An observation technique and GPS buoy processing strategy for ocean surface monitoring

This paper presents a kinematic positioning approach that uses a Global Positioning System (GPS) buoy for precise ocean surface monitoring. A field test was conducted to validate the observation technique and the processing strategy applied in this study; observation was performed at three stations located at different distances from the control station. Then, the observation technique was applied during the field observation off the Senggarang Coast. The GPS buoy data obtained from this observation were processed through a precise, medium-range differential kinematic technique. These data were collected over a period of more than 24 hours from a nearby coastal site at a high rate (1 Hz), along with the measurements from neighboring tidal stations to verify the estimated sea surface heights. The kinematic coordinates of the GPS buoy were estimated via epoch-wise pre-elimination and the backward substitution algorithm. Test results show that centimeter-level accuracy in sea surface height determination can successfully be achieved with the proposed technique. The centimeter-level agreement between the two methods also suggests the possibility of enhancing (or even replacing) current tidal gauge stations with this inexpensive and more flexible GPS buoy equipment.