Tile Map Service

Abstract: This paper introduced a way to implement 3D WebGIS system which was based on WebGL technology. The system used Ellipsoidal Mercator projection and WGS84 coordinates, made JSON file format for network transformation, described popular method for tile map service, and finished a prototype system of 3D WebGIS. The prototype system was applied in a Remote Sensing Catalogue Service system. At last the paper discussed what's the good and bad aspects of WebGL.

Abstract: Within a digital map service environment, the rapid growth of Spatial Big-Data is driving new requirements for effective mechanisms for massive online vector map tile processing. The emergence of Not Only SQL (NoSQL) databases has resulted in a new data storage and management model for scalable spatial data deployments and fast tracking. They better suit the scenario of high-volume, low-latency network map services than traditional standalone high-performance computer (HPC) or relational databases. In this paper, we propose a flexible storage framework that provides feasible methods for tiled map data parallel clipping and retrieval operations within a distributed NoSQL database environment. We illustrate the parallel vector tile generation and querying algorithms with the MapReduce programming model. Three different processing approaches, including local caching, distributed file storage, and the NoSQL-based method, are compared by analyzing the concurrent load and calculation time. An online geological vector tile map service prototype was developed to embed our processing framework in the China Geological Survey Information Grid. Experimental results show that our NoSQL-based parallel tile management framework can support applications that process huge volumes of vector tile data and improve performance of the tiled map service.

Abstract: The invention provides a mass small tile file storage management method based on hadoop. According to the method, sequencing is carried out through a Hibert curve, and then, grid tile data is subjected to serialization compression storage by a Sequence File technology of the hadoop pre se; when tile compression blocks are generated, the multithreading parallel compression of a plurality of servers is realized, tile index information is generated, and the mass file library entering storage speed is accelerated; the regular naming of block file names is managed, and efficient storage, fast reading and high-performance grid data service can be provided for mass multi-source and multi-version grid small tiles; and ITMS (Improved Tile Map Service) is designed, and the problem of delay and bandwidth occupation caused by original data transmission and real-time data processing request responding, so that the project data retrieval and transmission requirements are met.

Abstract: In order to upgrade the WebGIS legacy systems smoothly, and improve the response speed of traditional WebGIS and user experience, this paper designs and develops a tile map service based on middleware technology. Through systematic analysis of its basic principle and system architecture, this paper gives several optimization strategies. Finally, we make a performance comparison between tile map service middleware and traditional OGC (Open Geospatial Consortium, OGC) standard WMS service. Our experimental results show that the average response time of tile map service reduced by 46% than sending WMS request to WMS server directly, and the TMS middleware has a high efficiency when cutting map tiles dynamically because of its meta-tiling strategy. The study shows that tile map service middleware has important application value both in improving traditional WebGIS performance and in upgrading existing legacy systems.