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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Simulation and Compensation of Ionospheric Phase Phase Scintillation Noise in Spotlight SAR Data

Hsueh, Brian Chang Chi 19 January 2010 (has links)
This thesis addresses the problem of refocusing smeared SAR images caused by ionosphere phase scintillation noise. A SAR data is smeared when the received signal experiences phase irregularities due to platform orbit deviation, target movement, or, in this thesis, ionospheric scintillation noise due to trans-ionosphere propagation is analyzed. A SAR simulator is constructed to generate stripmap and spotlight data that satisfy theoretically predicted performances under ideal conditions. The simulator is incorporated with ionospheric phase scintillation models to analyze the broadening effect on system’s PSF. Degraded simulation spotlight data are used to test the proposed compensation algorithm. This thesis proposes a two-dimensional polynomial phase fitting algorithm to compensate scintillation noise. This work discusses some requirements of the scene in order to carry out the compensation and what is gained and lost in the process. A successful application of the proposed algorithm to TerraSAR-X data is also presented.
2

Simulation and Compensation of Ionospheric Phase Phase Scintillation Noise in Spotlight SAR Data

Hsueh, Brian Chang Chi 19 January 2010 (has links)
This thesis addresses the problem of refocusing smeared SAR images caused by ionosphere phase scintillation noise. A SAR data is smeared when the received signal experiences phase irregularities due to platform orbit deviation, target movement, or, in this thesis, ionospheric scintillation noise due to trans-ionosphere propagation is analyzed. A SAR simulator is constructed to generate stripmap and spotlight data that satisfy theoretically predicted performances under ideal conditions. The simulator is incorporated with ionospheric phase scintillation models to analyze the broadening effect on system’s PSF. Degraded simulation spotlight data are used to test the proposed compensation algorithm. This thesis proposes a two-dimensional polynomial phase fitting algorithm to compensate scintillation noise. This work discusses some requirements of the scene in order to carry out the compensation and what is gained and lost in the process. A successful application of the proposed algorithm to TerraSAR-X data is also presented.

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