Design And Implementation Of Hydroacoustic Signal Recorder With Acoustic Trigger Function

The analysis and research of hydroacoustic signals play a very important role in modern marine scientific research,and the precondition for the analysis and research of hydroacoustic signals is the acquisition and recording of hydroacoustic signals,and it is necessary to collect hydroacoustic signals in position for a long time.Domestic and foreign traditional hydroacoustic signal acquisition equipment has high power consumption,can not work for a long time under battery-powered conditions and does not have the shortcomings of acoustic trigger recording function,it is difficult to complete the long-term recording of underwater acoustic signals and selective recording.In this thesis,a low-power hydroacoustic signal recorder with acoustic trigger function is designed for recording killer whale sound signals,and the recorder has two working modes: acoustic trigger recording mode and normal recording mode.The normal recording mode can be used for long time recording.The acoustically triggered recording mode can be used for selective recording.The recorder idle standby,and the acoustic recording system of the recorder is energized to record when the killer whale sound signal is detected.The thesis describes the implementation process of the recorder in terms of overall design,hardware design,algorithm and software design.In the overall design of the recorder,the method of using the recorder,technical specifications,system composition,working principle and hydrophone selection are introduced.The sound detection system with MSP430FR5994 microcontroller as the core and the sound recording system with Raspberry Pi as the core are designed for the requirements of the two working modes of the logger.In the hardware design of the recorder,the component selection,circuit design and PCB design of the acoustic detection system were carried out for the purpose of achieving acoustic detection,working mode switching,power-on/power-off control of the acoustic recording system and replaceable frequency band sub board.At the same time,the design of the acoustic recording system was carried out in order to achieve high precision recording of hydroacoustic signals.In terms of the recorder algorithm and software design,an improved double threshold detection algorithm was designed to realize the acoustic trigger recording function,and the algorithm was implemented using C language.Finally,system testing is conducted in this thesis,and the acoustic detection system test,acoustic recording system test,acoustic recording and acoustic triggering test are conducted to verify that all functions and performance indicators of the recorder meet the expected design requirements.