Abstract: A sonar system and method of operating a sonar system are disclosed. In one embodiment, the sonar system comprises an array of transducers and a multiplexer configurable into a plurality of states. In one embodiment, the multiplexer, when in a first state, electrically couples a plurality of connections with the plurality of transducers via a first mapping and, in a second state, electrically couples the plurality of connections with the plurality of transducers via a second mapping.

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: A sonar transducer network for observing a seabed includes a controller. A first transducer assembly includes a first acoustic transducer to convert a first ping to a first electrical signal; and a first transducer processor to receive a first electrical signal from the first acoustic transducer to generate the first transducer data. At least one second transducer assembly is spaced apart from the first transducer assembly. The second transducer assembly includes a second acoustic transducer to convert a second ping to a second electrical signal. The second transducer processor receives the second electrical signal from the second acoustical transducer to generate second transducer data. A network bus communicates first transducer data and second transducer data with the controller.

Abstract: The present invention is about an unmanned boat automatic survey device and an unmanned boat automatic surveying method that automatically generate survey routes and automatically survey underwater and water bottom conditions under the survey routes. Under the present invention, a reference survey line is entered for generating a survey route (S1), and a plurality of survey routes are generated by translating the reference survey line at a fixed distance (S2). It then determines the distances of the generated survey routes and instructs a traversing order of the determined survey routes (S3), and causes the unmanned boat to navigate automatically according to the instructed traversing order. It surveys at least underwater or water bottom condition during the navigation (S5), and display and store the surveyed underwater or water bottom condition (S6).

Abstract: A system for use with a boat to provide underwater sonar images includes 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 providing signals to a display based upon the side scan image data to produce a display image on the display showing boat location, a water column between the boat and bottom, and an underwater image comprising at least one of a left side underwater image and a right side underwater image.

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: In some embodiments, a sonar system may include one or more of the following features: (a) a microcontroller electronically coupled to a receiver, (b) a transmitter electronically coupled to the microcontroller and the receiver, (c) a transducer electronically coupled the transmitter and the receiver, the transmit frequency of the transmitter being auto tuned to a best echo frequency of the transducer, (d) a display electronically coupled to the microcontroller, and (e) a keyboard electronically coupled to the microcontroller.

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: A system for assessing underwater biomass that comprises a frame that can float and hold the system on a body of water; a transducer that emits and receives wave signals; a motor box, that positions the transducer below a water line; a control unit to allow a user to operate the system and view results obtained from the system; an electronics housing that receives a CPU board that communicates with and relays information to and from, the control unit; and a communication device to facilitate communication between the control unit and the CPU board.

Abstract: A process and apparatus for detecting underwater objects comprises an elongate array of ultrasound transmitter elements mounted substantially vertically and forward facing on the bow of the ship from which is transmitted a sequence of ultrasound wave pulses, with each pulse having a frequency and vertical beam angle which are different to the frequency and vertical beam angle of the preceding pulse in the sequence, the frequency being characteristic of the vertical beam angle and the vertical beam angle being controlled by using time delays between different transmitter elements, and an elongate array of ultrasound receiver elements mounted substantially horizontally on the bow of said ship with the receiver elements forward facing which receive any ultrasound waves reflected from objects in front of the ship, the output from the receiver elements being steered horizontally using time delays between different receiver element outputs and for each horizontal position of the beam of outputs, the outputs from th

Abstract: A sonar transducer network for observing a seabed includes a controller. A first transducer assembly includes a first acoustic transducer to convert a first ping to a first electrical signal; and a first transducer processor to receive a first electrical signal from the first acoustic transducer to generate the first transducer data. At least one second transducer assembly is spaced apart from the first transducer assembly. The second transducer assembly includes a second acoustic transducer to convert a second ping to a second electrical signal. The second transducer processor receives the second electrical signal from the second acoustical transducer to generate second transducer data. A network bus communicates first transducer data and second transducer data with the controller.

Abstract: Disclosed herein is a method of constructing an environmental map using sonar sensors. The method includes the steps of checking whether conflict cells have occurred using input sonar sensor data; if conflict cells have occurred, selecting incorrect data and eliminating the conflict cells using sound pressure comparison until the conflict cells do not occur any longer; and once the elimination has completed, preparing a grid map using a Maximum Approximated Likelihood (MAL) approach. Inconsistency in data occurs when multiple pieces of sensor data overlap each other, the conflict cells are cells that experience inconsistency over an entire arc region, and candidates for the incorrect sonar sensor data are obtained when the conflict cells occur.

Abstract: Methods and systems to detect changes in a region of space relative to baseline measurements, including to process data to detect potential objects, or contacts against a natural background environment, to characterize and geo-register the contacts, to compare and correlate the contacts with a database of known objects, and to report uncorrelated contacts as new objects in the space. Features disclosed herein may be implemented to process image data from a line-by-line image-generation system including, for example, side-looking sonar. Methods and system may be implemented with respect to multi-frequency band sonar data.

Abstract: A sonar imaging system for a watercraft is disclosed. The sonar imaging system comprises a transducer coupled to the watercraft and having at least one side scanning element and at least one bottom scanning element, an electronic control head unit coupled to the transducer and configured to display sonar images. The downward acoustic elements may be circular and the side scan acoustic elements may be rectangular. A software filter may be provided to remove noise generated by a spark plug or other operation of a motor for the watercraft.

Abstract: A sonar system includes at least one transmitter and one flexible antenna including a plurality of sections articulated one after the other, each section being provided with at least one acoustic receiver. The system is equipped with positioning elements making it possible to determine the instantaneous position of each of the receivers, and calculation elements making it possible to reconstruct an image of the seabed by taking account of the instantaneous micromovements of each of the receivers.

Abstract: A method and an electronic search system for operating an automatic device, preferably an automatic lawnmower. The system comprises at least one first electrical cable (1,4,5,6) connected to at least one first signal generator (3,7,8) and at least one sensing system arranged on said device. Said sensing system detects at least one magnetic field being transmitted via said cable (1,4,5,6) and propagating through the air, the sensing system transmitting a processed signal to at least one driving element which contributes to the movements of said device in relation to a surface.

Abstract: A method of processing a temporal sequence of base images from a synthetic aperture system such as a synthetic aperture radar is provided that simplifies the task of identifying moving objects. The method comprises the steps of firstly temporally filtering a plurality of the base images to form a reference image, and secondly normalising the reference image with a base image to form a change detection image. The change detection image has the property that all moving objects are emphasised. Further processing can optionally be performed on the change detection image to remove false targets based on characteristics of the highlighted areas or on a temporal track taken over a plurality of change detection images. The invention allows detection of moving objects without requiring a Doppler return from a target. The invention extends to a system adapted to implement the method, and a computer program.

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 synthetic antenna sonar system, includes: a sonar provided with emission elements and reception elements, the reception elements including a composite physical antenna having N transducers, the sonar being located on a mobile carrier; an inertial unit arranged on the carrier and suitable for measuring instantaneous position and orientation informations of the carrier; a common clock supplying a temporal signal enabling the synchronization of both the inertial unit and the sonar; elements for determining the instantaneous speed of the carrier, the determined speed feeding the inertial unit to correct the draft thereof; and micronavigation elements enabling an image of the seafloor to be obtained through formation of the synthetic antenna channels from K sonar operation recurrences, considering that the physical antenna movement during the carrier displacement is fully known from the informations measured by the inertial unit.

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: A system for use with a boat to provide underwater sonar images, includes a left side scan sonar transducer for transmitting left side scan sonar pulses and for receiving left side scan sonar return signals, a right side scan sonar transducer for transmitting right side scan sonar pulses and for receiving right side scan sonar return signals, and signal processing circuitry for processing the left and right side scan sonar return signals to produce side scan image data. The system further includes a user interface including user inputs and a display and a digital processor for providing signals to the display to show an underwater image based upon the side scan image data, wherein the digital processor, in response to a user command, performs an image enhancement algorithm to enhance the underwater image.

Abstract: A seabed resource exploration system includes: a vibrator 1 for transmitting a sound wave into the sea and receiving a scattered wave in which the sound wave is reflected on a boundary surface between seawater and a mixture of methane gas and methane hydrate, which exists in the seawater; and an analyzer 17 for determining that the methane hydrate exists in a seabed immediately under the mixture when backscattering strength, calculated by the transmitted sound wave and the received scattered wave, is in a predetermined relationship. The predetermined relationship satisfies a relationship that a maximum value of the backscattering strength is ?60 to ?30 dB and an average value of the backscattering strength is ?70 to ?50 dB. The backscattering strength is on a grid obtained by cutting the mixture into round slices in the depth direction by a predetermined width, in a range from the seabed to a predetermined height.

Abstract: A system for use with a boat to provide underwater sonar images includes 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 providing signals to a display based upon the side scan image data to produce a display image on the display showing boat location, a water column between the boat and bottom, and an underwater image comprising at least one of a left side underwater image and a right side underwater image.

Abstract: Embodiments of the present invention include methods and apparatus for the detection of objects using acoustic imaging. Vibrational resonance characteristics of man-made objects may be significantly different from those of the surrounding natural materials, allowing an acoustic image to highlight the position of the object, even if the object is concealed from visual imaging.

Abstract: A sonar transducer network for observing a seabed includes a controller. A first transducer assembly includes a first acoustic transducer to convert a first ping to a first electrical signal; and a first transducer processor to receive a first electrical signal from the first acoustic transducer to generate the first transducer data. At least one second transducer assembly is spaced apart from the first transducer assembly. The second transducer assembly includes a second acoustic transducer to convert a second ping to a second electrical signal. The second transducer processor receives the second electrical signal from the second acoustical transducer to generate second transducer data. A network bus communicates first transducer data and second transducer data with the controller.

Abstract: A computer based system and method for real-time display of co-registered historical and current side scan sonar imagery during a side scan sonar survey. Embodiments also include modules for detection of clutter in the current imagery, identification of features, extraction of snippets, filtering based on predetermined size and shape parameters, and determination if a current feature is the same as a previously identified contact from historical imagery.

Abstract: Data recorded by directing a single sonar beam pulse towards a surface, and recording the reflected sonar signals with a large plurality of detectors, is used to generate a mathematical representation of the surface. The mathematical representation of the surface is chosen to fit the recorded data according to a criterion such as a least squares fit of a plane to the recorded data points. A mathematical representation of on object is built up from a number of non-overlapping mathematical objects such as triangles, each triangle joined to adjoining triangles to form a continuous surface in three dimensions. Images of such mathematical representations are then presented to the observer.

Abstract: A sonar transducer network for observing a seabed includes a controller. A first transducer assembly includes a first acoustic transducer to convert a first ping to a first electrical signal; and a first transducer processor to receive a first electrical signal from the first acoustic transducer to generate the first transducer data. At least one second transducer assembly is spaced apart from the first transducer assembly. The second transducer assembly includes a second acoustic transducer to convert a second ping to a second electrical signal. The second transducer processor receives the second electrical signal from the second acoustical transducer to generate second transducer data. A network bus communicates first transducer data and second transducer data with the controller.

Abstract: A method for classifying a type of bottom on a bottom under a liquid includes the steps of performing an acoustic reflection measurement, in which a first attribute is determined which represents a strength with which acoustic waves are reflected from a location on the bottom through the liquid in a reflection direction. Further, the method includes the steps of performing an acoustic scattering measurement, in which a second attribute is determined of acoustic waves that are scattered form the location on the bottom; providing a search unit, which contains information with regard to different combinations of the values of the first and second attributes, and associates the combinations with respective bottom classifications; and identifying a bottom classification of the location on the basis of the bottom classification which the search unit associates with a combination of the first and second attributes.

Abstract: A forward-looking sonar includes a transducer array which is divided into a first sub array and a second sub array, a first beamforming section for forming a first receiving beam with the first sub array, and a second beamforming section for forming a second receiving beam with the second sub array. The forward-looking sonar receives target echoes from a wide sounding area with these receiving beams. The forward-looking sonar further includes a position measurement section for determining the position of a target based on the direction of the target calculated from a phase difference between the echoes from the target received by the first and second receiving beams by a split-beam method and the distance to the target calculated from time needed for receiving the echoes after transmission.

Abstract: An imaging sonar system develops three-dimensional images of the space below, to the sides, and forward of a ship relative to a fixed frame of reference. Various features permit the system to be used in non-military environments and make possible low cost with substantial capabilities.

Abstract: A method is provided for along-track displacement of an underwater vehicle equipped with a synthetic aperture sonar (SAS) system. The SAS system is operated as the vehicle moves through the water. Using successively-detected acoustic signals, an actual redundant phase center overlap scenario is determined that is indicative of along-track displacement of the underwater vehicle occurring between the successively-detected acoustic signals.

Abstract: A sonar transducer network for observing a seabed includes a controller. A first transducer assembly includes a first acoustic transducer to convert a first ping to a first electrical signal; and a first transducer processor to receive a first electrical signal from the first acoustic transducer to generate the first transducer data. At least one second transducer assembly is spaced apart from the first transducer assembly. The second transducer assembly includes a second acoustic transducer to convert a second ping to a second electrical signal. The second transducer processor receives the second electrical signal from the second acoustical transducer to generate second transducer data. A network bus communicates first transducer data and second transducer data with the controller.

Abstract: A system and method of determining a classification of at least one underwater object is provided. The method includes generating at least one low-resolution imagery of an object from a plurality of frequencies produced by a detection device and extracting at least 5 characteristics of the object within the low-resolution imagery at each of the plurality of frequencies. The method further includes generating at least 15 features from the at least 5 characteristics and classifying the features to determine the identity of the at least one underwater object.

Abstract: A processing method of this invention relates to an angle of arrival estimation technique, where by a high resolution bathymetric sidescan sonar signal process method it measure the micro-geomorphy of the sea bottom. That is the multi-subarray sub-space fitting method. The invention shows that when the array elements number is fixed, no matter there is mutual coupling or not between array elements, there exists one subarray which has the smallest phase estimation standard deviation, the method of this invention overcomes the phase error caused by mutual coupling and enhances the measurement precision.

Abstract: Beams of sampled data are converted into a two-dimensional color map thereof. Fourier transforms are performed on range cells of each beam with each transform being sampled M times where M is defined by M discrete sets of red, green and blue intensity values of a color spectrum. For each range cell in each beam, each sample of the corresponding M-sampled Fourier transform is multiplied by a corresponding one of the red, green and blue intensity values from a corresponding one of the M discrete sets thereof. Each of the resulting M red values, M green values and M blue values are averaged. As a result, a triplet is defined for each range cell by the averaged values. For each triplet, the minimum thereof is used to reduce the triplet's averaged values to thereby form a corresponding re-valued triplet. The resulting array of re-valued triplets are normalized across all of the range cells with the resulting array of re-valued triplets so-normalized being used to generate a two-dimensional color display.

Abstract: Embodiments of the present invention include methods and apparatus for the detection of objects using acoustic imaging. Vibrational resonance characteristics of man-made objects may be significantly different from those of the surrounding natural materials, allowing an acoustic image to highlight the position of the object, even if the object is concealed from visual imaging.

Abstract: A sonar emits an ultrasonic wave into the water from a transducer on the basis of a transmission signal outputted from a transmission circuit, receives an echo reflected in the water with the transducer and converts the echo into an electric signal, and displays underwater information on a display unit on the basis of an echo signal extracted by processing the electric signal. A tailing signal removing unit for removing a tailing signal and extracting only the echo signal is provided in the sonar such that a video of a surface layer fish shoal is clearly displayed on a screen of the display unit without being hidden by a video of the tailing signal.

Abstract: A method and system for synthetic aperture sonar provide improved position estimates of a receive array as in moves through a body of water.

Abstract: The present information comprises the stages of: applying frequency analysis to positional information on a platform, generating virtual positional information on the platform based on a frequency analysis result; extracting a signal based on the generated virtual positional information; and performing a synthetic aperture processing based on the extracted signal, and in this manner, even if the positional information lacking in precision and inaccurate is used, the shake compensation of the platform in the synthetic aperture processing system can be effectively performed.

Abstract: An integrated position mapping system and an integrated sonar mapping system both permit recording, storage and playback of audio data. Audio data is provided to the integrated sonar mapping system or the integrated position mapping system so that it may be correlated to position data or echo data. The integrated sonar mapping system includes a sonar transducer for emitting and receiving sonar signals that may be subsequently be processed to provide echo data from objects in the water which reflect sonar signals. The integrated position mapping system includes a position receiver for providing position data. A controller not only processes the data for storage, but also correlates the audio data to echo data or position data. The correlated data may therefore be retrieved for playback of the audio data and display of the position data or echo data.

Abstract: A system and method for identifying and quantifying targets within a liquid medium. A raw sidescan sonar image is collected. A region of interest is separated from the image. An image transformation is performed using an extraction algorithm. Salient image characteristics are calculated. Spurious pixels are removed from the image to obtain an extracted region of interest. Particle analysis is performed on the extracted region of interest to generate a feature vector which is presented to a neural network for classification.

Abstract: The disclosure relates to an imaging sonar for detection of objects buried in a reflecting medium, comprising a “vertical” transmit antenna and a horizontal receive antenna forming a “Mills Cross”, said transmission means enabling a vertical radiation angle producing a slightly ensonified area thereby reducing masking of the echo from said buried objects by acoustic backscatter from said reflecting medium. The invention is applicable to sonars and “sonar towfish” used for seafloor imaging and enables detection of sub-bottom objects buried in submarine sediments.

Abstract: The invention relates to a synthetic sonar antenna and more particularly to the self-calibration of such an antenna. It consists in minimizing the number of sensors of the reception antenna by fixing the reduced pitch between the sensors, imposed by the precision of the self-calibration, solely at the two ends of the antenna. According to a variant, the reduced pitch is fixed at just one end of the antenna. It makes it possible to increase the precision of the self-calibration with a smaller number of sensors than in the prior art.

Abstract: One embodiment of the system is implemented as an aircraft comprising a rotor. For example, the aircraft may be a helicopter. This embodiment also comprises an acoustic source, wherein this acoustic source comprises an acoustic signature of the aircraft. This particular embodiment also comprises an acoustic collection device affixed to the aircraft. The acoustic collection device preferably comprises an array of microphones. Finally, this embodiment also has a data processing device, such as a computer, for collecting the data detected by the microphones and processing this data. In operation, the aircraft is flown for a distance along a path while the aircraft emits acoustic energy. Then, the microphones detect the acoustic energy that is reflected off the terrain. Optionally, the detected energy may be stored as data and processed, so that noise may be reduced and a terrain image may be formed.

Abstract: A method and system for synthetic aperture sonar provide improved position estimates of a receive array as in moves through a body of water.

Abstract: A processing technique and transducer field of view architecture for use as part of an imaging sonar system to develop three-dimensional images of the space below, to the sides, and forward of a ship.

Abstract: A multi-beam acoustic transducer array system for producing color enhanced, three dimensional, high resolution images of a ship's underwater hull, wherein the acoustic transducers can be mounted in orthogonal pairs, each pair being positioned opposite from another pair within a shipping channel. The array can be utilized either in a stationary configuration within a controlled shipping lane or suspended in the water column from a mobile support vessel, with at least one array being orthogonally mounted and suspended in the water column from the mobile support vessel, wherein the mobile configuration obviates the need for multiple orthogonal arrays, for purposes of performing acquisition and imaging of a ship's hull. Each orthogonal array consists of a first transducer transmitting sonar pulses along a horizontal plane and a second transducer transmitting sonar pulses along a vertical plane, such that the two beaming sonar pulses are orthogonal, thereby providing optimal coverage.

Abstract: Method and apparatus for locating and quantifying sound sources using an array of acoustic vector probes (200). Signals received at the probes are converted to digital form and fed into a digital signal processor (400) which computes the sound pressure and the sound-intensity vector at each probe. The set of sound-intensity vectors measured by the array provides a set of directions to a sound source (100) whose approximate spatial coordinates are determined using a least-squares triangulation formula. The sound-intensity vectors also determine sound-power flow from the source. In addition sound pressure measured by the probes can be phased to form a sensitivity beam (250) for scanning a source. Sound-intensity measurements made concurrently can be used to determine the spatial coordinates of the part being scanned and the sound power radiated by that part. Results are displayed on a computer screen or other device (500) permitting an operator to interact with and control the apparatus.

Abstract: A method and system for synthetic aperture sonar provide improved position estimates of a receive array as in moves through a body of water.