The Effect of Relative Speed of Moving Noise Sources on the Moving Frame Acoustic Holography

Abstract

Moving frame acoustic holography (MFAH) enables us to visualize the noise generated by moving noise sources by using a line array of microphones affixed to the ground. The method uses the relative coordinate transformation that relates the sound pressure on the measurement and the hologram coordinate. However, the transformation is valid only when a moving line array of microphone measures the sound field of a non-moving noise source. If a line array of microphones affixed to the ground measures the sound of a moving noise source, this transformation produces errors on the hologram. This is a nontrivial drawback of MFAH. This paper studies these errors theoretically and proposes a correction method.