长距离稀疏参考站下网络RTK电离层误差内插模型精度分析

Interpolation Accuracy Analysis of Ionospheric Error for Long-Range and Sparse Reference Stations of Network RTK

针对现有内插模型是否能够满足长距离稀疏参考站下电离层误差内插精度要求的问题,以线性内插模型、距离相关内插模型作为研究对象,首先结合误差传播定律从理论上比较两种内插模型对参考站间电离层延迟估值误差的抗差性;然后选取多组距主参考站不同距离的实例数据,分析比较模型内插精度的变化规律。实例结果表明:LIM模型内插精度分布较均匀,且优于DIM模型;对比中长距离(<100 km),在长距离稀疏参考站下,模型内插精度明显降低,特别是对于电离层误差波动范围较大的卫星,其内插偏差超过±3 cm的达到50%以上。

According to the problem that under long-range and sparse reference stations condition the interpolation accuracy of ionospheric error with exiting interpolation model whether to meet the practical requirements, in this paper the linear interpolation model and distance linear interpolation model were studied. Firstly, based on the law of errors propagation, the model＇s robustness to ionospheric error between reference stations was compared. And then multiple sets of instance data with different distance from the main reference station were selected in order to analyzing the change regularity of interpolation accuracy. The results showed that interpolation accuracy with LIM model was better than DIM model and had well-distributed. Compared with result that distance between reference stations was less than 100 km, interpolation accuracy decreases obviously under long-range and sparse reference stations condition, especially for the satellite whose ionospheric error was large range, the interpolation error beyond ±3 cm was more than 50%.