Narrow bandwidth detection of vibration signature using fiber lasers
| DWPI Title: System for determining vibration frequency for radar pulse reflected from target, determines frequency of vibration of vibrating target, based on Doppler-shifted frequency determined from central portion of pulse of electrical mixed signal |
| 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. |
| Use: System for determining vibration frequency for radar pulse reflected from target, such as an idling engine. |
| Advantage: At least one of the leading edge and/or the trailing edge for each received pulse can be discarded to facilitate removal of any signaling that may deleteriously affect determination of Doppler shifting of the pulse and, subsequently, determination of the vibration frequency of the pulse(s). |
| Novelty: The system (100) has a mixer (168) to mix a received optical signal with an optical reference signal to form an optical heterodyne signal. A detector (180) outputs an electrical mixed signal based on the optical heterodyne signal. An analyzer (190) extracts the central portion of a first pulse from the electrical mixed signal, and determines a Doppler-shifted frequency from the central portion of the first pulse. The analyzer determines, based on the extracted Doppler-shifted frequency, a frequency of vibration of the vibrating target. |
| Filed: 11/14/2014 |
| Application Number: US14541609A |
| Tech ID: SD 12386.0 |
| This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention. |
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