Research And Design Of Remote Sensing Image Data Distribution System Based On Polling Mechanism

In recent years as the support of our country,satellite remote sensing technology in China have achieved a rap id development, an d its application is becoming more and more wide. For example, satellite remote sensing technology is wi dely applied in the GIS sy stem,natural disaster monitoring,geological surveying and mapping,urban environment,military interpretation,digital earth and other fields. The application of rem ote sensing satellite application technology depends on massive remote sensing image data which have much space-time and large storage capacity. The acquisition of sensing image data in its application is a hot topic which is researched by many researchers, Because the remote sensing image data has two characteristics: large storage capacity and timeliness.At present, the transmission of image data faces two problems. First,the large remote sensing image data storage leads to a large amount of network transmission. Second,in the distributed application environment,when the distributed network receives more and more user requests,it will increase the of server load and the throughput of server,and eventually influence the transmission efficiency.This paper analyzed the c haracteristics of the rem ote sensing image technology. Through the analysis of remote sensing image data transmission, the existing network transmission technology, the network architecture has carried on the research and analysis, polling mechanism basing on remote sensing image data transfer protocol is proposed. Under P2 P network system, remote sensing image data will be split into chunks of data. When Users download the remote sensing image data, the system will build a polling mechanism for data download module, which means the system will establish a polling cycle for the available nodes in the network. According to the transmission capacity of nodes the systerm will distribute different tasks to the nodes. If A complete assigned task but the other nodes download task haven’t completed the task, A node will continue downloading the next task ingoring whether other nodes the download complete. Pursue algorithm used in the process of data download and elimination algorithm and update algorithm for task allocation amount are used to regulate and control task allocation amount and available node topology. Through the research of the theory of the polling mechanism, this work designs a remote sensing data sharing system basing on polling mechanism.