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 g ravimeter using simultaneous measurements of Earth tides with an absol ute gravimeter. Nine consecutive days of observations were made with b oth the C024 superconducting gravimeter and the FG5-202 absolute gravi meter at the NOAA Table Mountain Gravity Observatory near Boulder, Col orado. The precision of the calibration factor is better than 0.1%. Th e calibration factor obtained in this fashion agrees well with that ob tained from a moving platform. This experiment provides a noise estima te for both the superconducting and absolute gravimeter. In addition, the local air pressure admittances of both instruments compare well wi th a value close to -0.35 mu Gal/mbar.