Experimental evaluations of polarimetric observation for bistatic radar using GPS reflected signals

In this paper, as a pilot experiment of bistatic polarimetry using a ground-based antenna, polarization states of reflected Global Positioning System (GPS) signals are investigated. The Stokes parameter of the reflected wave is calculated by power measurements with a dedicated multi-pol short backfire antenna. Then the degree of polarization (DoP) is estimated with the acquired Stokes parameter. A soil platform of which the surface is changeable from bare soil to imitated vegetation is prepared. Under these environments, relationships between the DoP and bistatic configurations or a variety of targets are examined. Also maximum likelihood estimation of the DoP is tried using two measured intensity of six polarizations.