Comparative analysis of local angular rotation between the Ring Laser Gyroscope GINGERINO and GNSS stations

The study of local deformations is a hot topic in geodesy. Local rotations of the crust around the vertical axis can be caused by deformations. In the Gran Sasso area the ring laser gyroscope GINGERINO and the GNSS array are operative. One year of data of GINGERINO is compared with the ones from the GNSS stations, homogeneously selected around the position of GINGERINO, aiming at looking for rotational signals with period of days common to both systems. At that purpose the rotational component of the area circumscribed by the GNSS stations has been evaluated and compared with the GINGERINO data. The coherences between the signals show structures that even exceed 60$\%$ coherence over the 6-60 days period; this unprecedented analysis is validated by two different methods that evaluate the local rotation using the GNSS stations. The analysis reveals that the shared rotational signal's amplitude in both instruments is approximately $10^{-13} rad/s$, an order of magnitude lower than the amplitudes of the signals examined using the coherence method. The comparison of the ring laser data with GNSS antennas provides evidence of the validity of the ring laser data for very low frequency investigation, essential for fundamental physics test.