Measurement of atmospheric particle number density fluctuations based on moiré deflectometry

Abstract

ObjectiveIn this paper, moiré deflectometry is introduced to measure the atmospheric particle number density fluctuations to expand the application field of the technology. MethodsThe relationship between the atmospheric particle number density fluctuation and the refractive index fluctuation is established, which provides a theoretical basis for obtaining the atmospheric particle number density fluctuations by moiré deflectometry. To verify the feasibility of this method, two sets of experiments which lasted two hours were executed. In experiments, the moiré fringes are recorded at a frequency of one frame per second. Therefore, 7200 arrival angles could be obtained for each experiment. ResultThe results show that the atmospheric particle number density fluctuations experimentally obtained by moiré deflectometry basically match well with those of calculated by theoretical estimation, which means that it is feasible to introduce moiré deflectometry into the measurement of atmospheric particle number density fluctuations. In a word, this research could provide some reference for studying the influence of atmospheric refractive index fluctuation on optical detection and communication.