The perturbation calculus in missile ballistics

The calculus of perturbations, as commonly used in exterior ballistics, is modified for application to rocket missiles, that is, to projectiles which experience thrust and lift forces. In this form, the calculus can be used as in conventional ballistics, to investigate the effect of disturbing factors upon a trajectory. In addition to this, it is of considerable value in establishing analytically certain principles of guidance and control. Two examples are given of this: the theory of range control of the German V-2 missile, and a theoretical system of free flight guidance by radio.