The present invention relates to electro-optic guided missile systems and, in particular, it concerns systems and methods providing enhanced navigation capabilities based on ego-motion processing of seeker images. The missile system comprising: a missile;a seeker located at a nose portion of said missile, said seeker comprising an electro-optic imaging sensor; and a control arrangement for steering the missile along a flight path to a target, characterized in that the missile system further comprises: a navigation subsystem receiving images from said imaging sensor, said navigation subsystem being configured to: 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;derive from said ego-motion a calculated target direction from said missile to a target.