Global Security and Intelligence Studies Volume 2, Issue 1, Fall 2016 | Page 78
Global Security and Intelligence Studies
due to increased ambient noise, it was implemented at the 2015 Boston Marathon
and it can protect mobile targets, as the tool is available for vehicles, such as a VIP
convoy (Abbott et al. 2016, 17; Sathyamoorthy 2015, 88). Unlike some visible defense
mechanisms, it is unlikely a lone wolf would detect or become aware of acoustic sensors
near a target prior to the attack. One significant challenge with this technology is the
internal sound database, which will require updates as companies manufacture new
drone models. Nonetheless, the DroneShield’s ability to identify specific drone models
may cue security forces to recurring instances of a unique drone flying nearby, possibly
probing the perimeter and testing security responses or conducting reconnaissance for
a future attack.
Radar
Radar is one of the most effective methods to detect and track aerial threats,
but this defense mechanism encounters unique challenges when applied to consumer
drones. Air surveillance radar in the United States is ineffective against consumer
drones, as these systems detect and track, but do not interdict, planes moving at high
speeds, as opposed to smaller drones moving at relatively slow speeds (Sathyamoorthy
2015, 88). Installation and maintenance of radar systems can be very costly, explaining
their limited presence in the United States. Some sophisticated radar systems “can see
something as small as a bird flying,” presenting false positives or distinguishing small
drones from birds using precision radar and analytics (Elias 2016, 20; Maddox and
Stuckenberg 2015). Such systems can provide early warning to long-term static targets,
especially with physical standoff in the form of clearings between a facility and its
perimeter fence, but a cost–benefit analysis yields poor results in defending temporary
static or mobile targets. Furthermore, drone operators may fly at low altitudes, below
100 ft, to capitalize on inter-visibility lines created by surrounding terrain to block
line-of-sight required for radar detection (Elias 2016, 20). Radar systems are not the
most feasible or easily implemented methods to defend against lone wolves operating
an explosive-laden drone, providing a false sense of security for sites protected by a
dense array of radar systems.
The Human Eye
The naked eye remains the most reliable and practical defense against an
explosive-laden drone. Ironically, no technical asset detected or brought down the
consumer drone that landed on the White House lawn; instead, “a Secret Service officer
standing guard” spotted the drone (Leonnig and Whitlock 2015). A combination
of human senses provide a redundant means to identify and locate drones, such as
seeing a drone’s shadow on the ground or hearing a drone overhead. In Iraq, where
radars “intentionally eliminate slow-flying targets on or near the ground” to prevent
overtaxing tracking systems, human eyes are also “the most effective means of detecting
such slow-flying threats,” such as consumer drones (Gormley 2003, 8–9). Proving to
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