Alphasat Aldo Paraboni,an advanced Q/V band mission space segment

This paper provides an overview of the space segment of the Aldo Paraboni mission on the Alphasat satellite and the technology programme that has developed one of the most powerful geostationary satellites in Europe. The Aldo Paraboni technology demonstration payload, funded by ASI under European Space Agency's Advanced Research in Telecommunications System Programme, was embarked as a hosted payload on the Alphasat satellite, launched on 25 July 2013. The Aldo Paraboni payload is composed of two main elements, an experimental communication payload operating at Q/V bands (COMEX) and a scientific payload formed by 2 beacons at Ka and Q bands (SCIEX). The Aldo Paraboni payload is a key technology element of the Aldo Paraboni Mission, which covers two main objectives: the communication segment of the mission aims at assessing the performance of satellite communication links at Q/V bands and investigating use Fade Mitigation Techniques (FMT, eg, Adaptive Coding and Modulation defined in DVB‐S2 standard), while the scientific segment aims at characterizing in time, space, and frequency the K and Q band radio channel over Europe to permit development and improvement of propagation channels for slant paths.     

Assessment of spatial and temporal properties of Ka/Q band earth‐space radio channel across Europe using Alphasat Aldo Paraboni payload

The upcoming migration of satellite services to higher bands, namely, the Ka‐ and Q/V‐bands, offers many advantages in terms of bandwidth and system capacity. However, it poses challenges as propagation effects introduced by the various atmospheric phenomena are particularly pronounced in these bands and can become a serious constraint in terms of system reliability and performance. This paper presents the goals, organisation, and preliminary results of an ongoing large‐scale European coordinated propagation campaign using the Alphasat Aldo Paraboni Ka/Q band signal payload on satellite, performed by a wide scientific consortium in the framework of a European Space Agency (ESA) project. The main objective of this activity is the experimental characterisation of the spatial and temporal correlation over Europe of the radio channel at Ka and Q band for future modelling activities and to collect data for development and testing of fading mitigation techniques.     

The Alphasat Aldo Paraboni propagation experiment: Measurement campaign at the Italian ground stations

Terabit capacity and very high data rates are required for the near‐future broadband satellite communication systems, mainly for multimedia services. The increased capacity can be obtained by using the larger bandwidth available at higher frequency bands, like Ka and Q/V. However, severe detrimental atmospheric effects impair radio waves at these bands, which require the extensive use of fade mitigation techniques, such as link power control, site diversity, or on‐board adaptive power allocation. The Alphasat Aldo Paraboni propagation experiment was designed and supported by the Italian Space Agency, and implemented by the European Space Agency, to better characterize the atmospheric propagation channel at Ka band and Q band, to support the design of future satellite systems. In Italy, 3 ground stations have been installed and are acquiring the Alphasat beacon signals: the 2 ASI main ground stations in Tito Scalo (Southern Italy) and Spino d'Adda (Northern Italy) and the La Sapienza‐FUB station in Roma (Central Italy). The 3 stations cover quite distant locations in Italy, with different climatic characteristics. This paper describes the main features of the experimental setup in the above stations and presents some examples of measurements and results.     

The Alphasat Aldo Paraboni scientific and communication experiments at Ka and Q/V bands in Austria

The use of higher frequencies for satellite multimedia communication systems calls for research of the atmospheric propagation effects at these bands (rain, cloud and gaseous attenuation, scintillation, and depolarization). Alphasat was successfully launched on 25 July 2013. This largest and most powerful European telecommunication satellite carries, besides a commercial payload belonging to the mobile satellite communication provider Inmarsat, several Technology Demonstration Payloads (TDPs) from ESA. One of them is the Aldo Paraboni payload (TDP5) for Q/V‐band communication and Ka/Q‐band propagation experiments. These experiments explore future applications in satellite communication and measure how the Earth's atmosphere affects the propagation of electromagnetic waves. Under ESA contract, JOANNEUM RESEARCH designed, developed, and operates a Q/V‐band communication ground station and a Ka/Q‐band propagation terminal. The experimental site is equipped with ancillary equipment including a multifrequency radiometer profiler, a 2D video disdrometer (2DVD), and meteorological stations. This paper reports on the experimental setup, data processing, and obtained results.     

The role of the Italian Space Agency in investigating high frequencies for satellite communications: The Alphasat experiment

Since the 1970s, satellite communications have been continuously evolving and improving to provide services characterized by increasing complexity and quality. This evolution has been supported by the constant increase in the operating frequency for achieving the necessary high data rates. This contribution focuses on the long‐term key role of the Italian Space Agency in supporting research activities on (and the developments of) high‐frequency satellite communication systems. The Alphasat experiment is the most recent effort of the Italian Space Agency, in collaboration with the European Space Agency, to thoroughly investigate the severe detrimental atmospheric effects impairing radio waves at high frequency (specifically, Ka and Q bands) and the associated fade mitigation techniques (eg, uplink power control, site diversity, and adaptive coding and modulation) required to achieve the typical target quality and availability of modern satellite communication systems.     

Three‐year fade and inter‐fade duration statistics from the Q‐band Alphasat propagation experiment in Madrid

Propagation campaigns are carried out at different frequencies and geographical areas to characterize the slant‐path propagation channel. One of the objectives of the Alphasat Propagation Experiment is to evaluate the performance of satellite links that operate in the Q/V band. Since March 2014, the copolar level of the Alphasat Q‐band beacon signal has been measured at Universidad Politécnica de Madrid, Spain. The fade dynamics—fade and inter‐fade durations—results for three complete years (March 2014 to February 2017) of measurements are presented in this paper. Moreover, the experimental setup and receiver characteristics are described in detail. The collected data (with a mean availability of 97%) can be used to evaluate the atmospheric propagation impairments with a very good degree of accuracy. The probability of occurrence and the fraction of time of fade duration for an average‐year have been compared with the ITU‐R and CRC models with moderate agreement. For this reason, a modeling effort has been made leading to the conclusion that there is room for improvement in the models.     

NASA's alphasat propagation terminals: Milan,Italy, and Edinburgh,Scotland

Since May of 2014, NASA's Glenn Research Center has operated measurement campaigns for the Alphasat Aldo Paraboni Propagation Experiment alongside the European community of propagation experimenters. Presently, three NASA stations have been deployed to distinct climatological regions across Europe. NASA's participation in the campaign began in 2014 through a collaborative effort with the Politecnico di Milano (POLIMI) to jointly operate a 20/40 GHz ground terminal at the POLIMI campus in Milan, Italy. Subsequently, a single‐channel 40 GHz terminal was deployed to Edinburgh, Scotland in March 2016 in collaboration with Heriot‐Watt University (HWU). A third terminal was deployed to NASA's Madrid Deep Space Communications Complex (MDSCC) in March 2017 with NASA'S Jet Propulsion Laboratory (JPL), also observing the 40 GHz beacon. In addition, a fourth station is planned for deployment to Andøya, Norway by early 2019 in collaboration with the Norwegian Defence Research Establishment (FFI). This paper will detail the design and results of the two most established terminals, Milan and Edinburgh, which together comprise 11 station years of propagation measurements.