The proposed modification is shown schematically in Fig. \ref{fig:dual}. Most of the system remains as before but the corner cube on the Nasmyth table is replaced by a second light injection mechanism, which shines light towards the dichroic. At the dichroic, the light is split, sending one component towards BEASST and and one towards the FTT. To both these systems this light beam appears as a bright “artificial star” which can be switched on and off under computer control. The second modification is to remove the tilt and shear system as this is no longer needed (see discussion below). The vacated space on the Nasmyth table can then be used for the UTM light injection system. All other components of the AAS remain essentially unchanged.