Frequency Scaling Model for the Prediction of Total Tropospheric Attenuation Time Series at EHF

Abstract

A frequency scaling model aiming to predict total tropospheric attenuation time series at EHF is presented. One version of the model [total attenuation frequency scaling (TAFS)] is more accurate but, besides the reference attenuation time series at low frequency, it also requires additional ancillary inputs (e.g., radiometric data and information on the raindrop size distribution); a second version (S-TAFS) is simpler, though at the expenses of a slightly worse performance. Both TAFS and simplified TAFS (S-TAFS) first rely on isolating the attenuation induced by different atmospheric constituents, each of which is separately up-scaled to the target frequency. The two methods are tested against a full year of data collected at Ka -band and $Q$ -band at Politecnico di Milano, Milan, Italy, in the framework of the Alphasat Aldo Paraboni propagation experiment. Results indicate that both methods offer a very good accuracy in scaling the total attenuation from Ka- to $Q$ -bands, both in terms of first-order statistics and of time series. This corroborates the use of TAFS and S-TAFS to predict the total tropospheric attenuation at much higher frequency bands (e.g., the $W$ -band), for which no measurements are currently available, starting from the largely available Ka -band measurements.