BATTLE GROUP VULNERABILITY
(BGV)
LEARNING OBJECTIVES: Interpret BGV
graphic depictions and identify their uses.
Identify applications, limitations, and
assumptions. Analyze an example of the BGV
display.
BGV provides estimates of the vulnerability of the
various platforms in a battle group to a specified
electronic support measure (ESM) system under
varying environmental conditions. The vulnerability
estimate for an individual platform is expressed as the
maximum intercept range of all active emitters on the
platform. A graphic depicting the vulnerability of the
battle group is displayed. Intercept ranges for
surface-to- air, air-to-air, and air-to-surface can be
calculated.
APPLICATION
The emission control (EMCON) planner uses BGV
to assess the effectiveness of EMCON plans and to
optimize platform position. The object is to minimize
the battle group’s vulnerability to counterdetection.
LIMITATIONS AND
ASSUMPTIONS
The restrictions as well as the principles taken for
granted in running the BGV program are as follows:
. Make sure the environment selected from the
refractivity data set is indicative of the location and time
of interest. BGV is range- and time-independent.
. The maximum intercept range output is limited
to 1000 km (541 nmi). The atmosphere is usually not
horizontally homogeneous over these great distances.
l BGV doesn’t account for absorption of
electromagnetic (EM) energy, In general, the
absorption of EM energy by things such as oxygen,
water vapor, fog, rain, snow, and soon, adds little to the
propagation loss.
Refraction is considered the main
factor in transmission.
. BGV is valid for frequencies between 100 MHz
and 20 GHz.
. Sea-reflected interference is also considered only
if the receiver or emitter is below 100 m.
. The effects of surface-based ducts are considered
to dominate any contributions from the evaporative
duct.
l BGV assumes the emitters are radiating at peak
power.
l The probability of detection associated with the
output ranges depend upon the probability of detection
associated with receiver sensitivities.
l If you are attempting to verify ESM intercept
ranges achieved by your own receiver, remember that
BGV outputs maximum intercept range. If a platform’s
emitters are not turned on at that range, there will be
nothing to intercept.
FUNCTIONAL DESCRIPTION
BGV computes the maximum ESM intercept range
(ESMR) of an emitter. ESMR is computed only if the
emitter’s frequency falls within one of the frequency
bands of the receiver.
Figure 7-2 shows an example of the BGV display.
The center of axis corresponds to the formation center,
and the top of the screen is north. Each platform’s
location is marked by an X. The shaded circle around
each platform has a radius equal to the longest ESMR
associated with that platform. The shaded area as a
whole represents the battle group’s area of vulnerability
to ESM counterdetection.
ELECTROMAGNETIC PATH LOSS
VERSUS RANGE (LOSS)
LEARNING OBJECTIVES: Interpret LOSS
display parameters.
Recognize optimum
locations and flight paths. Identify limitations
and assumptions.
Explain functional
description.
The LOSS program provides a display of one-way
path loss vs. range or path loss for ESM intercept vs.
range. The ESM systems, radar, communication, or
sonobuoys are prepared for LOSS by the EMFILE
maintenance program. The EM system’s transmitter
heights (if airborne) and the target or receiver heights
are entered during the program run. The RDF is
presented for refractive environment selection each time
LOSS is run.
7-4
