Design And Implementation Of High-precision Calibration System For Submarine Survey Array

At present,as an important marine technology,the submarine hydrophone array is widely used in monitoring the marine environment and marine organisms,as well as in underwater sonar monitoring and anti-submarine warfare in the military field.The direct factor affecting the positioning and exploration accuracy of the seabed hydrophone array is the accuracy of the position information of each array element in the array,so the array position calibration has a strong practical significance.This paper takes the seabed measurement array calibration as the application background,carries out a series of design and development on the hardware circuit and software program of the calibration system,and carries out theoretical analysis on the corresponding positioning model and algorithm,And conduct laboratory and lake experiments to verify the calibration system of the designed and implemented seabed measurement array.Firstly,This paper analyzes the application scenarios and hydroacoustic positioning principles of the submarine survey array calibration system,and summarizes the overall design requirements of the system.,and derives the overall design requirements of the system based on its working principles.The entire calibration system is divided into transmitting units,receiving units,and computing units.Based on the lack of experimental conditions for the seabed measurement array in the early stage and the monitoring requirements for the working status of the submarine buoy in the later stage,a collection unit is designed to participate in debugging,and then the functional requirements of each unit are analyzed,And corresponding design indicators,and finally select the key components in the developed plan.The hardware platform design of the calibration system is divided into a transmission unit and a collection unit.Based on the requirements of hardware architecture for functional implementation,the above two subunits adopt an ARM+FPGA design scheme,and the ZYNQ7020 processor is selected as the logic control and data processing core.Detailed design was carried out on the power supply module,core board SOM-TLZ7020 module,and peripheral module of the transmission unit.The collection unit adopts an integrated core board AC7020 with external circuit boards due to the limited volume inside the cabin,and introduces the integrated resources and circuit design of the core board.Based on the hardware design of the transmitting unit and the acquisition unit,an embedded operating system was built and the application program was developed.The display and control interface of the transmitter unit,the Linux operating system construction,and the ARM and FPGA programs are designed in detail.The transmission of the calibration signal in synchronous mode is realized.The ARM and FPGA of the acquisition unit are functionally designed to realize the acquisition,storage,preprocessing and data upload of calibration signals.The positioning principle of TOA(Time of Arrival)algorithm and TSOA(Time Summation of Arrival)algorithm is analyzed theoretically,and formula derivation and model simulation are carried out.Finally,functional and performance tests were conducted on the calibration system.Test the power module,interface module,and GNSS positioning accuracy in the hardware system.Separate tests were conducted on the synchronous clock signal generation,custom signal generation,and signal transmission of the transmission unit,and the results met the design specifications.In the lake test stage,the acquisition unit cooperated with the calibration signal to complete its own calibration,and the system was tested as a whole to verify the expected design function of the calibration system.