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.