Self-propelled array system

• US 4,004,265 A
• Filed: 04/28/1976
• Issued: 01/18/1977
• Est. Priority Date: 08/02/1974
• Status: Expired due to Term

• Current Assignee: Sanders Associates, INC. (BAE Systems Plc)
• Original Assignee: Sanders Associates, INC. (BAE Systems Plc)
• Inventors: Woodruff, Thomas E., Saunders, Roger I., Ballard, Samuel S., Farmer, Everett W.
• Primary Examiner(s): Farley, Richard A.
• Application Number:
  US05/681,086
• Time in Patent Office: 265 Days
• Field of Search: 340/2, 340/3 T, 340/6 R, 9/8 R
• US Class Current: 367/4
• CPC Class Codes: G01V 1/3843 Deployment of seismic devices, e.g. of streamers equipment for marine deployment in general B63B
• CPC Class Codes: G10K 11/008 Arrays of transducers seismic streamers, see G01V1/20

Abstract

A hydrophone array system comprising a plurality of hydrophones fastened to a cable is deployed beneath the sea in a substantially horizontal straight line. A small powered thruster fastened to one end of the cable urges it in a first direction and this urging is resisted by a member, such as a drogue or an anchored subsurface float, fastened to the other end of the cable. Individual signals from each of the hydrophones are conducted to the surface where they are processed and transmitted by a radio link to a nearby aircraft or surface vessel. Beam forming and analysis is performed aboard the aircraft or surface vessel.

Claims

1. A hydrophone array system comprising a first cable, a plurality of hydrophones connected to said first cable and spaced apart by predetermined distances thereby forming an array, a buoyant body, a transmitter within said body, a second cable extending from said body, and means including said cables for conducting signals from said hydrophones to said transmitter characterized in that said system includes a thruster connected to one end of said first cable for urging it in a preferred direction and a member connected to the other end of said first cable for resisting the urging of said thruster and in that said first cable includes a section adjacent to said thruster which section comprises a first resilient portion and a second, signal carrying portion, said second portion being longer than said first portion, said portions being fastened to each other at each of their ends so that said second portion remains in a slack condition.

2. A hydrophone array system in accordance with claim 1 in which said array is constructed to be substantially neutrally buoyant and in which said thruster includes a housing of generally cylindrical shape and is constructed with a weight distribution such that when submerged said thruster is urged to a predetermined preferred attitude with its longitudinal axis horizontal so as to stretch out said array in a substantially horizontal straight line.

3. A hydrophone array system in accordance with claim 2 in which said thruster is constructed to make its center of gravity and its center of buoyancy lie in the same transverse plane but displaced from each other so that a force couple is generated which urges said thruster toward an attitude with its center of gravity below its center of buoyancy.

4. A hydrophone array system in accordance with claim 1 which includes a plurality of preamplifiers each connected to and packaged with one of said hydrophones thereby constituting a hydrophone assembly.

5. A hydrophone array system in accordance with claim 4 in which said first cable and said hydrophone assemblies are constructed so as to form an array having substantially neutral buoyancy.

6. A hydrophone array system in accordance with claim 1 in which said thruster is constructed to have negative buoyancy.

7. A hydrophone array system in accordance with claim 1 which includes an electronics package connected to said second cable adjacent to that end which is remote from said buoyant body.

8. A hydrophone array system in accordance with claim 1 in which each of said first and second cables includes both load bearing and signal carrying elements.

9. A hydrophone array system in accordance with claim 6 in which said thruster includes a housing of generally cylindrical form.

10. A hydrophone array system in accordance with claim 9 in which said thruster includes a motor within said housing and a propeller mounted exteriorly at one end thereof and operatively connected to said motor and in which said one end of said first cable is connected to the other end of said housing.

11. A hydrophone array system in accordance with claim 10 including a connection between said thruster and that end of said second cable which is remote from said buoyant body.

12. A hydrophone array system in accordance with claim 11 in which said connection includes a rigid bracket having two arms which embrace said housing and are pivotally connected thereto.

13. A hydrophone array system in accordance with claim 12 including an electronics package connected to said bracket and to said second cable.

14. A hydrophone array system in accordance with claim 13 in which said thruster is constructed to make its center of gravity and its center of buoyancy when submerged lie in the same transverse plane but displaced from each other.

15. A hydrophone array system in accordance with claim 1 in which said member is a drogue.

16. A hydrophone array system in accordance with claim 15 in which the end of said second cable remote from said buoyant body is connected to said thruster.

17. A hydrophone array system in accordance with claim 16 in which said drogue is constructed to be negatively buoyant and which includes a surface float and a third cable of the same length as said second cable extending from said float to said drogue to support said drogue.

18. A hydrophone array system in accordance with claim 1 in which said member is an auxiliary buoyant body and which includes an anchor, a third cable interconnecting said member and said anchor, and in which said first and second cables are also connected to said member.

19. A hydrophone array system in accordance with claim 1 which includes a weight and in which the end of said second cable remote from said buoyant body is connected to said other end of said first cable and to said weight.

20. A hydrophone array system in accordance with claim 19 including a second buoyant body and a third cable extending from said second buoyant body to said thruster.

21. A hydrophone array system in accordance with claim 1 which includes means for controlling the direction in which said thruster exerts said urging.

22. A hydrophone array system in accordance with claim 1 including means on said first cable for generating a first signal indicative of the orientation of said array with respect to geographic coordinates.

23. A hydrophone array system in accordance with claim 22 which includes means including a programmer for generating a second signal indicative of the desired orientation of said array and means jointly responsive to said first and second signals for controlling the direction in which said thruster exerts said urging.

24. A hydrophone array system in accordance with claim 1 including a receiver within said buoyant body for receiving command signals and means responsive to said command signals for controlling the direction in which said thruster exerts said urging.

25. A hydrophone array system in accordance with claim 1 including a housing containing said thruster and means within said housing for selectively either paying out said first cable and said array so as to extend exteriorly of said housing or retrieving said array to lie within said housing.

26. A hydrophone array assembly in accordance with claim 1 including a housing containing said thruster and in which said second cable includes a first end fastened to said buoyant body and a second end fastened to said housing and which includes means within said housing for selectively either paying out said second cable so as to extend between said buoyant body and said housing or reeling in said second cable so as to lie substantially entirely within said housing with said housing in engagement with said buoyant body.

27. A hydrophone array system in accordance with claim 1 which includes an extensible mast mounted on said buoyant body to facilitate recovery of said system.

28. A hydrophone array system in accordance with claim 1 in which said thruster includes a motor, a housing, a plurality of vibration isolators mounting said motor to said housing, a propeller mounted for rotation exteriorly of said housing, and a flexible coupling operatively connecting said motor to said housing.