Field Notes - Platform: Yuneec H520

For this lab, it was meant to make a session with a Yunecc H520. We started by splitting up into two groups. One group walked to the flying area to lay out the Ground Control Points. The second group stayed with Professor Hupy and the platform and went through assessment of altitude, and the pre-flight steps that included the sensor, accelerometer and compass calibrations. We were instructed to fly a little bit outside the chosen area to avoid distortions. Regarding overlapping images, generally, a 75% frontal and 60% side overlap is considered to be adequate. However, since we were in a forest, even if it was not that dense, an 85% frontal and 70% side overlap would be safer. Below is some initial metadata.

Location: Martell Forest
Date/ Time: 3/26/2019, 11:20 am EST

Platform: Yuneec H520 

Sensor: E90
GCP: AeroPoint markers
Altitude: 80 meters
Weather/ conditions: Clear skies, little wind, 50 degrees F, 0% precipitation
Datum: NAD 83 2011

Pilot: Lucas Wright 

Figure 1: Professor Joseph Hupy engages the UAV.

Figure 2: Yuneec H520 

We powered up the transmitter and programmed the flight-path into the software. We would start to fly at 80 meters in altitude with the sensor in nadir view (straight down). Thereafter the idea was to fly with an oblique angle of 45 degrees. After starting the platform we switched the transmitter's connection to the platform itself.

Figure 3: The platform's joystick.

Figure 4: Pre-flight setup

GCPs are used to increase the overall accuracy of a model. These are marked locations in the area of interests that utilized GPS for their exact location. When collecting images with UAS, the synchronization between the GPS and the images can have bad quality. For GCPs to be effective one needs a minimum of 3 points, but in our case, we used 9. More than 10 does not contribute to increase accuracy. Using GCPs and especially with them well distributed helps increase accuracy. The accuracy for these AerioPoint markers are 2-3 centimeters.

Figure 5 The GCPs, well distributed around the area.

Figure 6: Before take off

Unfortunately, the UAV came down after just some seconds flying and we only brought one platform. This was probably due to some partial disconnection between the battery and the platform, but sure the battery was loaded. This is something that can happen in the realm of UAS but in order to minimize human error and for it not to happen a checklist should always be up. If possible, let the flight coordinator help the operator with the checklist. A general checklist may include many of the features below:

Checklist
PRIOR TO TRAVEL
⬥Location confirmation
▢ Confirm location with client(s)
▢ Confirm date with client(s)
▢ Confirm availability of observer
▢ Minimum takeoff/landing area confirmed (50 ft radius)
▢ Obstacles are noted and mapped

⬥Permission to fly
▢ Property owners’ approval
▢ FAA Part 107 approval (if flying <5 miles of airport)
▢ NOTAM filed (if flying <5 miles of airport)
▢ Participants’ approval (if flying over people)
▢ Part 107 waiver filed and approved (if necessary)
▢ Check current NOTAMs for flight area
▢ Area clear of aircraft

⬥Weather
▢ Weather report printed
▢ Temps: 32°-104°F
▢ Wind: 0-22 mph
▢ Visibility: >3 sm
▢ Ceiling: >500 ft

⬥Aircraft
▢ Software updated
▢ Repairs made from previous flight
▢ No damage to aircraft
▢ SD card formatted
▢ Spare propellers packed
▢ Emergency repair kit packed

⬥Controller
▢ Software updated
▢ Fully charged

⬥Batteries
▢ Fully charged


PRE-FLIGHT
⬥Set up
▢ Verify area clear of obstacles
▢ Measure area EMI
▢ Place takeoff/landing pad
▢ Observer present

⬥Power up
▢ Remove gimbal cover
▢ Place aircraft on launchpad
▢ Power up controller
▢ Power up aircraft
▢ Confirm controller-aircraft connection
▢ GPS: >8 satellites
▢ Calibrate IMU
▢ Calibrate compass
▢ Confirm video feed
▢ Confirm gimbal movement

⬥Failsafes
▢ Return to home: Battery level <20%
▢ Return to home: Lost link
▢ Land in place: GPS signal lost


IN FLIGHT
⬥Takeoff
▢ Select flight mode
▢ Select manual/automatic takeoff
▢ Takeoff

⬥In Flight
▢ Climb to mission altitude
▢ Proceed to mission destination
▢ Maintain visual line of sight
▢ Monitor wind speeds/heading
▢ Monitor aircraft GPS location
▢ Monitor battery percentage
▢ Complete mission

⬥Landing
▢ Verify clear path home
▢ Select manual/automatic landing
▢ Land safely


POST FLIGHT
⬥Power down
▢ Power down aircraft
▢ Power down controller
▢ Remove props
▢ Secure gimbal

⬥Data collection
▢ Download photo/video data
▢ Record flight time in logbook