A meteor infrasound recording system

The National Research Council of Canada has established an infrasonic microphone array near Saskatoon, Saskatchewan, to detect acoustic waves generated by large meteors during their entry into the atmosphere. The system consists of four ceramic microphones modified for an extended low-frequency response and fitted with noise-reducing pipes, and involves the sending of FM signals over telephone lines to a local telemetry station, followed by digital data transmission to a recording centre. A microprocessor is used for data-handling and magnetic tape control. The system has a peak sensitivity at 0.1 Hz, a full-scale range ± 15 microbar, and a resolution of 0.125 microbar.