A novel scheme is described for determining the position of an unknown mobile terminal without any prior information of transmitted signals, keeping in mind, for example, radiowave surveillance. The proposed positioning algorithm is performed by using a single base station with an array of sensors in multipath environments. It works by combining the spatial characteristics estimated from data m...

We present new results on the resolution of singular transmission problems in Hölder spaces completing in this way the work in L cases given in [A. Favini, R. Labbas, K. Lemrabet, S. Maingot, Study of the limit of transmission problems in a thin layer by the sum theory of linear operators, Rev. Mater. Comput. 18 (1) (2005) 143–176]. Our approach makes use of the impedance notion operator [M.A. ...

Solar flares increase the electron number concentration in daytime ionosphere, potentially affecting radiowave propagation over several frequency ranges. In this study, we use ionospheric observations to determine both peak magnitudes and time variations of solar flare X-rays without using direct measurement from flare. Ground-based VLF transmitter phase perturbations are compared against measu...

Investigations in this paper focus on establishing the uniqueness properties of Quasi-Moment-Method (QMM) solution to problem calibrating nominal radiowave propagation pathloss prediction models. Nominal (basic) models utilized for investigations, were first subjected QMM calibrations with measurements from three different scenarios. Then, recast forms suitable Singular Value Decomposition (SVD...

Little is known about radiofrequency electromagnetic fields (RF) from mobile technology and resulting dose in young people. We describe modeled integrated RF European children adolescents combining own device use surrounding sources. Using an model, we estimated the daily brain (whole-brain, cerebellum, frontal lobe, midbrain, occipital parietal temporal lobes) whole-body 8358 (ages 8–12) 14–18...

Modelling radio wave propagation through vegetation is becoming increasingly more important. Many emperical solutions have been suggested in the past. The theory of radiative energy transfer offers an analytical method to the problem. This theory requires however 4 imput paramters, which need to be established experimentally. A measurement of the angular scatter pattern, the so called ‘phase fu...

The International Reference Ionosphere (IRI) a joint project of URSI and COSPAR is the defacto standard for a climatological specification of ionospheric parameters. IRI is based on a wide range of ground and space data and has been steadily improved since its inception in 1969 with the ever-increasing volume of ionospheric data and with better mathematical descriptions of the observed global a...

Considering Rayleigh fading channels, in this work we adopt channel inversion power control to achieve covert communications, where a transmitter can possibly hide itself from a warden while transmitting information to a receiver. Specifically, we examine the performance of the achieved covert communications in two scenarios in terms of the effective covert rate (ECR), which quantifies the amou...

Microwave remote sensing techniques are used, among others, for temporally and spatially highly-resolved observations of land-surface properties, e.g., for the management of agricultural productivity and water resource, as well as to improve the performances of numerical weather prediction and climate simulations with soil moisture data. In this context, the effective dielectric constant of the...