This paper deals with an environment recognition system which is suitable for small-sized autonomous exploration rovers working on a planet far from Earth. The recognition system consists of a scanning type laser-range-finder and attitude sensors. Because rovers equipped with the proposed system can continue to move on terrains, the system makes it possible for a small sized rover to traverse as a long distance as large rovers under a restriction on its limited mission duration. In this paper the performance of the proposed system is evaluated in both numerical simulations and experiments, considering the effects of sensor errors. Moreover, methods to evaluate estimation accuracy for environmental recognition techniques and to estimate the slip rate of moving rover in short time intervals are introduced.