Determination of gravitational potential and the orthometric height of Mt. Everest using clocks onboard satellite and on ground: preliminary simulation results

Abstract:

Based on our proposed approach (Shen et al 2015) for determining the gravitational potential using high-frequency-stability microwave links between satellite and ground station, here we provide preliminary simulations results. Two precise clocks (oscillators) are equipped onboard a satellite and at a ground station, respectively. The ground oscillator emits a signal with frequency fa towards the satellite and the satellite receiver receives this signal with frequency fb. After receiving this signal, towards the ground station the satellite oscillator emits two signals which have the frequencies fb and fc, respectively. By a combination of these three frequencies based on Doppler cancelation system, the gravitational potential difference between the satellite and the ground station can be determined. Concerning a datum station and a station at Mt. Everest, we may determine the geopotential difference between these two stations via a satellite, and consequrently determine the orthometric height of Mt. Everest. In the simulations, we use 9000 observations (a length of about 2hrs observations), and results show that most offset values are in the order of 0.1 m (in equivalent height). The mean value of the differences is -0.008 m, and standard deviation is around 0.3 m. Since atomic clocks with stability around 10E-18 have been generated, the proposed approach is prospective in the near future. This study is supported by National 973 Project China (grant No. 2013CB733301 and 2013CB733305) and NSFC (grant Nos. 41174011, 41210006, 41429401).