UNDERWATER COMMUNICATIONS

• US 20120170417A1
• Filed: 03/12/2012
• Published: 07/05/2012
• Est. Priority Date: 08/03/2006
• Status: Active Grant

• Current Assignee: Wfs Technologies Ltd.
• Original Assignee: Wfs Technologies Ltd.
• Inventors: Rhodes, Mark, Hyland, Brendan
• Granted Patent: US 8,363,513 B2
• Time in Patent Office: Days
• US Class Current: 367/131
• CPC Class Codes: H01Q 1/04 Adaptation for subterranean or subaqueous use
• 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 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.

Claims

1. An environmental monitoring system comprising at least one underwater environmental measurement device and a transmitter for transmitting data from the measurement device in water to a receiver at an at least one intermediate relay station using low frequency electromagnetic and/or magnetic signals, and/or a receiver for receiving data and/or commands from a transmitter at the at least one intermediate relay station using low frequency electromagnetic and/or magnetic signals, wherein the transmitter and receiver include a magnetically coupled antenna.

2. A system as claimed in claim 1 wherein the intermediate relay station further comprises an environmental measuring device and a modem.

3. A system as claimed in claim 1 further comprising a cooperative station wherein the at least one intermediate relay station has a transmitter for transmitting data from the measurement device to a receiver at the cooperative station using low frequency electromagnetic and/or magnetic signals, and/or a receiver for receiving data and/or commands from a transmitter at the cooperative station using low frequency electromagnetic and/or magnetic signals, wherein the transmitter and receiver include a magnetically coupled antenna.

4. A system as claimed in claim 1 wherein measured data is modulated on the electromagnetic or magnetic signal.

5. A system as claimed in claim 3, further including a processor, the processor executing one or more command signals received by the underwater receiver from the cooperative station.

6. A system as claimed in claim 3, wherein the measurement device transmitter is operable intermittently according to a predetermined pattern of transmission periods or when instructed to be so operable by one or more command signals received by the underwater receiver from the cooperative station.

7. A system as claimed in claim 6, wherein the pattern of transmission periods is capable of being changed by one or more command signals received at the measurement device receiver from a remote location.

8. A system as claimed in claim 1, wherein the measurement receiver is operable substantially only during periods when a command signal might be expected periodically or according to a predetermined schedule.

9. A system as claimed in claim 1, wherein the transmitter is caused to transmit data as and when it becomes available.

10. A system as claimed in claim 1, wherein the measurement device is operable to report the condition of its battery supply periodically, or on a received command, or when the battery reaches a certain state of discharge.

11. A system as claimed in claim 3, wherein the measurement device is capable of performing a self-testing or assessment process on receipt of a command signal and transmitting the result of the process to the cooperative station.

12. A system as claimed in claim 1, wherein one or more of the antennas is omnidirectional.

13. A system as claimed in claim 12 wherein the omni-directional antenna comprises three orthogonal antennas.

14. A system as claimed in claim 1 further comprising a waterproof housing, wherein the measurement device and transmitter/receiver circuitry are included in the housing.

15. A system as claimed in claim 1 wherein the measurement device is operable to measure one or more of the following:

flow rate;

water depth by pressure sensing;

water depth by ultrasonic techniques;

temperature;

acidity/alkalinity (pH);

conductivity;

dissolved oxygen content;

chlorophyll density;

salinity and presence of chemicals such as ammonium salts and nitrates;

presence of other specific pollutants determined by chemical analysis sensors;

presence of blue-green and other potentially toxic algae;

particulate content; and

turbidity.

16. A system as claimed in claim 1, wherein the intermediate relaying station is submerged.

17. A system as claimed in claim 1 wherein the cooperative station is located above water.

18. A waterproof sonde comprising at least one sensor for sensing at least one environmental parameter, and a transmitter for transmitting low frequency electromagnetic and/or magnetic signals carrying data from the sensor to an intermediate relay located underwater using a magnetically coupled antenna.

19. A sonde as claimed in claim 18 comprising a receiver for receiving low frequency electromagnetic or magnetic signals from the above-water location using a magnetically coupled antenna.

20. A sonde as claimed in claim 18 wherein the sensor is operable to measure one or more of the following:

flow rate;

water depth by pressure sensing;

water depth by ultrasonic techniques;

temperature;

acidity/alkalinity (pH);

conductivity;

dissolved oxygen content;

chlorophyll density;

salinity and presence of chemicals such as ammonium salts and nitrates;

presence of other specific pollutants determined by chemical analysis sensors;

presence of blue-green and other potentially toxic algae;

particulate content; and

turbidity.