Now showing items 40-44 of 44

    • Radar observations of space debris in polar orbits 2018–2021. A study on the evolution of the Microsat-R fragments 

      Paulsen, Martinius Ekeland (Master thesis; Mastergradsoppgave, 2021-07-02)
      Orbits are an invaluable resource for the global community. However, space pollution is becoming more pronounced as the accumulation of debris continues. Deliberate collisions are a relevant source contributing to this development. When Microsat-R was destroyed with a missile in 2019, it ejected numerous fragments into orbit. Based on observations made with EISCAT UHF, this thesis will investigate ...
    • Review and test of funnel shape geometries in solar wind acceleration 

      Trollebø, Robert (Master thesis; Mastergradsoppgave, 2009-12-15)
      The origin and heating of the solar wind is still a puzzle. We review in this study the idea that the solar wind originates in coronal funnels. We place emphasis on the fast solar wind. This study provides primarily a historic overview over the development of the idea of funnel expansion. We present examples of recent solar wind studies that investigate the funnel geometry. These studies include ...
    • Spectral observations of Polar Mesospheric Summer Echoes (PMSE) 

      López Muñoz, Aquilino (Master thesis; Mastergradsoppgave, 2007-06-15)
      We present spectral measurements of PMSE under the influence of HF heating cycles. The data has been obtained with EISCAT VHF radar, during the EISCAT campaign 2004 in Tromsø. Examples where the PMSE overshoot appears when the electrons are heated with a specific cycle are shown. A detailed analysis of PMSE spectral width during the heating cycles concluded that there is no evidence of a possible ...
    • Survey and simulation of space debris using EISCAT UHF 

      Røynestad, Elisabeth Kristina (Master thesis; Mastergradsoppgave, 2018-06-01)
      This thesis starts with a review of the evolution of space debris, what is consists of, how it is made, how it is detected and tracked, and why it is such an important topic. Some of the worst collisions have contributed to causing 49% of the total space debris. If the launch rate continues, the "Kessler Syndrome" might become a reality destroying our future outlook for space communication and ...
    • A theoretical study of the coupling between minor ions and protons in the solar transition region 

      Byhring, Hanne Sigrun (Master thesis; Mastergradsoppgave, 2007-06-01)
      We have used a numerical model to calculate the flow velocities of six minor ion species, using two different background models for the fast solar wind, one with a slow expansion, and one with a very rapidly expanding geometry. By comparing the flow velocity of the minor ions and the protons, we have investigated the degree of coupling between minor ions and the background solar wind in the solar ...