Polarization Theory And Polarization Technique In Array Signal Processing Applications

The signals transmitted and received by radar are electromagnetic waves, as a vector field, in addition to amplitude, frequency and phase, the electromagnetic wave also has an observable physical characteristic- polarization. Polarization information has enormous potential applications in the detection, identification, filtering enhancement of the radar target. This dissertation focuses on the signal processing of the polarization information in the radar echo, including virtual polarization, polarization filter, and parameters estimation to demonstrate the advantages of the used polarization information quantitatively and theoretically. The following parts are including:1. The polarization scattering matrix (PSM) can reflect all the information of the target scattering properties more fully, if the PSM is known, the received power can be obtained under the arbitrary polarization combinations of the transmitting and receiving antennas. In the paper, the polarization characteristics figures of several typical targets are obtained by the polarization synthesis and their polarization properties have a detailed analysis. So it provides a theoretical analysis method for the study of the scattering echo characteristics.2. On the basis of the virtual polarization theory, the target polarization enhancement and the clutter polarization suppression are achieved by using the matching and orthogonality of the virtual polarization. Filtering in polarization domain is investigated with respect to the unknown and time-varying clutter or interference environment. An adaptive recursive filtering algorithm and its performance are researched; a conclusion that the filtering performance relates with the polarization differences of the target and the interference is obtained.3. The paper specially brings forward a scheme that combines adaptive polarization filter and sidelobe canceller to improve the anti-jamming ability, which is rebuilding the auxiliary antenna of the conventional sidelobe canceller system, Theoretical analysis and computer simulation prove that the scheme can overcome the signal effect of the conventional adaptive sidelobe canceller system, and the interference-signal ratio in the auxiliary antenna as well as the performance of the sidelobe canceller can be improved.4. Polarization sensitive array outperforms the common arrays due to the additional polarization information. It possesses strong anti-jamming ability, robust detecting performance, high resolving power and polarization multi-address capability. In the case of time-varying of the characteristic parameters of the space electromagnetic signal and non-stationary of the space electromagnetic environment, the MUSIC algorithm and ESPRIT algorithm are used to separately complete the estimation of dynamic parameters in this paper, which based on the different polarization sensitive array.