“…It can be done by integrating the INS with an auxiliary navigation subsystem and forming, e.g., such combined system as a visual-aided INS (see, e.g. [22]), which provides the landmark-based estimation of position and velocity. In this case, the extended Kalman filter is proposed to be applied to fuse inertial measurements with camera observations of the socalled map landmarks, i.e., features (e.g., craters) whose coordinates can be found from a map of the landing site, which is available a priori.…”