C-4 EXPLOSION CHARACTERIZATION AND COMMON TRANSDUCER ANALYSIS THROUGH APPLICATION OF DIGITAL CORRECTIONS FOR CONDENSER MICROPHONES

Open Access
Author:
Burkhalter, Paul Stephen
Graduate Program:
Acoustics
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
July 08, 2008
Committee Members:
  • Victor Ward Sparrow, Thesis Advisor
  • Thomas B Gabrielson, Thesis Advisor
Keywords:
  • Digital Microphone Corrections
  • C-4
Abstract:
Composition C-4, a common explosive, produces a broad range of frequencies when detonated. C-4 is used in community-annoyance studies by the United States Army Corps of Engineers (USACE) to simulate the discharge of tank and assault-vehicle cannons. Standard measurement microphones, however, do not accurately capture all of the frequencies produced by these explosions. Consequently, the USACE Construction Engineering Research Laboratory (CERL) asked Penn State to provide a set of digital correction algorithms for these microphones that would artificially extend the usable bandwidth. They also requested a demonstration of these corrections applied to C-4 explosion data in support of their work on community annoyance near training and test and evaluation sites. A field test was arranged at the Aberdeen Proving Grounds in Maryland to set up equipment and record several explosions. In this paper, the set up and recording at Aberdeen is described; the correcting algorithms are explained; and the measured and corrected data is analyzed. The analysis includes rise times, peak pressures, energy spectral densities, waveform plots, and the effects of sensor baffles. Limitations of the instrumentation are also discussed and recommendations for microphone types and orientations are made.