\section{Sensors}

	\subsection{Barometer}
		As stated by \cite{ipin2015} \todo{and the other paper directly}, ambient pressure readings are highly influenced
		by environmental conditions like the weather, time-of-day and others. Thus, relative pressure readings are
		preferred over absolute ones. However, due to noisy sensors \todo{cite oder grafik? je nach platz}, one
		single reading is not enough as a relative base. Harnessing the usual setup time of a navigation-system (
		route calculation, user checking the route) we use the average of all barometer readings during this
		timeframe as realtive base $\overline{\mPressure}$.
		
		
	\subsection{Wi-Fi \& iBeacons}
	
	\subsection{Step- \& Turn-Detection}