Charlie Krueger
GEOG 336
GPS Topographic Survey
Introduction:
This lab gave the class the task of gathering GPS points with a high precision GPS unit. The data points that were collected would then be used to create maps showing the change in something like elevation. The data was gathered with a GPS unit that gave the GPS position, the height above sea level and much more data. This lab was to created to show how the GPS locations could be gathered with different equipment and plus how the data collected can be used to show change by interpolating the data.
Study Area/Methods:
The study area of this lab was a section of land on the campus of the University of Wisconsin Eau Claire. This study area was chosen because Professor Hupy believed that it would show a decent amount of change from the data points gathered. The area was a small section of land on the campus between the buildings of Centennial Hall and Schofield Hall where the new construction had left a large hump of sorts.
When it came to collecting the data Professor Hupy demonstrated to the class about how to use the GPS unit that would take the point. This unit was one were a person would hold it and stick it into the ground so it holds the position and does not move around when collecting the data point. Once the point was it was stored inside of the GPS to then later be moved into an Excel spread sheet where the class could use the data. The data was then taken from the Excel document and downloaded into the program ArcMap. ArcMap would be the program that is used to create the maps with the interpolations. Once the data was downloaded and saved in a folder in ArcMap a shapefile would have to be created from the data so that it could be used when using the interpolation tools. The shapefile would be saved in a separate folder that only contained data for this lab. Once the shapefile was create the interpolations could be created using the program tools in ArcMap. These different types of interpolations would create maps from the data points using the Z value or height above sea level in meters in this lab as the main source. The different types of interpolations are defined in a previous blog named Visualizing and refining terrain survey Sandbox Part 2. This blog gives great definitions of the interpolations and when using certain ones comes in handy.
Results/Discussion:
Below are all the interpolations that were run in this lab and like in pervious lab there is obviously large differences between some of the interpolations. The interpolation that really captures the slope of the hillside would be Natural Neighbor because it shows the small step like lines increasing just like the hillside did when it was being measured and recorded. There was a small problem in this lab and it came from the time zones mix up when the GPS was still in time zone 16 when it should have been in 15. This was because it was used by Professor Hupy in Indiana prior to this lab and shows a great example of how technology can always get mixed up even though it was still giving results to the class.
Conclusion:
Overall this lab gave the class an opportunity to work with a very high grade GPS which some may use in their careers later in life. This lab was on the small scale but just shows how the data taken from the field can be used and analyzed by some many different programs such as ArcMap. The lab showed another good way to gather data and showed the class that even with such high grade equipment a small mistake like not changing time zones can throw off an entire dataset.
GPS Topographic Survey
Introduction:
This lab gave the class the task of gathering GPS points with a high precision GPS unit. The data points that were collected would then be used to create maps showing the change in something like elevation. The data was gathered with a GPS unit that gave the GPS position, the height above sea level and much more data. This lab was to created to show how the GPS locations could be gathered with different equipment and plus how the data collected can be used to show change by interpolating the data.
Study Area/Methods:
The study area of this lab was a section of land on the campus of the University of Wisconsin Eau Claire. This study area was chosen because Professor Hupy believed that it would show a decent amount of change from the data points gathered. The area was a small section of land on the campus between the buildings of Centennial Hall and Schofield Hall where the new construction had left a large hump of sorts.
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| The study area is near the circle growth on the map |
Results/Discussion:
Below are all the interpolations that were run in this lab and like in pervious lab there is obviously large differences between some of the interpolations. The interpolation that really captures the slope of the hillside would be Natural Neighbor because it shows the small step like lines increasing just like the hillside did when it was being measured and recorded. There was a small problem in this lab and it came from the time zones mix up when the GPS was still in time zone 16 when it should have been in 15. This was because it was used by Professor Hupy in Indiana prior to this lab and shows a great example of how technology can always get mixed up even though it was still giving results to the class.
Conclusion:
Overall this lab gave the class an opportunity to work with a very high grade GPS which some may use in their careers later in life. This lab was on the small scale but just shows how the data taken from the field can be used and analyzed by some many different programs such as ArcMap. The lab showed another good way to gather data and showed the class that even with such high grade equipment a small mistake like not changing time zones can throw off an entire dataset.
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