ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-03102014-092925


Tipo di tesi
Tesi di dottorato di ricerca
Autore
TOMEI, SONIA
URN
etd-03102014-092925
Titolo
Propagation Effects on HF Skywave MIMO Radar
Settore scientifico disciplinare
ING-INF/03
Corso di studi
INGEGNERIA
Relatori
tutor Prof. Martorella, Marco
relatore Prof. Berizzi, Fabrizio
relatore Prof. Coleman, Christopher John
Parole chiave
  • ionospheric propagation
  • HF radar
  • HF MIMO radar
  • MIMO radar
  • TIDs
Data inizio appello
27/05/2014
Consultabilità
Completa
Riassunto
MIMO technology has been suggested as an effective tool to overcome some of the issues typical of conventional OTH skywave radars. The advantages of the application of MIMO technology to HF Skywave radars is based on the transmission of multiple linearly independent waveforms and their separation at the receiver. Notwithstanding, the high instability of the ionosphere is responsible for severe signal fading and degradation that can prevent the separation with consequences on the radar performance.
The present thesis is concerned with the problem of the effects of ionospheric propagation, which are analyzed from a theoretical point of view at first, through the description of the ionosphere morphology and the disturbances that affect the ionospheric electron density structure. The relation between structural variations in the ionosphere and the transmitted signal parameters has been then derived. A radar signal simulator has been realized accordingly to the signal model proposed in the thesis. The results of the thesis concern three different aspects of propagation in HF MIMO radars. The orthogonality of the transmitted waveforms after ionospheric propagation is analyzed first, while the effects of ionospheric propagation on the results of conventional beamforming is studied secondly. The performance of the radar receiver are evaluated in terms of ROCs in case of multipath propagation and compared to the single path case.
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