Now showing items 9-28 of 44

    • Characterization of a magnetized plasma in cylindrical geometry 

      Tribulato, Giulio (Master thesis; Mastergradsoppgave, 2007-06)
      Njord is a novel plasma device in which a low-temperature plasma is produced by RF waves inductively coupled into a cylindrical, magnetized vacuum. The main part of this project is to carry out an experimental characterization of the plasma in this device. The plasma expansion and acceleration of the source plasma into the main chamber will be of specific interest. The ultimate aim will then be to ...
    • Charging Effects and Detection of Mesospheric Dust with the Instrument SPID on the G-Chaser Rocket 

      Gunnarsdottir, Tinna (Master thesis; Mastergradsoppgave, 2019-06-01)
      Smoke Particle Impact Detector (SPID) is a faraday cup impact probe designed and built by the University of Tromso (UIT). Its main purpose is to measure nanometer sized smoke particles (in-situ) in the atmosphere, and to do that it needs to be launched on a sounding rocket. Its design is an open faraday cup with grids to shield out ambient plasma and a larger slanted impact grid to measure the ...
    • A Comparison of Naturally Enhanced Ion Acoustic Lines and Auroral Spectral Line Emissions 

      Hansen, Rikke Hedelund (Master thesis; Mastergradsoppgave, 2019-05-31)
      In this thesis, we present Naturally Enhanced Ion Acoustic Lines (NEIALs) observed with the EISCAT Svalbard Radar and a comparison with auroral emissions lines measured with a Meridian Scanning Photometer. NEIALs are short-lived events noticeable in the incoherent scatter spectra as an enhancement in one or both shoulders. It has been assumed that NEIALs are associated with an active red emission ...
    • Cross-Phase Based Multi-Camera Video Synchronization Calibration with Sub Frame Rate Accuracy 

      Sivasothy, Pavithiran (Master thesis; Mastergradsoppgave, 2020-06-29)
      In auroral research, it is necessary to accurately measure the time-shift differences between varying light sources. Such measurements can be carried out using two or more digital cameras, or between different regions of an image obtained using a single camera. An example of this is measurements of the time-shifts between prompt auroral emissions originating from different altitude regions during ...
    • Design and Implementation of a Software Defined Ionosonde. A contribution to the development of distributed arrays of small instruments 

      Floer, Markus (Master thesis; Mastergradsoppgave, 2020-06-29)
      In order to make advances in studies of mesoscale ionospheric phenomena, a new type of ionosonde is needed. This ionosonde should be relatively inexpensive and small form factor. It should also be well suited for operation in a network of transmit and receiver sites that are operated cooperatively in order to measure vertical and oblique paths between multiple transmitters and receivers in the ...
    • Design and implementation of an oblique ionosonde receiver. For studies of spatial and temporal ionospheric structures 

      Floberg, Jens (Mastergradsoppgave; Master thesis, 2022-05-27)
      The study of the ionosphere has been of central interest since its discovery in the early 20th century. In later decades there has been an increasing appreciation and need for understanding the spatial and temporal structure of the ionosphere and how the structure is affected by various processes in the atmosphere. An important process in this context is that of atmospheric gravity waves ...
    • Determining optical-flow for turbulent motions in the aurora borealis 

      Jakobsen, Kim André (Master thesis; Mastergradsoppgave, 2020-06-28)
      In dynamic aurora there are structures that shows shear-flow and rotations. These flows have a locally varying vorticity-field, which can be observed in small scale aurora. Vorticity in plasma-flows have a direct relation to field-aligned currents. An effective method to determine these flows would be a great tool in research on magnetosphere-ionosphere coupling and auroral physics. With the current ...
    • Disambiguation of range-Doppler radar measurements 

      Alvsaker, Andrea Marie (Mastergradsoppgave; Master thesis, 2022-05-31)
      Observing the Moon by a monostatic synthetic-aperture radar system has the inherent problem that any given combination of range and Doppler shift in a measurement will map to two different regions on the lunar surface. This ambiguity has previously been avoided using an interferometric radar configuration or selective illumination. The objective of this thesis was to write and validate a method for ...
    • The effect of a water-ice mantle on dust trajectories in the Kuiper belt 

      Gjelsvik, Amalie (Mastergradsoppgave; Master thesis, 2023-07-12)
      The New Horizons spacecraft has travelled through the Solar System and has reached a distance of 55 AU as of 2023. For one of the first times, the dust flux in the outer Solar System has been measured, using the instrument Student Dust Counter (SDC) onboard New Horizons. Between 30 and 50 AU is the Kuiper belt, which is a disk consisting of icy objects. These objects can undergo collisions, causing ...
    • Estimating thermospheric neutral densities using ISR-observations during active HF-radio wave ionospheric heating experiment 

      Pedersen, Marcus Nicolai (Master thesis; Mastergradsoppgave, 2017-12-15)
      In this study we present a method to estimate neutral thermospheric densities using ISR-observations following a sequence of high-frequency radio wave ionospheric heating modi cations in the vicinity of the ionosphere peak density altitude (hmF2), and the results from two different days of observations with low geomagnetic activity levels (AP<4) that are compared to the MSIS model. Slight ...
    • Frequency Dependence of Ionospheric Electron Heating Around the Third Double Resonance 

      Frøystein, Ingeborg (Mastergradsoppgave; Master thesis, 2022-05-31)
      The partly ionized ionosphere responds differently to high power, high frequency radio waves based on the wave frequency, the wave power, the wave polarization, and the propagation angle relative to the magnetic field. Ionospheric modification experiments are conducted to investigate the responses and their dependencies, setting experimental constraints on the contributions from non-resonant collisional ...
    • The influence of mass loss on the dynamics of dust near the Sun 

      Klepper, Kassi (Mastergradsoppgave; Master thesis, 2021-12-28)
      The Parker Solar Probe (PSP) mission by NASA and the Solar Orbiter (SolO) mission by ESA are two recently launched missions that measure dust in the inner solar system. The dust is produced by fragmentation of meteoroids, which are large fragments of the asteroids and comets. The dust particles are small enough that their motion is affected by the radiation pressure force from the Sun. Dust fragments ...
    • Influence of Meteoric Aerosol particles on the Charge Balance in the Upper Mesosphere During ECOMA 2010 

      Svendsen, Åse (Master thesis; Mastergradsoppgave, 2011-12-15)
      This work is focused on the three sounding rocket launches during the ECOMA Geminids campaign in December 2010: One before the Geminids meteor shower, one at its peak and one some days after the peak. In this work, the main emphasis is on analyzing the results from electron and ion probes on the rockets, obtaining electron and ion density profiles, and comparing them with the measurements of meteoric ...
    • Installation and characterization of an electron bombardment ion source for a Space Simulation Chamber (SSC) 

      Dyrland, Karianne (Master thesis; Mastergradsoppgave, 2016-12-15)
      The primary focus of this thesis is the installation and characterization of an electron bombardment ion source for a Space Simulation Chamber (SSC). The goal is that the chamber can be used to test satellite and sounding rocket instrumentation, thus be capable of producing ionospheric plasma conditions, along with an ion beam that can simulate the velocity of a rocket or satellite relative to the ...
    • Interplanetary dust fluxes observed with Parker Solar Probe 

      Henriksen, Emil Gorseth (Master thesis; Mastergradsoppgave, 2020-06-29)
      The mission Parker Solar Probe (PSP) provides a new opportunity to make in-situ measurements of dust impacts closer to the Sun than ever before, eventually going as close as ∼ 10 solar radii or ∼ 0.05 AU. PSP can measure dust impacts from monopole measurements of the spacecraft’s electric potential to one of its antennas using its FIELDS instrument. In this work impact rates data is compared ...
    • Interstellar Dust in the Inner Heliosphere and Impact Detection Capabilities with ESA's Solar Orbiter Spacecraft 

      Henriksen, Aleksander Johan (Master thesis; Mastergradsoppgave, 2022-05-31)
      ESA’s Solar Orbiter spacecraft provides a new opportunity to investigate the inner heliosphere close to sun, by taking measurements with state-of-the-art instruments it will help uncover the mysteries of the Sun. Solar Orbiter is planned for a 7 year mission, reaching as close as 0.28 AU to the sun. Using a process called impact ionization, dust fluxes can be measured during the mission. Some ...
    • An Investigation of Magnetic Field Disturbances on the Ground and in the Mesosphere 

      Eriksen, Nina Kristine (Master thesis; Mastergradsoppgave, 2019-05-31)
      Geomagnetic field models can be a useful tool for when and where there are no measurements available, or access is limited, because of a highly spatially uneven magnetometer network around the globe. The same can be said for altitudes above the ground, but below the ionospheric current layer, where there exist no in situ measurements at the point of writing. Modelled geomagnetic disturbances have ...
    • An investigation of the spatial and temporal distribution of kinetic energy in the mesosphere. The high latitude mesosphere 

      Nordaunet, Ole Kalstad (Master thesis; Mastergradsoppgave, 2020-06-29)
      The mesosphere is perhaps the least explored region in the atmosphere with very few methods of observing. This thesis will primarily be exploring a new technique for measuring the distribution of kinetic energy in the mesosphere across a wide range of spatial and temporal scales. The method being used relies on correlation functions between pairs of meteor measurements. These measurements are made ...
    • A model for IS spectra for magnetized plasma with arbitrary isotropic velocity distributions 

      Enger, Eirik Rolland (Mastergradsoppgave; Master thesis, 2020-06-27)
      The plasma line in the incoherent scatter spectrum is known to provide information about the state of the ionosphere. However, it is weak in signal strength and therefore difficult to measure reliably and consistently. When high-energetic electrons (suprathermal electrons) are present in the ionosphere the plasma line echo power is enhanced and detectable by more radars. Recent measurements made by ...
    • Multifractals and their application to geospace data 

      Østvand, Lene (Master thesis; Mastergradsoppgave, 2008-06-02)
      In this thesis I first introduce multifractal theory and mathematical concepts for multifractal analysis. Different methods for different uses are described, with focus on a differentiating between coarse and fine theory approaches. Methods for analysing time series are also described, more specificly a direct method based on the coarse theory analysis, the wavelet transform modulus maxima ...