The formulation of a wave propagation model through a turbulent ionosphere is presented. The calculation of the transmitted field enables the estimation of signal impairments, especially its intensity and phase fluctuations. The model outputs are compared with measurement results. This was performed for the intensity and phase fluctuation levels and for the spectral content of the transmitted signal. The field second-order moment calculation is then presented. The mutual coherence function characterizes the channel transfer function. It is required for radar performances assessment after propagation through the turbulent medium. It was demonstrated that under simplified hypothesis, an analytical solution can be derived allowing a sensitivity analysis study.
Abstract. The ESA MONITOR network is composed of high-frequency-sampling global navigation satellite systems (GNSS) receivers deployed mainly at low and high latitudes to study ionosphere variability and jointly with global GNSS data and ionospheric processing software in support of the GNSS and its satellite-based augmentation systems (SBAS) like the European EGNOS. In a recent phase of the project, the network was merged with the CNES/ASECNA network and new receivers were added to complement the latter in the western African sector. This paper summarizes MONITOR, presenting two case studies on scintillations (using almost 2 years of data measurements). The first case occurred during the major St. Patrick's Day geomagnetic storm in 2015. The second case study was performed in the last phase of the project, which was supported by ESA EGNOS Project Office, when we paid special attention to extreme events that might degrade the system performance of the European EG-NOS.
Full Paper -Radiating element optimization is a key factor to improve the overall performances of an array antenna: its type and design must meet RF specifications while being competitive in terms of cost, bulkiness and weight. This paper focuses on the design, manufacturing and test of a splineprofile square horn, designed to be used for telecommunication focal array applications with high efficiency requirements
This paper presents an ionosphere scintillation mapping algorithm. The technique used is a Kriging technique, well known in geostatistics. It is an interpolation method applied to a set of random data, namely, in this application, to the intensity scintillation (S4) index. The paper focuses on the importance of the regression model used in the algorithm. The one-dimensional and then the two-dimensional problems have been investigated. One example of results combining measurement data recorded by two different networks in Peru is presented. The accuracy of the results has been verified using a cross-validation technique, which consists in removing part of the known data set and comparing the interpolated results to it.
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