Distributed underwater electromagnetic communication system

• US 20070135044A1
• Filed: 01/24/2006
• Published: 06/14/2007
• Est. Priority Date: 12/14/2005
• Status: Active Grant

• Current Assignee: Wireless Fibre Systems
• Original Assignee: Wireless Fibre Systems
• Inventors: Hyland, Brendan, Rhodes, Mark, Wolfe, Derek
• Granted Patent: US 7,826,794 B2
• Time in Patent Office: Days
• US Class Current: 455/40
• CPC Class Codes: H04B 13/02 Transmission systems in which the medium consists of the earth or a large mass of water thereon, e.g. earth telegraphy

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.

Claims

1. An underwater system having a transmitter and/or receiver and an elongate transducer electrically insulated from the water and coupled to the transmitter and/or receiver for transmission and/or reception of electromagnetic signals, the transducer being operable to provide both local electromagnetic coupling to the underwater environment and conveyance of the electrical signal along its length to the transmitter and/or receiver.

2. An underwater system as claimed in claim 1, wherein the elongate transducer has a length that is more than the maximum distance over which underwater electromagnetic coupling can occur.

3. An underwater system as claimed in claim 1 or claim 2, wherein the elongate transducer is a coaxial cable that is adapted to couple electromagnetic energy to and from the underwater environment.

4. An underwater system as claimed in claim 1 or claim 2, wherein the transducer is an electrically insulated conductor cable that is adapted to couple electromagnetic energy to and from the underwater environment.

5. An underwater system as claimed in claim 1 or claim 2, wherein the transducer is an electrically insulated imbalanced twisted pair cable that is adapted to couple electromagnetic energy to and from the underwater environment.

6. An underwater system as claimed in any of the preceding claims wherein the elongate transducer and its associated transmitter and/or receiver are provided in a mobile station.

7. An underwater system as claimed in any of claims 1 to 6 wherein the elongate transducer and its associated transmitter and/or receiver are provided in a station that is located at a fixed position.

8. An underwater system as claimed in claim 7 wherein the elongate transducer is carried on a sub-water surface.

9. An underwater system as claimed in any of the preceding claims having two or more underwater stations, at least one including an elongate transducer electrically insulated from the water and coupled to a transmitter and/or receiver.

10. An underwater system as claimed in claim 9 wherein at least one of the stations is mobile.

11. An underwater system as claimed in any of the preceding claims wherein the elongate transducer is selectively extendible into an operational position as and when required.

12. An underwater system as claimed in any of the preceding claims that is part of a navigation system.

13. An underwater system as claimed in any of the preceding claims that is part of a communication system.