Lab Three: Creation of a Navigation Map

Figure 1. Finished hill shaded navigation map.  

All members of the class were required to create a navigation map of the area around the UWEC Priory. The Priory was a monastery at one point but it has been converted to a multiuse property that, amongst other things, houses students and offers a small slice of outdoor access to the college population. It is located south of the city of Eau Claire and encompasses an area of about half a square kilometer.

                It was decided that the best approach to the creation of a simple, uncluttered map, was to place a hill shade raster under a transparent image to give the effect of elevation without the mess of isometric contour lines. Figure two is the workflow model for the creation of the hill shade raster. The elevation data came from a Lidar dataset where six tracts were used to cover the area of interest. The first step was to collate the six .LAS files into a single multipoint feature class. I chose to only include the final return from the Lidar data as it typically signifies the ground level.  

Figure 2. Flow model showing the process used to create a hill shade raster from a Lidar dataset. 

The multipoint feature class was then re-projected to the same coordinate system (GCS North American 1983 HARN) and projection (NAD83 WISCRS Eau Claire County) as my dataframe. This projection can be defined as lambert conformal conic. It works well at portraying areas in the multitudes that stretch from East to West. I chose it because it was the most specific predefined projection available from Arcmap, meaning that any levels of distortion at this scale will be minimal.

After the multipoint feature was projected it was then converted to a raster file. This conversion included the option to set the cell size for each pixel and the values to be calculated. Each cell was set to have a spatial resolution of two meters with the mean of the elevation data set for each pixel. This gives a very good estimation for the elevation while producing a moderately smooth image.

From here it was a simple process to finish the operation by running the new raster image through a hill shade tool. The resulting image was placed under a true color satellite which was set to have 50 percent transparency. This creates a three dimensional effect on the image that makes it easy for a map reader to discern the location of hills, valleys and their respective slopes on the map.