waveguidethreemic.m

Three microphone directional wave separation algorithm for use in APR systems

This function uses recordings from three axially spaced microphones to separate the total pressure wave in a tubular acoustic system into its backwards and forwards traveling components, according to Kemp et. al*. The function is designed for use in discrete time Acoustic pulse reflectometry (APR) applications. The APR system comprises a speaker coupled to a source-tube that is instrumented with three axially spaced microphones.The function assumes that pressure waves present in the gas filled tube are 1D plane waves. Inputs to the system are the three column array of microphone recordings (pm) and the 6 column array of inter-microphone impulse response transfer functions (hmics). Outputs are the two three column arrays of directionally separated pressure waves at each microphone location (pmf, pmb).
* Kemp, J.; van Walstijn, M.; Campbell, D.; Chick, J. & Smith, R. Time domain wave separation using multiple microphones The Journal of the Acoustical Society of America, 2010, 128, 195