GPS tides: A project to determine todal datums with the Global Positioning System

dc.contributor.authorDeLoach, Stephen, R.
dc.description.abstractThe recent development of on-the-fly ambiguity resoltuion techniques with Global Positioning System (GPS) observations has created a powerful tool for the study of dynamic time series, such as tidal analysis or the study of water level heights. For this project a GPS receiver was successfully operated on board a Canadian Coast Guard navigation buoy. Ten days of data, at a one-second sample interval, were collected at a station in the open waters of the Bay of Fundy, followed by ten days from an inshore mooring. The buoy data were transmitted in real time to a reference station on shore where antenna heights were computed in real time. Subsequent processing reduced the 1-Hz antenna height series to a 15-minute water surface height series for comparison to two nearby "conventional" gauges. These were the Saint John Harbour permanent gauge and a temporary Socomar pressure gauge. Mean tide heights computed from the inshore data are all within 1 centimetre. The means, computed from the inshore series, differed by 10 centimeters between the buoy and the "conventional gauges," indicating a differential slope between the water surface and the ellipsoid. In addition to the water surface measurements, about 10 days of GPS data were collected from a static baseline to characterize the performance of the on-the-fly GPS system, without the influence of a moving platform. From the 20 days of data, 97 percent is within 3 cm of truth, while the mean daily heights are about 0.3 cm below the truth. This project has demonstrated that the "GPS buoy" is a viable method od tidal datum determination and it should be possible to use the ellipsoid as the basis for water surface datums.
dc.description.copyrightAs with any copyrighted material, permission to reprint or quote extensively from this report must be received from the author.
dc.subject.disciplineGeodesy & Geomatics
dc.titleGPS tides: A project to determine todal datums with the Global Positioning System
dc.typetechnical report
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
8.41 MB
Adobe Portable Document Format