Various physical mechanisms that affect radiowave propagation at millimetre
wavelengths are considered. Current modelling weaknesses are highlighted and new
improved models or more appropriate modelling approaches are suggested.
Interference and resonance phenomena in the scattering of spherical ice and water
particles are reviewed. The long standing problem of the numerous resonances
observed in the scattering diagrams of dielectric spheres is answered.
The spatial structure and the physical characteristics of non-precipitable ice and water
clouds are reviewed. Extinction and back scattering calculations for a wide variety of
cloud models over the entire millimetre frequency spectrum are given. Multiple
scattering and the effects of super-large drops in clouds are also dealt with. The
potential of a spaceborne instrument in deducing information about the vertical
structure of various cloud types is examined. Attenuation and reflectivity profiles
resulting from various cloud types are calculated for a nadir pointing fixed beam
millimetre wave radar operating at 94 GHz.
The physics and application of the equation of radiative transfer to millimetre wave
propagation in the earth's atmosphere are given and also is the solution of this
equation for a typical millimetre wave remote sensing application. The theory of
gaseous absorption at millimetre wavelengths is presented and an improved modelling
approach is proposed for the calculation of the absorption and dispersion spectra of
atmospheric gases. The effects of trace gases on communication systems operating at
high altitudes are for the first time reported.
Finally the use of the 60 GHz oxygen absorption band for top-side air traffic
control/navigation and broadband transmission purposes is studied.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/4213 |
| Date | January 1993 |
| Creators | Papatsoris, Anastassios Dimitriou |
| Contributors | Watson, P.A. |
| Publisher | University of Bradford, Department of Electrical and Electronic Engineering |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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