Abstract: An underwater remote sensing system comprising a transmitter for transmitting an electromagnetic signal, a receiver for receiving an electromagnetic signal reflected from an object and determining means for determining the location of the object, wherein at least one of the transmitter and receiver is underwater. The determining means may be operable to determine the location of the object using signals received at three or more receiver positions. To do this, three or more receiver antennas may be provided. Alternatively, a single receiver antenna may be provided and moved between three or more different measurement locations.

Abstract: An underwater navigation system comprising a transmitter having an electrically insulted magnetic coupled antenna for transmitting an electromagnetic and/or magneto-inductive signal, a receiver having an electrically insulated magnetic coupled antenna for receiving an electromagnetic and/or magneto-inductive signal from the transmitter, and determining means for determining the position of the receiver relative to the transmitter using the received electromagnetic and/or magneto-inductive signal.

Abstract: The present invention relates to an underwater guidance system for guiding an underwater apparatus, for example an underwater vehicle, towards a target structure, such as a docking station. The system comprises at least one system for capturing or sensing information on the relative position of the apparatus and the target structure and/or at least one imaging system for capturing an image of the target structure and a transmitter for wireless electromagnetic transmission of data indicative of the position information and/or captured image to the underwater apparatus or an underwater apparatus controller.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: The present invention relates to a connector system that provides the transfer of electrical power and/or data communications signals between two systems. The connector has no conductive electrical connection and can operate independently of angular orientation.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An antenna system, with a loop antenna and a loop current, is provided for transmitting an electromagnetic signal through a medium. The loop antenna has an E field transducer that generates an E field, and an H field transducer that generates an H field. The E and H fields are orthogonal in space and have at least one of a magnitude and phase relationship that is matched to an intrinsic impedance of a medium to generate a propagating wave. In an insulating medium the loop current lags an E field plate voltage by 90° to produce in phase E and H fields. In a conductive medium current is applied to the loop with a 135° phase lag with respect to a voltage across the E field plates. The H field is generated by the current component and leads current by 90°.

Abstract: A wearable article of clothing and the like is configured to be worn by a person underwater or underground; An antenna with at least one loop, is coupled to the wearable item. The antenna provides transmission or receipt of electromagnetic signals and has a size and geometry that maximizes antenna transmission area while minimizing a restriction on movement by the person wearing the wearable article. The antenna carries an alternating current that provides conductive attenuation and has three different field components. Each field component has a different geometric loss when moving a distance r from the antenna. R is a propagating distance from the antenna.

Abstract: An environmental monitoring system including at least one underwater measurement device and a transmitter for transmitting data from the measurement device to an above water station using a magnetically coupled antenna.

Abstract: A magnetic and/or magneto-electric antenna that has a plurality of conducting loops, two or more of the loops being driven by separate drivers, wherein the loops are positioned side by side in a net-like layout.

Abstract: A bidirectional asymmetric system is provided with a first node and a second node. The first node has a first transmitter that produces a modulated magnetic flux and a first exciter receiver that acts to receive data at the first node. The second node is coupled to the first node with a direct inductive communications downlink and a mutually inductive uplink. The second node includes a receiver that produces a signal induced by the first transmitter at the first node. The second node has a mutually inductive data transmitter that modules an exciter signal produced at the first node by the exciter receiver.

Abstract: A wearable article of clothing and the like is configured to be worn by a person underwater or underground; An antenna. with at least one loop, is coupled to the wearable item. The antenna provides transmission or receipt of electromagnetic signals and has a size and geometry that maximizes antenna transmission area while minimizing a restriction on movement by the person wearing the wearable article. The antenna carries an alternating current that provides conductive attenuation and has three different field components. Each field component has a different geometric loss when moving a distance r from the antenna. R is a propagating distance from the antenna.

Abstract: A transceiver antenna system comprising at least one solenoid receive antenna and at least one transmitting loop antenna, the at least one solenoid receive antenna being located with its axis in the plane of a transmitting loop antenna and located inside the loop.

Abstract: A magnetic and/or magneto-electric antenna that has a plurality of conducting loops that each can be resonated at a frequency that is offset from the other loops to provide a composite band-pass response that is broader than that of the individual loops.

Abstract: A magnetic and/or magneto-electric antenna is provided that has a plurality of conducting loops. Two or more of the loops are driven by separate drivers.

Abstract: A magnetic flux coupling transducer system comprising a primary coil (51) and primary coupling core (52) and a secondary coil (54) and secondary coupling core (55) for passing communications signals and/or electrical power from one side of an electrically conductive barrier to receiving equipment on the other side.

Abstract: An underwater connector (10) comprising a magnetic coupler for passing communications signals and/or power from one part (12) to another part (13) using magnetic coupling and without requiring direct electrically conductive contact between the parts (12, 13).

Abstract: A data communication system includes a transmitter. The transmitter transmits data in a digitally modulated electromagnetic or magnetic signal. A receiver is provided for receiving the digitally modulated electromagnetic or magnetic signal. At least one of the transmitter and receiver is below ground and has a magnetically coupled antenna.

Abstract: An underwater communication method is provided. EM signals are transmitted via a seabed using an underwater electrically insulated magnetically coupled antenna. By making use of the low loss properties of the seabed, EM signal attenuation can be reduced and consequently the transmission range can be increased. The underwater electrically insulated magnetically coupled antenna may be located within a body of water or may be buried in the seabed.

Abstract: An extended underwater electromagnetic transducer is provided with an electrically insulated transmission line typically connected to a transmitter or receiver or transceiver system. The transmission line allows near-field communications with another transmitter or receiver or transceiver system. The transmission line provided is relatively long, the through water signal path length can be significantly reduced.