Fig. 1. Atmospheric environment simulation cabin of the interior (a) and exterior (b) physical figure

Fig. 2. Aerosol inlet in the simulation chamber (a) and axial fan and ventilation ducts (b)

Fig. 3. Aerosol particle number concentration varies with time. (a) 0.35 μm; (b) 0.50 μm; (c) 0.70 μm; (d) 1.00 μm; (e) 2.00 μm; (f) 2.50 μm

Fig. 4. Simulation cabin extinction coefficient and visibility changes over time

Fig. 5. The mean spectral distribution of aerosols in simulate chamber. (a) Number concentration spectrum; (b) surface area spectrum; (c) volume spectrum

Fig. 6. Comparison curve of aerosol measured mean spectral distribution and piecewise fitting spectral distribution of each particle size interval. (a) r ≤ 0.45 μm; (b) 0.45 μm < r ≤ 0.8 μm; (c) r > 0.8 μm; (d) full particle size interval

Fig. 7. Correlation analysis of different methods fitting spectra and observation spectrum. (a) Junge spectrum fitting; (b) Deirmendjian spectrum fitting; (c) this paper's method fitting

Fig. 8. Correlation curves between calculated and measured visibility values

Fig. 9. Consistency test of each fitting method for low visibility below 2 km. (a) Junge spectrum; (b) Deirmendjian spectrum;(c) piecewise fitting spectrum