Fig. 4. Comparison of the Median Absolute Slope (a, c and e) and the Median Differential Slope (b, d and f) as a function of the baseline for (a and b) The Moon, (c and d) Mercury and (e and f) Mars. Two types of terrains, the rough and the smooth, have been characterized for each planet. For each terrain of each planet, an average curve is plotted as well as curves at plus and minus one standard deviation from the average (from a sample of 30–40 individual profiles).