Cold drone

They are using drones to measure seals in Antarctica. Thats pretty cool.

https://internetofbusiness.com/drones-scientists-antarctica-food-chain/

The higher you go up the food chain, the more you can learn about the ecosystem as a whole. That thinking is behind a project that has seen marine researchers use drones to collect biological samples from whales, and it’s now underpinning similar efforts on land in Antarctica.

Scientists from the US National Oceanic and Atmospheric Administration (NOAA) Southwest Fisheries Science Center are using drones to gather data on the predator that best reflects the health of local fish stocks: leopard seals.

So in short, they place the drone at a fixed height off the ground, and place a known marker, photographing the marker, gives them an accurate scale, and then they simply fly over the seals and take photos.
Long and short of it, they can ascertain the length and weight of the seal within 2% and 4%.
Very cool.

Speaking of cool… I had a chance to fly my drone in the morning a week or so back, everything powered up, I waited for GPS lock and all systems to come on-line. The DJI app gave me the approval to take off, I sent the usual signal and the app reported – ‘Takeoff aborted, battery too cold’.
First time for that message…. The drone had been in the car all night and was cool, so I popped the battery under my armpit for about 5 minutes and took off as usual… But of course, by then, the sunrise light had changed.
So, no harm done, lesson learned. (Or something…. There might have been some swearing at DJI).