Energy Spectral Density of the Sonic Boom

Abstract

The spectral density of the sonic-boom N-wave pressure time function is derived simply. The analysis method employed herein is one that avoids the usual method of integration by parts in computing the Fourier transform of any function made up of straight line segments such as an ideal N-wave pressure signature. The dominant first peaks of the normalized energy spectral density are plotted for different sonic-boom durations. The results modify those given earlier by Young [J. Acoust. Soc. Am. 40, 496–498 (L) (1966)].

Equivalent source model from acousto-optic measurements and application to an acoustic pulse characterization

“…At low frequencies, the spark source radiates little energy. This is due to the spark source energy spectral density nature [28] and it is related to the electrode gap width [29]. Moreover, the velocity output of the LDV is proportional to the time derivative of the acoustic pressure (Eq.…”