Azimuth-elevation direction finding, using one fourcomponent acoustic vector-sensor spread spatially along a straight line

An acoustic vector-sensor (a.k.a. a vector hydrophone for underwater applications) comprises one pressuresensor plus three uniaxial velocity-sensors which are orthogonally oriented with regard to one other. Song &Wong [8] has analyzed how these four components can be placed arbitrarily in space to extend the threedimensional array aperture, yet estimating a far-field incident acoustic emitter's azimuth-elevation directionof-arrival. This work will focus on the particular array geometry whereby the four components are aligned on a straight line in three-dimensional space. This work will show how to estimate a far-field emitter's azimuthelevation direction-of-arrival unambiguously, despite the four components' spatial separation, despite these separations' arbitrariness and sparseness.