An interesting article about the use of drones, especially civil ones was published in
the March issue of the German magazine "Spektrum der Wissenschaft" (Spectrum of Sciences).
Written by Todd Humphreys, leader of the Radionavigation Laboratory of the University of
Texas/Austin, and Kyle Wesson, a doctorand there, it sums up legal and technical problems.
Main problem still is, that most intended uses are aimed at the often already congested
airspace in and around cities and that every drone used there would have to be equipped
with some kind of collision avoidance system. Radar systems quite often will be no option
for a great part of the drones, which will be too small to carry such additional loads.
The solution may be the Automatic Dependent Surveillance-Broadcast (ADS-B), expected to
be mandatory for every aircraft, no matter of its size, in the US from 2020 onwards.
The mentioned problem with all existing systems, and even with those currently under
development is, that they aren't resistant against spoofing and not even against
accidentally received signals not meant for them.Whereas a pilot may still be capable
of identifying manipulated signals, the flight control system of a drone has no chance.
Faulty software could be another risk, as was shown on August, the 2nd 2010, when during
a test flight a MQ-8B Fire Scout was flying out of controlin the airspace over Washington
for more than half an hour, not even following the pre-programmed emergency routine,
before the controller regained control. GPS still is a mainstay for controlling drones,
but is known to be relatively easy to jam or spoof, as was demonstrated by the Radio-
navigation Laboratory of the University of Texas/Austin during a staged test over the
White Sands Missile range in June 2012, when a drone was hi-jacked using manipulated
GPS signals. To impeded flight security of drones not even the manipulation of signals
is always necessary, white noise in the frequency spectrum of the GPS emissions may be
enough, as a report about the loss of a South Korean recce drone revealed. The reason
for that drone crashing into its ground station, killing one and wounding two soldiers,
could be traced back to a North Korean jamming transmitter. The proposed uses of small
civil drones for either delivering goods in urban areas, or for surveying of such areas
places them in an enviroment, that may be as dangerous for them, as the airspace over
some Afghan areas for military helicopters ! Just follow the cases mentioned in the
media of pilots blinded by laser pointers, or deliberate attempts to disturb air traffic
with kites and balloons. And in the case of the delivery of your pizza or your Amazon
shipment, the "hunter" actually can expect a worthwhile prey, but even if just shot
down using a kind of childrens wooden catapult maybe inflicting severe damage not only
to the drone, but to persons and properties it crashes on ! The legal problems of civil/
commercial drones flying over private ground and pehaps taking photos or videos are less
dangerous, but nevertheless jsut as difficult to solve. In the sum, we'll probably see
quite a lot of years passing by, before "the sky above is filled with drones" !
(Who is interested can get a scan of the original article (in German language), just send
a PM)
