Introduction:It is probably very far from most of our minds to think of using a map for navigation purposes beyond looking for exits for the nearest rest stop on a road trip. But, there are many occupations and recreational activities where navigating for something other than highway travel is helpful, and maybe even a necessity.
In such cases, providing users with accurate maps is of utmost importance. Imagine being guided off track in the woods during dangerous weather elements. Real situations like this exist and require map makers to consider the needs of users when choosing what to include and omit in a map.
This is not merely a matter of cramming every potentially useful piece of information into a map. Doing this would provide a very muddled picture to try to follow. The basic elements of map making, visual clarity, legibility, visual hierarchy, balance, and figure-ground are vitally important to consider in every map produced.
This activity requires making two maps for navigation. One map must be projected using the UTM coordinate system while the other must be projected using the world Geographic Coordinate System.
The Universal Transverse Mercator coordinate system divides the earth into 60 zones in six-degree bands of longitude (as seen in Figure 1). It is projected using a secant transverse Mercator projection
Figure 1: Map of the earth overlaid by the 60 UTM zones. Every zone spans 6 degrees of latitude using the secant transverse Mercator projection\
In addition, I will discuss the basics of navigation using a map and compass.
Professor Hupy provided several different data features we could choose to include in our maps. It was up to each student to decide which of these features would be the most helpful.
There were two sets of contour lines available to us (2 and 5 ft.). I chose to use the 2 foot contour lines because I felt that detailed elevation data would be important considering the varied terrain of the Priory Course.
Originally, I had planned to use an aerial image in my map to help orient myself to the area. However, after speaking with Professor Hupy, he mentioned that having a busy map ends up being more distracting and keeps you from being able to take good notes on your map. As a result, I chose to eliminate the aerial image.
In order to make sure that I stayed aware of the extent of the course, I included the Priory Course Boundary
The feature layers mentioned in Data Collection were combined within ArcMAP. For the first map, I chose the most appropriate projection, UTM zone 15, based on the location of our navigation course.
For the second map, I used the World Geodetic System (WGS) 1984. This is the standard used in cartography and navigation as well as being the reference coordinate system used by GPS.
Based on what Professor Hupy had mentioned about taking notes, I chose to include a note-taking section along with the other necessary map elements like a scale, north arrow, etc.
Each map needed to be displayed as an 11x17 figure with a landscape orientation. To do this in ArcMAP, Layout View was selected to display the maps. Then the following sequence was followed Change Layout --> North American (ANSI) Page Sizes --> Tabloid (ANSI B) Landscape.mxd (as seen in Figure 2). For this selection, the default setting is an 11X17 map with a landscape orientation.
The next step was to add the representative grids for meters and degrees to each map.
Figure 2: This figure shows the screen where the template to display your map as an 11x17 landscape oriented image is selected.
Next, I added the grids to each map in meters and degrees respectively. To do this within ArcMap, I remained in Layout View and followed the following sequence
Properties --> Grids --> New Grid
Then, within the Graticule Wizard, I chose Measured Grid (as seen in Figure 3).
Figure 3: Within the Graticule Wizard, you can choose which kind of grid you want to be included on your map.
From there you can move on to select a coordinate system within Properties. You will also be able to set the interval of your grid. For my map shown in meters, I chose a 50m interval on both the X and Y axis, and for my map shown in degrees I chose an interval of .00075 degrees on both the X and Y axis. For the latter interval, it took some trial and error to find the right interval.
Originally the numbers were shown inside the grid. This was hard to read as the numbers were displayed on top of the map. Within the Graticule Wizard, I adjusted the placement of the numbers so that they were on the outside of the grid. This made them much easier to read.
The following maps were produced using the methods above. The first map (as seen in Figure 4) shows the navigation course displayed in the UTM Zone 15 projection with a metered grid.
Figure 4: This Priory Course Navigation Map contains 2 meter contour lines, a navigation course boundary and a 50 meter interval grid
The second map (as seen in Figure 5) shows the navigation course displayed using the WGS 1984 coordinate system with a degree grid.
Figure 5: This Priory Course Map contains 2 meter contour lines, a navigation course boundary, and a .00075 degree interval grid
One method for navigating using the course maps I have created is a simple compass. While we will have the opportunity to use more sophisticated equipment in later exercises, it is important to be able to implement this basic method in the case of equipment failure.
A compass (as seen in Figure 6) will be used in our first navigation exercise.
Figure 6: This compass is almost an exact replica of the one we will be using in our future orienteering exercise.
To use the compass, you begin by placing it on the map of the area you will be navigating. The arrow seen at the top of the compass should be pointed in the direction of or toward the point you are trying to navigate to next.
Once this is done, rotate the bevel (rotating housing with degree dial) until ) 0 degrees on the bevel is pointing the direction of north as specified on your map.
Removing the compass from the map, you can now adjust your direction until the red end of the magnetic arrow fits into the hollow orienteering arrow. This position is referred to as "red in the shed."
As you move, make sure that you maintain this "red in the shed position. This will keep you moving in the direction of the point you are trying to reach.
Another useful tool for navigation is a pace count. By having a general understanding of your pace count you can keep track of the distance you have travelled from your initial point to the next point you are trying to reach.
To establish your pace count walk 100 meters using a consistent and comfortable stride. Simply count each step of ONE of your feet (not both). My pace count was 66 strides over the 100 meter distance which is fairly standard. Most pace counts will be in the 60s. To ensure accuracy, walk the distance 2-3 times and take the average of your pace counts from each trial.
One method recommended to us in our training was to break off a piece of a twig and put it in your pocket each time you walk 100 meters. If you become unsure of how far you have travelled you can just count the number of twigs you have broken off.
I avoided the temptation to include a lot of features in my map, namely an aerial image. This may or may not turn out to be a good idea. For a seasoned navigator, I assume it would be no problem. I cannot count myself as one, though. This may lead to difficulty in the field, if I happen to get lost/disoriented.
I am also unsure of the impact of 2 ft. contour lines vs. 5 ft. contour lines. If the 2ft. distance isn't useful, that I will have made my map busier for no reason. As I begin to think about the wide area of the course, I am apprehensive about my choice, and wonder if 5 ft. contours might not have been a wiser choice.
I spent some additional time talking with our trainer to make sure I understood the whole process of how to operate the compass effectively. This was not second nature to me. After going through the process a couple more times, I felt more confident that I would be able to carry out this process in the field.
Conclusion:Creating maps for navigation purposes must take into account several things. The things I noted were the level of experience of the person using the map, the overall area encompassed, the level of topographical change, and the need to take notes.
It is quite possible that someone with greater experience would desire an entirely different map than the one I would create for myself. Also, the size and topography are going to effect the ideal intervals used for contour lines and gridlines.
The key really is to make sure you are taking into consideration anything you can think of when preparing navigation maps. Over time, you will learn to ask better questions, and will better understand the needs of those using navigation maps. I would guess that, after going through the orienteering exercise, I will have added insight for creating my next navigation map.