差分GPS定位精度研究

采用空间差分和时间差分两种方法, 研究了差分GPS定位精度受差分站间距离和差分改正数龄期的影响, 证明在满足差分站间距离小于100 km, 差分改正数龄期小于5 s的情况下, 各种空间相关误差以及SA对差分GPS定位精度的影响很小, 通常情况下可以忽略, 因此最终的定位误差主要取决于接收机热噪声和多路径效应.而利用一个GPS接收机的观测数据进行时间差分的方法, 无需建立差分基站, 可有效修正各种误差因素的影响, 提高定位精度.

Study on Differential GPS Accuracy

To study the relationship of accuracy of DGPS(differential global positioning system) vs. differential distances between stations, and vs. the differential pseudorange correction ages by analysis and experiment. The results show that when differential distance between stations is less than 200 km and the differential pseudorange correction age is less than 5s, the influence of various space correlated error and SA(selective availability) on DGPS accuracy is very small so that it can be ignored in ordinary situation,thus the resulting positioning errors are mainly concluded by receiver noise and multipath effect. While the time differential method introduced using the data of one GPS receiver, can effectively correct various error elements and improve the positioning accuracy without the need of setting a differential base station.