A non-contact method is presented for measuring vibration on a surface of an object. The method includes: projecting light from three light sources towards a point of interest on a surface of an object, and detecting the light reflected by the point of interest on the surface using three detectors, where each detector of the three detectors captures light from a corresponding one of the three light sources. From the light captured, calculating vertical displacement of the surface at the point of interest using triangulation, calculating rotational displacement of the surface at the point of interest about an x axis using triangulation; and calculating rotational displacement of the surface at the point of interest about y axis using triangulation, where the x axis and the y axis define a plane which is parallel to surface of the object.

A distributed fiber optic acoustic detection device employs a novel distributed acoustic detection method using a phase noise cancelling distributed acoustic sensing (PNC-DAS) technique.

In a pilotless flying object detection system, a masking area setter sets a masking area to be excluded from detection of a pilotless flying object which appears in a captured image of a monitoring area, based on audio collected by a microphone array. An object detector detects the pilotless flying object based on the audio collected by the microphone array and the masking area set by the masking area setter. An output controller superimpose sound source visual information, which indicates the volume of a sound at a sound source position, at the sound source position of the pilotless flying object in the captured image and displays the result on a first monitor in a case where the pilotless flying object is detected in an area other than the masking area.

A calibration apparatus for calibrating a laser Doppler vibrometer includes: a frequency shifter stage that: receives, from the laser Doppler vibrometer, primary laser light; produces frequency shifted light; communicates the frequency shifted light to a reflector; receives frequency shifted light reflected by the reflector; produces secondary light; and communicates the secondary light to the laser Doppler vibrometer, such that the laser Doppler vibrometer receives the secondary light from the frequency shifter stage and produces a synthetic velocity shift from the secondary light; and the reflector that receives and reflects the frequency shifted light back to the frequency shifter stage.

A method for detecting blowout precursors in at least one gas turbine combustor comprising: receiving combustion dynamics acoustic data measured by an acoustic measuring device associated with the combustor in real time; performing wavelet analysis on the acoustic data using simplified Mexican Hat wavelet transform analysis; and determining the existence of a blowout precursor based at least in part on the wavelet analysis. Provided also is a system and a non-transitory computer readable medium configured to perform the method.

The present disclosure generally relates to systems and methods for imaging and sensing vibrations of an object. In one implementation, a system is provided for detecting vibrations that comprises a sensor with a plurality of pixels, each pixel including at least one photosensitive element. The sensor is configured to output signals related to illumination on each pixel. The system also includes at least one processor configured to receive the output signals from the sensor and detect, based on the output signals, one or more polarities. The at least one processor is also configured to determine timestamps associated with the output signals, analyze the timestamps and the polarities to detect vibrations of an object in the field of view of the sensor, and determine one or more frequencies of the detected vibrations.

Systems and methods are provided for vibrations detection in a scene. Systems comprise at least one coherent light source configured to illuminate the scene, an optical unit configured to focus scattered light from the scene onto a pixelated detector, the detector configured to provide pixel intensity signals, and a processing unit configured to analyze the pixel intensity signals over the pixels of the detector to derive a vibration spectrum of elements in the scene that correspond to the pixels. The signal modulation at each pixel may be used to indicate the vibrations of the scene element(s) that corresponds to the pixel(s). Vibration information concerning the scene may be used to direct other methods of vibration measurements, such as speckle interferometry, according to derived vibration images of the scene.

The present invention relates to a full-field vibration measurement method based on microwave sensing, which is characterized by comprising the following steps: step 1, repeatedly transmitting linear frequency modulated continuous wave microwave signals by means of one or more transmitting antennas; step 2, receiving reflected signals from targets and/or measurement points by means of a plurality of receiving antennas, and performing frequency mixing on received signals and local oscillator signals to obtain multi-channel intermediate frequency baseband signals; step 3, acquiring intermediate frequency baseband signals in various channels, and resolving and positioning targets and/or measurement points within the full field based on a joint range and angle dimension; and step 4, extracting vibration displacement time-domain information of targets to be measured and/or measurement points. By means of the full-field vibration measurement method based on microwave sensing provided in the present invention, synchronous vibration information measurement of targets and/or measurement points within the full field is achieved by positioning and resolving the targets and/or measurement points within the full field based on a joint range-angle dimension and tracking phase evolution, thereby solving the difficulties in the prior art that full-field vibration measurement and interference suppression cannot be achieved.

Systems and methods for improving spectral-shift methods for calculating acoustic attenuation coefficients are disclosed. Systems, methods, and apparatuses for transmitting ultrasound pulse sequences for improved signal-to-noise outside the main passband of ultrasound transducers are disclosed. Systems, methods, and apparatuses for using the echoes from the transmitted pulse sequences to calculate the attenuation coefficient are disclosed.

A system is provided for actively mitigating noise caused by vibration of a thin vehicle front windshield in an occupant compartment of a vehicle. The system includes a pair of laser scanners configured to be mountable inside the vehicle occupant compartment. Each laser scanner is configurable to scan an associated initial portion of the windshield simultaneously with the other laser scanner, when the windshield is vibrating.