Navigation Maps

Introduction
     The lab for this week consisted of creating two navigation maps for the Priory. The Priory is a 120 acres patch of land a couple of minutes south of the University of Wisconsin - Eau Claire. The maps created for this lab will be used to navigate these 120 acres of woods. The first map uses a Projected coordinate system and the other uses a geographical coordinate system.

Methods
     The Professor of the class obtained the data used to create this map from the United States Geological Survey or more commonly known as, USGS. The students of the class used this data too create two different maps. The first that was created was the one using the projected coordinate system. The projection used is the Universal Transverse Mercator (UTM) Zone 15. The UTM is a world wide projection system that breaks the world up into 60 zones. By doing this each zone experiences less distortion. This system uses meters for its linear unit. To create the map an areal image of the Priory was added. This was added to help identify features in the real world while conducting the navigation exercise. The second layer contains contour lines, which indicate the change in elevation of the land. These contours were originally given in 2 foot intervals but were switched to 2 meter intervals for two reasons. The first being that the linear units of the projection is meters and it is appropriate to have the contours units to match the projection units to improve the accuracy of the contours. The second reason is that the 2 ft. intervals were too detailed and it made reading the map difficult. The 2 meter intervals spread out the contour lines making the map easier to read. Another feature that was added to this map was an outline of the navigation area that is being used. This help to keep the students within the study area, hopefully. The final and most difficult part of this exercise was creating a grid that overlayed the entire map. The challenge of the grid was finding the right amount of detail to add while not cluttering the map too much. For the projection map a 50 meter interval was used to separate the grid cells.
     The second map that was created used the GCS North American 1983 geographic coordinate system(GCS). This coordinate system is designed to represent the North American and Pacific plates.  All of the same steps used in the first map were applied to this map. However the linear units of this GCS were decimal degrees. So the grid had to be converted to decimal degrees, with an interval of .001 decimal degrees separating the cells. Both maps contain a north arrow, scale bar, a water mark, which is simply the name of the creator of the map, the source of the data, and the coordinate systems used.

Discussion
      The projection map is posted below as figure 1. The projection map will be the easier and more useful of the two maps. Due to the projected system the features are more accurate and experience less distortion. Both maps use white contour lines because of the nature of the areal imagery. Basically the color white makes the lines easier to see than black.

(Figure 1: an image of the map using the UTM Projection for the Priory.)

     The second map is the one that uses the geographic coordinate system and is portrayed in figure 2. When comparing the two maps it is easy to see that the second is more stretched out and narrower than the project map. This distortion will make navigating slightly more difficult. 

(Figure 2: an Map of the Priory with a geographic coordinate system.)