The adaptation of Imaging Doppler Interferometry (IDI) to the dynasonde deployed at the Bear Lake Observatory (41.9 ¿N, 111.4 ¿W) in northeastern Utah enables the routine measurement of mesospheric dynamics. Influenced by the direction of the prevailing wind, a clear seasonal variation is seen in the mesospheric echo numbers. The technique also provides a monitor for the amplitude of the main tidal modes as well as for studying planetary waves with periods of several days. The observations are found to be consistent with those from different instruments based at the same site thus confirming the IDI characterization of the mesospheric wind field. ¿ 2001 American Geophysical Union