Use of Low-Cost Microphones for Acoustic Measurement of High-Powered Amateur Rockets

The payload environment of a rocket is random and dynamic during liftoff and flight, with acoustic noise, vibration, and acceleration falling under its definition. Characterization of this environment is important to finalize payload design requirements and insure mission completion. This report will focus on the study and measurement of acoustic noise using a low-cost microphone. Various spectral analysis techniques were utilized to characterize acoustic intensities and frequency content. Effects of vibration and acceleration, ground reflection, atmospheric absorption, and nonlinear propagation were investigated. Noise data were obtained from a rocket launch and several vertical, staticired hybrid motors. The propulsion system acoustic loads were compared to prediction methods from NASA SP-8072