Abstract: A method for estimating the height of a reflector of a vehicle, the method including a reading step, in which at least one reflection signal from the reflector of the vehicle is read at one time and the at least one reflection signal representing at least one information item in respect of a relative speed of the vehicle. Further, the method includes a specifying step, in which an estimated value for the speed of the vehicle is specified. Finally, the method includes an ascertaining step, in which an estimated value for the height of the reflector is ascertained using the relative speed of the vehicle and the estimated value for the speed of the vehicle.

Abstract: An ultrasound diagnosis apparatus includes: a two-dimensional (2D) transducer array in which a plurality of transducers that transmit/receive an ultrasound signal to/from an object are arranged in two dimensions; an analog beamformer configured to perform analog beamforming in a first direction, and perform analog beamforming in a second direction perpendicular to the first direction on signals respectively received by the plurality of transducers; and a digital beamformer configured to perform digital beamforming on the signals that are analog-beamformed in the first direction, and perform digital beamforming on the signals that are analog-beamformed in the second direction.

Abstract: An escape system used for a car being sunken into water and its ultrasonic component are illustrated. The ultrasonic component has a case and an ultrasonic module, and the escape system used for the car being sunken into water has the ultrasonic component and a mainboard. The present disclosure utilizes the property of the ultrasonic to recognize the type and thickness of obstacles which are accumulated in the ultrasonic component, and to determine whether a warning message for sweeping the obstacles should be sent, so as to maintain a sensitivity of the ultrasonic component and further to prevent the ultrasonic component from mistakenly judging that the car is sunken in water.

Abstract: In a method of using an ultrasonic sensor comprising a two-dimensional array of ultrasonic transducers, a plurality of ultrasonic signals are transmitted according to a beamforming pattern at a position of the two-dimensional array. The beamforming pattern focuses the plurality of ultrasonic signals to location above the two-dimensional array, wherein the beamforming pattern identifies ultrasonic transducers of the two-dimensional array that are activated during transmission of the ultrasonic signals, and wherein at least some ultrasonic transducers of the beamforming pattern are phase delayed with respect to other ultrasonic transducers of the beamforming pattern. At least one reflected ultrasonic signal is received at the position according to a receive pattern, wherein the receive pattern identifies at least one ultrasonic transducers of the two-dimensional array that is activated during the receiving. The transmitting and the receiving are repeated at a plurality of positions of the two-dimensional array.

Abstract: A survey system including a multibeam echo sounder having a single projector array and a single hydrophone array constructs a multi-signal message and deconstructs a corresponding multi-signal echo to substantially simultaneously perform multiple survey missions.

Abstract: A system configured to perform aligned beam merger (ABM) processing to combine multiple beamformed signals. The system may capture audio data and perform beamforming to generate beamformed audio signals corresponding to a plurality of directions. The system may apply an ABM algorithm to select a number of the beamformed audio signals, align the selected audio signals, and merge the selected audio signals to generate a distortionless output audio signal. The system may scale the selected audio signals based on relative magnitude and apply a complex correction factor to compensate for a phase error for each of the selected audio signals.

Abstract: In a method for transmit beamforming of a two-dimensional array of ultrasonic transducers, a beamforming pattern to apply to a beamforming space of the two-dimensional array of ultrasonic transducers is defined. The beamforming space includes a plurality of elements, where each element of the beamforming space corresponds to an ultrasonic transducer of the two-dimensional array of ultrasonic transducers, where the beamforming pattern identifies which ultrasonic transducers within the beamforming space are activated during a transmit operation of the two-dimensional array of ultrasonic transducers, and wherein at least some of the ultrasonic transducers that are activated are phase delayed with respect to other ultrasonic transducers that are activated. The beamforming pattern is applied to the two-dimensional array of ultrasonic transducers. A transmit operation is performed by activating the ultrasonic transducers of the beamforming space according to the beamforming pattern.

Abstract: A method for generating a composite image having an increased image pixel density by an array of ultrasonic transducers having a given spatial density is provided. The method comprises capturing a first set of pixels at an ultrasonic sensor using a first beamforming pattern, wherein the first beamforming pattern comprises a first pattern of ultrasonic transducers of the ultrasonic sensor. The method further comprises capturing a second set of pixels at the ultrasonic sensor using a second beamforming pattern, wherein the second beamforming pattern comprises a second pattern of ultrasonic transducers. The first beamforming pattern and the second beamforming pattern are different. Pixels of the second set of pixels correspond to positions between pixels of the first set of pixels. The method additionally comprises combining the first and second sets of pixels to form the composite image. An electronic device and a method of generating an image of a fingerprint are also provided.

Abstract: An ultrasonic sensor includes a two-dimensional array of ultrasonic transducers. A signal generator is configured to generate a plurality of transmit signals, wherein each transmit signal of the plurality of transmit signals has a different phase delay relative to other transmit signals of the plurality of transmit signals. A plurality of shift registers is configured to store a beamforming space including a beamforming pattern to apply to the two-dimensional array, wherein the beamforming pattern identifies a transmit signal of the plurality of transmit signals that is applied to each ultrasonic transducer of the beamforming space that is activated during a transmit operation. An array controller is configured to control activation of ultrasonic transducers during a transmit operation according to the beamforming pattern and configured to shift a position of the beamforming space within the plurality of shift registers such that the beamforming space moves within the two-dimensional array.

Abstract: Techniques are disclosed for systems and methods to provide dynamic threshold sonar systems for mobile structures. A dynamic threshold sonar system may include sonar equipment configured to capturing sonar data by receiving and converting acoustic returns into arrays of time differentiated sonar data samples, and a processor communicatively coupled to the sonar receiver. The processor may be configured to receive the sonar data samples and determine noise characteristics of the sonar data. The processor may determine a threshold for surface detection based on the noise characteristics and detect a surface, and determine a distance to the surface, based on a comparison of the sonar data to the threshold that has been determined based on the same sonar data.

Abstract: In order to avoid complicated and unpredictable effects on the wavefields emitted by air guns activated at different times, methods and systems of the current disclosure are directed to computationally designing a sequence for activating subsets of air guns in a time distributed manner that minimizes the effects of air in the water surrounding the source. The sequence may be used with discrete and continuously recorded marine surveys.

Abstract: A vehicle position display controller performs a branch determination processing of determining whether a vehicle has entered a branch road. In addition, in a case where a connecting road through which a currently traveled road is connected to a road extending in parallel with the currently traveled road lies ahead of a position of the vehicle, the vehicle position display controller performs a road shape conversion processing of subjecting the road extending in parallel to the branch determination processing on the assumption that the road extending in parallel is the branch road by making a correction of an angle between the currently traveled road and the connecting road. However, in a case where the vehicle travels at a speed equal to or greater than a predetermined speed, the vehicle position display controller does not perform the road shape conversion processing.

Abstract: A travel distance measurement device includes a transmitting antenna that is disposed in a vehicle and emits a transmission signal, as a radio wave, toward a ground surface, a receiving antenna that is disposed in the vicinity of the transmitting antenna, and receives a radio wave reflected from the ground surface and acquires a reflection signal, a distance calculator (an IQ demodulator and a phase conversion integrator) that calculates the travel distance of the vehicle on the basis of the acquired reflection signal, a gyro sensor that measures a predetermined parameter regarding curve traveling of the vehicle, and a correcting operation unit that corrects the calculated travel distance on the basis of the measured parameter.

Abstract: An embodiment of the invention relates to a method of processing seismic data comprising a plurality of traces, each trace having a source position, a receiver position and a midpoint position, each having coordinates in an inline direction and a crossline direction. The invention uses a data set comprising traces having one of the source position, the receiver position or the midpoint position having coordinates which are invariant in one of the inline or the crossline directions. A non-iterative surface related multiple attenuation algorithm is applied to the data set which assumes substantial non-variation of depth of reflectors in the same one of the inline or the crossline directions.

Abstract: Systems and methods are described herein for a variable-depth sonar. A null in the frequency response between a first and second operating frequency band is identified. A center operating frequency for each of the first and the second operating band is adjusted based on the ambient pressure. Furthermore, the velocity state of a vehicle may be calculated using periodic velocity updates. At least one transducer transmits a first signal in a first direction, and a Doppler sensor receives an echo of the first signal. The vehicle is turned in a second direction, and the at least one transducer transmits a second signal in the second direction. Using the first and the second velocity measurement, a vehicle velocity state is calculated.

Abstract: A driving assist apparatus for a vehicle is disclosed. The driving assist apparatus includes a transmitter for transmitting a transmission wave, a receiver for receiving a reflected wave, an obstacle presence determination section for detecting a presence of an obstacle in the surrounding of the vehicle based on the reflected wave, a measurement section for measuring a frequency of phase delay and advance of the reflected wave with respect to a reference signal, and a detection section for detecting the obstacle having a specific relation with the vehicle based on the presence of the obstacle determined by the obstacle presence determination section and the frequency of delay and the frequency of advance measured by the measurement section.

Abstract: A watercraft angle of attack system includes sensors having a position locator; a heading sensor; a tilt sensor; an acoustic Doppler velocity sensor that measures velocity of the boat relative to a volume of water remote from the boat so as to reduce the boat-induced disturbance of the velocity in the volume; and a processor programmed to receive real time data from the sensors; and to compute and display angle of attack of the watercraft relative to the water.

Abstract: A vehicular horn device of an existing electromagnetic type is used as a dynamic speaker so as to generate a false engine sound. The shortage of a low-pitched sound in a parametric speaker device is complemented with a false engine sound which the vehicular horn device generates. Thereby, without need of mounting a large-sized dynamic speaker such as a woofer in a vehicle, a false engine sound is generated so as to model for a real engine sound. In addition, as the vehicle approaches a pedestrian, a sound tone of the false engine sound which the pedestrian hears changes, enabling the pedestrian to easily notice the approach or presence of the vehicle.

Abstract: A vehicle presence notification apparatus uses several ultrasonic transducer devices to generate a notice sound by emitting an ultrasonic wave in mid air based on an ultrasonic signal modulated according to an audible sound. At least one of the speaker-use ultrasonic transducer devices is a two-way transducer device that is enabled to perform not only transmission but also reception of an ultrasonic wave. When a vehicle velocity is equal to or greater than a predetermined value, the two-way transducer device is caused to function as an ultrasonic sensor. Thus, even when the generation of any notice sound is unnecessary due to the vehicle velocity being fast, the vehicle presence notification apparatus can be used as an ultrasonic sensor to measure a distance with an obstacle outside of the vehicle.

Abstract: A vehicle presence notification apparatus generates a notice sound by emitting an ultrasonic wave in mid air based on an ultrasonic signal modulated according to an audible sound. During proceeding in mid air, the modulated ultrasonic wave is self-demodulating to become an audible sound. The audible sound posterior to the self-demodulation has a significant directionality like the ultrasonic wave. The notice sound is thus conveyed mainly to a pedestrian who is present in a dangerous area range where a danger needs to be taught. In addition, the vehicle presence notification apparatus includes a sensor-use ultrasonic transducer device having a transducers. The transducer device serves as a vehicle velocity sensor by transmitting an ultrasonic wave towards a road surface based on an ultrasonic wave signal or modulated ultrasonic wave, thereby enabling the vehicle presence notification apparatus to acquire vehicle velocity information by itself.

Abstract: The invention relates to a method of determining an estimated speed of an aircraft relative to ground being overflown by the aircraft, in which use is made of the sum of an acceleration measurement of the aircraft plus a difference value, the difference value being obtained from observation data or signals relating to a region of the ground.

Abstract: A system is disclosed that enables the use of an incomplete SONAR array matrix in a correlation SONAR system. An improvement is achieved through the generation of a correlation-array model matrix of hydrophone correlations, based on an independent estimate of the ship's velocity, such as from an inertial navigator. Meanwhile, estimates of the missing values are generated based on one or more values from the model matrix, an interpolation of values from the SONAR array matrix itself, or some combination thereof. Regardless of how the missing values are generated, the model matrix provides a basis for comparison with the SONAR array matrix, which is populated with the estimated values, wherein subsequent comparisons are made between successive iterations of the model matrix and the SONAR array matrix. By applying the disclosed technique, a correlation SONAR system with incomplete data is able to continue working, and in the presence of a greater number of hydrophone failures than before.

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 method is provided for improving horizontal spatial resolution of a flow field in compact jet-like current features so as to quantify the axial velocity in the cross section of a compact jet using an Acoustic Doppler Current Profiler (ADCP). The ADCP is a four-beam, Janus-type ADCP having beams aligned so that each of the beams is at an angle of about 20° to 30° to vertical and at 45° to the fore and aft axis of the vessel, such that two beams point at 45° to forward and two pointing 45° to aft. The measurements from each range bin of the aft-facing beams are combined with the previously measured samples from the corresponding forward-facing beams at the same position along the vessel track.

Abstract: A method and a system for measuring the velocity of a vessel relative to the bottom using a velocity measuring correlation sonar are disclosed. The present invention provides a new theoretical expression for the bottom medium sonar array temporal and spatial correlation function. The velocity of the vessel relative to the bottom is derived by fitting experimental data to a theoretical function. The bottom medium sonar array temporal and spatial correlation function of the present invention is succinctly expressed in zero-rank Bessel function, and well coincided with experiments. The function is applicable not only to far field region, i.e. planar wave region, but also to Fraunhofer region, i.e. spherical wave region. Transmit transducers and receive transducers are multistatic in the velocity measuring correlation sonar of the present invention, so the transmit beam width and the receive beam width can be selected reasonably.

Abstract: A method of finding a vertical velocity of a vehicle by first forming two cost functions from three pulse return times. An independently determined approximate vertical velocity and a Fletcher-Powell estimation technique are used on the first cost function, to select a minimum velocity of the first cost function. The selected minimum velocity, two calculated velocities from the selected minimum velocity, and a Fletcher-Powell estimation technique are used on the second cost function, to select a minimum velocity of the second cost function. The selected minimum velocity of the second cost function is taken as the vertical velocity of the vehicle.

Abstract: A detecting apparatus of vehicle speed including detecting means for emitting an electromagnetic wave or an ultrasonic wave to a road surface and detecting traveling speed of a vehicle from the Doppler effect produced in a reflected wave thereof, a transmitting circuit for sending information about the traveling speed detected by the detecting means by radio, a power generation mechanism for generating power by vibration produced in the vehicle, and a charging circuit for charging a charging type battery by an output voltage of the power generation mechanism.

Abstract: A parking aid system for a vehicle includes a device that measures the instantaneous distance of a vehicle part from an obstacle located in its path and generates at least one output signal indicative of the measured distance, as well as a device capable of issuing warning signals. An evaluating unit is connected between the measuring device and the warning device. The evaluating device dynamically determines, as a function of vehicle speed, an instantaneous distance limit value, compares the measured distance value with the respective distance limit value and activates the warning device when the measured distance value is smaller than the respective distance limit value to alert the driver of the vehicle to the presence of the obstacle. The distance limit value may be determined by adding a first distance value independent of the speed of the vehicle and a second distance value linearly proportional to the speed of movement of the vehicle.

Abstract: A process for making it possible to detect moving objects by an active sonar operating by the Dopper effect. The process uses, as a transmission signal, a burst of N pulses encoded so as to present a spectrum having a comb-of-lines structure. In this way, the “signal/reverberation” ratio of the useful signal intensity to the reverberated intensity is increased, thereby increasing the efficiency of the sonar. The process allows objects moving in a reverberating transmission medium to be detected more easily.

Abstract: A method and system are provided to estimate a ship's velocity. Two ship sonar returns from two different directions are selected. Each return includes volume reverberation data and bottom reverberation data. Doppler shift for each of the two returns based on the volume reverberation data is determined as a basis for estimating ship velocity relative to the water. Doppler shift for each of the two returns based on the bottom reverberation data is determined as a basis for estimating ship velocity relative to the ground.

Abstract: An acoustic transducer array in which the transducer elements project a plurality of acoustic beams which are not coplanar. In a first embodiment, a cylindrical transducer array housing has each of four transducer elements skewed at an angle relative to the longitudinal axis of the housing. Each acoustic beam formed by the array lies in a unique plane (e.g., in a "pinwheel" configuration), thereby effectively eliminating overlap of the beams throughout the entire profiling range of the array. In another aspect of the invention, acoustic damping material is incorporated throughout selected portions of the transducer housing to mitigate the effects of echoes and undesirable acoustic propagation within the array.

Abstract: An automated method for the manufacture of a coil spring assembly including inserting coil springs having predetermined multiple spring rates into respective individual pockets of a continuous pocket strip in a predetermined order. The predetermined multiple spring rates of at least one coil spring may differ from that of the other coil springs, and each of the multi-rate coils has at least two different spring rates. One or more wires having a substantially uniform thickness are coiled to form the multiple rate coil springs before insertion into the continuous pocket strip. The wire is preferably coiled to produce a coil spring having at least two different diameters and at least two different pitches. The method also includes cutting the spring-filled strip into one or more desired lengths, placing at least two spring-filled lengths adjacent to each other; and attaching adjacent lengths together. A coil spring assembly may thus be provided with one or more firmness zones.

Abstract: An acoustic array transducer capable of forming narrow dispersion, broadband or narrowband acoustic beam sets in two dimensions with a minimum aperture size. Concurrent yet independent electrical interfacing with array transducer elements allows simultaneous formation of multiple transmit and receive beams inclined within two planar orientations normal to the array face, while requiring a minimum amount of supporting circuitry. A method of economically and accurately fabricating the aforementioned transducer array by incrementally dicing bonded layers of solid discs of transducer materials being rigidly held together is also disclosed.

Abstract: A sonar antenna with transducers symmetrically distributed along an axis (fore/aft axis) and a perpendicular axis (starboard/port axis) in a plane on a circular base. Placement and polarities of the transducers, along with a phase and sequence of feeding two distinct frequencies to the transducers create four emission lobes inclined at 30 degrees one emission lobe with respect to each axis. Summation of reception signals (echos) from selected transducers based on frequency and accounting for time allow for the determination of fore/aft and starboard/port reception signals from which a velocity of the antenna or a vehicle attached to the antenna can be calculated.

Abstract: The apparatus has a signal processor for determining the ground speed of a motor vehicle on the basis of the frequency of a wave transmitted from a transmitter and the frequency of the wave reflected by the ground surface and received by a receiver. The signal processor includes a relationship obtaining device for obtaining a relationship between an estimated vehicle speed obtained on the basis of the speed of a vehicle wheel, and a provisional speed determined on the basis of the frequencies of the transmitted and reflected waves, when the vehicle is in a steady running state in which the estimated vehicle speed accurately represents the actual vehicle speed. The signal processor determines the final vehicle speed on the basis of the obtained relationship.

Abstract: An ultrasonic measuring system for a vehicle is composed of first and second ultrasonic transducing assemblies TR1 and TR2. Each transducing assembly TR1, TR2 has three ultrasonic transducers TR11, TR12, TR13, TR21, TR22, TR23 which are separated from each other at an angle of 120 degrees in a horizontal plane about axis disposed at a front and a rear of the vehicle, respectively. Each transducer transmits ultrasonic waves to a road surface at a predefined down-angle relative to the road surface and receives reflected waves from the road surface. Each of the transducers TR21, TR22, TR23 transmits ultrasonic waves to the road surface and receiving reflected waves from the road surface in an opposite direction to a corresponding one of the transducers TR11, TR12, TR13.

Abstract: A Doppler-effect speed detecting apparatus for detecting a ground speed of a vehicle, including a transmitter for transmitting a wave towards the ground surface, a receiver for receiving the wave reflected by the ground surface, and an output device for producing an output indicative of the ground speed according to the frequencies of the transmitted and reflected waves. The apparatus further includes a device for determining presence or absence of abnormality relating to the output of the output device, on the basis of an output level of the receiver as well as a speed difference between the ground speed obtained by the output device and an estimated vehicle speed which is obtained on the basis of rotating speeds of the vehicle wheels.

Abstract: In a correlation device, a system and method for measuring velocities using a single coded pulse generator. The correlation device may also include maximum likelihood estimation techniques for processing the echo signals received from a plurality of transducers. The presently preferred embodiment of the device is as a current profiler having a bottom tracking capability for providing vessel velocity.

Abstract: A warning device is provided for use in an electric vehicle which includes a frame member and ground engaging wheels operative mounted relative to the frame member. An electric motor is operatively connected to the frame member and the ground engaging wheels for supplying rotational motion to the ground engaging wheels. A switch member is provided for selectively energizing the electric motor. An indicator member is provided for indicating to an operator that the electric vehicle has completed a preparing to start operation. The switch member may be a switch for operatively connecting the electric motor to a source of power. The indicator member may provide a visual display or an audible sound for warning the operator.

Abstract: An apparatus for detecting a vehicle ground speed, including a transmitter for transmitting a wave towards a ground surface, and a receiver for receiving a portion of the transmitted wave reflected by the ground surface. The apparatus produces an output indicative of the vehicle ground speed, according to a Doppler effect on the basis of the frequencies of the transmitted wave and the reflected wave, and further includes a device for changing the frequency of the transmitted wave so that the sensitivity of the receiver is held within a predetermined optimum range. The device is adapted to restrict or inhibit a change in the frequency of the transmitted wave due to deterioration of the condition of the ground surface which causes the receiver sensitivity to be lowered.

Abstract: A Doppler-effect vehicle ground-speed detecting apparatus having a transmitter fixed to a vehicle body and transmitting a wave toward a road surface on which the vehicle is running, a receiver fixed to the body and receiving a portion of the wave reflected by the road surface, and a ground-speed determining device for determining a ground-speed of the vehicle relative to the road surface, on the basis of a transmitting frequency of the wave as transmitted by the transmitter and a receiving frequency of the wave as received by the receiver. The ground-speed determining device determines the ground-speed of the vehicle, on the basis of a parameter which changes with an angle of the vehicle body relative to the road surface in a plane parallel to a running direction of the vehicle and perpendicular to the road surface, as well as on the basis of a difference between the transmitting and receiving frequencies.

Abstract: An ultrasonic ground speedometer utilizing Doppler effect of ultrasonic waves comprises an ultrasonic transmitter for outputting an ultrasonic wave at an emitting angle against a road surface, an ultrasonic receiver for receiving a reflected ultrasonic wave caused by reflection of the output ultrasonic wave from the road surface, a signal processor for deriving a Doppler shift frequency between the frequencies of the output ultrasonic wave from the ultrasonic transmitter and the reflected ultrasonic wave received by the ultrasonic receiver, a first arithmetic circuit for deriving the angle difference between the emitting angle and the reception angle defined between the road surface and the propagation direction of the reflected ultrasonic wave received by the receiver, on the basis of the Doppler shift frequency, and a calculating circuit for calculating a ground speed of the vehicle, on the basis of both the Doppler shift frequency and the angle difference.

Abstract: A combined speed and depth transducer adapted to be mounted flush in the hull of a ship. An acoustic depth transducer is mounted piggyback on top of an acoustic speed transducer within a single housing. A base plate is sandwiched between the depth transducer and the speed transducer. The dimensions and frequency of transmission of the transducers are selected to prevent ringing in one transducer that may be caused by the acoustic wave of the other transducer. The base plate 40 is constructed to damp the acoustic wave transmitted by the speed transducer and be transparent to the acoustic wave transmitted by the depth transducer. Having the depth and speed transducers mounted within a common housing, and flush with the hull of the ship, provides the advantage of having to make only a single hole in the hull as well as having a low drag.

Abstract: A system measures the velocity of a moving body such as a ship and a water body. The system uses a first apparatus which measures the speed of a moving body by detecting a phase difference between a reference signal and echo signals resulting from a transmitted ultrasonic signal, implementing a Fourier transformation on the phase difference data obtained, computing the speed of the ship with respect to the water based on the Fourier spectrum data, and, computing the velocity of a water current based on the speed of the ship with respect to the ground and the speed of the ship with respect to the water obtained.

Abstract: An ultrasonic ground speedometer utilizing Doppler effect comprises an ultrasonic transmitter for outputting an ultrasonic wave at a predetermined angle against a road surface, an ultrasonic receiver for receiving a reflected ultrasonic wave caused by reflection of the output ultrasonic wave from a road surface, an arithmetic circuit for deriving ground speed from Doppler shift between the output ultrasonic wave and the reflected ultrasonic wave. The ultrasonic ground speedometer also includes an output frequency control circuit for controlling the output ultrasonic wave frequency in such a manner as to keep the reflected ultrasonic wave frequency to a constant value in response to changes in ground speed. An amplification degree control circuit is also included for controlling the amplitude of the output ultrasonic wave to keep a substantially constant output intensity of the output ultrasonic wave over an output ultrasonic wave frequency range controlled by the output frequency control circuit.

Abstract: An ultrasonic ground speedometer utilizing Doppler effect comprises an ultrasonic transmitter for outputting an ultrasonic wave at a predetermined angle against a road surface, an ultrasonic receiver for receiving a reflected ultrasonic wave caused by reflection of the output ultrasonic wave from a road surface, an arithmetic circuit for deriving ground speed from Doppler shift between the output ultrasonic wave and the reflected ultrasonic wave. The ultrasonic ground speedometer also includes an output frequency control circuit for controlling the output ultrasonic wave frequency in such a manner as to keep the reflected ultrasonic wave frequency to a constant value in response to changes in ground speed. An amplification degree control circuit is also included for controlling the amplitude of the output ultrasonic wave to keep a substantially constant output intensity of the output ultrasonic wave over an output ultrasonic wave frequency range controlled by the output frequency control circuit.

Abstract: The velocity of a vessel is determined in real time by a doppler sonar sym providing acoustic beams wherein received beams provide a plurality of bins or returns from various depth segments. The frequency shift with respect to at least two different bins is determined. The velocity of the vessel with respect to each bin is determined according to the phase shift of the respective bin. The vessel velocity is determined as an average of the determined velocities of the bins along the acoustic beam. The acoustic beams are paired to form beam pairs wherein each bin in one beam of the beam pair has a corresponding bin in the other beam of the beam pair. The phase shifts of the corresponding bins are used to determine a relative frequency shift for the corresponding bins. This determination is made along the length of the beams of the beam pair and averaged. The averaged resolved ship doppler profiler velocity when compared to inertial velocities determines water current velocities.

Abstract: An ultrasonic ground speedometer utilizing Doppler effect comprises an ultrasonic transmitter for outputting an ultrasonic wave having a particular wavelength at a predetermined angle against a road surface, an ultrasonic receiver for receiving a reflected ultrasonic wave caused by reflection of the output ultrasonic wave from the road surface, and a signal processor for deriving ground speed from Doppler shift between the output ultrasonic wave and the reflected ultrasonic wave. The particular wavelength is set to a value within a range of 2.6 mm through 3.4 mm to assure the highest possible S/N ratio for the Doppler shift signal obtained from the signal processor.

Abstract: A method for the determination of in-line and cross-line components of water velocity relative to a vessel heading on a chosen line, which method comprises the steps of:(a) generating electronic pulses and relaying these to a Doppler-Sonar transducer aligned fore and aft with respect to the keel of the vessel,(b) radiating pulses from the Doppler-Sonar transducer in a number of directions at an angle .theta. relative to the horizontal to a layer of water below but near to the surface of the water, and, simultaneously,(c) radiating pulses from the Doppler-Sonar transducer in a number of directions at an angle .alpha. relative to the horizontal, and greater than .theta.

Abstract: A system and method for forming acoustic beams is disclosed. One embodiment is an acoustic system configured to generate a plurality of beams non-orthogonal to a transducer array simultaneously with a vertical acoustic beam orthogonal to the array. The acoustic system includes a plurality of transducer elements arranged to form a two-dimensional array and electrically connected into rows in a first dimension and columns in a second dimension.