Calibration of a superconducting gravimeter by comparison with an absolute gravimeter FG5 in Boulder

This paper reports the results of a calibration of a superconducting gravimeter using simultaneous measurements of Earth tides with an absolute gravimeter. Nine consecutive days of observations were made with both the C024 superconducting gravimeter and the FG5‐202 absolute gravimeter at the NOAA Table Mountain Gravity Observatory near Boulder, Colorado. The precision of the calibration factor is better than 0.1%. The calibration factor obtained in this fashion agrees well with that obtained from a moving platform. This experiment provides a noise estimate for both the superconducting and absolute gravimeter. In addition, the local air pressure admittances of both instruments compare well with a value close to −0.35 µGal/mbar.