System and method for measuring velocity using frequency modulation of laser output

Abstract

A system for measuring velocity of a target is disclosed. In one embodiment, the system includes a laser device, a detector and a signal processor. The laser device produces a frequency-modulated laser beam, wherein the frequency-modulated beam is split into at least two laser beams, wherein a reflected beam comprising one split beam is directed to the target and reflected from the target. The detector detects a combination of the reflected beam and a reference beam comprising another split beam, wherein the reflected beam and the reference beam have unequal delays. The signal processor obtains velocity information from the combined beam by use of Doppler-shifted harmonies of the modulation frequency.

1 . A method of measuring velocity, comprising: 
 generating a frequency-modulated laser signal, the frequency-modulated signal being directed to a target; and    measuring the velocity of the target based on a combination of the frequency-modulated laser signal and a reflected signal from the target.