Long Range Location of Wildlife Using Phased Arrays of Microphones: A Feasibility Study

摘要

Location of animals such as birds by listening to their calls or songs can significantly reduce the stress on both animal and researcher, when compared to more traditional methods such as affixing radio transmitters or "pushing bush". Previous methods of acoustic location of wildlife have utilized a large number of individual microphones, which together locate the sound by differential time of arrival or other methods. However, in a dense rain forest, the distance sound travels through the underbrush is very short, meaning a fine grid of microphones must be placed, often in treacherous terrain. This paper presents an alternative method, using a small number of steerable, phased arrays of microphones to detect and locate a sound source over a much longer range than would be possible with a grid of individual microphones. A simulation study compares the two methods. The motivation for this work is a preservation of the kokako, an endangered species of bird with a number of very small ranges in New Zealand.