Mobile underwater arrays

• US 5,894,450 A
• Filed: 04/15/1997
• Issued: 04/13/1999
• Est. Priority Date: 04/15/1997
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Schmidt, Henrik, Bellingham, James G., Bales, James W.
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US08/843,355
• Time in Patent Office: 728 Days
• Field of Search: 367/131, 367/133, 367/134, 367/117, 367/910
• US Class Current: 367/134
• CPC Class Codes: G01V 1/3817 Positioning of seismic devices
• 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 oceanographic sampling system includes two or more underwater vehicles disposed in an array and an array controller for controlling the array of underwater vehicles as data is acquired. Each underwater vehicle includes a propulsion system for moving the underwater vehicle independently of the other underwater vehicles, a sensor for sensing an ocean parameter and providing sensor data representative of the ocean parameter as the underwater vehicle moves, a navigation subsystem for determining position data representative of the position of the underwater vehicle as the sensor data is acquired and a synchronizing subsystem for time synchronizing the sensor data and the position data acquired by the underwater vehicle with sensor data and position data acquired by other underwater vehicles. The array of underwater vehicles may function as a large aperture phased array, and phased array analysis techniques may be applied to the time-synchronized sensor data and position data.

Claims

1. An oceanographic sampling system comprising:

a plurality of underwater vehicles disposed in an array having an array configuration, each underwater vehicle including a propulsion system for moving said underwater vehicle independently of other ones of said underwater vehicles, a sensor for sensing an ocean parameter and providing sensor data representative of the ocean parameter, a navigation subsystem for determining relative position data representative of the position of said underwater vehicle relative to other ones of said underwater vehicles as said sensor data is acquired and a synchronizing subsystem for time synchronizing the sensor data and the relative position data acquired by said underwater vehicle with sensor data and relative position data acquired by other ones of said underwater vehicles; and

array control means for controlling said array of said underwater vehicles as said time-synchronized sensor data and relative position data are acquired, wherein said control means comprises means for controlling operation of said array of underwater vehicles as a unit such that said underwater vehicles acquire array data sets containing information that is not present in the sensor data from individual ones of said underwater vehicles.

2. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for controlling said array configuration.

3. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for controlling movement of said array.

4. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for controlling a function of one or more of said plurality of underwater vehicles.

5. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for controlling said array in a preprogrammed manner.

6. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for adaptively controlling said array in response to a condition determined during acquisition of said sensor data.

7. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for adaptively controlling said array in response to said sensor data.

8. An oceanographic sampling system as defined in claim 1, wherein said array control means is located externally of said plurality of underwater vehicles.

9. An oceanographic sampling system as defined in claim 1, wherein said array control means is located in one of said underwater vehicles.

10. An oceanographic sampling system as defined in claim 1, wherein said array control means is distributed among said plurality of underwater vehicles.

11. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for controlling the shape of said array as said sensor data is acquired.

12. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for controlling the size of said array as said sensor data is acquired.

13. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for controlling the depth of one or more of said underwater vehicles as said sensor data is acquired.

14. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for controlling a direction of movement of said array as said sensor data is acquired.

15. An oceanographic sampling system as defined in claim 1, wherein said array control means includes means for controlling a velocity of movement of said array as said sensor data is acquired.

16. An oceanographic sampling system as defined in claim 1, wherein one or more of said underwater vehicles includes means for preprocessing said sensor data.

17. An oceanographic sampling system as defined in claim 1, wherein said underwater vehicles include means for distributed processing of said position data and said time-synchronized sensor data.

18. An oceanographic sampling system as defined in claim 1, wherein each of said underwater vehicles further includes a communication subsystem for transmitting and receiving position control information, navigation information and synchronization information.

19. An oceanographic sampling system as defined in claim 1, wherein said synchronizing subsystem and said navigation subsystem utilize optical communication channels between selected ones of said underwater vehicles.

20. An oceanographic sampling system as defined in claim 19, wherein said optical communication channels each include light-emitting diodes and photosensors for optical communication.

21. An oceanographic sampling system as defined in claim 19, wherein said optical communication channels each include lasers and photosensors for optical communication.

22. An oceanographic sampling system as defined in claim 1, wherein said synchronizing subsystem and said navigation subsystem utilize high frequency acoustic communication channels between selected ones of said underwater vehicles.

23. An oceanographic sampling system as defined in claim 1, wherein said synchronizing system includes an ultra stable clock for time stamping said sensor data.

24. An oceanographic sampling system as defined in claim 1, wherein each of said underwater vehicles further includes means for transferring said time-synchronized sensor data and position data to an external data storage device.

25. An oceanographic sampling system as defined in claim 1, wherein at least one of said underwater vehicles includes an acoustic excitation source.

26. An oceanographic sampling system as defined in claim 1, wherein at least one or said underwater vehicles includes an electromagnetic excitation source.

27. An oceanographic sampling system as defined in claim 1, wherein said array functions in a passive mode.

28. An oceanographic sampling system as defined in claim 1 further including an excitation source for generating an excitation signal, wherein said array functions in an active mode for sensing responses to said excitation signal.

29. An oceanographic sampling system as defined in claim 28, wherein said excitation source is located in one or more of said underwater vehicles.

30. An oceanographic sampling system as defined in claim 28, wherein said excitation source is located external to said array of underwater vehicles.

31. A method for oceanographic sampling comprising the steps of:

providing a plurality of underwater vehicles disposed in an array having an array configuration, each underwater vehicle including a propulsion system for moving said underwater vehicle independently of other ones of said underwater vehicles;

sensing an ocean parameter with each of said underwater vehicles and providing sensor data representative of the ocean parameter

determining relative position data representative of the position of each of said underwater vehicles relative to other ones of said underwater vehicles as said sensor data is acquired;

time-synchronizing the sensor data and the relative position data acquired by each of said underwater vehicles with sensor data and relative position data acquired by other ones of said underwater vehicles; and

controlling said array of said underwater vehicles as said time-synchronized sensor data and relative position data are acquired, comprising controlling operation of said array as a unit such that said underwater vehicles acquire array data sets containing information that is not present in the sensor data from individual ones of said underwater vehicles.

32. A method as defined in claim 31 wherein the step of controlling said array includes controlling said array in a preprogrammed manner.

33. A method as defined in claim 31 wherein the step of controlling said array includes providing control information to said each of said underwater vehicles as said time-synchronized sensor data and position data are acquired.

34. A method as defined in claim 31 wherein the step of controlling said array includes adaptively controlling said array in response to a condition determined during acquisition of said sensor data.

35. A method as defined in claim 31 wherein the step of controlling said array includes controlling the shape of said array as said sensor data is acquired.

36. A method as defined in claim 31 wherein the step of controlling said array includes controlling the size of said array as said sensor data is acquired.

37. A method as defined in claim 31 wherein the step of controlling said array includes controlling the depth of one or more of said underwater vehicles as said sensor data is acquired.

38. A method as defined in claim 31 wherein the step of controlling said array includes controlling a direction of movement of said array as said sensor data is acquired.

39. A method as defined in claim 31 wherein the step of controlling said array includes controlling a velocity of movement of said array as said sensor data is acquired.

40. A method as defined in claim 31 wherein the step of controlling said array includes controlling a function of one or more of said underwater vehicles as said sensor data is acquired.

41. A method as defined in claim 31 wherein the step of sensing includes passively sensing said ocean parameter.

42. A method as defined in claim 31 further including the step of transmitting excitation signals in an underwater region of said array of underwater vehicles, wherein the step of sensing includes sensing responses to said excitation signals.

43. A method as defined in claim 42 wherein the step of transmitting includes transmitting said excitation signals from one or more of said underwater vehicles.

44. A method as defined in claim 42 wherein the step of transmitting includes transmitting said excitation signals externally of said underwater vehicles.

45. A method as defined in claim 42 wherein the step of transmitting includes transmitting acoustic excitation signals.

46. A method as defined in claim 42 wherein the step of transmitting includes transmitting electromagnetic excitation signals.