Navigation with a Map and Compass

Introduction
The objective for this week's exercise was to navigate through the woods to a series of points using a map and a compass.  This exercise is the follow-up activity to last week's prep work, consisting of the creation of maps and the establishment of each person's pace count.  

Methodology
The preparations for this week's field activity took place last week with the establishment of a pace count and creation of maps of the area of interest.  To establish each student's pace count, 100 meters was marked off in a parking lot.  We then walked the distance and counted the number of paces it took.  I walked the distance three times, and had a consensus pace count of 65.  Maps were then created of the area of land around the Priory using a variety of data sets (Maps 1 and 2).

Map 1. Priory Navigation Map with DEM and Two-Foot Contours

Map 2. Priory Navigation Map with Orthophoto and FiveMeter Contours

As a group, we chose to use Hannah's map in our navigation exercise (Map 3), as well as Map 2.

Map 3. Hannah's Navigation Map

 The field event took place the following week on March 4th.  A snowstorm was moving into the area, but there were only a few flurries during the exercise.  As previously mentioned, our goal was to navigate to five different points using a compass and the maps that we had created.  The first step in the process was to plot the points on our maps using the UTM coordinates that were given to us.  In attempting to do so, it was evident that the grid that Hannah put on her map was not correct.  This put our group in a quandary because there was no way for us to plot the points.  Luckily, we were able to use another group's map.  After the points were plotted on the new map that was given to us, a straight edge was used to draw lines connecting each of the points.  These lines were used to calculate the bearing.  To do so, the compass was placed on top of the map facing the direction that we wanted to travel.  The dial on the compass was then turned so the lines were facing straight up to the top of the map.  This process was completed for each of the five points on the course we were given.

Image 1. Mitch and Hannah Plotting Points

The scale on the map was then used to draw an estimate for the distance between each of the points.  This would prove to be very useful in the field because we could use our pace count to estimate how much further we would have to navigate.

Map 4. Approximate Location of Navigation Points

After our points were plotted, and the bearing and distances were calculated, we set outside to begin our navigation.  We went to our starting point and were to navigate to the designated points where there was an orange marker and a paper punch to show that we made it to each point.  Our method of navigation began with Mitch using the compass and dialing the bearing that we had calculated earlier.  He would then have Hannah walk to a spot (usually a specific tree) on that bearing.  I would then walk in a straight line to Hannah and count the number of paces to provide us with an estimated distance traveled.  We continued this process until our destination was reached.  Image 2 and 3 depict Mitch standing next to the first marker and directing Hannah to a tree on the bearing to our second point.

Image 2. Point Marker 

Image 3. Hannah Walking to a Tree

Discussion
Overall, the navigation event went very well for our group, as we were able to utilize a method that allowed us to move to the points quickly and efficiently.  However, there were a couple minor issues that we had to overcome.  The pace count that we established was done in a flat parking lot, and was not very conducive to estimating accurate distances when walking through the woods.  There were many hills that we had to walk up and down, as well as many trees and other obstacles that made walking in a straight line difficult.  When walking between points four and five, we came across some ponds that were fenced off.  In order to accurately maneuver around them, we counted a number of paces to the side of them.  Once we were around the ponds, those same number of paces were walked sideways to get back on the correct bearing. As mentioned earlier, we also the grid issue on Hannah's map that did not allow us to plot the UTM points.  Experiencing this shortcoming has stressed the importance of reviewing every detail before going out in the field.  

The maps that we prepared were great resources in the field.  The aerial imagery was very helpful in determining what type of terrain we were in and should be going to.  The DEM symbology and contours were also useful for tracking our progress on the map.  We had to walk up and down a few hills, and this information allowed us to make an accurate estimate of our location in terms of the points we were navigating to.  The point data we were given had the elevation in meters listed, and Map 2 that I created was useful because the five-foot contours were labeled.  For future navigation exercises, I would create maps very similar to the ones that we created for this event because the information we included on them was very helpful in the field.  One change would be to include the grid on both maps.  When making a map, it is important to have all of the data layers in the same coordinate system to insure accuracy.  Finally, making sure the correct grid is used is essential.

Conclusion
The navigation event conducted at the Priory went very well for me and my group.  Once the points were plotted on maps that were created, a compass was used to calculate the bearing in which to walk to successfully locate the next point.  Distances were also estimated and related to pace counts that had been previously established to approximate how much further we needed to travel to find the point.  We were able to effectively navigate to the points via teamwork and the information that was included on the maps.   The one main issue we encountered was the inaccurate grid that did not allow us to plot the points on the maps that we had.  This was an example of learning the hard way that all details and information should be carefully evaluated to ensure the greatest possibility of success in any line of work.