Small seismic sensors are routinely used for the purpose of border control, civilian and government security, geological research, asset protection, and many other applications which can gain insight from sound waves propagating in the earth. However, placing seismic sensors in the ground and recording seismic events provides only data. To yield information, that data must be correlated with known seismic signatures which provide the knowledge that the vibration is a single individual versus a group of people or small herd of animals. Complicating all of this is the fact that seismic sensors are placed in soil that differs from one foot to the next, such that the waves propagating within the soil vary from location to location. A better understanding of seismic response variability for different soil profiles, geological conditions, environments, and climates – all of those instances that occur outside of the laboratory – is needed.
To address the above, Army researchers have developed a more real-world test chamber for characterizing soil conditions and testing seismic monitors. The test chamber allows seismic system designers to test instruments under variable soil conditions such as soil type, fluid flow and drainage, moisture levels, compactness, and other variables that affect seismic wave propagation.
- A seismic wave is propagated through the test chamber by piezoelectric transmitters and measured with a resistivity sensor
- A fluid system allows for precise control of placement and amount of water in the test chamber and simulates meteorological conditions but does not exert a force on the soil sample
- Six UNITs have been built and are in use by Army researchers
- US patent 9,606,087 available for license
- Potential for collaboration with Army researchers