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Logistics, Modeling, Strategy
Salvo Combat Model ..
The
salvo combat model provides a mathematical representation of
anti-ship missile battles between modern
warships. It was developed by Wayne Hughes at the U.S.
Naval Postgraduate School in Monterey and published in
1995. The salvo model describes the basic elements of modern missile combat in a very simple manner. This is similar to how
Lanchester's Square Law provides a simple model of modern gun combat.
Suppose that two naval forces, Red and Blue, are engaging each other in combat. The battle begins with Red firing a salvo of missiles at Blue. The Blue ships try to shoot down those incoming missiles. Simultaneously, Blue launches a salvo that Red tries to intercept.
This exchange of missile fire can be modeled as follows. Let symbol A represent the number of combat units (warships or other weapon platforms) in the Red force at the beginning of the battle. Each one has
offensive firepower α, which is the number of offensive missiles accurately fired per salvo at the enemy. Each one also has
defensive firepower y, which is the number of
incoming enemy missiles intercepted per salvo by its active defenses. Each ship has
staying power w, which is the
number of enemy missile hits required to put it out of action. Equivalently, one could say that each attacking missile can cause damage equal to a fraction u=1/w of a Red ship.
The Blue force is represented in a similar manner. Blue has B units, each with offensive firepower
β, defensive firepower
z, and staying power
x. Each missile that hits will cause damage v=1/x.
The salvo combat model calculates the number of ships lost on each side using the following pair of equations. Here, ΔA represents the change in the number of Red's ships from one salvo, while ΔB represents the change in the number of Blue ships.
ΔA = -(βB - yA)u, subject to 0 ≤ -ΔA ≤ A
ΔB = -(αA - zB)v, subject to 0 ≤ -ΔB ≤ B
Each equation starts by calculating the
total number of offensive missiles being
launched by the
attacker. It then subtracts the
total number of interceptions by the
defender. The number of
remaining (non-intercepted) offensive missiles is multiplied by the
amount of damage caused per missile to get the
total amount of damage. If there are
more defensive interceptions than offensive missiles, then the
total damage is zero; it cannot be negative.
These equations assume that each side is using
aimed fire; that is, a force knows the location of its target and can aim its missiles at it. If however a force knows only the
approximate location of its target (e.g., somewhere within a fog bank), then it may spread its fire across a wide area, with the hope that at least some of its missiles will find the target. A different version of the salvo equations is required for such area fire.
Mathematically, the
salvo equations can be thought of as
difference equations or recurrence relations. They are also an example of
operations research.
A
stochastic (or probabilistic) version of the model also exists. In this version, the
ship parameters listed above are
random variables instead of constants. This means that the
result of each salvo also varies randomly. The
stochastic model can be incorporated into a
computer spreadsheet and
used instead of the Monte Carlo method of computer simulation. An
alternative version of this model exists for situations where
one side attacks first, and then the
survivors (if any) on the
other side counter-attack, such as at the
Battle of Midway.