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 poin...

A method for reliably locating the position of a submerged submarine with spect to a surface ship. A multiple number of transponders are placed at known locations near the sea floor, in the area of the ship and the submarine. One transponder has a dual function both as a response transponder and as a relay transponder. The other transponders have a single function as response transponders. Elapsed times between transmission of a first acoustic transmission pulse from the ship and receptions of f...

A position and velocity determining system, that uses two functioned receiver-transmitters. In performing a first function, each receiver-transmitter transmits an acoustic pulse at a unique frequency, in response to a first received accoustic pulse. In performing a second function, each receiver-transmitter transmits a continuous acoustic signal at a unique frequency, in response to a second received acoustic pulse.

A system, apparatus, and method for determining positions of underwater animals involves emplacement of an acoustic transponder on the animal and establishing communications with a transponder carried by a vessel whose position can be determined by receiving signals from an external source such as a GPS satellite in order to establish proximity of the animal to the vessel, the position of the vessel then being adopted as the position of the animal. Communications can be established either by com...

An arrangement for determining the relative three dimensional positional relationship, including the horizontal separation, location, and orientation between a plurality of underwater transponders. A plurality of underwater transponders are positioned adjacent the bottom of the body of water and the number of the plurality of transponders for an unambiguous determination comprises at least three. In one embodiment, each of the transponders is provided with structure to receive a first interrogat...

A system for determining the position of a ship in relation to predetermined positions on the ocean floor is disclosed. A plurality of first acoustic addressable transponders and a plurality of second acoustic addressable transponders are respectively located at first and second sets of predetermined positions on the ocean floor. Each of the acoustic transponders transmits an acoustic ranging response and identification signal in response to receipt of an acoustic ranging interrogation signal. F...

A set of three or more acoustic transponders positioned below the surface of the ocean is provided with logic circuitry that enables location of transponder positions merely by listening to transponder signals and also enables location of an unknown receiving station merely by listening to transponder signals. The transponders are self-synchronizing to eliminate the need for precision timing over long periods. In a first mode, each transponder transmits a signal to the surface and retransmits up...

A two-way ultrasonic positioning and navigation system and method involve a plurality of objects each capable of transmitting and receiving ultrasonic signals. A first object transmits an initiating ultrasonic signal and identifies a second object for responding to the initiating ultrasonic signal. The second object transmits a responding ultrasonic signal after a predetermined time delay from receiving the initiating ultrasonic signal. The first objectives the responding ultrasonic signal, and ...

The three-dimensional position (geographic position and depth) of equipment towed underwater by a moving ship is continually and precisely monitored by an acoustic system that includes a network of underwater, acoustic transponders, and a remote, battery-powered, acoustic interrogation transducer that is associated with the suspended equipment. Initially a combination of satellite fixes of the ship's position and direct interrogation of the transponders from the ship are utilized by a shipboard ...

Apparatus and method for signaling within a drill bore hole without disturbing an ongoing drilling operation. Repeater stations are utilized at intervals along a drill string with the repeater input and output being in different noninterfering first and second modes. Furthermore, means are shown for causing successive repeater transmitters of any given mode to produce only negative feedback and hence to cause the overall system to be self-stabilizing. Special means are also shown for selectively...