Abstract

A guidance system is shown whereby a spin-stabilized projectile with a "strap-down" seeker may be commanded to fly toward a target by maintaining an inertial line-of-sight rate below a preset limit. To accomplish the desired mode of guidance the projectile here is equipped with a polarization receiver to establish an inertial reference in roll, a strap-down seeker to determine the existing line-of-sight between the projectile and the target during intercept, a signal processor to convert signals out of the polarization receiver and the strap-down seeker into signals indicative of the time rate of change of the line-of-sight angle, corrected for any gyroscopically induced movement of the projectile, a plurality of thrusters in helical channels about the periphery of the projectile and a controller, responsive to the output of the signal processor, to select and fire selected ones of such thrusters to keep the rate of change of the line-of-sight angle below a preset value.