一种差分码偏差估计的简化模型及其评估分析

提出一种差分码偏差估计的简化模型，将测站方向上各穿刺点的VTEC简化为一个参数，分时段进行直接估计。为验证该方法的有效性，采用球谐函数建模和基于GIM的估计方法进行比较分析。选用2016-01近200个IGS测站的GPS+GLONASS数据进行实验，并采用CODE提供的产品进行验证。结果表明，对于GPS(GLONASS)卫星DCB，该方法与其他2种方法估计的结果比较接近，与CODE产品相比平均偏差和标准差分别为-0.3～0.5 ns(GPS)、1.3～0.7 ns(GLONASS)和0.05~0.20 ns(GPS)、0.14~1.10 ns(GLONASS)；对于接收机DCB，3种方法与CODE产品的平均偏差分别为-0.6～0.7 ns(GPS)和-1.5～1.5 ns(GLONASS)。实验结果验证了差分码偏差估计简化模型的有效性。

A Simplified Model for DCB Estimation and Its Assessment Analysis

We propose a simplified model for differential code bias estimation, which simplifies the VTEC of each puncture point in the direction of the station into a parametric sub-period for direct estimation. To verify the validity of the method, a comparative analysis is performed using the spherical harmonic function modeling and the GIM estimation-based method. GPS+GLONASS data from nearly 200 IGS stations in January 2016 were selected for the experiments and validated with the products provided by CODE. The results show that for GPS(GLONASS) satellite DCB, the method is relatively close to the results estimated by the other two methods, and the mean deviation and standard deviation compared with the products of CODE are -0.3-0.5 ns (GPS)、-1.3-0.7 ns(GLONASS) and 0.05-0.20 ns (GPS)、0.14-1.10 ns(GLONASS), respectively. For receiver DCB, the mean deviation of the three methods compared with the products of CODE are -0.6-0.7 ns (GPS) and -1.5-1.5 ns (GLONASS), respectively. The experimental results verified the validity of the simplified model of DCB.