Bearings-only guidance and navigation for in-orbit rendezvous

In-orbit rendezvous is a key enabling technology for many space missions that already enjoys significant heritage. Nevertheless, skin tracking sensors are required to measure the relative range when the target is non-cooperative. These sensors, such as RADAR or LIDAR, require high power to operate at long distances. Since bearing (angular) measurements can be acquired using simple sensors such as a single optical camera, bearings-only rendezvous would significantly reduce the mass and power requirements for these missions. Nevertheless, several challenges arise from the lack of a direct range measurement, which renders the navigation problem instantaneously unobservable. This was first identified in the Naval and Military literature, where it was established that the execution of known maneuvers is necessary to introduce observability to the estimation problem. This results in an intrinsic coupling between the guidance and navigation design, as the guidance inputs determine the achievable navigation performance. In the context of space rendezvous, little research is available treating the impact of observability on the rendezvous trajectory design. This thesis addresses the main issues surrounding bearings-only observability from first principles. Specifically, it develops new theoretical observability analysis and optimization tools which are then used to design a complete guidance and navigation solution which integrates observability optimization within the complete rendezvous trajectory design. All these contributions address the main GNC issues arising from the inherent unobservability of the bearings-only navigation problem, bringing the state of the art one step closer to a fully autonomous in-orbit bearings-only rendezvous mission.