High-bandwidth underwater data communication system

• US 9,825,713 B2
• Filed: 08/15/2016
• Issued: 11/21/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Magseis FF, LLC
• Original Assignee: Fairfield Industries Incorporated
• Inventors: Hopewell, William, Lacovara, Philip, Morris, Michael
• Primary Examiner(s): Jacob, Oommen
• Application Number:
  US15/237,106
• Publication Number:
  US 20160352436A1
• Time in Patent Office: 463 Days
• Field of Search: 398104, 398105
• CPC Class Codes: H03G 3/3084 in receivers or transmitters for electromagnetic waves other than radiowaves, e.g. lightwaves H03G3/32, H03G3/34 take precedence
• CPC Class Codes: H04B 10/2575 Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier
• CPC Class Codes: H04B 10/50 Transmitters
• CPC Class Codes: H04B 10/564 Power control
• CPC Class Codes: H04B 10/80 Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water
• 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
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/2697 in combination with other modulation techniques

Abstract

An apparatus is described which uses directly modulated InGaN Light-Emitting Diodes (LEDs) or InGaN lasers as the transmitters for an underwater data-communication device. The receiver uses automatic gain control to facilitate performance of the apparatus over a wide-range of distances and water turbidities.

Claims

1. A system to perform seismic exploration in an aqueous medium, comprising:

an ocean bottom seismometer (OBS) unit disposed in the aqueous medium to receive sub-aqueous environmental data;

a data conversion module of the OBS unit to convert the sub-aqueous environmental data into an optical signal with a first format configured for optical transmission via the aqueous medium;

at least one of the OBS unit and an underwater vehicle to;

establish, between the OBS unit and the underwater vehicle separated from the OBS unit by the aqueous medium, an optical link through the aqueous medium; and

determine a condition of the aqueous medium from a measurement of a characteristic of the optical link;

a controller of the OBS unit to adjust a parameter associated with the optical signal based on the characteristic of the aqueous medium;

an optical transmitter of the OBS unit to transmit, via the optical link, the optical signal to an optical receiver of the underwater vehicle, the optical signal comprising the first format and the parameter adjusted by the OBS unit based on the characteristic of the aqueous medium;

the underwater vehicle to;

receive the optical signal transmitted by the optical transmitter of the OBS unit via the optical link through the aqueous medium;

convert, responsive to receipt of the optical signal, the optical signal into a non-optical signal comprising a second format; and

provide the non-optical signal in the second format to a retrieval device.

2. The system of claim 1, comprising:

the retrieval device provided on a marine vessel.

3. The system of claim 1, comprising:

a cable,

wherein the underwater vehicle is further configured to provide the non-optical signal to the retrieval device.

4. The system of claim 1, comprising:

the optical receiver of the underwater vehicle further configured to sense an angle of the optical transmitter of the OBS unit; and

the underwater vehicle configured to select, based on a signal from the angle sensed by the optical receiver, an anode in a multiple-anode photomultiplier tube to align an angular field of view of the optical receiver with the optical transmitter.

5. The system of claim 1, comprising:

a photodiode of the optical receiver of the underwater vehicle to generate the non-optical signal comprising an electrical output based on light received by the optical receiver from the optical transmitter of the OBS unit; and

an automatic gain control amplifier of the underwater vehicle to adjust a level of the electrical output.

6. The system of claim 1, comprising the OBS unit configured to:

detect a presence of the underwater vehicle; and

enter a power up state responsive to the detection to transmit the optical signal.

7. The system of claim 1, comprising:

an optical transmitter of the OBS unit to enter, responsive to detection of a presence of the underwater vehicle, a power up state to transmit the optical signal,

wherein the OBS unit is further configured to validate, responsive to the power up state, the optical link prior to transmission of the optical signal.

8. The system of claim 1, wherein the optical transmitter is enclosed in a waterproof contained, and the optical transmitter comprises a solid state light source.

9. The system of claim 1, comprising the OBS unit configured to:

dynamically adjust the parameter in response one or more measurements of the characteristic of the optical link.

10. The system of claim 1, wherein the parameter comprises at least one of a data rate of the optical signal, an output intensity of the optical signal, a wavelength of the optical signal, and a gain of the optical receiver.

11. A method of performing seismic exploration in an aqueous medium, comprising:

receiving, by an ocean bottom seismometer (OBS) unit disposed in the aqueous medium, sub-aqueous environmental data;

converting, by a data conversion module of the OBS unit, the sub-aqueous environmental data into an optical signal having a first format configured for optical transmission via the aqueous medium;

establishing, between the OBS unit and an underwater vehicle separated from the OBS unit by the aqueous medium, an optical link through the aqueous medium;

determining, by at least one of the OBS unit and the underwater vehicle, a condition of the aqueous medium by measuring a characteristic of the optical link;

adjusting, by the OBS unit, a parameter associated with the optical signal based on the characteristic of the aqueous medium;

transmitting, by an optical transmitter of the OBS unit via the optical link, the optical signal to an optical receiver of the underwater vehicle, the optical signal comprising the first format and the parameter adjusted by the OBS unit based on the characteristic of the aqueous medium;

receiving, by the optical receiver of the underwater vehicle, the optical signal transmitted by the optical transmitter of the OBS unit via the optical link through the aqueous medium;

converting, by the underwater vehicle responsive to receiving the optical signal, the optical signal into a non-optical signal comprising a second format; and

providing, by the underwater vehicle, the non-optical signal in the second format to a retrieval device.

12. The method of claim 11, comprising:

providing the retrieval device on a marine vessel.

13. The method of claim 11, comprising:

providing, by the underwater vehicle via a cable, the non-optical signal to the retrieval device.

14. The method of claim 11, comprising:

sensing, by the optical receiver of the underwater vehicle, an angle of the optical transmitter of the OBS unit; and

selecting, by the underwater vehicle, based on a signal from the angle sensed by the optical receiver, an anode in a multiple-anode photomultiplier tube to align an angular field of view of the optical receiver with the optical transmitter.

15. The method of claim 11, comprising:

generating, by a photodiode of the optical receiver of the underwater vehicle, the non-optical signal comprising an electrical output based on light received by the optical receiver from the optical transmitter of the OBS unit; and

adjusting, by an automatic gain control amplifier of the underwater vehicle, a level of the electrical output.

16. The method of claim 11, comprising:

detecting, by the OBS unit, a presence of the underwater vehicle; and

entering, by the optical transmitter of the OBS unit, a power up state responsive to the detection to transmit the optical signal.

17. The method of claim 11, comprising:

detecting, by the OBS unit, a presence of the underwater vehicle;

entering, by the optical transmitter of the OBS unit, a power up state responsive to the detection to transmit the optical signal; and

validating, responsive to entering the power up state, the optical link prior to transmitting the optical signal.

18. The method of claim 11, wherein the optical transmitter is enclosed in a waterproof contained, and the optical transmitter comprises a solid state light source.

19. The method of claim 11, comprising:

dynamically adjusting, by the OBS unit, the parameter in response measuring the characteristic of the optical link.

20. The method of claim 11, wherein the parameter comprises at least one of a data rate of the optical signal, an output intensity of the optical signal, a wavelength of the optical signal, and a gain of the optical receiver.