Underwater communications

• US 8,134,890 B2
• Filed: 08/02/2007
• Issued: 03/13/2012
• Est. Priority Date: 08/03/2006
• Status: Expired due to Fees

• Current Assignee: Wfs Technologies Ltd.
• Original Assignee: Wfs Technologies Ltd.
• Inventors: Rhodes, Mark, Hyland, Brendan
• Primary Examiner(s): PIHULIC, DANIEL T
• Application Number:
  US12/373,010
• Publication Number:
  US 20090245025A1
• Time in Patent Office: 1,685 Days
• Field of Search: 367/134, 367/131, 367/128, 455/40, 738/65
• 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 in air at an above water station using low frequency electromagnetic and/or magnetic signals, and/or a receiver for receiving data and/or commands from a transmitter in air at the above water 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 measured data is modulated on the electromagnetic or magnetic signal.

3. A system as claimed in claim 1, further including a processor, the processor executing one or more command signals received by the underwater receiver from the above water station.

4. A system as claimed in claim 1, wherein the submerged 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 above water station.

5. A system as claimed in claim 4, wherein the pattern of transmission periods is capable of being changed by one or more command signals received at the submerged receiver from a remote location.

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

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

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

9. A system as claimed in claim 1, wherein the underwater 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 above water station.

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

11. A system as claimed in claim 10 wherein the omni-directional antenna comprises three orthogonal antennas.

12. 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.

13. A system as claimed in claim 1 wherein the transmitter is operable to transmit a signal to allow its underwater location to be determined.

14. A system as claimed in claim 13 wherein the position location signal is a regular operational signal or a signal sent as a result of a command for the purpose or a signal sent in response to one or more predetermined conditions detected by the measurement device.

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, including an intermediate relaying station.

17. 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 above-water location using a magnetically coupled antenna.

18. A sonde as claimed in claim 17 comprising a receiver for receiving low frequency electromagnetic or magnetic signals from the above-water location using a magnetically coupled antenna.

19. A sonde as claimed in claim 17 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.