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Presents the introductory welcome message from the conference proceedings. May include the conference officers' congratulations to all involved with the conference event and publication of the proceedings record.
Universidad Politécnica de Madrid (UPM) is participating in the Alphasat propagation experiment by measuring the copolar level of the Q-Band beacon at 39.4 GHz since April 2014. In this paper the results of the first two complete years of measurements (until March 2016) are presented with regards to excess and total attenuation. The reference level is calculated on an event-by-event basis in the first...
A heuristic algorithm based on two threshold values of a scalar indicator, given by the ratio of the brightness temperatures measured by a ground-based radiometer at 31.4 and 23.8 GHz, is employed to detect the presence, if any, of rain events along the Earth to satellite propagation path in the framework of the Alphasat Aldo Paraboni Propagation Experiment. The promising preliminary results have...
In this paper, the differential total atmospheric attenuation and differential total losses are investigated in the case of spectral co-existence of GEO and MEO constellation satellite communication systems. In order to use larger bandwidth in the next generation satellite communication systems, many radio systems may share the same spectrum. Due to the high interest on MEO constellation systems to...
Scintillations affect the propagated signal with an unwanted aleatory oscillation at the receiver. A first analysis of data acquired from Alphasat Q-band receiver station, located in Spino d'Adda (Italy), is performed. Correlation between meteorological measurements at the ground and measured scintillation from the Q-band beacon receiver (i.e., fluctuation of the received electromagnetic field) is...
The performance of both a recent rainfall rate model and the inter-annual variability prediction method proposed by the International Telecommunication Union has been assessed taking advantage of the availability of 16 years of rain gauge data. The above rainfall rate model produces as well monthly rainfall rate distributions that have been compared with the experimental monthly distributions achieving...
Simultaneous measurements of tropospheric scintillation on three different satellite beacons at Ka-band are analyzed. The links have elevation angles of 3.3, 21.8 and 22 degrees. Corner frequency of scintillation is used to calculate the transverse wind speed on each of the links and this is compared with the predictions from a numerical weather model. Results for the two links with higher elevation...
Physical-based rain attenuation prediction models conventionally assume a deterministic dependence of rain cell size on rainfall rate and uniaxial structure. This study examined the impact of these assumptions on attenuation predictions. In comparison with model predictions that apply an exponential distribution of cell sizes, the deterministic models exhibited a small cell size effect in which the...
Drop Size Distributions (DSDs) measured with an optical disdrometer in Madrid during 5 years are used to derive the copolar attenuation (CPA) and cross polarization discrimination (XPD) at 19.7 and 39.4 GHz. A full wave Method of Moments (MoM) is utilized to calculate specific attenuation and phase rotation through a realistic scattering raindrop model for large raindrops. The best-fit parameters...
The move towards higher frequency bands like 26GHz or 32GHz for scientific satellite data downlinks calls for the need to better characterise the atmosphere at the sites where ground antennas are located. For this reason ESA is undertaking the deployment of microwave radiometers at its Deep Space station locations. This paper reports the results of the first two years of site characterisation at the...
For the last decades satellite communication systems have been moving towards higher and higher frequencies; rain attenuation along the Earth-satellite path can be an important limiting factor for the system availability, especially in tropical regions where rain events can be particularly intense. One of the possible countermeasures is site diversity. In this paper we evaluate the performance of...
The employment of optical frequencies in satellite communication systems has been proposed in order to cover the huge needs for capacity in the next decade. The reliable design and the prediction of the performance of optical satellite links need accurate channel modeling in the form of time series generators. Considering cloud free line-of-sight (CFLOS) satellite links, turbulence effects on the...
The objective of this paper is to present the development of a new software tool for the analysis of propagation effects on satellite-to-aircraft communications, valid for frequencies between VHF and Ka-band. This tool shall take into account several phenomena that influence the characteristics of the propagation channel, and therefore the performances of the link. First of all, the antenna pattern...
Transmitarray antennas with dual-band and dual-polarization capabilities are studied here numerically. The antennas are designed based on linearly-polarized unit-cells working at Ka-band for satellite applications. The unit-cells include two printed patches and a connecting via; a 180° phase shift is obtained by rotating one of the patches. The dual-band property is achieved by interleaving unit-cells...
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