Research And Application Of GPS Data Compression Algorithm

With the GPS(Global Positioning System)has been widely applied in various fields,the number of GPS terminal is increasing.A large number of GPS data need be sended form GPS terminal to the control center by real-time transmission,or be saved in GPS terminal.Under the nonincreasing hardware cost and limited bandwidth,it is very meaningfull that researching how to reduce the cost and improve the safety of the data transmission.From software level,the paper takes advantage of the data compression technique to compress the GPS data,decrease the amount of data transmission,reduce the communication cost and improve the transmisson security.Because of the compressed GPS data needs to be able to back into the original GPS data without distortion,the paper focuses on the research of lossless compression algorithm.At first,the paper analyzes the structure of different types of GPS data,puts forward the pure digital preprocessing scheme to convert GPS data into pure digital sequence which only contains digit(0-9).This scheme not only guarantees the integrity of the GPS data,but also improve the selectivity of compression algorithm.For small digital condition of GPS data preprocessed,the paper introduces Golomb-Rice coding.At the same time,the paper analyzes the existing GPS data lossless compression algorithm.According to the binary characteristic of the compressed data that compressed by the existing compression code(such as Huffman code,half byte code and so on),the paper proposes the idea of collaborative compression that using binary arithmetic code based on look-up table to compress the data compressed by other compression algorithm.The collaborative compression not only can ensure the real-time GPS data compression,but also further improve the compression ratio.Experiments show that the scheme of the half byte code collaboratived with the binary arithmetic code is the most efficiency,which guarantees the compress ratio not less than 85%.Meanwhile,both the half byte code and the binary arithmetic code based on look-up table are easy to be implemented.The scheme can ensure the real-time compression and transmission and can compress effectively GPS data,which solves the bottleneck problem of GPS data transmission.The real-time collaborative compression scheme has been applied in theconcrete transport vehicle monitoring platform project and the road transport vehicle satellite positioning system monitoring platform project in a company offering GPS services,which can guarantee the real-time collaborative compression for GPS data compression,and can greatly reduce the cost of communication.