Mission Planning

Introduction

          The purpose of this lab is to get some experience with the mission planning software called C3P. Along with how the mission planning software works, other essentials of planning a successful mission will also be discussed. Using a mission planning software helps increase the accuracy of a drone flight and does not require the pilot of the drone to do the entire flight by hand. This mission planning software allows the user to manipulate every variable that affects the flight. The altitude and the spacing of the grid which is the resolution can both be set, as well as a specific flight area. The lower the flight is conducted at, the higher the resolution, additionally flight time will increase as well. If the flight is done at a high altitude, the resolution will decrease as will flight time. In this lab, two areas will have test mission flight areas done. Area one will be Bramer Test Field, the second will be a pond that is located in Dunn County to the East of the City of Menominee. Throughout the lab, the limitations of C3P will be discussed, as well as an overall review and final thoughts of the software. 

Mission Planning 

          Prior to departing for the mission there is a number of different variables to account for, that if neglected could end the flight before it starts. The first step is to know the study area, it is important to know what obstacles could be in the area, as well as the general layout of the surface. It is good to do this in order to know if a cell signal will be available if the tablet being used depends on a cell signal. On a different note, it is important to know if there will be crowds in the area watching the flight, if so the operator must be very careful as it is illegal to fly over a crowd. The terrain is essential because it will dictate how the flight is done, the drones need room to turn around and if there is a hill, trees, telephone wire, cell towers or other obstructions that will dictate altitude the planner will want to know about that before showing up for a job. Additionally, weather checks prior to getting to the flight area are important, windy and or rain could delay or even stop the flight. On the mechanical side of things, always be sure that batteries are charged and that all of the equipment is in top functional shape. 

         Upon arriving at the field there are still a number of things to check off before beginning the flight. In order to select a safe home, takeoff and rally point the weather must be checked again. The current weather as well as weather conditions for the future should be noted and factored in. The wind speed, wind direction, temperature, and dew point should be recorded. Additionally, a detailed look into the vegetation of the area will be beneficial to unsure that there are no obstacles that did not show up when doing the initial planning in the office. The drone must always take off into the wind and also land into the wind, going with the wind could cause the user to lose control and to damage or lose the drone all together. A correct elevation must be taken, as the drone will be flying at a specific altitude to ensure data integrity. One final issue to take note of is the possibility of electromagnetic interference such as power stations, power lines, or underground metal or cables. Be sure to make it clear to the team what units are being used, metric is preferred as it is best for simple conversions. The final step before flight is to make sure the cell signal is established and not going in and out and the mission should be reevaluated to make sure every variable is correct. Figure 1 below shows the mission settings and how all of the variables can be changed to adjust for the flight area.

Figure 1

C3P

Get to Know the Software

          The C3P software is started by selecting the points for home, takeoff (T), rally (R) and land (L). These locations will be different for each study area, and depend mainly on the wind direction and strength. Different maps can be used, the default from C3P, ArcMap or even google maps, it is almost always best to use a map that displays imagery to get an idea of the terrain. Next, a flight can be made using the draw tool, the draw by area is the most commonly used way to set up a flight area. The mission settings can be set up however the remote operator sees fit. The mission settings include altitude, speed, overlap, sidelap, GSD (pixel resolution) and the type of camera used and overshoot. The altitude used is determined by the desired resolution, as well as making sure the drone will clear any obstacles in the flight path, so it is important to calculate a correct absolute altitude. As a rule of thumb the speed should be 16-18 m/s. There should be overlap of 80% of more, as well as 70% side overlap to ensure the flight has good accuracy. The overshoot can also be changed and it is important to make sure that the drone will not hit anything when overshooting to correct itself. Certain land features such as hills or mountains can dictate the direction of the flight because the drone may be able to overlap one way, but not the other. 

Figure 2

  
        Figure 2 above shows the flight with the altitude at 100 meters, and figure 3 below shows the flight at 200 meters. Figure one shows that there will be issues with the path of the drone as shown by the bright orange on the right side. Additionally, the figure 3 shows that there will be no issues. If there are red circles as shown in figure 2, be sure to increase the altitude or to slightly vary the flight path. 

Figure 3

           When working with different altitudes it is important to make note of the differences in altitude types within the software. Absolute altitude is the height the aircraft is above the terrain it is flying over. In contrast, true or relative altitude is the actual height above mean sea level.

Figure 4

         Figure 4 shows a flight path using the draw tool with street points, that allow the drone user to fly along a linear feature such as the road depicted. The 3D view shown is from ArcGIS and this allows for the pilot to see the types of terrain and vegetation around the flight area. Be sure when running a flight similar to this that the drone being used has the battery life to make a successful flight. 

Figure 5

         Figure 5 above shows the area to the west of the city of Menominee Wisconsin which is a pond in the middle of an 80 by 80 acre field section. The pond is roughly 60 acres and holds good duck numbers throughout the year. If the land owner wanted to get an elevation map made as well as a more detail high resolution map this would be an option. The planning software did not account for telephone poles that are on the land, though they may be very new because they are not shown on the aerial imagery from ESRI.

Figure 6

          Figure 6 shows the area of the flight. The silos in the upper left had to be avoided as well as to the upper right hand corner. It was tough to get the correct positions for things because the circles were bound to have some overlap. The area is surrounding by roads, making it a little tight, though if this were done in real life there is plenty of field to deal with home and take off and landing. The flight needed to be run with the overshoot being north and south because there is more free space to the north and south of the pond. 
Review

         Without a question this mission planning software is much more convenient than having to calculate and write down all the variables by hand. The fact that the software shows the user where the drone will hit if the altitude is low enough is really nice. This software can be a little bit sophisticated when first starting so just as in ArcMap, the use of help was very beneficial. There is so many nice features in this program. Having the flight time accounted for from the battery life is key to time management. Additionally, the software can update for the weather conditions, this takes even more stress off the operator. With that being said, this is still a man made software that could be inaccurate. Pilots of these flights should always double and triple check every variable of the flight and I would also urge that they stay attentive at all times in case the altitude was not correct or the wind changes. Also when working on my own location for a flight the mission software did not account for the silos that were located in the upper left, also I had the square larger and flying under 25 meters. With my previous knowledge I knew that there would be issues with telephone poles, but the software did not register that.