A landslide prognostication system based on bistatic radar technology using AM radio waves

Propagation characteristics of electromagnetic wave at an interface between the free space and hydrated soil were investigated in order to construct a landslide prognostication system. The prehension on the complex permittivity of the hydrated soil became integral technology, so that the complex permittivity was measured as the function of the water volume content at frequency bands from low frequency (LF) to medium frequency (MF), and the transmission and reflection characteristics of the hydrated soil was calculated based on the propagation model applying the measured complex permittivities. From the result, it is obvious that the reflection from the hydrated soil behaves as a key role to estimate the water content. In addition, the complex permittivities of live and dead leaves, woods and stones were measured and the reflection characteristics of the forest existing on the surface of the land were calculated and evaluated. It is found from the calculated results that their influence is little for the reflection characteristics. Finally, the initial consideration of the landslide prognostication system using the bistatic radar technology was performed.