Time Dependence of Variances of Sonic Boom Waveform

IN a series of experiments1 performed in November and December 1966, at Edwards Air Force Base, California, sonic boom pressure signatures were recorded at forty-two ground level microphones, equally spaced in an 8,000 foot linear array, during level overflights of F-104 fighter aircraft at flight Mach numbers of approximately 1.3 and at an altitude of approximately 30,000 feet. The array was almost directly beneath the flight track. The variations in the signatures recorded by different microphones during the same overflight are believed to be caused primarily by atmospheric turbulence. This communication reports an analysis of the variations in these data and considers the extent to which the analysis substantiates a recent theory2.