Abstract: A data communication system comprising a transmitter for transmitting an electromagnetic and/or magneto-electric signal, a receiver for receiving an electromagnetic and/or magneto-electric signal, and means for compensating for reducing or substantially eliminating signal dispersion, wherein at least one of the transmitter and receiver is underwater.

Abstract: The present invention provides an undersea seismic monitoring network, the monitoring network comprises at least one underwater vehicle and at least two monitoring stations located on the seabed, where each of the monitoring stations comprises at least one sensor for gathering seismic data and a radio modem for transmitting and receiving data to and from the underwater vehicle via a first wireless connection and where a second wireless connection is established between the monitoring stations, wherein the first wireless connection is formed by electromagnetic radiation through the water and the second wireless connection is formed by the propagation of an electromagnetic signal at least partially through the seabed.

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: 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: 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: 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: 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.

Abstract: An underwater inspection system comprising an underwater mobile inspection station (52) having an electromagnetic antenna (53), the mobile station (52) being adapted to capture inspection data and use the electromagnetic antenna (53) to send information relating to the inspection data to a underwater electromagnetic receiver that has a fixed electromagnetic antenna (55).

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: The present invention relates to a system that provides flexible data access to a wired underwater communications network through an electromagnetic, non-conductive connection. An underwater data access point is described wherein data access to a cabled network is provided through an electromagnetic connection. An inductive connector system may also be provided to allow transfer of data and/or power between a data access point and a client system.

Abstract: The present invention provides a wireless auxiliary system for monitoring and control of an underwater installation. The auxiliary system of the present invention sends data and control signals between an underwater installation—for example, a lower stack 26 in a hydrocarbon drilling or production facility—and an associated riser assembly 23. Data is collected by sensor network 208A, 208B and is transmitted from a first transceiver 201 to a second transceiver 203 by electromagnetic signals. First transceiver 201 is powered by a local power supply 205. To conserve power consumption, the first transceiver is designed to become active for a short time and then to switch to an inactive mode. For example, wireless data transfer may occur after the detachment or just prior to the reattachment of riser assembly 23 to the underwater installation. Wireless data transfer may also occur on receipt of a handshaking signal from second transceiver 203.

Abstract: An underwater detection system comprising: at least one transmitter (14) for transmitting electromagnetic and/or magneto-inductive signals through water; at least one receiver (15, 16); means for monitoring a signal received from the transmitter (14), and means for using the monitored signal both as a reference and to identify any change or changes in the received signal to infer the presence of an interposing object.

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 provides a system and apparatus for transferring electronic data and/or power from one station to another by means of a transportable pod comprising a solid state memory device and further provided with an inductively linked, electrically insulated connector. The transportable pod comprises a battery which is used to power a remote host docking station, which may be used in an underwater environment for the collection of subsea data. The transportable pod can be transferred alternately from a home docking station, where it is charged up, and where it's stored data is uploaded and to a remote host docking station where is provides power, and where it collects and stores data collected by the remote host docking station.

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: 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 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: 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: An underwater communication system comprising a transmitter for transmitting information using an electromagnetic and/or magneto-electric transmit antenna and a receiver for receiving information using an electromagnetic and/or magneto-electric receive antenna, at least one of the transmit and receive antennas comprising a plurality of antenna elements which collectively use field superposition and interference to form composite field patterns, beams or shapes and wherein one or both the transmit antenna and receive antenna are underwater.

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.