Global infrasonic monitoring of large meteoroids

The hypersonic meteoroid/bolide–atmosphere interaction can generate numerous phenomena, including strong shocks and infrasonic waves. For a nonfragmenting bolide, the line source, blast wave radius, Ro, is the product of the Mach number and the body diameter. For bolides reaching continuum flow, Ro can range from ∼1 m to many kilometers. To be detected, Ro must exceed ∼10 m [at a minimum source energy, Es, of ∼4.10(7) J]. Beyond 10 Ro, a frequency equal to Cs/(2.81 Ro) will be generated which will change during propagation due to effects of nonlinearity, absorption, and dispersion. Infrasonic arrays are now being routinely used to detect and locate such large near‐Earth objects. Data from the CTBT IMS monitoring system will help refine estimates of the large body influx rate. These arrays have baselines of ∼1 to 2 km using microbarometers with response from ∼10 to 0.01 Hz. For ranges from 100 to 14<th>000 km, such bolides have been observed previously with amplitudes from 0.02 to 16 Pa, with periods from 0.50 to 300 s, with total durations from 0.10 to 25 min and with computed acoustic efficiencies varying from 0.01% to ∼10%. The influx rate will be discussed as well as several recent bolides detected by Los Alamos arrays and by US DoD satellites.