Field Exercise 11 - GPS Navigation

INTRODUCTION

          In the previous field exercise our geospatial field methods class was tasked with navigating the rugged and wooded terrain of the UW-Eau Claire Priory using only a map and compass. The experience was a real crash course in field navigation. For this field exercise the class was tasked with navigating the same rugged and wooded terrain of the Priory but with a handheld GPS unit. The class was broken down into five different groups of three so that each group could navigate one specific area of the priory. To complete the navigation exercise each group had to mark off five different points of interest (POIs) on the maps we created for the previous field exercise (field exercise ten - orienteering with a map and compass) and navigate to them using a handheld GPS device. The five POIs each group marked on their maps of course corresponded to the area their navigation exercise was supposed to focus on. Once a POI was navigated to the group had to first, record the point on their GPS unit, second, mark a large tree on the point, and third, take a picture of its location. This process was repeated for all five points.

Study Area

          My group decided that we would take on the responsibility of navigating the far Northwestern corner of the Priory property. This corner of the property contained the most densely wooded and steepest terrain of any other area on the property. I was personally on board for choosing this area of the property because I thought it would be the most fun to navigate. After all what's a navigation exercise without some sweat and dirt mixed in? Figure one below shows a map of the UW-Eau Claire Priory and my groups area of interest (AOI).

Figure 1: shows a map of the UW-Eau Claire Priory and my groups corresponding AOI. The property line of the Priory is delineated by the black box, the five meter contour lines are marked with red lines, and my groups AOI is marked with a green box. 

METHODS

          As stated above my group and I navigated to five predetermined points located in the far Northwest corner of the UW-Eau Claire Priory property. My group and I tried to space out the points so that they were all equally far apart from each other. We also tried to locate the points on prominent land marks such as ridge tops and ravine forks. The five POIs that we marked prior to the navigation exercise can be viewed in figure two below.

Figure 2: shows the priory map and the five predetermined points which are marked with green dots. The five POIs are also labeled in the order which we navigated to them in.

In order to navigate to these five POIs my group and I decided to use a Trimble Juno 3 handheld GPS device. We chose to navigate with this unit because we were all very comfortable using this piece of equipment and It can obviously get the job done. My group and I were also carrying around print outs of the Priory map for easy reference. In order to navigate to the five POIs one member of our group was in charge of the GPS unit. This persons job was to make sure that we were always on course. Another member of our group was responsible for referencing the Priory map. This persons job was to make sure that the GPS was taking us in a sensible direction and that the GPS and Map were congruent with one another. The final group member was responsible for finding the quickest and most sensible path through the terrain. There job required them to constantly reference the map and their immediate surroundings. For our purposes it was this final job that proved to be the most important because of how rough the terrain was in the Northwest quadrant of the Priory property.

DISCUSSION

          After navigating to each of the five predetermined POIs, my group and I flagged a nearby tree and took a picture of it. Below in figures three-seven are pictures of the five POIs my group and I navigated to.

Figure 3: shows POI one. POI one was located just on the other side of the first big gulch that navigators have to traverse. 

Figure 4: shows POI two. POI two was located at the bottom of four converging ravines.  

Figure 5: shows POI three. POI three was located on the farthest point of the most Northern knob on the Priory property.



Figure 6: shows POI four. POI four was located at the top of another ravine and was quite close to someone's backyard shed.

Figure 7: shows POI five. POI five was located at the fork of two converging ravines and stands out in the open.

          Even though we were all comfortable with GPS unit my group had problems with it because we did not make any of the features editable. We could still take points of our locations, but using it for navigating to the five predetermined POIs was impossible. My group and I troubleshot this problem by utilizing the orienteering skills we garnered in the previous field exercise. We had a map and compass so we just followed our compass bearing until we reached where we had marked on the Priory map.

CONCLUSION  

          The exercise for this week was very similar to the prior weeks exercise albeit not as intense because we chose the points we were navigating to. My group's GPS unit failed to help us in our navigating efforts so it was a good thing that the previous weeks orienteering exercise prepared us to navigate with a map and compass. Overall I'm glad we did another navigation exercise because I think it's a fun way to learn and be active at the same time.