Kaiser, Alan Bernard2011-08-252022-10-302011-08-252022-10-3019671967https://ir.wgtn.ac.nz/handle/123456789/25932Techniques involving spherical coordinate transformations are used to analyse two types of radio propagation path: (1) The sunrise interference patterns observed on long VLF propagation paths are analysed to reveal the latitude variation of VLF propagation parameters. In addition, a new model of modal interference is proposed to explain certain anomalous observations during the first part of the sunrise transition. (2) Transitions in the scintillation of satellite VHF signals are triangulated from three New Zealand stations. This triangulation yields the morphology of sharp boundaries to a subauroral region of ionospheric irregularities.pdfen-NZText