Vision Based Relative Navigation

Vision is a key technology for the relative navigation of formation flying satellites especially when they operate in close proximity. Indeed, with a vision system the relative position and attitude (usually referred to in the machine vision literature as “pose”) of co-flying satellites can be extracted in real-time. This information can be used either to maintain or change the formation geometry. A crucial aspect affecting vision system design and development is the operation with largely variable lighting conditions and the interference caused by the presence of other celestial bodies in the sensor field of view. This requires the implementation of effective image processing techniques and algorithms by which robust, accurate and reliable pose estimation can be achieved. This chapter provides an overview of sensors, techniques and algorithms enabling the relative navigation based on vision, with specific reference to space missions which have already tested in flight this technology.