Patent ID: 11906350
Assignee: GOVERNMENT OF THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF THE AIR FORCE
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 8:
9. A process for calibrating a laser Doppler vibrometer, the process comprising:
receiving, by a bidirectional frequency shifter stage, primary laser light from a laser Doppler vibrometer, the primary laser light comprising a primary frequency and that is propagating in a forward propagation direction to the bidirectional frequency shifter stage from the laser Doppler vibrometer;
producing, by the bidirectional frequency shifter stage from the primary laser light, frequency shifted light comprising a shifted frequency, such that the shifted frequency differs from the primary frequency;
communicating, in a forward propagation direction, the frequency shifted light from the bidirectional frequency shifter stage to a reflector;
receiving, by the reflector, the frequency shifted light that propagates from the bidirectional frequency shifter stage to the reflector in the forward propagation direction;
reflecting, by the reflector, the frequency shifted light back to the bidirectional frequency shifter stage in the reverse propagation direction;
receiving, by the bidirectional frequency shifter stage, the frequency shifted light reflected by the reflector that propagates from the reflector to the bidirectional frequency shifter stage in the reverse propagation direction;
producing, by the bidirectional frequency shifter stage, secondary light comprising a secondary shifted frequency from the frequency shifted light reflected by the reflector, such that secondary shifted frequency differs from the shifted frequency and from the primary frequency;
communicating, the secondary light from the bidirectional frequency shifter stage, to the laser Doppler vibrometer in the reverse propagation direction, such that the laser Doppler vibrometer receives the secondary light from the bidirectional frequency shifter stage and produces a synthetic velocity shift from the secondary light;
receiving the synthetic velocity shift from the laser Doppler vibrometer by an analyzer in electronic communication with the laser Doppler vibrometer; and
determining, by the analyzer, a calibration of the laser Doppler vibrometer from the synthetic velocity shift.