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 & VENTILATION
      OPTICS


Distribution Statement : APPROVED FOR PUBLIC RELEASE