1. Naval Oceanographic Office Charting Products Division (N43) Naval Oceanographic Office Hydrography Department upgrades to its Positioning Systems and Hopes to Operationally reduce its bathymetric measurements to a seamless vertical datum by Elliot N. Arroyo-Suarez, N43P

2. Naval Oceanographic Office Charting Products Division (N43) Requirements Capabilities As-Is Recent Developments Possible Implementations Questions/Discussions

3. Naval Oceanographic Office Charting Products Division (N43) IHO’s 3-D Accuracy - Requirements Geodetic Horizontal Control – 10cm 95%

4. IHO Depth Total Propagated Error (TPE)

5. Naval Oceanographic Office Charting Products Division (N43) Processing Capabilities As-Is

6. Naval Oceanographic Office Positioning As-Is Require Force Protection Plan Geodetic Survey Deploy an Advance 4 –5 personnel Survey Party Perform Geodetic Survey Forward Observation to NGA NGA Process and Produce a Geodetic Solution NAVO Produce a Geodetic report from NGA Report

7. NGA Primary Position Reported at 10cm CEP Secondary Positions post-processed after primary position is acquired with Trimble Geomantic Office (TGO) Can take several weeks to obtain positions in support of Hydrographic Surveys Naval Oceanographic Office Positioning As-Is

8. Naval Oceanographic Office Charting Products Division (N43) New Processing Capabilities NAVOCEANO Positioning System NAVPOSS

9. Naval Oceanographic Office Positioning - New Initiatives

10. Naval Oceanographic Office Positioning - New Initiatives 3D Positions relative to Ground Stations & Sat Orbits Long baseline solution - Iono-Free LC or L3 resolve phase ambiguities using both ionospheric constraint and pseudorange data. Triple Difference to edit data when cycle slips are present. Directly use L1 and/or L2 phase over short baselines (Iono negligible) QC of GPS Data In-Situ; Immediately after observations Position Adjusted to 11 IGS prime fiducials

11. Naval Oceanographic Office Positioning - New Initiatives Report and Geodetic Positions Generated soon after CORS RINEX files become available. Every 24/hrs. Online SOP enables each Hydrographic crew to perform Geodetic Surveys Geodetic Surveys automatically save on MySQL database Expect Centimeter Level (Wide Lane) Accuracy Anywhere

12. Naval Oceanographic Office Positioning - New Initiatives

13. Naval Oceanographic Office Charting Products Division (N43) As-Is NAVOCEANO Navigation As-Is

14. Naval Oceanographic Office Navigation As-Is Measurement-Space WADGPS Range corrections Position error estimation dependent on users location relative to the reference network NAVOCEANO Observations – Equatorial Region ~14m Horizontal 95% – 1000 Km baseline NAVOCEANO Observations – Ascension >15m Vertical 95%

15. Naval Oceanographic Office New Technology NAVOCEANO Navigation New GPS System Initial Results

16. Naval Oceanographic Office Navigation - New Technology RTG State-Space Orbits precisely modeled producing precise satellite States and Clocks Real Estimation of satellite physical parameters Guarantee global uniformity and validity

17. Naval Oceanographic Office New Technology DGPS, WAAS, EGNOS, RTK & Commercial Implementation of Real Time GIPSY (RTG) Initial Results

18. Naval Oceanographic Office Navigation Positioning – Newer RTK Rover/Base System

19. Naval Oceanographic Office Navigation Positioning – New RTK Base/Rover System 2 x KC60 Arrays, COTS Rack, & Custom Electronics Enclosure 900MHz Antenna Data Link FreeWave Transmitter Enclosure 12 Meters Power Generation Enclosure NOT TO SCALE Tri-Band Antenna GFE Tripod

20. Naval Oceanographic Office Navigation Positioning – Estimated UHF Radio Range

21. Naval Oceanographic Office Navigation - New Technology RTG Evaluation Results NAVO, SSC, 2003 Earth Tide NOT Applied Ascension Island, 2002

22. Naval Oceanographic Office Navigation Positioning – Newer Technology RTG/RTK System NCT ZBL RTK Accuracy 95% H = 0.01m V = 0.018m Dynamic RTG Vertical Accuracy 95% RTK – RTG Fixes = 0.54m Earth Tide Corrector NOT Applied

23. Naval Oceanographic Office Charting Products Division (N43) NAVPOSS (GAMIT) Solid Earth Tide Correctors

24. Naval Oceanographic Office NAVPOSS Earth Tide Correctors

25. Naval Oceanographic Office NAVPOSS Earth Tide Correctors

26. Naval Oceanographic Office NAVPOSS Earth Tide Correctors V.A.= 0.43 95%V.A.= 0.24 95% RTG Static Solution – NAVO SIL

27. Naval Oceanographic Office NAVPOSS Earth Tide Correctors What if we fit a Polynomial to the Tide Corrected RTG Height Solution ? Tide Correction 44% Accuracy Improvements Polynomial Fit 58% Accuracy “Improvement” V.A.= 0.099 @ 95%

28. Naval Oceanographic Office Charting Products Division (N43) Applications of NAVO RTG/RTK System From the Sea Initial Proposal

29. Naval Oceanographic Office Charting Products Division (N43) Typical Continental Shelf Multi-Year Hydro Survey Outside 12nm Territorial Limits – No Access to Land

30. Depth Corrector due to Water Level Variation (Tides) – Off Shore RTK/RTG Vessel, Vertical Datum Not Available Echo Sounder Measurement Charted Depth Ellipsoid to Chart Datum Distance --3 - -- 2 - -- 1 - -- 0 MHHW MHW MTL DTL MSL MLW MLLW WGS84 Ellipsoid (2) GPS Buoy RTG/RTK Measure Ellipsoidal Ht. to Waterline Static Draft 3 Alternatives (1) Bottom Mount Tide Gauge GPS Buoy Determine Water Levels Referenced to the Ellipsoid Bottom Mount Tide Gauge. Distance from Seabed to Ellipsoid Determined by RTK/RTG Equipped Vessel (3) Vessel Record Ellipsoidal Height Time Series, to determine Chart Datum & Water Levels

31. Naval Oceanographic Office Charting Products Division (N43) Typical Continental Shelf Multi-Year Hydro Survey Outside 12nm Territorial Limits – No Access to Land

32. Naval Oceanographic Office Charting Products Division (N43) Rob Hare’s Error Model Assuming.27m RMS on GPS-Z and Chart Datum @15m depth

33. Naval Oceanographic Office Charting Products Division (N43) Rob Hare’s Error Model Assuming.13m RMS on GPS-Z and Chart Datum @15m depth

34. Naval Oceanographic Office Charting Products Division (N43) To Do: Implement Solid Earth Tide Corrector to RTG Navigation Implement an optimum filtering technique to: Smooth GPS-Z data to derive Chart Datum Smooth GPS-Z data to reduce soundings to chart dtaum from RTG/RTK GPS-Z data Long Term Field Tests (~month) Bottom Mounted Gauge RTG-Z Chart Datum and Water Level Corrector RTG/RTK-Z Buoy ??? Generate X-Checks statistics from GPS-Z corrected depths

35. Naval Oceanographic Office Charting Products Division (N43) Questions/Discussion