From 1988 to 1993 13 sonic booms of space shuttles approaching Edwards Air Force Base were measured at a site 10 miles west of EAFB, with one to seven different sound level meters for each measurement. Results from five of these measurements are here presented. Maximum differences in measured levels between instruments for the same flight varied from 0 to 6 dB depending on the measurement descriptor and model of sound level meter. The average difference between predicted and measured values was 0.7 ± 1.5 dB. for sound level meters with adequate bandwidth the waveforms measured varied from a near perfect N-wave to a more distorted form reflecting the influence of the varying condition of the atmosphere during propagation to the ground.
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