Field Trials of Geophones as Arctic Acoustic Sensors

This paper considers two practical issues concerning the use of ice-mounted geophones as Arctic acoustic sensors: the ability to resolve the relative bearing to an acoustic source in the water column, and the ability to determine absolute sensor bearing via short baseline GPS. Two approaches to bearing estimation are compared, including beamforming seismo-acoustic arrivals at an array of geophones and resolving the incident power versus arrival angle at a tri-axial geophone. The latter approach is preferable logistically, as it requires only a single sensor. However, due to the complexities of seismo-acoustic propagation in Arctic pack ice, it is difficult to predict a priori the effectiveness of these approaches, and source-bearing estimation must be studied in situ via Arctic field trials.