A calibration methodology for an acoustical array

A simple "ad hoc" method that allows the calibration of both sensor arrays, in transmission and in reception, for narrow-band acoustic radar systems using beamforming techniques is presented in this paper. This system uses low cost sensors and amplifiers, and for them there are not calibration data of phase and gain characteristics. Using a reference sensor system, auto-calibration procedures for a transmission array and for a reception array have been implemented. Finally, the proposed methodology has been tested on a real system, based on a uniform linear array with 15 lambda/2-equispaced sensors. The degradation that is introduced on beampatterns with and without compensation for several steering angles has been analysed. This methodology can be extrapolated to 2D arrays.