System Performance in Rain in a Radome-Enclosed Environment

A Drop Size Distribution (DSD)-Based Model for Evaluating the Performance of Wet Radomes for Dual-Polarized Radars

“…Before the existence of repellent materials, the attenuation of a wet radome was evaluated based on the water layer thickness using Gibble's formulation (Gibble 1964;Blevis 1965), which assumes that formation of water on a radome consists of a thin film of water. Later experimental results by Anderson (1975) and Chang (1985) show a significant difference between their experimental results and theoretical results based on a laminar flow model proposed by Gibble (1964). Anderson's results suggest the discrepancies could be attributed to two factors.…”

“…However, for higher frequencies water formation on the radome surface can significantly deteriorate the transmit and receive signals. The attenuation of radio signals on satellite systems that operate between 17 and 22 GHz has been extensively analyzed in the past regarding the large attenuation in the radio signals caused by water accumulation on the radome surface (Gibble 1964;Blevis 1965;Cohen and Smolski 1966;Anderson 1975;Hendrix et al 1989;Chang 1985;Fenn 1997;Crane 2002).…”

“…To evaluate and characterize the wet radome performance, experimental measurements are the most reliable method of determining the signal attenuation in a radar or communication system. In addition to Chang (1985), Hendrix et al (1989), Fenn (1997), and Merceret and Ward (2002) proposed an Merceret and Ward (2002) empirical formulation to estimate the two-way losses of a hydrophobic radome as a function of the rainfall rate, frequency, and a constant that depends on the hydrophobic material used. The computed two-way losses for S-and C-band radars indicate an improvement factor of 3 in two-way attenuation when a hydrophobic coating is added on the radome surface.…”