Abstract: A light source unit irradiates a gas cell disposed in a measurement region with linearly polarized light in which the direction of travel is a z-axis direction and the vibration direction of an electric field is a y-axis direction. A polarimeter detects optical characteristics of light passing through the gas cell. A magnetic field generator applies an artificial magnetic field, capable of varying an x-axis component, a y-axis component, and a z-axis component, to the measurement region. A calculation control unit generates a plurality of artificial magnetic fields, calculates a magnetization value or a value corresponding to the magnetization value on the basis of the detection results of the polarimeter, and calculates an original magnetic field present in the measurement region, using an artificial magnetic field when the magnetization value or the value corresponding to the magnetization value satisfies a condition for external value.

Abstract: A card reader may include a card insertion slot into which the card is inserted; a metal detecting mechanism structured to detect the external connection terminal of the card inserted into the card insertion slot; a jamming magnetic field generation mechanism structured to generate a magnetic field for prevention of fraudulently reading a magnetic datum recorded in the magnetic stripe; and a control unit. The metal detecting mechanism may include an exciting coil and a detecting coil. The jamming magnetic field generation mechanism may include a jamming magnetic field generating coil. The control unit may be structured to alternately switch between a current supply to the exciting coil and a current supply to the jamming magnetic field generation coil, and detect the external connection terminal on the basis of an output from the detecting coil at a time when the exciting coil is supplied with a current.

Abstract: An electric field sensor for underwater, including a sensing unit that senses a change in an electric field and transfers a sensing signal of the electric field to a signal line, a waterproof sealing unit that keeps a signal transferring portion of the sensing unit in a waterproof state, and a water-passing protection unit that shields and protects an exposed portion of the sensing unit. The sensing unit includes a nonconductive hollow pipe connected to the signal line, a sheet of carbon fiber that is wound around the outer surface of the hollow pipe and that senses an electric field, and a terminal ring that is electrically conductively installed at an end portion of the sheet of carbon fiber to provide a connection portion of the signal line and that is watertightly sealed by the waterproof sealing unit.

Abstract: An apparatus that amplifies a signal, includes an amplifier configured to amplify the signal. The apparatus further includes a current supplier configured to supply a periodically variable current to the amplifier.

Abstract: A magnetic field measurement apparatus includes an irradiation portion, a gas cell, a measurement unit (polarization separation unit, light receiving portion, signal processing circuit), and a magnetic shield. The magnetic shield is formed in a elongated hollow shape having openings at both sides thereof. The gas cell, in which gaseous atoms are sealed, is disposed in a hollow area of the magnetic shield. The irradiation portion irradiates irradiation light including linearly polarized light adjusted so that the vibration direction of an electric field coincides with the axis direction of the magnetic shield onto the gaseous atoms sealed in the gas cell along a direction perpendicular to the axis of the magnetic shield. The measurement unit measures a rotational angle of a polarization plane of the irradiation light that has been irradiated by the irradiation portion and passed through the gaseous atoms.

Abstract: An underwater intelligence gathering weapon system accurately places a weapon underwater and then communicates therewith from other platform(s). The weapon is equipped to maneuver through the air to a destination at the water's surface. A first transceiver, mounted onboard the weapon and coupled to the mine's logic portion, is activated after the weapon is in the water. The first transceiver can send and receive magneto-inductive signals. A second transceiver that sends and receives magneto-inductive signals is remotely located with respect to the first transceiver. Once deployed, the weapon can be controlled from a safe distance and can report any intelligence information collected by onboard sensors.

Abstract: A vehicle is towed underwater by an air traveling helicopter through a towing cable to induce powered rotation of impellers on the vehicle during its underwater travel at a preselected seawater depth. An electrical generator driven by such impeller supplies electrical energy conditioned to produce a sternwise extending signature simulating magnetic field which is effective to detonate a sea mine in the underwater vicinity toward which the underwater vehicle is being towed.

Abstract: A limpet and method for control thereof have a receiver section responsive o magneto-inductive signals in the ELF to VLF range that arm and fire a main charge. A swimmer places the limpet and enables it for control by remotely transmitted magneto-inductive signals in the ELF to VLF range. ELF to VLF frequencies provide safe and reliable communications from a remote control platform such as a land-based command station, an aircraft, surface craft, or submarine. The appropriately coded magneto-inductive signals in the ELF to VLF range are transmitted through the sea, air, beach, buildings, vegetation and sediment or any combination of these conditions to arm and fire or disarm the limpet as called for in the battle plan.

Abstract: A desensitized firing circuit has a pair of diodes, a resistor, and a sevble wire loop used in combination with an existing firing circuit. With the severable wire loop intact, current flow through the resistor is shunted to ground, and the circuit operates in a sensitive mode. With the loop severed, current flows through the resistor and one of the diodes to the base of an input switching transistor, thereby maintaining this transistor in a conductive state until a sufficiently large and properly shaped negative input signal is received.

Abstract: An active electromagnetic influence firing system has transmitter coils and eceiver coils mounted on a single warhead section. One set of receiver coils has vertical look capability for detecting surface ships and another set has 360.degree. look capability for detecting submarines. An influence electronics package automatically nulls out directly induced electromagnetic radiation and passes only the signature received from targets. Amplitude, duration, and frequency criteria implemented by circuitry in the influence electronics package determine whether there is a valid target.

Abstract: A magnetometer is desclosed in which a gas cell containing atomic vapor is pulse pumped at one of the transitions of the gas in the cell. After the pulse has passed through the gas cell, thereby causing alignment of all the individual atomic moments along the propagation direction of the pulse, a probe beam reads out the Larmor precession frequency of the freely precessing atoms in terms of the frequency of the amplitude modulation of the probe beam caused by the free precession within the gas cell. The system is suitable for laboratory measurements of the absolute value of a magnetic field and for packaging in an expendable battery powered water-born buoy becuase of the low power consumption of the subject system.

Abstract: A control system for a magentic submarine mine adapted to be fired automaally upon the approach of a vessel and in which the possibility of premature detonation of the mine by a minesweeper is substantially reduced. For example, some of the magnetic mines being laid in a particular mine field may be set so that after several actuations by a minesweeper a few of the mines will be exploded, the remaining mine field requiring a larger number of signals before detonation. By varying the number of signals before a mine is detonated the particular mine field after being swept is still considered lethal because many of the mines are left in the armed condition and others awaiting to be armed by subsequent minesweeping or the passage of vessels, as the case may be.

Abstract: A firing circuit for a magnetic mine including an oscillator and magnetomr bridge is arranged to produce an alternating signal representative of the strength of the ambient magnetic field in the neighborhood of the mine. This signal after rectification and filtering is differentiated to produce a comparatively small direct current signal representative of the rate of change of the surrounding magnetic field. After amplification the signal is in turn applied to a pair of parallel gas tube channels designed to be fired in response to increases and decreases respectively of the signal, and the outputs of the two gas tube channels are retained and combined. A final output circuit is adapted to be fired in response to a predetermined output of the combining network.

Abstract: A buoy mooring device and system adapted to maintain a buoy in an upright untilted position. A rigid bail having a center of curvature essentially coincident with the buoy center of buoyancy is connected to the bottom of the buoy. A mooring line having an anchor on one end is attached on the other end to the bail by a movable connecting means. As wind and/or water currents tend to tilt the buoy, the mooring system maintains the buoy in an upright position. Alternative embodiments include mooring systems comprising foldable bails and systems comprising multiple bails.

Abstract: A smart mine includes a pair of He.sup.3 magnetic sensors exteriorly connected to a head compartment of a mine housing. A torpedo compartment for housing a torpedo completes the mine housing. The head compartment contains the sensor support electronics which includes a phase locked loop means having a pair of digital phase locked loops connected between the sensors and a difference circuit whereby a difference signal representative of the difference between the pair of He.sup.3 magnetic sensors is produced for processing in a signal processor for determining the presence of large ferromagnetic bodies and producing a torpedo firing signal.

Abstract: A warhead assembly having an explosive core and a surrounding annular package with several circumferential rows of different sized preformed fragments or rods. In each of one or more row, the fragments are alternately inverted keystone shapes arranged in a circle, with the adjacent sides fitting against each other in essentially pressure-confining contact. Further, the fragments which have their wider sides facing radially outward are composed of much higher density metal than the alternating fragments having their wider sides facing inward. This causes the lower density fragments to push the higher density fragments out at a high velocity when exploded.

Abstract: A device for underwater missiles for use against submerged submarines, said missiles including a housing (1) having a front portion, intended to contact the outside surface of a submarine. According to the invention, a tubular ring member (6) is rotatably attached to the front portion of the housing (1), said ring member (6) being arranged to take up a rotary movement in relation to the housing (1) when contacting the outside surface of a submarine. In order to facilitate rapid acceleration of the ring member (6) into said rotary movement, the ring member (6) is attached to the housing (1) by means of a ball bearing joint (7) or any other known low-frictional rotary joint or connection, and the mass of the ring member (6) is also considerably smaller than the total mass of the missile. The outer surface(s) of the ring member (6) is/are also preferably arranged with means intended to increase the frictional contact between the ring member (6) and the outer surface of a submarine on impact, e.g.

Abstract: An underwater missile for use against submerged submarines has a missile housing with a magnetic contact surface (2) at a foremost end portion intended to contact a submerged submarine. The magnetic contact surface is provided by two magnets (2',2") located in adjacency and with reversed magnetic polarity. A magnetically operated switching means (5) is positioned adjacent to the magnetic leakage field of the magnets, and is arranged to be operated when the leakage field is increased by means of a metallic object located within the magnetic field of the magnets. The operation of the switching means first detonates a small propellant charge (6) to impose a force to cause complete adherence between the magnetic contact surface of the missile and the outer surface of a contacted submarine, and then detonates a main explosive charge (7) intended to penetrate the submarine.

Abstract: A digital circuit for sensing peaks exceeding a predetermined threshold in nalog signals employs clock and control oscillators arranged such that their frequencies vary in opposite senses in response to changes in the sensed signal. The clock oscillator frequency is counted during sample intervals of durations which vary inversely with the control oscillator frequency. A count increase (or decrease) of predetermined amount from one sample interval to the next, followed by a count decrease (or increase) from another sample interval to the next, results in an output signal. In a preferred embodiment, the clock frequency is counted in an up/down counter which, for each sample interval, is counted up and down for equal numbers of control oscillator cycles. The net count at the end of a sample interval is therefore an indication of the magnitude and polarity of changes in the sensed signal.