HIGH-BANDWIDTH UNDERWATER DATA COMMUNICATION SYSTEM

• US 20140341584A1
• Filed: 03/10/2014
• Published: 11/20/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Magseis FF, LLC
• Original Assignee: Fairfield Industries Incorporated
• Inventors: Lacovara, Philip, Hopewell, William, Morris, Michael
• Granted Patent: US 9,490,911 B2
• Time in Patent Office: Days
• US Class Current: 398/104
• 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 method of performing seismic exploration in an aqueous medium, comprising:

receiving sub-aqueous environmental data of a first ocean bottom seismometer (OBS) unit disposed in the aqueous medium;

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 in the aqueous medium;

transmitting, by an optical transmitter of the OBS unit, the optical signal in the first format through the aqueous medium;

receiving, by an optical receiver of at least one of a remotely operated vehicle (ROV) and an autonomous underwater vehicle (AUV), the optical signal transmitted through the aqueous medium;

converting, by the at least one of the ROV and the AUV, the optical signal transmitted through the aqueous medium into a non-optical signal having a second format; and

transmitting the non-optical signal in the second format from the at least one of the ROV and the AUV to a marine vessel.

2. The method of claim 1, comprising:

converting the optical signal into the non-optical signal configured for wired transmission to a marine vessel; and

transmitting the non-optical signal to the marine vessel via a cable.

3. The method of claim 1, wherein the OBS unit is a first OBS unit, the optical signal is a first optical signal, comprising:

transmitting, by a second OBS unit to the first OBS unit, through the aqueous medium, a second optical signal based on sub-aqueous environmental data received via the second OBS unit; and

receiving, by the first OBS unit, the second optical signal for transmission to the at least one of the ROV and the AUV.

4. The method of claim 1, wherein the optical receiver includes a first optical transceiver, and the optical transmitter includes a second optical transceiver.

5. The method of claim 1, wherein the non-optical signal transmitted from the at least one of the ROV and the AUV to the marine vessel comprises an electrical signal, comprising:

transmitting, from the at least one of the ROV and the AUV, the electrical signal via a fiber optic cable to the marine vessel.

6. The method of claim 1, comprising:

determining, by at least one of the OBS unit, the ROV and the AUV, a characteristic of the aqueous medium; and

adjusting a parameter associated with the optical signal based on the characteristic of the aqueous medium.

7. The method of claim 6, wherein the characteristic comprises at least one of turbidity, a water quality, a water current, and an opacity.

8. The method of claim 6, 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 receiver.

9. The method of claim 1, comprising:

initiating an optical link between the OBS unit and the at least one of the ROV and the AUV;

transmitting, from the OBS unit to the at least one of the ROV and the AUV, a first optical signal having a first data rate;

determining that a bit error rate of the first signal satisfies a threshold; and

responsive to determining that the bit error rate satisfies the threshold, transmitting, from the OBS unit to the at least one of the ROV and the AUV, a second optical signal having a second data rate, the second data rate greater than the first data rate.

10. The method of claim 1, comprising:

initiating an optical link between the OBS unit and the at least one of the ROV and AUV;

transmitting, from the OBS unit to the at least one of the ROV and the AUV, a first optical signal having a first data rate;

determining that a bit error rate of the first signal does not satisfy a threshold; and

responsive to determining that the bit error rate does not satisfy the threshold, selecting a second data rate that is less than the first data rate; and

transmitting a second optical signal having the second data rate.

11. The method of claim 1, comprising:

initiating an optical link between the OBS unit and the at least one of the ROV and AUV;

transmitting, from the OBS unit to the at least one of the ROV and the AUV, a first optical signal having a first data rate;

determining that a bit error rate of the first signal does not satisfy a threshold; and

responsive to determining that the bit error rate does not satisfy the threshold, adjusting an automatic gain control.

12. The method of claim 1, comprising:

transmitting, by the OBS unit, the optical signal via at least one of a solid state light source, an InGaN based light source, a laser, and an LED.

13. The method of claim 1, comprising:

transmitting, by the OBS unit, data via the optical signal at a data rate of at least 10 Mbps.

14. The method of claim 1, comprising:

transmitting, by the OBS unit, the optical signal using a channel coding technique.

15. The method of claim 14, wherein the channel coding technique comprises at least one of an on-off keyed format, 8 b/10 b encoding, pulse-position discrimination, Quadrature Phase Shift Keying (QPSK), and Quadrature Amplitude Discrimination.

16. The method of claim 1, comprising:

transmitting, by the OBS unit, the optical signal using a multi-carrier transmission discrimination technique based on Orthogonal Frequency Division Multiplexing (OFDM).

17. The method of claim 1, wherein the sub-aqueous environmental data comprises data indicating at least one of seismic activity, dissolved solids in the aqueous medium, dissolved minerals in the aqueous medium, a state of the aqueous medium, oxygen concentration in the aqueous medium, salt concentration in the aqueous medium, plankton concentration in the aqueous medium, turbidity of the aqueous medium, and animal presence in the aqueous medium.

18. The method of claim 1, wherein the sub-aqueous environmental includes seismic data, comprising:

receiving the seismic data using a geophone of a first ocean bottom seismometer (OBS) unit disposed in the aqueous medium.

19. The method of claim 1, wherein the OBS unit is a first OBS unit, comprising:

receiving, by an optical receiver of a second OBS unit, from the first OBS unit, the optical signal;

transmitting, by an optical transmitted of the second OBS unit, the optical signal to at least one of the ROV and the AUV.

20. The method of claim 1, wherein the sub-aqueous environmental includes seismic data, comprising:

receiving the seismic data using an accelerometer disposed in the OBS unit.

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

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

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

an optical transmitter of the OBS unit configured to transmit the optical signal in the first format through the aqueous medium;

an optical receiver of at least one of a remotely operated vehicle (ROV) and an autonomous underwater vehicle (AUV) configured to receive the optical signal transmitted through the aqueous medium;

a second data conversion module of the at least one of the ROV and the AUV configured to convert the optical signal transmitted through the aqueous medium into a non-optical signal having a second format; and

a transmitter of the at least one of the ROV and the AUV configured to transmit the non-optical signal in the second format from the at least one of the ROV and the AUV to a marine vessel.