Developing a Field Navigation Map

Objective
The goal for this lab was to create a cartographically pleasing navigation map to be used for a future project at the Priory, a parcel of land owned by UW-Eau Claire.

Introduction
Navigation maps require a different set of characteristics than a normal map. Since they are used for finding one's way around, a location system of some sort is necessary such as a coordinate system and a projection. A coordinate system assigns a system of numbers used to define locations in the field, and a projection takes longitude and latitude and converts them into an XY coordinate system. In this lab, the Universal Transverse Mercator (UTM) coordinate system was used for one map (Fig. 2), and a Geographic Coordinate System (GCS) was used for another map (Fig. 3) so that the two could be compared in terms of which one is most useful and easy to understand.

Methods
This lab involved two parts: finding a personal pace count and the creation of the navigation maps.
Part 1: Pace Counting
To determine a personal pace count, a distance of 100 meters was measured out and each person counted the steps they took with their right foot along this distance (Fig. 1). (My personal pace count is 63 steps per 100 meters). This was repeated twice for accuracy.

Figure 1. Study Area for pace counting.

Part 2: Developing the navigation maps
Two maps were created for part 2: one containing a UTM grid at 50 meter spacing, and the other providing Geographic Coordinates in Decimal Degrees. The data used to create these maps was provided by the UWEC Geography Dept. The first step was to import the basemap containing aerial imagery of the study area into ArcMap. The the study area was identified by a layer provided by the UWEC Geography Dept. showing the boundaries of the Priory. A contour layer showing elevation in 5 meter increments was added as well because elevation is important in navigation. The contour layer was clipped to show contour lines only inside the study area to make the map look more neat. The aerial basemap was reduced to a 30% transparency for cartographic reasons as well. Then, in order to make sure all of the layers were in the NAD_1983_UTM_Zone_15N coordinate system with the Transverse Mercator projection, each layer had to be reprojected using the project raster tool. To add the grid system to the map, a new grid was created in the data frame properties. For this UTM map the grid was a measured grid with 50 meter spacing (Fig. 2)

For the GCS map, the basemap imagery, elevation contours, and study area layers were all reprojected into the GCS_North_American_1983 coordinate system and the measured grid was removed and a graticule grid was added with decimal degrees showing 4 decimal places (Fig. 3).


Results

Figure 2. UTM navigation map of the Priory with a 50 meter interval grid and 5 meter elevation contours.

Figure 3. GCS map with decimal degrees and 5 meter elevation contours.

Conclusion
The UTM map is a little bit less cluttered because the intervals of the grid are larger, however this causes a lack of precision when navigating. Both maps are good for different purposes. The GCS map allows for closer navigation while the UTM map is better for approximation and less detailed surveying. The UTM map is also easier to understand for someone who does not have a lot of navigation experience because it is measured in meters, while decimal degrees may not mean a whole lot to someone who has never learned how to reference them.