针对GPS流动站与参考站采用不同采样率的特殊应用情况，本文提出如下处理方案：当观测数据不同步时，采用历元间相位差分计算流动站高精度“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。根据同步时计算结果的差异，对不同步计算结果进行系统误差修正。新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。飞机导航实验的数据解算表明，采用这种方法，流动站的定位精度可以达到厘米级，而且位置更新率较高。

Abstract—In Global Positioning System (GPS) applications, the double-difference (DD) model is often employed, which requires that the reference station and the rover receivers adopt the same sampling rate. On the premise of the need fulfillment, could the existing static receivers of Global Navigation Satellite System networks with a low sampling rate be used as the references for the rover with a high sampling rate? If feasible, how to process such data? In this paper, an integrated processing scheme is presented to deal with such data in the posterior mode, i.e., after initialization, both the single-difference (SD) and the DD models will be employed when synchronous data are available, while only the SD model will be used when only the rover receiver data are obtained. The deviations of the results obtained with the SD model from those with the DD model at the synchronous epoch might be considered as the accumulated systematical errors, which could be linearly interpolated into individual nonsynchronous epochs of that interval. This strategy takes full advantage of all available observations, rather than discarding the nonsynchronous GPS data, and it provides a promising application for the precise kinematic point positioning. The total expense of the surveying mission will be greatly reduced by adopting the low-sampling-rate receivers of the Continuously Operating Reference Station or the other similar GPS network as the reference stations. A data set of an airplane flight experiment was processed to verify the new algorithm, and the results revealed that the positioning accuracy could reach a centimeter level.

Paper Link: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5599866