Abstract: A system for acoustically positioning a noisy platform. An array of transponders, adapted to be deployed in a region of water, is provided. A transducer is mounted on the noisy platform and another transducer is mounted on a relatively quiet vehicle tethered to the platform. A first means is provided for transmitting acoustical energy from the transducer on the noisy platform to said array and from said array to said transducer on said vehicle for measuring the distance from said noisy platform to said quiet vehicle via said transponders in said array. A second means is provided for transmitting acoustical energy from the transducer on said vehicle to said array and back to said vehicle for measuring the distance said vehicle is from the transponders in said array. Calculating means is coupled to said first and second means for determining the location of said noisy platform relative to said array.

Abstract: A method for determining the position of a marine seismic receiver cable of the type which is towed behind a seismic survey vessel through the sea, wherein the azimuth and the distance from the vessel to points along the seismic receiver cable are measured, and the coodinates of these points are calculated on the basis of these values. A hydroacoustic measurement method is utilized, based on a super-short baseline system integrated with a gyrocompass, for measuring the azimuth and distances in accordance with signals from transponders, beacons, responders and/or similar instruments installed on or within the seismic receiver cable.

Abstract: A system for monitoring the safety and location of individuals includes a portable transceiver worn by each individual and a base control unit for sending interrogation signals to the individual units. The interrogation signals are transmitted through both air and water, and the individual units transmit a response through the medium through which the interrogation signal was received. The base unit measures both the elapsed time from transmission to reception and the incoming phase angles of the response signal, and converts these measurements to indications of distance and angle between the base unit and the individual transceivers.

Abstract: An underwater fuel transfer system for the transfer of liquid fuels such as crude oil from an off-shore underwater mooring to a submerged submarine oil tanker. There is provided a berthing guidance and control system including permanently moored acostic transponders interrogated by the tanker sonar equipment to provide input commands for azmith control along the on-tack position in conjunction with speed controls. The system also includes an arrestor mooring apparatus for decelerating the tanker as the tanker approaches the underwater station. This underwater station has the dual function use of providing mooring for the tanker and also reception of the tanker oil transfer device.

Abstract: A system for deploying an array of sonar projector transducers includes a housing in which a plurality of disk shaped projectors are stacked, a pair of small diameter cables are reeled from a powered drum for tethering the projectors, the cables being anchored to the bottom projector, a pair of electrical conductors are connected to the projectors, each conductor constituting a series of sections interconnecting electrical connectors fastened to opposite sides of each projector, a centering ring attached to the bottom projector including a series of pressure responsive latches which serve to secure the array in the housing and to release the array upon its reaching a desired depth. Where the drum is actuated the stack is lowered with each projector being successively suspended by its pair of conductor sections, and each of the conductor sections is given a predetermined twist such that when the array is again returned to the housing the conductor sections are caused to form predetermined loops.

Abstract: A method is disclosed for locating the position of a marine streamer using two boats and a series of transponders in the streamer. A first pulse is electrically triggered and then generated by the transponders and by a transceiver mounted in the seismic vessel that tows the streamer. These first pulses are detected at a slave ship and the respective distances to the acoustic sources are calculated. The actual locations of the streamer transponders are calculated by trilateration when a second pulse from transponders 2-5 is detected at the slave ship. This second pulse is an acoustically triggered product of an electrically triggered initial pulse generated by a first transponder. This acoustically triggered pulse is used to determine the distance from the seismic ship to the transponder nearest the seismic ship and then to successively further transponders down the streamer length. Thereafter the positions of the transponders may be calculated.

Abstract: Method and means are provided for determining the position of a submerged marine streamer towed behind an exploration vessel. An array of sets of at least three transponders secured to the ocean floor generate distinguishable acoustic pulses upon a command signal. These signals are received by receivers housed in the streamer. The position to each receiver may be triangulated from the data generated.

Abstract: A method of and a system for remote control of individual electronic equipments which are spread out across a large geographical area. Particularly activation of radio transmitters spread over the water surface and cooperating with hydrophones for picking up sound waves from submarines in order to locate submarines. To selectively activate the electronic equipments electromagnetic waves or sound waves are transmitted with given relative time positions from at least three fixed stations having known geographical positions. In each electronic equipment the waves are received and compared as regards their relative time positions at reception, activation of an equipment taking place only if a given criterion as regards said mutual time positions is fulfilled. Activation of equipments will take place only within a given small zone of said large area. The location of said small zone is determined by the relative time positions of the transmitted waves, which can be varied in order to select different zones.

Abstract: Acoustic distance measuring apparatus for measuring the distance of a vessel (N) from a vertical line through a fixed point (P) on the bottom of a body of water, the apparatus comprising: an acoustic emitter unit (I) and at least three acoustic receiver units (H1, H2, H3) disposed on the bottom of the vessel, said receiver units being disposed at the vertices of a plane polygon; at least three acoustic emitter/receiver units (A, B, C) placed on the water bottom in the vicinity of said fixed point (P), said emitter/receiver units being disposed at the vertices of a polygon; and the improvement wherein the measuring apparatus further includes a relay acoustic emitter/receiver (R) submerged close to the vessel at a depth where vessel noise is highly attenuated, said relay receiing acoustic waves (a) from the vessel's emitter and responding by emitting acoustic wave (1, 2, 3) to the vessel's receiver units thereby enabling the distances between the relay and each of the vessel's receiver units to be calculated, s

Abstract: Method and means are provided for determining the position of a submerged marine streamer towed behind an exploration vessel. An array of at least three transponders secured to the ocean floor generate distinguishable acoustic pulses upon a command signal from the ship. These signals are received by hydrophones housed in the streamer and by the ship. The distance to each hydrophone may be triangulated from the data generated including accounting for changes in velocity between the vessel and the seismic streamer and the bottom transponders during the taking of such data.

Abstract: A system and method for determining the position of towed marine object relative to a towing vessel. The system comprises a towing vessel, a slave vessel, and the towed object. An acoustic transceiver is located on either the towing vessel or the slave vessel with an acoustic receiver located on the other vessel. One or more acoustic transponders are associated with the towed object. The distance between the towing vessel and the slave vessel is determined, for example, by radio navigation which is calibrated by a high precision range-range system. The acoustic transmitter emits an interrogation signal which causes the transducer(s) to emit a response acoustic signal which is recorded at the two receivers. Using the time for the response signal to reach each of the receivers and the velocity of sound in water, the distance of the transducer from each vessel is calculated. With the three distances the location of the transducer relative to the towing vessel is determined by trilateration.

Abstract: Acoustic positioning device for a vessel comprising N transponders (B.sub.1 . . . B.sub.i . . . B.sub.N).A fixed acoustic transmitting means (E) periodically transmits acoustic pulses at frequency f. The responses of the transponders (B.sub.1 . . . B.sub.i . . . B.sub.N) are received by the acoustic array (A.sub.1, A.sub.2) of the vessels. The time origins are transmitted by a radio antenna to the surface vessel. In the case of submarines, two stable clocks are used, one of which is on board the submarine. Processing circuits make it possible to know the position of submarines.Application to the positioning of vessels in an oil production field or for oceanographic research.

Abstract: An acoustic positioning system for locating a marine cable at an exploration site employs a plurality of acoustic transponders, each having a characteristic frequency, at spaced-apart positions along the cable. A marine vessel measures the depth to the transponders as the vessel passes over the cable and measures the slant range from the vessel to each of the acoustic transponders as the vessel travels in a parallel and horizontally offset path to the cable.

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: Apparatus for monitoring cable tension during submarine laying operations is housed in a separable case suitable for nondestructive attachment around the circumference of a cable at any desired location prior to laying. A strain gauge within the housing is positioned in a saddle across which the cable is placed in a bowed state. The electrical output from the strain gauge, which is proportional to tension in the cable, is translated into an acoustical signal transmissible through a submarine environment. The underwater sound can be picked up by the laying vessel or an assist vessel and displayed in real time. A plurality of tension monitors can be interrogated in sequence or at random under the control of transponder signals from the vessel. The monitor is self-powered and requires no metallic electrical connection to the cable or to the laying vessel.

Abstract: A lift truck (16) carries a leftwardly directed ultrasonic receiver (32L) and a rightwardly directed ultrasonic receiver (32R) and an RF transmitter (34). Upon depositing its load in an assigned bin in a warehouse (FIG. 1), a load sensor (22) is actuated to cause transmission of a coded signal as to lift height and vehicle identification to a central station (60). This initiates a vehicle search by energizing ultrasonic transmitters (42-52). The ultrasonic receivers (32L and 32R) on a vehicle in a path under surveillance detect the sonic signal and relay this to the central station by way of the RF transmitter (34). The time duration which elapsed from energization of the ultrasonic transmitter to detection of the sonic signal is used to measure vehicle path depth and a comparison of the magnitudes of the sonic signals received by the receivers (32L and 32R) indicates the heading direction of the vehicle.

Abstract: The invention concerns acoustic under-water measurement apparatus for determining the location with respect to a surface vessel of objects such as submersible vessels, pipe-riders, mining apparatus, or the like, including tethered submersible vessels. A receiver hydrophone set located on the tethered vehicle receives acoustic reply pulses from sea bottom transponders, telemetering the times of reception to a surface support ship via conductors in the tether cable. Signals obtained at the surface ship directly from the transponders and indirectly via the tether cable conductors are combined aboard the surface ship for computing the positions of both vessels with respect to a base line established by the sea bottom transponders. The system is self-calibrating, so that an expensive survey to determine the actual locations of the bottom transponders is no longer required.

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.