| Measurements of the variations of OH intensities have been recorded by a three station network of scanning radiometers in Southwestern Ontario. Two scanning radiometers were assembled and installed at Elginfield Observatory and at St. Joachim, Ontario to join the existing radiometer at Delaware Observatory. Each radiometer performs a 16 by 16 point raster scan of the night sky every minute, turning itself on and off when the solar depression angle is less than six degrees.; The horizontal phase velocity, horizontal wavelength, and frequency of the internal gravity waves are derived from the OH intensity measurements using time frequency analysis techniques, including the S-Transform (ST), Localized Cross Spectral Analysis (LCSA), and Generalized Instantaneous Frequency (GIF).; The ensemble of gravity waves seen in all three instruments are analyzed, and observed to have a strong dependance in their propagation direction with the majority of waves seen at each of the three sites having a horizontal wavevector in the northeast direction. The most common parameters observed are: horizontal phase speed = 45 m/s, horizontal wavelength = 25 km, period = 10 minutes.; The observations are compared to a model of the atmospheric transmission of upwardly propagating gravity waves. Examination of the model indicates that the tidal components of the horizontal winds (taken from the HWM-96 model) are important factors in determining which upwardly propagating gravity waves reach the OH airglow. |
