Possible to combine image target and world tracking for persistance?

Hello! I'm attempting to create a lens that will use an image target for initial placement of a 3d object, but then persist that object in the same location even if the image target is off screen. Anyone know if something like that is possible, and pointers or tutorials on how I would go about it?

For a more concrete example imagine a large cube with an image target placed in a precise location on one side of the cube. The user walks up and points the camera at the image target and a 3d object is positioned on top of the cube at an exact coordinate relative to the location of the image target. Then the user walks around the cube, and even though the image target leaves the camera view, the 3d object persists and stays in the same location. Essentially combining target and world tracking. Additionally, if the image comes back into view we don't necessarily want to instantiate another 3d object, but we might want to correct the current ones rotation or position if it has drifted while the target was out of view.