Cumulant-Based Coherent Signal Subspace Method for Bearing and Range Estimation

Zineb Saidi,Salah Bourennane

doi:10.1155/2007/84576

Abstract

A new method for simultaneous range and bearing estimation for buried objects in the presence of an unknown Gaussian noise is proposed. This method uses the MUSIC algorithm with noise subspace estimated by using the slice fourth-order cumulant matrix of the received data. The higher-order statistics aim at the removal of the additive unknown Gaussian noise. The bilinear focusing operator is used to decorrelate the received signals and to estimate the coherent signal subspace. A new source steering vector is proposed including the acoustic scattering model at each sensor. Range and bearing of the objects at each sensor are expressed as a function of those at the first sensor. This leads to the improvement of object localization anywhere, in the near-field or in the far-field zone of the sensor array. Finally, the performances of the proposed method are validated on data recorded during experiments in a water tank.

Highlights

Noninvasive range and bearing estimation of buried objects, in the underwater acoustic environment, has received considerable attention.Many studies have been recently developed
We have extended firstly the MUSIC method [18] to estimate simultaneously range and bearing of the objects using narrowband signals by including the acoustic scattering model of the objects
We proposed a new method to estimate both bearing and range of the sources in a noisy environment and in presence of correlated signals

Summary

Introduction

Noninvasive range and bearing estimation of buried objects, in the underwater acoustic environment, has received considerable attention.Many studies have been recently developed. Guillermin et al [2] use the inversion of measured scattered acoustical waves to image buried object, but the applicability in a real environment is not proven. Another method which uses a low-frequency synthetic aperture sonar (SAS) has been recently applied on partially and shallowly buried cylinders in a sandy seabed [3]. Other techniques based on signal processing, such as time-reversal method [4], have been developed for object detection and localization but their applicability in real life has been proven only on cylinders oriented in certain ways and point scatterers [5]. Having techniques that operate well for simultaneous range and bearing estimation using wideband and fully correlated signals scattered from near-field and far-field objects, in a noisy environment, remains a challenging problem

Methods

Results

Conclusion