Abstract by Francisco Irarrazabal
Physics and Astronomy
Infrasonic microphone calibration project
This work describes the phase and amplitude correction of 12.7 mm diameter, Type-1 microphones in the infrasound region using measured noise field of a large rocket motor. The data stem from acoustic intensity measurements using two-dimensional, four-microphone probe. Althought the calibration processing is well-known, obtaining the necessary transfer functions in the infrasound regime is challenging because signal-to-noise ratio are often low, large recordings are required, and microphones mismatch are significantly variable across these low frequencies. Far-field measurements of a large static rocket test provide the enough energy to perform the calibration. The performance of the calibration method, including limitations, for different microphones responses and probe configurations is presented.