Lab 11: Topographic Survey with Total Station

Dr. Hupy and group partner with equipment

Introduction:

    Lab this week was in comparison to the distance azimuthal lab two weeks prior which was about simple survey methods using lower grade technology.  Here the class broken into groups of two, used a total station, the ___ to collect various points with attached elevation data  throughout the University of Wisconsin - Eau Claire's  campus mall on lower campus in order to create a  digital elevation model or DEM of the study area (see Figure 1).

Figure 1 Location of survey on UWEC lower campus

Methodology:

Figure 3 GPS

Figure 2 Total Station

Figure 4 Stadia rod facing total station

    ​The class gathered around Dr. Hupy and the  total station accompanied by the geography department (technology person) Martin Goettl, there Dr. Hupy  introduced the _  (see Figures 2 & 3)and the lab before instructing the class to break down into their groups of two so each group may once again take turns joining him to record several points. The total station must remain in a single location throughout the survey at a known static point or occupied point. This selected destination point is recorded when (60) "mini" points are collected and averaged for high accuracy. Before beginning the survey the total station needs to have some priorities set like how high the station and the stadia rod's prism  is from the the ground and the orientation of the station itself.   To do this one can measure out the heights and input them into the GPS then a couple

Figure 5 Prism on stadia rod

locations are selected as backsights. for this lab 2 backsights were chosen and were marked with an orange flag. The orientation angle is calculated through the coordinates of the station and the backsights by measuring angle and distance of the backsights to the station using the stadia rod. Once ready to record a point one group member would go out in the area being surveyed with the stadia rod and places it in locations every few feet from each other. when a point's location is decided the stadia rod must be leveled (see Figure 4). Then the prism atop the stadia rod needs to be positioned facing the total station while the group member at the station focuses the magnifies lense over the center of the prism on the stadia rod. (see Figure 5)

Figure 6 Using display XY data tool

When centered the group member at the station can you the GPS to record the point. Once each group had its turn and all the points were recorded Dr. Hupy sent the data through notepad to the class. From here the notepad could be brought in directly to ArcMap and was easily edited in excel after using the table to excel command found by using the search box on the right of the screen. Figure shows the edited excel file which was brought in and replaced the previous table. The table was then converted into XY data (see Figure 6) to visualize the point features (see Figure 7). From there the kriging tool used 3D Interpolation

Figure 7 After using Kriging tool

used to create a continuous surface. This tool is found under the Raster Interpolation of the 3D Analyst folder in the Toolbox. To be able to view the terrain in 3D the feature is saved as a layer file and brought into ArcScene where its properties are edited by checking the Float box and raise its base level from 0. The point layer file is also added and then both were brought back into ArcMap to create the final map below in the results section.





Here is an equation and model from ESRI's website to better understand how kriging works:

                          

 

Results:
    Below is the final map created by this survey. The darkest areas are deepest in elevation while the light areas show the higher.  THe orange flags represents the backsights and the blue pin point marks the location of the total station during the survey. This collected data and interpolation model turned out to be very accurate to the real terrain. 

Conclusion:

     This lab showed itself to be in quite a contrast to the previous lower grade technology lab. This survey turned out very accurately and was simple efficient and effective.