In my research, finding and understanding info relating to the lower end of (conventional) surface seismic data acquisition (i.e. 15 - 1 Hz) is relatively simple. However, when I look at specs for a given type of common geophone, signal at and beyond 100 - 120 Hz is not really commented on or ignored altogether. Indeed, it seems that knowing what is real or usable on the upper bandwidth limits of sensors is left alone for reasons I can't fathom.
In light of this, how can we reliably claim that data beyond the upper bandwidth limit of a sensor is usable? For example, I recently read a MASW-related paper ("Enhancing the High-Frequency MASW Method") that used 40-Hz sensors for the study and - as part of the conclusions - declared that "It is remarkable that all dispersion curves curves can be identified up to 1,600 Hz..." Perhaps this is true but I want the proof to support it.