Spatial detection of water containing objects in soil using THz radiation.

The detectability of a water-containing object in sand with THz radiation was investigated as a function of the grain size of the material. The investigated frequency range of the spectrometer was between 258-375 GHz. The grain size was between 20-1250 μm. The thickness of the sand in front of the object was 7 mm. With increasing grain size the spatial resolution of the object covered by sand decreased significantly. Independent of the grain size, the object was always clearly detectable. Further information on the experimental setup, materials and measurement data can be found in the supplementary information. Data can be downloaded here: https://b-web.bonares.de/smartEditor/rest/upload/ID_3006_2020_1_20_I4S_Mahns.zip