System and method for monitoring wildlife

DETAILED DESCRIPTION This invention relates to a new and useful system and method for monitoring the presence of wildlife within a survey area.
More specifically this invention relates to a wildlife survey system that monitors the vocalizations emitted by wildlife targets so as to produce an indication of their locations within a survey area.
The system of this invention includes one or more sound receiving units.
Each sound receiving unit includes a parabolic reflector designed to capture the sound waves of the vocalizations produced by the wildlife target.
The sound receiving unit further includes at least three microphones.
A first one of the microphones is mounted in the center of the reflector so that it is located at the focal point of the reflector.
In one version of the invention, a second microphone is attached to the reflector to the left of the center microphone and a third microphone is attached to the reflector to the right of the center microphone.
The signals produced by the microphones are applied to an audio signal processing circuit that produces a set of subtractive signals representative of the differences in signal strength between the signals produced by the center microphone and the offset left and right microphones.
The subtractive signals are, in turn, used to generate an angular direction signal representative of the direction from which the vocalization originated.
The audio signal processing unit also produces a digital format signal representative of the frequency of the vocalizations monitored by the sound recording unit.
This signal is also supplied to the central processing unit.
When the system of this invention is used to perform a wildlife survey, the sound receiving unit monitors the vocalizations of the target animals.
Upon receiving the vocalization signals from the sound recording unit, the audio signal processing unit generates subtractive signals and the digitized vocalization signal.
Either the central processing unit or a separate digital signal processing circuit associated with the audio signal processing circuit then generates the angular direction signals for the received vocalizations