Patent ID: 7667826
Filing Date: 2010-02-23
Classification: G01F,G01P,G01S

Abstract:
1. A Doppler velocimeter apparatus, comprising: a coherent light source for generating a beam of coherent light; an optical fiber for receiving the beam of coherent light, the optical fiber having an output face that is generally flat, thus enabling a first portion of the beam of coherent light to be reflected back on the optical fiber and to form a frequency offset, while a second portion of the beam of coherent light exits the optical fiber; a mechanism that moves the output face of the optical fiber in an oscillating fashion, such that the first portion of coherent light reflected back on the optical fiber produces a waveform that forms a frequency offset; an optical element that receives the second portion of light from the face of the optical fiber and transmits it to a subject, and receives a reflected optical signal back at the optical element, the reflected optical signal having a frequency dependent on the motion of the subject; and a processing subsystem for mixing said first portion of the beam of coherent light and said reflected optical signal, and determining therefrom a Doppler shift of said reflected optical signal.