No abstract

Digital sensors based on micro electro mechanical systems (MEMS) accelerometers are one of the newest technologies being used in seismic acquisition. As such, some confusion remains surrounding similarities and differences relative to the coil-over-magnet geophone. An understanding of the functioning of these sensors and how to compare them can be facilitated by deriving transfer functions, which relate the data acquired through each sensor to actual ground motion.An equation is then derived to calculate acceleration comparable to unprocessed MEMS data from unprocessed geophone data. The inverse of this equation may be used to calculate geophone data from MEMS data.The effects of sensors on zero and minimum phase wavelets are modeled, demonstrating that the raw output from the sensors should be similar. The minimum phase wavelets are convolved with a random reflectivity series to test deconvolution of impulsive source data. Deconvolution produces geophone and MEMS processed traces that appear similar, and constant phase rotation of MEMS data after deconvolution cannot correct all remaining differences.The geophone-to-MEMS transfer equation will exactly transfer between sensors only in the absence of instrument noise. Comparisons between MEMS and geophones recording the same shots, and ground motion domains calculated from those records, show that the data is very similar in frequency content when the same domain is considered, and MEMS records will not necessarily have a larger magnitude contribution from low frequencies than geophones.

No abstract

No abstract

No abstract