PLATON: Satellite Remote Sensing, Navigation and Telecommunication by using Millimetre Waves

Nowadays, climate and meteorology assumed a fundamental role in manifold domains with the aim to understand how they affect life in modern society. Such a new sensitivity is the result of a major awareness of the Earth health and the need of better understanding the increasing climatic and meteorological changes recently observed. Actually, in the last years several satellite missions, single and cooperative, have been proposed and realised by NASA, ESA and JAXA. They aim at studying the overall atmosphere, its main elements and their close relations. On the other hand, in a different domain such as telecommunications, the low frequency bands crowding and the increase of broadband services diffusion has created the premises for the development of studies on the characterisation and the development of telecommunications in the millimetric band not yet explored for this purpose (Q-V bands-35-75 GHz, W band-75-110 GHz). Actually, nowadays satellite telecommunications at Ka band can be considered a standard for broadband services. Higher frequencies such as Q-V bands are currently employed for military applications (SICRAL satellite of the Italian Defence Ministry) and soon for scientific applications (TDP#5 payload on-board the ESA Alphabus platform [1]). W band can be considered as the most important scientific frontier within the broadband satellite communications, since no satellite system operating at such a frequency has been developed, just studies such as DAVID and WAVE [2][3][4]. In the last years these fields registered a convergence of research activities towards the use of electromagnetic radiation at millimetre wavelengths, i.e. the EHF band (Extremely High Frequency, 30-300 GHz). In telecommunications the use of carriers at higher frequency implies theoretically the possibility of using wide bandwidth and hence greater data rate in down link. In the field of weather and climate satellite observations, the technology advancements of the last 10 years make available several sensors (radar, lidar, radiometers, etc.) in the 30-300 GHz band. They allow, by means of observations unpredictable some years ago, for broadening the knowledge of meteorological and climatological phenomena and the improvement of predictive models. However, the capability of collecting large data volumes leads to a related capability of transmitting the data to ground within reduced visibility windows. An integrated TeLeCommunication-Earth Observation approach (TLC-EO) could satisfy both needs. ARES (Advanced Research and Engineering for Space), a consortium constituted both by scientific institutions (the University of Rome Tor Vergata) and industrial partners (Rheinmetall Italy and TECS, TEchnological Consulting Services) carried out a feasibility study to investigate an innovative satellite devoted both to Earth remote sensing and to high frequency telecommunications. Both payloads are based on the common use of millimetric band to exploit the favourable characteristics of such high frequencies. The study is called PLATON (PayLoad for Advanced Telecommunication, Observation and Navigation) [5].