One of the fundamental problems of sonar systems is the determination of the
bearings of underwater sources/targets. The classical solution to this problem,
the 'Conventional Beamformer', uses the outputs from the individual sensors of
an acoustic array to form a beam which is swept across the search sector. The
resolution of this method is limited by the beam width and narrowing this beam
to enhance the resolution may have some practical problems, especially in low
frequency sonar, because of the physical size of the array needed.
During the past two decades an enormous amount of work has been done to
develop new algorithms for resolution enhancements beyond that of the
Conventional Beamformer. However, most of these methods have been based
on computer simulations and very little has been published on the practical
implementation of these algorithms. One of the main reasons for this has been
the lack of hardware that can handle the relatively heavy computational load of
these algorithms. However, there have been great advances in semiconductor
and computer technologies in the last few years which have led to the availability
of more powerful computational and storage devices. These devices have
opened the door to the possibility of implementing these high-resolution Direction
Finding (DF) algorithms in real sonar systems.
The work presented in this thesis describes a practical implementation of some
of the high-resolution DF algorithms in a simple sonar system that has been
designed and built for this purpose. [Continues.
