Navigation Map I

INTRODUCTION
Navigation in the field is incredibly important in field methods.  Accuracy in the field is dependent on the type of navigational resources available and can be skewed with the simplest miscalculation.  In the upcoming weeks, our class will be navigating through and plotting waypoint locations at the Priory, a newly acquired property for UW-Eau Claire.  Before we can set out in the field, we had to create a navigation map and determine a pace count for our group.

METHODS
To navigate in the field, each person had to calculate their pace count.  A pace count takes into account how many steps a person takes within a given distance.  This information allows a person to know how far they have traveled without the use of a GPS unit.  The distance for our pace count was 100 meters.  To determine my pace count, I walked at a normal pace counting every pace (every other step) for a pre-measured distance of 100 meters.  I repeated this process three times and took the average of the count-70 paces.  Knowing my individual pace count will help me to account for the distance I travel while navigating at the priory.

We will use two navigation maps locate our positions while in the field.  The first map will be an overview of the area, while the second will be more precise and include topography.  The maps will be printed on 11 X 17 sized paper, so before we could begin, we had to change our paper setting to match.  Our professor provided a wealth of data in the form of a geodatabase to use in our maps.  The data included CAD drawings, aerial imagery and polygon feature classes.  Topographic data was also provided by the USGS.  Maps can hold a wealth of information, but too much can cause confusion for the map user.  This was a challenge in the creation of our navigation map.  Although we wanted as much information as possible, we also need to be able to easily read and use our map.

I used an aerial image of the study area (The Priory) as the background of my first map (Figure 1).  I applied a topographic line feature class of 5 foot contours from the USGS as the next layer of the map (Figure 2).  I negated the 2 foot contour lines of the CAD drawings for this map to avoid clutter.  This first map will be used for an overall locator, so precision wasn't the highest priority.  The next layer of the map was a polygon feature class showing the boundary of the waypoints in the study area (Figure 3).  This data was also provided in the geodatabase.  The rectanglur polygon feature class had to be projected to the NAD 1983, UTM Zone 15N to correspond to the other map layers.

Figure 1- Aerial image of the study area (The Priory- Eau Claire, WI)

Figure 2- Aerial image with 5 foot contours and labels

Figure 3- Waypoint boundary polygon

A UTM coordinate system grid was applied as the top-most layer of the map.  This grid can be created in ArcMap by choosing "Data Frame Properties"> "Grids" and creating a new grid (Figure 4).  The spatial reference of the grid had to be set to NAD 1983, UTM Zone 15N (Figure 5).  Other grid properties were customized for visual necessities and units of measurement (Figure 6).  Figure 7 shows the UTM grid that was applied to the first map.

Figure 4- Creating a new UTM grid

Figure 5- Grid units

Figure 6- UTM coordinate system spatial reference

Figure 7- Newly created UTM grid with 50 meter units

 Once the map and UTM grid was created, other pertinent information was applied.  This information included a north arrow, scale bar, the projection and coordinate system of the data and data sources.  Figure 8 shows the final product of the first overview navigation map.

Figure 8- Overview navigation map

The second navigation map was created to have more precise topographic data.  The same data was used as in the first map, but I added a CAD drawing provided by the professor.  The CAD drawing consisted of 2 foot contour lines.  This was the "bottom-most" layer of the map and the same 5 foot contour data layer was applied as the next layer (Figure 9).  The symbology of this map was critical to ensure the visibility of both the 2 foot and 5 foot contours lines.  The 5 foot contour line data was labeled as a reference to the elevation.

Figure 9- 2 foot contour CAD drawing with 5 foot contour data layer

After applying both contour data files, the polygon of the waypoint boundary was again placed on the map (Figure 10).  The UTM grid was applied once again as well with the exact parameters as the first navigation map (Figure 11).  The same reference data was also applied including the projection, coordinate system, study area, data sources, north arrow and scale bar.  Figure 12 shows the second navigation map for more precise topographic representation.  The aerial imagery was not used for this map so the contour lines would be more easily visible.

Figure 10- Boundary polygon with contour data

Figure 11- UTM grid with 50 meter units

Figure 12- Navigation Map with 2 and 5 foot contours

DISCUSSION

Although the process of creating navigation maps seems quite simple, the importance came from the application of data.  The maps needed to present all necessary information, but ease of legibility was also critical.  By using two maps this asset could be maintained.  Each person in our group of three created their own two navigation maps and we voted on the best maps to use in the field.  We chose Zac Womeldorf's two foot contour map (Figure 13) and Phil Glodowski's aerial locator map (Figure 14).

Figure 13- Zac Womeldorf's 2 foot contour map

Figure 14- Phil Glodwoski's Aerial locator map

CONCLUSSION

Knowing how to find data and knowing what the data represents is critical to map creation.  Aerial imagery can be found using NAIP imagery or Google imagery.  The USGS hold a wealth of topographic data, but it can also be found from other sources like the Wisconsin Department of Natural Resources.  GIS data is available from numerous sources, but it is best practice to use data that complies with National Map Accuracy Standards.  These standards ensure that the data creator, data lineage, projection and other pertinent information are provided with the data.

It is important to know how to navigate using a pace count and how to create a navigation map because these techniques do not require a high level of technology and they can be used in a variety of data collection methods.  The maps will help us to locate our position at The Priory and to navigate while collecting waypoint data.  They will also serve as a base for the creation of our next maps that will include waypoint data points.