Mastergradsoppgaver i teknologi - romfysikk: Recent submissions
Now showing items 21-40 of 49
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Predicting the Auroral Oval Boundaries by Means of Polar Operational Environmental Satellite Particle Precipitation Data
(Master thesis; Mastergradsoppgave, 2020-06-29)New empirical Kp-based models for the equatorward and poleward boundaries of the auroral oval in the Northern and Southern Hemispheres were developed, with the purpose of reviewing the auroral ovals predicted by well-established Feldstein auroral oval model. The new models were derived from particle and energy flux measurements from six low-altitude (800-900 km) POES/MetOp satellites. The equatorward ... -
Interplanetary dust fluxes observed with Parker Solar Probe
(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 ... -
Cross-Phase Based Multi-Camera Video Synchronization Calibration with Sub Frame Rate Accuracy
(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 ... -
An investigation of the spatial and temporal distribution of kinetic energy in the mesosphere. The high latitude mesosphere
(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 ... -
Analysis of the potential of the Ku-band Gamma Portable Radar Interferometer for sea ice information extraction.
(Master thesis; Mastergradsoppgave, 2020-06-29)Radar remote sensing is a key technology for monitoring sea ice. In this regard, passive microwave and Synthetic Aperture Radars (SARs) are the most important sensor types. This technology has been used for sea ice applications for four decades, but there are still many uncertainties related to sea ice monitoring by SAR. Some of these may be solved by multi-sensor observations, in which case other ... -
Determining optical-flow for turbulent motions in the aurora borealis
(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 ... -
An Investigation of Magnetic Field Disturbances on the Ground and in the Mesosphere
(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 ... -
A Comparison of Naturally Enhanced Ion Acoustic Lines and Auroral Spectral Line Emissions
(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 ... -
Arctic Thin Sea Ice Thickness Regression Models for Sentinel-2
(Master thesis; Mastergradsoppgave, 2019-05-31)Sea ice thickness is an important parameter for modelling the sea ice mass balance, momentum and gas exchanges, and global energy budget. The interest of studies into thin sea ice has increased as trends in recent years show a increasing abundance in thin first year ice. Existing thin sea ice thickness products operate at resolutions down to 750 meters. Very high resolution (less than 100 meters) ... -
Charging Effects and Detection of Mesospheric Dust with the Instrument SPID on the G-Chaser Rocket
(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 ... -
On the Meteoric Smoke Particle Detector SPID: Measurements and analysis from the G-chaser rocket campaign
(Master thesis; Mastergradsoppgave, 2019-06-01)The Smoke Particle Impact Detector (SPID), newly designed at the University of Tromsø, was launched from Andøya 09:13 UTC the 13. January 2019. SPID is designed to detect meteoric smoke particles (MSPs) in winter mesospheric conditions. The rocket had a velocity of 1600 ms-1 at ~55 km where the nosecone was separated. At ~ 60km, SPID detected a signal of 17nA on the middle plate. The dynamics of the ... -
Angular dependence of wide altitude ion line enhancements (WAILEs) during ionospheric heating at the EISCAT Tromsø Facility
(Master thesis; Mastergradsoppgave, 2019-06-01)This thesis presents the first sub-radar beam resolution determination of the angular width of wide altitude ion line enhancements (WAILEs), found to be 0.5 degrees around magnetic zenith, observed during a HF radio wave heating experiment at the EISCAT Tromsø Heating facility on 27 November 2014. The results of ray tracing simulations are detailed. The simulations are based on the hypothesis that ... -
Survey and simulation of space debris using EISCAT UHF
(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 ... -
Estimating thermospheric neutral densities using ISR-observations during active HF-radio wave ionospheric heating experiment
(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 ... -
Plasma cloud detection and diagnostics from arcing by conditional averaging
(Master thesis; Mastergradsoppgave, 2017-06-06)Plasma cloud formation from arcing is experimentally studied. The arcs are formed by a high voltage set-up in the space simulation chamber at UiT. The plasma clouds are observed as large structures in the time series recorded by Langmuir probe and reference probe. By using the method of conditional averaging, the structures are accentuated. The electron cloud formed by arcing was found to be ... -
Beam and plasma properties downstream from positively biased source chamber
(Master thesis; Mastergradsoppgave, 2017-06-06)We study the effect of changing the separation grid bias in a double plasma device from -50 V to the same bias as the anode in the source chamber, 115 V on the plasma and beam parameters downstream in the target chamber. Two different probes were used to analyze the downstream plasma. We used an RFEA-probe to obtain information about the ions, such as the ion energy distribution and we constructed ... -
Installation and characterization of an electron bombardment ion source for a Space Simulation Chamber (SSC)
(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 ... -
Automatic Detection of Naturally Enhanced Ion-Acoustic Lines in EISCAT data
(Master thesis; Mastergradsoppgave, 2016-06-01)Naturally Enhanced Ion-Acoustic Lines (Neials) are small-scaled and short-lived phenomena in the ionosphere, which is widely researched internationally. At present, the search for Neials is a tedious task that has to be done through visual inspection. This is often a time-consuming process and limits the research on Neials. By automating the means of locating the Neials, the access to them will be ... -
Arctic Cirrus Clouds: A Comparison of Properties Derived from Measurements by Ground-Based and Spaceborne Lidar Systems
(Master thesis; Mastergradsoppgave, 2015-12-15)The purpose of this thesis is to investigate Arctic cirrus clouds. In this work, data from the ground-based lidar system at ALOMAR, Andøya Space Center. and the spaceborne lidar onboard the CALIPSO satellite is used. Cirrus clouds are an important factor in modeling climate changes, which is one of the major research fields of this time. Most of the cirrus cloud research concentrates on investigating ... -
On the internal physical conditions in dust probes: transport, heating and evaporation of fragmented dust particles
(Master thesis; Mastergradsoppgave, 2013-12-13)We study the conditions within, and dynamics of fragmented mesospheric dust particles inside, the Faraday-cup type dust probe MUDD using numerical simulations with a dedicated model. The transport of singly charged fragments from impacting NLC particles on the main grid in MUDD, have been calculated on the basis of supplementary models of the neutral gas conditions and electric field structure within ...