Waves from cement bond logging with a sonic logging-while-drilling tool (LWD-CBL) are often contaminated with tool waves and may yield biased CBL amplitudes. The disclosed LWD-CBL wave processing corrects the first echo amplitudes of LWD-CBL before calculating the BI. The LWD-CBL wave processing calculates a tool wave amplitude and a phase angle difference as the difference of the phases between the tool waves and casing waves. The tool waves are then used to correct the LWD-CBL casing wave amplitude and remove errors introduced from tool waves. In conjunction with the sets of operations described, the LWD-CBL wave processing also include array preprocessing operations. Array preprocessing may employ variation of bandpass filtering and frequency-wavenumber (F-K) filtering operations to suppress tool wave.

According to one embodiment, an inspection apparatus includes a vibration sensor, a microphone, and a processor. The vibration sensor detects a vibration of an inspection target object to which the vibration is excited. The microphone arranged near the inspection target object and collects a radiated sound from the inspection target object. The processor calculates an impulse response between the vibration sensor and the microphone. The processor denoises an unnecessary component from the impulse response. The processor converts the impulse response into a frequency characteristic. The processor calculates acoustic energy between the vibration sensor and the microphone based on the frequency characteristic. The processor determine the presence/absence of an abnormal state of the inspection target object.

A method and system for inspecting a rail by guided waves, the rail being instrumented by sensors. The method comprises the steps of receiving elastic wave measurements from one or more sensors, as a train passes, releasing energy as guided waves into the rail; and of determining a function representative of the impulse response of the rail and the sensors. Developments describe how to determine the existence, position and characterisation of a defect in the rail (e.g. fracture, incipient fracture, etc.), the use of inter-correlation analyses, correlation of the coda of correlations, Passive Inverse Filter, imaging techniques. Other aspects are described for exploring rail defects: sensor position and movement, acquisition time, sampling frequency, frequency filters, amplifications, techniques for learning during successive train passes, signal injection by transducers. Software aspects are described.

Embodiments of the invention include a system and method for detecting wood-boring species of insects in a structure (16), involving one or more primary (14) and reference (18) sensors and a signal conditioning and acquisition device (22) capable of being coupled to the sensors (14, 18). The system (10) also includes a processor (24) capable of being coupled to a non-transitory, computer-readable storage medium that includes program logic for execution by the processor (24). The program logic includes a logic module that receives signals originating from the sensors (14, 18) and discriminates between noise generated by any wood boring species in the structure and extraneous noise unrelated to the wood boring species of insects. The extraction of signal features based on pulse duration, signal spectra and signal envelope spectra can be used for insect pulse discrimination. A sound-suppressing sensor assembly (12) can be weighted to enhance the coupling of the primary sensor (14) with the structure (16) being tested.

In example embodiments, an apparatus includes a microphone, an emitter follower stage having an input coupled to the microphone, and an amplifier stage coupled to an output of the emitter follower stage. The amplifier stage is powered by a positive voltage regulator and a negative voltage regulator. In some embodiments, the microphone and the emitter follower stage are both referenced to a ground connection and are both biased by the positive voltage regulator. The output of the emitter follower stage may have an impedance that is an order of magnitude less than an impedance of the microphone. In some embodiments, the apparatus may be used to detect ultrasonic signals, such as those emitted by animals such as bats, rodents, and pest insects.

Method for ultrasonic characterization of a medium, comprising generating a series of incident ultrasonic waves, generating an experimental reflection matrix R.sub.ui(t) defined between the emission basis (i) as input and a reception basis (u) as output, and determining a focused reflection matrix RFoc(r.sub.in, r.sub.out, δt) of the medium between an input virtual transducer (TV.sub.in) calculated based on a focusing as input to the experimental reflection matrix and an output virtual transducer (TV.sub.out) calculated based on a focusing as output from the experimental reflection matrix, the responses of the output virtual transducer (TV.sub.out) being obtained at a time instant that is shifted by an additional delay δt relative to a time instant of the responses of the input virtual transducer (TV.sub.in).

The present disclosure is generally directed to an ultrasonic transducer interface system for use within portable 2-D ultrasonic imagers and includes an on-chip adaptive beamformer and Charge-Redistribution TX (CR-TX) to provide a drive strength of up to 500 pF/channel at 5 MHz (or 10 nF at 250 kHz) while reducing the TX drive power by at least 30% compared to other ultrasonic transducer TX drivers. The ultrasonic transducer interface system can be implemented in a single chip via, for example, a complementary metal oxide semiconductor (CMOS) process.

Noise present in ultrasonic tests applied by an ultrasonic test system to test objects, e.g., production parts, is reduced to provide more accurate results and to reduce waste, e.g., by reducing the number of test objects inaccurately identified as faulty. To that end, a noise signature is obtained for an ultrasonic test applied by the ultrasonic test system to a known object having the same dimensions and the same material composition as the test objects. The noise present in the output of the ultrasonic test applied by the ultrasonic test system to one or more of the test objects is then reduced responsive to the obtained noise signature to improve the accuracy of the ultrasonic test.

Various embodiments include a method for determining the mixing ratio R of a fluid comprising a mixture of at least two different fluids for a technical process in a device comprising: irradiating an ultrasonic signal with a transmission level along a measuring distance running inside a measuring section; measuring a receiving level of the ultrasonic signal at one end of the measuring distance; determining an ultrasonic attenuation of the ultrasonic signal attenuated by the fluid based at least on the transmission and receiving levels of the ultrasonic signal; measuring a temperature of the fluid flowing through the measuring section; and determining a mixing ratio of the at least two different fluids from the determined ultrasonic attenuation and from the measured fluid temperature.

In a first aspect, the present description relates to a system for non-invasively characterizing a heterogeneous medium using ultrasound, comprising at least one first array (10) of transducers configured to generate a series of incident ultrasound waves in a region of said heterogeneous medium and record the ultrasound waves which are backscattered by said region as a function of time, as well as a computing unit (42) which is coupled to said at least one first array of transducers and configured to: record an experimental reflection matrix defined between an emission basis at the input and the basis of the transducers at the output; determine, from said experimental reflection matrix, at least one first wideband reflection matrix defined in a focused base at the input and output; determine a first distortion matrix defined between said focused basis and an observation basis, said first distortion matrix resulting, directly or after a change of basis, from the term-by-term matrix product of said first wideband reflection matrix defined between said focused basis and an aberration correction basis, with the phase-conjugated matrix of a reference reflection matrix defined for a model medium, between the same bases; determine, from said first distortion matrix, at least one mapping of a physical parameter of said heterogeneous medium.