Accession Number : AD0163945

Title :   Instrument for Measuring the Depolarization of Backscattered Light.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Fugitt,Ronald Bruce

Report Date : 20 MAR 1973

Pagination or Media Count : 7

Abstract : The patent describes an instrument capable of obtainint information on the polarization properties of ocean waters. Operation of the instrument is as follows: Light from a He-Ne laser passes through a rotating beam chopper, a rotating linear polarizer, and a light guide and an aperture (to block spurious reflections) into the scattering medium, generally seawater. A portion of the backscattered light is intercepted by an analyzer-detector module, and after amplification the detector output is displayed on an oscilloscope. The beam is chopped at 20 times the rotational frequency of the polarizer. This provides an a-c backscatter signal which is independent of detector drift and changes in background illumination, if detector ssaturation is avoided.

Descriptors :   (*UNDERWATER LIGHTS, *PATENTS), (*UNDERWATER OBJECT LOCATORS, LIGHTING EQUIPMENT), UNDERWATER LIGHT, POLARIZATION, BACKSCATTERING, OPTICAL FILTERS, SEA WATER

Subject Categories : Air Condition, Heating, Lighting & Ventilating
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE