Patent ID: 8513580
Filing Date: 2013-08-20
Classification: F41F,F41G,F42B

Abstract:
1. A method for guiding along a ballistic trajectory a mortar projectile fired longitudinally towards a target from a launcher through a muzzle, said launcher equipped with an inertial navigation system (INS), said method comprising: providing a mortar INS for the projectile loaded in the launcher synchronized with the INS; providing a laser emitter and an optical sensor on the launcher directed longitudinally towards the muzzle; providing a laser reflector on an aft-facing surface of the projectile; presetting said mortar INS to an initial reference ground position prior to firing the projectile; emitting a longitudinally directed laser beam from said emitter to said reflector less than one millisecond subsequent to firing the projectile, said reflector reflecting said beam as a reflected signal; receiving said reflected signal to said optical sensor; determining a first in-flight state of ground position, altitude and velocity of the projectile by the INS on the launcher based on said reflected signal; transmitting a correction signal from the launcher to a receiver on the projectile, said correction signal providing said first in-flight state relative to the launcher; resetting said mortar INS at a second in-flight state, extrapolated from said first in-flight state, prior to reaching maximum altitude based on said correction signal; and guiding the projectile to adjust its control fin orientation to thereby engage the target.