Dynamical input output systems are used for the description of technical or
physical systems. The internal states of such systems can often not be
measured. Thus, algorithms have to be implemented that estimate these
states. One of the most common instruments for this purpose is the design
of observers. An observer is a dynamical system which estimates the
internal states of the original system by using the input and output
signals of the original system.An important problem of observer design is
the transient behavior of the error to the original system. The main result
of the first part of this work is the design of an observer that at least
estimates the output of the original system in a prespecified way.The
second part deals with systems that have uncertain parameters. Among other
things the design of an adaptive observer will be used to design an output
feedback tracking control which will let the output signal of the uncertain
system converge to a prespecified output signal. Gaps in a proof of T.
Marino and P. Tomei will be filled and possibilities of extension as well
as simplification for the feedback control will be discussed.