The Canterbury University ST atmospheric radar development: design and feasibility (1998)
AuthorsDunford, Adam J.show all
This thesis describes the design of several components of a proposed VHF radar system for the Department of Physics and Astronomy of the University of Canterbury, New Zealand. A suite of software for implementing the full correlation analysis (FCA) of Briggs  has been developed and its operation tested using data from the MU radar of the University of Kyoto. An examination of the spatiotemporal variation in signal power of the MU data revealed two distinct features. The first, short duration regions of high power were considered to be aircraft flying above the radar. The second structures observed were thin horizontal layers of low reflected power. Profiles of potential refractive index squared were calculated from radiosonde data and these showed good agreement with profiles of reflected echo power. The FCA velocities are shown to be dependant on both triangle size and FCA algorithm. Failure to exclude the zero-lag covariance datum led to larger velocity differences between different receiving triangles in agreement with the modelling results of Holdsworth and Reid . Comparison of the FCA algorithms of Briggs  and Brown and Chapman  (B&C) show that the B&C method gives both smaller velocities and larger variances than the Briggs method. Comparisons are presented between FCA and DBS velocities on both 10 and 50 minute timescales and these show good agreement. FCA momentum fluxes are obtained by combining the FCA winds with vertical winds and these were compared with momentum fluxes calculated using the symmetric-beam method of Vincent and Reid  and the 'five-beam' method of Worthington and Thomas . On the short timescales available here the FCA method showed only moderate agreement with the two DBS techniques, which had good agreement with each other. The operation of the radar controller and integrating A/D converter hardware designed for the Canterbury radar is discussed and a procedure is described for measuring the pointing angle of the transmitting array using cosmic radio sources. Finally, modifications to the transmitting array are described to allow the radar to measure winds using a multi-beam method similar to Doppler beam-swinging thus providing an alternative to the spaced antenna mode of operation.