Geopotential Determination Between Ultra-Stable Distant Clocks Based on Two-Way Space Laser Time Transfer Links
- 1Time and Frequency Geodesy Center, School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China.
- 2State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China.
- 3Department of Surveying Engineering, Faculty of Engineering at Shoubra, Benha University, Cairo 11629, Egypt.
- 4Civil Engineering Department, Faculty of Engineering, Minia University, Minia 61111, Egypt.
- 5School of Resource, Environmental Science and Engineering, Hubei University of Science and Technology, Xianning, Hubei, China.
The Earth’s gravity potential (geopotential) field plays an important role in geodesy, for instance, it is the basis for defining the geoid and the International Height Reference System (IHRS). In chronometric geodesy, the main challenge for directly measuring geopotential differences between two stations lies in that a reliable link for time comparison is needed. Currently, most satellite links for time comparison are dealt with in the microwave domain, for which the ionospheric and tropospheric effects are major error sources that greatly influence the signal propagation compared to optical space links. Recently, accurate laser time transfer links between satellite and ground stations have already been planned and confirmed, such as Laser Time Transfer (LTT, China) on BeiDou satellites and Tiangong II / China's space station (CSS), Time Transfer by Laser Link (T2L2, French) on Jason-2 mission and European Laser Timing (ELT, Europe) on Atomic Clock Ensemble in Space (ACES). Therefore, in this study, we propose an approach for determining the geopotential difference between two ground atomic clocks based on the Two-way Laser Time Transfer (TWLTT) technique via a space station as a bridge, which could have potential applications in geoscience. This study is supported by the National Natural Science Foundations of China (NSFC) under Grants 42030105, 41721003, 41804012, 41631072, 41874023, Space Station Project (2020)228, and the Natural Science Foundation of Hubei Province of China under Grant 2019CFB611.
How to cite: Ruby, A., Shen, W.-B., Shaker, A., Ashry, M., Pengfei, Z., Rui, X., Shen, Z., and Xu, W.: Geopotential Determination Between Ultra-Stable Distant Clocks Based on Two-Way Space Laser Time Transfer Links, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1378, https://doi.org/10.5194/egusphere-egu21-1378, 2021.
