SeaGuardII DCP Wave: Adaptive Tx Pulse for Wave Measurements

The presented work focuses on optimizing properties of the transmission pulse of a Doppler Current Profiler in order to reduce the measurement noise to improve acoustic directional wave detection. In addition, different methods for ambiguity correction for current and wave measurement are presented. Due to strong attenuation of short waves with increasing depth, a low noise measurement is required in order to extend the bandwidth used for wave height calculation. For ordinary current measurements, low noise gives the possibility to either reduce the variance in the measurement, or to reduce the instrument power consumption by reducing the number of pings. The presented methods consist of a combination of a wave height dependent adaptive transmission pulse combined with robust ambiguity resolution methods. These methods have been tested, validated and implemented in the SeaGuardII DCP Wave instrument in an offshore installation off the west coast of Norway.