Abstract: The present disclosure provides a system and method for estimating fracture density within a subsurface formation from S-wave seismic data. In one embodiment, the S-wave seismic data is separated into fast (“S1”) and slow (“S2”) data. A computer is used to compute local similarity of the S1 and S2 data and to compute a cumulative time-difference by which the S2 data lags the S1 data from the local similarity. Based on the computed cumulative time-difference, the fracture density of a subsurface formation is estimated.

Abstract: An object information acquisition apparatus according to an embodiment of the present invention includes a plurality of transducer elements each configured to transmit an acoustic wave to an object, to receive reflected waves reflected from inside the object, and to convert the reflected waves into a time-series reception signal; and a processor configured to perform frequency domain interferometry combined with adaptive signal processing by using the reception signals output from the plurality of transducer elements and a reference signal so as to obtain acoustic characteristics at a plurality of positions located inside the object. The processor is configured to switch the reference signal to another reference signal at least once in accordance with a target position located inside the object while performing the frequency domain interferometry so as to obtain the acoustic characteristics at the plurality of positions located inside the object.

Abstract: A synthetic underwater visualization system (SUVS) comprising a real-time graphics software engine, a sophisticated underwater environmental sensor, a fixed-base database, and a retrieval system designed to accept and assimilate into a common database bathymetric and environmental information acquired from around the world by components of other deployed SUVS sensing systems. SUVS is capable of sensing, modeling, and realistically displaying underwater environments in real-time, and will foster widespread utilization in the areas of homeland security, commercial and recreational maritime navigation, bathymetric data collection, and environmental analysis. The technology will also be readily adaptable and highly desirable in non-marine applications.

Abstract: A method for maximizing a repeatability between a base seismic survey and a monitor seismic survey of a same surveyed subsurface during a 4-dimensional (4D) project. The method includes receiving first seismic data associated with the base seismic survey; receiving second seismic data associated with the monitor seismic survey, wherein the monitor seismic survey is performed later in time than the base seismic survey; estimating subsurface reflection-points and incidence angles; determining 4D-binning based on the estimated subsurface reflection-points and incidence angles; and maximizing the repeatability between the first seismic data and the second seismic data by using the 4D-binning.

Abstract: A device for deflecting acoustic waves for an object in a liquid environment includes an electrical power source located in the object. A heating grid is positioned about the object in the liquid environment, and a cooling grid is also positioned about the object in the liquid environment such that the heating grid is located between the object and the cooling grid. A least one Peltier device is joined to the electrical power source and the cooling grid for providing cooling. Resistance heating or the Peltier device can be joined to the heating grid for providing heating.

Abstract: The quality of ping-based ultrasound imaging is dependent on the accuracy of information describing the precise acoustic position of transmitting and receiving transducer elements. Improving the quality of transducer element position data can substantially improve the quality of ping-based ultrasound images, particularly those obtained using a multiple aperture ultrasound imaging probe, i.e., a probe with a total aperture greater than any anticipated maximum coherent aperture width. Various systems and methods for calibrating element position data for a probe are described.

Abstract: A data transmission device includes a coder configured to code the data into a multifrequency signal. A first array of ultrasonic transducers with a vibrating membrane is disposed on a first surface of a wafer. The first array configured to convert the signal into a multifrequency acoustic signal propagating in the wafer. A second array of ultrasonic transducers is disposed on a second surface of the wafer. The second array includes at least two assemblies of vibrating membrane ultrasonic transducers having resonance frequencies equal to two different frequencies of the multifrequency signal.

Abstract: An object detection method using ultrasonic waves includes: emitting a plurality of ultrasonic signals sequentially according to a time interval; sensing a sound wave formed by each of the ultrasonic signals to generate a reflected signal; and analyzing the reflected signal to detect at least one reflection object. It can be clearly known whether a reflection object is appearing, moving and the moving direction by the method.

Abstract: A method for localizing signals of interest includes initializing characteristics of the signals. Signals are acquired from a sensor array having at least three acoustic sensors. After digitization and conditioning, the signals associated with each sensor are validated by comparison with initialized characteristics. The signals are correlated across sensor groups to obtain time differences of arrival (TDOA). These TDOA are validated and associated with other TDOA from different times. TDOA from different sensor pairs are associated when they share a common sensor. A hyperbola of possible locations is created for each validated TDOA. Summation of the hyperbolas gives an intensity function. The location is identified as the most intense point in the intensity function. The source can be tracked across time as a computer output.

Abstract: A transmission circuit transmits an ultrasonic signal from an ultrasonic vibrator by driving a terminal voltage of the ultrasonic vibrator using a first pulse signal and then further driving the terminal voltage using a second pulse signal having an opposite phase to the first pulse signal. At least one of a pulse number of the second pulse signal and a pulse level of the terminal voltage is arbitrarily set.

Abstract: An acoustic-sensing underwater tow cable includes a cable core for transmission of power/signals there along, a first jacket encasing the cable core, and discrete regions of carbon nanotubes affixed to the first jacket. The carbon nanotubes at each of the discrete regions define an acoustic sensor. A second jacket encases each acoustic sensor and any electrical conductors coupled thereto.