The latest project for field methods is a continuation of the previous lab titled Navigation Maps. Navigation Maps was a lab where two maps of the Priory were created that would be used to navigate through the Priory to find certain location marks. This lab used the navigation maps of the Priory to locate 5 markers that were scattered throughout the Priory. Along with the maps a combination of pace counts and compasses were used to help with the navigation process. The Priory contains 5 different sets of marks, also known as a course, for groups to find, however do to the overly large class size this semester there was a 6th group. Group 6 was assigned markers from multiple courses.
Methods
The method used to navigate threw the priory was rather simple. First the coordinates for the five markers were given to each group. The groups then marked the location of the markers on their maps to use be used to locate the course markers. Next, a pace count was needed to be created for every group member. A pace count is the amount of paces it takes for a person to walk a given distance, for this exercise meters were the units used for distance. To find the pace count a 50 meter tape measure was laid on the ground and a student would walk next to it while counting their steps. Once the student walked the entirety of the tape they could double their amount of steps or turn around and walk back. The pace counts that were used in group 4 were 110 paces per 100 meters for Payden and 135 paces per 100 meters for Sarah. The third group member had recently broken his leg and was unable to put to much stress on it. So he ended up being the note taker during the exercise. The next tool used to help navigate the Priory was a compass. Each compass was able to locate north and find the direction in degrees from north that the next marker is suppose to be located. The compass also had a 5 cm ruler on the side of it. The ruler was used to measure the distance on the map from one marker to the next. The centimeters would then be converted from map distance to actual distance using the map scale. The last piece of equipment used was a GPS unit. The GPS unit recorded the path of each group through the woods and showed how close to the markers each group got.
To give an example of how all of this worked lets say that the starting point was in the parking lot and the first point was 11 degrees west of north. The distance from the starting point to the first marker is 7 cm. The scale on the map says that 1 cm = 31.34 meters, so 7 * 31.34 = 219.38 m. If Payden, who has a pace count of 110 pace per 100 meters, was pace counter then he would have to walk (110 paces * 2.1938 = 241.318 paces) 241.318 paces 11 degress west of north to find the first marker. While Payden walked Sarah would stand at the starting point with the compass watching to make sure Payden didn't deviate from the 11 degrees west of north.
Discussion
Overall the exercise did not go as planned, Group 4 was only able to find 2 of the 5 markers. There are many reasons as to why this exercise was unsuccessful, the main one was the terrain of the Priory. The Priory is a 120 acre rectangle that is filled with large ravines, dense brush, thorns bushes well over 7 feet tall, and drastic elevation change. All of these less than ideal navigation obstacles made the traveling through the Priory very difficult. It was very easy for the pace counter to get off course walking around thorn bushes or thick trees. It was also equally difficult for the compass watcher to keep eyes on the pace counter for more than 20 to 25 meters at a time. Also the maps that were created used a 50 meter grid pattern to navigate with, this turned out to be two course of a grid pattern. When the locations of each marker was marked on the map there was a reasonable chance that the point could have been off by 20 meters or more. 20 meters is a significant distance when the forest was as dense as it was. Also the large changes in elevation made it especially difficult for the pace counter to measure the distance that was walked. The distance from one point to another on the maps is as a bird flies. The pace counter has to walk up and down different inclines that add numerous extra paces that threw off the distances. The final difficulty that was encountered was vandalism whether by animals or people certain markers were ripped off of trees. Marker number 2 was ripped off of the tree and laying a few meters away from it. Image 1 below shows this. The marker is pink tap that is laying next to the bottom part of the tree. Image 2 shows a tree with an intact marker, also featured below.
(Image 1: Marker ripped off of a tree)
(Image 2: Intact Marker)
To give an overall idea of how unsuccessful group 4 was at locating the markers, due to the variety of issues and obstacles that they ran into, a map was created that showed the location of all 5 of the markers and the path that group 4 took based off of the GPS unit that they carried. Figure 1 below shows this map.
(Figure 1: The Path of Group 4 in relation to the actual location of each marker.)
The data received by the GPS unit is not 100% accurate due to the large amount of canopy coverage by the trees. However it is easy to see that Group 4 never got close to points 3, 4, or 5 in the north. This is largely due to the fact that when marker two was ripped down they were unsure of where exactly to start when trying to find the third marker. So they missed all the rest by quite a lot.
Figure 2 below shows a map that contains all 6 groups and the the courses that they did.
(Figure 2: All groups and courses, color coded.)
Conclusion
This was a fun albeit difficult exercise that really demonstrated that if one part goes wrong the whole navigation can go wrong. It is better to simply retrace your steps back to a previous recognized point and start over from there. Also make sure that the grid used is an appropriate amount for the area that is being navigated. The Priory really needs a grid that is 25 meters or smaller. It makes it significantly easier to navigate.
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