Performance Characteristics of “Spotter,” a Newly Developed Real-Time Wave Measurement Buoy

• Published in: Journal of atmospheric and oceanic technology 2019-06, Vol.36 (6), p.1127-1141
• Main Authors: Raghukumar, Kaustubha, Chang, Grace, Spada, Frank, Jones, Craig, Janssen, Tim, Gans, Andrew
• Format: Article
• Language: English
• Subjects: Alternative energy; Application programming interface; Buoy measurements; Buoy observations; Buoys; cean; Confidence; Energy industry; Engineering; ENVIRONMENTAL SCIENCES; Field study; Form factors; Global positioning systems; Global positioning systems (GPS); GPS; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Kinematics; Laboratories; Linear waves; Low cost; Measurement; Meteorology & Atmospheric Sciences; Ocean waves; Parameters; Propagation; Random waves; Real time; Renewable energy; Satellite communications; Significant wave height; Solar energy; Statistical analysis; Surface observations; Time measurement; Wave direction; Wave height; Wave measurement; Wave power; Wave spectra; Wind waves
• ISSN: 0739-0572; 1520-0426
• DOI: 10.1175/JTECH-D-18-0151.1

The Spotter is a low-cost, real-time, solar-powered wave measurement buoy that was recently developed by Spoondrift Technologies, Inc. (Spoondrift). To evaluate the data quality of the Spotter device, we performed a series of validation experiments that included comparisons between Spotter-derived motions and prescribed wave motions (monochromatic and random waves) on a custom-built, motion-controlled validation stand and simultaneous in-water measurements using a conventional wave measurement buoy, the Datawell DWR-G4 (Datawell). Spotter evaluations included time-domain validation (i.e., wave by wave) and comparisons of wave spectra, directional moments, and bulk statistical parameters such as significant wave height, peak period, mean wave direction, and directional spread. Spotter wave measurements show excellent fidelity and lend a high degree of confidence in data quality. Overall, Spotter-derived bulk statistical parameters were within 10% of respective Datawell-derived quantities. The Spotter’s low cost and compact form factor enabled unique field deployments of multiple wave measurement buoys for direct measurements of wave characteristics such as ocean wave decorrelation length scales, wave speed, and directional spread. Wave decorrelation lengths were found to be inversely proportional to the width of the spectrum, and wave speeds compared well against linear wave theory.