maintenance subsystem meaning in English

维护子系统
维系子系统

The system stores spatial data and characteristic data into central database , and provides services to users in server / client mode . as the research emphases of this thesis , several key sub - systems are designed and realized . the digital map input and maintenance subsystem performs format conversion , editing and updating of spatial data ; the rail - track video playing subsystem uses video recording as reference data , then plays , inquires and traces the corresponding frames in synchronous to the scaled mileage , realizing the query of the active picture frames ; the digital map query subsystem fulfills the map query , preview and spelling of digital map orthograph
其中，地形图输入与维护实现了数字地图的格式转换、编辑处理以及空间数据的更新操作，解决了不同格式空间数据的互相转换问题；线路录象播放将线路录像数据作为系统的一种索引数据，活动影像的画面与里程相对应，实现了基于线路录像的播放、查询和检索的功能，实现了基于活动画面的查询检索功能；数字地图子系统完成了图形查询、数字地图与线路正射图像浏览、图幅拼接等功能。