Applications to Lunar Remote Sensing - 3D Computer Vision: Efficient Methods and Applications - page 340

Fig. 8.27 Perspective view
of the DEM of the very low
dome NTA3, viewed from
southwestern direction. The
vertical axis is 50 times
exaggerated

The aligned domes making up the NTA examined by Wöhler et al. ( 2007b )are
very low, except for Diana and Grace. As an example, a DEM of the dome NTA3 is
shown in Fig. 8.27 , illustrating its low profile. A summit pit is clearly visible on top
of NTA3.
Lena et al. ( 2008 ) examine the domes Condorcet 1-4 and Dubiago 3, which are
situated in Mare Undarum near the eastern limb of the apparent lunar disk. A DEM
of a part of this dome field is shown in Fig. 8.28 , revealing that the flank slope
of Condorcet 4 is quite steep, while Condorcet 2 and 3 are lower and have a more
pancake-like cross-sectional profile. Under the oblique viewing and illumination an-
gles and low phase angles encountered for these domes, the reflectance behaviour
of the lunar surface largely obeys the Lommel-Seeliger law—for the lunar macro-
scopic surface roughness estimated by Warell ( 2004 ), a value of L(α) = 0 . 9inthe

lunar-Lambert reflectance function ( 8.6 ) is indicated by McEwen ( 1991 ). Hence,
the dependence of the surface reflectance on the incidence angle and in turn on the
surface slope is much less pronounced than for Lambertian reflectance. As a conse-
quence, the heights of the domes in Mare Undarum obtained assuming Lambertian
reflectance are too low by about a factor of two, compared to the values derived with
the lunar-Lambert reflectance law.
The DEM of the large dome complex Mons Rümker shown in Fig. 8.29 bis
constructed by Wöhler et al. ( 2007a ) by employing the described combined pho-
toclinometry and shape from shading technique as a multi-resolution approach to

Fig. 8.28 ( a ) Telescopic CCD image of the domes Condorcet 2-4, situated in Mare Undarum. The
image is rectified to perpendicular view, north is to the top and west to the left . Image credit: P. Laz-
zarotti. ( b ) Perspective view of the DEM of Condorcet 2-4, viewed from southwestern direction.
The vertical axis is 10 times exaggerated, the curvature of the lunar surface has been subtracted