论文标题
通过相对论精确的点定位时间比较来确定地势差异：使用模拟观测值的案例研究
Determining geopotential difference via relativistic precise point positioning time comparison: A case study using simulated observations
论文作者
论文摘要
根据一般相对论理论（GRT），可以通过使用精确点定位（PPP）时间传输技术比较精确时钟之间的时间差异来确定地球差异（GD），称为相对论PPP时间比较方法。我们专注于两个精确时钟之间的高精度时间比较，用于使用相对论PPP时间传输确定GD，并进行了模拟实验以验证方法。在实验中，我们考虑三种情况来使用具有不同稳定性的时钟评估方法的性能，即，在三个选定地面站配备的时钟的频率稳定性分别为（案例1），（情况2），（情况2）和（情况3）。结论是从实验结果中得出的。首先，高精度时钟可以显着提高PPP时间传输的准确性，但是改进受测量噪声的限制。与案例1相比，在情况2和3中，OPMT-BRUX和PTBB-BRUX的长期稳定性得到了改善。案例1-3的频率稳定性约为4.28*10-16、4.00*10-17，3.22*10-17，在10天平均opmt-brux和10天平均PTBB-BRUX，这些价值为10-13 8.17*10-17和4.64*10-17。其次，任何两个站点之间的地势差异都可以在分解表级别确定，其精度与情况1-3中时间链接的稳定性一致。在情况3中，确定的OPMT和BRUX之间确定的地势差异偏离了特征6C4模型值，而不确定性为1.11 m2/s2，而ptbb和brux之间的偏差为0.76 m2/s2，未确定的偏差为1.79 m2/s2，未确定的偏差为1.79 m2/s2。本研究中提出的方法也可以应用于测试GRT。
According to general relativity theory (GRT), the geopotential difference (GD) can be determined by comparing the change in time difference between precise clocks using the precise point positioning (PPP) time transfer technique, referred to as the relativistic PPP time comparison approach. We focused on high-precision time comparison between two precise clocks for determining the GD using the relativistic PPP time transfer,and conducted simulation experiments to validate the approach. In the experiments, we consider three cases to evaluate the performance of the approach using clocks with different stabilities, namely, the frequency stabilities of the clocks equipped at three selected ground stations are respectively (Case 1), (Case 2), and (Case 3) at time period. Conclusions are drawn from the experimental results. First, high-precision clocks can significantly improve the accuracy for PPP time transfer, but the improvement is limited by measurement noises. Compared to Case 1, the long-term stabilities of OPMT-BRUX as well as PTBB-BRUX are improved in Cases 2 and 3. The frequency stabilities of Cases 1-3 are approximately 4.28*10-16, 4.00*10-17, and 3.22*10-17 at 10-day averaging time for OPMT-BRUX, respectively, and for PTBB-BRUX, these values are approximately 3.73*10-16, 8.17*10-17, and 4.64*10-17. Second, the geopotential difference between any two stations can be determined at the decimeter level, with its accuracy being consistent with the stabilities of the time links in Cases 1-3. In Case 3, the determined geopotential differences between OPMT and BRUX deviate from the EIGEN-6C4 model values by -0.64 m2/s2 with an uncertainty of 1.11 m2/s2, whereas the deviation error between PTBB and BRUX is 0.76 m2/s2 with an uncertainty of 1.79 m2/s2. The approach proposed in this study can be also applied to testing GRT.
