Week 3: GCP at Martell Forest

 Field Report

Week 3: 9/7/2020

Martell Forest mission brief:

I met Aish, a PhD student in forestry here at Purdue, at Martell Forest today. Her research is related to the missions we will start flying later this month to hopefully achieve species and genotype level identification with UAS collected data. 

The mission today will involve flying the DJI Matrice 600 at different altitudes and seeing how this may affect the quality of the data collected. Ten AeroPoint GCPs will be used to help with the accuracy of the data. The mission area consists of 10-12 year old precision planted red oak trees which have been professionally maintained (Figure 3.1).

Figure 3.1: The mission area - precision planted and regularly maintained red oak plot

Placing the AeroPoint GCPs:

The Propeller Aero AeroPoint GCPs (ground control points) add a level of GPS accuracy to the data that would otherwise be unattainable from the UAS alone. These consist of foam target-like squares that contain the GCP chip embedded in their core. The idea is to lay these down strategically through the area flown such that once the data is retrieved these points can be identified and linked with the data collected. To set these up, one simply has to lay them down in areas of the mission that are visible from the sky and away from obstructions that could redirect GPS signals. Once the mission is complete, the AeroPoints must be retrieved in reverse order in which they were laid down. For this reason, I sketched out a map of our target area for reference (Figure 1). As seen in the sketch, we made sure to space the GPS evenly throughout the mission area. AeroPoint 10 was placed under some light coverage to test the limits of the technology. The effectiveness of this AeroPoint will have to be determined at a later time.

Figure 3.2: Rough sketch of mission area for GCP location reference.

 DJI Matrice 600 flight:

As a class, we were able to do 3 flights today. Initially we had planned for each flight crew (4 total) to do a flight including everything from setup to teardown but we quickly realized this schedule would not be able to accommodate all groups flying within the given time frame. Thus, my group did not end up flying today but we will be first to fly next week. The flights we were able to record were flown at 500ft, 400ft and then 300ft. The M600 setup consisted of: 

System: DJI Matrice 600

Sensors: Zenmuse XT2 (RGB & thermal)

   Sony α6000

Infinity focus

Aperture: F3.5

Shutter: 3200

Flight info:

Flight 1

Altitude: 500 ft

                Takeoff: 1116

Landing: 1123

Duration: 7 min

Flight 2

Altitude: 400 ft

                Takeoff: 1208

Landing: 1216

Duration: 8 min

Flight 3

Altitude: 300 ft

                Takeoff: 1237

Landing: 1247

Duration: 10 min

Figure 3.3: The M600 in action