\item what are the limits that the sensor dynamics poses. (i)initial delay, (ii) delay when position is requested unless always on, (iii) periodical drain of battery for updating ephemeris data, (iv) you can se you have lost visibility only if you are turned on ,(v) the best you can do is turn off the antenna (for this reaosn as soon as we get the position we assume you want to turn off the antenna)
\item what are the phenomena we have to account for in regular ``working'' conditions. cycling on two different periods. plot of how this looks like?
\item what are the possible disturbances we have to deal with. expiration of ephemeris data and loss of visibility. examples?
\item how do we do this? state machine of the controller. three kind of transitions: some are observed events, some are control actions, some are both
\item how do we do this? state machine of the controller`/ref{fig:controller}. three kind of transitions: some are observed events, some are control actions, some are both
