result section sketch

paper/sections/06-results.tex

+\subsection{GPS sensor dynamics}
+\label{sec:res:gps}
+
+First-principle analysis of GPS dynamics: \emph{time to first
+  fix}. Comparison with empirical analysis from the state of the art
+(check that numbers match the python-nokia implementation or whatever
+else is available). Implementation issues with existing solutions
+(there are some unjustified delays -- probably introduced by the
+software and software bugs -- that could be eliminated).
+
+Additionally, decribe \emph{phenomena} like loss of ephemeris and
+randing data and what are the delays introduced because of that. Say
+that losing the ephemeris data means basically having the GPS receiver
+turned off for ``too long'' and losing the ranging data is mostly
+equivalent to a worst case in losing visibility of the satellites. If
+you want to distinguish, you can have a finite state machine for each
+satellite.
+
+\subsection{Power Consumption Accuracy Trade Off}
+\label{sec:res:tradeoff}
+
+In this section, we use real traces from an IMU sensor and a GPS
+receiver in two different conditions: car, and bicycle. In both cases,
+we recorded measurements for the entire duration of the trace with
+both devices. We show the accuracy of the IMU, compared to the GPS
+trace (which the sensor fusion algorithm considers to be the ground
+truth). We expose the trade off between power consumption due to the
+GPS antenna being turned on and accuracy in both cases. Expectation:
+in the bike trace, the IMU sensor trace is more noisy.
+
+Figures (both bike and car) with the accuracy ``areas''.
+
+\subsection{Simulation of Ranging Data Loss}
+\label{sec:res:vis}
+
+Simulation of what happens if ``lose visibility'' transition is taken
+from time to time on one of the two traces above.
+
+\subsection{Simulation Results}
+\label{sec:res:sim}
+
+Montecarlo simulations. Characteristics:
+\begin{itemize}
+\item We generate 10000 traces, 60 minutes long.
+\item For each point in each trace, we randomly extract from
+  probability distributions the visibility of satellites. We also
+  randomize the time to fetch signals.
+\item Figure comparing clouds of points with only GPS and GPS+IMU in
+  the axis \emph{accuracy} (sum of distances from the ideal GPS trace)
+  and \emph{power consumption} (due to antenna).
+\end{itemize}
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