Modal-MUSIC: A passive mode estimation algorithm for partially spanning arrays

Abstract

State-of-the-art mode estimation methods either utilize active source transmissions or rely on a full-spanning array to extract normal modes from noise radiated by a ship-of-opportunity. Modal-MUSIC, an adaptation of the MUSIC algorithm (best known for direction-of-arrival estimation), extracts normal modes from a moving source of unknown range recorded on a partially spanning vertical line array, given knowledge of the water column sound speed profile. The method is demonstrated on simulations, as well as on data from the SWellEx-96 experiment. Extracted normal modes from ship noise during the experiment are used to successfully localize a multitone source without any geoacoustic information.