positioning key

The antenna directly affects the performance of the whole system as a key component in BD navigation positioning system.

而天线作为北斗导航定位系统中的关键部件，直接影响到整个系统的性能。

Mobile Geographic Information System Data Model and Key Technology of Geographic Information System, Global Positioning System and Remote Sensing Integration Based on Personal Digital Assistant

移动地理信息系统数据模型与3S集成关键技术

Then the key technologies applied in the system are lucubrated in the thesis, including data synchronization between Palm OS handset and PC, material positioning, bar code scan and automatic identification, etc.

随后研究了系统实现过程中采用的关键技术，包括Palm手持设备与PC机的数据同步技术、物资在途定位技术、条码扫描与自动识别技术等。

The satellite navigation system is actually a time synchronization system. The time reference of the system is the key factor that affects the accurancy of positioning and time keeping of the whole system.

卫星导航系统实际上是一个时间同步系统，系统的时间基准是影响整个系统的定位精度和授时精度的关键因素。

The key problems settled in this thesis include: geographical data organization; mobile object positioning and display.

在系统研发过程中,解决了空间数据库设计和移动目标定位这两个关键问题.