Field Navigation IV

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 previous weeks, our class used different type of navigational resources to navigate through a newly acquired property for UW-Eau Claire, The Priory.  Maps, compasses and GPS units were used as navigational resources.  Students were put into groups of three and given a specific course to navigate.  Each group had to find waypoints in order to finish their course.  When the GPS units were used groups plotted points at the waypoints and a tracklog was used to note the course.  After we navigated the course in the field we used ArcGIS to import the GPS data and to create maps of our routes.

Each activity built on our knowledge of field collection.  The activities also introduced the students to other ways of navigating.  It was important for us to experience working in the field because we learned to overcome challenges that were presented by the weather, terrain and technology.

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

3.) 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.

4.)You have the class period to complete all 15 points from all three courses. The first group finished wins.  Make sure you use the punch on your cards at each flagged location.

METHODS

For the first weeks exercise only a map and compass were used to navigate The Priory.  Each student had to calculate their pace count before going in the field.  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 helped me to account for the distance I travel while navigating at the priory.

Two navigation maps were created for the first week's exercise.  The first map was an overview of the area (Figure 1), while the second was more precise and include topography (Figure 2).  Our professor supplied data included CAD drawings, aerial imagery and polygon feature classes.  Topographic data was also provided by the USGS.  The data was projected to NAD 1983 UTM Zone 15 North so a UTM grid could be applied to the maps.  A polygon feature class of the boundary was supplied by our professor as well as a point feature class of the waypoint locations.  This data helped us to reference our location in relation to the waypoints.

Figure 1- Overview navigation map

Figure 2- Navigation Map with 2 and 5 foot contours

When we reached The Priory on our first day of navigation,our professor provided a list of X and Y coordinates of the waypoints (Figure 3).  We used these coordinates to plot the points on our navigation map. We then used a compass to note the angle of direction on our map.  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 so we could use our pace count in the field to determine our distance.

Figure 3-X and Y coordinates of waypoints provided by Joseph Hupy

Once in the field, we started at point 1A.  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.

During the second navigation activity students were allowed to use a GPS unit and map to navigate the course.  To begin 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.  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 4).  We observed the increase and decrease of the lat/longs on the GPS unit to determine which direction to travel.  This was done for all six waypoints on our course.  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 4-Navigating with the GPS unit

Figure 5- Zac & Phil located a waypoint

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.  Once the data was imported, three maps were created.  One map showed the tracklogs for every student in the class (Figure 6).  Another map showed the tracklogs for my group (Figure 7) and another for my own tracklog (Figure 7).

Figure 6- Map of the tracklogs for each student in the class

Figure 7- Map of my group's tracklogs

Figure 8- Map of my individual tracklog

For the third activity, we used a GPS unit and map again to navigate to waypoints.  For this activity groups had to navigate to every waypoint, 15 in total.  We were also given paintball guns to add some excitement to the activity.    The same techniques were used as the previous week.  The same three maps were also created for this activity (Figure 9).

Figure 9-Week three maps: Class, Group and Individual Tracklogs

DISCUSSION

These activities taught me how different technologies can be used for navigation.  It is easy to assume the the highest techology is always best, but these activities showed me that it is possible to navigate accurately with simply a map and compass.

I also learned a lot about working together as a group through these activities.  Our group worked together very well, this helped our group to navigate efficiently.  One thing that did not work well for our group was using the pace count.  The pace count was difficult to use  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 in the field due to rough terrain and the amount of snow on the ground.

Technology does not always make navigating easier.  Although we were allowed to use a GPS unit to navigate in the last two weeks, 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.  Even though it was more difficult to navigate with a GPS unit, it took less time to navigate using this technique.

The transformation from the GPS unit to a GIS shapefile caused the features to be somewhat skewed.  Waypoints did not fall exactly in the correct location and the tracklogs were somewhat inaccurate as well.  This is one deterrence that is unfortunate but can be fixed through editing in ArcGIS.

CONCLUSSION

All of the techniques that we used to navigate were important in their own way.  It is important to know not only how to use these technologies individually, but also how to use the technologies as a combination.  We used techniques that are not technologically advanced (map, compass) and technologies that were advanced (GPS units).  The activities showed the benefits and drawbacks of each technique.