ABSTRACT We present experimental results on the relationship between rain attenuation and simultaneous scintillation during rain events, based on beacon signal measurements at 19.7 (Ka‐band) and 39.4 GHz (Q‐band) from the geosynchronous Alphasat satellite (25° E), received at two Italian ground stations, Spino d'Adda (42.1° slant path) and Tito Scalo (35.5° slant path). Time series data collected between 2015 and 2023 were processed at 16 Hz and filtered to isolate rain attenuation and scintillation components using fixed low‐pass (0.05 Hz) and a band‐pass (0.175–3 Hz) filters, respectively. The average rain attenuation (dB) and the average scintillation standard deviation (dB), computed in 1‐min intervals, were found to follow a power‐law relationship of the form and , consistent with a thin turbulent layer. The models were fitted to the data over the attenuation range = 1.0–15.0 dB, where system noise has minimal influence, and their performance evaluated using mean squared error. The modified thin‐layer model showed the best agreement overall, with lowest MSE values found when fitting the model to the Tito Scalo Ka‐band and Spino d'Adda Ka‐ and Q‐band data. Additionally, to demonstrate the thin‐layer model's effectiveness, the models are examined briefly when frequency scaling the behavior of scintillations from 19.7 to 39.4 GHz. Among the models tested, the modified thin‐layer model provided the best match to observed measurements when scaling. These results indicate that thin‐layer turbulence models provide a physically consistent framework for characterizing rain‐conditioned scintillation during rain events.
Turner et al. (Thu,) studied this question.