# Tidal Effects and Clock Comparison Experiments

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## Abstract

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## 1. Introduction

## 2. Clock Comparisons in the General Relativity Reference Systems

#### 2.1. Tidal Potentials and Clock Comparison

#### 2.2. Clock Comparison in the Barycentric Coordinate Reference System

#### 2.3. Clock Comparison in the Geocentric Coordinate Reference System

## 3. Experimental Estimation for Tidal Effects

## 4. Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 1.**The calculated frequency shift for a clock comparison in laboratory. The curve represents the fractional frequency shift between $\mathcal{A}$ (E${114}^{\circ}$, N${30}^{\circ}$) and $\mathcal{B}$ (E${1116}^{\circ}$, N${40}^{\circ}$) due to tidal potentials.

**Figure 2.**The calculated frequency shift for a clock comparison between laboratory and space. The curve represents the fractional frequency shift between the $\mathcal{B}$ clock and the China space station clock due to tidal potentials.

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**MDPI and ACS Style**

Qin, C.-G.; Liu, T.; Dong, J.-Z.; Dai, X.-Y.; Tan, Y.-J.; Shao, C.-G.
Tidal Effects and Clock Comparison Experiments. *Universe* **2023**, *9*, 133.
https://doi.org/10.3390/universe9030133

**AMA Style**

Qin C-G, Liu T, Dong J-Z, Dai X-Y, Tan Y-J, Shao C-G.
Tidal Effects and Clock Comparison Experiments. *Universe*. 2023; 9(3):133.
https://doi.org/10.3390/universe9030133

**Chicago/Turabian Style**

Qin, Cheng-Gang, Tong Liu, Jin-Zhuang Dong, Xiao-Yi Dai, Yu-Jie Tan, and Cheng-Gang Shao.
2023. "Tidal Effects and Clock Comparison Experiments" *Universe* 9, no. 3: 133.
https://doi.org/10.3390/universe9030133