Forward scatter polarimetric measurements of terrain at 35 and 225 GHz

This thesis describes ground based measurements of the forward scatter characteristics of a variety of terrain. The system used to make these measurements is a truck based system of two radars at 35 GHz and 225 GHz. The 35 GHz radar is a coherent polarimeter, while the 225 GHz polarimeter is a non-coherent system. These radars are mounted on an antenna positioner in a truck based platform. These forward scatter measurements are made using a novel configuration where a trihedral corner reflector, located opposite a co-located receiver and transmitter, is used to reflect the transmitted pulse back to the receiver. Therefore the current monostatic configuration of the radars does not need to be modified and alignment problems are reduced. The measurements covered in this thesis are near-grazing measurements. These measurements are generally more difficult to make due to undulations of the ground. This thesis provides a summary of the radar systems, including recent improvements, and operational principles of polarimetry including an analysis of the calibration and data processing. Finally, the experiments in and around Amherst, Massachusetts are presented along with comparisons to a variety of scattering models. The most promising of which is an integral equation model which matches very well to the measured data. Also, the thesis describes a technique to determine the amounts of and separate the diffuse and specular components of forward scatter and furthermore separate the two components