A new high-precision gravity solid tidal model for Precision Gravity Measurement Facility

It is significant for establishing gravity datum to construct precise gravity solid tidal model. A simple method with relatively low performance is to interpolate tidal parameters from the global gravity solid tide models. A competitive approach is to determine local gravity solid tidal model by harmonic analysis using long-time serial gravity observations. In this paper a new high-precision gravity solid tidal model for Precision Gravity Measurement Facility is estimated from two co-site gravimeters in the cave laboratory using modern international standard data processing techniques, whose accuracy is evaluated further by comparing with previous publications. The results show that: (1) the determined gravity solid tidal models from two co-site gravimeters are in good agreement with each other, of which the maximum differences for amplitude factors and phase delays don't exceed 0.01700% and 2.50990°, respectively. (2) the performance of the obtained gravity solid tidal model is 0.00411 for amplitude factors and 0.24120° for phase delays, which is a little better than that of previous publications using superconducting gravity data from Wuhan station. (3) our results and methods are corrective and effective. (4) our model is tiny different from that provided by Wuhan station, which implies that it is necessary to construct a gravity solid tidal model for Precision Gravity Measurement Facility, rather than just adopting existing models at Wuhan station. Our results are helpful in realizing the goal of Precision Gravity Measurement Facility.