Cartographic skills are essential to have when working with UAS data. Those skills are needed to both accurately interpret the data and be able to present that data in a way that a general audience could use and understand. Data collected by drones for UAS purposes is typically more robust than what a hobbyist drone user gathers with their platform(s). When applied commercially, the presentation of that data requires cartographic skills to meet the needs of the client.
* What are the fundamentals of turning either a drawing or an aerial image into a map?
To become a map, a drawing or image must have a north arrow, a scale bar, a locator Map, and data sources. Without that information present, what’s presented is incomplete, and the user is likely unable to delineate the data accurately. The image is thus likely to not serve it’s intended purpose.
* What can spatial patterns of data tell the reader about UAS data? Provide several examples.
Spatial patterns allow us to interpret, deduce and delineate information. They are found in naturally occurring areas, like a formation of ridges in a mountain range, as well as manmade patterns like the distance between city blocks. The texture, color, value, shade, shape and other objects and patterns all serve as visual ques that better help the author precisely portray what’s intended and the reader to better discern what’s presented. When devoted to human applications, the study of spatial patterns can be valuable in many ways. For example, city planner can use the data to combat “food deserts” in urban areas.
* What are the objectives of the lab?
The main objective of this lab is to teach a sense of understanding and appreciation for the level of expertise and amount of work/study needed to present UAS data in professional manner that one could take pride in. In that, it is also intended to help one understand what’s needed for a drawing or an image to become a map. Another objective of this lab is to obtain practice with ArcGIS Pro, ARC Map, and ARC Scene software, geographic information systems applications that allow the author to farm and calculate, present, and manipulate, geospatial data.
What is the difference between DSM and DEM?
DSM and DEM stand for Digital Surface Model and Digital Elevation Model, respectively. A DEM is a bare-Earth elevation model, unmodified from its original data source such as LIDAR (Light Detection and Ranging) and an autocorrelated photogrammetric surface. The DEM does not count for vegetation, buildings, and other non-ground objects. Alternatively, a DSM would include the tops of buildings, trees, powerlines, and any other objects. A DSM is often called a ‘canopy model’ as it only sees ground where there is nothing else over top of it.
What is the difference between a Georeferenced Mosaic and an Orthorectified Mosaic?
A mosaic is a collection of images that are stitched together to create a larger image that collectively display more area than the individual images. Georeferencing is the process of taking images that are in known coordinate systems, and providing the data necessary for software to understand which coordination system it is in and where in it. An image is georectified to be georeferenced, a process in which an image is put into a coordination system it was previously not in. Orthorectification means to adjust precisely, an image in a known coordination system, with distortions that correct topographic variation. An orthorectified image displays a uniform scale throughout. A DEM of which has its pixel values represent the ground elevation above sea level is required for true orthorectification.
* What types of patterns do you notice on the orthomosaic? Describe the regions you created by combining differences in topography and vegetation.
When delineating the map, one can see many features. The image above highlights some of those features. The yellow oval represents the soccer field and the track around it. The area highlighted in purple show objects that are elevated, including some vegetation in the form of trees, and a man-made structure. The blue line shows the mid-point of the variation in elevation depicted in the legend. The blue squares show cracks in the ground as well.
Evaluation:
1.
Prior to this activity, how would you rank
yourself in knowledge about the topic.
2-Very
Little Knowledge.
2.
Following this activity, how would you
rate the amount of knowledge you have on the topic.
3-I know
enough to repeat what I did.
3.
Did the hands-on approach to this activity
add to how much you were able to learn?
4-Agree
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