Basic HTML Version
ACT Protocols for Wave Measurement Systems
July 2012
20
East Coast deployment site is also capable of capturing episodic events in the form of tropical
cyclones or severe winter storms.
An additional component of an Eastern Gulf of Mexico evaluation would include co-locating
wave sensing technologies with the CODAR and WERA footprint. There is an operational
WERA system located on the West coast of Florida between Coquina Beach and Venice. There
are also three CODAR sites in this region at Redington Shores, Venice, and Naples. The
evaluation of the radar technology may include the First-5 in limited situations. There is interest
in comparing wave statistics from the Waverider to those generated by the radar, particularly for
large amplitude, episodic events.
10.5 Test Instrument Calibration and Deployment
At all test and evaluation deployment sites described above, both the reference and the test
systems should be co-located to the extent feasible. It should be assured that there is substantial
distance between the test site and hydrographic features that may cause spatial variation in the
wave field. The system separation distances will be dictated by the water depth and mooring
lengths. The instrumentation should be as close as possible without interference from one
another and each test system should be deployed equal distance from the reference buoy.
10.6 Ancillary Measurements
ACT will provide measurements of local meteorological data as well as and in-water ancillary
data (water velocity and temperature). Both deep and shallow water sites have existing
infrastructure and monitoring for these variables. However, ACT will guarantee their
availability and performance to participating manufacturers and the NWS WFO.
10.7 Reference Instrument Calibration and Deployment
10.7.1 Datawell Waverider
The calibration of the Waverider is essentially the comparison of measurements performed in the
ferris wheel (the rig) to the known dimensions and orientation of the rig, at three different
frequencies (corresponding to 20, 12.5 and 6.25 s). The rig’s orientation is regularly established
by a reference compass. In addition, the cross-sensitivity of the accelerometers is checked, as
well as the (sea surface) temperature sensor. (For details on the calibration process, see
http://download.datawell.nl/documentation/datawell_publication_hydrographicinstrumentation-
calibrationwavebuoys_oct1993_2004-06-30.pdf)
Instrument Standard is a Datawell Mark III Series Directional Waverider. For details
concerning the Datawell Mark III deployment and operations, please consult the Datawell DWR-
MKIII manual accessible on the website at: http://datawell.nl. The pre-deployment buoy
configuration and preparation should be verified according to the Datawell DWR manual.
Between each deployment, accelerometer and compass checks are performed. Datawell suggests
that every 3-6 years, the buoy is returned for calibration. Calibration ferris wheels are presently
located in The Netherlands at the Datawell facility or at CDIP at the Scripps Institution of