Architecture of an acoustic multistatic system

• US 20060153006A1
• Filed: 06/03/2004
• Published: 07/13/2006
• Est. Priority Date: 06/06/2003
• Status: Abandoned Application

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: Baudoux, Jean-Pierre
• Application Number:
  US10/559,683
• Publication Number:
  US 20060153006A1
• Time in Patent Office: Days
• US Class Current: 367/124
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 15/104 wherein the transmitted pulses use a frequency- or phase-modulated carrier wave
• CPC Class Codes: G01S 15/876 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S15/872 takes precedence

Abstract

The present invention relates to a multistatic sonar system having a particular mode of communication between the emitter base and the receiver bases responsible for detecting the sonar echoes. This system makes it possible in particular to circumvent the drawbacks occasioned by the use of radio communications or of satellite-based communications generally used. The signal emitted by the emitter base comprises an apprisal pulse conveying information pertaining to the mode of operation of the system according to the invention, in particular the instant of emission, and a sonar pulse proper. This system is especially intended for use by underwater vessels while diving, for detecting and locating surrounding objects or controlling the positioning of an autonomous underwater vehicle.

Claims

1-12. -12. (canceled)

13. A multistatic acoustic system, comprising:

an emitter base comprising means of emission of sonar pulses;

a receiver base comprising means of reception and of processing of sonar echoes;

the emitter base also comprising means for transmitting mode information to the receiver base wherein the mode information is transmitted to the receiver base in acoustic form by an appraisal pulse, said appraisal pulse being modulated by a signal containing said mode information.

14. The system as claimed in claim 13, wherein an appraisal pulse and a sonar pulse are emitted by a single emitter successively emitting the two pulses.

15. The system as claimed in claim 13, wherein a sonar pulse and an appraisal pulse are separated by a time interval Δ

t dependent on the mode of operation of the system and known to the receiver bases.

16. The system as claimed in claim 13, wherein, Δ

t being equal to zero, two pulses are emitted so as to be immediately consecutive.

17. The system as claimed in claim 14, wherein, Δ

t being equal to zero, the two pulses are emitted so as to be immediately consecutive.

18. The system as claimed in claim 13, wherein a sonar pulse and an appraisal pulse are separated by a time interval Δ

t dependent on the mode of operation of the system and known to the receiver bases.

19. The system as claimed in claim 13, wherein a sonar pulse and an appraisal pulse are separated by a time interval Δ

t whose duration is transmitted to the receiver bases with the mode information.

20. The system as claimed in claim 14, wherein a sonar pulse and an appraisal pulse are separated by a time interval Δ

t whose duration is transmitted to the receiver bases with the mode information.

21. The system as claimed in claim 13, wherein the modulation of the appraisal pulse by the modulating signal containing the mode information is carried out by digital coding.

22. The system as claimed in claim 14, wherein the modulation of the appraisal pulse by the modulating signal containing the mode information is carried out by digital coding.

23. The system as claimed in claim 21, wherein the modulation of the appraisal pulse by the modulating signal containing the mode information is carried out by phase-hopping coding.

24. The system as claimed in claim 22, wherein the modulation of the appraisal pulse by the modulating signal containing the mode information is carried out by phase-hopping coding.

25. The system as claimed in claim 21, wherein the modulation of the appraisal pulse by the modulating signal containing the mode information is carried out by frequency-hopping coding.

26. The system as claimed in claim 22, wherein the modulation of the appraisal pulse by the modulating signal containing the mode information is carried out by frequency-hopping coding.

27. The system as claimed in claim 13, wherein the instant of emission of the sonar pulse is determined on the basis of the instant of reception of the appraisal pulse by the receiver bases and of the mode of operation.

28. The system as claimed in claim 14, wherein the instant of emission of the sonar pulse is determined on the basis of the instant of reception of the appraisal pulse by the receiver bases and of the mode of operation.

29. The system as claimed in claim 13, wherein the instant of emission of the sonar pulse is determined on the basis of the date of emission of said sonar pulse, contained in the mode message.

30. The system as claimed in claim 14, wherein the instant of emission of the sonar pulse is determined on the basis of the date of emission of said sonar pulse, contained in the mode message.

31. The system as claimed in claim 13, further comprising means for encrypting the mode information.

32. A process for controlling the position of an autonomous underwater craft, said process using the system as claimed in claim 17.

33. A process for controlling the position of an autonomous underwater craft, said process using the system as claimed in claim 18.

18-1. The system as claimed in claim 14, wherein a sonar pulse and an appraisal pulse are separated by a time interval Δ

t dependent on the mode of operation of the system and known to the receiver bases.