A study on light extinction model and inversion of mixed particle system based on Monte Carlo method

The extinction characteristics of mixed particles, which are composed of various types of particles, appear to be more complex. To statistically analyze photon destinations and investigate the extinction characteristics of mixed particles by tracing all underlying events in detail, a Monte Carlo method-based extinction model has been developed. Meanwhile, an extinction spectrum measurement system was designed. A series of experiments for both single-type particle and mixed-particle systems were performed. Afterwards, global optimization algorithms are introduced to perform simultaneous inversion of sizes of mixed particles and mixing ratio based on the experimental spectrum. The inversion results show that the error for any single parameter is <2%. Performing a simultaneous inversion for particle sizes and mixing ratios leads to an increase in the relative error, but it does not exceed 9%. It indicates that the model could simultaneously invert the mixing ratio and handle particle systems with two different sizes.