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Showing result 11 - 15 of 63 swedish dissertations matching the above criteria.

  2. 11. Instrumentation for energetic Neutral atom measurements at Mars, Venus and The Earth

    Author : Klas Brinkfeldt; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Energetic neutral atoms; instruments and techniques; mass spectrometry; microchannel plates; solid state detectors; solar wind interaction; planets; magnetosphere; exosphere; ring current; Space physics; Rymdfysik;

    Abstract : This thesis deals with the development and calibrations of sensors to measure energetic neutral atoms (ENAs) at Mars, Venus, and the Earth. ENAs are formed in charge exchange processes between energetic, singly--charged ions and a cold neutral gas. READ MORE

  4. 12. VLF Chorus Activity Associated with Substorm Particle Injections

    Author : Andrew Collier; KTH; []
    Keywords : space physics; magnetosphere; VLF waves; substorms;

    Abstract : The Substorm Chorus Event (SCE) is a Very Low Frequency(VLF) radio phenomenon observed on the ground after the onsetof the substorm expansion phase. It consists of a band of VLFchorus emissions with rising upper and lower cutofffrequencies. READ MORE

  5. 13. Satellite observations of auroral acceleration processes

    Author : Lars Eliasson; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Aurora; particle acceleration; space plasma; magnetosphere; ionosphere; polar cap; satellite observations;

    Abstract : Measurements with satellite and sounding rocket borne instruments contain important information on remote and local processes in regions containing matter in the plasma state. The characteristic features of the particle distributions can be used to explain the morphology and dynamics of the different plasma populations. READ MORE

  6. 14. Solar Wind and Geomagnetic Activity - Predictions Using Neural Networks

    Author : Hans Gleisner; Astronomi - Genomgår omorganisation; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Geophysics; kosmisk kemi; rymdvetenskap; magnetosphere; solar wind; space weather; geomagnetic activity; geomagnetism; ring current; auroral electrojet; neural networks; forecasting; Astronomy; space research; Astronomi; cosmic chemistry; physical oceanography; meteorology; Geofysik; fysisk oceanografi; meteorologi; Fysicumarkivet A:2000:Gleisner;

    Abstract : This thesis shows how artificial neural networks (ANNs) can be applied to predict geomagnetic activity from solar-wind data. It introduces and summarizes five papers where development of ANN models are reported, and where predictions of geomagnetic activity are discussed. READ MORE

  7. 15. The Neutral Particle Detector on the Mars and Venus Express missions

    Author : Alexander Grigoriev; Stas Barabash; Brian J. Anderson; Umeå universitet; []
    Keywords : Space and plasma physics; ENA imaging; exosphere; magnetosphere; Mars; Venus; solar wind interaction; Rymd- och plasmafysik; rymd- och plasmafysik; Space and Plasma Physics;

    Abstract : The Neutral Particle Detector (NPD) is a new type of instrumentation for energetic neutral atom (ENA) diagnostics. This thesis deals with development of the NPD sensor designed as a part of the plasma and neutral particle packages ASPERA-3 and ASPERA-4 on board Mars Express and Venus Express, the European Space Agency (ESA) satellites to Mars and Venus, respectively. READ MORE