Lab 8: Culmination of Field Navigation Exercises

Introduction:

The past three entries in this blog have covered topics involving field navigation techniques. Using an aid to orient oneself with an area that is unfamiliar is a key component of being a geographer, and the principal application for a map. A good map leaves the viewer more spatially educated with the content being displayed. The importance of accurate navigation was applied more practically with these previous lab exercises, with a new skill being learned in each one. The first, the creation of a field navigation map, demonstrated the importance of accuracy in cartography skill, as the map, in combination with the compass, was the only aid in navigating the environment surround the Priory, a piece of real estate purchased by the University of Wisconsin Eau Claire. The second activity involved using the map and compass to effectively navigate around land surrounding the Priory, visiting certain navigation points along the way. The third activity transitioned to more technology-intensive field navigation techniques, and employed the use of a Garmin E-Trex GPS unit to navigate to certain coordinates where the navigation points were located. Each activity educated us in the various ways to accurately position oneself in their environment to get where they needed to go. The final activity served as a culmination of each of these sets of skills. For this week, we were to visit all of the navigation points, instead of only following a specified route like the previous activities. Eliminating the start points of each loop left each group to find 15 points, using a field map and E-Trex for assistance. To make the activity more interesting, we were equipped with Tippmann A-5 paintball markers, shown in Figure 1, and told to engage other groups if we encountered them. This added another variable to the activity, with what was previously a leisurely walk in the woods to a fast-paced, competitive scenario that required our navigation skills, as well as testing us physically.

Figure 1: A Tippmann A-5 paintball marker, used in this activity

Methodology:

The first process that needed to be done for this activity was to create another field navigation map, similar to the one that was created in the first activity. Once again, we were given a good deal of creative freedom with what to include in our maps. Similar to the first navigation exercise with the map and compass, a UTM grid was essential for navigation, as the coordinates could be used in conjunction with the navigation points that were provided in the previous lab activity to use the Garmin E-Trex to drop a way point at the desired navigation point, and then use the GPS to navigate there. A number of images of the City of Eau Claire could be selected as a base layer of the map, to get a reference point before starting to navigate the terrain. Like in the first exercise, an aerial image of Eau Claire West, the Southeast quadrant, served as the base layer, which was obtained through the WROC_Specs PDF file in a data folder that we were provided with prior to map design. One piece of data that was not included in the first field navigation map creation activity was a No Shoot Area, which we were required to put in the map. Due to the Priory's primary function as a daycare center for young children, we needed to have a wide buffer between where the kids could be, and where we, and our paintball markers, were. The resulting map that was used in the field activity, which clearly demonstrates the No Shoot Zones, can be seen in Figure 2 below.

Figure 2: Field Navigation map used in the paintball activity, with the No Shoot Zones and the navigation point boundary clearly marked for reference

Figure 3: Latitude, longitude, and UTM coordinates of navigation points for the lab activity

Once arriving at the Priory, each person was given an E-Trex, and a Tippmann A-5. The GPS unit was used primarily to provide a record of the tracklog, so that we could examine our routes after completing the activity. Another function that the GPS provided was the ability to drop way points on our current location, serving as proof of each group arriving at a particular navigation point. Figure 3 shows the UTM coordinates of the fifteen points that we had to navigate. Our group did not utilize these coordinates, however, choosing to rely on our paper map and experience in the wilderness for the two previous activity, to navigate the Priory. Like the previous navigation activity, after completing the navigation, we were required to take the GPS unit and download the tracklog and way point data. Again, we used DNRGPS, an open source piece of software that was built to transfer data between Garmin handheld GPS receivers and GIS software, like ESRI ArcMap, the software package that we used for this activity. After being downloaded, the tracklog and way points were imported into a geodatabase as point feature classes, and then brought into ArcMap to be manipulated further to create the maps found below.
Navigation was significantly more taxing this time due to the presence of the other groups that could open fire on us at potentially any time. The map of our tracklog, shown in Figure 4, demonstrates this perfectly. The route that we took was not organized well, with no real strategy employed from getting from point to point.  The video below the map, made by using the time field on the GPS tracklog data, is a time-based animation, showing the order of points collected.

Figure 4: Field map with imagery of the Priory, no-shoot zones, navigation points, and way points dropped on the routes to get to each navigation point.

Discussion:

Conducting this activity as the capstone of our navigation activities that have been occurring the past few weeks was a great idea. Adding that element of surprise provided by the use of paintball guns was a great challenge to keep us on our toes and change up the dynamic of the class. However, with all of the excitement and potential for engagement of other teams, collecting all of the navigation points proved difficult. Our group, Group 2, managed to collected the most points, but we were one short of getting all fifteen, and I believe that can be attributed to the excitement that led up to a massive firefight that we were involved in. Figures 5-9 below show maps of the other five groups' routes to get from navigation point to point. As we were looking for point 5A, our group saw two other groups that had joined forces and were coming right for us. After engaging them, we forgot to look for the point we were so close to. That is something that would not have happened while simply navigating on foot, without the potential of having to shoot at other teams. Additionally, in the excitement of a firefight, sometimes the GPS unit accidentally dropped a way point, which caused confusion when trying to gauge how many more navigation points our group needed to collect. This also was a contributing factor in failing to collect all of the points, as we believed that we had all of them for at least half of the duration of the activity.

Figure 5: Field map showing the movement of Group 1 in their route to visit all of the navigation points. They managed to arrive and drop way points 11 of the 15 possible navigation points.

Figure 6: Field map showing the movement of Group 3 in their route to visit all of the navigation points. They managed to arrive and drop way points 13 of the 15 possible navigation points.

Figure 7: Field map showing the movement of Group 4 in their route to visit all of the navigation points. They also managed to arrive and drop way points 13 of the 15 possible navigation points.

Figure 8: Field map showing the movement of Group 5 in their route to visit all of the navigation points. They appear to have only managed to arrive and drop way points 8 of the 15 possible navigation points, despite the tracklog record saying that they came close to two points, without dropping a waypoint

Figure 9: Field map showing the movement of Group 6 in their route to visit all of the navigation points. They managed to arrive and drop way points 10 of the 15 possible navigation points.

An issue that did manifest itself in the activity, and the resulting data manipulation was that of GPS accuracy, which was addressed in the previous post. As visible on the map in Figure 4, the way points that were recorded are off slightly from the coordinates of the navigation points, when they should, in theory, be right on top of one another. This is due to a phenomenon called Positional Dilution of Precision, or PDOP, and is an issue that plagues most GPS units, especially smaller ones like the Garmin E-Trex. If there are not enough satellites being able to be received by the GPS, the accuracy of the points can be incorrect. So even though all of the way points were taken right next to the navigation points markers, the heavy tree cover in the area disrupted the clear transmission of the signal to the GPS, resulting in a position disparity between the way points, and the coordinates of the navigation points.
The benefit to using both a GPS unit and a field navigation map in conjunction with one another was clear. Instead of relying on the field map and compass alone, like in the previous activity, and having to walk a straight line in even-paced steps to successfully find the navigation point, the map was used as a supplement to the GPS unit, which was the most effective way to navigate that we have utilized. In the previous blog post, I went into the positives and negatives to relying solely on one of the methods, and ultimately arrived at the conclusion that using both a GPS unit and an accurate field map would ultimately produce a navigation route that would present the least amount of obstacles to the navigator. The paper map would not run out of batteries, and would not have PDOP issues, while the GPS unit would not require the user to plot out bearing directions and walk in perfectly straight lines to reach the desired destination. The two, when used together, made this the most effective navigation exercise, despite the fact that there was the possibility of other groups engaging us with their paintball markers on the way to drop way points at the navigation points.

Conclusion:

The navigation activities at the Priory, and this exercise which required us to use all of our newly acquired knowledge were fantastic learning opportunities. Being able to apply what we have learned in an environment where it is required is one of the best ways to truly understand something, because your ultimate success or failure is based entirely on your mastery of the content. It is up to you if you get all the points, or if you get lost, confused, or do a poor job preparing for the outing. While a lot of individual work was required for this project, ultimately it was team exercise that demanded effective communication in order to be successful. Having each person keep a lookout for other teams and the navigation markers was absolutely essential to completing the activity in a timely fashion. Additionally, if a group member was able to traverse the snow faster than others, they could get the navigation point, while others who would be better reading the map could tell them where to go. Every group member's strengths could be highlighted during this activity, and effective utilization of these skills was a key factor, I believe, in our group's ability to get the most amount of navigation points collected.