Field Navigation III

INTRODUCTION
This week, we expanded on the navigation exercises of the previous weeks.  A GPS unit was used to navigate to waypoints without the use of a map or compass.  Students were provided a list of Lat/Long points by the professor for each waypoint.  Students activated the tracklog feature of the GPS unit in order to track their route throughout the activity.

METHODS
To begin this activity, we had to find the starting point of our route, the location was indicated by the list of lat/long points given to us by our professor.  Our groups starting point was near the gazebo at the Priory.  At the starting point, we activated the tracklogs on the GPS units.  We made sure to activate only when we reached the starting point so only our course was tracked.  From the starting point, we used the lat/long feature of the GPS unit to navigate to the first way point (Figure 1).  We observed the increase and decrease of the lat/longs on the GPS unit to determine which direction to travel.  If we needed to go north, we would watch for the latitude number to increase; decrease for south.  To travel east we watched for the longitude number to increase; decrease to travel west.  This was done for all six waypoints on our course (Figures 2 & 3).  After we had found each waypoint, we traveled back to the starting point to complete the course.  Upon reaching this point, we turned off the tracklog.

Figure 1-Navigating with the GPS unit

Figure 2- Zac & Phil at the second waypoint

Figure 3- A waypoint in our course

Using the DNR Garmin application, students uploaded their individual tracklogs onto a computer.  Through this program, the tracklog could be easily converted into a point shapefile.  The shapefile was then imported into the class geodatabase.

Three maps were created for this activity; Class tracklogs (Figure 4), Group tracklogs (Figure 5) and individual tracklogs (Figure 6).

Figure 4- Map of the tracklogs for each student in the class

Figure 5- Map of my group's tracklogs

Figure 6- Map of my individual tracklog

DISCUSSION
Technology does not always make navigating easier.  Although we were allowed to use a GPS unit to navigate this week, it was not easier than the compass and map navigation.  It was somewhat difficult to determine the direction of travel using lat/long the the GPS and a group member had to be constantly watching the lat/long numbers to make sure we didn't stray off of our direction.  It was more difficult in my mind to navigate this week compared to last week, but it took our group less time to navigate using this weeks technique.

It is noticeable that the tracklog does not fit exactly with the waypoints.  This is because of the accuracy of a GPS unit and the tranformations from the GPS unit to a GIS shapefile.  This also skewed the starting and ending points of the course.  Even though our group walked to the starting points after the course was completed, the route is not "closed" according the the maps.

CONCLUSION

There are many techniques that can be used for navigation.  A map, compass or GPS unit are just a few of these techniques.  It is good to know how to use each of these individually as well as together.  A combination of these three techniques would allow for the must efficient and timely way to navigate.  GPS units are very accurate, but one must always observe the changes that may occur when transforming the data from GPS to a computer (GIS).  This can be avoided in some ways through a similar spatial reference for the GPS and the GIS.  If the data is still skewed, it can be manually edited in a GIS.

Field Navigation II

INTRODUCTION
This week we used the navigation maps from the previous exercise and applied our pace count to find waypoints at The Priory.  This straight forward exercise presented challenges due to the weather, terrain and lack of navigation technology.

METHODS
Before going out into the field our professor provided a list of X and Y coordinates of the waypoints (Figure 1).  We used these coordinates to plot the points on our navigation map (Figure 2).  We then used a compass to note the angle of direction on our map (Figures 3 and 4).  This information would be used in the field to better navigate the waypoint courses.  We also measured the distance in meters from one waypoint to the next.

Figure 1-X and Y coordinates of waypoints provided by Joseph Hupy

Figure 2- Waypoints plotted on navigation map

Figure 3- Angle of direction from point to point applied to navigation map

Figure 4- Zac plotting the angle of direction between waypoints on navigation map

We started at point 1A.  This was next to the dumpsters at the Priory.  We used our compasses to find the correct angle of direction.  We sent one person out about 150 feet and aligned their position to the necessary angle (Destination).  One person stayed behind to make sure the angle of direction was followed (Angler).  The other person walked while using their pace count to the person who was aligned with the angle of direction (Runner).  We kept track of how many paces it took for the runner to reach the destination so we could determine how much further we had to travel to reach our waypoint.  We broke up the distance between two waypoints so we could send out the destination person to an area where they were still visible to make sure we kept the correct angle of direction.  This process was repeated over and over to navigate through the course.  Once we reached a way points, we punched a course card given to us by our professor with the stamp at each waypoint.

DISCUSSION
Our group worked together very well and we each took turns being the destination, angler and runner.  We found it was easier for Phil and Zac to be the destination because in some areas I was too short so I couldn't travel far while staying visible.  The pace count was difficult to use in this exercise because we measured our individual pace count on a flat surface with no obstacles before this exercise.  We found that our pace counts came up short for each waypoint.  To overcome this, we kept our angle of direction and followed that direction until we found our waypoint.

We had to travel over a large, steep hill between points 4A and 3A.  Because of this, it was impossible to use our pace count.  We had navigated to 3 points before this section, so we had a good idea of how far we had to travel.  We estimated the distance we needed to travel and kept a very close eye on our angle of direction.

Another obstacle of this activity was the height difference between my group members and I.  I am about 6 inches shorter than both Phil and Zac, so I struggled to keep up with them because the snow was so deep in some places.  My group members understood why I was lagging behind them, so they slowed down for me. It is important while working in the field to stay and work together as a group not only for safety reasons, but also for accurate navigation.  The activity was also more fun because of the atmosphere we created as a group.

CONCLUSION
We found each waypoint quite easily using a compass, navigation map and pace count. The next activity is to navigate through the courses again, but without a navigation map or compass.  We will use a Garmin E-Trex GPS unit to find the waypoints and will track our log to see how precisely we can follow the path to the waypoints.

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.