Polarized Imaging Research Based On Monte Carlo Method

Polarized Monte Carlo imaging method has been developed due to the improvement of modern computers' processing capacity and running speed,besides the appearance of more sophisticated and accurate detection equipment.It is widely applied into the areas such as the simulation of optical target detecting and tracking,abnormal tissues locating and pathological analysis as well as environmental quality monitoring and so on.As a pretty efficacious kind of numerical method,polarized Monte Carlo imaging method now is becoming increasingly ameliorated and accelerated.Hence it is of great importance to do the research on Monte Carlo imaging method for target locating,oceanic resource exploration and human health.We studied the optical imaging process in order to improve the quality of our imaging results,the major work is as follows:We have discussed both H-G phase function method and rejection method to select scattering angle and azimuth angle,Euler method,meridian plane method and quaternion method to provide a reference coordinate to the stokes vector.Moreover,in order to speed up this time-consuming simulation method,we introduced three kinds of accelerating strategies: white Monte Carlo method,perturbation Monte Carlo method and optimized Monte Carlo method.We compared a quantity of tests that were carried out for the purpose of imaging optimization,including active imaging,passive imaging,time-flight imaging.Also,there were the examples adopting different light sources: neutrons,infrared light,X-ray etc.Different from the traditional intensity imaging,polarized Monte Carlo method makes full use of the advantages of computational technology and the optical information taken along by incident photons.We have established it according to the elementary six procedures of Monte Carlo imaging method.But when the medium becomes more turbid,it will be difficult to attain an image satisfying our requirements.Here we introduced and developed a new kind of polarized retrieving Monte Carlo imaging method to improve the imaging contrast and detection depth.And the effective plane Mueller matrix was attained by superposition principle.We have made imaging contrast which acted as the criteria of imaging quality a function of scattering particles' number density,complex refraction and incident photons' degree of polarization.The results showed that circularly polarized incident light behaved better than linearly polarized incident light in both haze and sea environment.The variations of scattering particles' number density and complex refraction would lead to the changes of seawater optical properties.Moreover,polarized retrieving Monte Carlo imaging method could achieve much higher imaging quality than intensity imaging method under oceanic environment.