Added second rssi plot, LOS test setup

tex/chapters/8_experiments.tex

@@ -79,10 +79,17 @@ In contrast to \etal{Ibrahim} we use smartphones as receivers and two different
 Additionally, it is unclear how the external antennas affect the measurements.
 For these reasons we did a static distance measurement experimental setup to confirm that the combination of Pixel devices and Intel cards provide reliable values. 
 
-% TODO fig mit shematischen aufbau
+\begin{figure}[ht]
+\centering
+\newcolumntype{c}{>{\footnotesize}l} % HACK: Inkscape erzeugt ein tablular und ignoriert die font size
+\input{gfx/DistMeasExpLOS.pdf_tex}
+\caption{Experimental setup in the main hallway of our university building. Every \SI{2}{m} 140 FTM measurements were recorded from the smartphone (Green) to the responder (Blue). The AP is close to a stair } % TODO Das mit der Treppe besser erklären
+\label{fig:LosDistExp}
+\end{figure}
 
 Our test setup consist of $10$ measurement points evenly spaced at a distance of \SI{2}{m} on a straight line.
 The closest point to the AP is \SI{2}{m} away and the furthest \SI{20}{m}.
+The setup is shown in \autoref{fig:LosDistExp}.
 At every point each phone is placed on a stand.
 Around 140 FTM measurements are recorded, which corresponds to a measure period of \SI{30}{s} per point.
 The APs and the phones are placed on an empty cardboard box on a metal stand to allow some distance between the metal and the phone.
@@ -179,7 +186,7 @@ However, the overall error of the device combinations is reasonable small and it
     \subfloat[]{\label{fig:DistMeasMeanNucPixel:b}\includegraphics[]{MeanDistIntel.pdf}}
 \par\medskip
     \subfloat[]{\label{fig:DistMeasMeanNucPixel:c}\includegraphics[]{DistErrorCdf.pdf}}
-    \caption{\ref{fig:DistMeasMeanNucPixel:a}, \ref{fig:DistMeasMeanNucPixel:b} show the mean distance per smartphone and per access point, respectively. \ref{fig:DistMeasMeanNucPixel:c} is the CDF of the measurement error for each device combination.}
+    \caption{\textbf{(a)} \textbf{(b)} the mean distance per smartphone and per access point, respectively. \textbf{(c)} the CDF of the measurement error for each device combination.}
     \label{fig:DistMeasMeanNucPixel}
 \end{figure}
 
@@ -217,31 +224,14 @@ However, the overall error of the device combinations is reasonable small and it
 
 During the analysis of the recorded data of the test walks presented below systematic and reproducible deviations of the estimated position to the groundtruth were found.
 These effects increased the error significantly and are bound to specific locations in the building.
-It is likely that environmental factors of the building at these locations affect the FTM distance measurements process.
+It is likely that environmental factors of the building at these locations affect the FTM distance measurement process.
 %Therefore, environmental factors of the building structure at these locations are likely to affect the FTM distance measurements.
 While it is well known that the environment will affect measurements, especially indoors, it is nevertheless interesting to analyses the underlying cause.
 It was noticed that the ranging measurements to one access point suddenly started to heavily overestimate the true distance.
 This effect occurs as soon as the pedestrians walks by a fire door.
 These heavy doors are about \SI{12}{cm} thick and made of metal.
 In the case of a fire outbreak these doors are automatically closed, but normally they are not closed and tucked away between walls.
-Whenever such fire door is in the line of sight between the access point and smartphone the ranging error increases significantly.
+Whenever such fire door is in the line of sight between the access point and the smartphone the ranging error increases significantly.
-
-To quantify the impact of these fire doors on the FTM measurement we created two test setups as seen in \autoref{fig:BSTExp}.
-In the first experiment, as shown in \autoref{fig:BSTExp:a}, we used the same access point position as in the test walks of the next section.
-We placed seven measurement points on a circle so that most of these points are located in the main hallway.
-The radius of the circle is \SI{10}{m} and measure point 1 to 3 are located in the shadow of the fire door while points 4 to 7 are not.
-At every point we placed the \pixelOld on a metal stand \SI{1.05}{m} above the floor and recored FTM distance measurements for \SI{60}{s} with one measurement every \SI{200}{ms}, which results in around 255 successful distance measurements per point.
-%Note that this number is the mean of all successful measurements and the theoretical number of total measurements should be 300.
-Note that this number differs from the theoretical possible 300 measurements because some measurements fail due to NLOS.
-
-The results are depicted in \autoref{fig:Bst1Results}.
-The error in the shadow area is larger compared to the points not shadowed by the fire door.
-While the mean distances at point 1 and 2 are off by around \SI{10}{m} the error decreases monotonously for the following points.
-Point 5 to 7 are not affected by the fire wall with a mean error of \SI{0.8}{m}.
-But the deviation at point 4, which signal path is quite close to the door, is somewhat larger.
-The distribution of the distances recorded at point 2 has two modes at \SI{16.55}{m} and \SI{34.12}{m}.
-
-
 
 \begin{figure}[ht]
 \centering
@@ -253,32 +243,59 @@ The distribution of the distances recorded at point 2 has two modes at \SI{16.55
     \centering
     \subfloat[]{\label{fig:BSTExp:b}\includegraphics[width=0.8\textwidth]{VersuchsaufbauBST2.png}}
 \end{minipage}\par\medskip
-\caption{Test setups to evaluate the impact of fire doors (red lines) compared to regular walls (black lines). In \ref{fig:BSTExp:a} the measurement points are placed on a circle to keep the distance constant. The setup of \ref{fig:BSTExp:b} allows more measurement points. }
+\caption{Test setups to evaluate the impact of fire doors (red lines) compared to regular walls (black lines). In \textbf{(a)} the measurement points are placed on a circle to keep the distance constant. The setup of \textbf{(b)} allows more measurement points. }
 \label{fig:BSTExp}
 \end{figure}
 
-Notice that point 2, 3, 5 and 6 are located near stairways with massive metal railings.
+To quantify the impact of these fire doors on the FTM measurement we created two test setups as seen schematically in \autoref{fig:BSTExp}.
-It is expected that the stairways also disturb the measurement additionally, but they are still of real interest because they are included in the test walks.
+In the first experiment, as shown in \autoref{fig:BSTExp:a}, we used the same access point position as in the test walks of the next section.
-
+We placed seven measurement points onto a circle so that most of these points are located in the main hallway.
-
+The radius of the circle is \SI{10}{m} and measure point 1 to 3 are located in the shadow of the fire door while points 4 to 7 are not.
-In order to evaluate the effect of the fire door exclusively, we build a second test setup at a corner office located next to a fire door.
+At every point we placed the \pixelOld on a metal stand \SI{1.05}{m} above the floor and recored FTM distance measurements for \SI{60}{s} with one measurement every \SI{200}{ms}, which results in around 255 successful distance measurements per point.
-As seen in \autoref{fig:BSTExp:b} it was not possible to keep the distance to the AP constant, due to structural limitations. 
+%Note that this number is the mean of all successful measurements and the theoretical number of total measurements should be 300.
-The groundtruth was obtained by carefully measuring the distances to walls and taking the line of sight distance from a true to scale map.
+Note that this number differs from the theoretical possible 300 measurements because some measurements fail due to NLOS.
 
 \begin{figure}[ht]
 \centering
 \subfloat[]{\label{fig:Bst1Results:a}\includegraphics[]{BSTPlot1.pdf}}\hspace{0.25cm}
 \subfloat[]{\label{fig:Bst1Results:b}\includegraphics[]{BSTPlot1Rssi.pdf}}
-\caption{}
+\caption{Results for test setup as seen in \figref{fig:BSTExp:a}. \textbf{(a)} While the true distance (black line) is constant the mean measured distance (blue line) is not. At point 2 a bimodal distribution of measurements is apparent. If only the larger mode is used the error decreases monotonously (dashed cyan line). \textbf{(b)}  Corresponding RSSI values at each measurement point.}
 \label{fig:Bst1Results}
 \end{figure}
 
+The distance measurement results are depicted in \autoref{fig:Bst1Results:a}.
+The error in the shadow area is larger compared to the points not shadowed by the fire door.
+While the mean distances at point 1 and 2 are off by around \SI{10}{m} the error decreases monotonously for the following points.
+Point 5 to 7 are not affected by the fire wall with a mean error of \SI{0.8}{m}.
+But the deviation at point 4, which signal path is quite close to the door, is somewhat larger.
+The distribution of the distances recorded at point 2 has two modes at \SI{16.55}{m} and \SI{34.12}{m}, which are clearly visible in the plot.
+This bimodal distribution increases the mean distance significantly, if, instead of the mean, the distance at the larger mode (\SI{16.55}{m}) is used, then the overall curve is monotonously decreasing (cyan dashed line).
+
+
+The mean RSSI, as shown in \autoref{fig:Bst1Results:b}, exhibits the same tendency as the mean distance.
+At points 1, 2 and 3 the RSSI is decreasing with a minimum at point 4 and stable for the remaining points.
+This suggest that the RSSI correlates somewhat with the measured distances in this scenario, except at point 4 where the RSSI is stronger than every other point.
+However, this could be caused by measurement inaccuracy of the smartphone chip and might be a nonrecurring outlier.
+The RSSI compared to FTM measurements have insignificant small variance in this test and very stable.
+
+
+Notice that point 2, 3, 5 and 6 are located near stairways with massive metal railings.
+It is expected that the stairways also add measurement noise, however, we still included them deliberately in this test setup as they are nonetheless of real interest because they also appear in the test walks.
+
+
+In order to evaluate the effect of the fire door exclusively, we build a second test setup at a corner office located next to a fire door on the same floor.
+As seen in \autoref{fig:BSTExp:b} the measurement points are placed parallel to the wall, due to structural limitations it was not possible to keep the distance to the AP constant.
+The groundtruth was obtained by carefully measuring the distances to walls and taking the line of sight distance from a true to scale map.
+
+
+
 
 \begin{figure}[ht]
 \centering
-\includegraphics[]{BSTPlot2.pdf}
+\subfloat[]{\label{fig:Bst2Results:a}\includegraphics[]{BSTPlot2.pdf}}\hspace{0.25cm}
+\subfloat[]{\label{fig:Bst2Results:b}\includegraphics[]{BSTPlot2Rssi.pdf}}
 \label{fig:Bst2Results}
-\caption{Results for setup as seen in \figref{fig:BSTExp}. While the groundtruth distance only slightly varies (black line) the mean measured distance (blue line) varies greatly depending on the relative position to the fire door.}
+\caption{Results for setup as seen in \figref{fig:BSTExp:b}. While the groundtruth distance only varies slightly (black line) the mean measured distance (blue line) varies greatly depending on the relative position to the fire door.}
 \end{figure}
 
 

tex/gfx/DistMeasExpLOS.pdf_tex

@@ -0,0 +1,62 @@
+%% Creator: Inkscape inkscape 0.92.4, www.inkscape.org
+%% PDF/EPS/PS + LaTeX output extension by Johan Engelen, 2010
+%% Accompanies image file 'DistMeasExpLOS.pdf' (pdf, eps, ps)
+%%
+%% To include the image in your LaTeX document, write
+%%   \input{<filename>.pdf_tex}
+%%  instead of
+%%   \includegraphics{<filename>.pdf}
+%% To scale the image, write
+%%   \def\svgwidth{<desired width>}
+%%   \input{<filename>.pdf_tex}
+%%  instead of
+%%   \includegraphics[width=<desired width>]{<filename>.pdf}
+%%
+%% Images with a different path to the parent latex file can
+%% be accessed with the `import' package (which may need to be
+%% installed) using
+%%   \usepackage{import}
+%% in the preamble, and then including the image with
+%%   \import{<path to file>}{<filename>.pdf_tex}
+%% Alternatively, one can specify
+%%   \graphicspath{{<path to file>/}}
+%% 
+%% For more information, please see info/svg-inkscape on CTAN:
+%%   http://tug.ctan.org/tex-archive/info/svg-inkscape
+%%
+\begingroup%
+  \makeatletter%
+  \providecommand\color[2][]{%
+    \errmessage{(Inkscape) Color is used for the text in Inkscape, but the package 'color.sty' is not loaded}%
+    \renewcommand\color[2][]{}%
+  }%
+  \providecommand\transparent[1]{%
+    \errmessage{(Inkscape) Transparency is used (non-zero) for the text in Inkscape, but the package 'transparent.sty' is not loaded}%
+    \renewcommand\transparent[1]{}%
+  }%
+  \providecommand\rotatebox[2]{#2}%
+  \newcommand*\fsize{\dimexpr\f@size pt\relax}%
+  \newcommand*\lineheight[1]{\fontsize{\fsize}{#1\fsize}\selectfont}%
+  \ifx\svgwidth\undefined%
+    \setlength{\unitlength}{425.19685039bp}%
+    \ifx\svgscale\undefined%
+      \relax%
+    \else%
+      \setlength{\unitlength}{\unitlength * \real{\svgscale}}%
+    \fi%
+  \else%
+    \setlength{\unitlength}{\svgwidth}%
+  \fi%
+  \global\let\svgwidth\undefined%
+  \global\let\svgscale\undefined%
+  \makeatother%
+  \begin{picture}(1,0.41333333)%
+    \lineheight{1}%
+    \setlength\tabcolsep{0pt}%
+    \put(0.18441068,0.15139591){\color[rgb]{0,0,0}\makebox(0,0)[t]{\lineheight{1.25}\smash{\begin{tabular}[t]{c}\SI{2}{\meter}\end{tabular}}}}%
+    \put(0.41478691,0.17971616){\color[rgb]{0,0,0}\makebox(0,0)[t]{\lineheight{1.25}\smash{\begin{tabular}[t]{c}\SI{20}{\meter}\end{tabular}}}}%
+    \put(0,0){\includegraphics[width=\unitlength,page=1]{DistMeasExpLOS.pdf}}%
+    \put(0.98439368,0.12440651){\color[rgb]{0,0,0}\rotatebox{-90}{\makebox(0,0)[t]{\lineheight{1.25}\smash{\begin{tabular}[t]{c}\SI{5}{m}\end{tabular}}}}}%
+    \put(0,0){\includegraphics[width=\unitlength,page=2]{DistMeasExpLOS.pdf}}%
+  \end{picture}%
+\endgroup%

tex/plots/BSTPlot1.pgf

@@ -17,8 +17,10 @@
 	%enlarge y limits=false,
 	ymin=0,
 	xtick={1,2,3,4,5,6,7},
+	ytick distance=5
 ]
 \addplot [color=black] table[x=X,y=GT,col sep=comma]{../data/BSTMean1.csv};  \addlegendentry{Groundtruth}
+\addplot [color=cyan, dashed] table[x=X,y=MeanDistOnMode,col sep=comma, forget plot]{../data/BSTMean1.csv};   
 \addplot [color=blue] table[x=X,y=MeanDist,col sep=comma]{../data/BSTMean1.csv};  \addlegendentry{Mean distance}
 \addplot [color=orange, mark=x, only marks, mark size=1.5pt, line width=0.5pt] table[x=X,y=Y,col sep=comma]{../data/BSTData1.csv};  \addlegendentry{Measured distance}
 \end{axis}

tex/plots/BSTPlot1Rssi.pgf

@@ -7,6 +7,7 @@
 	width=6.5cm,
 	height=6.5cm,
 	ybar,
+	bar width=0.75,
 	xtick align=inside,
 	xlabel ={Measurement point},
 	ylabel ={RSSI in \si{\dBm}},

tex/plots/BSTPlot2.pgf

@@ -4,7 +4,8 @@
 \small
 \begin{tikzpicture}
 \begin{axis}[
-	width=15.7cm,
+	%width=15.7cm,
+	width=8.2cm,
 	height=6.5cm,
 	xlabel ={Measurement point},
 	ylabel ={Distance in \si{\meter}},
@@ -15,6 +16,8 @@
 	%yminorgrids=true,
 	enlarge x limits=false,
 	%enlarge y limits=false,	
+	xtick={1,2,3,4,5,6,7,8,9,10,11,12,13},
+	ytick distance=5
 ]
 %\draw ({axis cs:7,0}|-{rel axis cs:0,1}) -- ({axis cs:7,0}|-{rel axis cs:0,0});
 \addplot [color=black] table[x=X,y=GT,col sep=comma]{../data/BSTMean2.csv};  \addlegendentry{Groundtruth}

tex/plots/BSTPlot2Rssi.pgf

@@ -0,0 +1,29 @@
+\documentclass[tikz]{standalone}
+\input{../PlotPreamble.tex}
+\begin{document}
+\small
+\begin{tikzpicture}
+\begin{axis}[
+	width=7.5cm,
+	height=6.5cm,
+	ybar,
+	bar width=0.75,
+	xtick align=inside,
+	xlabel ={Measurement point},
+	ylabel ={RSSI in \si{\dBm}},
+	legend pos=north east,	
+	xmajorgrids=true,
+	%xminorgrids=true,
+	ymajorgrids=true,
+	%yminorgrids=true,
+	%enlarge x limits=false,
+	%enlarge y limits=false,
+	ymax=-55,
+	ymin=-75,
+	xtick={1,2,3,4,5,6,7,8,9,10,11,12,13},
+]
+\addplot [ta2skyblue, fill=ta2skyblue] table[x=X,y=RSSI,col sep=comma]{../data/BSTMean2.csv}; 
+%\addplot [blue, mark=x] table[x=X,y=RSSI,col sep=comma]{../data/BSTMean2.csv}; 
+\end{axis}
+\end{tikzpicture}
+\end{document}

tex/plots/_build.bat

@@ -7,6 +7,7 @@ cd out
 start %TEX% ../BSTPlot1.pgf
 start %TEX% ../BSTPlot1Rssi.pgf
 start %TEX% ../BSTPlot2.pgf
+start %TEX% ../BSTPlot2Rssi.pgf
 start %TEX% ../DistErrorCdf.pgf
 start %TEX% ../MeanDistIntel.pgf
 start %TEX% ../MeanDistPixel.pgf