ALBERT

Description: The main objective of the ESA ARTES 5.1 Contract 20887/07/NL/LvH “Verification of Propagation Impairment Mitigation Techniques” with Politecnico di Milano as Prime, ONERA and Space Engineering as subcontractors, was to validate the channel models and related input data appropriate for the design, analysis and/or control phase of Propagation Impairments Mitigation Techniques (PIMTs), both for the Broadcasting Satellite Service (BSS) and the Interactive Multimedia Broadband Service (IMMBS). For the BSS scenario, which is the focus of this paper, the On Board Antenna Pattern Reconfiguration (OBAPR) PIMT is investigated, using as channel models the rain field generators able to provide the spatial distribution of rain across the service area on the basis of large-scale meteorological forecasts. Their performance were tested using either radar data or a large dataset of beacon measurements collected in Europe during the OLYMPUS experiment. Content Type Journal Article Pages 71-79 DOI 10.3233/SC-130003 Authors C. Capsoni, Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milan, Italy L. Castanet, ONERA, The French Aerospace Lab, France P. Gabellini, Space Engineering S.p.A., Rome, Italy A. Martellucci, European Space Agency, Noordwijk, The Netherlands G. Carrie, ONERA, The French Aerospace Lab, France G. Gallinaro, Space Engineering S.p.A., Rome, Italy N. Gatti, Space Engineering S.p.A., Rome, Italy N. Jeannin, ONERA, The French Aerospace Lab, France M. Luccini, Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milan, Italy L. Luini, Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milan, Italy R. Nebuloni, IEIIT-CNR, Milan, Italy A. Paraboni, Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milan, Italy L. Resteghini, Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milan, Italy C. Riva, Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milan, Italy Journal Space Communications Online ISSN 1875-9211 Print ISSN 0924-8625 Journal Volume Volume 22 Journal Issue Volume 22, Number 2-4 / 2013

Description: To insure a favourable link budget in order to reach the required availabilities and to counteract severe propagation impairments, Fade Mitigation Techniques (FMT, such as adaptive coding [8, 9]) have to be implemented in the fixed satellites telecommunications systems. To develop, test and adjust the real-time algorithms of these adaptative FMTs, a good knowledge of the dynamics of the propagation channel is required and realistic attenuation time series are needed to feed system simulators. Unfortunately, the low number of available propagation experiments at Ka-band and above unavoidably leads to the use of channel models allowing synthetic total attenuation time series to be generated. The aim of this paper is first of all to present the justification of the parameterization used in Recommendation ITU-R P.1853–1 which has not been published in the open literature. Secondly, some limitations are highlighted before moving on an overview of a more simplified new channel model to synthesize total attenuation time series. Content Type Journal Article Pages 59-70 DOI 10.3233/SC-130002 Authors X. Boulanger, ONERA - ElectroMagnetics & Radar Department, France G. Carrie, ONERA - ElectroMagnetics & Radar Department, France L. Castanet, ONERA - ElectroMagnetics & Radar Department, France L. Feral, LAPLACE - GRE, Université Paul Sabatier, Toulouse, France Journal Space Communications Online ISSN 1875-9211 Print ISSN 0924-8625 Journal Volume Volume 22 Journal Issue Volume 22, Number 2-4 / 2013

Description: Microwaves propagation modelling in clear air troposphere (i.e. without rain) is investigated. Large scale variations of refractivity are computed from mesoscale meteorological modelling. Small scale variations are deduced from large scale considering that the inertial regime of Kolmogorov spectrum is established. The propagation effects are estimated applying launching ray to take into account large scale refractivity effects and resolution of Parabolic Wave Equation with Multiple Phase Screen technique for small scale. The proposed approach has been evaluated versus earth satellite measurements of log-amplitude scintillation measured at Louvain-la-Neuve. Content Type Journal Article Pages 51-57 DOI 10.3233/SC-130001 Authors V. Fabbro, ONERA, Toulouse, France N. Jeannin, ONERA, Toulouse, France K. Djafri, UCL, ICTEAM, Bâtiment Maxwell, Louvain-la-Neuve, Belgium J. Lemorton, ONERA, Toulouse, France D. Vanhoenacker-Janvier, UCL, ICTEAM, Bâtiment Maxwell, Louvain-la-Neuve, Belgium Journal Space Communications Online ISSN 1875-9211 Print ISSN 0924-8625 Journal Volume Volume 22 Journal Issue Volume 22, Number 2-4 / 2013

Description: The present paper studies, interference issues arising from, the spectral and spatial coexistence between terrestrial stations participating in fixed wireless networks or in a point-to-point link and satellite terminals belonging to a satellite communication network, operating at frequencies above 10 GHz. Rain attenuation is considered to be the dominant fading mechanism at this frequency range. The acceptable intersystem interference probability (AIIP) of the carrier-to-interference ratio (CIR) of a terrestrial station interfered by a satellite is defined and analytically calculated. Adaptive power control schemes are assumed to operate for both networks. The correlated propagation fading phenomena over multiple terrestrial and slant paths are accurately incorporated. The proposed model is physical and can be applied on a global scale since incorporates properly the local climatic conditions concerning the point rainfall rate and the spatial rainfall inhomogeneity. Useful numerical results of the present model are finally provided and the impact of various crucial operational and geometrical parameters of satellite and fixed wireless networks' coexistence is also examined. Content Type Journal Article Pages 205-212 DOI 10.3233/SC-130016 Authors Athanasios D. Panagopoulos, Division of Information Transmission Systems and Materials Technology, School of Electrical and Computer Engineering, National Technical University of Athens, Zografou, Athens, Greece Theodor D. Kritikos, Division of Information Transmission Systems and Materials Technology, School of Electrical and Computer Engineering, National Technical University of Athens, Zografou, Athens, Greece John D. Kanellopoulos, Division of Information Transmission Systems and Materials Technology, School of Electrical and Computer Engineering, National Technical University of Athens, Zografou, Athens, Greece Journal Space Communications Online ISSN 1875-9211 Print ISSN 0924-8625 Journal Volume Volume 22 Journal Issue Volume 22, Number 2-4 / 2013

Description: The provision of multimedia services via a non-geostationary satellite system requires advanced traffic engineering procedures. It includes adaptive routing, adaptive forwarding and appropriate signalling. In this study, we evaluate the impact of different signalling procedures on the performance of a network. The signalling procedures were used in conjunction with traffic class dependent routing, smoothed link-cost functions and adaptive forwarding alleviates the oscillations in the traffic distribution. The performance of the proposed signalling procedures is evaluated in two different traffic load scenarios. The simulation results are presented in terms of the average packet delay in the network and the average normalized data throughput. The simulation results indicate that the proposed triggered signalling significantly decreases the signalling load, while the network's performance is not deteriorated in terms of packet delay and data throughput. Content Type Journal Article Pages 191-203 DOI 10.3233/SC-130015 Authors Ales Svigelj, Jozef Stefan Institute, Jamova, Ljubljana, Slovenia Mihael Mohorcic, Jozef Stefan Institute, Jamova, Ljubljana, Slovenia Laurent Franck, ENST site of Toulouse, Edouard Belin, Toulouse Cedex, France Gorazd Kandus, Jozef Stefan Institute, Jamova, Ljubljana, Slovenia Journal Space Communications Online ISSN 1875-9211 Print ISSN 0924-8625 Journal Volume Volume 22 Journal Issue Volume 22, Number 2-4 / 2013

Description: Introduction to the special issue of Space Communication Journal on the ESA Workshop on radiowave propagation - 2011 Content Type Journal Article Pages 49-50 DOI 10.3233/SC-130014 Authors L. Castanet A. Martellucci R. Prieto-Cerdeira Journal Space Communications Online ISSN 1875-9211 Print ISSN 0924-8625 Journal Volume Volume 22 Journal Issue Volume 22, Number 2-4 / 2013

Description: This paper describes a wave propagator that can be used to simulate radio occultation measurements. The wave propagator is used to simulate a number of radio occultations based on European Centre for Medium-range Weather Forecasts (ECMWF) atmospheric profiles. The output from the wave propagator is used as input to a Full Spectrum Inversion (FSI) retrieval module, which calculates geophysical parameters. These parameters are compared to the ECMWF atmospheric profiles. We also compare the output from the wave propagator with that of a 3D ray tracer. Such comparisons can be used to reveal system errors and get a better understanding of the physics of the problem and the retrieval errors in the inversion of radio occultation measurements. Content Type Journal Article Pages 179-187 DOI 10.3233/SC-130013 Authors Hans-Henrik Benzon, Danish Meteorological Institute, Lyngbyvej, Copenhagen East, Denmark Stig Syndergaard, Danish Meteorological Institute, Lyngbyvej, Copenhagen East, Denmark Journal Space Communications Online ISSN 1875-9211 Print ISSN 0924-8625 Journal Volume Volume 22 Journal Issue Volume 22, Number 2-4 / 2013

Description: The objective of this study, named AWARDS (Advanced microWAve Radiometers in Deep space Stations), is the preliminary design of a transmission Media Calibration System (MCS) to be located at an ESA Deep Space Antenna (DSA) site. The crucial aspect is the capability to accurately retrieve the tropospheric path delay along the line-of-sight of the deep space probe in order to allow precise tropospheric calibration of deep space observables (range and range-rate) with particular reference to the BepiColombo spacecraft and its primary DSA at Cebreros (ES). The study focuses on two main aspects which lead to the preliminary design of the Mercury Orbiter Radioscience Experiment (MORE) MCS: the characterization of current microwave radiometers (MWRs) available at ESA/ESTEC and the atmospheric fluctuation effects on the MCS error budget, in terms of the Allan standard deviation (ASD). In the course of the study, further critical aspects have been identified (effects of Sun contamination, effects of ground noise emission), and mitigation strategies have been proposed. The final outcome is a preliminary design of the MWR (and the entire MCS) to be deployed at the ESA/ESTRACK (ESA Tracking station network) sites and being compliant with MORE requirements. Content Type Journal Article Pages 159-170 DOI 10.3233/SC-130011 Authors Paolo Tortora, Department of Industrial Engineering, University of Bologna, Via Fontanelle, Forlí, Italy Susanne Crewell, Institute of Geophysics and Meteorology, University of Cologne, Cologne, Germany Gunnar Elgered, Department of Earth and Space Sciences, Chalmers University of Technology, Onsala, Sweden Alberto Graziani, Department of Industrial Engineering, University of Bologna, Via Fontanelle, Forlí, Italy Per Jarlemark, SP Technical Research Institute of Sweden, Borås, Sweden Ulrich Loehnert, Institute of Geophysics and Meteorology, University of Cologne, Cologne, Germany Antonio Martellucci, European Space Agency, ESTEC, Noordwijk, The Netherlands Mattia Mercolino, European Space Agency, ESOC, Darmstadt, Germany Thomas Rose, Radiometer Physics GmbH, Meckenheim, Birkenmaarstrasse, Meckenheim, Germany Jan Schween, Institute of Geophysics and Meteorology, University of Cologne, Cologne, Germany Journal Space Communications Online ISSN 1875-9211 Print ISSN 0924-8625 Journal Volume Volume 22 Journal Issue Volume 22, Number 2-4 / 2013

Description: MIMO systems are already state-of-the-art in terrestrial systems. With the availability of satellites with higher EIRP the high spectrum efficiency offered by MIMO systems becomes applicable to satellite-based systems, too. The MIMOSA project covers the evaluation of the satellite MIMO channel characteristics by field measurements. In particular, the estimated capacity increase for mobile reception is evaluated. The measurements have been completed, but the analysis is still ongoing. This paper describes the measurement setup and includes selected results from the statistical analysis. Content Type Journal Article Pages 145-158 DOI 10.3233/SC-130010 Authors E. Eberlein, Fraunhofer IIS, Erlangen, Germany F. Burkhardt, Fraunhofer IIS, Erlangen, Germany G. Sommerkorn, TU Ilmenau, Germany S. Jaeckel, Fraunhofer HHI, Berlin, Germany R. Prieto-Cerdeira, European Space Agency, ESTEC, Noordwijk, The Netherlands Journal Space Communications Online ISSN 1875-9211 Print ISSN 0924-8625 Journal Volume Volume 22 Journal Issue Volume 22, Number 2-4 / 2013

Description: In this paper we present an enhanced version of previous narrowband land mobile satellite, LMS, channel models. Some of the shortcomings of the previous models have been identified and corrections proposed. The model is well suited for generating synthetic time-series. Content Type Journal Article Pages 125-132 DOI 10.3233/SC-130008 Authors F. Pérez-Fontán, University of Vigo, Spain G. Carrie, ONERA, France J. Lemorton, ONERA, France F. Lacostec, CNES, France B. Montenegro-Villacieros, UCL, Belgium D. Vanhoenacker-Janvier, UCL, Belgium Journal Space Communications Online ISSN 1875-9211 Print ISSN 0924-8625 Journal Volume Volume 22 Journal Issue Volume 22, Number 2-4 / 2013