Propagation Measurements at 19.7 and 99 GHz Using Ground-Based Radiometers

Radiometers are commonly used in order to assess the atmospheric propagation channel under low-attenuation and scatter-free conditions, with an increasing tendency toward using millimeter frequencies. In this letter, the interest is concentrated on the analysis of atmospheric attenuation measurements simultaneously obtained, under clear sky and the presence of clouds, by two independent and colocated ground-based radiometers at 19.7 and 99 GHz, in April of 2012 in Madrid, Spain. The experimental results obtained are in agreement with the estimations based on vertical meteorological profiles, and it is relevant to mention the high sensitivity to cloud liquid water provided by the measurements at 99 GHz. In general, the perspective of this work points toward the validity of using millimeter radiometry in propagation applications.