Design Of Map Service System And Research Of Path Search Algorithm

With the increasingly blend and coordinated development of science and technology in modern society,the wide application of map service technology deeply affects all areas exposed to us every day. The smallscope includes people’s location search, traffic travel and road navigation so on, and the big scope includesthe state’s logistics transportation, emergency rescue and military action so on. As a part of the subject ofGeographical Information System (GIS), with the rapid development and progress of computer technology,artificial intelligence technology and graphics technology so on, the map service technology is increasinglydeveloped and perfected.The main function of map service is to store, publish, organize and manage vast massive of spatialdata to facilitate client’s functions including online search, retrieval, analysis and download, whichefficiently uses the information of real-time network map, and meet the different realities requirements. Asan important part in the map service, because of the constantly development of graph theory and datastructures, path search function gradually became a very important application in map service. Themutually combination of different kinds of traditional classic path search algorithm makes various of newand realistic shortest path search algorithm being researched out constantly, especially the reliability ofalgorithm steps, the time and space complexity of algorithm operation and the application range of thealgorithm result.On the whole, there are three search strategies about map service system including breadth-first searchstrategy, depth-first search strategy and heuristic search strategy in the traffic network. Several maturestudies of classical path search algorithms focus on Dijkstra algorithm and A*algorithm. Among them, theDijkstra algorithm is a greedy algorithm, and the basic principle is to choose a local optimal solution inorder to get a final overall optimal solution in every calculation step. However, the A*algorithm is aheuristic search algorithm to find the most promising node as the search target by trying the greatestpossible to load and calculate the known information, which has a very good effect on the aspect of findingthe shortest path problem in a static traffic network.A deep analysis and research on several typical path search algorithm were done by this paper, and on the base of hierarchical road network, taking the situation that a large number of variables intoconsideration in the real-time map service. What’s more, this paper puts these different values of the impactfactors such as road property and traffic information loaded into the path search calculation formula to get apath priority level by algorithm calculation, which makes the logic of path calculation more clearly. Withthe recombination of project background and the different restricted conditions, especially the user needs inroad network, we can calculate the “spatial distance” shortest selected path,“time distance” shortestselected path and “economic distance” shortest selected path so on. Finally the specific experimental dataanalyses verify the stability, superiority and efficiency of this path computation in the map service.