Basic HTML Version
ACT Protocols for Wave Measurement Systems
July 2012
2
Wave Measurement Systems Test
and Evaluation Protocols
1.0 Introduction
In 2009, the Alliance for Coastal Technologies (ACT) supported the U.S. Integrated Ocean
Observing System (IOOS), NOAA National Data Buoy Center (NDBC) and U.S. Army Corps of
Engineers (USACE) in developing community consensus on a plan for a comprehensive, high
quality surface-wave monitoring network for the United States, entitled
A National Operational
Wave Observation Plan
.
The national system of surface wave observations proposed by this
plan will increase the wave observation spatial coverage along and across the US coasts and will
serve as a stimulus for wave modeling activities in verification /validation improvements, data
fusion and assimilation. This plan (IOOS, 2009) divides the US coastline into seven primary
geographic regions and four along-coast observational sub-nets (Offshore, Outer-Shelf, Inner-
Shelf, and Coastal Subnets). The plan focuses on real-time, in situ, directional wave sensors
required to create a robust backbone across these four regions. It was further recognized by this
Plan that as waves move from offshore to the beach the observational technology changes, as
does the accuracy requirements of the sensors employed and the range of user applications.
The plan further recognizes that to serve the wide
and ever growing range of IOOS users, a national
wave observation network should accurately
resolve the directional spectra of the incident
surface gravity wave field. To achieve this goal
requires that the observations satisfy a “First-5”
standard. The plan states, “Technically, First-5
refers to 5 defining variables at a particular wave
frequency (or wave period). The first variable is
the wave energy, which is related to the wave
height, and the other four are the coefficients of
the Fourier series that define the directional
distribution of that energy.” Since both the
incident wave characteristics change with water
depth as do the preferred methods of wave
directional sensing, a clear Test and Evaluation
protocol is required to ensure that operational
wave sensing systems meet this stated goal. Technology Testing and Evaluation is called for in
the IOOS National Operational Wave Observation Plan (2009) in section 3.3. Within this
section of the report ACT is recognized as being well-positioned to support both the sensor
requirements of IOOS as well as the technology testing and evaluation component of the plan.
In this capacity, ACT hosted a Wave Sensor Technology Workshop at the University of South
Florida in March 2007 (ACT, 2007). This workshop brought together wave sensor
manufacturers and wave data users. From the workshop, the overwhelming community
consensus was that: