摘要
提出一种顾及参数稀疏的GNSS瞬时钟差模型构建算法,该算法通过在最小二乘多项式拟合中附加L 1范数项(Lasso)进行约束,并采用滑动建模的方式拟合钟差模型,即滑动Lasso拟合法。使用GFZ 300 s钟差产品作为训练数据,通过10折交叉验证获得正则化参数,建立钟差模型,并与常用的钟差建模加密算法进行卫星钟差拟合精度与PPP定位精度对比。实验结果表明,滑动Lasso拟合法在进行钟差拟合建模时,对于局部钟差数据中出现跳变过大的钟差值,可以有效消除其在拟合过程中对模型造成的影响,防止模型过拟合,进而提高钟差模型的拟合精度与PPP定位精度。
We propose a GNSS instantaneous clock offset model construction algorithm considering parameter sparsity.The algorithm is constrained by adding L 1 norm term(Lasso)to the least squares polynomial fitting,and the clock offset model is fitted by sliding modeling,that is,sliding Lasso fitting method.Using GFZ 300 s clock offset products as training data,the regularization parameters are obtained through 10-fold cross-validation,and the clock offset model is established.The satellite clock offset fitting accuracy and PPP accuracy are compared with the commonly used clock offset densification algorithm.The experimental results show that the sliding Lasso fitting method can effectively eliminate the influence of excessive jump of clock offset in local clock offset data during the fitting process,prevent the model from overfitting,and improve the fitting accuracy and PPP accuracy of the clock offset model.
作者
周圣淇
王中元
胡超
王瑞光
姚雪燕
ZHOU Shengqi;WANG Zhongyuan;HU Chao;WANG Ruiguang;YAO Xueyan(School of Environment and Spatial Informatics,China University of Mining and Technology,1 Daxue Road,Xuzhou 221116,China;School of Spatial Information and Geomatics Engineering,Anhui University of Science and Technology,168 Taifeng Street,Huainan 232001,China)
出处
《大地测量与地球动力学》
CSCD
北大核心
2024年第3期263-266,320,共5页
Journal of Geodesy and Geodynamics
基金
江苏省自然科学基金(BK20181361)。
