In order to successfully control the motion of a dynamic system,
one must be able to measure its motion, and form a set of equations
that model and formulate control inputs to the dynamic system. Since
the estimator and the system equations are only models of reality and
do not truly measure or represent the motion of the system, the
control laws selected to control the system must be robust enough to
converge and track to within the desired level of accuracy regardless
of these errors.

This chapter describes the physical models chosen to describe the
rotational dynamics of Ranger NBV, the methods of state estimation
employed to measure its motion, and the control laws selected to
guide it.