Identification and localization of the sources of cyclostationary sound fields

A cyclostationary sound field is approximately regarded as a stationary sound field when analyzed by the traditional planar near-field acoustic holography (PNAH), which ignores the periodical time-variant property and makes it hard to reflect accurately the radiation characteristics based on the hologram results. In this article, a cyclostationary planar near-field acoustic holography (CPNAH) technique is proposed in which the cyclic spectral density (CSD) instead of the complex sound pressure is adopted as reconstructing physical quantity and the physical properties of CSD are utilized. And to avoid plenty of calculation and improve accuracy of extracting the cyclic property, pre-processing of holographic data, the method known as the gathering slices of CSD is also proposed. The experiment results demonstrate that the cyclic properties of cyclostationary sound fields can be extracted and the sources of cyclostationary sound fields can be exactly identified and localized by means of CPNAH.