Attenuation Characteristics at 20-GHz from Long-Term Slant-Path Measurements at Three Sites
Amaya, C. A
; Riera, J. M. R.
Attenuation Characteristics at 20-GHz from Long-Term Slant-Path Measurements at Three Sites, Proc COST-Propagation Tools and Data for Integrated Telecommunication, Navigation and Earth Observation Systems COST IC0802 , Erice, Italy, Vol. 1, pp. 1 - 1, November, 2010.
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Satellite communication systems operating in the Ka-band and above are expected to experience a significant growth in the next few years, with the launch of new satellites such as the Ka-sat satellite in Europe, ViaSat-1 in the USA and Yahsat in the Middle East. In this band, propagation effects such as rain attenuation or the influence of gases and clouds cause deeper fades than at lower frequencies. Communication systems provide means to mitigate such propagation impairments, but a better experimental characterization of propagation effects can lead to better design and operation of fade mitigation techniques (FMT).
Several propagation experiments in the Ka-band were carried out in the past with the Olympus and Italsat satellites in Europe and with the ACTS in the USA and Canada. Currently, long-term propagation campaigns are being carried out in Ottawa, Canada (satellite Anik F2), Aveiro, Portugal and Madrid, Spain (satellite HotBird 6 in both cases). The measurements started in 2004 in Aveiro and in 2006 in Ottawa and Madrid, and have been running on since then with only short service interruptions. Thus, a large database is available in each site, with registered data corresponding to 4-6 years.
In this collaborative paper, each one of the three experiments is briefly presented. Then, the main results corresponding to rain attenuation at each site are discussed. Cumulative distributions of rain attenuation at each site are presented for several years, so that the year-to-year variability can be shown, as well as the differences between the links, arising from the different climates and elevation angles.
Additional results are included regarding fade dynamics or hourly/seasonal variability. However, the paper is focused on the need of carrying out experiments lasting several years, the type of equipment needed and the results that can be achieved from these long-term experiments.