针对GPS流动站与参考站采用不同采样率的特殊应用情况,当观测数据不同步时,采用历元间的相位差分计算流动站的高精度“伪距”,进而单独进行导航定位解算;当流动站与参考站观测数据同步时,采用双差模式。该方案不但充分利用了观测数据,而且可以节省数据采集和传输及运算的成本。飞机导航试验的数据解算表明,采用这种方法,流动站的定位精度可以达到cm级,而且位置更新率较高。
In order to process the rover and the reference stations GPS data with different sampling rates, a reasonable strategy is presented. When the observations of the rover are nonsynchronous with those of the reference station, the position of the rover will be estimated with the calculated precise "pseudo-ranges". Otherwise, the double difference (DD) model will be employed. The proposed method not only makes full use of the available data, but also saves the cost of data collection and transmission. An experiment was carried out, in which a rover receiver was mounted on an airplane while a reference station receiver was located on the ground. The rover positioning precision obtained by our presented method with nonsynchronous data was within several centimeters compared with those obtained by the DD model with synchronized observations.