Abstract: A method is provided for determining fratricide probability of projectile collision from a projectile launcher on a platform and an interception hazard that can be ejected or launched from a deployment position. The platform can represent a combat vessel, with the projectile launcher being a gun, the interception hazard being a missile, and the deployment position being a vertical launch cell. The projectile launcher operates within an angular area called the firing zone of the platform. The method includes determining the firing zone, calculating an angular firing area, quantifying a frontal area of the interception hazard, translating the resulting frontal area across a flight trajectory, sweeping the projectile launcher to produce a slew angle, combining the slew and trajectory, and dividing the combined interception area by the firing area. The firing and interception areas are calculated using spherical projection.

Abstract: A method is provided for determining fratricide probability of projectile collision from a projectile launcher on a platform and an interception hazard that can be ejected or launched from a deployment position. The platform can represent a combat vessel, with the projectile launcher being a gun, the interception hazard being a missile, and the deployment position being a vertical launch cell. The projectile launcher operates within an angular area called the firing zone of the platform. The method includes determining the firing zone, calculating an angular firing area, quantifying a frontal area of the interception hazard, translating the resulting frontal area across a flight trajectory, sweeping the projectile launcher to produce a slew angle, combining the slew and trajectory, and dividing the combined interception area by the firing area. The firing and interception areas are calculated using spherical projection.