Blar i tittel Mastergradsoppgaver i teknologi - romfysikk
Viser treff 1-20 av 45
-
Air temperature at 90 km altitude in the Artic obtained using meteor radar : validation, characterization and climate change.
(Master thesis; Mastergradsoppgave, 2011-09-30)Temperatures at 90 km altitude above Ramfjordmoen (69°N, 19°E) have been obtained with the Nippon/Norwegian Tromsø Meteor Radar. The temperatures have been derived from meteor radar decay rates using two techniques: the pressure based and the temperature gradient based methods. The results have been compared to the Microwave Limb Sounder (MLS) instrument on board the Aura spacecraft. It was found ... -
Analysis of dust impacts observed with the Radio Plasma Wave instrument onboard ESA’s Solar Orbiter
(Master thesis; Mastergradsoppgave, 2023-12-15)Dust particles are one of the major constituents of the interplanetary medium in our solar system. They are presumably formed by fragmentation processes of meteoroids and for a certain range of sizes and parameters the dust particles move radially outwards from the Sun. The Radio plasma Wave (RPW) instrument on Solar Orbiter can measure dust particles that impact the spacecraft. By measuring the ... -
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 ... -
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 ... -
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 ... -
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) ... -
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 ... -
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 ... -
Characterization of a magnetized plasma in cylindrical geometry
(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
(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
(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
(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
(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
(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
(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
(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
(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
(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
(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
(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 ...