地图自动综合的研究随着地图与地理信息系统科学的发展不断深入,从早期的地图目标几何量测与图形简化至制图综合知识的运用、制图综合方法评价与集成、乃至在线综合与综合服务的出现。本文针对当前移动地理信息服务对地图随时、随地为所有人和所有事提供实时服务的要求,主要探讨了移动环境中地图自动综合的概念、特征与系统架构等相关理论与技术方法。本文首先从广义的角度阐述了地图自动综合所处的移动环境,并提出其至少由计算环境、表达环境、传输环境和应用环境4个部分组成,并指出制图综合在这几个方面与传统环境的差别。进一步从制图综合基本问题出发,阐述了移动环境地图自动综合的概念。考虑用户的移动性,从制图综合发生机制、地图认知、地图信息传输等方面分析了移动环境地图自动综合的特征,主要包括制图综合范围、综合交互、综合约束、综合效率、综合表达等方面。基于OpenGIS的服务架构,扩展了移动GIS通用的Client-Server架构,设计了移动环境制图自动综合的系统架构,并分析了该系统中客户端和服务器端的功能。本文采用PostgreSQL/PostGIS作为空间数据库管理系统,在JUMP环境中,基于JTS实现了部分制图综合算法,并实现了GML和SVG的移动地图显示。最后,以南京市湖南路商业区居民地数据为例,实现了移动环境中的不同层次的居民地简化。
The study of map generalization has continuously kept up with the pace of the development of cartography and geographic information science.Map generalization has experienced the following steps: early geometric measurement of map elements,graphic simplification,map generalization knowledge applying,map generalization quality evaluation,map generalization methods integration and on-the-fly map generalization and map generalization services.Due to the requirements of mobile geographic information services that the usability of maps have to apply 4A services(Anytime,anywhere,anyone,anything),the theories and technical methods of map generalization in mobile environment should be updated.In this paper we discussed the concept,characteristics and system architecture of map generalization in mobile environment.First,in the broader sense we explained the concept of the mobile environment which the map generalization deals with in and then put forward that this environment should at least include four parts such as computing environment,visualizing environment,transmission environment and applying environment and pointed out that map generalization are different with the traditional map generalization in these aspects.Then we elaborated the concept of map generalization in mobile environment from the point of the fundamental problems in map generalization.Based on the mobility of the user,the characteristics of mobile map generalization such as the range,interaction,constraints,efficiency,visualization were analyzed from different aspects such us the happening mechanism,map cognition and map information transmission.Based on the service architecture of OpenGIS and the Client-Server architecture of mobile GIS,we designed the system architecture of map generalization in mobile environment and analyzed the functions of client and server.At last,we put forward the implementing methods of the system.We used PostgreSQL/PostGIS as the spatial database management system,implemented some map generalization algorithms based