Editing Missile guidance (section)

==== Proportional navigation ====
{{Main|Proportional navigation}}
Proportional navigation (also known as "PN" or "Pro-Nav") is a [[Guidance, navigation and control|guidance principle]] (analogous to [[proportional control]]) used in some form or another by most homing air target [[missiles]].<ref>Yanushevsky, page 3.</ref> It is based on the fact that two objects are on a collision course when the direction of their direct [[Line-of-sight (missile)|line-of-sight]] does not change. PN dictates that the missile velocity vector should rotate at a rate proportional to the rotation rate of the line of sight (line-Of-sight rate or LOS-rate) and in the same direction.