Pocket PC-based Full Feature Data Collection System for 1∶50000 GIS Database Updating

With the rapid development of the economy in China,constant changes have taken place in demanding for up-to-date fundamental geographical information,which require for updating and complementing the fundamental geographical information database.In order to meet the requirement for national 1∶50 000 fundamental geographical information database updating,this paper focuses on the technical scheme of the field GIS data collection system based on embedded Pocket PC.Key points are discussed which are full feature terrain object's attributes code management,spatial data collection,data collection design principle of GIS data collection software.One type of data structure based on nesting link table,from which the two-time-object-abstracting is infered,is given in details.A smoothing method with multiGPS-point is proposed.In addition,analyses of field data recording and embedded multi-thread software designing are shown.