Dispersion, Trajectory, and Accuracy Considerations for Scoring Simulated Gun Bursts in Air Combat.

Factors affecting the dispersion of machine gun or cannon projectiles are discussed, beginning with the manufacturing variations of single rounds and finally considering gun-system effects during a burst. Projectile trajectory characteristics are next established with the approximate Siacci equations. These characteristics are linked to the special factors influencing the flight of projectiles fired forward from a moving aircraft. Final dispersion patterns for projectile bursts in air-to-air combat are discussed. The Siacci equations are used to develop partial derivatives which relate projectile impact location errors at the target aircraft to separate, allowable errors in attacking aircraft position, velocity, angular orientation, or angular rate. A statistical technique is used to bounce these geometric parameters as a group. Four selected air-to-air attack scenarios are analyzed by these methods to numerically bound attack aircraft geometric errors. A time-space-position-instrumentation TSPI system providing input data to a computerized cannon-fire simulator would have to achieve these accuracies in attack aircraft geometry so that burst accuracies on target would have the desired, specified values. Author