Introduction
Navigating in an area can be done in
several different ways. After spending the last couple weeks at the Priory, the
Geospatial Field Methods class has gained valuable navigation skills by
employing a variety of techniques. Although most navigation methods today are
incorporated with technology and are more accessible to the general public,
they may not always be reliable; therefore it is important to have an
understanding of both the technology part and using a basic topographic map. The
first activity called for the class to navigate in groups of three to a series of
waypoints at the site by using a compass and two topographic maps. The second
activity gave the class an opportunity to use a GPS unit and find a different
set of waypoints in the study area while the third activity used both the map and the GPS unit to find all points on the property. This report will include a description of
the study area, a breakdown of the methods for each technique that was employed
(map vs. GPS unit), the resulting track log maps, and a comparison of the two
methods.
Study Area
The Priory is located just south of
the Eau Claire, Wisconsin city limits on Priory Road. The former monastery
chapel used to be named Benedictine Hall until the UW-Eau Claire foundation
purchased the property to turn it into a new children’s center, which is now
called the Children’s Nature Academy. The 100 plus acre property adjoins
Interstate 94 to the north and is surrounded by a low density residential
neighborhood in rural Eau Claire. Although a large building that serves as the
daycare sits on the land parcel (Figure 1), most of the property is wooded and
hilly making it difficult to navigate to a particular point (Figure 2). The Priory also features a couple of ponds that lie next to the freeway,
which also provide another obstacle for the group to navigate around and
remain on course. With all of the different types of terrain that are found in
the Priory property, navigation techniques must be conducted carefully and
accurately in order to find the set of waypoints.
Figure 1: The Priory, Eau Claire, Wisconsin
Figure 2: Wooded Terrain at the Priory
Methodology
Navigating
around an area requires a significant amount of preparation and knowledge of
using the various instruments for each technique. The study was split up into
three separate activities, which gave the class an opportunity to work in small
groups and navigate to five specific locations in the Priory first by using a map/compass
and then with a GPS unit for the following week’s exercise. The third activity
at the Priory involved using all three instruments to locate all points in the
property. This project will detail the methods that were applied in each
exercise of navigating the Priory.
Field
Navigation Map and Compass
Before
one can navigate in an unfamiliar area, preparation and development of two
field navigation maps must be created. These maps were created in ArcMap using
the feature classes in the Priory Geodatabase, which was provided by the
instructor. The first step is to bring in the aerial image of Western Eau
Claire in the GIS and clip it to the Priory study area using the navigation
boundary feature class. Having an aerial image as a basemap under the contour
lines will help with the navigation exercise for the following week when the
class visits the study area. The next step is to bring in the 5 meter contour
lines that will go over the aerial image. Since ArcMap does on the fly
projection, it is easy to forget about what the projection and coordinate
systems are for each feature class. It is important to note that each feature
class that was given to the class has a different projection. The 5 meter
contour line feature class is projected in GCS North American 1983; the aerial
image of Eau Claire has a projection of NAD 83 Wisconsin Transverse Mercator;
the navigation boundary feature class has a projection of NAD 1983 UTM zone 15
North. Although all of these feature classes have a different projection, they
all line up with each other in ArcMap because of on the fly projection.
When the 2 meter contour line map was created, the
projection and coordinate system became an issue because none of the feature
classes would overlay or match up with that particular feature class in ArcMap.
The data for this feature class is based on a UWEC survey, which was converted
from AutoCAD files. Since the data source for the feature class displays an
undefined coordinate system, the 2 meter contour feature class has no spatial
reference and cannot be lined up with the pre-existing data that have a defined
projection in ArcMap. This poses a problem for navigating because the contour
lines need to overlay the study area in the same projection to ensure that the
results are more accurate. To fix the problem, our class started a new screen
in ArcMap and brought in the clipped aerial image into the design view and then
the 2 meter contour line feature class right after it. After doing this, our
feature classes were able to match up with on the fly projection. If this was
not done, our lines could have been significantly off on our navigation maps
and give us inaccurate results of finding the exact point locations. The root
of the problem is to make sure that all of the files are projected the same.
The next method is to set the grid in layout view
in ArcMap for every 20 meters. The 20 meter interval will be used on the
navigation map because the 10 meter interval made it too hard to read the
contour lines on the map because it is so cluttered with information and lines.
Going any higher than 20 meters will also make it hard to pinpoint the location
of the points that need to be found in the study area.
Another important step is to set the grid to NAD
1983 UTM Zone 15 North. Using UTM coordinates for navigation makes it possible
to measure distance especially for the small study area. Once this is complete,
the field navigation maps can be created using the 5 meter contour line
intervals and the other using the 2 meter intervals in ArcMap.
Figure 3 shows the map with the 5 meter contour line intervals. An aerial basemap is placed underneath the contour lines so that the group can find their location on the map relative to the features at the actual site. The 5 meter contour interval allows for a basemap because it is not as detailed as a topographic map with 2 meter contour intervals. Figure 4 shows the map with the 2 meter contour line intervals, which does not include a basemap for the sake of reducing the clutter of detail on it and keeping its function for navigation.
Figure 3: Priory Navigation Map with 5 Meter Contour Line Intervals
Figure 4: Priory Navigation Map with 2 Meter Contour Line Intervals
The
materials needed in the navigation activity include the following: magnetic
compass, 5 meter contour lined map, 2 meter contour lined map, punch card, and
the list of waypoints for the assigned course. Since the points provided by the
instructor are in UTM, it is essential to have the grid coordinates in UTM on
the navigation map. One of the maps that the group picked did not have these
coordinates making it useless on the day of the activity. Fortunately all of the
other groups had UTM coordinates on their grid and my group was given a usable
map for the navigation exercise. The class was also given a refresher on how to
use a magnetic compass for navigating in the field.
Once the materials are gathered for
the navigation exercise, the waypoints can be plotted on the map according to
their given UTM coordinates (Figure 5). The instructor created 3 courses around the Priory property for each group to
go out and punch in at 5 specific locations throughout study area. My group was
assigned course 2, which included trekking over different levels of terrain
between each point. Since the map that the group used had a 20 meter grid, each
member checked to make sure that the points were accurate enough before moving
on to the next step.
Figure
5: Plotting Course 2 Points on the Navigation Map
The next method is to find compass
bearings between each set of waypoints on the navigation map. Straight lines
were drawn between the points so that the compass can be aligned in the exact
direction of the next point on the list. Using the magnetic compass, one can
take the direction of travel arrow and align it on the line between a set of
points. For example, we took the compass and placed it on the map aligning it
with the line between the starting point and the first point on course 2. This
method was done for each plotted point on the map. We then had to move the
compass house with degree dial until the “N”, which indicates north, points to
the top of the navigation map. The top of the map for this study is assumed to
be true north and is closely lined up with the tilted vertical gridlines. Once
the “N” is pointed to top of the map, the group can look at the index line
where it says “read bearing here” and record it so that it can be used to find
the next point. These bearings will help us in the field once we get to a
specific spot by showing us the direction that we need to face to reach the
next point.
Another method is to measure the
distance between each point on the map using the scale bar and a piece of paper.
We discovered that one of our group members has a consistent pace count of 65
for every 100 meters. Knowing the distances between each point will give us an
idea how far we will need to go before looking for the landmark point on our
list. The deep snow and rough terrain, which includes steep hills and thick
forests, may throw off the consistent pace count making it necessary to add
15-20 steps for every 100 meters.
The second last method is
designating the roles for each group member while navigating in the field. We
had one person (me) manipulate and hold the compass according to the bearings
and face in the direction of the point on the map. Since there were many steep
hills and fallen trees in the way of each point, a second person (Hannah) was
responsible for moving to the landmark in the direction dictated by the person
holding the compass (Figure 6). This allowed for each trek between the set of points to be done in segments and
ensure better accuracy in the direction of travel. Once our group member
reached the landmark in the direction of the compass holder, the other person
(Kory) did the pace count to that spot. Kory would add to his pace count until
the group reached marker for our next point (Figure 7).
Figure
6: Group Member moving to designated landmark in the distance (dictated by
compass holder)
Figure
7: One of the Markers in Course 2
The last method is to go out with
the group to navigate and collect punches at each point on course 2. This
required good communication between the members to ensure that we were heading
in the right direction and finding ways to overcome obstacles along the way.
Both the 2 meter contour and 5 meter contour line maps were utilized in this
activity because each included features that were helpful in navigating to the
destination points. One map had an aerial basemap under the lines, which made
it easy to tell where we were on the property of the Priory and whether or not we
were getting close to a plotted point.
Navigating
with a GPS Unit
The
ability to navigate easily in an unfamiliar area or region is made possible
through new technology such as a GPS. This instrument allows people to pinpoint
their location and navigate to the location that is desired without needing
timely preparation that is associated with a map and a compass. This activity
called for the class to divide in the same groups and navigate to 5 different
points in the Priory property using a GPS unit.
The
first method is to check out a Garmin etrex legend H GPS unit from the
geography department at the University of Wisconsin-Eau Claire. This GPS instrument
provides accurate coordinates of where the person holding the device is
located. Once the GPS is obtained, it is important to learn how the track log
function works on it before going out into the field. To get to this screen,
turn on the device by pressing the on button located on the right side and
second one down. Next press the top right side button twice to get to the track
log screen where it gives the option to turn the track log on. Any stored track
logs in the device from previous users should be erased so it shows only the
data for the navigation activity. The track log should also be turned on once
the group arrives to the starting point of their assigned course in the study
area.
The second method is navigating to
the starting point of the course that the group was assigned. Since my group
did course 2 last week, we had to navigate through course 3 this week denoted
with a “b” after each number in Figure 8. Finding the starting point was not an easy task as our
group was provided with a GPS and a list of coordinates in UTM that we had to
navigate to. Fortunately, the GPS is also equipped with a compass screen, which
helped us decide the direction of travel our group needed to move in order to
reach the desired coordinates on the list. The group noticed that as one moved
to the east, the X UTM coordinates increased and the same occurred with the Y
UTM coordinates as one moved to the north. Ultimately, we decided to focus on
getting to the Y UTM coordinate first and then move east or west to the X UTM
coordinate depending on our location from that point. Once the group reached
the last point on the list (6b), we turned off the track logs on the GPS.
The third method is to upload the
track log points as UTM NAD 83 in the DNR Garmin program. These points can then
be imported to a Geodatabase in ArcMap as a point feature class and projected
to NAD 83 UTM zone 15N if necessary. ArcMap is used to show the path of the
track logs on a map of each individual group in the class.
The last method is to create three
maps showing all of the class track logs from the exercise. Figure 8 shows my
individual track log (track log 27), which follows course 3 going from 1b-6b
sequentially. Figure 9 includes the track logs of my group on the same course. Lastly, Figure 10 displays the track
logs for the entire class and covers all three courses in the study area.
Figure
8: Track Log 27 Course 3
Figure 9: Group 3's Track Logs Course
3
Figure 10: All Geography 491 Field Methods
Class Track Logs
Implementing
both Navigation Techniques in the Priory
The third week’s activity allowed
the class to navigate using both techniques from the previous two weeks in the
same groups. Since each group member was equipped with a map, compass, a GPS
unit and a list of waypoints, this activity’s objective was to locate and track
all fifteen points in the Priory in a strategic way because it was a race
against the other groups. With this challenge accepted, my group decided to
rely more on the navigation map from the first activity and have the GPS unit
ready in case our location was far from the destination set of coordinates.
Exploring the property for the third time helped with this navigation exercise
because the class became familiar with the land and the general location of the
waypoints. Nevertheless, we utilized both the map and the GPS unit repeatedly
throughout the course to find the specific points. Each group member had to
keep a track log throughout the navigating exercise and record a waypoint once
arriving to a marker indicating a destination point on the map. Figure 11 displays my track
log for this exercise with the starting point at 1a. Points 1 and 1b did not
have to be recorded because of being located in the restricted zones. Although
my group only found thirteen of the fifteen points on property, it would have
taken longer if we were not equipped with a map and a GPS unit. Figure 12 shows my group’s
track logs, which show a similar path to mine. Figure 13 displays all of the track logs from class
and clearly shows the different paths that other groups took to reach the
points.
Figure 11: Track Log 27- All Courses
Figure 12: Group 3's Track Logs- All Courses
Figure 13: All Geography 491 Field Methods Class Track Logs
After starting out at point 1a in Figure 12, my group headed
for point 6b and round the property ending with point 2a. The methods of finding
each point are the same as the ones in the first two exercises, however there
was more of a reliance on the map and GPS unit than on the compass. My group
also utilized land features such as the edge of a forest to locate the markers.
Between points 4b and 5a, we used the border of the evergreen forest to go in
the right direction. The coordinates on the navigation map and aerial imagery
helped speed up the process of moving through the Priory course.
Discussion
When comparing the track logs from Figures 8 and 11, it is evident
that the track logs from the final activity are going in a straighter and more direct
direction towards the points. One reason for this is that the Garmin GPS unit
only showed the UTM X and Y coordinates and cardinal directions, whereas the
map displayed all of that along with aerial imagery and other terrain features
such as elevation. It is important to know that when navigating with a GPS unit
in UTM coordinates that the X coordinates increase moving to the east and the Y
coordinates increase going in a north direction. Having a map helped my group’s
navigation abilities in this exercise and also sped up the process of
completing most of the course. As aforementioned, the map’s aerial imagery gave
us a better idea of what my group needed to look for in the terrain and what general
direction they had to go to reach the next point.
The first navigation activity with a
topographic map and a compass reduced the dependence on technology to do the
navigation for us. Although this navigation method is not as easy as it looks,
we found that it is fairly accurate and led us to find the points on the map
without too many issues. The two meter contour line map was an advantage for us
in this exercise because it showed us the type of terrain in our direction of
travel. Not only could we see that there was a steep hill in front of us, but
the map also confirmed a steep change in elevation ahead. The aerial basemap
was also beneficial to finding the location of these points by helping us see
if we had to go through a dense forest of evergreen trees or around a large
pond. The other advantage of our preparation before going out to field was
plotting the distances we needed to travel in 100 meter intervals. This gave us
an idea of how far it was to the next point while taking into consideration the
pace count of the walker.
Although there are many advantages
to our navigation maps in this exercise, one disadvantage is the difficulty of
being able to read the map with the 2 meter contour lines because it also
included the aerial map. The next navigation map should have a more transparent
the aerial map so that it is easier for even a non-geographer to read and
navigate with. Another obstacle we faced while locating the points was trying
to maneuver around the ponds near the freeway. Since this land feature was in
the direct path of one of our points, we had to go around it and estimate
Kory’s pace count once we got to the other side. It was difficult to use the
pace count to measure our distance because we established what our pace count
was in a parking lot that was cleared free of snow. The last disadvantage was
our attempt to move in a straight line through the deep snow and thick forest.
Even though it is winter and the trees are not filled with much vegetation,
there are many fallen down logs and small trees that got in our way. We were
able to overcome this by designating a visible landmark in the distance that
connected with our path and have that as a meeting point before moving on.
Overall, the last activity with both
the map and the GPS unit went the fastest. As long as the maps are detailed and
contain essential information such as the coordinates in UTM, aerial imagery,
contour lines, and the course point location, it can serve to be a great
resource alongside a GPS. After navigating with both techniques through the
Priory, it is evident that a GPS and a navigation map can navigate successfully
separately, but are more effective when used together.
Conclusion
The field navigation exercises
helped improve my navigation abilities in the field by learning about three
different methods: navigation with a traditional map and a compass, GPS unit
navigation, and navigation with a GPS unit accompanied with a traditional map.
Although the last technique proved to be the fastest and most efficient way to
navigate around a plot of land, the GPS unit is also quick at finding a set of
coordinates. The slowest method out of the three was the first one where my
group used a map and a compass to navigate. Even though it is a time consuming
way to locate a particular point, it does not rely on technology and can be
helpful if we did not have that luxury at hand. It is important to have an
understanding of the many navigation methods that are available especially when
there is travelling involved in conducting field work.
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