Research And Implementation Of Ocean Multi-channel Seismic Cable Data Compression Method Based On Adaptive Huffman

Seismic exploration technology is the main means of ocean engineering exploration.With the improvement of the development of seismic exploration equipment,the resolution of its acquisition equipment is high and The amount of seismic data in the transmission process of seismic exploration increases,which makes the transmission bandwidth insufficient and transmission efficiency low.And it can not guarantee the real-time transmission of seismic data.The data compression technology carried in seismic exploration transmission system can not only alleviate the problem of large amount of data in transmission,but also speed up the transmission efficiency and which provides a good solution for real-time transmission of marine exploration equipment transmission system.Real-time data compression technology in marine exploration equipment is not common in practical application.Therefore,it has great development value and application prospect to add real-time data compression technology into the trans-mission system of Marine exploration equipment.The adaptive Huffman data compression algorithm adopted in this paper is a method to solve the practical problems of limited storage capacity and insufficient transmission bandwidth of marine multi-channel seismic data transmission system.According to the characteristics of ocean multi-channel seismic data haul,this design analyzes the structural characteristics of ocean multi-channel seismic data haul,such as type,range distribution,probability distribution,etc.This paper studies the real-time compression method and implementation scheme based on Marine seismic streamer data transmission system from two aspects of software algorithm testing and data compression algorithm hardware transplantation.In terms of software testing,the actual seismic detection data were used as the data source,and the performance of the adaptive Huffman compression algorithm for Marine multi-channel seismic drag data compression was tested by using the Matlab software and C++ software programming:the "bitwise" reading compression rati-o of the sampling points was increased by 1.5times,and the compression time was shortened by 1 times.According to the experimental results,after comparing the data through repeated tests with control variables,it can be seen that the design has a better compression effect for the high frequency signal data with low amplitude and integer sampling points in the cycle,and achieves remarkable optimization in both compression time and compression ratio.On the basis of algorithm research,the adaptive Huffman hardware compression and decompression porting method based on FPGA(Field Programmable Gate Array)hardware platform is studied and uses the real seismic data collected by actual Marine exploration equipment.It provides a signal source for the hardware implementation of data compression for ocean multi-channel seismic data haul,and realizes the hardware of data compression algorithm.RAM is used to construct Huffman tree,and RAM is used to solve the problem of tree updating and moving.Using register address and value corresponding method,Huffman tree node fast search traversal,greatly save the compression time,improve the compression performance;The seismic data are stored in FIFO ”by bit” and read separately by FIFO,which not only saves resources but also has better compression effect.According to the analysis of the experimental results,it can be concluded that the design has a great advantage in the compression performance of multi-channel seismic towing data,which can reduce the bandwidth pressure of the traditional Marine multi-channel towing cable transmission system and transmit data more efficiently in real time.