This project used VHF (Very High Frequency) meteor radars to investigate the couling and dynamics of the mesosphere and lower thermosphere at equatorial, middle and arctic latitudes. At equatorial latitudes studies investigated Kelvin waves, the Mesospheric Intra-Seasonal Oscillations, Mesospheric Quasi-Biennial Oscillation (MSQBO) and the non-linear coupling of tides and Kelvin waves. At middle latitudes the non-linear coupling of tides and planetary waves was investigated and at arctic latitudes studies investigated the structure of tidal oscillations.