Abstract: A pipeline instrumentation and control system comprising a first electrically insulated radiating cable for controlled radiation and reception of electromagnetic signaling carried to a second electrically insulated radiating cable wherein first and second electrically insulated radiating cables are axially disposed along a production well pipe and wherein first axially radiating cable comprises a section configured to substantially overlap second radiating cable section and further wherein electrical signals present in first radiating cable section is configured to induce a corresponding signal in said second radiating cable section to facilitate the transfer of electromagnetic radiation therebetween. The present invention provides reliable data communication from any location within the production system and improves reservoir management, well planning and resource exploitation.

Abstract: A signal coupling system for data and/or power signalling in a confined space such as in tubing within a hydrocarbon extraction well. First and second transceivers are arranged with primary and secondary loops lying orthogonal to the ends of the transceivers. The transceivers can be narrower for access to confined spaces. Each loop is housed in a semi-cylindrical housing with a planar face, so providing a cylindrical body when oppositely arranged for the transfer of electromagnetic radiation therebetween. Guiding surfaces are also provided on the housing to assist in bring the coupling system together in the confined space.

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 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 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 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 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 noise reducing near-field antenna comprising a first and second antenna section and a digital signal processor. The first antenna section detects the magnetic field component of an incident signal and the second antenna section detects the electric field component of an incident signal. The first antenna section outputs a signal to the digital signal processor comprising a wanted magnetic field component of a near-field incident signal and a magnetic field component of an unwanted far-field noise signal. The second antenna section outputs the electric field component of the unwanted noise signal to the digital signal processor. The digital signal processor determines the magnetic field component of the unwanted incident signal from the electrical field component thereof and subtracts this value from the received signal of the first antenna section, thereby removing the unwanted noise signal from the near-field received signal.

Abstract: The present invention relates to a transfer system for providing wireless data transfer, electrical power transfer and navigation between a mobile subsea vehicle and a deployed subsea station that uses acoustic and electromagnetic carrier signals for wireless communication and navigation. An inductive connector is provided for power transfer between mobile subsea vehicle and a deployed subsea station without conductive contact.

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: A transmit/receive antenna for transmission and reception of electromagnetic signals. The transmit/receive antenna comprises a TX section and an RX section, where the TX section comprises a magnetically coupled TX element and a TX input terminal and the RX section comprises at least one magnetically coupled RX element and has an RX output terminal. Axes of the TX loop element and the at least one magnetically coupled RX solenoid element are parallel. Moreover, the at least one magnetically coupled RX element is positioned to provide high isolation at the RX terminal of the antenna from TX electrical signals fed to the TX input. Specifically, the at least one magnetically coupled RX element is positioned at a so that the net magnetic flux generated by the TX loop element and threading the RX solenoid element is zero.

Abstract: The present invention provides a precision alignment system operable to provide alignment of a first and second apparatus. The precision alignment system makes use of inductive coupling between loop antennas in the first and second apparatus. The mechanism for alignment is the detection of a null in the signal induced in the loop antennas of the second apparatus arising from an input signal fed to a loop antenna of the first apparatus. The precision alignment system can be incorporated in a system for the wireless transfer of electrical power or may be incorporated in a system for the transfer of data. The precision alignment system of the present invention is particularly suited to applications where optical or other means for alignment of two apparatus are unreliable. In particular, the alignment system disclosed is suitable for operation underwater.

Abstract: A bipolar pulse forming transmission line module and system for linear induction accelerators having first, second, third, and fourth planar conductors which form a sequentially arranged interleaved stack having opposing first and second ends, with dielectric layers between the conductors. The first and second planar conductors are connected to each other at the first end, and the first and fourth planar conductors are connected to each other at the second end via a shorting plate. The third planar conductor is electrically connectable to a high voltage source, and an internal switch functions to short at the first end a high voltage from the third planar conductor to the fourth planar conductor to produce a bipolar pulse at the acceleration axis with a zero net time integral. Improved access to the switch is enabled by an aperture through the shorting plate and the proximity of the aperture to the switch.

Abstract: The present invention provides an underwater navigation system which can determine the bearing and the range of a remotely located beacon from a navigation station. The remotely located beacon transmits a pair of signals each having a different propagation velocity. Typically, the pair of signals are an acoustic signal and an electromagnetic signal. The range of the beacon to the navigation station is determined by a time differential in the detection of the two signals at the navigation station. The time differential is alternately a variation in phase between the two signals, or a time difference between the reception of a timing event encoded in synchronization on the pair of signals. In one form, the navigation station is a mobile unit which navigates to the remotely located beacon, and in another form the navigation station has a fixed position, and the remotely located beacon is mobile.