\beforepreface

\prefacesection{Abstract}

\input abstract

\prefacesection{Acknowledgements}

During my four years in Princeton I had the opportunity to
meet many people whose relationship I enjoyed and
who made my stay here more than just an intellectual experience.
First, I wish to thank my advisor Prof. S. Y. Kung, whose constant
support, encouragement and valuable guidance
I was fortunate enough to receive in all these years.
I learned from him much more than I can confess in these few lines.
I also wish to thank Prof. B. Liu and Prof. S. Kulkarni
for diligently reading my thesis and making valuable comments
for the improvement of the script. In addition, Prof. Kulkarni's
lengthy discussions with me regarding Chapter \ref{ch:Motion}
helped significantly improve the quality of the results.

I should also mention the many stimulating discussions with
Prof. H. V. Poor who suggested that I look at the drifting sinusoids
detection problem as a potential application of my newly proposed techniques.
Without his very important input, Chapter \ref{ch:Applications}
would have been a lot poorer. Among my many
colleagues and friends in Princeton
I wish to single out Dr. J. Vlontzos whose
help included much more than just teaching me \LaTeX~and
Dr. D. Geiger, who introduced me to the motion
estimation problem. In addition
I wish to thank Mr. J-S Taur and Mr. W-H Chou
for many interesting discussions and
Ms. S. Gafgen who often thought that she was giving me
hard time while it was usually me who was pushing the limits.

Last but certainly not least I wish to thank my wife Anthoula
whose love and support kept me going during these years,
and my parents Yannis and Dimitra, without whom none of this
would have been possible.


\afterpreface
