Field Outings

Operations

The field outings done in this class were meant to teach us the basic fundamentals of setting up an operation and using a Mavic 2 Pro to complete them. These missions were a good foundation for wrapping up and applying all of the things that we have been taught over the course of the semester. We went over every aspect of UAS operations: mission planning, pre-flight checklists, flying, and data processing. This post will go into detail about every aspect of each mission but first, some important mission planning steps were taken and need to be explained.

Checklists

One of the most important things to do before every flying an aircraft is to ensure that the proper pre-flight checklists have been followed. This helps to ensure that every aspect of the aircraft, the equipment, and the flight area are all checked and deemed okay. For the Mavic 2 Pro, we were tasked with practicing going through the checklist with our flight crew before even stepping foot outside of the lab. When we got out into the field the checklist was almost memorized and we were able to ensure we did not miss any steps. The checklist below outlines all of the steps that should be taken when in the lab, during pre-flight setup, during flight, and the take down process of all the equipment. This is to be followed for every operation.

(Figure.1 Mavic 2 Pro Checklist)

Mission Planning

The next big step in UAS operations is planning out the mission. In the case of the field outings, we used Measure Ground Control to create grid based flights over specific areas of Purdue Wildlife Area. These were created prior to setting up the aircraft and was checked by the professor to ensure that it was adequate for the desired mission. While we have flown at PWA before this semester and we are all fairly familiar with the location, it is helpful to use a GIS software in order to look at the operation site beforehand. Identifying any possible environmental obstacles such as power lines, buildings, or dense areas of trees can help to ensure that when it is time to fly the mission the flight crew is well aware of any inhibitors. 

 

Ground Control Points

 

For every mission that we flew we wanted to ensure that we had accurate data. Ground control points, once placed, sit in a single spot and collect its exact location. Those coordinates are then used during data processing to ensure that we have an accurate analysis. These are highly accurate and help to produce good quality results. For all of our field outings, we placed a varying number of ground control points called AeroPoints. Once placed, the user presses the button to start the recording process and must leave it there for roughly 45 minutes. For our case, we placed them in the desired location and then started setting up for the mission. By the time all of the flights were completed, enough time had passed to be able to pick them up. GCPs are picked up in the opposite order that they were placed. For example, they are placed in order 1-5 so they should be picked up 5-1.

 

Data Processing

 

This aspect of the missions is immensely important. After flying the mission we were left with a large amount of images. These images can be used but they can be better utilized if they are processed. With this in mind, we took all of the images and plugged them into a program called Pix4D. Pix4D is a photogrammetry software used for drone mapping. This program allows us to essentially stitch all of the images together to make one complete image. These complete images are known as orthomosaics and can be used to create maps and display information. Pix4D also creates what is known as a digital surface model. DSMs are similar to orthomosaics except they show the elevation of the images stitched together. Examples of these are shown below.

 

Week 12

 

For this mission, our task was to fly with a grid on Measure Ground Control over the southern most fields and construction site at Purdue Wildlife Area. The mission was overall fairly short, lasting roughly 5 minutes. Using MGC, the aircraft autonomously followed the flight plan we created, taking pictures at regular intervals. Once the aircraft finished the flight path it returned home to where I took over manual control and landed the aircraft. The aircraft was then packed up and the data was processed. Below are the maps created using the data collected.

(Figure.2 Week 12 Orthomosaic PWA)

(Figure.3 Week 12 DSM PWA)

Week 13

Week 13 was in the same location as week 12 and the mission was conducted much the same way. However, this time we flew the same grid with a crosshatch flight path and the camera at a 60-degree angle. By doing this, we were able to plug the images into Pix4D and actually get a 3D model of the area that we flew. While the 3D model shown below is not the best quality, with more images these models can get immensely detailed. After flying the crosshatch mission, we also flew a small grid north of this area over the burn fields. This was a simple grid flight like week 12 and the maps created from the data are below.

Flight #1 - 60-degree camera angle with crosshatch

(Figure.4 Pix4D Model - Construction site)

(Figure.5 Pix4D Model - Salamander Tanks)

(Figure.6 Pix4D Model - Vehicle)

(Figure.7 Week 13 Flight #1 Crosshatch Ortho)

(Figure.8 Week 13 Flight #1 Crosshatch DSM)

 

Flight #2 - 90-degree camera angle with standard grid

(Figure.9 Week 13 Flight #2 Standard Grid Ortho)

(Figure.10 Week 13 Flight #2 Standard Grid DSM)

Week 14

For week 14 we flew the same exact mission as week 12. This was a standard grid flight over the southernmost field at PWA. The ground control points and the flight paths were very similar. However, for this mission we used an app called ArcCollector. This app allowed us to calculate the location of our GCPs via GPS by walking near them and capturing their location and a picture. Our maps reflected the discrepencies in accuracy between the ArcCollector points and the GCPs. Furthermore, as a final deliverable we used all 3 week's data to compare the burn fields. Something to note is that my flight crew had an issue with the images from week 12 saving correctly. Therefore, I had to redo the first flight. For the comparison map, the dates will reflect the correct comparison over time.

(Figure.11 Week 14 PWA Ortho)

(Figure.12 PWA Burn Plot Comparison)

Reflection

From the multiple field outings I learned a lot regarding how to plan a mission correctly and how to successfully complete the operation. Having a hands-on with the flights and then processing the data was very helpful. From this semester, I have learned the importance of mission planning, checklists, and processing data. Most importantly, because of my issues during week 12, I have learned that ensuring all of the equipment is set up correctly is crucial to success. In the future, I will ensure that I am more careful and diligent with missions. AT 319 as taught me the amount possibilities UAS and GIS have when working together.