基于AGPS和GSM的混合定位系统终端软件设计

针对目前汽车定位监控系统中GPS定位精度低、时间长的问题，提出了一种基于AGPS和GSM／GPRS设计的混合定位车载终端设计方案，实现了单次定位、连续定位、电量查询、电量告警等功能，大大缩短了定位时间。传统的GPS定位技术启动时间长，耗电较高，在室内很难收到卫星发回的GPS信号。本混合定位系统主要有四部分：车载定位终端、主控调度服务器、SiRF公司的定位服务器，接入服务器的多用户组成。冷启动时，本终端在用户发出定位指令后大约40S内即可迅速完成定位，首次捕获GPS信号的时间仅需几秒，连续定位可以持续上千次，大大提高了响应速度和用户体验度。

Terminal Software Design of Hybrid Positioning System Based on AGPS/GSM

View of the problems of GPS with low position presicion, long delay in current vehicle positioning and monitor system, a hybrid positioning system based on AGPS/GSM is designed to achieve functions of single location, continuous location, electricity enquiry, power alama,which greatly reduced the positioning time. Traditional GPS technology takes long time to boot up, consumes electrical energy greatly and is hard to receive GPS signal inside the room. While this hybrid positioning system is composed of four parts：terminal in the car, control server, SiRF location Server and multi-users, In cold boot, the terminal takes about 40 seconds to locate after receiving the user＇s command, several seconds to capture GPS signal, and it can do continuous location thousand times in succession which obvious improves the speed of response and the experience of uses.