A5006936031- Ionosphere and magnetosphere dynamics
- GNSS positioning and interference
- Earthquake Detection and Analysis
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Soil Moisture and Remote Sensing
- Electromagnetic Scattering and Analysis
- Radio Wave Propagation Studies
- Gyrotron and Vacuum Electronics Research
- Underwater Acoustics Research
- Electromagnetic Compatibility and Measurements
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Solar and Space Plasma Dynamics
- Astrophysics and Cosmic Phenomena
- Geomagnetism and Paleomagnetism Studies
- Photonic and Optical Devices
- Ocean Waves and Remote Sensing
- Seismic Waves and Analysis
- Millimeter-Wave Propagation and Modeling
- Plasma Diagnostics and Applications
- Microwave Engineering and Waveguides
- Geophysics and Sensor Technology
- Antenna Design and Analysis
- Optical Coatings and Gratings
- Image and Signal Denoising Methods
St Petersburg University
2013-2023
Saint Peter's University
2018
Middle East Technical University
2009
University of Leeds
2000-2007
Institute of Physics
1995
A new model for scintillation on transionospheric links, based a hybrid method and valid strong scintillations, has been developed used to construct software channel simulator. The is combination of the complex phase random screen technique. parameters are determined as result rigorous solution problem propagation inside ionosphere using extended Rytov approximation (the method). two‐dimensional spatial spectrum at then transferred down Earth's surface employing relationships theory. Thus...
This paper presents a review of the ionospheric scintillation monitoring and modelling by European groups involved in COST 296. Several these have organized measurement campaigns at low high latitudes. Some characteristic results obtained from measured data are presented. The also addresses modeling activities: four models, based on phase screen techniques, with different options application domains detailed. Finally some new trends for research topics given. includes wavelet analysis,...
Radio wave scintillations are rapid fluctuations in both amplitude and phase of signals propagating through the atmosphere. GPS can be affected by these disturbances which lead to a complete loss lock when electron density strongly fluctuates around background ionization level at small spatial scales. This paper will present recent improvements theoretical Global Ionospheric Scintillation Model (GISM), particularly tailored for satellite based navigation systems such coupled with Satellite...
It can be important to determine the correlation of different frequency signals in L band that have followed transionospheric paths. In future, both GPS and new Galileo satellite system will broadcast three frequencies enabling more advanced correction schemes so knowledge correlations pairs for scintillation conditions is desirable. Even at present, it would helpful know how dual‐frequency Global Navigation Satellite Systems positioning affected by lack between L1 L2 signals. To treat this...
The analytical theory of the Global Navigation Satellite Systems (GNSS) signal propagation through inhomogeneous ionosphere with time-varying embedded localized random inhomogeneities electron density is constructed in order to describe regime strong scintillation wave field propagating ionospheric layer. based on solutions appropriate Markov's parabolic moment equations, extended case background medium. are validated by comparison some rigorous (numerical) known for limiting cases....
The physics-based software simulator of the Global Navigation Satellite System signals on transionospheric paths propagation is presented, which provides possibility for generating field amplitude and phase random time series in conditions strong scintillations, including case when it formed inside inhomogeneous ionospheric layer, result multiple scattering by local inhomogeneities electron density embedded extended medium.
A wideband HF simulator has been constructed on the basis of a detailed physical model propagation which can generate time realization channel for any carrier frequency, bandwidth, transmitter receiver path and background, stochastic (irregularity) ionosphere models. To accomplish this, comprehensive solution obtained complex phase method (Rytov's method) to problem wave most general case three‐dimensional (3‐D) inhomogeneous with time‐varying electron density fluctuations. simulation is...
In the frame of European COST 296 project (Mitigation Ionospheric Effects on Radio Systems, MIERS) in Working Package 1.3, new ionospheric models, prediction and forecasting methods programs as well imaging techniques have been developed. They include (i) topside ionosphere meso-scale irregularity (ii) improved for real time foF2, M(3000)F2, MUF TECs, including use such Neurofuzzy, Nearest Neighbour, Cascade Modelling Genetic Programming (iii) dynamic high latitude models through tomographic...
A previously developed scintillation propagation model for L band signals on transionospheric paths has been further extended to describe the effects caused by localized structure of plasma bubbles in low‐latitude ionosphere. This takes into account quasi‐deterministic and random structures typical bubbles. The can produce signal statistical moments (power spectra, correlation functions, index, etc.) generate time series including case through bubble propagation. simulated field demonstrate...
The effects of the ionosphere remain one main factors which limit precision and reliability many GNSS applications. It is therefore indispensable on hand to improve existing mitigation techniques other assess their remaining weaknesses. Mitigation depend type application considered. Therefore, specific have be developed. paper summarizes work performed this topic in frame WP 3.2 «Mitigation techniques» COST 296.
This paper addresses the effects of scintillation on high‐latitude paths propagation. To specify ionosphere environment as a time‐dependent three‐dimensional distribution electron density, first‐principles ionospheric model UAF EPPIM (University Alaska Fairbanks Eulerian Parallel Polar Ionosphere Model) is utilized. For specification time‐varying small‐scale irregularities, superimposed onto background EPPIM, full inverse power law spectrum chosen. It augmented with introduction...
Abstract There are a variety of methods employed for determination phase and amplitude scintillation on satellite signals which generally employ different models theory. The paper shows that in spite this, very similar results can be found most circumstances four wide range physical input parameters weak conditions. Further comparison between help to determine their modeling errors hence also lead more accurate determinations using improved models.
Rytov's method is generalized for the case when regularly inhomogeneous ionosphere contains local irregularities of deterministical and statistical nature. An integral representation point source field constructed which takes into account multibeam effects including strong interference beams field, i.e., caustics foci formation so on. By means developed, some problems HF wave propagation are solved. Among these diffraction a on an ambipolar diffusing inhomogeneity ionosphere. The...
This paper is devoted to the investigation of two‐frequency, two‐position, time coherence function and ionospheric scattering describing HF fluctuating radio channel. The complex phase method applied obtain analytical expressions for correlation functions, which are then calculated numerically realistic models ionosphere. numerical Fourier transformation gives function. results obtained lead conclusion that in general case large variability shapes ionosphere exists depending on concrete...
The complex phase method has been further extended to the problem of electromagnetic (EM) field scintillations on Earth‐satellite GPS paths propagation. numerical and analytic technique based developed characterize transionospheric channel effects additional range errors due ionospheric electron density fluctuations in space time have studied taking into account ray bending inhomogeneous background ionosphere diffraction local random inhomogeneities. In developed, impact Earth's magnetic is...
An analytic technique has been developed to construct the asymptotic representation of spaced position and frequency coherence function in Markov's diffusive approximation. The employs formalism quasi‐classic complex paths an extended complex‐valued coordinate space. It allows construction coherency for arbitrary realistic models structure fluctuations refractive index medium propagation. employed obtain explicit solutions some function. For quadratic method produces known rigorous solution...
The effect of strong scintillation conditions on GNSS transionospheric paths propagation is further investigated employing the most recent update Hybrid Scintillation Propagation Model (HSPM). variation various parameters including spectral indices and other statistical moments field studied as a function severity signal fluctuations. correlation time complex amplitude found to rapidly decrease increases, but by contrast, intensity stays almost constant over wide range S 4 showing only...
Abstract The detailed effects of the high‐frequency radio wave propagation in a stochastic transionospheric channel are discussed. This is special case along or almost lines Earth's magnetic field. In this case, ionospheric random irregularities electron density ionosphere may have very high values aspect ratio, which stands beyond range validity traditional analytical approaches utilized to treat appropriate problems. consideration presented here, new results obtained for treating problem...
Phase and amplitude fluctuations spectra of the HF point source field in fluctuating reflection channel are investigated on basis Rytov's method generalized to case inhomogeneous ionosphere. Integral representations expressing fluctuation transformed a form that is more convenient for numerical estimations owing reduced number integrals. The resulting expressions evaluated numerically with controlled accuracy three‐dimensional power type model dielectric permittivity fluctuations. results...