| Abstract: | The various technologies presented herein relate to extracting a portion
of each pulse in a series of pulses reflected from a target to facilitate
determination of a Doppler-shifted frequency for each pulse and,
subsequently, a vibration frequency for the series of pulses. Each pulse
can have a square-wave configuration, whereby each pulse can be
time-gated to facilitate discarding the leading edge and the trailing
edge (and associated non-linear effects) of each pulse and accordingly,
capture of the central portion of the pulse from which the
Doppler-shifted frequency, and ultimately, the vibration frequency of the
target can be determined. Determination of the vibration velocity
facilitates identification of the target being in a state of motion. The
plurality of pulses can be formed from a laser beam (e.g., a continuous
wave), the laser beam having a narrow bandwidth. |