Sökning: "satellite earth stations."

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden satellite earth stations..

  1. 1. Design and Optimization of Wideband Hat-Fed Reflector Antenna with Radome for Satellite Earth Station

    Författare :Erik G Geterud; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Antenna feeds; satellite earth stations.; optimization; corrugated surfaces; radomes; reflector antennas;

    Sammanfattning : This thesis presents the development of a hat-fed refector antenna with radome to be used as satellite earth station. The antenna with self supported feed is relatively compact, circular symmetric and with low cross polarization. To achieve optimum performance over the satellite Ku-band,covering 10.75-14. LÄS MER

  3. 2. Local Sea Level Observations Using Reflected GNSS Signals

    Författare :Johan Löfgren; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GNSS-R; signal-to-noise ratio; sea level; GNSS; reflected signals; multipath; GPS; GLONASS; tide gauge; phase-delay;

    Sammanfattning : Sea level rise due to global warming is predicted to have a large impact on human society, especially for populations living in coastal regions and on islands. It is therefore of great importance to monitor the sea level and to increase the understanding of the local hydrodynamic and meteorological responses to a global sea level rise. LÄS MER

  4. 3. Satellite remote sensing of primary production in semi-arid Africa

    Författare :Martin Sjöström; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; remote sensing; primary production; vegetation index; savanna; grassland;

    Sammanfattning : With the challenges Africa faces with respect to the predicted warming due to climate change, the continents role in the global carbon cycle has been increasingly recognized. Earth observing satellites have played a significant role in the study of vegetation, particularly in Africa where climate stations are sparse. LÄS MER

  5. 4. Combination of space-geodetic techniques in the era of VGOS and multi-GNSS

    Författare :Periklis Diamantidis; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Local Ties; EOP; Reference Systems; GNSS; VLBI; Combination on the Observation Level; multi-GNSS; Space Geodesy; VGOS;

    Sammanfattning : The definition and maintenance of accurate and stable Earth-fixed and inertial reference frames is crucial in studying, among else, geophysical and geodynamical phenomena, precise positioning, and space navigation. The tools used to this end are space-geodetic techniques, like e.g. LÄS MER

  7. 5. Rainfall variability, soils and land use changes in the Ethiopian highlands

    Författare :Staffan Rosell; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; rainfall change; soil productivity; tef; land-use changes; South Wollo; water harvesting;

    Sammanfattning : Most farmers in the Ethiopian highlands are dependent on rain-fed agriculture. The indigenous cereal tef is the most important crop for the farmers in the highlands. The central highland is an environmentally fragile area and a marginal area of Ethiopia with a recurring problem for the farmers to sustain an adequate agricultural production. LÄS MER