Applications to Lunar Remote Sensing - 3D Computer Vision: Efficient Methods and Applications - page 342

Fig. 8.30 ( a ) Perspective view of the DEM of the dome at the southern rim of Petavius, viewed
from northwestern direction. The vertical axis is ten times exaggerated. ( b ) Cross section in east-
-west direction through the summit pit of the dome. ( c ) Albedo map obtained by ( 3.49 )
could be constructed based on photoclinometry and shape from shading analysis,
which is shown in Fig. 8.29 d.
Lena et al. ( 2006 ) construct a DEM of the dome at the southern rim of Petavius,
situated in a region of non-uniform albedo characterised by a dark pyroclastic de-
posit. It is shown in Fig. 8.30 a. The cross section through the summit pit (cf.
Fig. 8.30 b) reveals that the dome summit is elevated by 240 m above the surround-
ing surface. To the south of the pit, the terrain rises further up to a height of 530 m.
The albedo map of the region covered by the DEM is shown in Fig. 8.30 c, clearly in-
dicating the dark pyroclastic material. The average flank slope of the higher summit
south of the dome amounts to 3 . 1 ◦ , and parts of the flank are even steeper than 4 ◦ .
Hence, it is probably too high and too steep to be of volcanic origin. The interpre-
tation by Lena et al. ( 2006 ) is that the dome is placed adjacent to a hummocky,
impact-related deposit, which is supported by the close proximity of this region to
the rugged inner crater rim of Petavius.
A DEM of the Valentine dome is shown in Fig. 8.31 . This large dome is of pos-
sibly intrusive origin. Its shape is asymmetric; its eastern edge is fairly pronounced
and steep, while the western edge merges smoothly with the surrounding mare sur-
face. The dome surface displays several protrusions and is traversed by a curved
rile.
The approach introduced by Grumpe et al. ( 2011 ) described in Sect. 5.5 , which
relies on the integration of shape from shading with active range scanning data (here:
the LOLA DEM), has been used for the construction of DEMs and albedo maps of
the highland domes Gruithuisen γ and δ , Mons Hansteen, and Mairan T and 'mid-
dle'. The analysis is based on M 3 imagery (cf. Figs. 8.20 a, b, and d) and on the
LOLA DEM with 1 / 512 ◦ nominal lateral resolution, corresponding to about 60 m
at the lunar equator. However, as indicated by the excerpts from the LOLA DEM
showninFigs. 8.8 b and 8.10 b, the true lateral resolution of the LOLA DEM is gen-
erally much lower than the indicated nominal lateral resolution. The obtained DEMs
are shown in Fig. 8.32 as perspective views with the albedo-dependent modelled re-
flectance used as an overlay, where the reflectance model by Hapke ( 1981 , 1984 ,
1986 ) has been used for shape from shading analysis. The albedo maps reveal the
extraordinary brightness of the dome surfaces.