Introduction
For this job we will be using several different geospatial analytical tools to help produce for you client with your requested deliverables. Some of the key analytical tools that we will be using to help deliver the data will include maps such as that containing classified objects, detailed insets map of GCP points used as well as Hill shade maps from the 2 different flights with a side by side of the orthomosaic produced. Through these maps you will be able to easily identify key information regarding the burned areas of Purdue Wildlife and where growth of plants can and cant be seen.
Methods
Purdue Wildlife Area (PWA)is a hub for research and development of the Purdue Forestry and Natural Resources department at the university. Vast research is conducted every year in this area in an attempt to further individuals' understanding of the growth of plants such as those seen in the surrounding area of PWA. Given the task at hand of examining the rate of growth of the controlled burned area of PWA, it was necessary to conduct two separate flights to collect data. The purpose of flying to missions is so that we can gather a before and after type of data set. With that in mind, the missions were flown with a 7-day separation period to allow for adequate change in the landscape to be seen when processing the data. The usage of GCPs otherwise known as Ground Control Points was also used during the data collection period. Ground Control Points help us with the data processing to ensure that our locations throughout all of our maps are as precise as possible. Furthermore, they are a good way of establishing visual reference points to help identify the area of study. Once all of our data collection was complete we used 3d modeling software specifically PIX-4d, which is widely used throughout the 3d modeling community. Making slight adjustments to adjust for GCP location was also done using this software. Finally using ESRI ARC-GIS pro we were able to take the processed data from PIX-4d and run geospatial analytical processes such as object-based classification. After these geospatial analytical processes, cartographically correct maps were able to be generated as you will see in this report. The maps demonstrate our findings in regards to the growth of plants after conducting controlled burns.
Discussion
Figures 1 and 2 : Figures 1 and 2 showcase the quality reports generated from PIX4D. All the green checkmarks mean all the processing items went smoothly while yellow indicates the processing wasn’t perfect but was okay.
Figure 3: These are the original Ground Control Point locations being shown in figure 7. The blue dots as illustrated by the map are the GCP locations while the red square is the mission area where all activities related to the collection of data was conducted. This also serves as a locator map.
Figure 4: This map shows a comparison between my GCP’s that I observed using a handheld GPS such as my phone and compares it the actual GCP placement.
Figure 5: In this image you can clearly see visually the zoomed in images of the GCP point. The GCP points are represented in the images by the white square box with the cross on the inside. This type of map helps give you a bit of locational reference so you know where everything is.
Figures 6 through 7: Figures 10 and 11 are the same type of maps just representing the data from both flights 1 and 2. The DSM for flight 2 did come out better than the DSM for flight 1. One key detail I want to point out is how the elevation values changed as you can see by the color scale on each map which corresponds to an elevation value. This illustrates how as a result of the burn of the area the elevation did in fact decrease as seen in flight 2.
Figure 8: The side-by-side comparison of both the missions showing both the DSM as well as the orthomosaic help allows you to see how the landmass changed given the course of 1 week.
Figures 9 through 10: These maps illustrate object-based classification from the two different flights conducted. As you can see on the maps there is a noticeable change between the burned and unburned areas illustrated.
Figure 11: Comparison of the burned and unburned area of PWA between the flights. As you can see there is a change in the area of each classification as time changes.
Figures and Maps
Figure 1: Quality Report of Initial Processing
Figure 2: Point cloud and mesh quality report
Figure 3: PWA GCP
Figure 4: GCP location for Josh Grobart)
Figure 5: Detailed Ground Control Point Locations of PWA
Figure 6: Side by side of DSM and Orthomosaic flight 1)
Figure 7: Side by side DSM and Orthomosaic Flight 2
Figure 8: Comparison of the two missions flown
Figure 9: Object Based Classification Flight 1
Figure 10: Object Based Classification Flight 2
Figure 11: Comparison of Burned and Unburned Areas
Comentarios