Monthly Archives: June 2012

GPS Tracking Test, Take 2!

On Tuesday, while shopping for AK’s trip to excavate in Hungary, I came up with an idea for how to have participants in my research carry the GPS trackers. I found some colourful carabiners, binder rings, and name tag pouches and thought I could MacGyver something useful. My original plan was to punch a hole through the one front portion of the name tag holder so I could run a binder ring through it and one of the holes that are part of the name tag holders original ‘construction’– I hoped this would keep the pouch closed, I was then going to put the carabiner through the ring so it could be attached to something on the person. Unfortunately, the pouches were slightly too small for that.

The next flaw in my plan was actually being able to open the binder rings. It took a lot of time, pain, and persistence but I was eventually able to open them– one by painful one. Once the ring was opened once it became much easier to open it after that. There was still the slight issue of how to hook this onto the pouch and keep the pouch closed so the tracker wouldn’t fall out.

I noticed that there was ample room to punch a small hole in the pouch to the side of the GPS tracker so I decided this would be the next best course of action. Of course, I didn’t have an actual hole punch so I used a staple remover to cut a small hole through both sides of the pouch. The binder ring fit through the hole easily and I clipped the carabiner on. It was much more secure than I thought it would be, and the plastic didn’t tear at all. And finally, to close the pouch so the GPS tracker wouldn’t fall out, I taped down the top flap of the name tag holder where a lanyard or string would normally be attached– there was only some cheap scotch tape in the apartment so I used that but will need to get some better tape if this is the route I choose to go in the end.

This time I only took two of the trackers with me so I could save the other pouches for when I had an actual hole punch. The route turned out a bit better than last time, but one of the units did a few random off shoots. They didn’t last long at all so I’m not overly worried about it at this point but I’ll keep an eye on it as I do more tests at home and in the field.

This is what I MacGyvered to carry the GPS trackers by clipping it to something instead of having to hold it.
‘Look Ma, no hands!’

GPS Trial Run

Since I am currently at Banting House NHSC, between visitor groups, I thought I would take this opportunity to write a little about my (brief) experience testing the GPS Trackers for my MA project so far.

A couple of days ago I decided to test one of my GPS Trackers out when I went on my run, and I was surprised how well it worked. The route was a couple of meters off in places, and when I went through the forest path the signal must have bounced around a bit since my route was off more there, but in all it was fairly accurate. I suspected the trees would decrease the accuracy of the unit but I had hoped it wouldn’t be so bad. So, aside from the tracker suggesting I am Kitty from X-Men and can run through walls I was rather impressed. I used Google Earth to view the map the tracker produced and examined the stats I received about distance and speed from the program associated with the tracker– I was surprised to find I had gone 2.55 miles that morning.

The next day I went for a short walk carrying all four of the trackers, and took waypoints along the way, to test how consistent the set of them are. I went through the forest again and was pleased to discover that the set produced relatively the same route as one another so I am going to need to do more experimenting in there to see what is going on. The rest of the route and the waypoints were generally within a few feet of each other. When I backtracked along the route there were minor differences between the initial and return route but that could also be me misremembering where exactly I had walked.

At the moment I suspect that some of the inaccuracies and inconsistencies are due to the small felt pouches the manufacturer provide to protect the units. I carried the trackers in these in case, by some small chance, I happened to drop one– I didn’t want to scratch the units unnecessarily. Over the next few days I plan to test them again without the felt pouches to see if these had an impact on the results. I am hoping that the accuracy and consistency will be higher during these tests so I will know if it is best to leave the units uncovered. It is also my intention to try different techniques of carrying the units, including having them clipped to a bag or belt loop, if I can find the appropriate item for this task. Hopefully a carabiner and a thin plastic cover will work for this and not impact the results.

I am hoping that the statistics provided by the program associated with the trackers will be able to provide interesting information about how long people spend at the archaeological site museum and how quickly they move throughout the site and on their tour. And, of course, I will be sure to test the accuracy and consistency of the units at the site when I get there so I will have an idea about the reliability of the data logged by the trackers; I will also be marking the units and the memory cards so I can be sure to keep the pairings of these the same during my tests and research.