Cavitating Body Sonar System and Process

• US 20080002526A1
• Filed: 06/01/2007
• Published: 01/03/2008
• Est. Priority Date: 09/29/2003
• Status: Active Grant

• Current Assignee: General Dynamics Information Technology Incorporated (General Dynamics Corporation)
• Original Assignee: General Dynamics Information Technology Incorporated (General Dynamics Corporation)
• Inventors: Freeman, Larry, Lerro, Donald, Kirschner, Ivan, Uhlman, James, Martinez, Rudolph
• Granted Patent: US 7,453,769 B2
• Time in Patent Office: Days
• US Class Current: 367/87
• CPC Class Codes: G01S 15/32 using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
• CPC Class Codes: G01S 15/88 Sonar systems specially adapted for specific applications seismic or acoustic prospecting or detecting G01V1/00

Abstract

An exemplary embodiment of the present invention may include a cavitating body sonar system and method. The method may include, in an exemplary embodiment: applying a receiving-while-transmitting sonar signal processing to at least one cavitating body, over an entire range of achievable sonar operating frequencies; applying transmit wave-form shaping to a RWT sonar system employed on the cavitating body; applying heterodyne filter frequency rejection to the RWT sonar system employed on the cavitating body; applying detection processing techniques to the RWT sonar system employed on the cavitating body; employing at least one transducer as an acoustical transmitter near a scattering body comprising the cavitating body, wherein the at least one transducer is strategically located with respect to said cavitating body, at least one target, and a receiver, wherein the receiver lies in a shadow zone of the body, but the at least one target does not; and, employing at least one transducer as an acoustical transmitter near a scattering body comprising the cavitating body, wherein the at least one transducer is strategically located with respect to a cavity, at least one target, and a receiver, wherein direct propagation of a transmitted signal along the outside of the cavity to the receiver is inhibited, and reflected propagation from the acoustical transmitter to the target and thence reflected to the receiver is not inhibited.

Claims

1. A method comprising:

applying a receiving-while-transmitting (RWT) sonar signal processing to at least one cavitating body, over an entire range of achievable sonar operating frequencies;

applying transmit wave-form shaping to a RWT sonar system employed on said cavitating body;

applying heterodyne filter frequency rejection to said RWT sonar system employed on said cavitating body;

applying detection processing techniques to said RWT sonar system employed on said cavitating body;

employing at least one transducer as an acoustical transmitter near a scattering body comprising said cavitating body, wherein said at least one transducer is strategically located with respect to said cavitating body, at least one target, and a receiver, wherein said receiver lies in a shadow zone of the body, but the at least one target does not; and

,

employing at least one transducer as an acoustical transmitter near a scattering body comprising said cavitating body, wherein said at least one transducer is strategically located with respect to a cavity, at least one target, and a receiver, wherein direct propagation of a transmitted signal along the outside of the cavity to said receiver is inhibited, and reflected propagation from said acoustical transmitter to the target and thence reflected to said receiver is not inhibited.

2. The method of claim 1, further comprising:

applying a high-data-rate tracking technique to said RWT sonar system employed on said cavitating body.

3. The method of claim 1, further comprising:

employing an output of said RWT sonar system (including said transmit wave-form shaping, said heterodyne filter frequency rejection, said detection processing, and said high-data-rate tracking) to support guidance and control of said cavitating body.

4. The method of claim 1, wherein said cavitating body comprises a supercavitating torpedo.

5. The method of claim 1, further comprising:

applying transmit null steering techniques to improve performance of said RWT sonar system for said cavitating body.

6. The method of claim 5, wherein said transmit null steering technique comprises a phase cancellation technique.

7. The method of claim 1, further comprising:

applying receive beam-former spatial rejection to improve performance of said RWT sonar system for said cavitating body.

8. The method of claim 1, further comprising:

at least one fin-mounted transducer as said transmitter of said RWT sonar system for said cavitating body.

9. The method of claim 1, further comprising:

employing at least one cavitator-mounted receive array, including a receive array incorporated in a laminar flow cavitator, in combination with said at least one transmitter, said receive array serving as said receiver of said RWT sonar system for said cavitating body.

10. The method of claim 1, further comprising:

applying said RWT sonar system to said cavitating body wherein said at least one transmitter is coupled to said cavitating body at a location other than a tip of a fin.

11. The method of claim 1, further comprising:

applying said RWT sonar system to said cavitating body wherein said at least one transmitter is detached from said cavitating body.

12. The method of claim 1, further comprising:

applying said RWT sonar system to said cavitating body wherein said at least one transmitter is located on a platform from which said cavitating body is launched.

13. A method for detecting sonar signals comprising:

generating a waveform;

performing waveform shaping;

transmitting said waveform acoustically from a cavitating body;

directly receiving said acoustic waveform and reflected echoes of said acoustic waveform at said cavitating body;

performing temporal frequency rejection on said received acoustic waveforms;

optionally performing the step of spatially filtering said received acoustic waveform; and

optionally tracking said detected reflected echoes.

14. The method according to claim 13, wherein said transmitting said waveform is accomplished by emitting a single frequency continuous wave.

15. The method according to claim 13, wherein said shaping is accomplished by performing amplitude tapering.

16. The method according to claim 13, wherein said waveform shaping is performed to avoid signal discontinuities.

17. The method according to claim 13, wherein said waveform shaping is performed to avoid signal discontinuities at its beginning and end.

18. The method according to claim 13, wherein said cavitating body comprises a supercavitating torpedo.

19. The method according to claim 13, wherein said shaping comprises at least one of:

performing amplitude tapering,

avoiding signal discontinuities, and/or

avoiding signal discontinuities at its beginning and end.

20. The method according to claim 13, wherein said cavitating body comprises at least one of:

an increased aperture homing cavitator,

a torpedo,

a supercavitating body,

a supercavitating torpedo, and/or

a plurality of cavitating bodies.