Acoustic/Seismic sensors are more commonly used for geophysical exploration. In PSS, acoustic techniques are typically based on the penetration noise as an implement or penetrometer is forced through the soil.
Measuring soil type and compaction by soil penetration noise; using sensors incorporated in a tillage implement for on-the-go measurements [1] [2], and using acoustic sensors mounted in a penetration cone to monitor soil interaction on the penetrating cone surface [3].
Research.
1. Tekeste, M.Z., Grift, T.E., Raper, R.L., 2002. Acoustic Compaction Layer Detection. Paper No. 02-1089, ASAE, St. Joseph, Michigan.
2. Liu, W., Gaultney, L.D., Morgan, M.T., 1993. Soil Texture Detection Using Acoustic Methods. Paper No. 93-1015, ASAE, St. Joseph, Michigan.
3. Villet, W.C.B., Mitchell, J.K., and Tringale, P.T., 1981. Acoustic Emission Generated During the Quasi-Static Cone Penetration of Soils, Acoustic Emission in Geotechnical Engineering Practice, Drnevich, V.P. and Gray, R.E., eds, ASTM STP 750, pp. 174-193.