Game Development Reference
In-Depth Information
Missiles
Now that we have learned the basics of modeling the physics of rockets, let's spend a little time
exploring the physics of missiles. The word “missile” has several definitions, but in this chapter
a missile is defined simply as a rocket that is used for military purposes. Missiles can be large or
small. Intercontinential ballistic missiles (ICBMs) can be as large as the rockets that are used to
put satellites into orbit. Anti-aircraft or antitank missiles are relatively small, highly maneuver-
able rockets.
Missiles are often characterized by what they are launched from and where they end up.
An
air-to-air missile
is fired from an airplane or helicopter and is meant to shoot down another
airplane or helicopter. A
surface-to-air missile
is fired from the ground and aimed at a target
that is in the air. A
surface-to-surface missile
is launched from the ground at a ground target.
An
air-to-surface
missile is fired from air at a target on the ground. Figure 11-10 displays a
picture of a Sidewinder air-to-air missile.
Figure 11-10.
The Sidewinder air-to-air missile (Photo courtesy of the U.S. Air Force)
No matter what their purpose, missiles are in essence rockets and are governed by the same
mathematical equations we derived for rockets earlier in this chapter. The only additional
information needed to the position and velocity of a missile is the geometric and engine
performance data specific to the missile.
Missile Guidance
Another difference between a missile and a rocket used to lift a satellite into orbit is that the
missile is trying to hit something. Once a missile is released and its engines have fired, it needs
a way to track its target. The part of the missile that tracks a target is called the
guidance system
.
There are several guidance system technologies in use today. An
infrared
, or heat-seeking,
guidance system homes in on the infrared energy (heat) generated by the target. Some missiles
have a
laser seeking
guidance system whereby the missile homes in on a laser spot that is
projected onto the target.
Radar tracking
guidance systems use radar signals to home in on
their target.