Mapping with a Balloon Part 2

Introduction
In the second week of the balloon mapping exercise our class sought to capture aerial imagery for most of lower and upper campus of the University of Wisconsin-Eau Claire (UWEC). After doing two practice launches last week with the helium balloon, we had the opportunity to make any necessary modifications to improve the model and ensure the quality of aerial photographs over campus. Taking what the class has learned from the trial launches and knowing the behavior of the rig with respect to the wind, made this final launch attempt a success. The balloon ascended to the class goal of 400 feet above the surface thanks in part due to the light winds on that day. At this height, the digital camera mounted on the new and improved rig took excellent pictures at better angles. Taking advantage of the favorable weather conditions, the class took the balloon to cover a signficant part of lower campus including the area across the university footbridge by the Haas and HSS buildings. The balloon also visited upper campus where the flight ended at Towers field by the residence halls. Photographs uploaded from the digital camera numbered close to 5,000 giving the class plenty of images to georeference and mosaic. Using the same groups from previous exercises, the instructor gave each a specific area of campus to mosaic, which will be later combined with the other groups to display aerial imagery of the entire study area. Figure 1 shows the area assigned to my group (3) that needed to be mosaicked in ArcMap. This report will cover a breakdown of the methods employed during the creation and launch of the final balloon launch, the resulting aerial images of group 3's area, and the obstacles encountered during the activity.

Figure 1: Portion of UWEC to be Mosaicked by Group 3

Methodology
Since the class had a week to prepare and learn from the two "experiment" launches, the methods for this week's exercise followed many of the same steps as the previous activity. Balloon mapping requires a significant amount of preparation and experimentation before the official launch of the device that will collect the data for the final erial image of school grounds. Aside from conducting similar steps from the first two balloon launches conducted for readying purposes (measuring out 400 feet of rope, blowing balloon up with helium, and determining clear flight paths to take around campus), this report will detail the process of modifying an effective rig design, launching the balloon, searching for the images in the study area, georeferencing the images to a referenced image, and mosaicking them to make up a high resolution aerial photograph of campus.

After learning from last week’s trial launches, the class is more familiar with using the balloon mapping equipment and ready to make any necessary improvements to the rig and any other tactics that will be employed in the final launch of the device. Stacy, Brandon, and I were given the task of creating and designing the rig for the the two trial launches as well as the on for this week. Since the rig from last week’s launch experienced too much movement due to strong wind gusts and snapped off, the next step is to modify the rig in this week’s launch and minimize motion as much as possible from the wind. Instead of going with the Styrofoam container that held the camera in the trial launches, the new rig will be much simpler and consist of construction paper cut out in the shape of a triangle attached to a plastic rod (Stacy’s idea), firm string, the digital camera, zip ties that attaches the camera to the rod, electrical tape around the camera for more stability, and a rubber band wrapped around the camera button to take multiple continuous pictures throughout the duration of the launch. Stacy had tested out how the rig would behave under strong winds using a regular box fan at home while holding it by a string. This new design proved to work as the rig experienced minimal movement even with the fan on high. Although the rig is made simple, the lightweight nature of this model and the wing at the tail increases the chance of capturing quality images at better angles than the heavier Styrofoam rig from last week. Figure 2 shows the design of the new and improved rig for the final launch.

Figure 2: The New and Improved Rig Design

The Launch:

Once the rig and 400 feet of rope was ready to be attached to the inflated helium balloon, the class was ready to launch the model on campus. Although a flight path around the new Davies center and campus mall had been predetermined to capture the extent of the renovation that UWEC has undergone since it began 2010, me and zach took the balloon to other parts around school grounds inlcuding the rest of lower campus, across the Chippewa River near Haas and HSS buildings, and a portion of upper campus displayed in Figure 3. We were able to cover a significant part of campus thanks to the clearing of trees from construction. After exploring the area across the footbridge (Haas and HSS), the balloon had to be lowered on the south side of Haas (building adjoining the footbridge) because there were too many branches to safely pass through while the balloon remained in the air. Once we crossed the river onto lower campus, the balloon was let go for a second time and taken to upper campus to map the residence halls and the student cafeteria. The class took the balloon as far as Towers field on upper campus where it's flight ended.

Figure 3: Parts of UWEC Campus Visited by the Balloon Mapping Model

   

The next method is to upload and search through the images from the camera. Although we found that the camera battery had died after lowering the balloon the second time, it took almost 5,000 photographs of our entire flight path during its launch. My group was responsible for finding images that covered the area displayed in Figure 1, which covers mostly lower campus but also parts of upper campus including the student cafeteria and the wooded area known as Putnam Park. These images can be found from the beginning and end of our first launch. When the balloon was first launched it covered the areas of lower campus by the library and nursing building, which are including in group 3's study area. Even though the Haas and HSS buildings are not included in the study area, the images taken near there are also used because they captured much of the Chippewa River, which is in it. The start of the second launch on lower campus was another area where I looked for photographs because the flight path moved west along the river towards upper campus. In order to get the best quality of a campus aerial image, there needed to be at least 60 percent overlap between the photographs.

Once the camera images that cover group 3's study area are selected and sorted through, the next step is to georeference them to a referenced image in ArcMap. When images are georeferenced, they are aligned to a map coordinate system because they usually do not contain information about the area that they capture from a camera. ArcMap allows the user to bring in jpegs as a raster, which can be manipulated using the georeferencing tool bar. The images will be georeferenced to another raster data set that has existing spatial data and a desired map coordinate system. This reference image of the UW Eau Claire vicinity is provided to us by the instructor. A minimum of 9 control points, which are ground points with known x,y coordinates that link locations on the image with locations in the spatially referenced image, are to be added to each image linking it to the reference photo.

The fifth method is to mosaic the newly georeferenced images to a new raster shown in Figure 4. This will combine the images into one whole image that covers the desired section assigned to group 3. In ArcMap, the Mosaic to New Raster tool is used to output a new raster image with all of the other images connected together. It is important to note that in order to run this mosaic tool, the input raster images need to have the same number of bands and bit depth. Since all of the images from the camera have the same characteristics running the tool should not be an issue.

Figure 4: Mosaicked Image of Group 3 Study Area of UWEC

The last method is to use Extract By Mask tool in ArcMap, which will only display the area that is assigned to group 3. This raster processing tool extracts the cells of a raster that match to the areas defined by a mask and is found under Spatial Analyst in ArcToolbox. Figure 5 shows the extracted image of group 3's portion of UW Eau Claire's campus.

Figure 5: Group 3's Extracted Portion of UWEC



Discussion

One obstacle that we confronted during the balloon mapping exercise was the tree branches getting in the way of the flight path. Although the class planned a clear flight path a week prior, the instructor and the students driving the device (me and Zac) decided to go to other parts of campus to capture images. Once the area around campus mall and the new Davies center was covered, new flight paths were added spontaneously, which include parts of upper campus and the Hass building across the Chippewa River.  

 

The next issue occurred when using the Mosaic to New Raster tool in ArcMap to combine the images. The output image would appear black or not show up at all. To fix the output when it appears black, one can go into properties of the feature class and go into the Symbology tab. Make sure the RGB Composite is highlighted in the upper left of the Layer Properties screen and where it says Type in the Stretch section click the down arrow and select none. This should change the coloring of the image and it should appear as normal once applied. 

Another obstacle was mosaicking the images together so that the features in the final mosaicked output would line up perfectly with one another. Figure 6 shows sections of Putnam road that do not match up with each other making it appear as a disconnected feature rather than a continuous one. The distortions are caused by three different georeferenced images that were not stacked on each other in the correct order. When running the Mosaic to New Raster tool, it is important to take into consideration the order of layer stacking. The best quality image should be overlaid on top while all of the other layers should be stacked appropriately to make the overall view of the image appear as connected as possible. Although the order of layer stacking is essential to mosaicking images together, the Root Mean Square Error (RMSE) is another factor that needs attention when georeferencing. This statistic provides a good measure of accuracy for how close the images' features match up and is given for each control point when added to the image and onto the referenced image. An ideal georeferenced image for this activity should have a RMSE less than 2.0.  

 

Figure 6: Disconnected Segments of Putnam Road Depicted by the Arrows

   

 

Finally, group 3's study area was not well covered by the balloon in some parts. I had difficulty finding quality images that covered parts of the Chippewa River and Putnam Park on upper campus. This prevented me from mosaicking an image for the entire study area.

 

The new design of the rig in the second week helped tremendously capture quality images. It can be windy at higher altitudes of over 400 feet especially near the Chippewa River, but with the rig being light weight and having a wind breaking wing attached to it created for more stability. Different designs of rigs should be researched before launching to the sky.

 

Conclusion

The balloon mapping exercise helped improve my ability to collect aerial imagery by using simple tools and how to conduct post processing of the images in ArcMap. After preparing and testing out the various rig designs, the final launch proved to be successful at capturing high resolution images. I have taken a lot out of this experience by learning how to obtain aerial imagery over a particular parcel of land without using high tech equipment.  

      

Balloon Mapping of UWEC Campus

Introduction

            There are many methods to obtain aerial imagery of an area whether it is via satellite or aircraft. The development of this new technology in the 20^th century has provided the world with reliable high resolution aerial imagery of the earth. Although these are the principal tools being used today to collect images, they are expensive to build and run. This week’s exercise entails for the class to develop a model that will map part of the University of Wisconsin-Eau Claire campus using a balloon filled with helium. Each of the six groups is responsible for georeferencing and mosaicking a particular section of campus. This report will cover what the class did last week to prepare for this week’s exercise, a breakdown of the methods employed during the creation and launch of the balloon, the resulting aerial image from group 3, and the obstacles faced during the activity.

Methodology

            Balloon mapping requires a significant amount of preparation and experimentation before the official launch of the device that will collect the data for the final aerial image of school grounds. The study is split up into two activities that include the preparation and testing of the balloon mapping tools in week one and the actual launch in week two, which will collect the data for producing the complete campus image. This project is laid out in the following methods: prepare and experiment with the balloon mapping tools to conduct two trial launches in week one, modify rig designs, measure out 400 feet of rope, blow balloon up with a proper amount of helium, and determine a clear flight path.    

            In last week’s exercise, the class had the opportunity to prepare and experiment for this week’s official launch of the helium balloon over the UWEC campus. There were two practice launches in this activity, one for taking aerial images of campus and the other for recording video images. This allowed for the creation of various rig designs, which attach to the balloon and contain the camera inside. Since wind is a big factor at 400 feet in the air, the rig had to be designed to withstand strong gusts and ensure the camera could take quality images of the ground below. Stacy, Brandon, and I had the responsibility of creating and designing the rig for the two trial launches as well as the final one. Figure 1 displays the rig design used in the first experiment launch of the balloon. Another objective of week one’s exercise was to get familiar with the flight paths of the balloon over certain areas of the campus. The flight path is important because the best quality images are taken directly below camera and the class wanted to capture in detail recent aerial imagery showing the transformation of UWEC particularly in the campus mall and the new Davies center. One obstacle with the flight path is staying clear of branches that get in the way of the individual on the ground driving the device and the rope attached to the balloon 400 feet above.

Figure 1: Rig Design in the First Balloon Launch



 

           After learning from last week’s trial launches, the class is more familiar with using the balloon mapping equipment and ready to make any necessary improvements to the rig and any other tactics that will be employed in the final launch of the device. Since the rig from last week’s launch experienced too much movement and snapped off, the next step is to modify the rig in this week’s launch and minimize motion as much as possible from the wind. Instead of going with the Styrofoam container that held the camera in last week’s launch, the new rig will be much simpler and consist of construction paper cut out in the shape of a triangle attached to a plastic rod (Stacy’s idea), firm string, the digital camera, zip ties that attaches the camera to the rod, electrical tape around the camera for more stability, and a rubber band wrapped around the camera button to take multiple continuous pictures throughout the duration of the launch. Figure 2 shows the design of the new and improved rig for the final launch.

Figure 2: New and Improved Rig for the Final Balloon Launch

 

          The third method is to measure out 400 feet of rope that will be the height of the balloon above campus when it is launched. In order to keep track of how much rope it let out once the balloon is ready to be launched in the field, the 400 feet of rope is marked at every 50 foot segment. The class was able to do this in one of the hallways long enough in the Phillips science building on campus shown in Figure 3.

Figure 3: Measuring 400 Feet of Rope

 

          The fourth method is blowing up the balloon with enough helium to ensure that it will reach the goal of 400 feet above campus. A helium tank and a balloon specialized in reaching higher altitudes are used in this step shown in Figure 4. Once the balloon inflates to a diameter of about 5 feet, it is ready for launching.

Figure 4: Inflating the Balloon with Helium

 

         The fifth method is determining a clear flight path to drive the balloon around campus. After experimenting on the areas that were possible to go with the balloon last week, the class followed a similar path around the campus mall and the new Davies center. There were also new flight paths taken around campus, which was permitted by a day with light winds and a significant portion of the school grounds being cleared from thick trees. The other flight paths traced around the Phillips science building and then across to the footbridge by the Haas building. Aerial imagery of upper campus was also collected by the device.

            Once the launch has been completed, images from the camera can be uploaded to the computer and used for the sixth method, which is georeferencing the ones that are in the section assigned to my group (group 3) in ArcMap. When images are georeferenced, they are aligned to a map coordinate system because they usually do not contain information about the area that they capture from a camera. ArcMap allows the user to bring in jpegs as a raster, which can be manipulated using the georeferencing tool bar. The images will be georeferenced to another raster data set that has existing spatial data and a desired map coordinate system. This reference image of the UW Eau Claire vicinity is provided to us by the instructor. A minimum of 9 control points, which are ground points with known x,y coordinates that link locations on the image with locations in the spatially referenced image, are to be added to each image linking it to the reference photo.

            The last method is to mosaic the newly georeferenced images to a new raster shown in Figure 5. This will combine the images into one whole image that covers the desired section assigned to group 3. In ArcMap, the Mosaic to New Raster tool is used to output a new raster image with all of the other images connected together. It is important to note that in order to run this mosaic tool, the input raster images need to have the same number of bands and bit depth. Since all of the images from the camera have the same characteristics aforementioned to run the tool without error, there is no issue.

Figure 5: Mosaicked Image for Group 3

 

Discussion

            Although balloon mapping provides an easy and inexpensive way to collect aerial imagery, there were a few obstacles encountered during the activities. The major issue was the design of the rig and how it behaved in the wind. Since the study depends on the collection of images, it is imperative that the camera lens faces in a downward direction and not swing at angles. The rigs of the first two trial launches were made out of Styrofoam and shaped as a cube, which proved to be too much mass that was easily affected by even delicate wind gusts. It also did not help the fact that the winds were at sustained speeds of 15 miles per hour that first day the balloon rigs were launched. As a result, the photos captured from the camera did not turn out as clear or taken at direct angles as images from the second week when the winds were light and a new rig was launched. If the two trial launches were not conducted a week prior, the images for this week’s balloon launch would have been more distorted and lesser quality.

            Another obstacle during the balloon mapping exercise was the tree branches getting in the way of the flight path. Although the class planned a clear flight path a week prior, the instructor and the students driving the device (me and Zac) decided to go to other parts of campus to capture images. Once the area around campus mall and the new Davies center was covered, new flight paths were added spontaneously including parts of upper campus and the Hass building across the Chippewa River.

            Finally, the last problem occurred when using the Mosaic to New Raster tool in ArcMap when combining the images. The output image would appear black or not show up at all. To fix the output when it appears black, one can go into properties of the feature class and go into the Symbology tab. Make sure the RGB Composite is highlighted in the upper left of the Layer Properties screen and where it says Type in the Stretch section click the down arrow and select none. This should change the coloring of the image and it should appear as normal once applied.

            The new design of the rig in the second week helped tremendously capture quality images. It can be windy at higher altitudes of over 400 feet especially near the Chippewa River, but with the rig being light weight and having a wind breaking wing attached to it created for more stability. Different designs of rigs should be researched before launching to the sky.

 

Conclusion

            The balloon mapping exercise helped improve my ability to collect aerial imagery by using simple tools and how to conduct post processing of the images in ArcMap. After preparing and testing out the various rig designs, the final launch proved to be successful at capturing high resolution images. I have taken a lot out of this experience by learning how to obtain aerial imagery over a particular parcel of land without using high tech equipment.             

Implementing Navigation Techniques at the Priory

Introduction

            Navigating in an area can be done in several different ways. After spending the last couple weeks at the Priory, the Geospatial Field Methods class has gained valuable navigation skills by employing a variety of techniques. Although most navigation methods today are incorporated with technology and are more accessible to the general public, they may not always be reliable; therefore it is important to have an understanding of both the technology part and using a basic topographic map. The first activity called for the class to navigate in groups of three to a series of waypoints at the site by using a compass and two topographic maps. The second activity gave the class an opportunity to use a GPS unit and find a different set of waypoints in the study area while the third activity used both the map and the GPS unit to find all points on the property. This report will include a description of the study area, a breakdown of the methods for each technique that was employed (map vs. GPS unit), the resulting track log maps, and a comparison of the two methods.

Study Area

            The Priory is located just south of the Eau Claire, Wisconsin city limits on Priory Road. The former monastery chapel used to be named Benedictine Hall until the UW-Eau Claire foundation purchased the property to turn it into a new children’s center, which is now called the Children’s Nature Academy. The 100 plus acre property adjoins Interstate 94 to the north and is surrounded by a low density residential neighborhood in rural Eau Claire. Although a large building that serves as the daycare sits on the land parcel (Figure 1), most of the property is wooded and hilly making it difficult to navigate to a particular point (Figure 2). The Priory also features a couple of ponds that lie next to the freeway, which also provide another obstacle for the group to navigate around and remain on course. With all of the different types of terrain that are found in the Priory property, navigation techniques must be conducted carefully and accurately in order to find the set of waypoints.  

Figure 1: The Priory, Eau Claire, Wisconsin

 

Figure 2: Wooded Terrain at the Priory



 

Methodology

Navigating around an area requires a significant amount of preparation and knowledge of using the various instruments for each technique. The study was split up into three separate activities, which gave the class an opportunity to work in small groups and navigate to five specific locations in the Priory first by using a map/compass and then with a GPS unit for the following week’s exercise. The third activity at the Priory involved using all three instruments to locate all points in the property. This project will detail the methods that were applied in each exercise of navigating the Priory.

Field Navigation Map and Compass

            Before one can navigate in an unfamiliar area, preparation and development of two field navigation maps must be created. These maps were created in ArcMap using the feature classes in the Priory Geodatabase, which was provided by the instructor. The first step is to bring in the aerial image of Western Eau Claire in the GIS and clip it to the Priory study area using the navigation boundary feature class. Having an aerial image as a basemap under the contour lines will help with the navigation exercise for the following week when the class visits the study area. The next step is to bring in the 5 meter contour lines that will go over the aerial image. Since ArcMap does on the fly projection, it is easy to forget about what the projection and coordinate systems are for each feature class. It is important to note that each feature class that was given to the class has a different projection. The 5 meter contour line feature class is projected in GCS North American 1983; the aerial image of Eau Claire has a projection of NAD 83 Wisconsin Transverse Mercator; the navigation boundary feature class has a projection of NAD 1983 UTM zone 15 North. Although all of these feature classes have a different projection, they all line up with each other in ArcMap because of on the fly projection.

When the 2 meter contour line map was created, the projection and coordinate system became an issue because none of the feature classes would overlay or match up with that particular feature class in ArcMap. The data for this feature class is based on a UWEC survey, which was converted from AutoCAD files. Since the data source for the feature class displays an undefined coordinate system, the 2 meter contour feature class has no spatial reference and cannot be lined up with the pre-existing data that have a defined projection in ArcMap. This poses a problem for navigating because the contour lines need to overlay the study area in the same projection to ensure that the results are more accurate. To fix the problem, our class started a new screen in ArcMap and brought in the clipped aerial image into the design view and then the 2 meter contour line feature class right after it. After doing this, our feature classes were able to match up with on the fly projection. If this was not done, our lines could have been significantly off on our navigation maps and give us inaccurate results of finding the exact point locations. The root of the problem is to make sure that all of the files are projected the same.

The next method is to set the grid in layout view in ArcMap for every 20 meters. The 20 meter interval will be used on the navigation map because the 10 meter interval made it too hard to read the contour lines on the map because it is so cluttered with information and lines. Going any higher than 20 meters will also make it hard to pinpoint the location of the points that need to be found in the study area.

Another important step is to set the grid to NAD 1983 UTM Zone 15 North. Using UTM coordinates for navigation makes it possible to measure distance especially for the small study area. Once this is complete, the field navigation maps can be created using the 5 meter contour line intervals and the other using the 2 meter intervals in ArcMap.

           Figure 3 shows the map with the 5 meter contour line intervals. An aerial basemap is placed underneath the contour lines so that the group can find their location on the map relative to the features at the actual site. The 5 meter contour interval allows for a basemap because it is not as detailed as a topographic map with 2 meter contour intervals. Figure 4 shows the map with the 2 meter contour line intervals, which does not include a basemap for the sake of reducing the clutter of detail on it and keeping its function for navigation.

Figure 3: Priory Navigation Map with 5 Meter Contour Line Intervals



Figure 4: Priory Navigation Map with 2 Meter Contour Line Intervals



The materials needed in the navigation activity include the following: magnetic compass, 5 meter contour lined map, 2 meter contour lined map, punch card, and the list of waypoints for the assigned course. Since the points provided by the instructor are in UTM, it is essential to have the grid coordinates in UTM on the navigation map. One of the maps that the group picked did not have these coordinates making it useless on the day of the activity. Fortunately all of the other groups had UTM coordinates on their grid and my group was given a usable map for the navigation exercise. The class was also given a refresher on how to use a magnetic compass for navigating in the field.

            Once the materials are gathered for the navigation exercise, the waypoints can be plotted on the map according to their given UTM coordinates (Figure 5). The instructor created 3 courses around the Priory property for each group to go out and punch in at 5 specific locations throughout study area. My group was assigned course 2, which included trekking over different levels of terrain between each point. Since the map that the group used had a 20 meter grid, each member checked to make sure that the points were accurate enough before moving on to the next step.

Figure 5: Plotting Course 2 Points on the Navigation Map

 

            The next method is to find compass bearings between each set of waypoints on the navigation map. Straight lines were drawn between the points so that the compass can be aligned in the exact direction of the next point on the list. Using the magnetic compass, one can take the direction of travel arrow and align it on the line between a set of points. For example, we took the compass and placed it on the map aligning it with the line between the starting point and the first point on course 2. This method was done for each plotted point on the map. We then had to move the compass house with degree dial until the “N”, which indicates north, points to the top of the navigation map. The top of the map for this study is assumed to be true north and is closely lined up with the tilted vertical gridlines. Once the “N” is pointed to top of the map, the group can look at the index line where it says “read bearing here” and record it so that it can be used to find the next point. These bearings will help us in the field once we get to a specific spot by showing us the direction that we need to face to reach the next point.

            Another method is to measure the distance between each point on the map using the scale bar and a piece of paper. We discovered that one of our group members has a consistent pace count of 65 for every 100 meters. Knowing the distances between each point will give us an idea how far we will need to go before looking for the landmark point on our list. The deep snow and rough terrain, which includes steep hills and thick forests, may throw off the consistent pace count making it necessary to add 15-20 steps for every 100 meters.

            The second last method is designating the roles for each group member while navigating in the field. We had one person (me) manipulate and hold the compass according to the bearings and face in the direction of the point on the map. Since there were many steep hills and fallen trees in the way of each point, a second person (Hannah) was responsible for moving to the landmark in the direction dictated by the person holding the compass (Figure 6). This allowed for each trek between the set of points to be done in segments and ensure better accuracy in the direction of travel. Once our group member reached the landmark in the direction of the compass holder, the other person (Kory) did the pace count to that spot. Kory would add to his pace count until the group reached marker for our next point (Figure 7).

Figure 6: Group Member moving to designated landmark in the distance (dictated by compass holder)

 

Figure 7: One of the Markers in Course 2

 

 

            The last method is to go out with the group to navigate and collect punches at each point on course 2. This required good communication between the members to ensure that we were heading in the right direction and finding ways to overcome obstacles along the way. Both the 2 meter contour and 5 meter contour line maps were utilized in this activity because each included features that were helpful in navigating to the destination points. One map had an aerial basemap under the lines, which made it easy to tell where we were on the property of the Priory and whether or not we were getting close to a plotted point.

Navigating with a GPS Unit

The ability to navigate easily in an unfamiliar area or region is made possible through new technology such as a GPS. This instrument allows people to pinpoint their location and navigate to the location that is desired without needing timely preparation that is associated with a map and a compass. This activity called for the class to divide in the same groups and navigate to 5 different points in the Priory property using a GPS unit.          

The first method is to check out a Garmin etrex legend H GPS unit from the geography department at the University of Wisconsin-Eau Claire. This GPS instrument provides accurate coordinates of where the person holding the device is located. Once the GPS is obtained, it is important to learn how the track log function works on it before going out into the field. To get to this screen, turn on the device by pressing the on button located on the right side and second one down. Next press the top right side button twice to get to the track log screen where it gives the option to turn the track log on. Any stored track logs in the device from previous users should be erased so it shows only the data for the navigation activity. The track log should also be turned on once the group arrives to the starting point of their assigned course in the study area.

            The second method is navigating to the starting point of the course that the group was assigned. Since my group did course 2 last week, we had to navigate through course 3 this week denoted with a “b” after each number in Figure 8. Finding the starting point was not an easy task as our group was provided with a GPS and a list of coordinates in UTM that we had to navigate to. Fortunately, the GPS is also equipped with a compass screen, which helped us decide the direction of travel our group needed to move in order to reach the desired coordinates on the list. The group noticed that as one moved to the east, the X UTM coordinates increased and the same occurred with the Y UTM coordinates as one moved to the north. Ultimately, we decided to focus on getting to the Y UTM coordinate first and then move east or west to the X UTM coordinate depending on our location from that point. Once the group reached the last point on the list (6b), we turned off the track logs on the GPS.

            The third method is to upload the track log points as UTM NAD 83 in the DNR Garmin program. These points can then be imported to a Geodatabase in ArcMap as a point feature class and projected to NAD 83 UTM zone 15N if necessary. ArcMap is used to show the path of the track logs on a map of each individual group in the class.

            The last method is to create three maps showing all of the class track logs from the exercise. Figure 8 shows my individual track log (track log 27), which follows course 3 going from 1b-6b sequentially. Figure 9 includes the track logs of my group on the same course. Lastly, Figure 10 displays the track logs for the entire class and covers all three courses in the study area.

Figure 8: Track Log 27 Course 3

Figure 9: Group 3's Track Logs Course 3

Figure 10: All Geography 491 Field Methods Class Track Logs

 

Implementing both Navigation Techniques in the Priory

            The third week’s activity allowed the class to navigate using both techniques from the previous two weeks in the same groups. Since each group member was equipped with a map, compass, a GPS unit and a list of waypoints, this activity’s objective was to locate and track all fifteen points in the Priory in a strategic way because it was a race against the other groups. With this challenge accepted, my group decided to rely more on the navigation map from the first activity and have the GPS unit ready in case our location was far from the destination set of coordinates. Exploring the property for the third time helped with this navigation exercise because the class became familiar with the land and the general location of the waypoints. Nevertheless, we utilized both the map and the GPS unit repeatedly throughout the course to find the specific points. Each group member had to keep a track log throughout the navigating exercise and record a waypoint once arriving to a marker indicating a destination point on the map. Figure 11 displays my track log for this exercise with the starting point at 1a. Points 1 and 1b did not have to be recorded because of being located in the restricted zones. Although my group only found thirteen of the fifteen points on property, it would have taken longer if we were not equipped with a map and a GPS unit. Figure 12 shows my group’s track logs, which show a similar path to mine. Figure 13 displays all of the track logs from class and clearly shows the different paths that other groups took to reach the points.

Figure 11: Track Log 27- All Courses

Figure 12: Group 3's Track Logs- All Courses



Figure 13: All Geography 491 Field Methods Class Track Logs

 

 

            After starting out at point 1a in Figure 12, my group headed for point 6b and round the property ending with point 2a. The methods of finding each point are the same as the ones in the first two exercises, however there was more of a reliance on the map and GPS unit than on the compass. My group also utilized land features such as the edge of a forest to locate the markers. Between points 4b and 5a, we used the border of the evergreen forest to go in the right direction. The coordinates on the navigation map and aerial imagery helped speed up the process of moving through the Priory course.

Discussion

            When comparing the track logs from Figures 8 and 11, it is evident that the track logs from the final activity are going in a straighter and more direct direction towards the points. One reason for this is that the Garmin GPS unit only showed the UTM X and Y coordinates and cardinal directions, whereas the map displayed all of that along with aerial imagery and other terrain features such as elevation. It is important to know that when navigating with a GPS unit in UTM coordinates that the X coordinates increase moving to the east and the Y coordinates increase going in a north direction. Having a map helped my group’s navigation abilities in this exercise and also sped up the process of completing most of the course. As aforementioned, the map’s aerial imagery gave us a better idea of what my group needed to look for in the terrain and what general direction they had to go to reach the next point.

            The first navigation activity with a topographic map and a compass reduced the dependence on technology to do the navigation for us. Although this navigation method is not as easy as it looks, we found that it is fairly accurate and led us to find the points on the map without too many issues. The two meter contour line map was an advantage for us in this exercise because it showed us the type of terrain in our direction of travel. Not only could we see that there was a steep hill in front of us, but the map also confirmed a steep change in elevation ahead. The aerial basemap was also beneficial to finding the location of these points by helping us see if we had to go through a dense forest of evergreen trees or around a large pond. The other advantage of our preparation before going out to field was plotting the distances we needed to travel in 100 meter intervals. This gave us an idea of how far it was to the next point while taking into consideration the pace count of the walker.

            Although there are many advantages to our navigation maps in this exercise, one disadvantage is the difficulty of being able to read the map with the 2 meter contour lines because it also included the aerial map. The next navigation map should have a more transparent the aerial map so that it is easier for even a non-geographer to read and navigate with. Another obstacle we faced while locating the points was trying to maneuver around the ponds near the freeway. Since this land feature was in the direct path of one of our points, we had to go around it and estimate Kory’s pace count once we got to the other side. It was difficult to use the pace count to measure our distance because we established what our pace count was in a parking lot that was cleared free of snow. The last disadvantage was our attempt to move in a straight line through the deep snow and thick forest. Even though it is winter and the trees are not filled with much vegetation, there are many fallen down logs and small trees that got in our way. We were able to overcome this by designating a visible landmark in the distance that connected with our path and have that as a meeting point before moving on.

            Overall, the last activity with both the map and the GPS unit went the fastest. As long as the maps are detailed and contain essential information such as the coordinates in UTM, aerial imagery, contour lines, and the course point location, it can serve to be a great resource alongside a GPS. After navigating with both techniques through the Priory, it is evident that a GPS and a navigation map can navigate successfully separately, but are more effective when used together.

Conclusion

            The field navigation exercises helped improve my navigation abilities in the field by learning about three different methods: navigation with a traditional map and a compass, GPS unit navigation, and navigation with a GPS unit accompanied with a traditional map. Although the last technique proved to be the fastest and most efficient way to navigate around a plot of land, the GPS unit is also quick at finding a set of coordinates. The slowest method out of the three was the first one where my group used a map and a compass to navigate. Even though it is a time consuming way to locate a particular point, it does not rely on technology and can be helpful if we did not have that luxury at hand. It is important to have an understanding of the many navigation methods that are available especially when there is travelling involved in conducting field work.