Development of a Field Navigation Map and Learning distance/bearing Navigation

Introduction

Later this semester, our class will be going out to a place called the Priory, where we will practice navigation. The Priory is a peice of land owned by the University of Wisconsin Eau Claire that is located a couple of miles away from the main campus.  As we did not actually go to the priory yet, I will leave a more complete and detailed description of its location for another blog post.

The main objective of this lab, will be to produce maps that our groups will be able to use during that navigation activity.  The maps that we are producing are navigation maps.  All maps are designed to convey some meaningul information, the information displayed on this map will ideally be useful in navigating.  For this reason, I will be careful in this lab, to not put information on the map that is not helpful in navigation.  Any information that is on the map that does not help with navigating is not only useless, but decreases the usefulness of the map by making it harder to read.  The information that we are required to have on the map for the assignemnt are as followed:

Ø  A north Arrow

Ø  A scale bar

Ø  Name of Projection

Ø  Name of coordinate system

Ø  Properly labeled grid in place

Ø  A background

Ø  List of data sources

Ø  Name of cartographer

I also wanted to add elevation to the map, because I saw blogs from a previous section of this class including it.  I think it is valuable information, and could be useful in navigation.  Another feature that I believe will be helpful to add is my pace count.

A pace count is the number of steps that it takes to travel a distance of 100 meters.  It is another objective of this lab, for us to determine our pace counts.  If you know what your pace count is, then when you are out in the field you can have a resonable estimate about the distance you have traveled based on your pace count, as long as you count your steps along the way.  Having this knowledge will be useful when we go to the Priory for our navigation activity.

The main point of this lab, is to get useful information that can we can use at the priory, and also apply critical thinking skills to determine what infomation is useful. We will have data given to us in the priory geodatabase that isn't reasonable to use in this particular map. It will be important to keep a focus on the purpose of the map when determing what information is pertinent to include.



Methods

The first step of the activity was to determine our pace step.  We did this together as a class.  We went to the parking sidewalk behind Phillips hall, where we used a laser range finder to measure out a distance of 100 feet.  We walked 100 feet, counting every time that our right foot went to the ground.  We did the same thing walking back, and then we averaged the two numbers to get our pace step.  The first 100 feet I got 67, and the next 100 feet I got 65.  My pace number was 66.  The numbers that I got were pretty close to one another, so I think I have a fairly accurate number for what my pace count is. If the numbers were further apart, I might be concerned that my pace was too variable during the measurement, and that this affects how accurate the pace count can be.

In the next part of the activity we worked on making navigation maps. We were provided with a geodatabase that contained data that could be used when making our maps.  The first step for me was to go through and determine which layers I thought were useful, and which ones I thought should not be used.  The main criteria for determining usablity, was whether I thought the information was peritinent to navigation, or if I thought it cluttered the map.

The first layer I looked at was a polygon entitled Navigationboundary.  There was no summary description in the item description, but presumably this is the area that we will be in during the navigation activity that these maps will be used in.  When looking at past blogs, people included some amount of space around the navigation boundary.  I decided this would be a good idea, in case we can get reference from features that are located outside of the navigation boundary, and that the space could be used for other information as well.

Figure 1.  Navigation boundary for Priory navigation activity

The next layer that I looked at was a Digital Raster Graphic that was a scanned image of  a US Geological Survey standard series topographic map. I decided not to use this for several reasons.  It was very cluttered, and the resolution was relatively poor.  Also, the item description did not include a date for when the map was made.  The map does label St. Bedes Academy which was established about 54 years ago, so I know it must have been made after 1961, but I do not have a more precise time frame than that and I do not know if the information is still relevant. 


Figure 2. DRG Scanned image of USGS topographic map, provided by the Natural Resources Conservation Service

I decided that I would use an Esri Imagery base map instead of the DRG scanned image USGS topographic map.  I chose this because I think that with less labels and lines, and being more current,  will be more useful for making navigation maps.

Figure 3. Esri imagery basemap shown with navigation boundary

The next layer I looked at was entitled priory_2ftcountours.  This shows contour lines for the areas, at every 2 foot difference in elevation.  Contour lines show a continuous line for points of equal elevation.  It can be a good way to show a three dimensional characteristic like elevation on a two dimensional surface. There was no summary or description given in the item description.  Although I think that there could be some usefulness in showing changes in elevation, I think that this would cause a problem with visibility, as it blocks out a large amount of the background imagery.

Figure 4. 2 ft contour lines at the priory, shown with Esri imagery base map

The next layer was entitled No_Shooting_Zone.  It consists of three polygons that indicate what I assume are places you are not allowed to shoot.  There was no summary or description given in the item description.  The no shooting zone was not mentioned as being part of the navigation activity, so I will not include it on my maps.

Figure 5.  Layer shows No Shooting Zone at the priory

The next layer was a raster entitled grdn45w092_13.  There was no description or summary in the item description, however I assume that it is a DEM or a digital elevation model.  I assume this because it looks similar to DEMs shown in past blog posts, and it shows values that would be expected when compared with the contour lines.  It is a good way to demonstrate changes in elevation.  I decided I would make it transparent, and increase the contrast, and add this layer to my final maps.

Figure 6. Digital Elevation Model of the Priory

The next layer that I looked at was contour lines for every 5 foot difference in elevation, clipped to within the navigation boundary.  These contour lines give useful information, but allow better visibility compared to the 2ft contour lines.  I decided that I would use these in my final maps

Figure 7.  Contour lines for every 5 feet inside the navigation boundary at the priory
 

The next consideration was to put in grids for each of the maps.  One of the maps would have a UTM (Universal Transeverse Mercator) grid, and the other would have a grid based on decimal degrees.  In the UTM coordinate system the world is divided into sixty zones, and each zone has a secant transverse mercator projection.  The properties that make the transverse mercator projection useful in navigation are as followed:

Shape and Area- Small shapes are represented accurately, and larger shapes are represented with minimum distortion.  Area is also kept with minimum distortion.

Distance and Direction- Local angles are kept accurate, and distortion for distance is minimized.

Figure 8.  Map showing 60 UTM zones

For the final maps, I decided that I would used background imagery from esri, The clipped 5ft contour lines found in the priory geodatabase, and also the DEM raster (with transparency and contrast both increased to make it more usable).  The final maps also contain grids in either UTM meters or in Decimal Degrees.  This grid should be useful in navigation.


Figure 9. Map with grid based on UTM

Figure 10.  Map with grid based on Decimal Degrees.

Discussion

When looking at other blog posts for this activity I noticed that their wasn't too much variation between the navigation maps.  Most people decided to use the 5ft contour lines, and some people also decided to include the DEM raster.  Also, most people decided to use the esri imagery for their background.  Most of the variation that I saw was differences in cartographic style.  The content of all of the maps is extremely similar.  I think that a reason that they look similar, is that this map needed to be simple.  The more that you may try to add, the less readable and the less useful the map becomes.

Most of the groups seem to be happy with the maps they produced, and when looking at their discussion during the field part of the activity, I saw the maps that were similar to mine were rated as useful.  The discussion that I saw focused on trying to figure out if the grid size they used was good enough, and if the elevation was clear to read.  As always, I think that any mistakes that I have made will be more apparent after the field activity, but for now I am confident that my maps can convey useful information for the navigation activity.

One concern that I had in making these maps, was the data that I used.  If the data in the geodatabse had not been given to me by my instructor, I would have been more cautious about using it, and I would have had to look for more information about where it actually came from.  Most of the features had little or no description about where they came from, what they were, or what time they were collected at.  Since it was given to me by my professor, I am confident that the data is reliable, but had this been a different situation, I would have spent more time trying to find metadata.

The biggest issue that I had in actually making the map, was remembering everything that I had learned about using ArcMap.  I felt I was working relatively slowly for the whole activity, which might have something to do with trying to remember how to perform all of the functions.  After the activity though, I think I remeber more of what I have already learned.


Conclusion

The objectives of the activity were completed through the making of a navigation map for the priory.  I learned several things from this activity. I learned what a pace count is and how to calculate it.  I also learned some basics for what features are useful to include in a navigation map.  In making the map, I think I learned a few lessons that are applicable to map making in general.  Since we will be using these maps in the future, it was important to me to make the map as clear as possible.  I think that if you keep the objective of whatever map you make in mind during the process of making it, you will have a better end result.  If you can imagine yourself using the map for the intended purpose, then you can better at understanding how to convey useful information.


Sources:
For Priory Information: WQOW
UTM zone map:  University of Deleware