Frequency and polarization characteristics in vegetation for the ground based penetrating radar

Many image sensors such as the camera, the EO/IR (electro-optic infrared), the LADAR (laser detection and ranging) for unmanned vehicle systems have been investigated [1][2]. However, these sensors cannot provide terrain information in vegetation. They recognize the vegetation canopy as a wall. But the unmanned vehicle can go through the low dense vegetation canopy. But, the rock, the stump or the puddle behind the vegetation canopy can be a big obstacle for the unmanned vehicle. So, the foliage penetrating sensor is needed for the unmanned vehicle in vegetation situation. The synthetic aperture radar (SAR) image sensor using the UWB (ultra-wideband) technique can be an appropriate solution for an unmanned vehicle in the field conditions due to the penetrating characteristics of a microwave. This paper deals with the experimental results on microwave penetration and attenuation characteristics in vegetation situation according to its frequency and polarizations.