Knowledge of the interior structure of terrestrial planets can be achieved by studying the changes of their rotation and orientation in time. We simulate the use of time deviations of altimetry crossover positions to infer information on the nutations of Mars and on the librations of Mercury. The analysis is based on the least squares estimator and uses simulated crossover points. The simulations demonstrate that the use of crossover data improves the estimates of the observed libration amplitude and obliquity of Mercury and allows detecting the nutations of Mars.