Building a Map with UAS

This lab activity was structured around practicing cartographic skills with UAS data. The test site is Wolf Creek Paving in Wisconsin, and the map includes an orthomosaic, three dimensional model, and digit surface model. The map, being the next feature in this report, is followed by a series of scripted questions and respective answers. These questions are representative of the overall map making process.

Questions - Introductions

Q: What are proper cartographic skills essential in working with UAS data?
A: At the most fundamental level, a good spatial instinct is critical for working with UAS data, especially when working with different data sets. At larger scales, it is often more difficult to identify direction and orientation of data versus regional data due to a lack of features easier to identify on small scales. Second, an understanding of datum's and projections is critical. Both are critically important for accurate data, especially when working with multiple data types simultaneously.  Datums are more important to UAS versus other forms of remote sensing imagery because the height variable is more critical.

Q: What can spatial patterns of data tell the reader about UAS data? Provide several examples.
A: spatial patterns can inform the reader about important processes occurring on the surface. These can be patterns of land use, ecological changes, geomorphic changes, etc.  The spatial characteristics of a feature on the ground can tell about extent of processes impacting the area of interest. Things like crop health, soil erosion, hydrology gradients, animal nesting sites, and construction progress are all examples of what spatial patterns from UAS data can identify. The high spatial resolution of UAS allows for identification of patterns not visible with other remote sensing methods.

Q: What are the objectives of the lab?
A: To practice basic cartographic skills in the ArcGIS suite of software. To gain familiarity with high level mapping activities that may be advantageous in our career and our capstone projects.

Questions - Methods

Q: What key characteristics should go into folder and file naming conventions
A: A folder convention of increasingly specific folders is recommended. At the most fundamental level, a folder titled for a specific project will contain further folders of individual data types which will then contain more specific folders of operations. Each core file should be titled straight forward to contain the name of the operation and relevant metadata.

Q: Why is file management so key in working with UAS data?
A: Because UAS data can be remarkably extensive, with many different data types being part of the same project. This is especially true after data processing and the beginnings of analysis. Proper file management will enable successful navigation of data with little thought so that the correct data can be easily found and reliable chosen. Less mistakes will be made with proper file management.

Q:  What key forms of metadata should be associated with every UAS mission?
A: key metadata includes: Location, date, UAS platform, altitude flown, GPS system used, datum, projection, sensor information, band information if relevant, and perhaps pilot is some situations.

Q:  What basemap did you use? Why?
A: I used light grey canvas because it is relatively simple but still highlights important features such as large lakes or cities.

Q: What is the difference between a DSM and DEM?
A: A DSM, or digital surface model, tells height about the ground surface. Meaning ground level is considered a height of 0ft. Taller objects are measured in comparison to ground level. A DEM, or digital elevation model, is in reference to sea level. It ultimately tells topographical information and features total height including the ground elevation under an object.

Q:  What does hillshading do towards being able to visualize relief and topography?
A: Hillshading provides a better visualization of height by showing how sunlight would interact with the ground surface. Objects with height and general topographical changes will produce a different shading effect than objects next to it, making delineation of surfaces more clear.

 Q: How does the orthomosaic relate to what you see in the shaded relief of the DSM?
A: Features that are more clear in the orthomosaic due to color become more apparent in the DSM after shaded relief.

Q: What is the purpose of vertical exaggeration?
A: To make subtle features in the terrain more apparent in the overall model. Mathematically it does not change anything in the map, but it does make it more clear visually.

Q: What color ramp did you use? Why?
A: I used a red to green color ramp because there is a drastic contrast but a clear flow between the two colors. This makes high and low points very visibly different but elevation changes between them easily comparable.

Q: What are the advantages of using ArcScene to view UAS DSM data vs the overhead shaded relief in ArcMap? What are the disadvantages?
A: The advantages are that the model is completely manipulable in ArcScene. The software is essentially built to handle this form of information and interacting with a 3D model. The downside is it essentially is the model alone without much information of distance or metadata. It is a visualization tool, not much else.

Q: Is this export a map? Why or why not?
A: No, a map requires scale bars.

Questions - Conclusions

Q: Summarize what makes UAS data useful as a tool to the cartographer and GIS user?
A: It is an extremely high resolution data capture tool that can extract features not possible by satellite, but exponentially faster than by manned aircraft.

Q: What limitations does the data have? What should the user know about the data when working on it?
A: Despite very high spatial resolution, the data is only as accurate as the spatial positioning system used with the data. Standard GPS can be as inaccurate as three meters. At this level, at least for most purposes, it does not matter if the spatial resolution is much higher because it will not be as accurate as if a better positioning system was used.

Q: Speculate what other forms of data this data could be combined with to make it even more useful?
A: Ground measurements to either "truth" or subsidize the data. Being that this site appears to be a mine, information regarding estimated volume of Earth moved can be compared to drone derived volumetric measurements. Data regarding value of the materials being extracted can be used with volumetric analysis to discover the total economic value of the extracted materials in aggregate.