A theoretical treatment of the long range propagation of impulsive signals under strongly ducted nocturnal conditions.
On clear nights, over flat land, a sound duct develops in which sound can carry to great distances. As is the case with all ducted propagation, there is strong dispersion so that a broadband signal undergoes severe distortion as it propagates. The signal received at long ranges from an impulsive source is a wave train, of much greater duration than the initial impulse, consisting of a series of arrivals. The long range ground to ground propagation of an impulsive signal in a typical nocturnal duct is studied and the natures of the various arrivals are explained. A direct connection is drawn between the meteorological and ground conditions and the structure of the propagated signal.
Waxler
Roger
R
National Center for Physical Acoustics, University of Mississippi, University, Mississippi 38677, USA. rwax@olemiss.edu
Gilbert
Kenneth E
KE
Talmadge
Carrick
C
D000162:Acoustics; D002940:Circadian Rhythm; D002980:Climate; D005843:Geography; D008962:Models, Theoretical; D015398:Signal Transduction; D013997:Time Factors