Abstract: Ultrasonic transmitting and receiving apparatus comprises a transmitter operable in response to a program to emit an ultrasonic signal and a receiver preprogrammed with a plurality of functions actuable in response to a said ultrasonic signal from the transmitter. The transmitter may comprise a PC 10 with a loudspeaker 18 and the receiver may comprise a stuffed toy 12 housing a microphone 14 and a microprocessor decoder and controller 16. Decoded signals may actuable motion, visual and audio functions of the toy.

Abstract: An acoustic transponder method and apparatus provides a high degree of frency and target strength selectivity by utilizing two or more concentrically disposed, hollow spheres each containing acoustically refractive fluids. The invention provides the possibility of using spheres of a variety of diameters and as well a number of different refractive fluids, enabling the production of an acoustic transponder having a wide variety of selective frequency responses as well as effective target diameters.

Abstract: The harness comprises a plurality of elements, such as light detectors, a laser emitter and a master control unit. The elements are communicating by means of ultrasonic signals. Such signals provide a secure communication over a short distance while being impossible to detect from larger distances. Upon initialization of the harness, the master control unit initializes all elements to respond to a common identification code, which identification code can be updated automatically during later operation.

Abstract: A navigational device (10) for assisting a scuba diver in determining a direction toward and a distance from a dive boat (12) or to a buoy near the shore at which point the dive originated. The navigational device (10) includes a transponder unit (16) carried by a boat (12) and an interrogator unit (34) carried by a diver. The interrogator unit (34) includes at least one transducer (68) positioned for detecting signals from the transponder unit (16). Direction and distance indicators (46,50) are carried on the surface of the interrogator unit (34) for visual indication to the diver. The transponder unit (16) repeatedly pulses an identification signal to be received by the interrogator unit (34). When a valid identification signal is received by the interrogator unit (34), the direction from which the signal was received is determined and displayed. When the distance to the boat (12) is required, a signal is emitted from the interrogator unit (34).

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: The invention relates to a transponder comprising a closed glass casing in which electrical components are placed, wherein the glass incorporates iron oxide, a method for the production of such a transponder, the use of iron oxide in the glass of a closed glass casing of a transponder and a method for the identification of animals with the use of such a transponder.

Abstract: A remote-control system for closures with a movable hand transmitter with at least one transmission key, this transmitter generating and radiating directed coded control signals upon actuation of the transmission key of the hand transmitter. At least one first receiver unit is tuned to receive the control signals radiated from the hand transmitter and is arranged on a motor vehicle and triggers switching effects on a remotely controllable vehicle locking after the received control signals have been identified as acceptable. At least one second receiver unit is tuned to receive control signals radiated as a result of the actuation of the transmission key of the hand transmitter for remotely controlling a remotely controllable access control device external to the motor vehicle. This second receiver unit is arranged outside the motor vehicle and triggers switching effects on the access control device after the received control signals have been identified as acceptable.

Abstract: The present invention relates to an echo repeater/beacon system for use ooard marine vessels and platforms. The system includes a hydrophone for receiving an incoming acoustic signal from a remote station, an on-board computer for analyzing, detecting, shaping, collecting and storing up to 10 seconds of a shaped version of the incoming signal for later transmission as an echo signal, and a transmitting transducer for transmitting the echo signal. The on-board computer also is used to generate a beacon signal at a desired frequency and a desired repetition rate.

Abstract: This invention discloses electronic circuit that can be either embedded in n oceanographic sonobuoy housing or used as stand-alone equipment and which establishes and generates sonar signals of a repetition rate, pulse length, and amplitude pulse shape which are all programmably variable, selectable and determinable. A plurality of predetermined sonar pulse "profiles" are stored in a read only memory (ROM). A particular profile is selected from this memory and this profile is generated point by point at a selected frequency.

Abstract: A compact, sound activated device for repelling house cats from indoor surfaces and areas. When triggered from a remote location by a sharp audio signal such as that of a human handclap, the device produces a deterrent sound which repels cats from the area or surface upon which the device is placed. The deterrent sound is audible within the normal range of human hearing and terminates automatically after several seconds. The device, comprising a single housing, is battery powered and has external controls for regulating handclap sensitivity, deterrent sound volume level, and current flow from the battery.

Abstract: A top mounted buoy signaling device for marine navigation which is selectively activated in response to a coded address signal. The buoy signaling device includes a buoy having a top mounted receiver assembly which is activated by a transmitter assembly. The receiver circuit, transmitter circuit and antennas therefor are printed on circuit boards. The transmitter circuit includes an encoder chip which is preset to provide a coded address. The coded address is utilized to modulate a carrier signal to provide a coded address signal to activate the receiver circuit. The receiver circuit includes a decoder chip which is preset to the coded address of the corresponding transmitter. A lamp driver subcircuit is enabled in response to the coded address signal. The lamp driver subcircuit includes a master timer subcircuit which maintains the driver subcircuit in an operative condition for a predetermined period of time and a flash timer subcircuit which periodically energizes a lamp to provide a flashed output.

Abstract: A transponder that responds differently to two different input signals. The first input signal is at a first frequency. The first input signal is detected by a first powered detector that operates at the first frequency. The transponder responses in a first mode to the first input signal. The second input signal consists of short pulses at the first frequency and at a second frequency. The transponder responds to short pulses at the first frequency by powering a second detector. The first and second detectors then detect the second input signal. The transponder responds in a second mode to the second input signal.

Abstract: An underwater acoustic control system for use in a subsurface unit receiv coded signals. A hydrophone receives the signal and enables an electronics package to supply a control pulse which could activate a switch or fire a squib. A timer is included in the package to provide a delayed turn-on of the receiver circuit for as long a period as desired.

Abstract: An underwater location beacon emits a continuous wave signal which is phase-shift modulated by a pseudo-noise, spread spectrum code. This signal is detected with an exact replica of the transmitted code. To an unauthorized observer without the replica, the transponder's signal is indistinguishable from background ocean noise. The spread spectrum code allows extraction of the signal from high levels of ocean noise, providing an increased detection range, jamming resistance, covertness, and unique signals for each pinger. The outputs of the surface spread spectrum receiver are used with automated location algorithms. Several receivers at different surface positions provide the underwater coordinates of the pinger's location.

Abstract: A marine transponder system which is selectively activated to produce a predetermined signal pattern of light/sound/radio transmissions for maritime devices and structures such as navigational aids, mooring, docking or slip facilities and/or EPIRBs and other emergency signalling devices. A remote transmitter is used to broadcast an uncoded or coded signal at a predetermined frequency to activate the marine transponder system. The transponder system includes an RF receiver tuned to the predetermined frequency, and optionally a decoder unit for verifying the coded signal. Upon receipt of the transmitted frequency signal, the transponder system causes an omni-directional light/sound/radio source to be energized to produce the predetermined signal pattern. The marine transponder system may be an add-on adapted for integration with existing navigational buoys, a standalone buoy, a package configured for mounting on a dock, pier or boat, or a package adapted to be mounted on a life vest/preserver.

Abstract: The invention relates to a method and a device for measuring a distance by means of an ultrasound. A drawback of this type of known methods for measuring a distance is that the transmitting and the receiving devices are separate, and they are designed to function according to whether they are positioned at a point of origin or at a target point of a measuring interval. For solving this problem, transmitter-receiver units (LVA, LVB) at the ends of a measuring interval are identical and interact continuously with each other so that the measuring result can be read in both devices.

Abstract: Tracking and location of a high speed water rentry vehicle is assured by the inclusion of an acoustic source. An acoustic generator in the form of a piezoelectric transducer is potted in polyurethane and fills a volume aft of a disc-shaped wall in the re-entry vehicle. The potting compound couples the acoustic generator to the metal skin to enable acoustic transmission from the vehicle to the tracking range. Optionally, a layer of material is interposed between the potting compound and the vehicle's metal skin to aid in acoustically coupling the generator's output to the metal skin. No structural modifications of the entry vehicle are required yet the pinger is capable of sustaining re-entry shock.

Abstract: Disclosed is a method for measuring a distance by using a radio-wave and an ultra-sonic wave. The method includes the steps of generating a certain start pulse in the form of a radio-wave between a measuring position and a position to be measured from the measuring position, receiving the radio-wave at the position to be measured while simultaneously generating an ultra-sonic wave from the same measuring position, determining a time difference between the moment of generating the start pulse and the moment of receiving the ultra-sonic wave, and multiplying the obtained difference by the sonic velocity.The method of measuring distances by utilizing the radio-wave and the ultra-sonic waves is very accurate without false operation and is simple, brief and convenient to use.

Abstract: A remote sensing transponder system is disclosed including apparatus for sensing gamma radiation levels proximate thereto, generating a signal indicative of the sensed radiation level, and transmitting an RF Signal modulated with the generated signal to a remote receiver in response to an interrogation signal from the receiver. The transponder further includes a pressure sensing device for sensing overpressure shockwaves such as caused by a nuclear blast and further modulating the transmitted RF Signal to indicate the detection of such a shockwave.

Abstract: A memory suitable for use as a responder, comprising:(a) receiver means for receiving a transmitted signal S1;(b) generator means (76) for generating a carrier component of a transmittable signal S2;(c) logic means (L.sub.2) for enabling signal S2 to be in mathematical relationship with signal S1, said logic means comprising:(i) at least one memory means (60) for storing code;(ii) at least one modulation means (65) for modulating said carrier component of signal S2, the modulating being under control of at least a portion of said stored code, such that signal S2 is in coded mathematical relationship with signal S1; and(d) transmitter means (T.sub.2) for transmitting signal S2.

Abstract: Apparatus which provides both range and bearing information between a transponder and a transponder interrogator. The interrogator transmits an acoustic interrogating pulse which is received by the transponder and in response thereto transmits back a first signal of a certain frequency f1. Two spaced apart hydrophones on the transponder provide their respective output signals to a phase meter, the output signal of which is indicative of the direction, that is, bearing, from which the interrogating pulse impinged. The phase meter output is converted to a corresponding time delay after which a second signal of a frequency f2 is transmitted. A counter in the interrogator starts counting upon transmission of the interrogating pulse and stops upon reception of the first signal of frequency f1. A second counter of the interrogator starts its count when the first counter turns off and terminates its count when the second signal f2 is received.

Abstract: Transmitting and receiving circuit for an apparatus for the automatic identification of objects and/or living organisms, including a stationary interrogator and a transponder fastened to the object or living organism to be identified, the interrogator including an energy transmitter, a signal transmitter, a first directional coupler connected to the energy and signal transmitters for receiving outgoing waves from the transmitters and for decoupling a first energy component from the outgoing waves, a first transmitting and receiving antenna, a second directional coupler being connected in series with the first directional coupler and being connected to the first transmitting and receiving antenna for receiving returning waves from the transponder and for decoupling a second energy component from the returning waves, an adjustable attenuator connected to the first directional decoupler for receiving the first energy component, an adjustable phase shifter connected to the adjustable attenuator for receiving the

Abstract: Method and apparatus for determining the length of a tubular member such as a pipe are disclosed. A burst of acoustical pulses are emitted from a sending unit and are received by a reference acoustical transducer and by a slave acoustic transducer. The slave transducer emits a return pulse which is used to compute the duration of the sound propagation interval between the ends of the pipe. A phase angle compensation factor is computed by measuring the phase shift of the signal received by the reference transducer with respect to the signal emitted by the master transducer.

Abstract: Acoustic transponders are attached to sections of a submarine cable for use in accurately locating the cable during deployment or retrieval. An acoustic signal at one frequency, transmitted from the surface or elsewhere, stimulates one of the transponders to generate a first reply signal at a different frequency. The acoustic reply signal generated by each transponder is used to determine the location of that transponder and thus the location of its associated section of the cable. In order to measure cable tension during deployment or retrieval, a strain gauge at each transponder senses the tension of the cable at the location of its associated transponder. After each transponder transmits its first reply signal, it transmits a second reply signal delayed from the first reply signal by a time interval which is controlled by the output of its associated strain gauge.

Abstract: A quick deployment vehicle (QDV) for implanting a transponder or beacon on he ocean bottom in an upright position exposed for receiving or transmitting acoustic signals. The vehicle includes a ballistic body of separable fore and aft sections. The fore section includes a core mass for penetrating the ocean sediment, and the aft section includes a beacon for signal transmission. A predetermined interval after impact, as determined by a programmed deceleration profile stored in memory, the sections will separate. The sensed deceleration of the vehicle is compared at predetermined intervals to the stored profile, and when the sensed level is less than the stored level, a squib is fired to separate the two sections. The aft section penetrates and remains exposed above the sediment, while the fore section further penetrates into the ocean bottom.

Abstract: A pulse generator is provided for transmitting individual acoustic pulses which can be sensed by an audio surveillance device and retransmitted as modulated electromagnetic information. Circuitry is associated with the pulse generator for controlling the time when a first acoustic pulse is generated relative to the detection of an unmodulated carrier frequency. This circuitry further provides for the generation of a second acoustic pulse in the event that a modulated carrier frequency is detected during the interval when it can be expected that the first pulse has resulted in modulation of the previously unmodulated carrier frequency. Means are included in the circuitry for comparing the respective periods between the times the first and second acoustic pulses are generated and when modulation on the carrier frequency occurs within the predetermined intervals following such pulse generations.

Abstract: A distance R to be measured is derived by measuring the spacing x.sub.m between a fixed transmitter Tx and a movable receiver Rx, and comparing this with the reference spacing x.sub.ref between a fixed transmitter Tx' and receiver Rx. Each spacing is measured by passing a large number of pulses sequentially from receiver to transmitter through a coupling medium, the receipt of one pulse triggering transmission of the next. The spacing is derived from the time T taken to pass n pulses; preferably n is fixed and T is measured.

Abstract: An underwater photographic system which includes an underwater camera enclosure having an underwater sonar range-finding apparatus for providing a signal to adjust the distance-related parameters of a camera enclosed therein. The enclosure is adapted to house typically an unaltered commercially available self-developing or "instant" camera specifically including a camera having an air-sonar range-finding device.

Abstract: An ultrasonic communication system capable of wireless installation and supervised operation is achieved by communicating each information bit as two distinct ultrasonic frequencies separated in frequency enough to assure that the signal strength of both transmissions will not be in a deep null at the receiver location at the same time. The transmissions can be coded with a format that recognizes the correct data transmission even if reception of one frequency is lost. By use of transponders and other auxiliary units with periodic polling, supervised operation throughout a building can be maintained with events such as intrusion, fire or emergency as well as failures of particular units of the system reported.

Abstract: An acoustic distance measuring device using a predetermined frequency shift keyed bit pattern as the acoustic signal transmitted and received. A phase lock loop detector is provided. Variations in lag from the time required for the loop to lock are eliminated and the remainder of the FSK bit sequence is detected and accumulated in response to changes in the phase detector output. Preferably the FSK bit sequence is generated via radio frequency transmitter from a first location and reproduced and transmitted acoustically from a second station back to the first station.

Abstract: An acoustic system for covertly detecting surface to air missile (SAM) si by monitoring for noise emitted by the electrical power generated at the sites. The output of a microphone is sharply filtered around 75 Hz and a phase lock loop locks onto the signal and tracks slight deviations. By timing logic, signals of at least 7 minutes duration with interruptions of 10 seconds or less are considered SAM targets.

Abstract: A pulse generator is provided for transmitting an acoustic pulse which is sensed by an audio surveillance device and retransmitted as modulated electromagnetic information. Associated with the pulse generator is a timing arrangement and display. The timer is triggered into operation by the generation of the acoustic pulse. The operating speed of the timer is established to be a function of the speed of sound. Means are provided to stop the timer upon receipt of a demodulated signal representative of the retransmitted pulse whereby the display indicates the distance to the surveillance device.

Abstract: A beam of sound, of sufficient amplitude for inducing a finite amplitude effect in water, is directed into a field of sound for interaction therewith to produce intermodulation products. Energy is removed from the sound field in the formation of the intermodulation products resulting in an attenuation of sound in the sound field.

Abstract: In the measurement of the distance between two immersed points using ultrasonic signals, a control beacon is located at one point and a servo-beacon at the other point. The control beacon emits a first signal which is received by the servo-beacon. After a set period of time T sufficient for the disappearance of all echoes, the servo-beacon emits a signal which is received by the control beacon. Measurement apparatus associated with the control beacon determines the distance as a function of the time between emission of the first signal by the control beacon and reception of the signal from the servo-beacon, and the velocity of the ultrasonic signal which is determined in the region of the control beacon.

Abstract: A thin disk acoustic baffle comprising a thin disk of material having a uue combination of acoustical properties and dimensions to provide optimum attenuation of sound transmission between two points. Optimum sound attenuation is achieved by adjusting the thickness, diameter, and location of the thin disk relative to one of the points to be baffled and by selecting the material of the disk to have acoustic properties such that sound waves diffracted around the edges of the disk cancel the direct waves transmitted through the disk at a particular frequency of interest.

Abstract: 1. A masking-jamming sonar countermeasure system comprising in combination, receiver, a transmitter, a sequence timer connected between said receiver and said transmitter for regulating the operative time intervals thereof, and means coupled to the input of said transmitter for driving same with predetermined sonar signals and psuedo noise signals alternately applied thereto on a time-shared basis.

Abstract: A method of communicating with a remote precision transponder includes the step of transmitting first signals to the transponder. The first signals are received in the transponder, and second signals representative of the first signal are delayed therein for a precise time interval. After the precise time interval, third signals representative of the delayed second signals are transmitted from the transponder. Detailed embodiments of a transponder for performing these steps are also disclosed.

Abstract: 1. A helicopter destructor comprising in combination,a hydrophone channel,a microphone channel,a barometer channel,an AND gate connected to the outputs of said hydrophone, microphone, and ometer channels,an explosive means, andmeans connected to the outputs of said hydrophone channel and said AND gate for detonating said explosive means when a trio of signals are simultaneously applied to the respective inputs of said AND gate.

Abstract: 2. A method by which a submarine while deeply submerged in the sea may receive a message from a remote station without disclosing to others the position of the submarine, which comprises transmitting from said remote station into the atmosphere message information modulated on electromagnetic radiant energy, intercepting said radiant energy at a plurality of separated and widely dispersed relay stations on the surface of the sea, extracting the message information from the electromagnetic energy and transmitting acoustic wave energy modulated by said message information from each of said relay stations into the sea, locating said submerged submarine in message receiving range of one of said relay stations and detecting the acoustic wave energy modulated by the message information aboard said submarine.

Abstract: 1.

Abstract: Various types of rivercraft propelled by motor, poling, sculling or paddl are found to generate broadband noise having a superimposed low frequency sinusoidal modulation. To detect the presence of such craft, a hydrophone, tethered in a river from a moored subsurface float is connected to a concealed transmitter located on the bank. The detected audio signal is demodulated and filtered. When classification criteria have been satisfied, a gate opens allowing the demodulation information to be processed by a logic circuit, which, if satisfied, causes the hydroacoustic signal to be transmitted over an RF link to a remote receiver station.