Joint microbarograph and radar observations of a meteor Free

On the night of 13–14 December 1974, joint observations were made at Springhill Meteor Observatory using both meteor radar and a specifically designed array of microbarographs. At about 5 a.m. local time (near the peak of the Geminid meteor shower), a relatively large meteor was recorded on two radars followed about 14 min later by the arrival of infrasonic pressure waves at all four sensors. The signal is not a simple N wave, but contains at least three well‐defined cycles (with an overall dominant frequency ∼2 Hz, a peak‐to‐peak amplitude of ∼6 μ and a total duration of ∼9 sec). Not only is the time delay appropriate (corresponding to an acoustic signal velocity of ∼300 m/sec), but estimates of meteor mass (∼1 kg) made using the radar echo theory of McIntosh and the line source blast wave theory of ReVelle are in good agreement. Unfortunately, due to overcast conditions at the time, photographic data were not available for this event. Additional recordings are currently being made with the Springhill system and a second microbarograph array is being installed on the Canadian Prairies to be operated in conjunction with the camera network of the Meteorite Observation and Recovery Project.