Propagation measurements using ITALSAT beacons together with associated measurements of radar reflectivity from rain and clouds at 3 GHz and 35 GHz

This paper gives some preliminary analyses of beacon measurements near 40 and 50 GHz in comparison with radar soundings at both 3 and 35 GHz along the path to the satellite. Two events are analysed, one occurred on 19/9/96 and the other on 30/9/96. This work forms part of a general programme to evaluate the effects of rain, cloud and atmospheric gases on radiowave propagation along Earth-space paths in the 30 to 50 GHz band. It constitutes an extension of the results presented at 1CAP'95 by Ventouras et al. (see ICAP'95, IEE Conf. Pub.407, p.27-31) for the 12 to 30 GHz band using emissions from the Olympus satellite. The investigations in the higher band, particularly for 40 to 50 GHz, place considerably more emphasis on the attenuation caused by cloud and gas since this is important for systems operating with small fade margins. A video cloud camera and an instrument to measure the height of the cloud base have been regularly employed in conjunction with the beacon receivers and meteorological equipment. A multi-parameter radar has been used to derive concurrent information on the atmospheric constituents for selected periods.