ON THE MEASUREMENT OF DIRECTIONAL WAVE SPECTRA BY THE NEW WAVE MEASURING SYSTEM USING LASER BEAMS

The wave measuring system applying laser beams for wave surface probes was recently developed by Experimental Tank of Yokohama National University. Laser spot projectors are set as the wave probe array under water and He-Ne laser beams are projected vertically upward from each projectors. Images of laser spots on the wave surface are taken by a video camera. The digital information of wave heights or wave slopes are obtained from processed video signals. These measured timeseries are converted to the wave time histories of multi positions by a personal computer in real time. The directional wave spectrum is estimated by the Maximum Likelihood Method. Moreover, the hard copies of 3-D graphs of directional spectra are processed immediately. In the paper principles of these new measuring systems and related numerical calculus are mentioned and the measured examples are shown. These new systems showed excellent abilities and performance.

• Supplemental Notes:
  • J. Soc. Naval Architects Japan 166 (1989) p.173 (Dec.) [14 p., 6 ref., 21 fig., 3 phot.]
• Authors:
  • Takezawa, S
  • Takayama, Tomotsuka
• Publication Date: 1989

Language

• Japanese

Subject/Index Terms

• TRT Terms: Electromagnetic spectrum; Measurement; Test facilities
• Old TRIS Terms: Directional waves; Wave generators
• Subject Areas: Marine Transportation; Terminals and Facilities;

Filing Info

• Accession Number: 00697491
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Aug 14 1995 12:00AM