Phenomenology of Fully Polarimetric Imaging Radars

We have previously reported on the analysis of fully polarimetric single look and multilook SIR-C data. We have reported that the Stokes(Kennaugh) matrices for each pixel have one and only one eigenvector that satisfies the property of a Stokes Vector. We now report on new analysis of fully polarimetric SIR-C data and ISAR data from the Submillimeter-Wave Technology Laboratory at the University of Massachussetts Lowell which shows that the remaining three eigenvectors of the Stokes matrix are quaternions which represent rotations. Furthermore, the three direction vectors of these quaternions form an orthogonal cartesian set of axes. We also discuss relationships between the angles of the Stokes Vector with the Euler parameters initially proposed by Huynen.