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Abstract

Currently, the Borowa Gora Geodetic-Geophysical Observatory maintains 3 modern gravity sensors: A10-020 (since 2008), iGrav-027 (since 2016) and AQG-B07 (since Oct. 2021).Although the instruments considered measure the same phenomena, each of them is based on a different principle of measurement. The presentation aims to evaluate the pros and cons of each gravimeter with respect to the other two by assessing certain characteristics of the instruments (long-, short-term stability, repeatability, noise level). Using AQG and iGrav gravimeters jointly allow to verify their performance in a period of instrumental service/updates, i.e. running continuous gravity measurements while the other gravimeter was maintained.During the period from Oct 2021 until mid-2023 all instruments have been performing regular gravity surveys within their recording capabilities, i.e. the A10-020 on regular monthly basis, the AQG-B07 on regular monthly, sub monthly basis as well as periodic longer tracking series and the iGrav-027 in continuous mode.As the AQG-B07 is the newest type of instrument its performance seems the most interesting. During the presented period AQG showed consistency in tracking gravity variation against the iGrav-027 gravimeter on a few tens of nm/s² in long term (within a year), and below 10 nm/s² in short term comparison (couple of weeks of joint gravity measurements). Systematic gravity difference between AQG-B07, A10-020 and reference function realized by the iGrav-027 gravimeter will be discussed. AQG-B07 systematic effects as well as Total Uncertainty is under constant evaluation by iXblue - the gravimeter manufacturer.