Improvement in outdoor sound source detection using a quadrotor-embedded microphone array

This paper addresses sound source detection in an outdoor environment using a quadrotor with a microphone array. Since the previously reported method has a high computational cost, we proposed a sound source detection algorithm called MUltiple SIgnal Classification based on incremental Generalized Singular Value Decomposition (iGSVD-MUSIC), which detects sound source location and temporal activity with low computational cost. In addition, to relax an over-esitimation problem of noise correlation matrix which is used in iGSVD-MUSIC, we proposed Correlation Matrix Scaling (CMS), which realizes soft whitening of noise. The protptype system based on the proposed methods were evaluated with two types of microphone arrays in an outdoor environment. Experimental results showed that the combination of iGSVD-MUSIC and CMS improves sound source detection performance drastically and achieves real-time processing.