Field Activity 3: Development of a Field Navigation Map

Introduction

This week's activity required us to create a field navigation map which we will use later in the semester along with a compass to locate specific points within the Priory in Eau Claire. We all produced two maps and within our groups of 3 decided on a single map to use while navigating around the Priory. In these two maps we used different coordinate systems including UTM and the more traditional geographic coordinate system of decimal degrees. In making these maps we had to balance the amount of information we put on it and the necessary information we will need for navigation purposes. We also were given a great deal of data which we needed to sort through to decide on which would be the most useful for navigating the Priory area. After determining which data to include and the proper way to organize such data we were able to produce useful navigation maps.

Methods

Our professor provided us with a various map data of the Priory in order to save us time and help us to better focus on making our maps. This data included both two foot contour lines (Fig. 1), five meter contour lines (Fig. 2), a DEM, a general outline of the area we would be mapping as well as an aerial photography of the Priory area. The aerial photo we were provided with was obtained from USGS as was the five meter contour lines and DEM. The two foot contour lines however were produced by UW- Eau Claire when they took a survey of the Priory land shortly after it was purchased by the university.

(Fig. 1) The blue lines display 2 ft contour lines in the Priory area in Eau Claire where the green box represents the navigational border of our study area.

(Fig. 2) The brown lines represent 5 m contour lines and the green box represents the navigational border of our study area in the Priory.

We were especially fortunate to recieve the contour data from our professor because it would be a complicated process. If we were to produce it ourselves we would need to extract data from the DEM and then save it as a seperate line feature to analyze. Once that was done we would need to make sure that all of the data is projected in the projection that we want. For this particular lab we used the UTM coordinate system instead of a geographic coordinate system in order to minimize the distortion of our aoi (area of interest) which is the Priory. In addition, the UTM coordinate system has map units which we can measure, this is very useful in the navigational purposes of this lab. The particular zone of the Priory area is UTM Zone 15 North. 

I did not face many issues with using the correct projection of the data in ArcMap because it was simple to correct the differences in the coordinate systems used by the various data sets. For instance, the five meter contour lines were in GCS North American 1983, the boundary for our navigation was in NAD 1983 UTM Zone 15 North, the aerial image was in NAD 1983 Wisconsin Transverse Mercator. Rather than using the on-the-fly projection, which uses the coordinate system of the first feature which is opened in ArcMap and then sets all the features brought into the program to the same coordinate system so they can all be viewed together, I simply reprojected all the data to the UTM Zone 15 North coordinate system. I decided to do this so that all of the data was in the coordinate system I wanted it to be in before I started to combine it and use them in creating my maps. 

After all the data was in the same coordinate system we began to start making our maps. Before starting to create my first map I opened up all the data files in a single ArcMap file to determine which data to include in my navigational map and what data to exclude. Once I viewed all the data at once I realized it was impossible to gain any real navigational information from the map because it was far too congested. After viewing all the data at once I decided to make my two maps showing different information and therefore serving two different purposes. I combined the aerial photograph with the five meter contour lines and the UTM coordinate system to produce my first map (Fig. 3). I made sure to also include an outline of the navigation area to show a more detailed view of what the parameters of our study area is within the Priory. I decided to include a fifty by fifty meter grid to use as a reference because I found that the five by five and ten by ten meter grids were unnecessarily small for the purposes of this map. Then for my second map I decided I wanted to show a better view of the elevation than just through contour lines. I used the DEM to show the elevation of the Priory study area and included the aerial photograph and the outlined navigation area (Fig. 4). I used the same fifty by fifty meter grid as a reference however displayed the map units in decimal degrees instead of meters in my second map. I added a scale bar, information on the coordinate system and sources as well as a north arrow to my map in order to properly offer the details necessary to use these maps for navigation purposes. 

(Fig. 3) This was one of my final maps for the navigation of the Priory. It includes the five meter contour lines with labels, the boundaries of the areas, utilized a grid system in meters and an aerial image of the Priory for reference.

(Fig. 4) This is the other map I produced which used DEM values rather than using contour lines along with the aerial image of the Priory as well as the boundaries of the area and a grid system in meters.

Conclusion

In creating our own maps we learned how much work goes into producing a navigational map. Not only does the cartographer need to decide which information is most useful and should be included in the map based on the purpose of the map but also must manage the various sources and data formats. Making sure that the data was projected in the same coordinate system proved to be an important factor in making these maps. In formatting the map it was important to include the least amount of information to keep the map simple but needs to include enough information to serve its purpose as navigation map. Later in the semester we will be putting our maps to the ultimate test though when we use them to navigate the Priory.