Offshore Vertical Datum Separations Derived from Post-Processed Kinematic (PPK) Heights Observed Along a Scheduled Ferry Route

TitleOffshore Vertical Datum Separations Derived from Post-Processed Kinematic (PPK) Heights Observed Along a Scheduled Ferry Route
Publication TypeThesis
Year2008
AuthorsWardwell, NC
Degree and ProgramMaster of Science
DegreeEarth Sciences/Ocean Mapping
Number of Pages133
Date Published12/2008
UniversityUniversity of New Hampshire
LocationDurham, NH
Keywordspost-processed kinematic heights, ppk, vertical datum

Eight months of GPS data were used to determine tidal constituents along a ferry route across the Bay of Fundy, Canada. The GPS data were aggregated into 62 spatial zones and analyzed as if all the data within each zone were from a single Virtual Tide Gauge (VTG). Tidal models were developed from the VTG data using a weighted least-squares solution. Chart Datum with respect to the ITRF2000 was computed for each spatial zone using 8 months of predicted water-levels.

The time between ferry crossings results in sampling intervals longer than the tide signal in the Bay of Fundy, thus traditional methods of harmonic analysis are not applicable. Instead, a priori knowledge of the tide signal at each end of the ferry route is used to overcome the large and non-uniform sampling intervals. The results were confirmed by a close match between Mean Seal Level and the local Geoid.