  Visual Simultaneous Localisation and Mapping (VSLAM) is a well-known problem
in robotics with a large range of applications. This paper presents a novel
approach to VSLAM by lifting the observer design to a novel Lie group on which
the system output is equivariant. The perspective gained from this analysis
facilitates the design of a non-linear observer with almost semi-globally
asymptotically stable error dynamics. Simulations are provided to illustrate
the behaviour of the proposed observer and experiments on data gathered using a
fixed-wing UAV flying outdoors demonstrate its performance.
