Fix more \approx

Author: Chris Lane

docs/report/tex/design.tex

@@ -283,6 +283,6 @@ \subsection{Proximity Warnings}
 \subsection{Freefall and Canopy Deploy Detection}
 After contacting several skydiving altimeter manufacturers and receiving either no response or being declined any information, we had to design our freefall detection parameters from scratch.
 
-The app should only log data from the point that a skydiver jumps from the plane to when they land on the ground. To detect freefall, we set a couple of prerequisites that must be met. Firstly, the altitude should be over a safe skydiving altitude of \SI{1500}{\metre} and secondly, the fall rate calculated for the user must pass \SI{20}{\metre\per\second}. The fall rate is reached \SI{\approx2}{\second} after jumping from the plane.
+The app should only log data from the point that a skydiver jumps from the plane to when they land on the ground. To detect freefall, we set a couple of prerequisites that must be met. Firstly, the altitude should be over a safe skydiving altitude of \SI{1500}{\metre} and secondly, the fall rate calculated for the user must pass \SI{20}{\metre\per\second}. The fall rate is reached \SI{\sim2}{\second} after jumping from the plane.
 
 Canopy flight will only ever happen after some freefall, and so for canopy flight detection, the first prerequisite is that freefall must have already been detected. The next prerequisite is that the fall rate must have dropped below \SI{15}{\metre\per\second}.

docs/report/tex/results-evaluation.tex

@@ -49,9 +49,9 @@ \subsection{Skydive Logging}\label{subsec:skydive-logging}
 \subsection{Proximity Warnings}
 The requirement that the user should be given warnings of obstacles while under canopy was implemented for the avoidance of other skydivers since skydiver collisions are very dangerous.
 
-The feature was tested by first attempting to connect two devices at the furthest range possible, achieved by having two people walk towards each other until a connection could be made, this was accomplished at a range of \SI{\approx50}{\metre} with a direct line of sight. A warning distance was set for anyone being within a range of \SI{15}{\metre}. The two devices were moved closer to each other until a warning was produced on one phone at a distance of \SI{\approx20}{\metre}, roughly two seconds later, a warning was produced on the second phone.
+The feature was tested by first attempting to connect two devices at the furthest range possible, achieved by having two people walk towards each other until a connection could be made, this was accomplished at a range of \SI{\sim50}{\metre} with a direct line of sight. A warning distance was set for anyone being within a range of \SI{15}{\metre}. The two devices were moved closer to each other until a warning was produced on one phone at a distance of \SI{\sim20}{\metre}, roughly two seconds later, a warning was produced on the second phone.
 
-The proximity warnings are not accurate. However, this would be expected with standard GNSS having an accuracy of \SI{\approx4}{\metre} as mentioned in Section~\ref{subsec:related-work}. It should be noted that the warning in this instance was produced at a longer distance which does raise any safety concerns. The feature should never be relied on entirely over existing safety measures, and so the feature can only increase the safety of a skydiver.
+The proximity warnings are not accurate. However, this would be expected with standard GNSS having an accuracy of \SI{\sim4}{\metre} as mentioned in Section~\ref{subsec:related-work}. It should be noted that the warning in this instance was produced at a longer distance which does raise any safety concerns. The feature should never be relied on entirely over existing safety measures, and so the feature can only increase the safety of a skydiver.
 
 Unfortunately, the feature is limited by the features of Android that require that connections be manually accepted by a user, meaning that if a connection is lost during a skydive then it cannot be made again without user input. This limitation could be overridden by ``rooting'' the phone to allow modifications to the system.