Calibration of a distorted towed array using a propagation operator

Abstract

In this paper, a new method for array shape calibration is presented. This method can be applied to any antenna distortion, it does not require any a priori knowledge about the sources, and it is relatively simple to implement. A number of unknown remote point sources, propagating plane waves, are required to implement this method. An equal number of sensors having known relative positions are used as a geometric reference. The method relies on a propagation operator, called the propagator, which can be estimated from the cross spectral matrix of the received signals through a simple least-square process. The performances of the proposed method are illustrated through simulations by showing how good accuracy in source bearing estimation, by both the classical beamforming method and MUSIC, can be recovered when the array shape is estimated.