Abstract— A fiber optic interrogator has been developed
with software (S/W) that will detect people walking,
vehicles and digging across a 100m swath around a buried
fiber optic cable. These activities cause minute pressure
waves that transmit through the ground to the buried fiber.
The pressure waves then hit the fiber causing minute
changes in the fiber index. Rayleigh backscattering is
extremely sensitive to these index changes. The three
activities are distinguished from each other with S/W and
the activities can be located within a few meters along the
fiber. The temporal frequency of this backscatter allows
discrimination of the targets. The resultant system is
analogous to an array of geophones where the number and
sensitivity of the geophones is programmable. The
interrogator was field tested with 40 Km of buried fiber
providing definitive discrimination of all three target types.
This system was designed for maximum versatility with
S/W controlled variable pulse width to improve target
location, S/W controlled variable pulse rate and data
sampling to optimize storage requirements, and S/W
controlled variable output power to allow increased
sensitivity at longer ranges. The buried fiber GPS
coordinates are correlated with Google maps to allow the
events to be overlaid onto a topographical map. The result
is a color coded real time pictorial of events over the entire
fiber length (>80 Km) fused with a map of the area giving
operators total situational awareness. The entire
interrogator and processing computer have been packaged
into a portable ruggedized 19” rack. Data is transmitted
across an Ethernet connection for analysis at a central
location. This system is suitable for use on any border. For
the US Northern border: There are only 2,200 US agents (4
agents/10Km average). For the US Southern border: there
are 17,659 US agents (56 agents/10 Km average). The
Hyperbox® would reduce the number of required agents by
providing a force multiplier with a few dozen installations
and 24/7 coverage at a price that is the lowest cost/Km of
any other available surveillance technology.