Sökning: "aperture"

Visar resultat 16 - 20 av 198 avhandlingar innehållade ordet aperture.

  1. 16. Retrieval of ocean surface winds and currents using satellite synthetic aperture radar and infrared radiometry

    Författare :Gisela Carvajal; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; surface currents; infrared radiometry; synthetic aperture radar; surface winds; maximum cross correlation; wind direction;

    Sammanfattning : This thesis focuses on the development, analysis and evaluation of methods for the retrieval of ocean surface winds with synthetic aperture radar (SAR) and surface currents with infrared (IR) radiometer sensors. The SAR wind speed retrievals are based on geophysical model functions using wind directions obtained with two approaches. LÄS MER

  3. 17. Synthetic Aperture Radar Signal and Image Processing for Moving Target Indication and Side Lobe Suppression

    Författare :Thomas Sjögren; Blekinge Tekniska Högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Synthetic Aperture Radar; Space time adaptive processing;

    Sammanfattning : The thesis summarizes a selection of my research within Synthetic Aperture Radar (SAR). Mainly the research is aimed at applying and developing signal processing methods to single channel and multi channel SAR for wideband systems. SAR systems can generate images looking very similar to optical pictures, i.e. LÄS MER

  4. 18. Factorized Geometrical Autofocus for Synthetic Aperture Radar Processing

    Författare :Jan Torgrimsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Back-Projection; PGA; SAR; UWB; Autofocus; FGA;

    Sammanfattning : Synthetic Aperture Radar (SAR) imagery is a very useful resource for the civilian remote sensingcommunity and for the military. This however presumes that images are focused. There are severalpossible sources for defocusing effects. For airborne SAR, motion measurement errors is the maincause. LÄS MER

  5. 19. Diagnostic Accuracy of Tuned Aperture Computed Tomography (TACT®)

    Författare :Madhu K. Nair; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES;

    Sammanfattning : The diagnostic accuracy of Tuned Aperture Computed Tomography (TACT) was evaluated for a variety of diagnostic tasks. Drawbacks of 2D radiography, lack of accessibility and high cost associated with advanced imaging modalities prompted these studies. LÄS MER

  7. 20. Retrieval of Wind Velocity Vectors Over the Ocean Surface with Spaceborne Synthetic Aperture Radar

    Författare :Gisela Carvajal; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind vector; wind direction; synthetic aperture radar SAR ; CMOD-IFR2; local gradient.; ocean winds; wind speed;

    Sammanfattning : Wind over the ocean (normally defined at 10 meter height) is one of the main parameters affectingsea state, generating waves and driving currents. Wind field maps with large area coverageand high resolution therefore represent valuable information for a wide range of applications such asinformation for shipping, which carries 80% of the world’s trade, oil platforms and other maritime infrastructures,modeling, analysis and validation of weather models, improving performance of sensorsonboard maritime infrastructures, etc. LÄS MER