The Sonic Boom Simulator of the Langley Research Center was used to quantify subjective loudness response to boom signatures consisting of: (1) simulator reproductions of booms recently recorded at White Sands Missile Range; (2) idealized N-waves; and (3) idealized booms having intermediate shocks. The booms with intermediate shocks represented signatures derived from CFD predictions. The recorded booms represented those generated by F15 and T38 aircraft flyovers and represented a variety of waveforms reflecting the effects of propagation through a turbulent atmosphere. These waveforms included the following shape categories: N-waves, peaked, rounded, and U-shaped. Results showed that Perceived Level and Zwicker Loudness Level were good estimators of the loudness of turbulence modified sonic booms. No significant differences were observed between loudness responses for the several shape categories when expressed in terms of Perceived Level. Thus, Perceived Level effectively accounted for waveform differences due to turbulence. Idealized booms with intermediate shocks, however, were rated as being approximately 2.7 dB(PL) less loud than the recorded signatures. This difference was not accounted for by PL. Sullivan, Brenda M. and Leatherwood, Jack D. Langley Research Center RTOP 537-03-21-03...

A study was conducted to measure and document the C-weighted day-night level (CDNL) of sonic booms due to air combat maneuver (ACM) training. Measurements took place in the Lava/Mesa airspace at the White Sands Missile Range, NM, where the primary ACM activity is F-15s from Holloman AFB. Thirty-five automatic sonic boom monitors (a combination of USAF BEAR and SBM-1 units) were deployed for a period of six months. All operations schedule and airspace clearance data were collected so that sonic booms could be correlated with specific events; A sample of air combat maneuver instrumentation (ACMI) tracking data was also collected. During the six-month measurement period, 4,600 ACM sorties were flown, 72% of which were F-15s. A total of 591 sonic boom events were recorded. For those missions for which ACMZ tracking data were obtained, sonic boom ray tracing calculations agreed well with the measured booms. The results were projected to planned supersonic operations at the Reserve, NM, and Valentine, TX, Military Operating Areas (MOAs) It was found that, at full capacity of 300 ACM sorties/month in each MOA, CDNL would be below 50 dB at all locations. Near the center of the supersonic area at Reserve, a sonic boom would be heard an average of once every three days. At Valentine, where supersonic operations will be divided between two areas, a sonic boom would be heard about once a week.