Abstract: An apparatus and method for relating echoes from a surface or object produced by irradiation, such as by sonar or radar, from different grazing angles according to the relationship: f s = cf x 2 ? cos ? ? ? where fx is the spatial frequency corresponding to the size of the surface or object, ? the grazing angle, and fs the temporal frequency. In this manner one can relate to one another echoes from the same surface or object generated at different grazing angles, permitting good correlation between the echoes.

Abstract: A downscan imaging sonar utilizes a linear transducer element to provide improved images of the sea floor and other objects in the water column beneath a vessel. A transducer array may include a plurality of transducer elements and each one of the plurality of transducer elements may include a substantially rectangular shape configured to produce a sonar beam having a beamwidth in a direction parallel to longitudinal length of the transducer elements that is significantly less than a beamwidth of the sonar beam in a direction perpendicular to the longitudinal length of the transducer elements. The plurality of transducer elements may be positioned such that longitudinal lengths of at least two of the plurality of transducer elements are parallel to each other. The plurality of transducer elements may also include at least a first linear transducer element, a second linear transducer element and a third linear transducer element.

Abstract: Technologies are provided to recover motion, position, or navigation data of underwater sensors using bathymetry data. A method includes iteratively fitting data obtained by an underwater sensor from interactions between acoustic signals and an underwater floor, and deriving at least one of motion, position, or navigation data of the underwater sensor from the fitting. A standalone sonar can use the methods, systems, apparatuses, and computer programs to realize the derivation of motion, position, or navigation data without a position or motion sensor.

Abstract: The systems and methods described herein relate to systems and methods for synthetic aperture sonar (SAS) or radar including the use of orthogonal signals with SAS.

Abstract: The systems and methods described herein relate to systems and methods for synthetic aperture sonar (SAS) or radar including high-frequency holographic navigation.

Abstract: The systems and methods described herein relate to systems and methods for synthetic aperture sonar (SAS) having multiple transmitters and generating orthogonal pinging sequences configured to enhance performance.

Abstract: The systems and methods described herein relate to systems and methods for synthetic aperture sonar (SAS) or radar including overpinging with multiple SAS transmitters.

Abstract: The systems and methods described herein relate to systems and methods for synthetic aperture sonar (SAS) or radar including simultaneous localization and mapping (SLAM) for holographic navigation.

Abstract: A method and apparatus for determining the topography of a seafloor includes providing a vessel with a multibeam sonar device which transmits first pulses of first signals, and a pair of sidescan sonar devices, which transmit second pulses of second signals, spaced apart rearwardly from the multibeam sonar device on the vessel. The first and second pulses produced by the multibeam sonar device and the sidescan sonar devices, respectively, are interleaved, and the time duration between each second pulse and the next following first pulse, and between each first pulse and the next following one of the first and second pulses is determined as a function of the maximum time-of-flight of the first signals of one of the previous first pulses from the time of transmission thereof to the time of reception of the backscattered first signals.

Abstract: A downscan imaging sonar utilizes a linear transducer element to provide improved images of the sea floor and other objects in the water column beneath a vessel. A transducer array may include a plurality of transducer elements and each one of the plurality of transducer elements may include a substantially rectangular shape configured to produce a sonar beam having a beamwidth in a direction parallel to longitudinal length of the transducer elements that is significantly less than a beamwidth of the sonar beam in a direction perpendicular to the longitudinal length of the transducer elements. The plurality of transducer elements may be positioned such that longitudinal lengths of at least two of the plurality of transducer elements are parallel to each other. The plurality of transducer elements may also include at least a first linear transducer element, a second linear transducer element and a third linear transducer element.

Abstract: A method for providing a combined linear and circular downscan sonar display may include receiving linear downscan sonar data from a linear downscan transducer, receiving conical downscan sonar data from a circular downscan transducer, and combining the linear downscan sonar data and the conical downscan sonar data to produce combined downscan sonar data. A corresponding computer program product and apparatus are also provided.

Abstract: A method for measuring a profile of the ground involves using a transmitting arrangement, which is attached to a watercraft, for the directed emission of sound signals into an underwater area and a receiving arrangement having at least two transducers for receiving sound waves reflected by the profile of the ground.

Abstract: This disclosure provides an underwater detection device, which includes a first generator for generating a first transmission signal, a second generator for generating a second transmission signal having a longer pulse width than that of the first transmission signal, an output unit for outputting the transmission signals generated by the first and second generators to a transducer for transmitting underwater ultrasonic waves based on the first and second transmission signals, respectively, receiving the reflection waves caused by the ultrasonic waves, respectively, and converting the reflection waves into a first reception signal and a second reception signal, respectively, an underwater detector for detecting at least one of a presence of a target object and a water bottom depth based on the first reception signal, and a bottom sediment discriminator for discriminating a water bottom sediment type based on the second reception signal.

Abstract: This disclosure provides a detection device, which includes a transceiver for transmitting a transmission signal and receiving an echo caused by the transmission signal to output a reception signal according to an intensity of the echo, the reception signal in one measurement including one or more reception signals, and an interference detector for detecting an interference signal from the one or more reception signals. The interference detector performs a switching operation of switching interference detection processing between first interference detection processing and second interference detection processing that has a higher interference detection sensitivity than in the first interference detection processing, according to the number of the reception signals detected as the interference signals.

Abstract: A method for measuring a contour of the ground by means of a transmitting arrangement for the directed emission of sound signals and by means of a receiving arrangement including at least two transducers for receiving the sound signals reflected from the contour of the ground. Sound signals are emitted consecutively using a plurality of N soundings from predetermined positions P1, P2, P3, P4, . . . , PN having different aspect angles ?N in relation to and distances rN from the contour of the ground. A phase difference, the path differences resulting therefrom, the corresponding angles of incidence, and the coordinates of incidence are ascertained from the receive signals of the transducers for a plurality of sampling times and for the N soundings. Afterwards, the data density is ascertained within a predefined range containing the coordinate of incidence.

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 computer based system and method for determining if a change detection sonar contact in change detection side scan sonar imagery matches a historical contact of the same geospatial location.

Abstract: A method including carrying out, by means of an underwater vehicle moving above a given zone of the sea bed, observations on the basis of which the positions of elements of relief and of objects present on the bed are estimated. These observations are associated with fictitious objects, tied together by fictitious elastic links so as to constitute a fictitious elastic network. The network is in equilibrium as long as no action is exerted on one or the other of the fictitious objects constituting the network. The objects then occupy fixed positions, positions assigned to the corresponding observations. On the other hand, when two observations assumed to correspond to one and the same object are fused into a single observation, the two corresponding fictitious objects are brought closer together. This bringing closer together induces the appearance of stresses in the fictitious elastic network.

Abstract: System and methods for compensating a depth signal for a depth finder of a boat. In one embodiment, a compensation system is implemented between the depth finder and a transducer mounted on the boat. The compensation system receives a depth signal (i.e., a plurality of electrical impulses) from the transducer that directs sound waves toward the bottom of a body of water. The compensation system also monitors a change in elevation of the transducer, such as due to waves rocking the boat. The compensation system then compensates the depth signal based on the change in elevation, and provides the compensated depth signal to the depth finder.

Abstract: An underwater detection device for detecting underwater by transmission and reception of an ultrasonic signal is provided. The device includes a transmission module for transmitting the ultrasonic signal underwater, a reception module for receiving an echo signal of the transmitted ultrasonic signal, a bottom detection module for detecting a bottom based on the echo signal from the bottom, a bottom-sediment determination module for calculating probabilities of the bottom sediment on how much the bottom sediment contains each of predetermined bottom sediment types based on the echo signal and a bottom-sediment display module for displaying a texture representing each of the bottom sediment types below the bottom being displayed based on the probabilities.

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: Method and apparatus for detecting and locating underwater obstacles in the path of a ship or boat. The apparatus includes a pulsed wide-angle sonar projector (100) controlled by a digital signal processor (400) that emits sound pulses at frequencies of 30 kHz and less that can penetrate sediment-laden water hundreds of meters or more ahead of the ship or boat. The projector generates echoes from submerged objects. A vector sound-intensity probe (200) receives the echoes and transmits them to the digital signal processor. The digital signal processor determines the location of submerged obstacles ahead of the ship or boat from the echoes received by the probe. This information is displayed on an output device (500). The sonar projector and vector sound-intensity probe are contained separately in streamlined housings aimed in the forward direction under the bow of the ship or boat. The processor, output device and other electronics are located on board the ship or boat.

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: The present invention relates to a system and method for detecting and measuring phenomena relating to altimetric variations in the seafloor. The system (100) according to the present invention comprise an autonomous submarine vehicle (101) equipped with at least one interferometric sonar sensor (102) for sending an acoustic signal towards the seafloor and acquiring the image of the seafloor generated by the reflection of said acoustic signal sent, and is characterized in that it comprises a plurality of elements (103, 103?) reflecting the sound waves firmly fixed to the seafloor so as to outline a reference path for the passage of the autonomous submarine vehicle (101).

Abstract: A method and system are described that can be used for combining two sources of position and orientation (pose) information where the information from one source is correlated with the information from the other and the sources produce information at differing rates. For example, the method and system allow for estimating position and orientation (pose) of an underwater vehicle relative to underwater structures by combining pose information computed from a 3D imaging sonar with pose information from a vehicle navigation system. To combine the information from the two sources, a determination is made as to whether to generate a forward prediction of the pose estimate of one of the sources relative to the other, and generating the forward prediction if needed. An updated pose of the underwater vehicle is determined based on the fused pose estimate, and which is used for vehicle guidance and control.

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: 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: 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: An active sonar system and associated method combine signals from a plurality of receive beams in order to reduce a noise in a reference one of the signals from the plurality of receive beams.

Abstract: A method for pre-determining an underwater objects GPS position using a forward scan sonar unit linked to a boat trolling motor, 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 forward scan sonar transducer and compass mounted on a 360 degree movable mechanism such as a trolling motor unit, and formulates the objects position based on the distance and heading of the object in relation to the boats current GPS position.

Abstract: An apparatus and method for ocular surgery includes a delivery system for generating and guiding a surgical laser beam to a focal point on a target surface in a treatment area of an eye. A detector is coupled to the beam path of the surgical laser to create a three-dimensional image of the target surface, and a computer morphs this three-dimensional image into a two-dimensional image. Operationally, the computer then uses the two-dimensional image to position and move the focal point in the treatment area for surgery.

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: Frontal sonar for observing the seafloor, characterized in that it includes: elements for insonifying a seafloor area divided into M sectors, able to perform a characteristic insonification of each sector of the area during an operation recurrence of the sonar; and receiving elements including a physical antenna consisting of an array of K transducers, the antenna being lacunar and thus ambiguous, so that it defines N image lobes, and in that each of the characteristically insonified sector is associated with a single image lobe defined by the antenna, so that the antenna ambiguity is removed.

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: Sonar imaging data is reduced by assigning partially reflective and/or opaque two dimensional areas for each data point to a series of planes. The reflectivity and/or transmission of light from the areas is calculated and used to construct an image.

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: Sonar imaging data is reduced by assigning partially reflective and/or opaque two dimensional areas for each data point to a series of planes. The reflectivity and/or transmission of light from the areas is calculated and used to construct an image.

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 drift 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 digital mapping display and related system for fishing, and other applications.

Abstract: A downscan imaging sonar utilizes a linear transducer element to provide improved images of the sea floor and other objects in the water column beneath a vessel. A transducer array may include a plurality of transducer elements and each one of the plurality of transducer elements may include a substantially rectangular shape configured to produce a sonar beam having a beamwidth in a direction parallel to longitudinal length of the transducer elements that is significantly less than a beamwidth of the sonar beam in a direction perpendicular to the longitudinal length of the transducer elements. The plurality of transducer elements may be positioned such that longitudinal lengths of at least two of the plurality of transducer elements are parallel to each other. The plurality of transducer elements may also include at least a first linear transducer element, a second linear transducer element and a third linear transducer element.

Abstract: A method for providing a combined linear and circular downscan sonar display may include receiving linear downscan sonar data from a linear downscan transducer, receiving conical downscan sonar data from a circular downscan transducer, and combining the linear downscan sonar data and the conical downscan sonar data to produce combined downscan sonar data. A corresponding computer program product and apparatus are also provided.

Abstract: A method and device for displaying an underwater detection image is provided, in which an ultrasonic signal having a predetermined beam width is periodically transmitted underwater, receives a signal reflected on a detection target object which moves underwater, generates information on the detection target object based on the received signal, and displays the information on a display module. The method includes periodically detecting the detection target object and a position thereof based on the received signal, coupling the same detection target objects by associating the same based on the detection target object and the position periodically detected, and associating a displacement symbol corresponding to a change in a position of the detection target object with the coupled detection target object, and displaying the displacement symbol at the detected position of the detection target object at least on a two-dimensional position coordinates displayed in the display module.

Abstract: A system for measuring electrical resistivity survey checks a border of bedrock or a thickness of a sedimentary layer in a riverbed of a river or lake within a short time. A method for analysis of an underground structure of a riverbed using the same is also provided. The system for streamer electric resistivity survey using a survey boat comprises a streamer cable connected to the survey boat and having a plurality of electrodes attached thereto; a multi-channel resistivity meter loaded on the survey boat to measure electric resistivity from the plurality of electrodes; a first RTK GPS (Real Time Kinematic Global Positioning System) loaded on the survey boat to measure a position of the survey boat in real time; and a second RTK GPS installed to a tail of the streamer cable to measure a position of the tail in real time.

Abstract: A method and associated vessel for transferring liquids from offshore tankers to an onshore storage facility. The system utilizes a flexible pipe that is heavier than the water it displaces, such that the flexible pipe sinks to the sea floor even when empty. The high weight and relatively small profile of the flexible pipe avoids the need for anchoring the pipe to the sea floor. The flexible pipe has a bending radius of no greater than five feet, such that it can be wound onto spools onboard the vessel, and can be rapidly deployed, retrieved, and reused in another location. The vessel containing the spools of flexible pipe is dynamic positioning capable, and contains the equipment required to establish a position onshore to receive the liquid being transferred; means to deploy, retrieve, and repair the flexible pipe; and means to receive liquid from a tanker vessel and pump that liquid through the flexible pipe to the onshore storage facility.

Abstract: A computer-implemented method, system, computer-readable medium, and apparatus for identifying a boundary of a cluster in a bitmap, the bitmap having at least one initially set bit, for applying an expansion shape to each of the initially set bits in the bitmap and identifying vertex bits on the boundary of the cluster formed by at least one expansion shape.

Abstract: A device and method for determining bottom sediment is provided. The method includes transmitting a pulse of a pulse width corresponding to a water-bottom depth, extracting a series of amplitude data of water-bottom echo signals from predetermined signals among the water-bottom echo signals received by the transducer at a predetermined time interval, normalizing the extracted series of amplitude data after TVG-processed, calculating two or more feature quantities based on the normalized series of amplitude data in each of segments of the normalized series of amplitude data, and a value corresponding to the water-bottom depth, and generating bottom-sediment classification information indicating the bottom sediment based on the two or more feature quantities.

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: Acoustic apparatus and method for detecting and identifying near-surface buried objects using a non-contact array of ultrasonic vibrometers (200) each vibrometer having a focused beam in air (400) pointing vertically at the ground. Also there is a low-frequency loudspeaker (60). Both are connected to a digital signal processor (40). The loudspeaker emits continuous sound that penetrates the ground and generates echoes from a buried object, creating seismic vibrations (350) at the surface (150). The vibrometers emit pulses of focused ultrasound with a known depth of field (650) and receive echo pulses (770) from the seismic vibrations. The pulses occur at a much faster rate than the frequency of the seismic vibrations, typically a few thousand times faster, thus permitting the processor to compute the motion and frequency content of the seismic vibrations. This data from the array determines the shape and frequency response of near-surface buried objects which are shown on a display device.

Abstract: A method and apparatus for determining the topography of a seafloor comprises providing a vessel (1) with a multibeam sonar device (5) and a pair of sidescan sonar devices (10) spaced apart rearwardly from the multibeam sonar device (5) on the vessel (2). The multibeam sonar device (5) transmits first pulses of first signals directly downwardly towards the seafloor with a wide fan angle (?) in a first vertical transverse plane (7). The sidescan sonar devices (10) direct second pulses of second signals of similar wavelength to those of the first signals downwardly and sidewardly outwardly of the vessel (2) with a wide fan angle (?) in a second vertical transverse plane (11).