Abstract: Modulation transfer function (MTF) is an important indicator to evaluate the effect of turbid atmosphere on the imaging quality of objects. Based on the equivalence principle, this paper studies the quantitative relationship between MTF and key atmospheric optical parameters by using the discrete coordinate numerical solution method of radiative transfer and the linear fitting method, and establish the parametric analytical MTF model in turbid atmosphere. The results have revealed that in the range of optical thickness 0.1–1.0, single scattering albedo 0.1–1.0, and asymmetry factor 0.05–0.95: 1) As for the factors affecting the critical frequency, optical thickness is the largest, followed by scattering albedo, and asymmetry factor is the smallest. 2) In termes of factors affecting MTF, in the low spatial frequency range, the optical thickness is the largest, followed by the single scattering albedo, and the asymmetry factor is the smallest; while in the high spatial frequency range, the single scattering albedo is the largest, followed by the optical thickness, and the asymmetry factor is the smallest. 3) The overall average relative error of the established model is less than 8%, and for many practical application scenarios (asymmetric factor ≥ 0.7, single scattering albedo ≥ 0.55), the average relative error of the model is less than 5%.

Key words: atmospheric optics, imaging through turbid media, optical transfer functions, modulation transfer function, radiative transfer