1. You didn't need a hydrophone to pick up their unmistakable sound.

2. A marine detector is a hydrophone.

3. The ultrasonic field was measured using a ultrasonic hydrophone and a 3 - D scanning system.

4. Compared with the pressure hydrophone, vector sensors have many advantages.

5. A method to obtain the vertical directivity of hydrophone triplets towed line sonar by the optimal array processing is introduced in brief at first.

6. Radial polarized tubular hydrophone was fabricated using 1- 3 piezocomposites and the free- field voltage receiving sensitivity was tested.

7. An optical fiber hydrophone TDM system employing an 1 X 4 optical switch has been constructed.

8. The neritic hydrophone is the key part of ocean seismic exploration, and its property has direct influence on the quality of seismic data acquisition.

9. Each vector hydrophone is composed of one velocity hydrophone plus another co-located pressure hydrophone.

9. is a online sentence dictionary, on which you can find good sentences for a large number of words.

10. Fiber optic hydrophone is just suit for this request. As a new age of acoustic detector, it must have high sensitivity and large dynamic range.

11. The problem how beam forming algorithm of hydrophone array is implement is studied.

12. The fiber laser can also be utilized as hydrophone to detect high - frequency ultrasound for medical applications.

13. Fiber optic hydrophone unit is the basis of fiber optic hydrophone system.

14. So the technique and application of neritic hydrophone are paid more attention by geophysicist.

15. In the time-division multiplexing fiber-optic hydrophone system, it is desired to design the signal detection circuit with large gain and bandwidth.

16. The model of vibration picking for a vector hydrophone is established.

17. According to the auditory principle of fish's stereocilium, a NEMS vector hydrophone is designed.

18. Naval Research Laboratory( NRL) of America was absorbed in the research of fiber-optic hydrophone at the beginning of 80's and placed the development of fiber hydrophone in military strategic plan.

19. The thesis also discusses the probability of intercept the attacking torpedo by utilizing the coalescent of torpedo' locate buoy and rocket depth charge, which found on the trait of vector hydrophone.

20. Furthermore, this paper presents a new method which combines sonoluminescence image, hydrophone, CHNN, B-P neural network to study ultrasonic cavitation field.

21. According to the calibration principle of electrostatic actuator and the mechanics of piezoelectric ceramic, this thesis developed auto-calibration method of hydrophone.

22. Many kinds of normal mode decomposition method have already been derived using pressure hydrophone array. But the performances of these methods are too sensitive to the signal to noise ratio.

23. According to the auditory principle of fish's stereocilium, a bionic hydrophone based on silicon is designed.

24. Time-division multiplexing (TDM) is considered as one of the most basic and effective schemes for signal transmission in the large fiber-optic hydrophone array.

25. Combining the traditional acoustic positioning system with the vector hydrophone, we have designed a new portable system named as the long base line passive acoustic positioning system.

26. This paper reports a kind of two-dimensional combined vector hydrophone of resonant-column type in which a piezoelectric accelerometer are used as are sensing element.

27. Flow noise in the interior fluid of a vector hydrophone towed linear array is analyzed.

28. There are several ways of estimating direction of arrival in use of the vector hydrophone: acoustic intensity detection, beam revolving and vector equations.

29. In this paper, beam patterns of vector-hydrophone linear array using different components of vector hydrophone were presented and compared with pressure hydrophone array.

30. The results indicated that the width of main beam of vector-hydrophone was narrower than that of pressure hydrophone array at the same aperture.

31. Then the demodulated signal and the signal of the reference piezoelectric hydrophone were input into a high-resolution digital phase detector to get the phase difference.

32. The results indicate that ESPRIT algorithm based on vector sensor can obtain higher resolution frequency estimation than that based on pressure hydrophone.

33. Optic fiber hydrophone has the highest sensitivity among current underwater sensors.

34. The hydrophone is constructed with a pressure hydrophone and particle velocity hydrophone, and is called combined hydrophone.

35. Abstract: Optic fiber hydrophone has the highest sensitivity among current underwater sensors.

36. Usually, we use three components velocity detector to measure X-component, Y-component and Z-component of velocity field. We use the hydrophone tu measure stress field.

37. This paper reports on a kind of vector hydrophone of resonant-column type in which a piezoelectric bilaminar are used as the sensing element.

38. At the meantime, the differences in performances, signal transmission and processing and other aspects between optic fiber hydrophone and traditional piezoelectric transducer have been given.

39. On the basis of lots of preliminary tests of the hydrophone, sound pressure sensitivity in the air and directivity pattern were tested as well as the ability of receiving sound signal in water.

40. Crosstalk is one of many puzzles that baffled the application to time-division multiplexing(TDM) technology for fiber-optic hydrophone array.