Water Science Center  USGS Publication For Vertical Control Vertical Control  Inter-agency Datum Establishment And Conversion Collaboration In Missouri In Missouri

2. USGS GNSS T&M – Why? Technique and Approach Guidance For USGS Technique and Approach Guidance For USGS Accuracy and Precision Accuracy and Precision Metadata Metadata Example Campaigns and Decision Trees Example Campaigns and Decision Trees Future Direction Future Direction Consistent and Referable Consistent and Referable The Black Box Global Navigation Satellite System “With the new Trimble R8 systems, we are getting vertical accuracies within 7 mm as stated in the data collector “ “RTK can only be used when setting up directly over a benchmark “ “Real-Time Network surveys pretty much guarantee vertical accuracies within 2 cm and you never need a base station “ “All post processing GPS surveys must ensure 6 hours of data collection at a minimum“

3. USGS GNSS T&M - Introduction Historic USGS Datum Establishment Historic USGS Datum Establishment Evolution Evolution GPS Modernization GPS Modernization GNSS GLONASS, Galileo, Compass GNSS GLONASS, Galileo, Compass Geodesy Background Geodesy Background

4. GNSS T&M - Equipment

6. USGS GNSS T&M - Mission Planning PDOP PDOP Multipath Multipath Ionosphere & Troposphere Ionosphere & Troposphere Satellite Availability ( Notice Advisory To Navstar Users) Satellite Availability ( Notice Advisory To Navstar Users) Space Weather ( Space Weather Prediction Center) Space Weather ( Space Weather Prediction Center) Resolution and Accuracy of Local Geoid Resolution and Accuracy of Local Geoid Troposphere Ionosphere < 10 km > 10 km LOOKOUT FOR THESE

7. GNSS T&M – Real Time (RT) Surveys Single Base RTSingle Base RT Network Base RTNetwork Base RT

8. GNSS T&M – Real Time (RT) Surveys Quality AssurancesQuality Assurances Blunder Check 1.Multipath and General 2.Height 3.Reinitialization Blunder Check - Let’s sum it up! Collectively, the GNSS user observes 180 epochs or 3 minutes of data, walks away from the objective point a minimum of 100 feet, inverts the rover receiver (or adjusts the elevation mask) to lose initialization, changes the rover rod height at least 0.80 feet and corrects the rover height entered in the data collector appropriately, walks a different approach path back to the objective point, then positions the rover receiver in an upright position over the objective point for the second observation. Both observations are averaged to produce the final result. This process is hereinafter referred to as a RT blunder check and should be recorded in the field notes to document that these redundant assurances are met.

9. GNSS T&M – Real Time (RT) Surveys Localizations / RealizationsLocalizations / Realizations

10. USGS GNSS T&M – Post Processed Single Base – OPUS Single Base – OPUS Traditional Static Traditional Static Rapid Static Rapid Static The experts in geodesy. The USGS GNSS T&M Manual recommends and encourages use of this online utility

11. USGS GNSS T&M – Post Processed Network SurveysNetwork Surveys Quality AssurancesQuality Assurances Modified from NOS NGS 59 Tech Memo

12. USGS GNSS T&M – Quality Categorization Level I – Static Network Survey Level I – Static Network Survey Control Control 40 Km spacing; 4 hour; 2 nd order or better 40 Km spacing; 4 hour; 2 nd order or better Objective Objective 15 Km spacing; 1 hour; 50% double occupied 15 Km spacing; 1 hour; 50% double occupied Additional benchmark checks other than primary control Additional benchmark checks other than primary control Level I – Static Single Base Survey (OPUS-S) Level I – Static Single Base Survey (OPUS-S) Occupation Occupation 2 Days, 4 hours, different times 2 Days, 4 hours, different times Quality Indicators Quality Indicators

13. USGS GNSS T&M – Quality Categorization Level II – Static Network Survey Level II – Static Network Survey Control Points Control Points 60 Km spacing; 4 hour; 2 nd order or better 60 Km spacing; 4 hour; 2 nd order or better Objective Points Objective Points 25 km spacing; 1 hour; 50% double occupied 25 km spacing; 1 hour; 50% double occupied Additional benchmark checks other than primary control Additional benchmark checks other than primary control Level II – Static Single Base Survey (OPUS-S) Level II – Static Single Base Survey (OPUS-S) Occupation 1 day – 4 hours Occupation 1 day – 4 hours Quality Indicators Quality Indicators Level II – RT Surveys Level II – RT Surveys Localization – 2 nd order or better Localization – 2 nd order or better Satellites; PDOP; baseline length Satellites; PDOP; baseline length Blunder check redundancy within 0.03 m Blunder check redundancy within 0.03 m Objective points 10% double occupied (within 0.05m) Objective points 10% double occupied (within 0.05m)

14. USGS GNSS T&M – Quality Categorization Level III – Static Single Base Survey (OPUS-S) Level III – Static Single Base Survey (OPUS-S) Quality Indicators Quality Indicators Level III – Static Single Base Survey (OPUS-RS) Level III – Static Single Base Survey (OPUS-RS) Quality Indicators Quality Indicators Level III – RT Surveys Level III – RT Surveys Localization – 3 rd order or better Localization – 3 rd order or better Satellites; PDOP; baseline length Satellites; PDOP; baseline length Blunder check redundancy within 0.04 m Blunder check redundancy within 0.04 m Objective points 10% double occupied; within 0.05m Objective points 10% double occupied; within 0.05m

15. USGS GNSS T&M – Quality Categorization Level IV Level IV Generally reserved for RT topographic surveys without checks Generally reserved for RT topographic surveys without checks Can be composed of static surveys without quality indicators or checks Can be composed of static surveys without quality indicators or checks

16. USGS GNSS T&M – Quality “How Do We Get There?”

17. USGS GNSS T&M – Metadata (documentation of the geodetic trail) Recovery Establishment Benchmark Benchmark

18. USGS GNSS T&M – Metadata (documentation of the geodetic trail) Observation Observation Database storage Database storage lat-long and altitude lat-long and altitude metadata metadata

19. USGS GNSS T&M – Example Data Set (Groundwater Well Field)

20. USGS GNSS T&M – Example Data Set (Flood Study)

21. USGS GNSS T&M – Example Data Set (Streamgage Datum)

22. USGS GNSS T&M – Future Direction of GNSS Modernization programs – L5 signal Modernization programs – L5 signal GRAV-D GRAV-D Precise Point Positioning (PPP) Precise Point Positioning (PPP)

23. Plug for USGS – GPS Committee http://water.usgs.gov/usgs/osw/gps/

24. Office of Employee Development (OED) ID1747 Application and Practice of Survey-Grade GNSS Real-Time and Static Surveys in the USGS

25. Office of Employee Development (OED) ID1747 Application and Practice of Survey-Grade GNSS Real-Time and Static Surveys in the USGS Syllabus

26. Office of Employee Development (OED) ID1747 Application and Practice of Survey-Grade GNSS Real-Time and Static Surveys in the USGS

27. Office of Employee Development (OED) ID1747 Application and Practice of Survey-Grade GNSS Real-Time and Static Surveys in the USGS OPUS Projects

28. Office of Employee Development (OED) ID1747 Application and Practice of Survey-Grade GNSS Real-Time and Static Surveys in the USGS

29. Office of Employee Development (OED) ID1747 Application and Practice of Survey-Grade GNSS Real-Time and Static Surveys in the USGS

30. Office of Employee Development (OED) ID1747 Application and Practice of Survey-Grade GNSS Real-Time and Static Surveys in the USGS

31. PROJECT APPLICATION – Storm Surge Sensors The New Madrid Floodway Levee Breach

32. PROJECT APPLICATION – Storm Surge Sensors What’s up with Sandy…

33. Legacy Datum - Mississippi River Datum and Some Tributaries 1.Memphis Datum 2.Mean Gulf Datum 3.Fourth General Adjustment of 1912 Historic datum is considered legacy

34. Legacy Datum – Middle Mississippi River Datum – St. Louis Gaging Station Historic datum is considered legacy Middle Mississipppi River Gage Hydralic Datums Datum Conversions Zero Gage St Louis Direatrix413.68-33.74 Cario400.23-20.29 Memphis387.107.16 Mean Sea Level379.94St Louis Gage0 Mean Gulf379.800.14 Engineers Office213.68166.26

35. NAVD 88 Datum Conversion : Simple Height Conversion or Survey – “The USGS Missouri Model” Cooperative Interest Cooperative Interest Gage location hydraulics or channel instability 1. Evaluation of Source Datum Source Datum 2. Cooperative Interest Interest 3. Hydraulics and Stability and Stability 4. Accuracy assured with USACE ‘CEPD’ with USACE ‘CEPD’ and NWS modeling and NWS modeling interests interests Source Datum genesis and condition Accuracy

36. Missouri River Datum Discrepancy Example Inter-Agency Collaboration in Missouri

37. Benefits of Inter-Agency Collaboration Enhance Resources Enhance Resources Reduce Expense Reduce Expense Quality Assurance Quality Assurance Agency Consensus Agency Consensus Public Approval Public Approval

38. Continuing Inter-Agency Collaboration in Missouri  Datum Surveys – Moving Forward  USGS and USACE duplicative surveys at important gaging locations  Main stem Missouri and Mississippi River gages  Water resource operation project gages  Limited duplication at tributary gages  USGS / USACE surveys  Sharing of metadata and results  Overcome cost prohibitive gaging locations  Augmenting staff for local/regional GNSS campaigns  USGS Gaging Installation  Installation of an observable benchmark Datum Dissemination

39. Continuing Inter-Agency Collaboration in Missouri Survey assistance…. NWK SWL MVL MVS MVM USACE MODOT MDNR

40. Continuing Inter-Agency Collaboration in Missouri – FY 13 Single Base OPUS Level I Quality - SWL Augment Survey Gaging Station Number Gaging Statiion Description Observation Date Time Obsevations Used Required Amibiguities Fixed Required Solution RMS (m) Required (m) Vertical peak-to- peak (m) Required (m) Orthometric Height Average Ortho Height (m) Within 0.05m of each solution 7058000 Bryant Creek near Tecumseh, MO 10/16/20121137 - 170391%>80%94%>80%0.015<0.0300.028<0.06182.006 182.03 0.027 10/17/20120746 - 130291%>80%85%>80%0.017<0.0300.076<0.06182.0600.027 7053600 Lake Taneycomo at School of the Ozarks, MO 10/16/20121122 - 170187%>80%95%>80%0.015<0.0300.069<0.06218.965 218.97 0.003 10/17/20120725 - 120485%>80%90%>80%0.017<0.0300.027<0.06218.9710.003 7054080 Beaver Creek near Bradleyville, MO 10/16/20121123 - 170491%>80%93%>80%0.012<0.0300.028<0.06252.800 252.80 0.001 10/17/20120758 - 135890%>80%84%>80%0.013<0.0300.016<0.06252.8020.001 7053810 Bull Creek near Walnut Shade, MO 10/16/20121209 - 175396%>80%94%>80%0.012<0.0300.034<0.06229.712 229.71 0.004 10/17/20120716 - 131395%>80%87%>80%0.013<0.0300.035<0.06229.7040.004 7053820 Lake Taneycomo at School Powersite Dam, MO 10/16/20121226 - 174793%>80%95%>80%0.013<0.0300.017<0.06219.420 219.43 0.008 10/17/20120806 - 130895%>80%91%>80%0.013<0.0300.017<0.06219.4350.007 USGS Missouri Water Science Center Observations per T&M (Level I) USACE – SWL USGS - MOWSC USGS - ARWSC

41. Continuing Inter-Agency Collaboration in Missouri – FY 13

42. Inter-Agency Collaboration Datum Surveys – Assistance and Collaboration http://www.ngs.noaa.gov/ADVISORS/AdvisorsIndex.shtml

43. Inter-Agency Collaboration Mark.W.Huber@usace.army.mil Datum Surveys – Assistance and Collaboration

44. Questions? Questions ?