Method and device for detecting underwater acoustic signal with coherent laser remote sense

Abstract

The invention discloses an underwater acoustic signal sensing method and device through coherent laser remote-sensing detector, which comprises the following steps: dividing the single-frequency laser into detecting light and reference light; transmitting the detected light to the water surface through optical heterodyne; vibrating the water surface through acoustic wave from underwater element; making the frequency and strength of underwater acoustic wave consistent with the vibrating frequency and amplitude; modulating frequency of reflective light of water surface through forced vibrating speed; interfering the reflective light and reference light detected by photoelectric detector; modulating the vibrating speed of water surface through electric heterodyne modulator; obtaining the waveshape of the underwater acoustic wave; realizing the detection of the underwater acoustic signal. The invention has high sensitivity, far distant measurement, flexible optical path and reliable structure, which is easy to modulate.

Description

technical field [0001] The invention relates to laser remote sensing, in particular to a method and device for detecting underwater acoustic signals by coherent laser remote sensing, which realizes long-distance and non-contact detection of underwater acoustic signals, and can be used as a wireless, neutral The receiving end of the long-distance communication of the relay device. Background technique [0002] Due to the different characteristic impedance of water and air, most of the underwater sound waves are reflected at the interface, and the loss of sound waves penetrating to the water surface is very large. In order to detect underwater sound signals, the receiving transducer must be immersed in water, and then detected The acoustic signal is transmitted to the underwater platform by cable or radio. This detection method with wet end relays limits the mobility of the underwater platform to detect underwater acoustic signals. [0003] In order to overcome this problem, ...

AI Technical Summary

Problems solved by technology

[0006] (1) The detection sensitivity is proportional to the cosine value cos(θ) of the laser incident angle, when the laser incident angle is small, the detection sensitivity is greatly reduced

For long-distance detection of underwater acoustic signals, it is difficult to achieve large-angle measurement, so this method cannot achieve long-distance detection

[0007] (2) The angles of transmitter and receiver must be strictly matched, and it is difficult to adjust the optical path

Images