LAUNCH NOISE DISTRIBUTION OF NIKE-ZEUS MISSILES

Abstract : Maximum sound pressure levels averaging 115 decibels, with extreme values of 90 and 128 decibels, were measured about one mile behind the Nike Zeus Missile Launcher for the variety of meteorological conditions occurring during four monthly tests.Additional small samples of data taken both near the launcher and at two miles distnce from the sound source suggest a 20-decibel decline in peak noise level per mile. The decay of the noise level following peak was between two and three decibels per second for the first ten seconds. A frequency analysis of the sound level measured at launch indicates that frequencies below 125 cps are predominant. Under mos meteorological conditions, the sound pressure levels at one mile behind the launcher would not be great enough to cause any structural damage or personnel injury. The levels would be above 90 decibels however, which approach the level at which complaints of annoyance become frequent. (Author)