中文说明：单点定位也叫绝对定位是利用伪噪声码进行定位的主要形式,具有高效率、低成本等优点。理论上,只需要三颗卫星的观测值就可以求得测站三维坐标。考虑到接收机钟差影响,在定位时必须将接收机钟差当作一个未知参数与位置参数一起求解。因此,一般需要利用四颗以上卫星的伪距观测值才能进行定位。传统单点定位是指利用单台接收机的测码伪距及广播星历的卫星轨道参数和卫星钟差改正进行定位。由于测码伪距的精度一般为米级,广播星历的轨道精度为米级,卫星钟差改正精度为士纳秒左右,因此,关闭后,单点定位置信水平的平面精度是米级,高程精度是十米级。
English Description：
Single point positioning, also known as absolute positioning, is the main form of positioning using pseudo noise code, which has the advantages of high efficiency and low cost. In theory, only three satellite observations are needed to obtain the three-dimensional coordinates of the station. Considering the influence of the receiver clock error, the receiver clock error must be considered as an unknown parameter and solved together with the position parameter. Therefore, it is generally necessary to use the pseudo range observations of more than four satellites for positioning. Traditional single point positioning refers to positioning by using the code pseudo range of a single receiver, the orbit parameters of broadcast ephemeris and the correction of satellite clock error. Because the precision of code pseudo range is generally meter level, the orbit precision of broadcast ephemeris is meter level, and the clock error correction precision of satellite is about SNS, the plane precision of single point positioning confidence level is meter level and the elevation precision is 10m level after closing.