Showing papers on "Trajectory of a projectile published in 1972"

Kinetic energy ring projectile

Abstract: A rotatable airfoil non-lethal sting projectile comprising a hollow closed circular ring wing surrounding a central open area. The projectile consists of an aerodynamic lifting body of a thick ring wing geometry which uses spin imparted to it from a launching means for its gyroscopic stability. The combination of aerodynamic stability characteristics and high spin rate (i.e. above 2,000 rpm) results in a flat trajectory and extended range capability. The projectile is intended as a riot control weapon. Impact is non-lethal, but may be painful. The subsonic launch velocity, the non-metallic light weight structure, the soft resilience, and relatively large size of the projectile avoids serious bodily harm due to impact with a person even at point-blank range.

Projectile trajectory correction system

Abstract: A system for correcting the terminal portion of the trajectory of a projectile in free fall so as to minimize the error between the actual and the intended impact point. The projectile may be an artillery rocket, cannon shell, or a similar ballistic body, which is caused to roll during its free fall trajectory. The intended target or impact point is illuminated by a light source and this light is received at the projectile by a sensor consisting of optics and a plurality of detectors arranged in a plane, and along an annular area. The sensor is made to have a hollow conical field of view, such that the ground area in the vicinity of the target covered by the field of view is reduced as the projectile approaches the target. Thus, when the target appears in the field of view its image will fall on one of the detectors to determine the polar coordinates of the target with respect to the uncorrected impact point. Electronic means are provided for firing a lateral thruster at a predetermined time commensurate with the polar position of the detector that has detected the target image. This will apply a lateral impulse to the projectile to change the trajectory so as to minimize the terminal error.

Determination of Aerodynamic Drag from Radar Data

Abstract: : A method for utilizing point position radar data to determine the aerodynamic drag of a projectile is described. Proof of the method's validity and feasibility is represented by results obtained with flight test data taken for a range firing of the 155mm howitzer with the M107 projectile.

Coriolis Deflection of a Ballistic Projectile

Abstract: The ballistic motion of a projectile in the gravitational field of the rotating Earth is considered. The deflection of the projectile from its azimuthol line of fire due to the rotation of the Earth is estimated by determining its three-dimensional trajectory from a set of three coupled equations of motion. The assumptions leading to this set of trajectory equations are itemized and interpreted. Conditions for the rightward and leftward deflection of the projectile are derived and compared to a recently published result. A straightforward physical interpretation of both leftward and rightward deflections is given.