Backscatter laser velocimeter for energetic bottom boundary layers: The optical signal

Author

Agrawal, Yogesh C. ; Terry, William E., Jr. ; Williams, Albert J., III

Author_Institution

Woods Hole Oceanographic Institution, Woods Hole, MA, USA

Volume

7

Issue

4

fYear

1982

fDate

10/1/1982 12:00:00 AM

Firstpage

150

Lastpage

154

Abstract

The optical signal from a dual-beam backscatter laser Doppler velocimeter designed for oceanographic usage will be described both theoretically and experimentally. The instrument was constructed to simulate, in the laboratory, the strength and behavior of the optical signal as a function of mass concentration of natural particles in water-a subject of concern in the study of high energy benthic boundary layers. It has been found that with proper design, the predominant mode of signal degradation with increasing particle loading is caused primarily by increased shot-noise due to signal attenuation alone. Secondly, the signal is observed to be in the single-scatterer mode at particle concentrations of up to 5 mg/l. Variations in observed signal-to-noise ratio will be described and compared with theoretical calculations.

Keywords

Laser measurements; Optical velocimeters; Sea measurements; Attenuation; Backscatter; Degradation; Instruments; Laboratories; Laser theory; Optical attenuators; Optical design; Signal design; Signal to noise ratio;

fLanguage

English

Journal_Title

Oceanic Engineering, IEEE Journal of

Publisher

ieee

ISSN

0364-9059

Type

jour

DOI

10.1109/JOE.1982.1145534

Filename

1145534