1. A missile system comprising: (a) a missile; (b) a seeker located at a nose portion of said missile, said seeker comprising an electro-optic imaging sensor; and (c) a control arrangement for steering the missile along a flight path to a target, characterized in that the missile system further comprises: (d) a navigation subsystem receiving images from said imaging sensor, said navigation subsystem being configured to: (i) co-process a plurality of said images from said imaging sensor to derive ego-motion of said missile relative to a region viewed by said imaging sensor; (ii) derive from said ego-motion a calculated target direction from said missile to a target.