Sökning: "snow physics"

Hittade 5 avhandlingar innehållade orden snow physics.

1. 1. The Extremes of Neutrino Astronomy : From Fermi Bubbles with IceCube to Ice Studies with ARIANNA

   Författare :Elisabeth Unger; Allan Hallgren; Olga Botner; Antonio Capone; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; astroparticle physics; neutrino telescopes; IceCube; Fermi bubbles; ARIANNA; horizontal propagation; surface wave propagation; Fysik med inriktning mot elementarpartikelfysik; Physics with specialization in Elementary Particle Physics; High Energy Physics; Högenergifysik;

   Sammanfattning : The Fermi bubbles are extended regions of hard gamma-ray emission which were discovered with Fermi-LAT data to exist above and below the Galactic Center. In order to explain the origin of the gamma-rays, different theories are proposed. LÄS MER

3. 2. Snow Contamination of Cars: Adhesive Particle Collisions with Exterior Surfaces

   Författare :Tobias Eidevåg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; icing; particle laden flow; turbulent dispersion; premelting; sensor availability; exterior soiling; snow physics; particle resuspension; snow adhesion;

   Sammanfattning : An ongoing challenge regarding autonomous vehicles is the obstruction of sensors by contaminants on exterior surfaces. This often occurs when driving in harsh weather conditions, where the contaminant can be, for example, water spray, dirt, or snow. LÄS MER

4. 3. Snow contamination of cars: Collisions of ice particles with surfaces

   Författare :Tobias Eidevåg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ice adhesion; Snow adhesion; coefficient of restitution; particle impacts; premelting; radar blockage;

   Sammanfattning : Seasonal snow cover on roads causes car accidents that lead to human suffering and economic loss. Snow cover decreases visibility and road-tire friction. Advanced active safety systems have been developed to cope with sudden changes in driving conditions and have been engineered to act as quickly as possible. LÄS MER

5. 4. Design and development of a microwave multifrequency polarimetric scatterometer for biosphere remote sensing

   Författare :Anders Stjernman; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polarimetry; scatterometer; microwave remote sensing; calibration; network analyzer based; S-parameters; scattering matrix;

   Sammanfattning : Microwave radar and radiometer techniques are used to gather crucial information about the earth and its atmosphere. The ERS-1, JERS-1, RadarSAT and NASA’s Mission to Planet Earth projects are designed to study the changing global environment. In all these endeavors, the key instrument is the radar or scatterometer. LÄS MER

7. 5. Modelling Microwave Backscattering from Sea Ice for Synthetic-Aperture Radar Applications

   Författare :Anders Carlström; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; synthetic-aperture radar; microwave; surface roughness; sea ice; backscattering models;

   Sammanfattning : The spaceborne synthetic-aperture radar (SAR) is considered one of the key instruments for monitoring the ice cover in polar oceans and regional seas. This thesis is concerned with applications of electromagnetic scattering theory and SAR system theory for modelling the response of different types of sea ice in SAR imagery. LÄS MER