Acquisition & Processing

1. Acquisition & Processing • Fledermaus / CUBE • Shoreline • Quality Control • PPK Analysis • Tides • NRTK • Multibeam Processing

2. PPK Analysis

3. PPK Analysis • RMS of GPS heights

4. PPK Analysis • Local Storm Events

5. DOP PPK Analysis • H-RMS vs PDOP No storm event, but still a ‘jump’? NDBC did not experience a similar ‘jump’… perhaps an equipment problem?

6. PPK Analysis • Ashtech comparison • Simultaneous static observation Static field test suggestive of an equipment failure…

7. PPK Analysis

8. PPK Analysis STORM FRONT ADVANCING

9. PPK Analysis RAIN ALL DAY

10. PPK Analysis STORM

11. PPK Analysis

12. PPK Analysis Conclusions… • Poor weather is a precursor to poor PPK (at rover or base) • Good weather is not a sufficient condition for good PPK • Difficult to correlate predicted PDOP spikes with poor PPK • The equipment may be faulty…PE worthy?

13. Tides North Quay Wall South Quay Wall

14. Tides • Vertical Datum established through static GPS observations at Bench Marks • Sounding Datum then determined by using recovered relationship (From class of 05) between NAVD 88 and local SD • Further analysis conducted using T-Tide to determine constituents

15. Leveling 0.699

16. Sounding Datum • Sounding Datum transfer (Diurnal tides) • Previous Transfer conducted by class of 05

17. Sounding Datum • As a check to this, a Diurnal SD transfer was conducted using constituents Height of CD above zero of new gauge Height of MSL above zero of new gauge Sum of M2,S2,K1 & O1 at new gauge d = z’ – (Z’ x h/H) Height of MSL above CD of established gauge Sum of M2,S2,K1 & O1 at established gauge

18. Comparison 2005 Transfer: 0.699m 2008 Transfer: 0.849m Why? * Difference in constituents analysed using t_tide * Length of observations on new gauge * Same method used in 05?

19. Tidal Analysis

20. Tidal Analysis

21. Tidal Analysis K1: Diurnal Moon O1: Diurnal Moon

22. Tidal Analysis Short Frequency Constituents

23. NRTK • The Gulf Coast Geospatial Center loaned us a Trimble R7 with TSC2 controller • This piece of equipment was deemed useless for our purposes because: • It doesn’t work at typical survey speeds • It doesn’t time stamp the data it collects • It has no cell phone connectivity in our survey area Frisbee anyone?

24. 2 m Static Tide Obs

25. Fledermaus / CUBE

26. The Big Picture Bathymetry Data Tide Data PPK GPS Sound Velocity True Heave CARIS HIPS IVS Fledermaus Filtered Soundings CUBE Surface

27. Multibeam Processing Software CARIS HIPS 1 Convert XTF to HDCS Apply correctors and filters CUBE surface IVS Fledermaus Create PFM Flag data using CUBE hypothesis Filter data to CUBE surface • FLEDERMAUS PARAMETERS: • Filter: 1.5 σ of CUBE surface • Noisy data • Confident in CUBE surface CARIS HIPS 2 Quality Control & final cleaning Recompute CUBE surfaces Finalize CUBE surfaces QINSy Export QINSy (.db) to XTF • CUBE PARAMETERS: • IHO Order 1 (area of influence of sounding to node) • Disambiguation Method: Density and Locale (hypothesis with greatest number of soundings consistent to neighboring nodes) • Configuration: Default (Surface creation/disambiguation)

28. Key CUBE Assumptions • Assuming all gross errors have been removed: • The more soundings CUBE has, the more robust and certain the solution. • The larger the area processed, the more efficient the validation.

29. Ideal Situation

30. What we had

32. Processing Facts • 451,956 CUBE bins • With 1m Bins: 451,956 m2 • Checked Areas: 105,042 m2 – 23% Checked • 45,070 Edited CUBE bins – 10% Changed • 38,399,520 Total Soundings • 30,008,414 Accepted Soundings • 8,391,106 Rejected Soundings – 22% Rejected • CUBE Validation Time: 18hrs • Dot Killing at 10 dots a second – 233hrs

33. Shoreline • Preparation • Aerial Photographs • Mississippi Geospatial Clearinghouse • February 14, 2007 • Scale: 1 to 100 • 15 cm ground sample distance • Orthorectified to the Mississippi State Plane Coordinate System • Datum: NAD 83 and NAVD 88 • CARIS Notebook • COALNE • 1:3,000

34. Shoreline • Acquisition • Shoreline files converted from .hob to .000 • Loaded in to HYPACK and QINsy as background files • Shoreline visually verified during SBES, SSS, and MBES acquisition • Processing • S-57 Composer • MBES Soundings • Results • Priority Areas 1 & 2 • ~10 meters inshore the digital imagery

35. Shoreline ~10 m Original Coastline Updated Coastline

36. ATONs • GPS • Trimble (DGPS) • GARMIN GPSMAP 76 • CARIS Notebook • GPS Logging • Real time S-57 attributes • .hob file to S-57 Composer for ENC compilation

37. ENC New Detached Position

38. ENC GARMIN 76 Trimble ATONs

39. Quality Control • TPU • Crossline Check • Chart Comparison • Singlebeam vs. Multibeam • Prior Surveys

40. Quality Control - TPU Reasonable TPU values??? TPU (m) An increase in TPU was noted with increasing beam angle …

41. Quality Control - TPU TPU (m) …while a minimum in TPU was noted at the nadir angle.

42. Quality Control - TPU TPU (m) An odd ‘plateau’ was noted in the starboard-most beams’ TPU…

43. Quality Control - TPU Noisy outerbeams resulting from a truncated receive time… …where outer-fluff is at a constant range…

44. (m) Slant Range (m) Quality Control - TPU …Total Fluff meets IHO Order 1a specs?!? TPU …which prompted us to compare TPU to Slant Range

45. Quality Control – Crossline Check Two crossline comparisons were performed • Intraday – Comparing morning and afternoon datasets • Interday – Comparing datasets from Dn182 and Dn183

46. ~100 Quality Control – Crossline Check Intraday… Beam #

47. ? ~100 Quality Control – Crossline Check Interday… Beam #

48. ~100 off center beam Quality Control – Crossline Check

49. ~100 Quality Control – Crossline Check

50. Quality Control – Crossline Check