Long-term statistics of tropospheric attenuation from the Ka/U band ITALSAT satellite experiment in the United Kingdom

摘要

Long-term statistics of tropospheric attenuation were derived from almost 4 years of measurements made in the south of England using the ITALSAT F1 beacon signals at 49.5, 39.6, and 18.7 GHz; coincident rainfall rate measurements were made at the site of the receiving ground station. A method to remove the nonatmospheric changes of the beacon signals and to establish the reference levels from which to measure the excess and total attenuation has been presented in detail. The accuracy of fade level retrieval is estimated to be ～±0.5 dB. A new method for predicting the annual total attenuation statistics has been proposed and validated against our data and data collected in Italy at 18.7, 39.6, and 49.5 GHz. For both locations, the new proposed method gives much better predictions compared with the established International Telecommunication Union recommendation method. A significant monthly and seasonal variation was observed in the attenuation and rainfall statistics and should be taken into consideration when planning the design and use of future slant path systems. We have seen that the attenuation statistics are subject to diurnal variations; however, for the period analyzed, this variation does not seem to follow a particular pattern.