I watched a video on YouTube where someone used the ActiveTrack function of their Phantom 4 on a snowy field. They performed a couple of test that weren’t very successful, so I thought we could discuss how to best use ActiveTrack.

To start off, the P4 User Manual states that you should be careful when using ActiveTrack in snowy environments. This is because the “fluffy” snow absorbs ultrasonic ways that are transmitted by the Vision Positioning System used for the P4’s ActiveTrack function, and affects its stability.

  
  

As we see in the video, the subject being tracked seems to be black without distinctive features, which leads to worse tracking performance. Also, because the snow reflects light, it may affect tracking.

  
  

The maximum speed of the P4 when in ActiveTrack mode is around 10m/s, but the skier is moving at a higher speed than that which means that tracking may be lost. When the skier turns around and changes shape into an “S” shape and exceeds the maximum speed, that might cause tracking to fail.

  
  

Furthermore, as the skier advances on its path, the distance between target and aircraft increases since the aircraft does not automatically decrease its height while in ActiveTrack. If you want to maintain the distance even in situations like these, you need to use the remote controller to descend or ascend the aircraft.

  
  

Finally, at the start of the video we see the aircraft hovering in front of the skier. It can’t track the skier when it is showing its back, since it looks different from the front. So, it’s better to set up tracking from the back when tracking subjects that are running, skiing, cycling, etc.