Introduction:
In this lab we learned more about how to get the most out of a raster data set in ArcGIS Pro. We were given data from the "Wolf Creek Paving" mining site. We used this data in order to create maps displaying the area's elevation, hill shading, and slope. We also created several 3-dimensional images of the landscape that could be further manipulated in Arc Pro. Finally we used these images in order to create complete layout maps.
Here is a table of the metadata from the raster file we used. Image 1 shows a three-dimensional view of the "Wolf Creek Paving" site.
(Image 1)
Why are proper cartographic skills essential in working with UAS data?
Proper cartographic skills are necessary in order to work with UAS data because it makes the data collected by the UAS much more useful. For example, in this lab we worked with elevation data that was collected by a UAV. At the beginning of the lab it was very hard to make out what we were looking at. After adding things like hill-shading, aspects, and analyzing slopes it creates a much more clear image and maximizes the data that we were given to work with.
What are the fundamentals of turning either a drawing or an aerial image into a map?
In order to create a map from an aerial image you have to provide context for the data you are trying to express. A scale is necessary in order to provide reference for distance within the map. A compass is used in order to provide context for directional orientation. A title is used in order to give some notion as to what the purpose of the map is. The metadata from the UAS operation should also be displayed in order to explain what was used in order to collect the data. A legend is also necessary in order to understand the symbols and colors used in the map.
What can spatial patterns of data tell the reader about UAS data? Provide several examples.
Spatial patterns of data can express detailed information by relating coordinates to the area around it through the use of symbolic colors and patterns. A map key is often necessary in order to properly interpret this information. I will use the spatial patterns of data we used from the lab for examples.
The elevation map shown in image 2 below utilizes a color scale in order to express elevation. Image 3 shows the completed map layout with the scale. Image 4 is just an overhead view that also has some slope data.
(Image 2)
(Image 3)
(Image 4)
Image 5 uses a different color scale to express the slope. Slope is a measure of the degree of incline or "steepness" relative to the horizontal plane.
(Image 5)
Images 6-8 show the hill shading of the Wolf Creek Paving area. Hill shading is a method used in order to create relief maps. The technique uses a gray-scale to indicate relative slopes and changes in elevation, but not absolute height.
Image 6
(Image 7)
(Image 8)
What are the objectives of the lab?
One of the primary objectives of this lab is to learn how to turn aerial data into a complete map, and also learn the proper elements of a complete map. We also learn how to manifest several different spatial patterns of data and why they would be useful. We further practiced adjusting the symbology of different layers in order to create the best display. We also further explored the layout section of ArcGIS and used it to implement the essential parts of a map such as scales, north arrows, and map keys.
Methods:
One of the first things we were required to do was download and organize the data. This step is important because it allows you to recognize what type of data you are working with and you also have to properly store the file in order to access the database within ArcGIS. We also create a copy of the file's meta data. Important meta data to include would be the date flown, the UAS Platform, the sensor, the altitude flown, the ground control GPS, the ground control coordinates, the UAS coordinates, and the pilot. The coordinates are especially important because it allows you to know what type of coordinate system you are using.
Once we determined which coordinate system was used to collect the data we load a base map compatible with that coordinate system. We then proceeded to calculate pyramids and statistics for the data set. The process of calculating pyramids allows the program to scale down the data for display purposes. For example, if you were viewing a very large area at once with a lot of detailed data it allows this data to be displayed by scaling it down instead of attempting to load every single data point. This allows for the data to load faster when zooming in and out over the area. Calculating statistics like cell size, projection, and elevation range are important because it provides a reference point for any calculations and measurements.
In this lab we worked a lot with a DSM. It is important to know the difference between a DSM and a DEM. DSM stands for digital surface model. DEM stands for digital elevation model. Both DSM and DEM are created using photogrammetric methods. DSM contains elevation values of every surface including things like trees and buildings. A DEM, on the other hand, only shows the surface elevation values, with other values removed.
We proceeded to create several different layers of data displaying elevation, hill shading and slope. Slope is a measure of the degree of incline or "steepness" relative to the horizontal plane. Hill shading is a method used in order to create relief maps. The technique uses a gray-scale to indicate relative slopes and changes in elevation, but not absolute height. A color scale is also used to represent elevation in one of the layers. Images 2-8 above show the different spatial patterns of data we used in this lab.
Finally, we created layout maps of the different spatial patterns of data. These can be seen in images 3,5,7,9, and 10.
We proceeded to create several different layers of data displaying elevation, hill shading and slope. Slope is a measure of the degree of incline or "steepness" relative to the horizontal plane. Hill shading is a method used in order to create relief maps. The technique uses a gray-scale to indicate relative slopes and changes in elevation, but not absolute height. A color scale is also used to represent elevation in one of the layers. Images 2-8 above show the different spatial patterns of data we used in this lab.
Finally, we created layout maps of the different spatial patterns of data. These can be seen in images 3,5,7,9, and 10.
(Image 9)
Image 10
UAS data is especially useful to cartographers and GIS users because it allows one to collect large amounts of data quickly, and also allows sensors to be used in a much more useful way for collecting GIS information. The user of the data should always have access to the meta data and coordinate system information. I think that erosion information could be useful with this data because we discussed erosion as one of the issues on this site.
