Publications

Public concern regarding the effects of noise generated by the detonation of excess and obsolete explosive munitions at U.S. Army demolition ranges is a continuing issue for the Army's demilitarization and disposal groups. Recent concerns of citizens living near the McAlester Army Ammunition Plant (MCAAP) in Oklahoma have lead the U.S. Army Defense Ammunition Center (DAC) to conduct a demonstration and evaluation of noise abatement techniques that could be applied to the MCAAP demolition range. With the support of the DAC, MCAAP, and Sandia National Laboratories (SNL), three types of noise abatement techniques were applied: aqueous foams, overburden (using combinations of sand beds and dirt coverings), and rubber or steel blast mats. Eight test configurations were studied and twenty-four experiments were conducted on the MCAAP demolition range in July of 2000. Instrumentation and data acquisition systems were fielded for the collection of near-field blast pressures, far-field acoustic pressures, plant boundary seismic signals, and demolition range meteorological conditions. The resulting data has been analyzed and reported, and a ranking of each technique's effects has been provided to the DAC.

An important application of seismic and acoustic unattended ground sensors (UGS) is the estimation of the three dimensional position of an emitting target. Seismic and acoustic data derived from UGS systems provide the taw information to determine these locations, but can be processed and analyzed in a number of ways using varying amounts of auxiliary information. Processing methods to improve arrival time picking for continuous wave sources and methods for determining and defining the seismic velocity model are the primary variables affecting the localization accuracy. Results using field data collected from an underground facility have shown that using an iterative time picking technique significantly improves the accuracy of the resulting derived target location. Other processing techniques show little advantage over simple crosscorrelation along in terms of accuracy, but may improve the ease with which time picks can be made. An average velocity model found through passive listening or a velocity model determined from a calibration source near the target source both result in similar location accuracies, although the use of station correction severely increases the location error.