Sökning: "aperture"
Visar resultat 21 - 25 av 198 avhandlingar innehållade ordet aperture.
21. Ultrawideband-Ultrawidebeam Synthetic Aperture Radar – Signal Processing and Applications
Sammanfattning : This dissertation presents practical issues in Ultrawideband – Ultrawidebeam (UWB) Synthetic Aperture Radar (SAR) signal processing and crucial applications developed on UWB SAR. In the context of this dissertation, UWB SAR refers to the SAR systems utilizing large fractional bandwidth signals and synthesizing long apertures associated with wide antenna beamwidths. LÄS MER
22. Practical Consideration on Ultrawideband Synthetic Aperture Radar Data Processing
Sammanfattning : The practical considerations in ultrawideband (UWB) synthetic aperture radar (SAR) data processing in general and UWB SAR imaging in particular are clarified and presented in detail in this thesis. They are imaging algorithm, impulse response function in SAR imaging (IRF-SAR), apodization, RF interference (RFI) and SAR image quality measurement. LÄS MER
23. Synthetic-Aperture Radar Imaging of Forests in the VHF and UHF Bands: Electromagnetic Models and Data Analysis
Sammanfattning : Synthetic-aperture radar (SAR) is a technique which can image the Earth’s surface, from a spaceborne or airborne platform, irrespective of daylight or cloud cover. During the last decades there has been an increasing interest in using SAR for estimation of forest parameters. LÄS MER
24. The Impact of Fracture Geometry on the Hydromechanical Behaviour of Crystalline Rock
Sammanfattning : Effective construction of tunnels in fractured crystalline rock requires a unified approach for handling rock mechanics and hydrogeological issues. Traditionally, rock mechanics and hydrogeology not only use different nomenclature, they also measure parameters such as e.g. aperture differently. LÄS MER
25. Quasi-Single Mode VCSELs for Longer-Reach Optical Interconnects
Sammanfattning : The vertical-cavity surface-emitting laser (VCSEL) is the standard light source in optical interconnects connecting racks in supercomputers and datacenters hosting services such as online data sharing, storage and processing. VCSELs have numerous advantages such as low power consumption, fast direct modulation at low currents, circular output beam for efficient fiber coupling and low-cost fabrication. LÄS MER