Application of Wave Drifter to marine environment observation
Mingbing Li, Suoping Zhang, Zhanhui Qi and Chaoqun Dang
National Ocean Technology Center, Tianjin, PR China.
E-mail:
limingbing@126.com
Surface following buoys are widely used to measure wave for their excellent
hydrodynamic response to wave motions. Apart from traditional wave buoys using
accelerometers as the wave sensor, recently GPS device has been an alternative for its
low cost, and many studies on wave measurement by GPS were carried out. A small
size Wave Drifter is introduced in this study as a preferred wave observing instrument
for open-sea wave-measuring applications, especially for typhoon wave. The Wave
Drifter, which is based on a single GPS receiver, uses measurements of Doppler shift
in GPS signals to derive wave parameters and transmits the results via BEIDOU
satellites hourly. In this study, laboratory experiments were designed to simulate
perfect harmonic wave motion by a dynamic simulator, in order to verify the accuracy
of wave-processing algorithm. Several field tests in coastal area were carried out.
Intercomparison between the derived wave parameters including direction properties
and the Waverider's measurements showed good agreements. A Wave Drifter was
launched around east of Taiwan in the West Pacific area from a R/V ship in late
October 2013. Wave conditions during Typhoon KROSA (2013 29) were recorded
and the maximum of significant wave height of 5.8 meters was detected where the
buoy was located around 256km to KROSA. The Wave Drifter provides a
cost-effective way to wave measurements, and many applications will benefit from
this technology, such as data assimilation and validation of wave forecast models,
calibration of satellite wave sensors and investigation of ocean wave climate and
variability.