Search for dissertations about: "Ionospheric irregularities"

Showing result 1 - 5 of 6 swedish dissertations containing the words Ionospheric irregularities.

  2. 1. Secondary Electromagnetic Radiation Generated by HF Pumping of the Ionosphere

    Author : Lars Norin; Bo Thidé; Savely M. Grach; Bengt Gustafsson; James W. LaBelle; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; space physics; ionospheric modification experiments; plasma turbulence; stimulated electromagnetic emission; ionospheric irregularities; radio waves; parametric processes; thermal parametric instability; transient dynamics; wave-wave interactions; Physics; Fysik;

    Abstract : Electromagnetic waves can be used to transmit information over long distances and are therefore often employed for communication purposes. The electromagnetic waves are reflected off material objects on their paths and interact with the medium through which they propagate. READ MORE

  4. 2. Opening New Radio Windows and Bending Twisted Beams

    Author : Erik Nordblad; Thomas B. Leyser; Kristof Stasiewicz; Vladimir Pavlenko; Paul A. Bernhardt; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Orbital angular momentum; Hall effect; Nonparaxial beam; Geometrical optics; High frequency radio waves; Ray tracing; Magnetic zenith effect; Ionospheric irregularities; Wave propagation; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Abstract : In ground based high frequency (HF) radio pumping experiments, absorption of ordinary (O) mode pump waves energises the ionospheric plasma, producing optical emissions and other effects. Pump-induced or natural kilometre-scale field-aligned density depletions are believed to play a role in self-focussing phenomena such as the magnetic zenith (MZ) effect, i. READ MORE

  5. 3. Effects of Small-Scale Ionospheric Irregularities on GNSS Radio Occultation Signals : Evaluations Using Multiple Phase Screen Simulator

    Author : Vinícius Ludwig Barbosa; Mats Pettersson; Viet Thuy Vu; Stig Syndergaard; Blekinge Tekniska Högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GNSS Radio Occultation GNSS-RO ; Ionosphere; Scintillation;

    Abstract : Radio Occultation (RO) is a remote sensing technique which uses Global Navigation Satellite System (GNSS) signals tracked by a Low-Earth Orbit (LEO) satellite to sound the earth's atmosphere both in low (troposphere, stratosphere) and high (ionosphere) altitudes. GNSS-RO provides global coverage and SI traceable measurements of atmospheric data with high-vertical resolution. READ MORE

  6. 4. Interaction between Electromagnetic Waves and Localized Plasma Oscillations

    Author : Jan-Ove Hall; Thomas Leyser; Jan Trulsen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma physics; radio waves; ionospheric modification; density depleations; field-aligned irregularities; lower hybrid solitary structures; lower hybrid cavities; Z mode waves; magnetosonic waves; scattering; mode conversion; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Abstract : This thesis treats interaction between electromagnetic waves and localized plasma oscillations. Two specific physical systems are considered, namely artificially excited magnetic field-aligned irregularities (striations) and naturally excited lower hybrid solitary structures (LHSS). READ MORE

  7. 5. On the Ionospheric Influence on GNSS Radio Occultation Signals : Modelling and Assessment

    Author : Vinícius Ludwig Barbosa; Mats Pettersson; Viet Thuy Vu; Anthony James Mannucci; Blekinge Tekniska Högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Remote Sensing; Radio Occultation; Ionosphere; Scintillation; Wave Optics Propagator; Spectral Analysis; Plasma Bubble; Systemteknik; Systems Engineering;

    Abstract : Radio Occultation (RO) is a well-established remote sensing technique that uses Global Navigation Satellite System (GNSS) signals to sound the Earth’s atmosphere. GNSS-RO measurements provide high-resolution, vertical profiles of physical parameters from the lower atmosphere (troposphere and stratosphere), e.g. READ MORE