Using Microcontrollers to Create Portable, Self-Contained Seismic Sensors

Seismic sensors can be used for a wide variety of applications, including vibration monitoring, near-surface imaging, and horizontal to vertical spectral ratio (HVSR) techniques (e.g. sediment layering and seismic zoning). Unfortunately, professionally developed and engineered seismic sensors are typically expensive, which can make them inaccessible to engineers and researchers without financial resources, such as those in developing countries. As an alternative to these professional, but expensive instruments, we have developed a seismic sensor using a microcontroller that is much more affordable and can perform many of the same applications as the more traditional, professional systems. Our system uses a microcontroller paired with a 24-bit analog to digital converter (ADC) to record seismic signals from three orthogonal axes with an effective resolution of 5 μV and sampling rates up to 250 Hz. In addition, a GPS module is used to record the location (GPS coordinates) of the sensor and to correlate the recorded signals with real time so that signals collected by individual sensors may be meaningfully combined to create sensor arrays.