The Joint Service Endgame
Model
is a computerized simulation used to evaluate the kill
probability attained by a missile warhead or projectile
detonating near an airborne target. The JSEM computer
simulation program evaluates terminal effectiveness of a
fragmenting munition against a target. Terminal effects (also
known as endgame) occur after simulated acquisition, tracking,
fly out, and intercept phases. These early phases of the
endgame input are accomplished with other simulation models,
and their output is used to define initial conditions of
dynamic missile orientations to the target (velocities,
angles, and miss distances) and fuzing time. The JSEM source
code is contained in six modules and consists of more than
30,000 lines of code and comments in just under 200
subroutines and functions.
JSEM calculates endgame kill
probabilities from direct hit, blast, and fragments. JSEM uses
probability of kill given a hit (Pk/h) table output files from
the SURVIAC vulnerability model the Computation of Vulnerable
Areas Tool (COVART) is the most common method of obtaining
vulnerability input to JSEM. JSEM requires a collection of
information to generate effectiveness data: target skin
contours, blast contour, fault tree, component location and
damage option, missile warhead size and fragment
characteristics, and encounter geometry. This provides the
shielded vulnerable area to JSEM without direct simulation of
all the intervening shielding components. JSEM is also capable
of performing a basic fuzing algorithm, which requires fuze
characteristics.
There are several files that are produced with each run
and several files that can be turned on if desired. The files
that are produced with each run consists of a file containing
the input and output files used for the run, program control
records, subsets of weapon and target system physical
description, and some vulnerability, and a file that sets up
the geometry for each encounter.
The only output file that is created with each run contains a
summary of which files were opened and a probability of kill
averaged over the total number of encounters. Another file
containing detailed information including diagnostics, sorting
of input data and probability of hit and kill per detonation
and encounter pass. Other optional files contain last
component hit versus the detonation position, probability of
kill versus detonation for each encounter, probability of kill
summary, a list of subroutines accessed during the run and
fragment intercept coordinates.
