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Chip-based wide field-of-view nanoscopy
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-24)Present optical nanoscopy techniques use a complex microscope for imaging and a simple glass slide to hold the sample. Here, we demonstrate the inverse: the use of a complex, but mass-producible optical chip, which hosts the sample and provides a waveguide for the illumination source, and a standard low-cost microscope to acquire super-resolved images via two different approaches. Waveguides composed ... -
Chip Based Nanoscopy: Towards Integration and High-throughput Imaging
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017)Super-resolution optical microscopy, commonly referred to as optical nanoscopy, has enabled imaging of biological samples with a resolution that was only achievable previously using electron microscopy. Optical nanoscopy is a rapidly growing field, with several different techniques and implementations that overcome the diffraction limit of light. However, the common nanoscope continues to be a rather ... -
Reconstruction of the full-polarimetric covariance matrix from compact-polarimetric synthetic aperture radar data with convolutional neural networks
(Master thesis; Mastergradsoppgave, 2017-09-05)The focus of this thesis is to find an alternative way to reconstruct a pseudo quadrature polarimetric (quad-pol) covariance matrix from compact polarimetric (compact-pol) data. In the latest years, the compact polarimetry SAR mode was developed and used more and more widely. It provides a good compromise between area covered and information content per pixel [13]. The literature has focused ... -
A Classification Strategy for Multi-Sensor Remote Sensing Data. An analysis and implementation of Meta-Gaussian classification schemes
(Master thesis; Mastergradsoppgave, 2017-08-18)In integrated remote sensing, one of the objectives is to create reliable services by combining information from various data sources. The combination of multiple data sources is often denoted "data fusion", and is a topic that has high interest in remote sensing applications. In this thesis, we devise a classification strategy for multi-sensor remote sensing data, based on the strategy presented ... -
Speckle filtering of Polarimetric SAR data
(Master thesis; Mastergradsoppgave, 2017-06-17)In the field of Remote Sensing the main device, used to obtain the surface images, are the so-called Synthetic Aperture Radar. This systems are devices able to catch high-resolution images, which keep peculiar informations about the observed surface. Through the use of a Radar, mounted on board of a spaceborne or airborne vehicle, large overflow areas are electromagnetically radiating. The ... -
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 ... -
Laser Based Altimetry for Unmanned Aerial Vehicle Hovering Over a Snow Surface
(Master thesis; Mastergradsoppgave, 2017-06-02)A microwave radar for non-invasive snow stratigraphy measurements has been developed. Results were promising, but it failed to detect light powder snow in the air-snowpack interface. The aim of this thesis is to find and verify a system for estimating altitude on centimeter scale over a snow surface, independent of snow conditions. Also, relative pitch and roll angle estimation between the UAV and ... -
A comparison between optical and SAR classification results for thin sea ice in Storfjorden
(Master thesis; Mastergradsoppgave, 2017-05-31)According to the scientific consensus, the Arctic is currently in a state of unprecedented change. In recent years, climate change has been identified as the main cause of Arctic sea ice decline. For this reason, the need to have access to timely and cost effective data is of great importance. Remote sensing via Earth orbiting satellites offers extensive data coverage in areas that are typically ... -
Modeling Ice-shelf Ocean Interaction at Petermann Glacier, Greenland
(Master thesis; Mastergradsoppgave, 2017-05-15)Petermann Glacier drains about 4% of the Greenland ice sheet area, with at least 80% of its mass loss through basal melting of the floating ice shelf. Utilizing a high-resolution coupled ice-shelf-ocean model, we aim at understanding the ocean circulation in Nares Strait and the mechanism of oceanic heat supply below the ice shelf as well as quantifying the basal mass loss. The numerical model is ... -
Optimization of a polymer layer highly doped with Cryptophane-A for methane sensing
(Master thesis; Mastergradsoppgave, 2017-05-15)The main objective of this thesis is to optimize the thickness of sensitive polymer layer highly doped with Cryptophane-A for methane pre-concentration and to make the existing sensor more stable and selective towards methane. In recent years, methane detection has become a hot topic due to the strong impact of methane on the global warming and the climate change. There has also been rising ... -
Investigation of inflammatory response of macrophages and trophoblasts using structured illumination microscopy
(Master thesis; Mastergradsoppgave, 2017-05-15)Approximately 800 women die from pregnancy or childbirth-related pregnancy complications around the world every day. One of the major reasons for these complications is inflammation following infection. Approximately 40% cases of preterm births occur due to microbial invasion in the genitourinary track. During inflammation, macrophages present at the feto-maternal junction release an increased amount ... -
Eigen-analysis reveals components supporting super-resolution imaging of blinking fluorophores
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-30)This paper presents eigen-analysis of image stack of blinking fluorophores to identify the components that enable super-resolved imaging of blinking fluorophores. Eigen-analysis reveals that the contributions of spatial distribution of fluorophores and their temporal photon emission characteristics can be completely separated. While cross-emitter cross-pixel information of spatial distribution ... -
Laser diagnostics of the mesospheric magnetic field. Understanding remote laser magnetometry in northern Norway
(Master thesis; Mastergradsoppgave, 2017-05-15)This thesis outlines initial motivations and propositions for the Mesospheric Optical Magnetometry (MOM) project, using lidar equipment at ALOMAR observatory in northern Norway to initiate a novel technique for measuring Earth’s magnetic field at approximately 90 km altitude. Included is an in-depth discussion of the physical phenomena within Earth’s mesospheric sodium layer, relevant atomic physics, ... -
Estimation of Neutral Densities in the Thermosphere
(Master thesis; Mastergradsoppgave, 2017-05-17)Ionospheric energy balance is studied with incoherent scatter radar measurements that allow the estimation of neutral density and temperature from a statistical inversion problem. This method has been successfully studied at low latitudes using data over several years to make a robust model. This has not been done within the high latitude auroral regions and there are many factors that can complicate ... -
An initial assessment of the possibilities of fish catch prediction using Gaussian processes
(Master thesis; Mastergradsoppgave, 2016-12-15)The fishing and aquaculture industry is one of the largest industries of Norway. Enhanced knowledge of the distribution of fish in the ocean is important for an economical and sustainable fishing industry. This study investigates the possibilities of using Gaussian processes for regression within fish catch prediction. A dataset that combines catch reports from the Norwegian shipping company Havfisk ... -
Signature of Arctic first-year ice melt pond fraction in X-band SAR imagery
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-23)In this paper we investigate the potential of melt pond fraction retrieval from X-band polarimetric synthetic aperture radar (SAR) on drifting first-year sea ice. Melt pond fractions retrieved from a helicopter-borne camera system were compared to polarimetric features extracted from four dual-polarimetric X-band SAR scenes, revealing significant relationships. The correlations were strongly dependent ... -
X-, C-, and L-band SAR signatures of newly formed sea ice in Arctic leads during winter and spring
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-02)We examine an extensive synthetic aperture radar (SAR) data set from the Arctic Ocean spanning a time period from January to June 2015, with the aim of identifying multi-polarization parameters that can be used to accurately separate newly formed sea ice from the surroundings. Newly formed sea ice areas both provide favourable routing for ship traffic, and are key to Arctic climate science because ... -
Silicon nitride waveguide platform for fluorescence microscopy of living cells
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017)Waveguide chip-based microscopy reduces the complexity of total internal reflection fluorescence (TIRF) microscopy, and adds features like large field of view illumination, decoupling of illumination and collection path and easy multimodal imaging. However, for the technique to become widespread there is a need of low-loss and affordable waveguides made of high-refractive index material. Here, ... -
Solar Wind from Coronal Funnels and Transition Region Lyalpha
(Journal article; Tidsskriftartikkel; Peer reviewed, 2005-08-10)Using a newly developed gyrotropic solar wind model that extends continuously from the mid-chromosphere to 1 AU and that accounts for radiative losses in the transition region, we have studied the difference between the fast solar wind emanating from a funnel geometry and a ``traditional'' rapidly expanding wind. The main aim is to determine whether or not observations of the Lyalpha intensity in ... -
Assessment of RISAT-1 and Radarsat-2 for Sea Ice Observation from Hybrid-Polarity Perspective
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-25)Utilizing several Synthetic Aperture Radar (SAR) missions will provide a data set with higher temporal resolution. It is of great importance to understand the difference between various available sensors and polarization modes and to consider how to homogenize the data sets for a following combined analysis. In this study, a uniform and consistent analysis across different SAR missions is carried ...
