The newest concepts of rendezvous missions involving on-orbit servicing tasks and proximity operations have highlighted the need for alternative strategies for the Target's orbit determination. While a cooperative Target is usually a spacecraft equipped with Global Navigation Satellite System (GNSS) sensors and Inertial Measurement Units, and is therefore capable of communicating its state to the Chaser or to the Ground Segment, this does not hold in the case of a non-cooperative Target, like a decommissioned or malfunctioning satellite, an asteroid or a space debris. Angles-only navigation offers a relatively simple and low cost solution to this problem, exploiting a Chaser-mounted optical camera which tracks the Target motion along the entire orbit.