Polarimetry: the characterisation of polarisation effects in EM scattering

This thesis is concerned with the development of a general theory for the characterisation of polarimetric scattering problems. Traditionally, two main approaches have been used in the literature: the first based on measurement of the coherent scattering matrix (Jones calculus) and the second on measurement of the wave Stokes parameters (Mueller calculus). This thesis contains three main developments which extend and complement the published work in this area: 1) The representation of nonsymmetric scattering matrices on the Poincare sphere, using an extension of the fork analysis first introduced by Kennaugh. 2) The construction of a geometry based on the Lorentz , transformation for analysing, on the Poincare sphere. The interaction of partially polarised waves with single targets. 3) The reformulation of polarisation scattering problems in terms of a target spinor and associated coherency matrix. This leads to the construction of a target sphere in 6 dimensions analogous to the Poincare sphere in 3 dimensions. This new formulation also leads to the development of a decomposition theorem for dynamic targets based on the eigenvectors of the coherency matrix. This decomposition is more fundamental than that used by Huynen and the two are compared and contrasted. In order to demonstrate main features of the new theory and to highlight its importance to experimental polarimetry, a laser based optical polarimeter was constructed. Results for the measured coherency Matrix obtained for transmission through quarter and half wave plates are presented and analysed using the target spinor theory.