一种估计接收机伪距硬件延迟的多频非组合PPP模型

A multi-frequency uncombined precise point positioning model with receiver pseudorange hardware delay parameters

在传统多频非组合精密单点定位(PPP)模型中,由于伪距和相位观测方程包含相同的接收机钟差参数,使得电离层延迟、模糊度参数吸收了部分接收机端伪距硬件延迟(PHD)。为此提出一种直接估计接收机端PHD的多频非组合PPP模型,实现了电离层延迟、模糊度参数与接收机PHD的有效分离,使得模糊度参数不受接收机端PHD的影响,从而获得更优的定位性能。利用MGEX跟踪网全球275个测站的多频实测数据,分别采用传统多频非组合模型(UC-PPP)、估计接收机差分码偏差(DCB)的多频非组合模型(UC-PPP-rDCB)以及所提出的模型进行PPP实验。结果表明,所提出模型在定位精度上优于UC-PPP模型和UC-PPP-rDCB模型,其中在E方向上较其他两种模型的提升幅度分别达到33.3%和14.3%,在3D方向上较其他两种模型可分别提高8.55%和2.20%;在收敛性能上与UC-PPP-rDCB模型相当,其间的差异在1 min内,均优于UC-PPP模型。

Due to the pseudorange and phase observation equations contain the same receiver clock error parameters in the traditional multi-frequency uncombined precise point positioning(UC-PPP)model,the pseudorange hardware delay(PHD)at the receiver-side is absorbed by ionospheric delay and ambiguity parameters.Therefore,a multi-frequency uncombined PPP model is proposed in which the PHD parameter at the receiver-side for each frequency is estimated directly,and thus the receiver PHD can be separated from ionospheric delay and ambiguity parameters effectively,so that the ambiguity parameters are not affected by receiver PHD,and the better positioning performance can be obtained.Multi-frequency observations of 275 stations in the MGEX tracking network are used to design PPP experiments.The traditional multi-frequency uncombined PPP model,the multi-frequency uncombined PPP model(UC-PPP-rDCB)with receiver differential code bias(DCB)parameters and the proposed model are used for the experiments.The results show that the proposed model is superior to the UC-PPP model and the UC-PPP-rDCB model in terms of positioning accuracy.Compared with the other two PPP models,the accuracy improvement ranges at the E direction are 33.3%and 14.3%respectively,and 8.55%and 2.20%at the 3D direction respectively.The convergence performance of the proposed model is comparable to the UC-PPP-rDCB model with difference is within 1 minute,which are both better than that of the UC-PPP model.