The Monte-carlo Simulation Of The Influences Of The Atmosphere Attenuation For Lidar

The lidar has reached a maturity stage from the exploration stage in twentieth century. As opposed to the microwave radar, millimeter wave radar, the migrate of the word band make lidar process a lot of advantages, however, some shortcomings are followed, such as severe atmosphere attenuation. So it is becoming more important that study on the atmospheric attenuation. Currently, most of the study of the atmospheric attenuation are based on the calculation software and some experience formula. This method is convenient in a normal visibility but in a poor visibility, although some data has been storen in the software packet but not comprehensive, particularly in a poor visibility, the experical formula and concluded with the experimental results will be obvious deviation. However the Monte-Carlo method will make the attenuation of laser more close to the real situation in a poor visibility. IFirst of all, in this paper, the main methods, that is Monte-Carlo method is introduced. After medeling, we got some difference from the result of experience fomula in a poor visibility by the computer simulation, and we found that Monte-Carlo method that consider the multiple scattering is more realistic. Second, after the dissicussion of the decay of the laser by the aerosol, we use the Monte-Carlo method to the specific issues, calculate the affection to the backward scattering by the optical parameter, it is very serious of the affection of the atmospheric attenuation coefficient, particle albedo and other optical parameters to the backscattering. The atmospheric backscatter power increases with distance, and tends to smooth state finally. n normal visibility, by calculate the power of backscattering, response power of the receiver would be decided to improve the SNR. In a poor visibility conditions, backscattering power may completely cover the target echo return signal. We got response time in different optical parameters by calculation and it will have some guidance to the selection of the range gate width.