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30 September 2009

Goals

  • Conduct atmospheric sensing across boundary layers at the Pawnee National Grassland
  • Correlate in-situ measurements with remote doppler radar measurements

Flight Review

Three flights were conducted at the Pawnee National Grasslands in an effort to sample boundary layer atmospheric conditions. The first two operations were performed in the Southern part of the COA area, while the last was conducted up North. Both of the first flights had problems with the Wifi link, and the UA was not able to successfully track the ground vehicle. The second flight performed as expected, but encountered strong headwinds that forced a remote autonomous landing. Due to a missing connector, the GS was not able to maintain a good Wifi link to any other nodes at distance for all 3 experiments.

NexSTAR-2 Flight 1

    Flight Time: xx.xx mins
    Autonomous Flight Time: xx.xx mins

    Despite working on the ground, the link to the MNR from the UA was disconnected immediately following takeoff, not allowing the Tracker vehicle to command the UA. After 15 minutes of attempting to fix the issue the flight was terminated.

    Data

NexSTAR-2 Flight 2

    Flight Time: xx.xx mins
    Autonomous Flight Time: xx.xx mins

    After having swapped out the MNR in the tracker vehicle, an attempt was made to repeat the first experiment. This time connection to the UA was lost almost immediately after commanding the UA to orbit the tracker. It was determined that some sampling could be performed by moving the tracker 1.5 miles to the North and commanding the UA to fly form the GS to the tracker. The UA was commanded to orbit the GS and the Tracker got into position. The UA was then tasked to fly to an orbit above the tracker. Once above the tracker, an altitude change of 80 m lower was commanded, and the UA was sent back to orbit above the GS. About 1/3 of the way back it was noticed that the propulsion battery had run out. The UA was left in its flight configuration, and the autopilot successfully landed the aircraft in a field adjacent the road. The only damage to the UA was a broken prop and bent nose gear.

    Data

NexSTAR-2 Flight 3

    Flight Time: 32.45 mins
    Autonomous Flight Time: 30.21 mins

    The UA was launched in a strong wind and tasked to orbit about the MNR in the tracker vehicle. The tracker slowly made its way upwind for about 1.5 miles, keeping the UA in sight. The tracker then turned around and drove to a position about 1.5 miles East of the GS. It was determined at this point in time that the UA should return to base. The winds increased at this point, not allowing the UA to make any forward progress. The vehicle was tasked to track a faster IAS, but the propulsion battery cut out about half way back to the GS. The UA was commanded to track a slower airspeed and was allowed to land. No damage was sustained.

    Data