Abstract: There is provided an ultrasonic diagnosis apparatus capable of reducing an unnecessary signal component in a reception signal. A plurality of sign bits arranged in the channel direction are extracted from a plurality of element reception signals. A binarization circuit applies binarization processing to the plurality of sign bits to thereby generate a sign data array. An evaluation value computing unit computes an evaluation value (GSCF) based on a DC vicinity component contained in the sign data array on the frequency axis. This evaluation value is used to adjust the gain of the reception signal in a multiplier. With application of the binarization processing, excessive reduction of the reception signal can be prevented. Further, as the DC vicinity component is referenced, the side-lobe component can be appropriately reduced even if a certain degree of fluctuation exists in the main-lobe component.

Abstract: There is disclosed a transducer apparatus for acoustic communications through a substrate at a predetermined center frequency, the apparatus comprising:—an active piezoelectric element for generating an acoustic signal; an intermediate layer, having a surface for accommodating the piezoelectric element, and having a first array of protrusions on a surface opposite the surface for accommodating the piezoelectric element; and a second array of protrusions at the substrate, wherein the active piezoelectric element is mounted onto the intermediate layer, and the intermediate layer is secured in position relative to the substrate such that the first array of protrusions faces the second array of protrusions such that the acoustic signal may propagate through the first and second arrays. There are further disclosed a method of mounting such an apparatus and a plate suitable for use in the transducer apparatus.

Abstract: A method for designing an acoustic array includes establishing a desired beam pattern, acoustic wavelength and beamwidth for the array. Geometric parameters are calculated from these constraints. The array is modeled as a plurality of elements positioned in accordance with the geometric parameters. An amplitude shading function is calculated. An array of acoustic elements is constructed having an area calculated from the calculated amplitude shading function. An acoustic array designed by this process is further provided.

Abstract: A low-loss high-voltage multiplexer is implemented using a transformer that is connected to one transmitter, one receiver and transducer elements. At least one primary winding is magnetically coupled at least two secondary windings. For example, a first transducer element and a second transducer element are connected to the secondary windings of a multiplexer that multiplexes between these transducer elements via the secondary windings. The multiplexer also optionally switches between the transmitter and the receiver during the transmission and the reception.

Abstract: The position of a mobile unit (12) within a detection zone is determined. An acoustic signal is emitted from the mobile unit and received along a first path (54). An echo of the signal is received after reflection from a surface (46) within said detection zone. The position of the mobile unit (12) within the detection zone is determined from the times of arrival of the signal and echo.

Abstract: An ultrasonic locationing system includes an emitter operable to emit at least two ultrasonic frequency tones sequentially in one ultrasonic burst. These tones, which may contain multiple frequency components, define a unique regional address. A mobile device with a microphone is operable to receive the ultrasonic burst and have a processor determine the sequential tones. A location of the device can be found from a table of predefined tones assigned to known regional addresses.

Abstract: Embodiments of performing beam forming processing based on sampling data in an ultrasound system are disclosed. The ultrasound system includes an ultrasound data acquisition unit configured to form a receive signal based on an ultrasound signal reflected from a target object, perform an analog-to-digital conversion on the receive signal to form sampling data, select pixels, which the respective sampling data are used as pixel values thereof among the plurality of pixels, cumulatively assign the corresponding sampling data to the selected pixels and perform beam forming upon the cumulatively assigned sampling data for the respective pixels to form receive-focused data.

Abstract: The dereverberation of signals in reverberating environments is carried out via acquiring the representation (image) of spatial distribution of the signals in space of interest and automatic identification of reflections of the source signal in the reverberative space. The technique relies on identification of prominent features at the image, as well as corresponding directions of propagation of signals manifested by the prominent features at the image, and computation of similarity metric between signals corresponding to the prominent features in the image. The time delays between the correlated signals (i.e., source signal and related reflections) are found and the signals are added coherently. Multiple beamformers operate on the source signal and corresponding reflections, enabling one to improve the signal-to-noise ratio in multi-path environments.

Abstract: The subject matter disclosed herein relates to determining a distance from a mobile device to a remote object or a size of the remote object.

Abstract: Sub-aperture control is provided for high intensity focused ultrasound. Test transmissions are made sequentially from different sub-apertures. The tissue response at the focal regions is determined and used to select sub-apertures. For example, one or more sub-apertures are not used where temperature does not rise above certain threshold or tissue displacement is weak, such as associated with intervening bone or attenuating tissue. Other factors may be used instead or in addition to tissue response at the focal region. Relative proximity of the sub-apertures to a lesion, angular distribution of the sub-apertures, shape or size of the sub-aperture focal regions as compared to the tissue to be treated, or combinations thereof may be used. Once selected, the relative weight for each sub-aperture may be adjusted based on measured tissue response for each sub-aperture, such as to provide more equal treatment contribution from different sub-apertures.

Abstract: Acoustic arrays transmitting and/or receiving multiple, angularly dispersed acoustic beams are used to generate 2D and 3D images. The acoustic arrays may comprise frequency-steered acoustic arrays provided in one-dimensional linear and two dimensional planar and curvilinear configurations, which may be operated as single order or multiple order arrays, may employ periodic or non-periodic transducer element spacing, and may be mechanically scanned to generate 2D and 3D volumetric data. Methods and systems for operating acoustic arrays in a frequency-steered mode in combination a mechanical beam steering mode, electronic time-delay and phase shift beam forming modes, and phase comparison angle estimation modes are also provided. Methods for generating two and three dimensional images of underwater target scenes using multi-beam acoustic imaging systems are disclosed.

Abstract: In a method and a device for determining the position of an object in relation to a vehicle, for use in a driver assistance system of the vehicle, a first ultrasound pulse is transmitted by an ultrasound sensor situated on the vehicle, the ultrasound pulse including multiple predefined transmission frequencies which result in a variation of the directional characteristic of the ultrasound sensor. The transmitted first ultrasound pulse is reflected on the object and is received again as a first echo pulse. A frequency spectrum of the first echo pulse is subsequently determined, and a first absolute value of a relative offset angle of the object is determined as a function of the frequency spectrum of the first echo pulse and the directional characteristics.

Abstract: A method for pre-determining an underwater objects GPS position using a rotatable scan sonar unit linked to a boat, magnetic compass and GPS receiver. This system determines the underwater objects GPS position using the objects distance, compass heading and a GPS receiver/sonar on a boat. This system will provide real time longitude and latitude positions of underwater objects seen with sonar at a distance from a boat, and will allow for precise autopilot navigation or fixed position fishing. The system can also be used to correct for GPS errors when using previously stored waypoints positions of an object. The computer determines an objects underwater GPS position using a sonar transducer and mounted on a 360 degree movable mechanism such as a trolling motor unit, or phased array of transducers and a compass to provide heading information and formulates the objects position based on the distance and heading of the object in relation to the boats current GPS position.

Abstract: A method of ultrasound receive beamforming includes receiving a first plurality of sensing signals from target tissue, forming a first plurality of digital sensing signals, and data processing the digital sensing signals along a first plurality of data paths to form a first plurality of delayed and apodized digital sensing signals. Data path combining generates data combinations of the delayed and apodized digital sensing signals to include two or more of the delayed and apodized digital sensing signals that originate from different ones of the transducer elements. The data combinations are interpolation filtered using a plurality of interpolation filters to form a second plurality of delayed and apodized digital sensing signals, which are then summed to form an ultrasound receive beamformed signal. The interpolation filters can be interpolation filters in a single shared filter bank, with each interpolation filter providing a different fractional delay.

Abstract: Frequency-steered acoustic arrays transmitting and/or receiving multiple, angularly dispersed acoustic beams are used to generate 2D and 3D images. Input pulses to the arrays are generally non-linear, frequency-modulated pulses. Frequency-steered acoustic arrays may be provided in one-dimensional linear and two dimensional planar and curvilinear configurations, may be operated as single order or multiple order arrays, may employ periodic or non-periodic transducer element spacing, and may be mechanically scanned to generate 2D and 3D volumetric data. Multiple imaging fields of view may generated in different directions by switching the polarity of phase-shifted array transducer elements. Multiple frequency-steered arrays arranged in an X-configuration provide a wide, contiguous field of view and multiple frequency steered arrays arranged in a T-configuration provide orthogonally oriented fields of view.

Abstract: A method and apparatus for determining presence of an object to be tidied in a washroom. A beam is supplied to a surface of the washroom at a first location. A reflected beam received from the surface of the washroom or received from an object in the path of the beam to the surface is detected. The presence of the object is determined from feedback from the beam based on a comparison of the feedback with a detection result when the beam reflects from the surface at the first location. An object to be tidied output signal is issued indicating that an object to be tidied is present based on the determination on the presence of an object.

Abstract: The invention provides a method for determining a set of filter coefficients for an acoustic echo compensator in a beamformer arrangement. The acoustic echo compensator compensates for echoes within the beamformed signal. A plurality of sets of filter coefficients for the acoustic echo compensator is provided. Each set of filter coefficients corresponds to one of a predetermined number of steering directions of the beamformer arrangement. The predetermined number of steering directions is equal to or greater than the number of microphones in the microphone array. For a current steering direction, a current set of filter coefficients for the acoustic echo compensator is determined based on the provided sets of filter coefficients.

Abstract: The subject matter disclosed herein relates to determining a distance from a mobile device to a remote object or a size of the remote object.

Abstract: A method for locating the surface of a solid growth culture medium in a plate in a plate work position, the plate work position including a sensor and having a datum level fixed in one dimension (z), the method including: placing the plate in the plate work position; using the sensor to sense the medium surface for the positioned plate and measuring the distance to the medium surface; and referencing the measured distance to the datum level to determine a surface positional reference, relative to the datum level, in one dimension (z) for the surface of the medium in the positioned plate.

Abstract: The present disclosure relates to a method for generating a synthetic image. In the method, image data is generated using a receiving dynamic beamforming method, image data is generated using a synthetic aperture beamforming method, and the image data generated using the receiving dynamic beamforming method and the image data generated using the synthetic aperture beamforming method are synthesized with being applied with weighting factors according to advancing distances of ultrasonic waves. By using a zone blending method, in which image data according to a receiving dynamic beamforming method is mainly used for an ultrasonic image having a predetermined depth or less, and image data according to a synthetic aperture beamforming method is mainly used for an ultrasonic image having any other depth, a grating lobe and distortion of image brightness are eliminated.

Abstract: There are provided an oscillation device that outputs a sound wave; a recognition unit that recognizes a direction in which sound output targets (80), for which a sound is to be output, are located; a selection unit that selects at least one of the sound output targets (80); a distance calculation unit that calculates a distance to the sound output target (80); and a control unit that controls the oscillation device to adjust sound pressure of the sound wave. The oscillation device outputs an ultrasonic wave for a sensor and a sound wave for sound reproduction. The distance calculation unit calculates a distance between the oscillation device and an object to be selected (82) by detecting the ultrasonic wave for a sensor reflected from the object to be selected (82) selected by the selection unit. The control unit adjusts the magnitude of the output of the sound wave for sound reproduction on the basis of the calculated distance between the oscillation device and the object to be selected (82).

Abstract: A system is employed for defining a position (location) of a receiving element inside an area surrounded by a wire loop, along the perimeter (a perimeter wire loop), of a work area or other bounded area. In particular, the system can determine whether the receiver is inside or outside the loop, and evaluate its distance from the perimeter wire.

Abstract: An electronic array probe for ultrasonic imaging includes an array of transmitting and/or receiving electroacoustic transducers arranged in concentric bands in which the transducers are tangent to one other in both radial and circumferential directions. In order to minimize the number of transducers required without compromising dynamic range, a transducer arrangement geometry is provided so that the number of transducers having the same focusing delay is minimal or null.

Abstract: A method for pre-determining an underwater objects GPS position using a rotatable scan sonar unit linked to a boat, magnetic compass and GPS receiver. This system determines the underwater objects GPS position using the objects distance, compass heading and a GPS receiver/sonar on a boat. This system will provide real time longitude and latitude positions of underwater objects seen with sonar at a distance from a boat, and will allow for precise autopilot navigation or fixed position fishing. The system can also be used to correct for GPS errors when using previously stored waypoints positions of an object. The computer determines an objects underwater GPS position using a sonar transducer and mounted on a 360 degree movable mechanism such as a trolling motor unit, or phased array of transducers and a compass to provide heading infromation and formulates the objects position based on the distance and heading of the object in relation to the boats current GPS position.

Abstract: A computer-implemented method of sonar processing includes identifying, with a processor, a detection having a detection probability value, the detection in a selected beam, wherein the detection is associated with a detection range cell having detection range cell data. The method also includes comparing, with the processor, the detection range cell data with range cell data from a corresponding range cell from at least one overlapping beam overlapping the selected beam. The method also includes updating, with the processor, the detection probability value based upon the comparing. A sonar system uses the above-described method. A computer readable storage medium has instructions thereon to achieve the above-described method.

Abstract: A beamforming method includes generating a control signal for implementing a delay time for each of a plurality of transducers of each of a plurality of two-dimensional (2D) transducer-arrays, transmitting the control signal to a plurality of driving units respectively corresponding to the plurality of 2D transducer-arrays via an interposer that electrically connects the plurality of 2D transducer-arrays to each other, and driving each 2D transducer-array of the plurality of 2D transducer-arrays with a corresponding driving unit of the plurality of driving units according to the control signal transmitted via the interposer.

Abstract: An apparatus and a method for the binaural reproduction of audio sonar signals, which can be direction-selectively received by a sonar system having a receiving antenna provided with a plurality of transducers, and at least one direction generator, and which can be modified by binaural audio signal processing. The apparatus comprises a portable sound reproduction device, particularly a headphone, and a head tracking sensor connected to the sound reproduction device for registering position changes of the sound reproduction device. Signals, associated with the position changes, are generated, which are transferred to the direction generator, in order to select a direction of the sound waves to be received.

Abstract: Systems and methods for coherent image correlation are provided. The systems include sonars with overlapping frequencies that observe terrain from overlapping aspects to form sonar images. First and second sonar images are formed and are grazing angle compensated. The first image is formed using the open or closed aperture theorem. Forming the second image using the open or closed aperture theorem constraint is optional. If the first and second images are not aligned, a range of possible rotations can be defined and image pairs can be created for a sampling of rotational angles. In addition, the images can be aspect compensated to remove windowing and beam pattern effects, if necessary. Once both images are grazing angle compensated and aligned, values are calculated for each possible image shift. To obtain a correlation image, the correlation coefficient for each possible image shift is calculated.

Abstract: Disclosed is a security monitoring method determining whether a trespasser is detected and a position of the trespasser in a set security space and monitoring sound generated at the position of the trespasser by using an acoustic image generated from acoustic signals generated by an acoustic generating device and an acoustic measuring device in an array type. An exemplary embodiment of the present disclosure provides a security monitoring system including: an acoustic generating device that generates acoustic signals; a plurality of acoustic measuring devices that receive the acoustic signals; and an acoustic image processing device that generates an acoustic image using a beamforming algorithm from the acoustic signals received in the plurality of acoustic measuring devices and determines a position of a trespasser by comparing the acoustic image after the trespasser is detected with the acoustic image before the trespasser is detected.

Abstract: The sounder according to the invention comprises two transmit-receive antennas (1, 10) whose respective axes are off-target toward the front, in the direction of movement of the platform, these axes being symmetrical relative to a straight line (3) passing through their intersection and parallel to the axis of travel of the platform, the transmit frequency of the first antenna, equal to the receive frequency of the second being different from the transmit frequency of the second, the latter frequency being equal to the receive frequency of the first.

Abstract: A system is employed for defining a position (location) of a receiving element inside an area surrounded by a wire loop, along the perimeter (a perimeter wire loop), of a work area or other bounded area. In particular, the system can determine whether the receiver is inside or outside the loop, and evaluate its distance from the perimeter wire.

Abstract: The dereverberation of signals in reverberating environments is carried out via acquiring the representation (image) of spatial distribution of the signals in space of interest and automatic identification of reflections of the source signal in the reverberative space. The technique relies on identification of prominent features at the image, as well as corresponding directions of propagation of signals manifested by the prominent features at the image, and computation of similarity metric between signals corresponding to the prominent features in the image. The time delays between the correlated signals (i.e., source signal and related reflections) are found and the signals are added coherently. Multiple beamformers operate on the source signal and corresponding reflections, enabling one to improve the signal-to-noise ratio in multi-path environments.

Abstract: An accurate real-time measurement of a displacement vector is achieved on the basis of the proper beamforming that require a short time for obtaining one echo data frame without suffering affections by a tissue motion. The displacement measurement method includes the steps of: (a) yielding ultrasound echo data frames by scanning an object laterally or elevationally using an ultrasound beam steered electrically and/or mechanically with a single steering angle over an arbitrary three-dimensional orthogonal coordinate system involving existence of three axes of a depth direction, a lateral direction, and an elevational direction; and (b) calculating a displacement vector distribution by implementing a block matching on the predetermined ultrasound echo data frames yielded at more than two phases.

Abstract: A parking assisting apparatus and method that can precisely estimate the orientation of a parking space. A parking assisting apparatus for assisting parking a vehicle includes an obstacle detecting mechanism that detects an obstacle near the vehicle and an orientation information acquiring mechanism that acquires information as to an orientation of the vehicle. The apparatus estimates an orientation of the parking space that may exist near the vehicle based on the detection result of the obstacle detecting mechanism and the orientation information.

Abstract: Methods and systems for detecting features in thin-wall structures are provided. A plurality of ultrasonic waves are generated within a thin-wall structure. At least one echo from the plurality of ultrasonic waves within the thin-wall structure is detected. The at least one echo is processed to determine a position of at least one feature in the thin-wall structure based on Embedded Ultrasonic Structure Radar (EUSR) beamforming performed in the frequency domain.

Abstract: An object is detected without being constrained by the positional relationship between the object and the detecting position. A detection device includes a pseudo sound source and a monitoring unit. The pseudo sound source generates a scanning sound wave of a phase-conjugate wave in the time domain based on an acoustic signal by performing active phase conjugation, and causes the scanning sound wave to converge on the detection object from the above thereof within the propagation space by utilizing a feature that the scanning sound wave converges on the pseudo sound source which is the generation source of the acoustic signal. The monitoring unit extracts a reflected sound wave which is reflected at the detection object from the sound wave in the propagation space by performing passive phase conjugation. The detection object is detected based on presence or absence of the extracted reflected wave.

Abstract: A vessel-mountable integrated sonar system is provided. The vessel-mountable integrated sonar system comprises at least one imaging sonar data acquisition device and at least one processing system electronically and removably connected to the at least one imaging sonar data acquisition device, wherein the sonar data acquisition device preferably provides acoustic data to the processing system, producing sonar imageries utilizing the acoustic data, and wherein the system provides digital tilt and azimuth direction feedback for accurate geo-referencing of data to localize targets of interest.

Abstract: A counter-terrorism underwater surveillance system for detecting swimming intruders includes a sonar array 20 comprising a plurality of sensor elements which both transmit and receive acoustic signals. Power amplifiers 22 generate electric transmit signals which are converted to acoustic form for transmission by the sonar array 20. Incoming acoustic signals, including echo data from any intruder in the water, are received by the sonar array 20 and passed to a data acquisition subsystem 24, which digitises the data for processing. The digitised data is passed to a beamforming subsystem 26 which forms defined beams from omni-element data. A detection processing subsystem 28 then extracts signals from noise and reverberation and passes these to a display processing subsystem 30 which defines tracks from the intruder echo data. Finally, intruder images and tracks are displayed on a display subsystem 32.

Abstract: A beamforming system includes an array of transducers that detects echo signals in a scanned region. The array of transducers produces respective electronic signals based on receipt of echo signals. The beamforming system further includes an array of multipliers (e.g., mixers) to receive the respective electronic signals (e.g., echo signals converted to an electronic form of echo signals by the transducers) from the array of transducers. A generator device of the beamforming system generates multiple oscillator signals (e.g., square wave, sine waves, pulses, etc.) based on a relatively low frequency reference signal to simulate frequencies not capable of being precisely derived from the reference signal and continuously steer a directional beam through a scanned region.

Abstract: A system and method are provided for automatically tracking the movements of an acoustic source relative to two or more microphones possibly mounted in a portable device. The microphones are mounted so that they may be separated from an acoustic source that can be more than three inches from the portable device. By automatically tracking the location of a portable device, a directional response of unidirectional microphones in a far field setting can be steered so that the radial axis of the directional response aligns with the path in which the acoustic wave travels from the source to the microphones. By tracking the source and steering the directional response of the microphones, the system can thereby properly delay and filter electrical signals added to the outputs from corresponding microphones to maximize the signal-to-noise ratio of the ensuing signal.

Abstract: An obstacle detection apparatus includes an ultrasonic sensor and a control part. The ultrasonic sensor detects a presence of an obstacle around a vehicle and a distance to the obstacle by transmitting an ultrasonic wave and receiving the ultrasonic wave reflected by the obstacle. The control part includes at least one of a rainfall amount determining portion and a noise determining portion. When the rainfall determining portion determines that a rainfall amount is greater than a predetermined amount or when the noise determining portion determines that noise is present, the control part outputs a command signal to the ultrasonic sensor so that the ultrasonic sensor decreases a directivity compared with a case where the rainfall determining portion determines that the rainfall amount is less than or equal to the predetermined amount or a case where the noise determining portion determines that noise is not present.

Abstract: This invention provides methods and apparatus for focusing a hypersonic beam to control both a direction and depth of audible information delivery. Signals that are delivered to each of a plurality of hypersonic transducer elements are adjusted in phase so that transmitted hypersonic signals are focused at a focal point anywhere in space. The focal point of a focused hypersonic beam may be used to scan a space of interest when used in a receive mode in a pinging process. When objects are detected, a focused hypersonic beam may be used to deliver audible information substantially only to a neighborhood of the detected object.

Abstract: A moving object detection apparatus comprises a transmitter, a receiver, a detection portion, a binary conversion portion and a judgment portion. The transmitter emits energy waves with a first frequency to a detection area. When receiving incoming energy waves from the detection area, the receiver generates an electric signal corresponding to the incoming energy waves. The detection portion obtains a detection signal from a reference signal with the first frequency and the electric signal. The binary conversion portion compares the detection signal with a conversion threshold signal to obtain a binary signal. The judgment portion judges whether or not a moving object approaching or leaving the receiver exists in the detection area based on the binary signal.

Abstract: An imaging system comprises a device to excite mechanical waves in elastic tissue, a device for measuring the resulting tissue motion at a plurality of locations interior to the tissue at a number of time instances, a computing device to calculate the mechanical properties of tissue from the measurements, and a display to show the properties according to their location. A parameter identification method for calculating the mechanical properties is based on fitting a lumped dynamic parametric model of the tissue dynamics to their measurements. Alternatively, the mechanical properties are calculated from transfer functions computed from measurements at adjacent locations in the tissue. The excitation can be produced by mechanical vibrators, medical needles or structures supporting the patient. The measurements may be performed by a conventional ultrasound imaging system and the resulting properties displayed as semi-transparent overlays on the ultrasound images.

Abstract: A system for use with a boat to provide underwater sonar images includes a GPS receiver for providing GPS position data, a left side scan sonar transducer for transmitting left side scan sonar pulses and for receiving left side scan sonar return signals, and a right side scan sonar transducer for transmitting right side scan sonar pulses and for receiving right side scan sonar return signals. The system further includes signal processing circuitry for processing the left and right side scan sonar return signals to produce side scan image data and a digital processor for causing a display to display an underwater image based upon the side scan image data, wherein the digital processor associates GPS position and side scan image data.

Abstract: Frequency-steered acoustic arrays transmitting and/or receiving multiple, angularly dispersed acoustic beams are used to generate 2D and 3D images. Input pulses to the arrays are generally non-linear, frequency-modulated pulses. Frequency-steered acoustic arrays may be provided in one-dimensional linear and two dimensional planar and curvilinear configurations, may be operated as single order or multiple order arrays, may employ periodic or non-periodic transducer element spacing, and may be mechanically scanned to generate 2D and 3D volumetric data. Multiple imaging fields of view may generated in different directions by switching the polarity of phase-shifted array transducer elements. Multiple frequency-steered arrays arranged in an X-configuration provide a wide, contiguous field of view and multiple frequency steered arrays arranged in a T-configuration provide orthogonally oriented fields of view.

Abstract: A medical diagnostic ultrasound system comprises several subsystems, such as a transmit beamformer, a receive beamformer, a B-mode processor, a Doppler processor and a scan converter. These subsystems are within the ultrasound data processing path for processing ultrasound data. One or more of these subsystems are implemented with one or more re-programmable logic devices. For example, one or two field programmable gate arrays are used is each subsystem to perform most or almost all of the subsystems essential functionality.

Abstract: A vessel-mountable integrated sonar system is provided. The vessel-mountable integrated sonar system comprises at least one imaging sonar data acquisition device and at least one processing system electronically and removably connected to the at least one imaging sonar data acquisition device, wherein the sonar data acquisition device preferably provides acoustic data to the processing system, producing sonar imageries utilizing the acoustic data, and wherein the system provides digital tilt and azimuth direction feedback for accurate geo-referencing of data to localize targets of interest.

Abstract: A capacitive microfabricated ultrasonic transducer (cMUT) is operated to improve its performance during harmonic imaging in non-linear media, such as in contrast agents or in human tissue. The cMUT is operated by inverting the transmit waveform to adjacently spaced azimuth elements, and combining at least two additional firings without adjacent inversion, for each transmit vector, thereby canceling the second harmonic generation of the cMUT; and thus, the performance of harmonic imaging using the cMUTs can achieve improvement.

Abstract: A sonar array for forming multiple transmit and/or receive acoustic beams by a frequency beamforming technique. In frequency division beamforming, beam steering direction is made a function of frequency by driving (receiving) each element of a uniformly spaced line array by a signal which leads or lags its nearest neighbor by a fixed phase shift, ??. This permits scanning a transmit and/or receive beam through a range of angles by changing its frequency. The same principle can be used to form multiple simultaneous transmit and/or receive beams. This is accomplished by transmitting a wide bandwidth signal and receiving the echoes through a spectrum analyzer. Each frequency bin of the spectrum analyzer then corresponds to a beam pointing in its own unique direction. Advantages of such a sonar system include improved cost, weight, and size versus performance for a variety of systems including ahead looking sonars and bottom mapping sonars.