Abstract by Francisco Irarrazabal
Physics and Astronomy
Initial characterization of the infrasound regime in a rocket acoustic field using the phase and amplitude gradient estimator method for acoustic intensity
Acoustic intensity measurements are used for the assessment of sound power level, which is applied in construction design, noise control engineering, aerospace industry, etc. The most common method used to measure acoustic intensity is the so-called “p-p method” or the traditional method. Since, the traditional method has limitations on acoustic intensity calculation, the phase and amplitude gradient estimator (PAGE) method for vector acoustic intensity has been developed and used previously to improve source characterization over broad frequency ranges. This paper describes initial applications of the PAGE method to the infrasound region of the acoustic field caused by a real rocket firing. The acoustic data is collected at several outdoor positions using multi-microphone probes. Measurement challenges include wind noise, which decreases SNR and coherence, low-frequency phase and amplitude mismatch between microphones, and determining an appropriate microphone spacing to maximize bandwidth. Analysis challenges include phase unwrapping and frequency resolution. This paper explains the treatment of these challenges and also show results.