Laser Slope Guage and a Spar Buoy Wave Guage: Tools for the Validation of Microwave Remote Sensors

摘要

Two devices designed to measure high frequency wave amplitude and slope are described: a spar buoy capacitance wave probe and a laser slope gauge. The spar buoy was equipped with a conventional capacitance wire probe while being tethered to a ship in coastal waters. The buoy demonstrated the capability for measuring wave height spectra at frequencies up to 2.5 Hz. The buoy hull responded weakly to the gravity wave field due to a resonant period of 7 seconds. With proper design modifications this buoy could operate independently of a tether, in deep waters, and with a frequency response up to 20 Hz. The laser slope gauge was designed to operate in water less than 1.3 m in depth. The gauge was equipped with a solid state, UDT X-Y position detector. The detector demonstrated exceptional frequency response (>1 kHz) and high spatial resolution. Wind-wave slope data obtained using this instrument reveal the ubiquitous nature of parasitic capillary waves.