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Title: The propagation of VHF and UHF radio signals in the State of Qatar
Author: Al-Rasheed, A.-R.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1995
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Whereas the State of Qatar has a very flat and almost completely desert terrain, and to a large extent is surrounded by shallow warm sea, observed VHF and UHF radio signals exhibit far from flat and uniform signal level characteristics. This thesis describes a step by step plan, and series of signal observations, in order to be able to clarify the signal conditions that can be expected for many mobile radio operations in Qatar. The results fall into four distinct categories: (i) the long, beyond radio line-of-sight, desert radio path; (ii) regular long distant overland tropospheric ducted propagation; (iii) irregular propagation within and around the capital city; and (iv) irregular off-shore signals due to super-refraction. The first category is interesting because it ties in closely with the well studied theoretical model for radio wave propagation round a smooth earth and marginal variations between VHF and UHF signals in the diffraction (shadow) region of propagation. At night, very regular super-refracted propagation is recorded and can be related to the meteorological conditions observed over the State. Much more irregular signal coverage is discovered around the main city of Doha, where both metallic artifacts such as towers and pylons act as scatterers of the signals, as do the several re-inforced concrete buildings. To add to the signal coverage problem, the night-time super-refraction problem is also present. Observations of off-shore super-refracted signals from other countries in the Gulf area were also regularly recorded over a one-year period, but their occurrence does not fit the regular pattern observed within the State.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available