Sökning: "radar observations"

Visar resultat 1 - 5 av 46 avhandlingar innehållade orden radar observations.

1. 1. High-resolution meteor exploration with tristatic radar methods

   Författare :Johan Kero; Asta Pellinen-Wannberg; Sigrid Close; Umeå universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; meteors; meteoroids; interplanetary dust; radar; head echoes; ablation; meteoroid fragmentation; radar; huvudekon; ablation; meteorisk fragmentation; meteorer; meteoroider; interplanetärt stoft; Space engineering; Rymdteknik;

   Sammanfattning : A meteor observed with the naked eye is colloquially called a shooting star. The streak of light is generated by an extra-terrestrial particle, a meteoroid, entering the Earth’s atmosphere. The term meteor includes both luminosity detectable by optical means and ionization detectable by radar. LÄS MER

3. 2. Radar Probing of the Sun

   Författare :Mykola Khotyaintsev; Bo Thide'; Valentyn Mel'nyk; Christian Hanuise; Uppsala universitet; []
   Nyckelord :Space and plasma physics; solar radar; active experiments; space physics; solar corona; plasma; Rymd- och plasmafysik;

   Sammanfattning : This thesis is dedicated to the theory of solar radar experiments. The Sun exhibits a variety of interesting and complicated physical phenomena, examined mainly through analysis of its radiation. Active solar probing by radar provides an alternative possibility to study the Sun. LÄS MER

4. 3. Spaceborne Synthetic Aperture Radar for Sea Ice Observations, Concentration and Dynamics

   Författare :Anders Berg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; synthetic aperture radar; interferometry; satellite; sea ice dynamics; sea ice monitoring; sea ice concentration;

   Sammanfattning : Spaceborne Synthetic Aperture Radar (SAR) is the primary choice for sea ice monitoring due to its all-weather, day-and-night capability and regular delivery of high resolution images. This thesis presents methods for estimation of sea ice concentration and drift, a multi-sensor study of Baltic Sea ice radar signatures and an interferometric study of landfast sea ice. LÄS MER

5. 4. Detection and classification of sea ice from spaceborne multi-frequency synthetic aperture radar imagery and radar altimetry

   Författare :Wiebke Aldenhoff; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Beaufort Sea; sea ice classification; sea ice; sea ice concentration; Fram Strait; SAR imaging; radar altimetry;

   Sammanfattning : The sea ice cover in the Arctic is undergoing drastic changes. Since the start of satellite observations by microwave remote sensing in the late 1970's, the maximum summer sea ice extent has been decreasing and thereby causing a generally thinner and younger sea ice cover. LÄS MER

7. 5. Temporal Characteristics of Boreal Forest Radar Measurements

   Författare :Albert Monteith; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; antenna array; Synthetic aperture radar; temporal coherence; tomography; backscatter; remote sensing;

   Sammanfattning : Radar observations of forests are sensitive to seasonal changes, meteorological variables and variations in soil and tree water content. These phenomena cause temporal variations in radar measurements, limiting the accuracy of tree height and biomass estimates using radar data. LÄS MER