The modern military battlespace is
overwhelmed with radio-frequency
(RF) signals vying for spectrum.
Even without overt RF interference
from enemy jamming, radio stations nearby, or even from civilian
cell phones, co-site interference has
become a major problem for the U.S.
military, one that is growing worse
by the day. Some refer to this kind of
interference as spectral friendly fire.
It can be a problem on military
platforms like surface warships,
“Having multiple command and
control ( C2) capabilities on the same
platform has instituted a greater
awareness of how emitters perform
within the same system and plat-
form,” says Chief Warrant Officer
Jerome J. Foreman, senior strate-
gic spectrum planner at the U.S.
Marine Corps Command, Control,
Communications, and Computers
headquarters in the Pentagon.
“In the broader sense of
co-located systems, the problem is
even more complex due to dense
areas of operations — dense in the
sense of space to operate within
urban populated areas — as well
as the amount of spectrum-de-
pendent systems operating within
a concentrated area,” Foreman
says. “The requirement for multi-
ple spectrum-dependent emitters
within a system will continue to
increase; therefore, it’s likely that
co-site interference will continue to
increase, as well.”
Co-site interference may be most
obvious aboard a Navy ship, where
growing numbers of powerful emit-
ters and receivers crowd together on
The puzzle of
The military relies increasingly
on the RF spectrum for
sensors, and electronic
demands on RF
cause systems in
close proximity to
degrade each other’s signals.
BY J.R. Wilson
The U.S. Navy Northrop Grumman E-2D Hawkeye carrier-based
aircraft must cram together RF voice and data systems, as well as
the plane’s powerful air-search radar system on one small platform.