Aerial Phenotyping: Pre-Flight Checklist

Plan flights, and prepare aircraft and sensor for takeoff.

Flight Planning

  • Track crop growth stages closely, fly in the correct stage for the desired data products.
Plant leaves CANNOT be overlapping for accurate stand counts; in corn, this is typically V2.
  • Fly with sufficient resolution for the smallest feature to be measured.
4P+: from 165ft (50m) altitude, ground sample distance (GSD) is .4in (1cm). For high quality data, flying at an altitude that gives several pixels per leaf is recommended.
  • For Aerial Phenotyping, use the altitude, speed, and overlap settings from the assigned Flight Profile for the crop stage:
Tolerances are increased in cloudy conditions to maintain data quality: lower speed and altitude, and increase side-overlap
  • Create and cache maps on tablet with background satellite imagery for offline use
  • Overfly the field in both dimensions to ensure complete coverage
In the pattern shown below, the North and South field boundaries are imaged in two flight passes. The side-overlap region of the first two and last two flight legs covers the length of the edge.
On the East and West edges, the aircraft overflies the length of the field, giving the aircraft time to stop, turn, and begin a new straight and level pass before imaging the data needed. Images taken in turns with high pitch and roll angles, where the sensor is not pointed nadir, are typically not suitable for map generation.
overfly_edges

Sensor Operation

Minimum 5 minute accumulation time should finish by the time the rest of the equipment is prepped for flight; accuracy will continue to improve the longer the base station is powered on. Do not move the base station after powering on.
  • Inspect aircraft
IMPORTANT: verify the GPS mast thumbscrews are tightened into the top of the aircraft legs. If they come loose and fold down in flight, they will contact the propellers. Verify SlantRange sensor window is clear from debris and loose cables are tied down.
  • Monitor wind and cloud cover, modify flight direction and speed if needed.
  • Power on hand controller and aircraft
  • Wait for solid three lights on AIS indicating RTK fix
If AIS lights are green and blinking yellow, the SlantRange sensor needs additional accelerometer data for its calibration. Pick up the aircraft and rotate, all three AIS lights will begin blinking after a few seconds.
  • Blinking red, blinking yellow, blinking green: sensor is waiting for RTCM messages from base station.
  • Solid red, blinking yellow, blinking green: sensor is communicating with RTK base station.
  • Solid red, solid yellow, blinking green: sensor is in RTK float status.
  • Solid red, solid yellow, blinking green: sensor has reached RTK fix, ready to begin data collection.
GPS reflections on the ground can prevent sustained RTK fix. If after one minute, the sensor remains in RTK float, proceed to start data capture and takeoff. RTK fix will be achieved once airborne.
  • Begin data capture by pressing button on AIS, a solid yellow light will appear for a few seconds indicating camera initialization; wait for blinking green light indicating data capture
  • Begin mission through flight planner