One example is the World Wildlife Fund, WWF, that owns a dozen of Freyas that they use for locating rhinos and elephants, as well as looking for poachers. The thing with looking for these animals is that they are easier to find during dusk and dawn. It is also so that due to the background heat radiation of the African savannah the only time you can fly a thermal sensor with any chance of success is during late night and dawn.
What do we mean by “night”?
Let us start by using a definition from the Federal Aviation Administration (FAA) in the US. Night means the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the Air Almanac, converted to local time.
Problems with UAV night flight
We have a few considerations when flying at night.
- We can’t see the plane
- Low visibility with regards to the surroundings
- Lack of a UAS Traffic Management, UTM
It would be difficult to operate a small unmanned aircraft system during the night unless the small unmanned aircraft has anti-collision lighting visible for at least 3 miles, or 4.8km.
Preferably we would like to know what direction the UAV is pointing to in the darkness of the night. The answer to that question can be found within manned aviation.
In addition to this we would like to introduce a strobe function, as we have found that the strobe function makes it even easier to detect and locate the UAV.
2. Collision avoidance
In a previous blog I stated that collision avoidance in a fixed wing UAV was a bit of a gimmick (and explained my position). I also stated that the exception was during landing and takeoff, where lower altitudes are a given. And of course, with no visibility of the surrounding area, during the night, it would be a good thing.
A UAS Traffic Management, UTM, system for low-altitude airspace may be needed. According to NASA, a UTM system would enable safe and efficient low-altitude airspace operations by providing services such as airspace design, corridors, dynamic geofencing, severe weather and wind avoidance, congestion management, terrain avoidance, route planning and re-routing, separation management, sequencing and spacing, and contingency management.
No doubt several of these features would be of help in a night flight situation. Especially if flying closer to civilization.
One of our Freyas have already been approved for night flight in the US, utilizing anti-collision lighting. That said, there is still a lot of improvement that can be made, and work is ongoing.
Roger Ohlund, CMO SmartPlanes