Lab 13: GPS and Map Navigation

Introduction:
  Previously in lab 3, the class was broken into several groups of 2 people where each group  created 4 navigation maps and submitted the best to be printed by Dr. Hupy so that each group could put their map making and reading skills to the test during this week's navigation lab.  The goal of this lab was for each group to use the maps they created along with a GPS unit  to locate 5 marked trees assigned to each group with its coordinates at the Priory dorms located off campus at the UWEC Children's Nature Academy. (see Figure 1 below)

Figure 1 A bird's eye view of the navigation area

Methods:

  The class met at the Priory location where Dr. Hupy passed out the printed maps the class submitted earlier and gave the groups each a Etrex GPS unit and a list of

Figure 2
 marked tree coordinates

 coordinates where 5 trees per group were marked to find. (see Figure 2) When passing out the printed maps, it was realized that my partner and I's map missed the printing process! So it was decided that the groups condense to 4 people per group. Many of the groups compared their maps noticed differences in coordinate systems used by each other and those set to find by Dr. Hupy.

Figure 3 Etrex GPS

The group's map also had the grids latitude numbering cut off so a few other groups maps was consulted to sketch in the numbers. Then the group used the new sketched in grid to estimate the locations of the 5 points. Although after realizing the estimated points were a bit off from their true location the group decided to use the location coordinates of the Etrex GPS for extra assurance. (see Figure 3) The group then set out to the east to find the first marker. To know which direction to head the coordinates of the GPS were used to tell which direction was closer to the mark by moving in a straight line as the number got closer to the marked point, or if the number went farther in the opposite direction the group knew to turn back the other direction.

Figure 4 Marker 2

 Deer paths in the woods were very helpful while navigating especially on slopes. After circling around the 1st marker through sticker bushes it was found wrapped around a fallen tree on a

Figure 5 Group members with 1st marked tree

slope near a large patch of ferns. (see Figure 5) While searching for the next point a mowed path was found which was able to be followed a ways before the GPS lead us back into the woods. This time on the other side of the path where the land became flat and was covered by lined mature pine trees  which was quite different from the sloped mixed vegetation side.  The group excitedly found the next marker near a busy road but realized it was the 3rd marker rather than the second. (see Figure 6) 

Figure 6 the next marker found

The group headed back to the path and up towards the slope to find the 2nd mark (see Figure 4) on the  steep side with many fallen trees. From there the group headed north to find the 4th point which was near a small pond at the end of the path at the edge of the tree line. The last marker was finally found another slope this time with quite a few fallen trees.  Once all the marker had been found the groups returned to the parking where the navigation began to return the GPS's back to Dr. Hupy who informed us that he would share the data from them in the class folder so that a map could be made of each group's journey. The map created in Lab 3 for the navigation was used as the base for the track log and the recorded points from the GPS which was added to the map in ArcMap after the files were saved to their own specific Lab 13 folder. Then the symbology was changed to create the map below.







Results:

The above map shows the path of Group 20 during the navigation activity. The purple points follow the tracks the group took throughout their journey. The blue x's indicate the marked trees the group was assigned to find.

Conclusion:
  Most if not all the groups ran into minute problems mainly dealing with with the map coordinate systems and the differences between them and the coordinate system used but luckily most were able to use the GPS's and their geographic sense to navigate the Priory grounds to find all 5 of the marked trees.

Lab 12: UAS 3D Imagery

    

Introduction:

    Lab for this week was in preparation for a future UAS or Unmanned Aerial Systems lab. This lab focused on the image data the UAS take. Dr. hupy gave the class two file folders of images taken by a previous class, one of a track field and another of a baseball field both within the city of Eau Claire, Wisconsin.  The objective this week was to transform these images into 3D composite views in an attractive map form. 

              

                Figure 1  Selecting the aerial photos for PixMapper              Figure 2 Selecting 3D Models in the New Project window

Methods:

      To begin the project Pix4DMapper Pro was opened to a new project the entire file folder of images of the track field was added first while Dr. Hupy explained some of the steps. (see figures 1 & 2)  After making sure the project will save to the desired folder, continuing through the setup windows  and choosing to create a 3D model, a map view with points appears. (see Figure 3)

Figure 3 first view of data in mapview on Pix4D Mapper Pro

 This is a view showing where the images are "tied down" to the earth. In the bottom left of the screen is a Processing window, here is where each picture is matched up through points, vertices and geotags which are associated with each image and looking at each pixel's intensity values to make bands and putting them all together ​ to create a point cloud.

Figure 4 Processing window

 A point cloud is the 3D visualization of an object on an attached coordinate system. Each of the processes were run and automatically saved to the designated folder for this lab. Once the processing was finished a new image appeared on the screen along with a quality report. (see Figures 5, 6, 7 & 8) 

                                                                               Figures 5, 6 & 7 from the quality report:                

Figure 8 Image after processing showing camera points

              

            Figure 9 Measuring 3D area volume

Dr. Hupy also wanted each student to measure the length of a linear feature, calculate the area of a surface,  the volume of a 3D object and create a video showing different views of the project. (see video below) This was completed under the RayCloud tab and new polyline, new surface and new volume.(see Figure 9)

  

Figure 10 Measuring a New Polyline

Once selected, manual pinpoints were placed on distinctive areas of the image to calculate each. (see figure 10) When all the measurements were complete the project was opened in ArcScene by adding the tif in the orthographic folder. To make the image 3D the base height was set to custom float to the DSM tif in its folder. (see Figure 11)

Figure 11 Adding float to base level in ArcMap

 From there the 3D image was saved as a layer file and brought into ArcMap where it was transformed into a map. These steps were completed the same for the baseball field image folder as well.

Results:

Above is the 3D image created from the photographs taken by the unmanned aerial system. Each photo becomes like a pixel as the matched areas accurately tie the imagery to the globe and compute the height of the objects pictured.

Conclusions:
         Through various programs a fairly accurate 3D representation can be created from a UAS image files in a fairly simple manner.