Thursday, May 15, 2014

Field Activty #12: GPS Navigation


In a previous exercise each student was asked to develop a map of The Priory for the purpose of navigation. In exercise 11, groups experimented with using a physical copy of the map to navigate to several points throughout a course at the Priory set up by Professor Joe Hupy and others. This time the goal for each group was to navigate to all 15 points set up on the course using our map loaded onto a Juno GPS unit.

Adding a little spice to this operation, each team member, other than the navigator, was equipped with a paintball gun. If any of the members of your group were hit by a paintball, the entire group had to wait 30 seconds before continuing to navigate the course. Each group was given a designated start point. Other than that, it was up to each group to decide how they would like to complete the course. However, there were several areas including "no shooting zones" that we had to avoid crossing through.


Database Creation and Deployment

First, we had to determine which of the maps previously created by the members of our we would use as a basemap. The initial features included a background raster, the no shooting zones, course points, and contour lines.

We decided it would be best to predetermine our route based on our starting location, the topography, and the most direct path to complete the course. Distances between points were calculated and compared. Also, we walked through our proposed route and compared slope and terrain to make sure the route was still ideal with that consideration in mind. After Brendan Miracle and I formulated this route, we added a new field for our point labels based on the order we wanted to complete the points and also digitized route lines in-between the points. There was some complication in keeping the numbers straight because each point had already been assigned a number. After double-checking our work, we were confident our route was labeled in the right order.

Then we were ready to deploy our map (as seen in Figure 1) to our Juno GPS Unit.

Figure 1: This is the course navigation map that was uploaded to the Juno GPS unit for our Priory navigation exercise. Points are labeled in the order we would navigate to them. While the route lines show us going through a no-shooting zone, it was understood that we would navigate around it.
In addition to the map deployed on the Juno GPS, we decided to bring along a paper copy of our map as well. This turned out to be a very key choice for us later in the exercise.
Course Navigation
As previously mentioned, three members of our group were armed with paintball guns while a fourth member was charged with navigation. As we began to walk to our initial starting point, we booted up the GPS. It took quite some time to actually locate a signal, so we waited while another group passed us that would be starting at the same point. Once we acquired a signal, we began course navigation.
The first three points were easily located, but by the third point we had encountered another group. When the paintballs started flying things began to get a little hectic. First, our navigator encountered some difficulty assessing the situation with all that was going on. Second, the Juno GPS unit was completely bogged down and would take a very long time to load as we tried to zoom in and load the location of points we had reached.
We were very quickly off-course as a result and the fourth point we located was actually down in a deep ravine. Here, the GPS unit completely froze on us and turned off. We wasted a significant amount of time trying to get it back on and loaded up so that we could load the fourth point and could not do this successfully - even to the point where the map would not load again.
With time wasting, we decided to navigate using the paper map we had brought along, and told the navigator to monitor the GPS to see if we could get it working as we went along. Things began to move much more smoothly once we ditched technology. We got back on track and started to move rather well through a significant number of the points.


We made one very crucial mistake in preparation for this exercise. By choosing to include so many features in our map, the Juno GPS just had too big of a job moving in and out and acquiring locations as we tried to move quickly through the course. That is why it got bogged down to the point where we had to make the choice to ditch the technology.
Also, the added element of paintballs provided just enough distraction for our navigator where it was difficult to employ their knowledge of navigation. With more familiarity in navigation, this would probably not be as much of a problem.
Once we moved on to the paper map, we still encountered some difficulties. It was hard to gauge the distance traveled by foot with area covered on the map. In our haste, we failed to even try to keep track of some general measurements that would have helped us. As a result, there were still many moments where we had to stop for a couple minutes and reason out our current location relative to where we were trying to go. It many have been wise to bring some other form of measurement to help us compare to the scale of the map as we traveled.


Navigation is not something to enter into haphazardly. We were only able to reach 12 of the 15 points before time expired. And, the last five of these were reached in misery and frustration on the part of most of the group.
As a result, I learned the following:
  • Map data deployed to Juno GPS should be minimal but effective; throw aesthetics out the window
  • Always bring another form of navigation other than a technological instrument
  • Carrying a tool to measure distance as you travel could be extremely helpful
  • Be very deliberate as you navigate; it does not take much to send things spinning out of control especially if you are not a seasoned navigator
  • Become familiar with the feeling of distance traveled over terrain with elevation; it is not at all similar to gauging distance walked over flat ground

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