Lab 8: GPS Navigation With a Map

Introduction

            For our third and final trip to the Priory, our task was to utilize all of the methods previously explained in the posts below describing the different technology used for navigation. The objective was to find as many points as possible within our three hour lab time using whatever technique we thought was most efficient. The class was broken into six groups and the group who navigated and found the most way points was the winner. To add another variable to the competition, each team member was outfitted with a Tippmann A5 paintball marker that would be used to engage opposing groups when navigating. Due to the stigma that surrounds any aggressive looking black piece of plastic and metal that has a barrel and shoots any sort of projectile, we had to be very careful when navigating from point to point. Although Dr. Hupy cleared the activity with the appropriate University Administrators, we still had to be careful due to the fact that the Priory doubles as the University’s daycare center. We added a clearly defined “No Shoot” area to our navigation maps that specifically outlined the areas we were not allowed to be in. Since this was our third trip to the Priory and we were getting familiar to the area, staying within the new navigation boundary was not an issue.

Figure 1: Shown above is the navigation map used. It clearly depicts the "No Shooting Zone" at the Priory.

Methods

            Like last week, each team was given a Garmin E-trex GPS unit to aid in navigation. Again, the only function allowed to be used on the GPS was the real time display of the GPS unit’s current position shown in UTM NAD 83 Zone 15 N coordinates. In addition to the GPS unit, teams were also allowed to possess a reference navigation map much like the one used in lab six. By combining the two resources and using them in unison, navigation was done with relative ease.

            To again show the efficiency of each team as they moved from way point to way point, the track log function was turned on within the GPS. In addition to the track log automatically plotting a point every 30 seconds to for a digital trail of breadcrumbs, each team member was also required to manually plot a way point on the GPS once a navigation marker was found in the field.

            The score cards used to validate that a team found a way point were to be punched by a hole punch connected by a string to that navigation marker that was unique to each respective navigation marker.

Figure 2: Shown above is the score cards used to validate and record the successful location of a way point.

 

            In addition to just arbitrarily wandering from way point to way point like the previous past trips to the Priory, the addition of paintball markers aimed to up the level of completion. Teams were allowed to engage opposing teams at will but if any member of your team got hit, it was required that you cease all movement and fire for five minutes.

Figure 3: The image above shoes the paintball equipment used for this navigation exercise at the Priory.

 

Discussion

            Unlike last week, where it took our team a considerable amount of time to orient ourselves using nothing but the GPS for navigation, we were able to begin traveling to the first way point immediately. We were able to do this because of the navigation map we possessed that pinpointed our location as soon as our GPS units got a satellite fix. Once we oriented ourselves we then created a route that would most efficiently direct us to the most amount of points in the least amount of time.

Figure 4: Shown above is the track log feature class from our team that was automatically recorded by the Garmin GPS unit.

Figure 5: Displayed on this map is my track log feature class as it was recorded by the Garmin GPS unit.

Figure 6: Shown above is the way point feature class I recorded at each navigation way point located in the field. Notice the deviation due to canopy cover from the GPS point I recorded and the actual location of the navigation way points.

 

Clearly shown by the track log data for our group, a minimal amount of “zig-zagging” was done from point to point. Once a direct route was established on the map we stayed on that bearing using the compass function within the GPS. Since we didn’t have to follow the specific bearing like we did when navigating with only a compass and pace count regardless of the areas topography, we also were able to navigate around much of the nasty terrain to avoid steep hills and deep valleys. We were able to do this because we always knew our exact location within the Priory by utilizing both the map and GPS unit simultaneously.

Conclusion

            Aside with my obsession with paintball guns, I found this lab both extremely enjoyable and educational at the same time. It again provided a perfect example of how useful GPS technology and the UTM coordinate system are. It also reinforced my understanding of the UTM coordinate system by having us walk around following the UTM coordinates displayed on the GPS. By doing this, it showed again how they are simply broken down into meter increments that are northing and easting from the origin of Zone 15 N. I also like how it called upon the skills we learned in lab six on how to navigate with a compass bearing because that knowledge greatly increased our team’s efficiency in finding the predefined way points. The progression from low tech land navigation to the higher tech methods like GPS was perfect because it showed how the same result can be obtained with different methods. This wide array of skills allowed for us to not only find the way points with the least amount of energy, but also showed how important it is to have back up methods so completion of a task can be done regardless of equipment failure or malfunction.