I need an acoustic sensor I can bury to monitor the immediate area acoustically for footsteps. Is it possible to simply bury a microphone and call it a day, or would a more specialized underground acoustic sensor be necessary?
1 Answer
You have already asked a very similar question, and I'll give you the same answer. The common method of detecting footsteps using a detector buried in soil is a seismic sensor cable.
The frequencies of interest for footsteps are much lower than the frequencies picked up by a microphone. The energy you want to detect is not really acoustic, it is seismic. I can assure that if it was as easy as just burying a microphone we would have already done it.
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\$\begingroup\$ A microphone diaphragm is vibrated by sound frequencies through the air. When buried there probably is no air to cause the diaphragm to vibrate. \$\endgroup\$ Commented Jul 13, 2019 at 0:37