  Signal-to-noise ratios are a widely used concept for astroparticle radio
detectors, such as air-shower radio arrays for cosmic-ray measurements or
detectors searching for radio signals induced by neutrino interactions in ice.
Nonetheless, no common standards or methods are established for the
determination of the signal-to-noise ratio: values cannot be compared between
experiments, and for the same signal and noise, various methods differ by large
factors on the signal-to-noise ratio. This was the motivation to discuss a
community-specific standardization at the ARENA conference 2022. No agreement
on a common method to calculate signal-to-noise ratios was reached, however,
awareness was raised that signal-to-noise ratios need to be well defined in any
publications. This includes providing sufficient information on the procedure
used to determine the signal-to-noise ratio, in addition to simply stating the
formula. Even when using the same definition of the signal-to-noise ratio,
there is still a significant dependence on the procedure of calculation, e.g.,
the signal-to-noise ratio of waveforms containing only background can vary
significantly depending on the size of the time interval used as signal search
window. To facilitate the interpretation of any signal-to-noise ratios in a
specific study, the recommendation is to also state the mean value of the
signal-to-noise ratio that the used method yields when applied to noise used in
the study, e.g., the radio background measured by the corresponding experiment.
