Field Activity #5: Development of Field Navigation Map

Introduction

The purpose of this activity was to create a navigation map that will be used for the following field activity. That activity will involve manually plotting waypoints and their associated coordinates that will be provided for us by the professor. To create this map several data sets were provided for us. From the given selection we were to create a map that would provide us with the ability to know the terrain we are traversing; as well as being able to plot the points within reasonable accuracy. This map also needed to include some type of coordinate system that would be appropriate for conducting a survey at a large geographic scale at the local level.

Methods

To begin, the first thing we did a class was go outside and establish our pace count. A pace count provides you with ability to know how many steps you take within a given distance. We did this because this will be our method for measuring the distance we travel during our survey for the following week. To do this we used a distance finder and established a distance of 100 meters. Then, the class walked to the distance 2 to 4 times to get an average consistency. My pace count was about 68-70 steps within the 100 meter distance.

Next, we went inside and started on to create our maps. Data set provided to us by the professor included color and black and white aerial images, a digital elevation model (DEM), a 2-foot contour line map, a 5-foot contour line map, a clipping boundary, and a point boundary. It was our choice for what which data sets we chose to utilize. We were given the guidance of being told that some of the best maps for this type of project are simple ones. Having a map that is “too busy” can impede on the navigation. We were also told we could make a two-sided map for reference purposes.

With that, I chose to use both the 2 and 5-foot contour data sets (images 1 and 2), the point boundary data set (image 3), and a 50x50 meter grid (image 4)for the main navigation map that will be used to plot the points. The 2-foot contour file was generated during a UWEC survey and the 5-foot contour file was generated from a 1/3 arc second DEM that was obtained from the United States Geological Survey (USGS) seamless server. I chose both the contours because together they create a very precise, yet simple, vision of the landscape terrain. The point boundary data was created for us by our professor. I used to the point boundary data set for reference of the specific area the points will be located within. Finally, the 50x50 meter grid is a feature that is created in Arc Map.  I chose a 50x50 meter dimension because I felt it was detailed enough for the terrain, and because I didn’t want the grid to be “too busy” and distracting. This size also works well because our pace count was based on 100 meters so I would be able to cut my pace count in half, to about 34-36 steps per 50 meters. This would also provide better accuracy.

Image 1: 2-foot contour map used for representation of land terrain

Image 2: 5-foot contour map used for representation of land terrain

 

 

Image 3: Boundary of area where points will be contained

 

 

Image 4: 50x50 meter grid used to for distance measurements

 

 I also chose to create a second map for the backside of my main map for reference purposes. This would include a color aerial image of survey area (image 5), the 5-foot contour, and the point boundary data sets; along with the 50x50 meter grid. Again, the aerial image was produced by the USGS, like the 5-foot contour file. I chose the colored image because it would be easier to depict the landscape, as opposed to a black and white image. I chose the 5-foot contour because it is detailed, easy to reference with it also being on the main map, and not “too busy”. I chose the point boundary, again to know the specific location in which the points would be located. Finally, I chose the 50x50 meter grid, again for reference to the main map.

Image 5: Aerial image of survey area

 

 

If I were to have had to obtain these files myself I would have started by Google searching downloadable GIS data, and looking through the options provided to me. Past experience in downloading GIS data has taught me that USGS in one of the best sites to obtain data, especially aerial imagery.

The actual process in creating the map was a little more difficult than any of us were expecting. We thought it was going to be as simple as bringing the data sets in, setting the layers data frame to UTM 15 (which is the projection we were instructed to use because it allows the ability to measure distance), and adding the grid. However, the problem we ran into was that the 2-foot contour map was a CAD file that was originated by a UWEC survey. In order to use this CAD file in ArcMap it had to be georeferenced to a raster. This process was done for the class by another geospatial technician who works in the Geography department at school. He informed us that he georeferenced the CAD file to the aerial image (which is a raster), which had a different projection from the UTM 15. The aerial image was originally projected in NAD83 Wisconsin Transverse Mercator. Therefore, when the data frame was projected to UTM 15 the 2-foot contour map didn’t line up correctly.

So, we collaborated as a class and figured out how to use the data sets we needed; while having all the proper projections. The steps we took to do this include the following:

1)      We started a new project in ArcMap and set the page layout to a landscape view, with 11x17 dimesions (image 6).

 Image 6: Page set-up of a landscape view and 11x17 dimensions

 

 

2)      Next, we brought the aerial image in first (image 7). This set the data frame to NAD83 Wisconsin Transverse Mercator. By having the data frame set to this projection all other data sets brought in will be set to this same projection by a feature in ArcMap, known as project on the fly.

 Image 7: Aerial image of survey area brought into ArcMap to set correct data frame projection

 

 

3)      Then, we brought in the 2-foot contour CAD file (image 8). This lined up properly to the aerial image since the data frame was the same projection it was in when the CAD file was georeferenced to the aerial image.

 Image 8: 2-foot contour file brought in next to properly overlay the aerial image after georeferencing  was established

 

 

4)      Next, the 5-foot contour data set was brought in (image 9). The original projection on this file was GCS North American 1983. But, because of project on the fly the data set automatically projected to that of the data frame, NAD83 Wisconsin Transverse Mercator, and lined up properly. We, also labeled the 5-foot contour lines for reference in the field.

 Image 9: 5-foot contour file brought into ArcMap
 

 

5)      Then, the point boundary data set was brought in (image 10). The original projection on this file was NAD 1983 UTM Zone 15N. But, again because of project on the fly the data set automatically projected to that of the data frame, and lined up properly.

 Image 10: Point boundary data set brought in last

 

 

6)      Finally, it was time to create the 50x50 meter grid. This was done by first putting the map into layout view. Then, opening up the data frame properties, and clicking on the “Grid” tab (image 11). Then, by clicking on “New Grid” we were able to select the parameters for creating the right grid for our map. First, we selected to create a “Measured Grid”. The next screen allowed us to select the projection for the grid and set it the dimensions we wanted, 50x50 meters (image 12). After completing the set-up for the grid we were able to create labels (image 13) for the dimensions, which will allow for accurate reference in the field.

Image 11: First step in creating a grid in ArcMap

 

 Image 12: Setting grid’s projection and defining it’s dimensions

 

 

Image 13: Creating labels for the grid

 

 

7)      Finally, all the components we needed for our maps were in Arc Map and projected properly (image 14).

Image 14: All components in ArcMap to create our navigation maps, with proper projections

 

8)      To create my final maps I simply used to the map we just created, with the steps above, to make my main map. I turned off the aerial image, kept the map in layout view, and added appropriate text to it (image 15).

Image 15: Final main navigational map completed

 

9)      To create my final reference map, I started over from scratch with a blank map template. I then followed the steps outlined above to make sure all projections were correct. This time I didn’t have to add the 2-foot contour, because I wasn’t using it on this map. Again, I added appropriate text to the map (image 16).

Image 16: Final reference map completed

 

Discussion

It was a good thing we worked together on this as a team. I’m sure the issue with not having the correct projections would’ve messed a lot of people up in the navigation part of the survey for the following week. Since our survey will be based off of distance and direction it’s important to have a map where whose components match our survey techniques. The UTM projection is a good one for this project because it minimizes distortion of properties, such as shape, distance, direction, and area.

Conclusion

Overall, I think everyone benefited from team work. It will be exciting to see how well our map designs benefit, or hinder us in the field.