Shallow ambient noise variability due to distant shipping noise and tide

摘要

Study and characterization of distant shipping component of ambient noise in shallow water aid i: design of passive surveillance algorithms and effective signature analysis of marine vessels. This lette presents the work carried out on real ambient noise recording in very shallow water condition close t a commercial port with heavy shipping activity to study and characterize the distant shipping noise com ponent for variations due to tide. Ambient noise recording was carried out by a bottom mounted sensor a 30 m depth at regular interval for a period of over one month and the spectrum in the band 10-1.6 kH was characterized for its diurnal spectral variation. The study concluded that the distant shipping nois component due to heavy small vessel activity in the nearby port resulted in up to 35 dB variation in th shallow water ambient noise in coastal areas that may have serious implication on passive surveillanc algorithms performance in the vicinity if adequately not addressed. This is the first such effort in ambien noise measurement and characterization in the extremely shallow water channel condition prevalent i the tropical waters off the west coast of India.