Abstract
We have performed the gravitational redshift measurement by using a pair of transportable optical lattice
clocks located on the ground floor and on the observatory floor of the Tokyo SKYTREE, separated by an
altitude of 450 m. We have observed a corresponding gravitational redshift of 21.1771(18) Hz. By comparing
the observed shift with the predicted gravitational redshift by general relativity, evaluated using
the measurements of global navigation satellite system, spirit leveling, laser ranging and gravity, the deviation
of the observed gravitational redshift is found to be α = (1.3 ± 9.1) × 10−5, which is two-orders of
magnitude better than any other ground-based experiments and is comparable with the findings of space
borne experiments.
