V.F. Fateev

FSUE “VNIIFTRI”, Mendeleevo, Moscow region, Russia
generalfat@mail.ru

Al’manac of Modern Metrology № 2 (34) 2023, pages 65–87

Abstract. The relativistic effects of the frequency shift of the driving generators and time scales of onboard microwave quantum clocks placed on board of low-altitude geodetic satellites are considered in the article. The first task of the study was to determine the daily discrepancy of the time scales of onboard and ground quantum clocks, the second was to determine the relativistic frequency distortion of the driving generators of highly stable quantum clocks, which is important from the point of view of ensuring high accuracy of Doppler measurements of radial velocity along the downlink and uplink. It is shown that the frequency of the driving generator of the onboard quantum clock at an orbital altitude of about 1 thousand km is less than the frequency of the driving generator of the base clock by an amount in relative terms –2.011 · 10^–10. Accordingly, the onboard clock run behind the base, and the rate is –17.4 microseconds/day. The influence of the second zonal harmonic of the Earth’s gravitational potential appears in the form of a linear component (+66 ns/day) and a periodic component (the total excursion is 0.38 ns). Methods of correction of the onboard time scale are proposed. The errors of Doppler radial velocity measu­rements for GEOIC and DORIS systems are determined: in both cases the relativistic error of the determination of the radial velocity is 12 cm/s.

Keywords: geodetic satellites, relativistic effects, quantum clocks, time scale correction, rela­ti­vistic radial velocity errors.

Full texts of articles are available only in Russian in printed issues of the magazine.