DEFINITION OF THE ANTARCTIC AND PYGMY BLUE WHALE CALL TEMPLATES. APPLICATION TO FAST AUTOMATIC DETECTION

• Main Authors: Samaran Flore, Olivier Adam, Jean-françois Motsch, Christophe Guinet
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; Indian; Southern Ocean; The Antarctic; Antarc*; Antarctique*; Blue whale
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.567.5394; http://www.cebc.cnrs.fr/publipdf/2008/SCA36.pdf

This paper deals with the automatic detection of low-frequency Antarctic (Balaenptera musculus interme-dia) and Pygmy (B. m. brevicauda) blue whale sounds produced in the Southwestern Indian Ocean. A new detection method based on a matched fi lter is introduced. Four original match templates are presented and tested against original blue whale subspecies calls. The mathematical formulas of these templates, defi ned by Gaussian curve models, are provided. The detection threshold is based on the correlation coeffi cients. The threshold was set to reduce false detections obtained on simulated signals at various signal-to-noise ratios. We focus our work on the true detections of whale calls. Moreover, to obtain a real-time system, we decrease the computational time by decimating the recorded signal (Fs=250Hz). We show that this new method enables us to effectively detect both subspecies in various ambient noises, in the Southern Ocean. RESUME Dans ce papier, les sons de basses fréquences émis par les baleines bleues Antarctique (Balaenoptera muscu-lus intermedia) et pygmées (B. m. brevicauda) dans le secteur sud – ouest de l’Océan Indien ont été détecté au-tomatiquement à partir d’une technique de fi ltrage adapté. Pour ce faire, des signaux synthétiques ont été créés à partir de signaux originaux en modélisant leurs équations mathématiques à partir de courbes gaussiennes.