Aerosol scattering alters the propagation path of infrared radiation in the atmosphere, causing part of the radiative energy to be redirected and dispersed. This results in attenuation and spatial spreading of the received radiation signal. Consequently, it reduces image contrast and blurs fine details, making aerosol scattering a primary contributor to infrared image degradation. Although the impact of aerosol scattering on imaging has been demonstrated theoretically in previous studies, the extent of its contribution to image degradation in practical scenarios remains controversial. Two main factors contribute to this controversy. First, there is a strong coupling between atmospheric transmission effects and the imaging system's response characteristics. Second, it is difficult to accurately obtain atmospheric environmental parameters. As a result, systematic comparisons and validations between theoretical modeling and field measurements remain limited.

To address these issues, we employed the modulation transfer function (MTF) as a quantitative metric for image quality. Accordingly, we developed an integrated framework combining theoretical modeling and field measurements to analyze the impact of aerosol scattering. A field imaging experimental system was established to acquire target image data along with synchronous meteorological observations. Based on these data, the contributions of system response, atmospheric turbulence, and aerosol scattering were quantified and modeled. For aerosol scattering modeling, scattering and absorption coefficients were first calculated using the MODTRAN urban aerosol model to construct a theoretical aerosol MTF model. However, significant discrepancies were observed between the modeled results and field measurements. To improve modeling accuracy, aerosol optical properties retrieved from CE318 sun photometer observations were further incorporated into the simulation. Furthermore, deviations caused by variations in the imaging system's focus were considered, and the measured aerosol MTF was corrected accordingly, improving the reliability of the experimental results.

The results demonstrate that under low-visibility conditions, aerosol scattering has a significant impact on the modulation transfer characteristics of long-wave infrared imaging systems. The aerosol MTF predicted using CE318-retrieved parameters shows good agreement with experimental measurements, achieving a mean square error of only 1.8%, which significantly outperforms the results based on standard aerosol models. By integrating theoretical modeling with field measurements, this study quantitatively analyzes and experimentally validates the effects of aerosol scattering. These findings reveal the underlying mechanisms of infrared image degradation and ultimately provide a reliable basis for performance prediction and model refinement of infrared imaging systems in complex atmospheric environments.