MEMS for the masses part 2: comparison to geophones in field data
Michael S. Hons, Robert R. Stewart, Donald C. Lawton, Malcolm B. Bertram
Field data from Violet Grove, Alberta are examined to determine under what conditions data acquired through geophones and MEMS is materially different, which is to say under what conditions they do not perform exactly as their response characteristics predict. Both sensors perform very much as expected down to very small excitation magnitudes. Within the smallest amplitudes in the field data, the lower noise floor of the MEMS sensors may be apparent at very high frequencies. The greatest differences between the sensors appear at large amplitudes (i.e. large ground motion). The MEMS appears to record lower amplitudes immediately above the dominant frequencies, and lower amplitudes above 95 Hz. Simple processing applied to the field gathers might demonstrate greater coherence in the MEMS data amongst high frequencies, but results on whether this represents a reflection event is inconclusive.