Gravitational redshift test using Rb clocks of eccentric GPS satellites

Loghman Fathollahi; Falin Wu; Barbara Pongracic

doi:10.1016/j.heliyon.2023.e13178

Gravitational redshift test using Rb clocks of eccentric GPS satellites

Heliyon. 2023 Jan 24;9(2):e13178. doi: 10.1016/j.heliyon.2023.e13178. eCollection 2023 Feb.

Authors

Loghman Fathollahi¹, Falin Wu¹, Barbara Pongracic²

Affiliations

¹ SNARS Laboratory, School of Instrumentation and Optoelectronic Engineering, Beihang University, Beijing, China.
² iOLAP, Inc., Rijeka, Croatia.

Abstract

This paper reports a test of gravitational redshift, which is a consequence of the Einstein equivalence principle, using the Rb clocks of GPS Block IIF satellites. The fractional deviation in the gravitational redshift was measured using 6,640 days of data from three Rb clocks onboard GPS Block IIF satellites. The systematic effects related to orbital uncertainty, temperature, and magnetic field were modeled conservatively. The fractional deviation in the gravitational redshift from the general relativity prediction was measured with $(0.23 \pm 1.34) \times 10^{- 3}$ at one sigma.

Keywords: GPS; Gravitational redshift test; Local position invariance; Rb clocks.