Interpolation methods for vertical linear array element localization

Abstract

Array element localization is crucial for applications such as ocean acoustic tomography. Loss of navigation data makes it difficult to compensate for array motion when implementing operations such as mode filtering or beamforming. This paper presents a method for estimating missing array navigation data using an empirical orthogonal function (EOF) model. The method can be applied to estimate the location of some vertical array elements based on the location of the other elements. It assumes that second order statistics can be estimated from a set of navigation measurements for the full array. The paper applies the EOF-based method to estimate missing navigation data for the long range ocean acoustic propagation experiment (LOAPEX). The results are evaluated by examining how the errors in mooring motion estimation affect mode processing. In particular the paper analyzes the degradation in array gain and the errors in time of arrival for the low order modes. The error statistics indicate that use of the EOF method has a negligible effect on mode processing.