The selection of sites for underground gravitational wave detectors based on spectral and cumulative characterisation of the low frequency seismic noise. The evaluation of the collected long term seismological data in the M\'atra Gravitational and Geophysical Laboratory revealed several drawbacks of the previously established characteristics. Here we demonstrate the problematic aspects of the recent measures and suggest more robust and more reliable methodology. In particular, we show, that the mode of the data is noisy, sensitive to the discretization and intrinsic averaging, and the rms2Hz is burdened by irrelevant information and not adapted to the technological changes. Therefore the use of median of the data instead of the mode and also the modification of the frequency limits of the rms is preferable.
@article{arxiv.1810.06252,
title = {Seismic noise measures for underground gravitational wave detectors},
author = {L. Somlai and Z. Gráczer and P. Lévai and M. Vasúth and Z. Wéber and P. Ván},
journal= {arXiv preprint arXiv:1810.06252},
year = {2019}
}