Since we cannot hold them in captivity or ask them to stay still while we get our measuring tape out. So, we use drones (or Unoccupied Aerial Systems, UAS) to fly over whales without disturbing them and collect data on body condition (and behavior).
We hand launch the drone from our research vessel and then a trained and certified pilot flies the drone over the whale at an altitude of about 30m/98ft. We record video of the whale at the surface and underwater, if water clarity allows us to track it, for up to 15 minutes (battery life constraints). After the data has been collected, we process the video data. This analysis involves extracting screenshots of the whale when it is flat and straight at the surface. From these images we conduct photogrammetry, which is the process of making measurements from photographs.