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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Long-Term and Short-Term Atmospheric Impairments Forecasting for High Throughput Satellite Communication Systems
摘要： In this paper, three different methodologies are employed for the prediction of atmospheric attenuation for the performance evaluation of High Throughput Satellite Communication systems. The first one is based on numerical weather predictions and in particular the ECMWF forecasts that uses high resolution deterministic forecast and the probabilistic forecasts the perturbated products. The second methodology is based machine learning algorithms, which are advanced statistical methods. The two algorithms tested in this study are the random forest and the gradient boosting, both based on regression trees. Finally, the last method that is employed is the recurrent neural networks and in particular the Long Short Term Memory. These neural networks are used for the prediction of time series using memory blocks. All the algorithms are tested using data from the ALPHASAT experiment at Chilbolton and Chilton, UK. The obtained results are very encouraging.
关键词： radiowave propagation,forecast,Ka band and above,Satellite Communications,deep learning,machine learning
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Numerical Weather Prediction Models for the Estimate of Clear-Sky Attenuation Level in Alphasat Beacon Measurement
摘要： With the move of satellite systems towards Ka and QIV bands, the Alphasat TDPS Aldo Paraboni scientific experiment aims to characterize atmospheric attenuation in those bands. However, during the retrieval of the attenuation from the measured beacon signal, the clear-sky contribution to attenuation is lost. Microwave radiometers give the clear sky absolute reference level, but these are costly and not always available. This paper proposes Numerical Weather Prediction models as an alternative source of clear-sky attenuation. Three months of beacon and radiometric data from Spino d' Adda the Alphasat receiving station are used as benchmark for validation of the method. A preliminary conclusion is that gaseous attenuation is well predicted, but cloud attenuation is underestimated.
关键词： microwave radiometer,Numerical Weather Prediction model,radiowave propagation,clear-sky attenuation,Alphasat
更新于2025-09-04 15:30:14
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Input-to-Output Instantaneous Polarization Characterization
摘要： This paper proposes a method to represent and predict received signal instantaneous polarization states as a function of arbitrary transmit polarization states for time-dispersive channels. The model incorporates frequency-dependent characterizations to represent the polarization dispersion behavior of a received signal across its bandwidth in a multipath channel. The representation takes advantage of signal dispersion features typical of depolarized signals, and employs subbanded characterizations to achieve polarization representations exhibiting high degrees of polarization in each subband. Experiments are conducted that demonstrate the utility of the modeling approach to predict polarization dispersion responses for arbitrary transmit polarizations based on measurements from two orthogonal transmit polarizations.
关键词： radiowave propagation,Stokes parameters,polarization estimation,dispersion
更新于2025-09-04 15:30:14