Introduction
The focus
of this exercise is on navigation, and the importance of coordinate systems for
a successful project. In order to gain a greater understanding of what makes a
good navigation map, students were asked to prepare 2 maps, each with a
different coordinate system to use during the exercise. The task at hand is to
successfully navigate, through a dense forested area to several waypoint
locations throughout the property.
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| Figure 1: Displaying parts of greater Eau Claire. Image taken from Google. |
The location for this project is the
University owned land, a few miles south of the city of Eau Claire. The land
mostly consists of coniferous dominant forest, with a few patches of birch tree
intermittently. There is also a large complex of buildings, with a field
located north of the buildings. The land has areas of relief encompassing the
field to the north of the buildings.
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| Figure 2: Image of the University owned lan. Provided by Google. |
Building a
map that is designed specifically for the task of navigation is a much
different process then designing a map for display in a book, or online. A
different set of criteria is necessary to keep in mind when designing a
navigation map. For example, if a map if going to be published in a book, the
author will most likely be using the map as a image to help illustrate, or
provide proof for a point which he/she wish’s to assert. This means that the
map will probably use visual cues to sway the reader into the mindset of the
author. Visual cues are often strongly associated with certain color selection,
and also items in the map that may be selectively displayed or omitted. This
may lead to a more dense, and comprehensive map, but does not help with
navigation of any sort. On the other hand, when creating a navigation map,
making a dynamic map, that gives a visual representation of the landscape,
while providing no extra or unnecessary information to confuse the map user.
Navigation maps are usually fairly barebones, but when working in the field,
simplicity is king. Having a simplistic map, that displays all pertinent information,
allows the user a more streamline reference system on which to navigate from.
Background
on UTM: Establishes a grid that is constant throughout the map. The coordinate
system also allows for a number system to directly relate to a distance
measureing system. UTM is great for mapping at various parts of the world,
since it has a consistant measuring system.
Decimal Degrees: Uses latitudinal and longitudinal coordinates
and divides them into decimal degrees. This results in in negative, and
positive values for lat. And long, and is bound by a +-90 and +-180
respectivly.
Methods
Constructing
a navigation map requires the map technician take a holistic approach when distinguishing
what features to include in the map. For this exercise, two maps are required
of the same zone. One map will have a UTM grid, while the other will have a
geographic coordinate system grid.
First, a
database is created in an accessible folder for this project. The data is copied
from the original university run database, and pasted into the newly created folder.
Careful inspection of the files is needed, as they are all projected into
different coordinate systems. It is recommended that each file that is going to
be used is projecting into one coordinate system that will be used for the entirety
of the project.
To produce
the map featuring the UTM grid, data was gathered from the University of
Wisconsin Eau Claire data file. The data contained a topographic lines feature,
a boundary line of the university owned land, several LiDAR files that can be
processed into raster files, and an iconographic representation of the
landscape. Next the elements that present the most use are added to the Arcmap
window. Given the parameters of this project, I choose to make the UTM grid map
to feature a topographic representation of the landscape (figure 3). The topography was
illustrated using a 2m contour line, in a light gray color. The backdrop
features a dark colored outline of the university owned land. Once the map is
visually comprehensive, change the screen from data view, to layout view.
Clicking on the “layers” properties button, a menu is brought up. Selecting the
Grids tab, a variety of selection menus and specification menus can be accessed
to customize the grid format for the project. Here the grid is edited to fit
the desired need of the project. For the area if interest for this project, has
a relatively large scale, so the first set of numbers in the Mercator numbering
system do not change over the course of the study area. This means that they
are functionally irrelevant, and can be omitted by turning the color to light
gray, and making the font size very small. This accents the second portion of
numbers, which contains a metered system that will be most useful while
navigating by foot. The grid was scaled down to show lines every 20 meters.
Another final is to add a north arrow, to help orient the user when viewing the
map in the field.
The next
map to be made, Figure 4, will feature a grid system using a GCS measured in decimal
degrees. A similar process of thought to the first map is implemented. This
time an aerial view with a false coloring is added to the map. Another layer is
added on time of that, which features different style topography then the first
map. The topography layer is then edited under the “display” tab of the
“properties” to be 65% transparent. This allows several distinct features from
the aerial image to be seen, along with faint topography lines displaying the
elevation of the area. Having the aerial image gives a great guideline for the
buildings and location of the forest features, with the combined element having
topography lines to help add distinction to the hills. Similarly to the first
map, the data frame is switched to “layout view” and a grid is added. This time
the units used are decimal degrees.
Results:
Figure 1:
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| Figure 3: UTM coordinate system Navigation map. Units in meters. |
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| Figure 4: Navigation map number 2 with the GCS in decimal degrees. |
Discussion:
Building a
navigation map requires a depth of knowledge on a variety of topics. The mapmaker
must be essentialist about the features of the map, in order to provide a
dynamic map that is not over cluttered. Background knowledge of coordinate
systems and the ramifications of using different systems are very important to
a successful outcome of a project. Understanding the units involved, and when
appropriate times to use each coordinate system will save much time later down
the road. For example, using a CS that displays decimal degrees will not be
very helpful when navigating on foot, without a GPS. A reason for this is
decimal degrees do not divide neatly into the measuring system, with 1 D.D.
equaling approximately 44 feet. This makes calculations clunky, and wastes
valuable time. However, using a map that displays D.D would be helpful when
using a GPS. Since the last portion of this project involves tracking the route
our group takes to get to each waypoint, producing a map with D.D can be
helpful. Additionally, producing a map
for use on foot, without a GPS requires units in easily divisible numbers, in
this case meters. The map that will most likely be more helpful for the act of
navigating will be the UTM grid, which displays the information in meters.
The second map (figure 2.) that was produced for this
project is clunky, and quite confusing and ugly. If a better map were needed
(not provided by partners), it would have been better to further process the
LiDAR data into a surface elevation model, and add a grid on top of that. But
for the sake of time, a less quality version of the map was produced.
In summation, producing navigation
maps requires a keen eye, and a thoughtful process that takes into account
possible problems that may occur in the field. Along with knowledge for
coordinate systems and grids, a successful project outcome will be facilitated.
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