Long-range acoustic detection and localization of blue whale calls in the northeast Pacific Ocean

Analysis of acoustic signals recorded from the U.S. Navy's SOund SUrveillan ce System (SOSUS) was used to detect and locate blue whale (Balaenoptera mu sculus) calls offshore in the northeast Pacific. The long, low-frequency co mponents of these calls are characteristic of calls recorded in the presenc e of blue whales elsewhere in the world. Mean values for frequency and time characteristics from field-recorded blue whale calls were used to develop a simple matched filter for detecting such calls in noisy time series. The matched filter was applied to signals from three different SOSUS arrays off the coast of the Pacific Northwest to detect and associate individual call s from the same animal on the different arrays. A U.S. Navy maritime patrol aircraft was directed to an area where blue whale calls had been detected on SOSUS using these methods, and the presence of a vocalizing blue whale w as confirmed at the site with field recordings from sonobuoys. [S0001-4966( 98)01312-5].