Parametric Study of Equivalent Source Modelling with Monopole Clusters

Sammanfattning

Master students at KTH have created a method, Dual-LP, to estimate real-life sound fields as clusters of monopoles. So far, the method has shown potential in source localization - but it requires further testing to investigate how it is ideally performed and what outcomes to expect. Dual-LP is classified as an inverse method, and it is inspired by phased arrays. The probes, or numerical microphones, were positioned in a multi-armed logarithmic spiral. The purpose of this thesis project was to optimize the geometrical parameters of the spiral array and minimize probe population. Dual-LP was, in this case, tested in a simulation including a train with two carriages. Sensitivity analyses were performed, and the geometrical parameters were systematically varied through six sub-tests. Results were interpreted as a larger number of probes did not necessarily equal a more favorable outcome. Several interpretations of the tests were possible, and information about the parameters’ significance was obtained. For example, a low amount of probes per arm did not negatively affect the output as much as the number of arms did. Dual-LP could still be considered to be in its early days, and there is a large amount of possible future work to be considered to further optimize sound reconstruction.