The Research Of Remote Sensing Spatial Data Sharing Scheme Based On P2P Network

With the innovation of satellite remote sensing technology in our country, the amount of remote sensing spatial data and the data demand of users is increasing exponentially. So sharing massive remote sensing spatial data efficiently will push the development of the remote sensing research and application in various industry.RADI(Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences) built a remote sensing spatial data sharing system, but the existing system has a problem that data sharing efficiency is low. On the basic of the existing system, this paper proposed a remote sensing spatial data sharing scheme based on peer-to-peer network, and this scheme is applied to the real project for testing and improving.The research of this paper focus on two parts:the update and discovery of the resource, downloading data from multi-node at the same time.Firstly, a resource management and retrieval model is proposed. The resource index directory is synchronized between central directory server and super-nodes, this makes the central directory server and each super-node can provide complete query service, so the timeliness of resource and robustness of the network are enhanced. The retrieval efficiency is improved by retrieving resource in the order of "local-center-other parts".Secondly, we proposed a multi-node parallel data transmission model. The transmission of the entire data will be realized by getting data blocks from multi-node in parallel, and further this model optimizes the allocation of the data block transmission tasks from the perspective of the total comptetin time. Thereby this model realizes the function of downloading data from multiple nodes, at the same time, the model not only improves the data transmission efficiency, but also achieves the load balancing between resource nodes.Finally, this spatial data sharing scheme is applied to the real project for testing. The experimental result showed that this scheme can improve the sharing efficiency of remote sensing spatial data, and it verifies the viability and the advantages of the research achievement.