Stacheder, M. / Koeniger, F. / Schuhmann, R. / Brandelik, A. / Schmitt, G. / Sommer, W. / Fiel, R. (2008): „A new sensor for the automatic detection of the state of ground“. In: Near Surface Geophysics 6 (2008), 67-70

The following paper reports on the development and field test of a new sensor for the determination of the state of ground according to the codes established by the Deutscher Wetterdienst (German Weather Service, DWD). Based on the requirements of the DWD and the results of a feasibility study, an electromagnetic technique was used to design a measurement system which allows for the detection of different soil surface states, such as dry, moist, wet, frozen or snow-covered by evaluating the dielectric properties of the soil and its cover.

The system consists of an impedance analyser and a 1 m(2) large permeable sensor mat with interlaced electrode cables. The sensor and the device were tested in the field on both naturally undisturbed soil and an artificial concrete surface. The new system proved to be reliable and field-capable. With the help of suitable reference measurements of temperature and precipitation as well as visual observations, a decision matrix with several criteria, such as the measured soil capacitance, temperature and state-of-ground history, could be established.

It allows for the interpretation of the measurements and, hence, an automatic determination of the state of ground. The measurement system presented could be a promising new toot for the automatic characterization of the state of ground, for example for weather forecast and traffic control services as well as for agricultural and forestry applications.