A5055249122- Precipitation Measurement and Analysis
- Radio Wave Propagation Studies
- Satellite Communication Systems
- Meteorological Phenomena and Simulations
- Atmospheric aerosols and clouds
- Soil Moisture and Remote Sensing
- GNSS positioning and interference
- Millimeter-Wave Propagation and Modeling
- Radio Astronomy Observations and Technology
- Ionosphere and magnetosphere dynamics
- Geophysics and Gravity Measurements
- Wireless Communication Networks Research
- Advanced Wireless Communication Techniques
- Telecommunications and Broadcasting Technologies
- Spacecraft Design and Technology
- Advanced MIMO Systems Optimization
- Climate variability and models
- Photonic and Optical Devices
- Power Line Communications and Noise
- Semiconductor Lasers and Optical Devices
- Antenna Design and Optimization
- Optical Network Technologies
- Spacecraft and Cryogenic Technologies
- Astro and Planetary Science
- Atmospheric Ozone and Climate
European Space Research and Technology Centre
2015-2024
European Space Agency
2009-2021
Agenzia Spaziale Italiana
2016
Centro de Estudos e Pesquisa em Saúde Coletiva
2011
Fondazione "Ugo Bordoni"
1988-2002
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> An improved version of the exponential cell (EXCELL) rain attenuation model is presented here. Analogously to original one, it predicts through a cellular representation precipitation, but, in addition, able discriminate between stratiform and convective by means an embedded algorithm. Accordingly, two separate physical heights, derived from ERA-15 database, are used calculate and, when...
SUMMARY This contribution outlines the scenario of expected atmospheric impairments, which affect a satellite radio link operating in W band, as derived by present theoretical and experimental knowledge. The paper discusses contributions to signal fade due gases, clouds, scintillation rain (with emphasis also on impact hydrometeor size distribution), well depolarization electromagnetic waves. main objective is assess constraints face design telecommunication system band. Copyright © 2013...
A large database of radio-soundings, brightness temperatures, and satellite beacon data was used to verify the ability radiometers in estimating attenuation nonprecipitating conditions at millimeter wavelengths. The mass absorption models proposed by Liebe Rosenkranz have been coupled with Helsinki University Technology (TKK) cloud-detection model derive coefficients for calculation due integrated water vapor liquid contents. Comparison predicted measured cumulative distribution functions...
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The control of the radiation a telecommunication multispot satellite antenna is discussed in which power can be flexibly routed towards various spots so as to contrast at best time variant atmospheric attenuation while keeping minimum number users do not receive enough signal level. exerted by applying particular strategy based on knowledge distribution weather conditions all over served region...
After a review of the physical/mathematical definitions anisotropy and canting angle, parameters currently used for describing depolarization electromagnetic waves due to hydrometeors, we present some specific algorithms retrieve these from measurements atmospheric polarization transfer matrix, based on data collected during Italsat propagation experiment at 50 GHz in slant path with elevation angle 37.7 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Abstract Media propagation delay and delay‐rate induced by the water vapor within Earth's troposphere represent one of main error sources for radiometric measurements in deep space. In preparation BepiColombo JUICE missions, European Space Agency has installed operates prototype a tropospheric calibration system (TDCS) at DSA‐3 ground station located Malargüe, Argentina. An initial characterization TDCS performance was realized using two‐way Doppler X‐band to perform orbit determination Gaia...
Abstract The aim of this paper is to present recent developments in terms propagation time‐series synthesizers, carried out the framework ESA study 16865/03/NL/EC ‘Development models for telecommunication satellite systems’ ( ONERA Final Report RF 4/07757/DEMR , 2004). composed three parts: a review initial requirements related time series system performance simulation, description collection rain attenuation synthesizers and their input parameters, comparative analysis output...
A physically-based parametric model (PPM) to predict the sky-noise temperature in all weather conditions is proposed. The proposed prediction based on non-linear regression fit of numerical simulations derived from eddington radiative-transfer (SNEM) an absorbing and scattering medium such as gaseous, cloudy rainy atmosphere. PPM method, dependent measured path attenuation, beacon frequency, antenna-pointing elevation angle, describes statistical behavior atmospheric mean radiative...
Summary The upcoming migration of satellite services to higher bands, namely, the Ka‐ and Q/V‐bands, offers many advantages in terms bandwidth system capacity. However, it poses challenges as propagation effects introduced by various atmospheric phenomena are particularly pronounced these bands can become a serious constraint reliability performance. This paper presents goals, organisation, preliminary results an ongoing large‐scale European coordinated campaign using Alphasat Aldo Paraboni...
Inversion algorithms for ground-based microwave radiometric retrieval of surface rain-rate, integrated cloud parameters, and slant-path attenuation are proposed tested. The estimation methods trained by numerical simulations a radiative transfer model applied to microphysically-consistent precipitating structures, representative stratiform convective rainy clouds. discrete-ordinate method is used solve the equation plane-parallel seven-layer including liquid, melted, ice spherical...
State-of-the art downlink technology allows Low Earth Orbit (LEO) satellites for observation (EO) to just above 500 Mb/s in the X-band due bandwidth limitations. is also becoming very congested. The ITU allocates four times more 26 GHz band (i.e. 25.5 27 GHz) EO downlink. This particularly challenging terms of atmospheric propagation effects. Data (DDL) system studies, characterization studies and pre-development are on-going Europe USA. paper addresses main architecture related technical...
This paper describes a methodology to model the propagation conditions for Earth observation data downlink operating at Ka band. It relies on use of numerical weather forecast models perform local high resolution reanalysis meteorological which effects can be computed. From simulations spanning long durations, time series representative attenuation between an orbiting satellite and ground station are extracted, knowing orbital RF characteristics system.
The paper summarizes the baselines of a new satellite payload for radiowave propagation measurements in Ka and Q/V bands which is being developed by European Space Agency ESA Alphasat mission with full support Italian (ASI). experiment will be based on geostationary allow collecting set multiple simultaneous attenuation depolarization during period at least 3 years (with possible extension up to 5 years) many locations spread across large area. This represents natural continuation commitment...
Satellite communication systems operating at high frequencies (Ka-band and above) are severely impaired by atmospheric phenomena, particularly in tropical equatorial regions, where the climatic characteristics affect several propagation parameters, including rain, cloud gaseous attenuation, fade duration, slope, sky noise emission site diversity gain.
Atmospheric refractivity and its vertical gradient affect electromagnetic wave propagation in the atmosphere. Consequently, their statistics are needed for predictions. New world maps of derived from a global, long-term dataset meteorological quantities as given by ERA-Interim reanalysis. The provide obtained 33 years data with one-degree spatial resolution on latitude/longitude mesh. A processing method is described examples shown. consistency new checked comparing provided ITU-R. Accuracy...
A procedure to extract rain attenuation from MEO satellite signals is presented in the framework of MEKaP (MEO Ka-band Propagation), a European Space Agency (ESA) funded project. This task involves removing received signal effects induced by presence gases along path, change distance and variation onboard antenna gain as perceived at ground station. To this aim, ancillary data are exploited, such ephemeris, ERA5 products some basic information on antenna. Some preliminary examples derived...
Radiometric measurements could provide continuous information about atmospheric conditions. In this paper, a sky status indicator (SSI) is proposed as real-time recognition criterion for the detection, in particular, of presence rain events along propagation path. The computation SSI based on ground-based brightness temperature measurements, at 23.8 and 31.4 GHz, collected Cabauw, Netherlands, 2009 by ESA Atmospheric Propagation Profiling System (ATPROP) multichannel radiometer. A validation...
The Alphasat satellite was launched on 25 July 2013. Aldo Paraboni technology demonstration payload, funded by ASI under ESA's ARTES Programme, embarked as an hosted payload Alphasat. This Technology Demonstration Payload (identified TDP5 and recently renamed "Aldo Paraboni") implemented ESA contract awarded in co-contractorship to Space Engineering Thales Alenia Italia (TAS-I) which conceived the experimental mission industrialised subsystems. is composed of two main elements: a...
In this paper the authors present results of a study aiming at detecting rainy data in measurements collected by dual band ground-based radiometer.The proposed criterion is based on ratio brightness temperatures observed 20–30 GHz without need any ancillary information. A major result obtained from probability density computed over one month identification threshold values between clear sky, cloudy sky and respectively. linear fit performed using radiometric concurrent rain gauge shows...
Tropospheric scintillation effect is well modelled for Earth to satellite communication in clear air conditions. Statistical models are available geostationary and non-geostationary satellites. Time series simulators have been developed links not valid spatial applications involving LEO satellites such as Observation Satellites. A new model proposed order take into account both the dynamic behaviour of troposphere movement satellite. This takes advantages outputs generated by Weather...
In this work, we propose a model for the probability density function (pdf) of elevation angle and pdf attenuation conditioned to at W-band in all weather conditions. The proposed models are suitable retrieve total variable application non-geostationary (NGEO) satellite communication (SatCom) links W-band. models, based on generalized extreme value (GEV) distribution, were developed tested exploiting Sun-tracking (ST) microwave radiometer (MWR) measurements available from two independent...
In order to study propagation effects for future satellite communication frequencies, the Alphasat Aldo Paraboni payload includes two beacon transmitters at Ka-band (19.701 GHz) and Q-band (39.402 GHz). Among all atmospheric effects, rain has biggest impact on signal transmission. Often a single statistical relationship (derived from climatic parameters) between rate specific attenuation is used, but it well known that variability of drop size distribution (DSD) given considerably large...
Abstract Media propagation noises are amongst the main error sources of radiometric observables for deep space missions, with fluctuations tropospheric excess path length representing a relevant contributor to Doppler noise budget. Microwave radiometers currently represent most accurate instruments estimation delay and rate along slant direction. A prototype calibration system (TDCS), using 14 channel K /V band microwave radiometer, has been developed under European Space Agency contract...