Description of Alphasat TDP5 Propagation Experiment

The paper presents a new satellite-based propagation experiment in the ka and Q bands, planned to start in the 2012, foreseeing the collection of simultaneous attenuation and depolarisation measurements during a 3-years period in Italy and in many locations in Europe. This experiment is a part of a larger projct called Alphasat/TDP#5 that foresees two different activities, one devoted to propagation and a second one to wideband telcommunications; the present paper is limited to describe the propagation one whose baseline design foresees a transmit-only payload radiating two beacon signals at about 20 (ka-band) and 40 GHz (Q-band) from a geostationary platform; the coverage area will be the continental Europe and the North Africa; the polarization of the Q-band beacon will be circular and the reception shall be possible with antennas with diameter of the order of one meter. One of the Earth terminals will be located in the station of Spino d' Adda (about 20 kms from Milano) where also the coordination Centre for the propagation experiment is foreseen; other two terminals will be placed in the area around Roma; moreover, in order to enlarge the significance of this experiment, the development of one or a few prototypes of a propagation ground terminals has been carried out by the ESA with the aim of fostering the involvement of as many European experimenters as possible.