Um estudo sobre o uso de interferometria acústica aplicada à caracterização do ruído de banda larga de navios

Abstract

Interferometry caused by overlapping sound waves is used mostly in underwater acoustics for estimating environmental parameters (geoacoustics, oceanographic and others). This work is a study about the use of acoustic interferometry applied to broadband ship-radiated noise characterization. This study is based in acoustic measurements of the ship-radiated noise at Cabo Frio Island region - Arraial do Cabo - RJ (Brazil). To understand the characteristics of interference patterns found in the measurements, simulations were performed using propagation models based on ray tracing and normal modes theory. According to the simulation results, the interference patterns are strongly influenced by the first arrivals of the signal. These arrivals are related to rays having a larger incident angle than the critical angle, i.e., these arrivals are connected to the propagating modes.