Research On Key Technologies Of Post-earthquake On-site Information Collection And Fast Image Acquisition Based On Mobile GIS

Recently, earthquake disasters occur frequently in China, it brings enormous destruction which causes serious casualties and huge economic losses. Post-earthquake information collection and disaster analysis is important for the post-earthquake on-site emergency work, but problems like low effectiveness of post-earthquake information collection and difficulties on fast acquisition of post-earthquake images for analysis still exist, due to limitations of technical means and existing standards. These existed problems reduce the efficiency of post-earthquake on-site emergency work.In order to solve the existing problems in the current post-earthquake on-site information collection and image acquisition and enhance the efficiency of post-earthquake on-site emergency work, a further study is conducted in this paper based on analyzing the existing problems using mobile GIS technology, Five-layer Fifteen-level tile organization technology, etc. The main contents of this paper are summarized as follows:1) Analyzing the causes of low effectiveness of post-earthquake information collection in China, by conducting classification, grading and spatial extension on national earthquake sharing data, and connecting embedded system with external high-precision GPS devices to achieve high effectiveness of post-earthquake information collection, which also provides the superior earthquake emergency command system with high efficient data support.2) A five-layer fifteen-level tile organization technology is introduced, and a unified storage and management is adopted on processing multi-source and heterogeneous images of the quake hitting area. Using the tile map service, multi-temporal tiles with high spatial and temporal resolution can be provided for post-earthquake on-site staff and the difficulties for on-site staff to obtain the post-earthquake images for analysis can be solved.3) A tile cache replacement strategy for Five-layer Fifteen-level named UPBA (User Preference Based Tile Cache Replacement Algorithm) is proposed and the loading of Five-layer Fifteen-level tile data is optimized to achieve fast displaying of Five-layer Fifteen-level tiles in the embedded system which is limited in memory capacity.After all the studies, a set of earthquake emergency working system is designed and developed using GIS service, Android embedded system development technology and SSH (Struts + Spring + Hibernate) layered architecture. Aiming at the existing problems of post-earthquake information collection and fast image acquisition in the present post-earthquake on-site emergency work, by integrating previous studies in this paper, the system provides a complete solution to effectively enhance the efficiency of the post-earthquake on-site emergency work, which meets the actual needs of post-earthquake on-site emergency work.