Fig. 13
From: Science operation plan of Phobos and Deimos from the MMX spacecraft
a Histograms of the altitude above Phobos’ surface. b Plot of cumulative time at or below a given altitude, for QSO-LB and QSO-LC. Vertical lines mark altitudes of 1.0 and 1.5 Phobos radius values, which are related to MEGANE’s measurement requirements. QSO-LB (c) and QSO-LC (d) altitudes as a function of Phobos latitude and longitude of the sub-spacecraft nadir point, colored by altitude. The general latitude range of the Phobos Blue Unit is marked with dotted lines. In all plots, the calculations take the irregular shape of Phobos into account, computing the radius of Phobos at the sub-spacecraft nadir point and ratioing it to the altitude to the surface at that same point