gps 工作原理简介.ppt

李志
学号:PZ102024114
GPS的基本工作原理
The working principle of GPS
GPS的基本工作原理· · ··  GPS的工作原理,简单地说来,是利用我们熟知的几何与物理上一些基本原理。首先我们假定卫星的位置为已知,而我们又能准确测定我们所在地点A至卫星之间的距离,那么A点一定是位于以卫星为中心、所测得距离为半径的圆球上。进一步,我们又测得点A至另一卫星的距离,则A点一定处在前后两个圆球相交的圆环上。我们还可测得与第三个卫星的距离,就可以确定A点只能是在三个圆球相交的两个点上。根据一些地理知识,可以很容易排除其中一个不合理的位置。当然也可以再测量A点至另一个卫星的距离,也能精确进行定位。以上所说,要实现精确定位,要解决两个问题: 其一是要确知卫星的准确位置; 其二是要准确测定卫星至地球上我们所在地点的距离。下面我们看看怎样来做到这点。GPS导航示意图
GPS概况
怎样确知卫星的准确位置
时间基准问题
图片示例
How to know precisely satellite precise position
Want to know precisely where satellite precise position. First of all, the thoughtful, optimize the design of satellite orbit, and, by monitoring station through various means, continuous monitoring satellite operation state, timely send control instruction, make the satellite keep in the right orbit. Will the right running track creation ephemeris, injection satellite, and via satellite sent to the GPS receiver. Correct receiving each satellite ephemeris, can know precisely satellite precise position.
怎样确知卫星的准确位置 要确知卫星所处的准确位置。首先,要通过深思熟虑,优化设计卫星运行轨道,而且,要由监测站通过各种手段,连续不断监测卫星的运行状态,适时发送控制指令,使卫星保持在正确的运行轨道。将正确的运行轨迹编成星历,注入卫星,且经由卫星发送给GPS接收机。正确接收每个卫星的星历,就可确知卫星的准确位置。
Time benchmark problem
GPS system in each satellite on device has a very sophisticated atomic clock, and the monitoring station regular calibration. Satellite sends navigation information, and at the same time also send accurate timing information. GPS receiver receive this information, and its own clock synchronization, can obtain the correct time. So, GPS receiver in addition to accurate positioning, but also can produce accurate timing information.