Abstract: A method and apparatus for tracing sewer connections with RFID PIT tags consists of using at least one radio frequency identification (RFID) passive integrated transponder (PIT) tag embedded within a protective outer covering, and at least one RFID reader and antenna system to trace the flow of a fluid within a plumbing system, sewer lateral pipe, sanitary or storm sewer system. The RFID PIT tag and protective outer covering are introduced in one point within the plumbing system, sewer lateral pipe, sanitary or storm sewer system, such as by flushing a toilet. Subsequent collection, or detection of the RFID PIT tag at another location within a sewer lateral pipe, sanitary or storm sewer system is used to establish the presence of a hydraulic connection between the introduction and collection or detection points.

Abstract: A hydrophone has a pair of end caps each disposed on a different open end of an air-backed cylinder of a piezoelectric ceramic material. An electrode or lead extends through one of the end caps and into the cylinder, and has a shape and a lateral width that extends across an interior of the cylinder and abuts an inner surface of the cylinder at multiple points.

Abstract: An active fixed block track circuit comprises at least a fixed block section, comprising at least two rails corresponding to each other, each having an isolation connector at two ends thereof and connected to a power supply unit and a traffic signal; a short driving unit, connected to each of the two rails within the fixed block section; and a detection unit, connected to the short driving unit. In this manner, not only the previous rail traffic signal circuit function where no more than one train may be allowed into the same fixed block section is maintained, but also another train approaching from the rear may be prevented from entering the fixed block section when the detection unit at the fixed block section detects an exceptional case happening at a neighboring fixed block section so that the traffic signal unit is switched into a stop traffic signal.

Abstract: A method forms a passive acoustic track to cue an active multistatic acoustic tracking system. The passive track cue reduces the false track rate in the active tracker by focusing search area and selectively initiating active tracks. The passive track originates from a fixed passive acoustic horizontal line array (HLA). The HLA cannot determine target range or resolve left-right ambiguity but can predict Closest-Point-of-Approach (CPA) events. For each CPA event, a cue is forwarded to the active system for initiation. The method presents a minimal parametric representation for a passive acoustic track and uses an algorithm to obtain initial estimated parameters to initiate the passive track more effectively. A performance evaluation is given. The method also includes conversion of the passive track to normalized-coordinates for use with multistatic tracking systems. The passive track quality is assessed to determine whether it is sufficient to justify cueing the active multistatic system.

Abstract: The different advantageous embodiments may provide an apparatus that may comprise a support structure, a number of acoustic sensors, and a controller. The number of acoustic sensors may be coupled to the support structure. The controller may be configured to control the support structure to change the spatial distribution of the number of acoustic sensors.

Abstract: A device for conducting ultrasonic inspections comprises a base. In addition, the device comprises a probe housing pivotally coupled to the base with a suspension system. Further, the device comprises an ultrasonic probe disposed within the probe housing and configured to transmit ultrasonic signals. The suspension system is configured to permit the probe housing to pivot relative to the base to transmit ultrasonic signals in a plurality of directions.

Abstract: Generating a planogram of a facility in real-time, includes positioning a wireless mobile device at a plurality of geometric positions within the facility. A location of the mobile device at each position is then established using a location mechanism. Each geometric position is then associated with that location of the mobile device. The planogram is then updated with information about the geometric position. The geometric positions are associated with physical objects modeled in the planogram. Non-geometric information can also be obtained at the location of the mobile device, and this non-geometric information can be overlaid onto the planogram.

Abstract: A top drive assembly may comprise a drive motor that provides rotational torque to a drill string for driving the drill string into the earth. A sensor and a transmitter may be located on a section of the drill string or on a device that can be incorporated into a drill string. The sensor may take measurements of the drill string that is rotating during the drilling operation. If the sensor is located near the top drive assembly, the sensor may take measurements of an upper portion of the rotating drill string during the drilling operation. The transmitter may wirelessly transmit the sensor information in real-time to a coordinator or main radio. The transmitter may also be located near the top drive assembly and during the drilling operation, may transmit from the rotating drill string while located in a position above the earth's surface.

Abstract: This invention relates to immersed moving bodies for which the activity requires knowledge of their absolute geographic coordinates. This is the case particularly for moving bodies performing site survey operations, excavations and more generally exploration operations. A moving body can equally well refer to an independent diver, a manned vehicle or an unmanned machine. The device is used by an immersed moving body for independent determination of its absolute geographic coordinates. The device, according to the invention comprises on board calculation means (31) associated with “surface” position means (32) consisting of a GPS or GALILEO type receiver, submarine positioning means (33) operating on the principle of homing in association with immersed fixed acoustic beacon (41) and a set of sensors (36) that the moving body (42) uses to determine its working depth, its horizontality, and the difference between the direction followed and a fixed direction, for example magnetic north.

Abstract: Phased array ultrasonic contact transducer, with a flexible wedge and a profilometer. This transducer applies to the non-destructive monitoring of an object and comprises: a set of elements that are rigidly integral with each other, at least part of the elements serving as ultrasound transmitters, a wedge whereof at least the front face is flexible to be applied against the surface of the object and the rear face of which is made integral with the set of elements, and a profilometer to measure surface variations and supply signals representative thereof to allow the transmitters to create a focused ultrasonic beam whereof the characteristics are controlled in relation to the object.

Abstract: A method of non-destructively identifying and characterizing defects in a rotary drill component is provided. The method includes providing a drill component and an ultrasonic test system including a phased array ultrasonic transducer (PAUT). The method also includes acoustically coupling the PAUT to a surface location, transmitting focused ultrasonic acoustic waves at the location into the PAUT and recording a reflected acoustic response corresponding to a portion of a predetermined volume of a microstructure of the component associated with the location on the surface. The method also includes storing the response and moving one of the transducer or the component to a plurality of unique locations representative of the predetermined microstructure and repeating these steps. The method also includes processing the responses and providing an output signal to an output device configured to provide an output indicative of differences in the output signal within the predetermined volume of the microstructure.

Abstract: Embodiments for determining the bearings to targets from a remote location are disclosed. The apparatus consists of an array of acoustic sensors that is capable of autonomous flight. The array may be large in diameter, approximately one meter or greater. The apparatus is capable of navigating its flight to arrive at a predetermined location, measuring acoustic sound waves emitted by targets both during flight and after landing. The apparatus may then calculate the bearings to the targets and transmit this information to a remote location.

Abstract: Embodiments for determining the bearings to targets from a remote location are disclosed. The apparatus consists of an array of acoustic sensors that is capable of autonomous flight. The array may be large in diameter, approximately one meter or greater. The apparatus is capable of navigating its flight to arrive at a predetermined location, measuring acoustic sound waves emitted by targets both during flight and after landing. The apparatus may then calculate the bearings to the targets and transmit this information to a remote location.

Abstract: Embodiments for determining the bearings to targets from a remote location are disclosed. The apparatus consists of an array of acoustic sensors that is capable of autonomous flight. The array may be large in diameter, approximately one meter or greater. The apparatus is capable of navigating its flight to arrive at a predetermined location, measuring acoustic sound waves emitted by targets both during flight and after landing. The apparatus may then calculate the bearings to the targets and transmit this information to a remote location.

Abstract: Methods and systems for estimating one or more orientation parameters of a seismic apparatus are described. One method comprises initiating an acoustic signal from an acoustic transmitter in a marine seismic spread comprising a streamer, the streamer having at least two nodes separated by a fixed distance; measuring a first and a second difference in acoustic arrival times at the nodes for the acoustic signal; and using change in the second difference from the first difference to estimate orientation of the streamer. It is emphasized that this abstract is provided to comply with the rules requiring an abstract, which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: The invention relates to an identification chip for insertion in an object located in a liquid. The identification chip comprises an acoustic resonator (100), which exhibits a number of distinct resonant frequencies, where the combination of resonant frequencies is unique to the identification chip. This enables the identification chip to be identified by exposing it to an acoustic polling signal, measuring an acoustic response signal and analysing the frequency of the response signal. The resonator (100) comprises a cavity-forming part (110, 120) and a membrane (130). The acoustic resonant frequencies are determined by at least one cavity (140), which is enclosed by the cavity-forming part (110, 120) and the membrane (140). The identification chip can be implanted in a fish, with the object of identifying the fish when it is located in water.

Abstract: A method and system for relative positional tracking of a signal source is disclosed that requires no phase synchronization between the tracked source and tracking system. A signal source transmits a repeating signal. The virtual wavelength of the repeating signal establishes zones of coverage. The system's sampling rate (or sync clock) corresponds to the frequency of the repeated signal. One or more ultrasonic transceivers placed within the desired coverage area capture the transmitted signal. Before tracking begins, a coordinate system origin (X=0, Y=0, Z=0) is established so that all tracking calculations are relative to the origin. Relative time-of-flight measurements are made by comparing the received signals against a sync clock. Tracking is accomplished by triangulating distance measurements received from the ultrasonic transceivers.

Abstract: Robot and remote controlled devices have been utilized for information gathering purposes. However these robotic vehicles lack efficiency because they are not capable of operating out of doors or where the sensors and apparatus located on the robots are subject to harsh environments. The present invention provides a new and unique manner of overcoming these problems by providing a platform system that is placed upon existing robots without requiring adjustments to these devices. The platform effectuates easy installation of a plurality of sensors and apparatus on its top surface while providing internal housing for its wires and components, thereby providing a water, dirt and dust resistant environment which leads to better equipment function and ease of maintenance and repair.

Abstract: An apparatus for detecting the position of an object moveable along a predetermined travel path. The apparatus includes an acoustic signal waveguide, a signal input coupler, at least one signal output coupler, and means for generating. The acoustic signal waveguide extends along the travel path and having a predetermined, uniform speed of propagation of sound. The signal input coupler is located on the moveable object, to couple a clocked acoustic signal into the acoustic signal waveguide. The at least one signal output coupler is arranged at one end of the acoustic signal waveguide and is connected to an evaluation unit for determining the propagation-time of the sound signal from a position at which it is coupled in to the at least one signal output coupler and for generating a signal representative of the instantaneous position of the moveable object on the travel path.

Abstract: A method of determining the bearing of a source of a sonar signal comprising determining the phase of a cyclic variation of the output signal of a sonar detector having a directional characteristic which occurs as the orientation of the detector, and hence its characteristic, is rotated. In a preferred method the sonar detector output is spectrum analysed at each of a plurality of different orientations of the detector to provide for each orientation a signal representative of the amplitude of a component of the signal produced by the source of a chosen frequency. The signals so obtained are then arranged to form a time series of samples of said component as the orientation of the detector is rotated at a predetermined frequency and the time series used to analyse the spectrum of the signal defined by the time series and thereby determine the phase of the sinusoidal component of the signal defined by the time series at the predetermined frequency. Apparatus for carrying out the method is also disclosed.

Abstract: A method for spectral balancing of near- and far-offset seismic data, whereby velocity and offsets are determined for the seismic data. First, an NMO stretch compensation filter is created by the following steps. A frequency spectrum of the near-offset seismic data is estimated and a stretch factor &bgr; is calculated for the frequency spectrum, using the velocity and the offsets. A stretched frequency spectrum of near-offset seismic data is calculated, based on the stretch factor &bgr;. The frequency spectrum of near-offset seismic data is divided by the stretched frequency spectrum of near-offset seismic data, generating a first frequency response filter. High frequency gain is limited in the first frequency response filter, generating a first gain-limited filter. The first gain-limited filter is convolved with a low pass filter, generating the NMO stretch compensation filter. Then the NMO stretch compensation filter is applied to the seismic data.

Abstract: The invention relates to an apparatus for detecting the position of an object moveable along a predetermined travel path, comprising: an acoustic signal waveguide extending along the travel path and having a predetermined, uniform speed of propagation of sound; a signal input coupler located on the moveable object, to couple a clocked acoustic signal into the acoustic signal waveguide, signal output couplers at both ends of the acoustic signal waveguide and each being connected to an evaluation unit for determining the propagation-time difference of the sound signal from a position at which it is coupled in to the signal output couplers and for generating a signal representative of the instantaneous position of the moveable object on the travel path, wherein a calibration signal input coupler connected to a calibration acoustic signal generator for a calibration acoustic signal is provided on one of the signal output couplers, the evaluation unit calculating a correction variable for subsequent determinat

Abstract: A method and apparatus for measuring the depth of fluid in a well and for controlling the speed of a pump which pumps fluid out of the well according to the measured depth is disclosed. The depth of fluid in a well is measured by sending an acoustic pulse into an annulus between the well casing and the production tubing and sensing reflections of the acoustic pulse from collars on the tubing and a reflection from the fluid surface. Since the collar spacing on the production tubing is known, the distance from the top of the well to the surface of the fluid can be obtained by accumulating the distance associated with the collars detected in the reflection signal. The collar reflections are sensed by converting the reflected acoustic wave into electrical signals and then amplitude demodulating the broadband electrical signals.

Abstract: The position of an object is tracked underwater. Prior to tracking, the object is tagged with an acoustic transmitter. It is important that the transmitter emits sound waves having a frequency of at least 200 kilohertz (kHz) because it has been found that these transmitter frequencies provide better tracking data in noisy environments than conventional transmitters operating at 50-60 kHz. The acoustic transmitter is located by a split-beam transmitter. The position of the object can be accurately tracked by using two split-beam transducers, synchronization of transducer and transmitter, or echo ranging.

Abstract: A navigation system and method for identifying a position or navigating an autonomous robotic platform within an area is provided including a moveable device having an acoustic transmitter for transmitting an acoustic signal, an electronic processor device and an RF receiver; and three or more beacons positioned proximate the area, each beacon including a signal receiving apparatus responsive to the acoustic signal and an RF transmitter, the acoustic signal and the RF signal received from each of the beacons being processed in the electronic processor device to identify the location of the platform within the area.

Abstract: The present invention relates to a moving body control apparatus wherein operating control flexibility and system maintainability are improved by carrying out moving body travel control by transfer of ultrasonic wave signals between moving bodies, without intervention of a ground apparatus. An ultrasonic wave transmission apparatus (1) is provided on one train (A), and an ultrasonic wave reception apparatus (10) and a signal processing circuit (13) are provided on another train (B). The timing of transmission and reception of ultrasonic wave signals is synchronized by timing signal generating circuits (2, 11) on the respective trains, and the ultrasonic wave signals are transmitted and received via a metal transmission medium (30). The reception side train (B) measures the transmission time for the ultrasonic wave signal by means of the signal processing circuit (13), and based on the measurement result generates information necessary for train travel control.

Abstract: A first system for locating a portion of an underground sewer includes a buoy which is released into the sewer. The buoy is carried to the portion of the sewer by a flow of fluid therein. An electronic tracking system tracks the buoy during its travel through the portion of the sewer to thereby locate the portion of the sewer. A second system includes a plurality of buoys distributed along a tethered line which are released into the sewer. The plurality of buoys are carried to the portion of the sewer by a flow of fluid therein. A location of each of the plurality of buoys within the portion of the sewer is sensed to thereby locate the portion of the sewer. The plurality of buoys are then removed from the sewer by retracting the tethered line.

Abstract: A method for selecting a set of four target bearings from a plurality of bearing measurements to optimize rapidity, accuracy and stability of a target track solution in a bearings-only target motion algorithm. Four bearings are selected to generate the deterministic solution by first selecting a candidate bearing set, then computing a set of "n" solutions from the candidate set and others adjacent thereto. Motion parameters are then computed, and any solution exhibiting parameters outside a user defined deviation from the mean is discarded. The mean target parameters of the remaining solutions may again be computed, and further culling out performed, until the desired distribution is achieved. An optimal solution is chosen as the solution from the remaining sample space that is closest to the mean in target range, course and speed.

Abstract: This invention is in the field of underwater ultrasonic communications systems, more particularly, underwater acoustic homing devices suitable for diver direction finding. This invention utilizes a single omnidirectional sound source and a simple receiver, located in close proximity to a scuba diver's torso and equipment. The acoustic discontinuity of the diver's torso and equipment provides the required directional sensitivity, thus allowing the device to incorporate the desirable characteristics of flexibility in range in combination with a simple receiver housing.

Abstract: A method and apparatus for determining position of a vehicle in a tank of fluid. At least one transducer is disposed on the vehicle and a plurality of transducers are disposed on the outside wall of the tank. The transducers are arranged in a substantially common plane. The travel time of energy can be measured between any two of the transducers. Accordingly, the velocity profile of the liquid can be determined based on travel times measured between the transducers on the tank and position can be determined based on travel times measured between the transducers on the vehicle and the transducers on the tank.

Abstract: A control system connected to a passive underwater transducer array is located remotely from the array, e.g. above the surface of the water, to localize an underwater source of acoustic energy in a relatively simple manner by introducing listener-motion, such as head turning or body motion of a listener, into the sound localization process and does so without any underwater mechanical linkage of any kind. This is achieved by a pair of listener-motion coupled potentiometers, referred to as mixing-pots, located at the site of the listener, being connected to the outputs of an array of passive acoustic transducers, with the two outputs of the mixing-pots being coupled to a pair of headphones worn by the listener.

Abstract: An apparatus and method for identifying a conduit at a second location remote from a known first location of the conduit, characterized by a vibration device and means for removably coupling the vibration device to a wall of the conduit for transmission of vibration to and/or generation of vibration in the conduit, thereby enabling identification of the conduit at the remote second location.

Abstract: A self-steering platform system incorporates at least three and preferably four microphones circumferentially spaced about the platform which is mounted for movement preferably around two mutually perpendicular axes. A sound source is selected and separate audio signals from the microphones are analyzed by a control which based on differences between the signals from the microphones emanating from the selected source determines the location of the selected source. The orientation of the platform is then adjusted by the control relative to the selected sound source. The present invention is particularly useful for mounting a shotgun or parabolic microphone to enhance sound from a selected source.

Abstract: A performer tracking system, and an associated method, for tracking movements of at least one performer upon a stage. A plurality of signal transmitters are positioned about the stage and transmit electromagnetic signals. Performers on the stage carry transponders which receive the electromagnetic signals and, responsive thereto, generate coded sound signals. Sound signal receivers positioned together with the signal transmitters receive the sound signals. A controller determines positions of the transponders and, hence, the performers carrying the transponders and causes spotlights to track the performers.

Abstract: Briefly, according to the invention, a noise-cancelling microphone apparatus (400) is disclosed. The microphone (400) comprises a sound transducer (106) for converting sound waves to electrical signals and means for substantially preventing ambient noise from being converted to electrical signal. A circuit (100) is provided for determining the level of noise not prevented form being converted to electrical signal. The microphone (400) further includes a display (148) for indicating when the level of the ambient noise being converted to electrical signal is above a predetermined level.

Abstract: A method and apparatus for detecting the location of subterranean pipe includes sensors 24 and 26 which detect seismic energy. A pulsing valve (20) is disposed on one end of a water line (10) to allow water to intermittently flow and be shut off. This results in a water hammer effect which send shock waves (22) outward from the pipe (10). This is detected by the sensors (24) and (26) and then transmitted to a detector (32) to provide a differential indication. The locations of the sensors (24) and (26) will determine the differential balances therebetween such that when the sensors (24) and (26) are directly over the pipe (10), an indication of the location of the pipe is provided. Further, a reference sensor (19) is provided to allow distance measurement along the pipe by measuring the difference between the received energy at sensor (19) and either of sensors (24) or (26).

Abstract: A monoport airgun for seismic exploration has a single discharge port extending continuously for 360.degree. around its longitudinal axis. This airgun has a first housing providing a firing chamber containing pressurized gaseous fluid (gas) and a second housing providing an operating chamber. The first and second housings are positioned in alignment along the longitudinal axis. They are spaced apart along this axis for defining the discharge port between them extending continuously around the axis. The two housings of the monoport airgun are interconnected solely by a guide member concentric with the axis. A shuttle encircling the guide member is movable therealong between closed and open positions. In closed position, the shuttle closes the firing chamber for retaining pressurized gas therein. In open position, the shuttle opens the firing chamber to the discharge port for allowing pressurized gas to blast from the firing chamber through the discharge port.

Abstract: A method for combating a submerged target object through the intermediary of an active body which is deployable in an airborne mode, and which picks up a sonar contact with the target object from a helically descending searching trajectory below the water level. Also disclosed is an arrangement for combating a submerged target object, especially a double-hulled submarine, through the intermediary of an active body deployable in an airborne mode which is equipped with a sonar installation and with guidance media for the traversing of a helical gliding search trajectory. Upon contacting a target through the intermediary of a searching sonar which is more simply constructed in comparison with a homing sonar, the active body launches an effector which is equipped with an extremely rapid drive into linear attacking trajectory tangentially to the searching trajectory, and wherein the effector will detonate a warhead upon impact against a target.

Abstract: Aquatic animal finder apparatus and method include one or more passive transducers for converting sounds, including bio-soundwaves from a living aquatic animal source traveling in a body of water, to electrical signals, the transducer is caused to scan about a selected axis, the electrical signals are filtered to eliminate all man-made signals of a periodic character and pass bio-sound electrical signals. A discriminator is connected to the filter and programmed to pass a predetermined pattern of the bio-soundwave electrical signals constituting a sonic profile, signature or imprint of a selected aquatic animal. The direction of a selected aquatic animal is detected and presented to the user and range, depth and direction of movement of the selected aquatic animal are determined solely from the biosound signals received from the aquatic animal.

Abstract: A method and apparatus for detecting the location of subterranean pipe includes sensors 24 and 26 which detect seismic energy. A pulsing valve (20) is disposed on one end of a water line (10) to allow water to intermittently flow and be shut off. This results in a water hammer effect which send shock waves (22) outward from the pipe (10). This is detected by the sensors (24) and (26) and then transmitted to a detector (32) to provide a differential indication. The locations of the sensors (24) and (26) will determine the differential balances therebetween such that when the sensors (24) and (26) are directly over the pipe (10), an indication of the location of the pipe is provided. Further, a reference sensor (19) is provided to allow distance measurement along the pipe by measuring the difference between the received energy at sensor (19) and either of sensors (24) or (26).

Abstract: An ultrasonic tracking system comprising a transmitting unit and a drive unit. The transmitting unit is carried by the subject to be tracked and produces brief, periodic ultrasonic bursts. The drive unit has an ultrasonic receiver and a motorized assembly capable of tilting and panning an attached camera in response to control signals from the receiver. This receiver employs three ultrasonic microphones located at three of the four corners of an imaginary square centered on and perpendicular to the axis of the camera lens. The receiver measures the relative arrival times of signals received by the microphones, determines the direction and degree to which the camera is not pointed directly at the subject, and supplies control signals to the motorized assembly, to drive motors to re-orient the camera (and receiver) to point toward the subject.

Abstract: A system for detecting the location of an underground portion of a sewer line. A vibration or sound of a predetermined frequency is introduced into an accessible (e.g., above ground) portion of the sewer line. The vibration is allowed to propagate through the sewer line and into the underground portion of the sewer line. The location of the underground portion of the sewer is identified by sensing the vibration by means of a detector located at the ground surface or in an inserted "in ground" device above the underground portion of the sewer line.

Abstract: A dual axis transducer assembly comprises a transducer (20), a yoke (24) which mounts the transducer for oscillating movement about a substantially horizontal axis. A turntable (28) mounts the yoke and hence the transducer for oscillating motion about a vertical axis. Separate motors (10) and (12) supply motion to the transducer and control means (84), (86), (88) are employed to control the operation of the motors.

Abstract: A sonar transducer comprising a stack of an even number of antennae with identical linear networks. The stack is driven by a reciprocating rotary movement of low amplitude, with the antennae alternately emitting and receiving with each half wavelength of the rotary movement. The emitting antennae as well as the receiving antennae are mutually staggered by an angle equal to the angle of rotation of the assembly. The assembly of receiving antennae are staggered with respect to the assembly of emitting antennae by an angle equal to the phase delay of an emission lobe with respect to the corresponding reception lobe.

Abstract: A sound source searching device for searching an objective sound source out of a plurality of sound sources, is disclosed. The device comprises an intensity probe provided with one pair of microphones, pulse motors for rotating the probe on the horizontal and vertical planes, a computer for calculating acoustic intensity corresponding to the frequency of the objective sound source from the sound pressure signal generated by the intensity probe, an interface device provided with pulse motor driving circuits for driving the pulse motors in accordance with the instructions of the computer by predetermined angles and an indicator for indicating the direction in which the acoustic intensity is the minimum on the horizontal and the vertical planes, as the direction of the objective sound source.

Abstract: An acoustic direction finding method utilizes correlation between the signals of plural sound pickups on a rotating base. As the base rotates the pickups receive signals from a source of sound which is the target for which direction information is to be obtained, these signals are shifted in time from one pickup to the next. The base is rotated substantially at constant speed with one full rotation being divided into a plurality of angle sections. The pickup signals are correlated in the individual succeeding angle sections, thus obtaining a correlation function with a correlation peak corresponding to the target direction for each angle section. The correlation functions of the same angle section are added to each other with successive rotations of the base. A curve generated by the correlation peaks is then smoothed and utilized to determine the direction of the target.

Abstract: An apparatus for locating, classifying and identifying underwater marine animals by means of the sounds they make includes an elongated submersible array adapted to be towed in various directions. The array is made up of subarrays of multiple hydrophones which are arranged along the length of each subarray in groups. By changing the combinations of groups, the frequency response and the directional sensitivity of the array can be varied. The outputs of the groups can be selectively analyzed both visually and audibly for characteristic fish sounds. The received sounds are classified and used for the identification of newly found fish.

Abstract: The present invention is directed to a detection system which forms reception beams successively in a series of angular directions. The detection system comprises receiving means for receiving incoming signals in such a manner that the frequency of the incoming signals is varied in accordance with the Doppler effect, and a matched filter for pulse-compressing output signals from said receiving means, with output signals from said matched filter being displayed in an indicator.

Abstract: An apparatus for and method of characterizing an acoustic field, and particularly of visually characterizing the field. An acoustic receiving transducer means is moved to a plurality of predetermined coordinate and angular positions in the acoustic field, and for each such position an electrical signal indicative of a parameter of the acoustic field is stored in a memory. The information in the memory is selectively retrieved to activate an electronic display means, and to expose film if desired, to provide a visual "map" of the acoustic field parameter detected.

Abstract: Means for mounting a member functioning with a directivity to a mounting station of an associated device or the like. A housing for the member with its functional end surface exposed to the exterior is tapered at the periphery toward the other end to be, for example, hemispherical and rotatably born at diametrally opposed positions adjacent the functional end surface by both ends of a semiarcuate bearing means, the mounting station has a hole including peripherally opposing grooves of a size and shape capable of slidably engaging with the tapered periphery of the housing and receiving semiarcuate body of the bearing means, the housing is inserted in the hole on said the other end side, and the semiarcuate body of the bearing means in the inserted position of the member engages slidably with a resilient means acting to resiliently urge the tapered periphery of the housing against peripheral edge of the hole.