Abstract: A method for determining Doppler shifts and reflectivity data based on wavelet based sodars. Initially, a high powered sodar pulse of sound is transmitted from an antenna into the atmosphere. This pulse of sound consists of a string of concatenated wavelets. The reflected portion of this transmitted pulse is received, amplified and digitized as a string of samples of time correspond to the range of transmission. After sampling for a short time interval to cover the maximum range of sound, the sampled time series is divided into range gates. For Doppler shifts the power spectrum of the sampled time series is calculated and a peak surrounding the frequency of the transmitted sound is observed. From this peak the direction and velocity of the atmosphere at a given attitude is derived. To accurately arrive at a better velocity resolution, replication is used with wavelet coefficients and an inverse wavelet transform.

Abstract: A short ring is mounted onto a back part of a housing of an ultrasonic sensor so that the short ring is coaxial with the housing. The width of the short ring along the axial direction of the housing is set such that it shields the back part of the housing including a transformer of a processor. The short ring is made up of an excellent metal conductor and is coaxial with the coils of the transformer.

Abstract: An ultrasonic angular measurement system is disclosed. The system is comprised of three parts, a control box used to collect and process data, an ultrasonic transducer, and a reflector block. The reflector block is configured so that it intercepts transmitted pulses received over a wide range of angles back to the transducer. All the components are self contained within a transportable housing which is attached to the aircraft deck during measurement of tip-off angle. The range of angle measurement is permitted because of the use of the unique reflector block which comprises a plurality of reflector segments for reflecting ultrasonic pulses transmitted at various ranges of angles.

Abstract: A personal direction finding apparatus for determining the direction to be followed in order to reach a predetermined spot which includes a headset provided with two earphones and a circuit for generating a track error signal. The circuit includes a compass supported on the headset for outputting a heading signal corresponding to the heading of the direction of travel, a receiver for a position location and navigation system outputting a signal for the heading to be followed via one output, and a track error computing circuit.

Abstract: A sludge blanket level is determined in a waste water treatment clarifier using sonic pulse reflections. Additionally, using similar techniques, the clarity of the waste water is determined. A sonic pulse is directed into the waste water. Echos are generated as the pulse encounters the impedance mismatches indicative of changes in the density of the water. The echos are compensated for attenuation as a function of travel time through the water, energy lost due to prior peak reflections, and are processed to remove random signals using correlation techniques. A sludge blanket is selected from the compensated echo signal as a function of the size and location of echo peaks. Additionally, the clarity is determined as a flnction of the area under the echo signal between two points corresponding to predefined levels in the clarifier tank.

Abstract: In a method for detecting objects hidden underground, a plurality of electromechanical transducers including at least one electroacoustic pressure wave generator and at least one acoustoelectric sensor are disposed above a ground structure. Locations of the transducers relative to one another are determined. The pressure wave generator is energized to produce an outgoing pressure wave which is transmitted into the ground structure. Incoming pressure waves reflected by underground surfaces in response to the outgoing pressure wave are sensed and analyzed to determine three-dimensional shapes of underground objects disposed in the ground structure.

Abstract: A method of bearing estimation comprising quadrature digital filtering of event observations, constructing a plurality of observation matrices each centered on a time-frequency interval, determining for each observation matrix a parameter such as degree of polarization, linearity of particle motion, degree of dyadicy, or signal-to-noise ratio, choosing observation matrices most likely to produce a set of best available bearing estimates, and estimating a bearing for each observation matrix of the chosen set.

Abstract: A driving force control apparatus for moving a vehicle by a desired distance includes an input section for input a desired move distance, a throttle controller section for setting a throttle actuator of the vehicle at an opening degree, an actual moved distance detecting section for detecting an actual moved distance of the vehicle, and a braking section for stopping the vehicle by braking when the vehicle moved the desired distance. Therefore, a slight movement of the vehicle is simplified and therefore the load to a vehicle driver is decreased.

Abstract: This invention discloses a method for detecting the presence of a moving object in a detection area, including emitting a sequence of bursts of ultrasonic energy into the area, receiving ultrasonic energy reflected from within the detection area, in response to the sequence of bursts, and generating a sequence of signals respectively responsive thereto, comparing each signal in the sequence with a preceding signal, to find a variation in the signals over the sequence of bursts, and analyzing the variation in the signals to determine the presence of the moving object. Apparatus for detecting the presence of a moving object in a detection area is also disclosed.

Abstract: A method for determining the location of an object in a passenger compartment of a vehicle in which ultrasonic waves are transmitted from a first transducer into the passenger compartment, waves reflected off an object in the passenger compartment are received by the first transducer and a first distance from the first transducer to the object is calculated based on the time difference between the transmitted waves and reflected waves when received by the first transducer. Further, different ultrasonic waves are transmitted from a second transducer into the passenger compartment which then receives reflected waves off the object and a second distance from the second transducer to the object is calculated based on the time difference between the transmitted waves and reflected waves when received by the second transducer. The approximate location of the object in the passenger compartment is determined based on the first distance and the second distance.

Abstract: An ultrasonic range finder which can effectively suppress the influence of direct transmission waves is provided. An ultrasonic range finder according to the present invention comprises a transmitting ultrasonic sensor, a receiving ultrasonic sensor, and a case which holds both ultrasonic sensors mounted and separated on the same surface, wherein a foam member fabricated to contain air bubbles is provided between the ultrasonic sensors within the case and the foam member is exposed to the surface of the case. Each of the sections of the transmitting and receiving ultrasonic sensors (which are held within the case) are covered with a second foam member and the matching layer sections of the transmitting and receiving ultrasonic sensors project beyond the surface of the case.

Abstract: A dimensional weighing apparatus is disclosed which has a weighing scale for determining the actual weight of a carton placed thereon, and associated therewith is a measuring frame and an optical sensing system for measuring the linear distance of the three axes of carton positioned on the scale necessary to determine the volume of the carton. A computer processing unit determines firstly whether the actual volume of the carton is less or greater than a predetermined threshold volume, and provides an operator with a signal indicating that determination.

Abstract: The invention concerns pulse echo distance measurement and in particular a method and apparatus for calculating such a distance by sensing multiple reflections of a given pulse signal. By sensing multiple reflections, and not just the primary echo, internal time delays which would otherwise cause systematic errors may be simply eliminated and the multiple readings obtained may be utilized to provide system self-diagnostic checks, eliminate spurious information and provide an accurate measure of distance. A particular advantage of the method is that very small distances between sensor and target may be measured.

Abstract: In a procedure for non-contact distance measurement, in particular to measure the distance from obstacles in the immediate vicinity of motor vehicles, measurements are made using a first measuring procedure, and in a first measuring range absolute values of the respective distance are determined. Using a second measuring procedure, relative values are determined in a second measuring range that overlaps the first. Absolute values of the first measuring procedure, which lie inside the overlapping range, are used to calibrate the relative values of the second measuring procedure.

Abstract: A method and apparatus for locating the user of a computer system and adjusting the sound from the system speakers. The computer system includes a computer, two speakers, a microphone, a signal processor, and an audio processor. The speakers emit a sound which is reflected from the user and other objects in the vicinity of the system. The invention includes an algorithm for determining which of the reflected sounds had been reflected from the user of the computer system. The character of the sound emitted by the computer system is then adjusted to enhance the sound effects at the location of the user.

Abstract: Method for processing echoes received in an ultrasonic liquid gauging apparatus includes the steps of transmitting at time t.sub.1 ultrasonic energy from an ultrasonic transducer toward a fixed target and a liquid surface; producing a transmission pulse corresponding to the time t.sub.1 ; receiving during a predetermined cycle interval a number (i) of ultrasonic echoes after t.sub.1 and converting each echo into a corresponding echo pulse having an associated time of arrival t.sub.i+1 ; and calculating the liquid level based on an averaged time of arrival of the second echo relative to t.sub.1 when it is known that the liquid surface is low.

Abstract: A gas gun is provided for generation of an acoustic pulse and subsequent detection of return reflections from the annulus of a well. The system includes a gas gun and a hand-held gas source. The hand-held gas source comprises: a two-part housing forming a chamber for receipt of a small CO.sub.2 gas cartridge commonly used for CO.sub.2 target pistols; means for piercing the gas cartridge and pressurizing the chamber; a coupling for releasable connection to a delivery assembly; a passageway leading from the chamber to the coupling; and a first valve in the passageway for controlling release of gas from the chamber.

Abstract: A time-domain reflectometer is disclosed for reliably measuring the level of a liquid in a tank. The reflectometer emits an acoustic signal into a waveguide that projects downwardly into the tank and receives a return acoustic signal reflected from the surface of the liquid. The time delay between the transmitted acoustic signal and the reflected acoustic signal is a measure of the level of the liquid, and the reflectometer converts this level measurement into a electrical current that is linearly proportioned between predetermined minimum and maximum values. In addition, the reflectometer incorporates a liquid- and vapor-impervious membrane disposed in the path of the transmitted and reflected acoustic signals, adjacent to the transmitter and receiver, to prevent the escape of liquid and vapor from the tank and to isolate the electronics, including the transmitter and receiver, from such liquid and vapor.

Abstract: In distance measurement on the principle of pulse transit time in each measurement cycle in a transmitting phase a transmission pulse having a given transmission frequency is emitted and in a subsequent receiving phase the envelope of the received signals is formed to determine the transit time of the useful echo pulse. For suppressing the fixed target echoes a broken line of several segments surrounding the envelope of the fixed target echo is formed for each fixed target echo. For each segment, information as to the amplitude of the end point of the segment, as to the changing direction and slope of the segment, as well as for the first segment information as to the point in time of the start of the first segment in the measurement cycle are stored.

Abstract: A car obstacle monitoring system which will not erroneously detect a distant obstacle as an obstacle around a car and can avoid an erroneous detection by relatively simple control even though it is arranged so as to emit ultrasonic waves of a single frequency. A control circuit 12 controls a right sonar 1, a left sonar 4 and center sonars 2 and 3 provided on the right side, on the left side and at the center of a car 5, respectively. The control circuit 12 has a timing element and a discriminating element. The timing element generates three emission modes including a first emission mode in which the right sonar 1 and the sonar 3 emit ultrasonic waves in synchronism, a second emission mode in which the left sonar 4 and the center sonar 2 emit ultrasonic waves in synchronism, and a third emission mode in which the right sonar 1 and the left sonar 4 emit ultrasonic waves in synchronism repeatedly without overlapping each other.

Abstract: A distance measuring apparatus includes a wave transmitting device for emitting a transmission wave. A wave receiving device is operative for receiving a reflection wave, which results from reflection of the transmission wave by a reflection object, as a reception wave. A time difference measuring device is operative for measuring a time difference between a moment at which the wave transmitting device emits the transmission wave and a moment at which the wave receiving device receives the reception wave. A distance calculating device is operative for calculating a distance to the reflection object on the basis of the time difference calculated by the time difference measuring device.

Abstract: Disclosed is a method of detecting the bottom of a waterbody in the presence of overlying submersed aquatic vegetation (SAV) and of characterizing physical attributes of that overlying vegetation. A narrow-beam hydroacoustic transducer is mounted on a mobile survey boat in a vertically-downward orientation. A rapid series of short pulses (pings) are generated by the transducer as the boat traverses a predetermined path within the waterbody. Raw hydroacoustic echo-level data is digitally recorded along with position data generated by some electronic position measurement system. The methodology for processing the raw signal is implemented in a digital computer algorithm which extracts hydroacoustic signal features and applies classification decision rules which were developed based on common physical characteristics of aquatic environments containing SAV. An apparatus for carrying out this method is also disclosed.

Abstract: Groundwater velocity and direction of flow are determined by insertion into borehole below the water table of a sound source and a plurality of sound sensors. A periodic sound signal is emitted by the sound source, which is submerged in groundwater at the bottom of the borehole. The sound signals are sensed by the sound sensors, which are also submerged in the water in the vicinity of the sound source. Owing to the Doppler effect, there is a shift in the frequency of the sound signals observed by the different sound sensors. The differences in frequency are determined by pulse counters and used to compute the components of groundwater velocity along north-south and east-west axes. The velocity of groundwater flow and its direction are determined by vector addition of the groundwater velocity components. These computational processes are carried out by an appropriately programmed microprocessor.

Abstract: An automatic frequency control loop for maintaining a center carrier freqcy fed to a notch filter for blocking out system reverberation includes, along with the conventional elements found in an automatic frequency control loop, a control switching circuit responsive to excessive frequency deviations beyond a predetermined range as established in the AFC loop. Such excessive deviations are likely present during the time when little, if any, reverberation energy is received by a receiver carried on a moving platform, or, when signals originating from high energy level sources of countermeasure energy are being received. An interposed, selective device is included in the control switching circuit to permit operation in one of several modes as the situation demands. Including the control switching circuit in an active homing torpedo is the preferred application, although the teachings of the invention are applicable to all situations when own doppler nullification and reverberation damping is desired.

Abstract: The present invention relates generally to inkjet printing mechanisms, and more particularly to an ultrasonic method for monitoring the ink level in an ink reservoir for an ink jet cartridge. This ultrasonic method includes the steps of sending an ultrasonic signal towards the ink reservoir, and receiving a series of reflected ultrasonic signals from the reservoir. In a processing step, the series of received reflected ultrasonic signals are processed in order to determine the ink level in the reservoir.

Abstract: A measuring apparatus and method for calculating height and weight of human subjects in one step. A scale having a weight sensor is provided to sense the weight of a subject standing thereon. A sonar head is positioned stationary a predetermined distance above the scale sufficient to permit a subject to stand upright on the scale and below the sonar head. The sonar head has a sound wave emitter and a plurality of sound wave receptors. A Digital Signal Processing circuit(DSP) is connected to the sonar head and is activated when the operator initiates a measurement. The data processing circuit is controlled by a software to calculate the weight and height of the subject. The apparatus and method also provides additional data on the subject, such as the body surface area, BA, body mass index BMI, percentiles height and weight. The (DSP) circuit produces a short burst of sound waves that travel downwards, hit the target (patient's head) and return towards the sonar head.

Abstract: A method of computing the location of air guns and hydrophones within a seismic spread utilizes a navigation network having a plurality of stations. The network provides a plurality of navigation observations. A number of the observations consist of magnetic bearings which are used to derive the hydrophone locations. The method includes the steps of:a. obtaining a set of observations from the network, each observation being obtained by using navigation devices whose origin system moves independent of the navigation reference point; andb.

Abstract: In a method for determining the position of an object relative to the background with ultrasound, a plurality of ultrasound transducers arranged in a row simultaneously transmit ultrasound in line-shaped fashion in the direction of an object scene and receive both the echo of the signal transmitted by the transducer itself as well as the echoes of the signals generated by the neighboring ultrasound transducers. On the basis of a reference measurement wherein no object is located in the measurement region, the amplitudes and the times of incidence of the echo signals are stored. In the following measurements with an object, the echo amplitudes and the times of incidence of the echo signals are again stored and compared by fuzzy logic to those of the reference measurement. As a result, this supplies the position of the object relative to the background.

Abstract: A method and apparatus for determining the length of a fluid conduit using acoustics is disclosed. The inventive method for determining the length L.sub.FC of an unblocked section of fluid conduit, the unblocked section of the fluid conduit having a proximal and distal end, comprises the steps of:(1) constructing a pressure containment system, the system comprising:(a) the unblocked section of the fluid conduit; and,(b) an extension conduit;(2) connecting a pressure change sensing device to the system, the pressure change sensing device being capable of sensing changes in the pressure inside the system;(3) filling the system with a fluid;(4) generating at least one pressure wave in the system;(5) timing the pressure wave from a timing starting point a known distance L.sub.3 from the pressure change sensing device;(6) measuring the time T.sub.

Abstract: A distance measurement device comprises at least one switch for generating a start signal, a distance measurement device for measuring the distance to an object in response to the start signal, a memory device for storing distance data measured by the distance measurement device, the stored data defining a plurality of measurement zones within the full range of distance measurement of the distance measurement device, and a judgement circuit for judging which measurement zone the result of the distance measurement performed by the distance measurement means belongs to from the plurality of measurement zones defined by the distance data stored in the memory device. In accordance with this configuration, division points can be set if an object is placed at an actual division point desired and a switch is pressed. Accordingly, when an operator sets the division point, it is unnecessary to depend on memory, perception, or calculation, and the setting of the division points becomes easier.

Abstract: Transmitted signals are used to accurately and remotely determine the veral distance of an earth-based receiving antenna above a surface, and hence can be used to determine the tide condition of a water surface. A signal is transmitted from a signal source as it moves either through air or space. An antenna whose height is to be determined with respect to a reflecting surface, such as water, receives the signal directly from the signal source and indirectly from the signal source by reflection of the signal from the reflecting surface. The sum of the directly and indirectly received signals form an interference pattern as the signal source is moved. Points on the interference pattern are selected at identical phase angle for each cycle of the pattern. The points are assigned reference numbers and the numbers are plotted with respect to a measurement indicative of the distance between the signal source and the antenna whose height with respect to the reflecting surface is to be determined.

Abstract: A ultrasonic sensor for detecting the location of objects disposed in a substantially gaseous environment includes a plurality of nodes arranged into a uniform network. A plurality of circular transducers are provided such that each transducer is disposed at a node. The center of adjacent transducers are spaced at a distance no greater than the wavelength of acoustic waves emitted by the transducers. A method of detecting the location of objects disposed in a substantially gaseous environment is also disclosed.

Abstract: A system and method for data entry and retroactive reconstruction of the relative position of features and objects, in particular with respect to scenes such as transitory occurrences, utilizing a signal transmitting and receiving distance determining device. In a particular embodiment, the system and method disclosed has especial applicability to the on-scene recordation and subsequent ex post facto reconstruction of traffic accident scenes by law enforcement officers and may be readily and efficiently implemented in conjunction with a commercially available laser-based speed and distance determining device otherwise usable for vehicle speed traffic monitoring functions utilizing either triangulation or baseline/offset mensuration techniques.

Abstract: A converter for use with a constant speed vehicle cruise control system including a speedometer for generating a self speed signal representative of the self speed of the vehicle and a speed adjustment control responsively coupled to the speedometer for maintaining the self speed of the vehicle at a preset speed. The converter adapts the control system to a constant distance system, and comprises a rangefinder for generating a distance signal corresponding to the distance of the vehicle from a front vehicle, and a distance-dependent speed adjustment device coupled to the rangefinder and to the speedometer for generating a synthetic-speed signal corresponding to the set speed required for maintaining a predetermined distance between the two vehicles. A selector switch allows either the self speed or synthetic-speed signals to be connected to the speedometer of the cruise control system.

Abstract: The method makes it possible, in particular, to measure distances which lie within the ambiguity zone of the ultrasonic transmission/reception unit. The ultrasonic transmission/reception unit comprises a single ultrasonic transducer which is operated in pulse-echo mode. The time t.sub.e1 of the first received echo is initially determined. If this time lies outside the double dead time 2t.sub.T, then the measurement is unambiguous and the propagation time of the sound, which is proportional to the difference between the ultrasonic transmission/reception unit and the object, is output. Otherwise, the propagation time of the sound is determined from the difference between the arrival times of two successive multiple echoes from the same object.

Abstract: A dispensing system includes a robot that controls the positional location of a dispenser that dispenses a bead of material, such an adhesive, onto a substrate and wherein a sensor monitors the geometric configuration of the material dispensed. The dispensing system also includes a control circuit which receives information from the sensor so as to monitor geometric characteristics such as height, width and cross sectional area in such a manner that statistical process data can be gathered and also to provide alarm indications whenever the height or width of the bead do not comply with predetermined characteristics. The control circuit also provides a closed loop feedback system so that the supply of material and the nozzle can be controlled in such a manner to modify the flow of bead material whenever a discrepancy or error is detected by the control circuit.

Abstract: A device for the measurement of distance with ultrasound is provided in which a transmitter emits a pulse-type signal which is reflected and is converted into an electrical echo signal in a receiver. The distance between transmitter and receiver is determined by measuring the transit time between the emitted and the received signal. Since the level of the echo signal as a function of the emitted signal depends on the characteristics of the reflector and on the distance between transmitter and receiver, inaccuracies may occur in the evaluation of the echo signal and these are avoided by varying a switching threshold or by varying the amplification of the echo signal or by modifying the radiated signal as a function of the previously received echo signal.

Abstract: A cruise control system for a motor vehicle includes a forward looking distance sensor adapted to sense vehicles moving in the same path as the equipped vehicle or in paths adjacent to the equipped vehicle, the system tracking vehicles in front of or in paths adjacent to the equipped vehicle and controlling braking or acceleration of the equipped vehicle in response to vehicles travelling in front of or on converging paths with the equipped vehicle, in order to maintain a safe distance between the equipped vehicle and vehicles in or entering its path.

Abstract: A method and apparatus for determining the depth of a marine target relat to the surface of the water which encompasses an analog processing circuit for detecting and analyzing signals reflected respectively from a target and the water surface, a timing and gating circuit respectively responsive to a target echo signal for initiating a timing sequence and to a surface echo signal for terminating the timing sequence, and a depth readout circuit for indicating the depth of the target below the surface at the instant the surface echo signal terminates the timing sequence.

Abstract: A ranging and data taking system, useful as an acoustic sediment classification system. The system launches acoustic pulses into a water column above a sediment bed of interest (seafloor, riverbed, etc.) and records echoes from the pulses. The recorded echoes are transmitted to a processor, which uses the echoes to classify the sediment. Disposed between the hardware for data acquisition, and the processor, is S-RAM (static read only memory). This decouples data acquisition and data processing, which increases the speed of the system sufficiently that the system can display processed data, such as sediment contour plots, in virtual real time.

Abstract: A circuit arrangement determines a distance of a motor vehicle from an obstacle in a near range by a displacement sensor instead of an ultrasonic measurement. The distance is determined, above a predetermined limiting value, in accordance with the known ultrasonic transit time measurement. In this range, by comparing the signals of the displacement sensor with the ultrasonic measurement a calibration can be carried out and a correction factor for the displacement sensor can be formed. The correction factor is taken into account during the measurement in the near range, as is the contour of the vehicle.

Abstract: In a first step, an individual echo is associated with each local maxima in the received ultrasonic signal. Subsequently, characteristic features such as time position, amplitude and form factor of each respective individual echo are detected numerically for the individual echo. In a second step, the mentioned features are subjected to a fuzzy evaluation. The features form the input variables of the evaluation. A multiple echo probability for each individual echo is available as the result. With this awareness, with the aid of the a priori knowledge and with the aid of the awareness of the history, it is possible, for example, to draw conclusions concerning the filling level of the bulk material in containers in which the surface of the bulk material is at times masked for the ultrasonic beam by the stirring apparatus.

Abstract: A container having affixed thereto an ultrasonic transducer, including a connection for electrically linking the transducer to electronic circuitry located outside the container. Flexible and semi-rigid containers having rigid structures surrounding the signal path of an ultrasonic transducer are also provided. In addition, adaptors are disclosed for use in connecting an ultrasonic transducer to a container. Such adaptors can include a rigid tubular member, a tubular outlet connected to the tubular member for draining liquid from a container, and a seat for engaging an ultrasonic transducer.

Abstract: An acoustic ranging and detection system comprises an acoustic transmitter for producing an acoustic ranging signal and first and second acoustic receivers positioned on either side of the acoustic transmitter. A support mounts the acoustic transmitter and both acoustic receivers for concurrent rotation about a central axis passing through the acoustic transmitter. A first motor is connected to the first acoustic receiver and is adapted to impart independent rotative movement thereto. A second motor is connected to the second acoustic receiver and is adapted to impart independent rotative movement thereto. A control system is responsive to echo signals from a target that are received by the first and second acoustic receivers to rotate the support to point the transmitter at the target and further operates the first and second motors to cause the respective acoustic receivers to be repositioned so as to manifest receiving beam patterns which exhibit central axes that intersect in the region of the target.

Abstract: A short range ultrasonic distance warning system is used as a parking aid in a motor vehicle. The entire system is active in the case of reverse gear being selected and low speed, and is deactivated automatically at higher speed. If reverse gear is not being selected, only the system part for front space monitoring is active at low speed of travel, while the system is once again automatically kept inactivated at higher speed. This implements a parking aid which is convenient and avoids unnecessary system activations.

Abstract: An ultrasonic probe utilized in an ultrasonic ranging system for determining fluid volume and/or fluid leakage in an underground storage tank, as well as monitoring fluid inventory, is provided which is characterized by (i) having its calibration reflectors positioned whereby each of the secondary echo packets formed by the calibration reflectors of the ultrasonic probe becomes imbedded into the trailing edge of a primary echo packet of another calibration reflector or to cause its secondary echo packet to be detected by the transducer after the transducer has detected a primary echo packet associated with the fluid surface, (ii) each of the calibration reflectors being positioned perpendicular to and offset from the longitudinal axis of the probe body, (iii) an ultrasonic sound wave dampening member fixedly positioned in the probe body between the transducer assembly and the tank bottom, the wave dampening member having a surface facing toward the transducer assembly wherein the surface is configured to damp

Abstract: An object detector for detecting metallic or non-metallic objects is disclosed which comprises a sound source such as a speaker (12) for generating impulse short sound bursts. A tube (16) conducts the acoustic signal from the speaker to the ground and at least one microphone M1-M3 is utilised for detecting reflections from the ground. A reflection from a buried object is compared with a reference signal which may be obtained from another microphone M1, M2 or earlier in time from the same microphone M3. The reflected and reference signals are subtracted to provide a difference signal and a difference signal is correlated with the original acoustic signal to provide an indication of an object. Time windows may be set to enable analysis of different depths to be obtained.

Abstract: The present invention is directed to provide an underwater detection system which can determine frequency components contained in echoes arriving from all azimuthal directions at high speed and enhance target discriminating capabilities by presenting such frequency components.The underwater detection system rotates a pair of ultrasonic receiving beams having a fixed phase angle difference, measures phase differences between two signals picked up by both ultrasonic receiving beams, determines carrier frequencies contained in target echoes from the phase differences, derives magnitudes and directions of moving velocities of targets from the carrier frequencies, and displays such target data in different colors. Furthermore, it provides such information as over-the-ground velocities of targets themselves upon compensating target velocity data with ship velocity data.

Abstract: A distance sensing device for a motor vehicle, positioned at the rear of the motor vehicle, for sensing a distance to an obstacle to the rear of the motor vehicle, has a brake light unit positioned in the interior of the motor vehicle at the rear window. At least one sensor for sensing the distance is provided. An optical display unit located within the brake light unit is provided, and the at least one sensor is connected to the optical display unit.

Abstract: A distance measuring method and apparatus in which first and second pseudo random signals which are the same in pattern but slightly different in period are generated to obtain a correlation output of the first and second pseudo random signals before transmission thereof as a reference correlation output, and the first pseudo random signal is directly transmitted toward a target or alternatively a carrier wave is modulated by the first pseudo random signal and transmitted toward the target. A correlation output of the signal reflected and received from the target and the second pseudo random signal is detected and the distance to the target is measured from the time interval between the reference correlation output and the received correlation output.