Ball joint gimbal imaging system with an off-gimbal directional electro-optic component

A ball joint gimbal electro-optic system, comprising:

• a platform;
• a ball gimbal mounted on the platform, said ball gimbal including a socket fixedly mounted on the platform and an inner ball captured within the socket and free to rotate about combinations of three orthogonal axes to point a pointing axis;
• a directional electro-optic element mounted on the platform, off-gimbal;
• optics mounted within the inner ball, said optics having a central axis substantially coincident with the pointing axis, said optics configured to reimage an optical beam from a front optical aperture to a smaller back optical aperture that moves relative to the platform with the rotation of the inner ball;
• a motor configured to apply forces to rotate the inner ball within the socket to point the pointing axis;
• a position measurement device configured to determine the rotational position of the inner ball;
• and
• a relay optics system configured to relay the optical beam from the back optical aperture to the electro-optic element, said relay optics system comprising,
• a first two-axis steering element that is positioned and sized to cover the range of motion of the beam from the back optical aperture across the range of gimbal motion;
• and
• a second two-axis steering element mounted to the platform;
• and
• a controller configured to drive the first and second steering elements;
• wherein said controller is responsive to the rotational position of the inner ball to drive the first steering element to steer the optical beam passing through the back optical aperture into the second two-axis steering element and to drive the second two-axis steering element to tilt the optical beam to align light along a central axis of the electro-optic element substantially with the central axis of the front optical aperture on the inner ball.