随机模型对IGS站速度及其不确定度影响分析

Influence of stochastic model on IGS station velocity and uncertainty

针对随机模型对站速度的影响,该文以45个国际GNSS服务(IGS)核心站坐标时间序列为研究对象,提出基于Fisher信息矩阵的KIC噪声模型估计准则,对WN、PL、FN+WN、FN+RW、FN+WN+RW备选随机模型进行分析。探讨不同随机模型对IGS站速度及其不确定度估计的影响。结果表明,IGS站坐标时间序列随机模型呈现出多样性,在进行噪声模型估计及其速度应用时应选择足够代表IGS随机模型的备选噪声模型。不同随机模型对IGS站速度估计值的相对影响较小,但对速度不确定度估计值影响不可忽略,尤其是RW分量对站速度不确定度的影响更加明显。

Aiming at the impact of stochastic model on station velocity,a KIC noise model estimation criterion based on Fisher information matrix was proposed and five different noise models(WN,PL,FN+WN,FN+RW and FN+WN+RW)were considered to perform analysis on the influence of different stochastic models on the estimation of international GNSS service(IGS)station velocity and its uncertainty with 45 IGS core stations.The results showed that the IGS station time-series stochastic models were diversified,and an alternative noise model sufficient to represent the IGS stochastic model should be selected when estimating the noise and its velocity.The relative impact of different stochastic models on the IGS station velocity estimates was relative small,but their impact on the estimation of velocity uncertainty could not be ignored.In particular,the influence of RW component on station velocity uncertainty was more obvious.