History of GPS Buoy Development at the Universtiy of Colorado

The University of Colorado pioneered and has been involved with the application of ocean buoys equipped with Global Positioning System (GPS) receivers since 1990. This paper will discuss recent applications of GPS buoys to oceanographic and remote sensing problems. These include altimeter calibration/validation, measurement of mean sea level, and use of a GPS buoy for positioning subsurface acoustic probes for current measurement. We have conducted several ocean buoy experiments off the California coast adjacent to platform Harvest in order to calibrate the altimeter range bias associated with the TOPEX/Poseidon altimeter. In collaboration with the French Space Agency, CNES, we have performed GPS buoy surveys of mean sea level (which closely approximates the marine geoid) in the vicinity of Corsica in the Mediterranean Sea. This area has been designated as a calibration site for the Jason-1 altimetric mission scheduled for launch in May, 2000. In the fall of 1999 we plan a GPS buoy experiment in the vicinity of platform Harvest to calibrate the range bias associated with the Geosat Follow-On altimeter. In addition to measuring sea level directly under the altimeter track, these calibration experiments involve the use of GPS buoys to map mean sea level in the vicinity of Platform Harvest. Sea level accuracy from this experiment is of the order of a centimeter. GPS buoys were also used in experiments with the University of Miami to position under water acoustic probes for use in profiling currents with depth.