Amplitude, phase and phase centre model performance for antennas used in land and satellite based positioning systems

Antenna performance in various radio positioning system applications is considered. The antennas used in these systems are modelled for amplitude and phase response and phase centre movement. A complete formulation for the location of the antenna phase centre is reviewed and a technique to determine the antenna phase centre location from measured phase observations is developed.;This work also presents, for the first time, the phase and phase centre properties of several classes of antennas used in both UHF and GPS positioning systems.;Both theoretical and measured results are presented for antennas used in UHF radio positioning systems and several antenna designs are presented that will reduce the system errors due to the antenna properties.;Theoretical models are developed for antennas used in GPS positioning and the antenna design parameters are varied to show their effect on antenna amplitude, phase and phase centre performance.;The effects of the antenna phase and phase centre properties on range determination in both UHF positioning systems and the Global Positioning System (GPS) have become an important concern for the users of these systems. For the first time in the literature this work presents a decription of how these antenna properties affect the range determination for both phase and time based positioning systems.