Reasonable stochastic model and function model are the premise of accurate velocity determination, especially in the time-differenced carrier-phase (TDCP) method. This paper presents, first, an elevation-dependent stochastic model (ESM), and then gives a simplified and unified Galileo/GPS combined TDCP function model, where the inter-system bias (ISB) variations are analysed based on correlation coefficients and the scaled sensitivity matrix. To evaluate the performance of the proposed models, datasets collected at 10 multi-GNSS experiment (MGEX) stations and a vehicle kinematic experiment are employed. The results indicate that the ESM model can improve the accuracy of the velocity solution, especially for the Galileo/GPS combined system, in comparison with the equivalent weight ratio method. In contrast to the Galileo-only velocity solution, the Galileo/GPS combined velocity solution can bring improvements of about 1–1⋅5 mm/s, 0⋅5 mm/s and 1⋅5–2⋅5 mm/s in East, North and Up components, respectively. Compared with the traditional Galileo/GPS TDCP model, the simplified and unified model shows no obvious differences in all components in the environment with more visible satellites, but it performs better in a challenging environment with few visible satellites.

中文翻译：

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使用独立接收器对伽利略和伽利略/GPS 速度确定进行建模和评估

合理的随机模型和函数模型是准确确定速度的前提，特别是在时差载波相位（TDCP）方法中。本文首先提出了一个高程相关随机模型（ESM），然后给出了一个简化和统一的伽利略/GPS组合TDCP函数模型，其中基于相关系数和缩放比例分析了系统间偏差（ISB）的变化。灵敏度矩阵。为了评估所提出模型的性能，使用了在 10 个多 GNSS 实验 (MGEX) 站收集的数据集和车辆运动学实验。结果表明，与等效权重比法相比，ESM模型可以提高速度求解的精度，特别是对于Galileo/GPS组合系统。与仅伽利略的速度解相比，Galileo/GPS 组合速度解决方案可以分别在东、北和上分量带来约 1-1×5 mm/s、0×5 mm/s 和 1×5-2×5 mm/s 的改进。与传统的Galileo/GPS TDCP模型相比，简化统一模型在可见卫星较多的环境中各组成部分无明显差异，但在可见卫星较少的挑战性环境中表现较好。