Development of a meteor radar wind measuring facility
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
This thesis details the development, construction and operation of a Doppler wind facility as an upgrade of the existing meteor radar, AMOR operated by the Department of Physics and Astronomy, Canterbury University, New Zealand. It also describes the initial interpretation of wind-field measurements so as to ascertain the potential for a more sustained survey. An overview of atmospheric dynamics is presented in order to provide a summary of wind motions accessible to meteor radar techniques. Tidal analysis methods applied to the data confirm a dominant semidiurnal tide with seasonally varying amplitude. The height resolution of the radar enables analysis of vertical structure, i.e., the semi diurnal tide's vertical wavelength. Echo analysis techniques which enable wind measurements with uncertainties < 3 ms-1 to be achieved from meteor echoes having duration times down to only 0.03 s are discussed. The method allows a line of sight wind measurement to be made from 90% of echoes. A transmitted beam which is narrow in azimuth combined with a dual interferometer and range determination locates the echo point within a 8 km3 3 dB box. Approximately 70% of the line of site wind measurements produce a spatially located horizontal wind speed. A method of reducing wind speed measurement errors introduced by the magnetic field is given which relies on both meridional and zonal components of the wind-field being measured. The AMOR winds data are compared with other wind measuring instruments that are geographically close and the results are discussed. Comparisons are also made with global model data. Analysis of the wind speeds as a function of ground range from the radar gives good evidence supporting the presence of gravity wave activity at meteor detection heights. A seasonal gravity wave dependence is also suspected.