一种嵌入式导航终端的兴趣点数据处理方法

A METHOD FOR POI DATA PROCESSING BASED ON EMBEDDED NAVIGATION TERMINAL

嵌入式导航电子地图是一种精简的特殊电子地图,在现代车载导航系统中具有重要应用。实际的应用要求导航系统对卫星信号作出快速反应并对其数据进行实时更新,但由于设备存储资源的相对不足和软硬件功能的限制,其实际的数据存储具有显著的容量存储和读出限制。为了提高导航电子地图设备对数据的存储和快速查询性能,提出一种处理兴趣点数据POI(Point of Interest)的方法。该方法在提取导航电子地图数据所需要的POI数据时建立网格空间索引,对POI的数据按照网格进行存储;根据POI数据的特点,对字符数据寻找公共前缀子串,将其存储为公共前缀子串表,POI字符数据中如果存在公共前缀子串,则记录其在公共前缀子串表中的位置。以北京部分地图为例对该方法做调试,使用该方法 POI地图原始数据大小由原来的170 MB减小到35MB,空间查询200个POI花费的平均时间由3秒缩短至150 ms。该方法具有较高的压缩率和空间查询效率,对于导航电子地图中的POI数据处理具有较强的适应性。

Embedded navigation electronic map is a special streamlined electronic map and has important application in modem vehicular navigation system. In application practice the navigation system is required to respond quickly to satellite signals and to timely update its data, but due to the relative lack of equipment storage resources and the limitations in hardware and software functions, its actual data storage has significant restraints on storage capacity and reading out speed. In order to improve the performance of navigation electronic map equipment in data storage and quick query, we propose a method for processing the point of interest （PO1）. It establishes grid spatial index when extracting the POI data required by navigation electronic map data, and stores the POI data in accordance with the grid; According to the characteristics of POI data, it finds common prefix substring for character data and stores them as a common prefix substring table ; If there is the common prefix substring in POI＇ s character data, then its location in common prefix substring table will be recorded. Taking the map of Beijing city as an example to test this method, it is found that with this method the original data size of POI map is reduced to 35 MB from 170 MB, and the average time of querying 200 POI data is reduced to 150 ms from 3 seconds. The method has higher data compression ratio, better spatial querying efficiency, and strong adaptability for processing the POI data in navigation electronic map.