As we sift through all the dreams and nightmares about UAVs, it is clear that drones of all types are most useful in reconnaissance. (This is not surprising, historically this was the first and probably remains the most important use of piloted aircraft and orbital spacecraft.)
Let’s get out of human-centric concerns for a minute and consider one good use for such surveillance, observing wildlife. Stewardship of our dwindling and endangered populations of non-humans is labor intensive and difficult, and we can’t come close to the resources to do it by hand. It is natural to use small aircraft for some kinds of surveys, such as monitoring populations of animals.
This is already in use, e.g., the well named AirShepherd, watching over Elephants and Rhinos.
Large and important animals get a large and complex drone system, a very warlike response to an existential threat.
But there are many species that are endangered not by poachers but by pressures due to loss of habitat. Field biologists need to understand what the animals do in the wild, so we need to unobtrusively watch them. This is a classic activity of filed scientists, and it is quite difficult.
A group at Australian National University and U. Sidney have used small (cheap) UAVs to track radio tagged bettongs (Manorina Melanocephala), small, endangered marsupials. Radio tracking may enable a close understanding of the movements and behavior of these animals, even when they remain hidden in cover and shy of observers. Tracking with a drone is comparatively unobtrusive (as long as the bettongs ignore drones), and can cover a lot of area faster than ground based monitors.
However, radio tracking is done through triangulation, and tracking a moving animal requires many observations be combined rapidly to estimate the position as it moves. In other words, radio reception and detection might be easy, but accurate localization is harder.
Oliver Cliff an colleagues report on their techniques in their recent paper, “Online Localization of Radio-Tagged Wildlife with an Autonomous Aerial Robot System”. They use a small UAV with two antennas that are configured as a multiphase array. The UAV rotates (you know, like a radar dish), to compute a precise position for the signal from the beacon on the bettong. Furthermore, the aircraft autonomously moves to collect a series of estimates of the position. (Details in the paper.)
This is quite elaborate, but pays off because the drone is faster than a human, especially in difficult (for humans) terrain.
The initial experiment is only one UAV and a few animals. It will be more complicated if there are many more signals to track, and if you use multiple trackers. (it would be embarrassing to collide in the air!)
I’m sure this technology is a down market civilian version of things that expensive military crews can do. But it does show that drones are going to be really, really intrusive as they enter everyday life. (If you have a mobile device, you carry a beacon that could be tracked just like the bettongs.)
- Cliff, Oliver, Robert Fitch, Salah Sukkarieh, Debbie Saunders, and Robert Heinsohn, Online Localization of Radio-Tagged Wildlife with an Autonomous Aerial Robot System, in Robotics: Science and Systems. 2015: Rome, Italy.