Research On Side Scan Sonar Image Acquisition Method Based On ZYNQ

With the development and utilization of marine resources,underwater acoustic detection has become the hottest topic at present.In order to develop deep ocean and offshore resources,including petroleum resources,biological resources,etc.,it is necessary to comprehensively understand the entire marine terrain.At present,there are three important instruments for marine geomorphological surveys: side-scan sonar,multibeam sounding sonar,and three-dimensional sonar.A side-scan sonar is an active sonar that emits ultrasonic waves by itself and generates echoes after being reflected on the sea floor.Based on the time and intensity of the received echoes,it constructs the image information of the sea bottom geomorphology,and provides scientific researchers with high-resolution sea bottom images.After analyzing the side-scan sonar system in detail in this project,a side-scan sonar signal processing system and sonar image noise reduction algorithm based on ZYNQ are designed.At the same time,the side-scan sonar signal processing system designed in this paper is verified through a series of experiments.The main research contents and results of the paper are as follows:(1)Software platform construction and side-scan sonar large data transmission: A side-scan sonar embedded software system based on the Zynq processor platform was designed,and the embedded Linux system was transplanted on the ARM core,and transplanted KSZ9896 Gigabit Ethernet switch chip driver provides support for Zynqbased side-scan sonar signal processing system.For the side scan sonar data acquisition on the signal acquisition board,the large amount of data must rely on Gigabit Ethernet.The ARM core is used for system control,data handling and command interaction,and the FPGA is used for data calculation.A Linux system running Linux is proposed.The data transfer method between the ARM platform and the FPGA platform uses the ARM side to complete the task of transferring data from the ARM to the FPGA to the ARM side by using memory mapping and memory sharing methods,and achieves fast and error-free transmission of side-scan sonar data,greatly Improved overall system performance.(2)Speckle denoising method for side-scan sonar images based on adaptive BM3D: Aiming at speckle noise,a side-scan sonar image based on adaptive block-matching and 3D filtering Speckle noise reduction method is proposed.The algorithm first performs power transform and logarithmic transform on the SSS image,uses wavelet transform to estimate the overall image noise,and updates the parameters of the BM3 D algorithm with the local noise estimation results.Then the algorithm in this paper compares the results of global estimation and local estimation,and selects the most suitable parameters to solve the problem of uneven noise distribution.Experimental results show that the improved BM3 D algorithm can effectively reduce speckle noise in SSS images and obtain good visual effects.The equivalent vision of the algorithm in this paper is improved by at least 6.83%,the speckle suppression index is lower than the traditional method,and the SMPI is reduced by at least 3.30%.This method is mainly used for sonar image noise reduction,and also has certain practical value for signals contaminated by speckle noise such as ultrasound,radar or OCT images.(3)To test the whole system,firstly,a signal generator is used in the laboratory to test the effectiveness of the signal processing algorithm and the function of the whole system;then,it is designed the side-scan sonar system at the Qiandao Lake Experimental Base for the lake test The results show that the signal processing system designed in this paper can initially use the echo to detect the depth of Qiandao Lake?...