A method for the automatic calibration of an operational pas sive acoustic listening system

摘要

The calibration of a listening system during operation is achieved with regard to a clock synchronising of the listening stations included in the listening system, and the receiver characteristics of the microphones located in each listening station. These parameters are automatically adjusted by utilising a method for automatic calibration, using one or more sound generators to transmit special correction signals. The geographic position of each sound generator included in the calibration must be known to the listening system, and be within hearing distance and line of sight of the microphones in the listening system. The invention is a method for the correct calibration of a passive acoustic listening system while such a listening system is used for the determination of the direction to, or the position of the origin of sound signals. The automatic clock synchronising of listening stations is important for accurate determination of the direction to and/or the position of the origin of distinct sound. Long term stability and the accuracy of the listening system is secured by the clock calibration and the adjustment of the microphone characteristics. Microphone characteristics from the microphone producers can support the corrections. The calibration can be utilised for listening systems working in 2 or 3 geographical dimensions, and can be performed either continuous or periodic.