April 8, 2019

2 April 2019 Martell Forest Summary and Field Notes


            Disclaimer: This post is a general overview of the flights of Martell Forest flown with the DJI M600 on April 2nd and not meant to be an in depth analysis of the day’s flights. 

Introduction:
            On Tuesday, April 2th, our AT319 class went to Martell Forest to fly the Zenmuse X5 RGB sensor. The UAV used was the DJI M600 and the Zenmuse X5 was mounted on a gimbal. Figure 1 below shows an image of the M600 sitting on the launch pad with the Zenmuse affixed underneath it. 
Figure 1: M600 with Zenmuse X5

            The location of the flight was Martell Forest and the mission was to fly two flights with the M600 in a cross grid pattern one with the camera at nadir and the other with the camera at 60° below the horizon.

            The goal of the mission was to both collect data as well as to get our AT319 class experienced working as a team to setup and run all aspects of a UAS operation. To this end, at the location, the class split into two groups, one to setup the M600 and the other to set out the GCPs. Since I helped set up the UAV in the previous mission, I went with the group setting out the Propellor AeroPoints GCPs. 

AeroPoint GCP Placement:
            When placing the AeroPoint GCPs there are several important factors that must be taken into account for successful deployment. These factors are listed below:

  • Clear view of sky 
    • It is essential that the GCPs have a clear view of the sky so that they may receive GPS signals from satellites.
      • Tree cover may affect these weak signals and may cause inaccuracies to occur.
  • GCPs within sensor coverage areas
    • GCPs must be placed in an area that will be visible to the UAV in multiple photos so that they may be properly used when processing.
  • Even distribution
    • GCPs must be evenly distributed throughout the mission area so that the data is not pulled/skewed by many GCPs in one area and no GCPs in another when processing. 
  • Terrain changes
    • If the terrain varies significantly across the mission area, distribute some of the GCPs in high and low areas.
  • Line-of-Sight
    • The AeroPoint GCPs communicate with one another while they are in place so it is important that they are somewhat visible to each other.
  • GCPs on
    • Turn each GCP on only after they are placed to avoid erroneous readings and bad data.
  • Photograph and note each GCP’s location
    • Take pictures of each GCP when it is placed to aid in identification later when processing data (see figure 2). 
    • Take field notes of the locations and create a rough map. 
      • Field ID number
      • Last 3 digits of the serial number
      • Include a location description
  • Kept running > 45 minutes
    • The GCPs need at least 45 minutes to take multiple position readings and increase their accuracy.
  • GCPs off
    • Before moving a GCP, it is important that it is off. Press the red power button and wait until the light stops flashing then collect it. 
  • Collected in reverse order
    • Make sure to collect the GCPs in reverse order that they were distributed in. 


Flights:
            Once all the GCPs were laid out, our group rejoined the main group and the M600 was launched. Professor Hupy flew the first flight and I flew the second flight. Both flights went smoothly with no issues. Video 1 below shows the the begging of the first flight.
Video 1: M600 Beginning of Initial Flight

            Once these flights were completed, Professor Hupy decided to gather some Geospatial video of the road leading to the forest. Three passes following the road were performed by Lucus Write then the M600 was landed,packed away and the GCPs were collected. 

Conclusion:
            Overall, the day’s flights were a resounding success and the mission went flawlessly. We will have to see how the data turns out once it is uploaded.