The Monte Carlo Study Of Polarized Light Propagation In Atmosphere: Simulation And Application

There has been a great achievement in obtaining information of atmosphere by use of the polarization characteristic in recent years. To enhance the security in general ultraviolet communication and increase the distance of target recognition, we provide a theoretical model in this thesis. Results drawn form this model have a significant effect on guiding the research in atmosphere.The component characteristic of particles in atmosphere is discussed particularly in the thesis. And the propagation of signal is described by analyzing the scattering effect between atmospheric particles and photons. Then we make a detail comparison between several numerical solution methods used in solving radiative transfer problem and find that the Monte Carlo method has an intrinsic advantage than others.A Monte Carlo model of polarized light transmitting in atmosphere is present by use of the Stokes/Mueller formalism and Meridian planes method. Then an experiment is designed to record the backscattering Mueller matrix patterns of the polystyrene-sphere suspension. We find that the simulated results are the same as the experiment ones.Based on the above model, bit error rate (BER) and search complexity (SC) which determine the polarization bases are simulated with different particle sizes, communication distances and elevations. Results show that the third factor plays a more important part than the former two in the choice of polarization base number. Low BER Non-line-of-sight (NLOS) ultraviolet quantum communication can be realized only in system where transmit and receive elevations are small.Three different methods used for target recognition in turbid atmosphere are simulated. Results show that the DOP recognition has a better performance than the intensity and degree of depolarization (DOD) measurements. The best choice of wavelength for target recognition is also discussed in this thesis.In a word, a detail discuss in the application of polarized light transport in atmosphere is present in this thesis. Simulation results show that the DOP method can solve the above problems well. A few results have never been seen in other papers.