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Fig. 1: Digital Terrain Model from Galileo stereo images showing of parts of the nearside northern 
hemisphere including the Humboldtianum Basin (82?E, 57?N) and Mare Crisium (58?E, 18?N). 
Heights vary from -4500 to +2000m. The DTM is represented in a sinusoidal map projection with 5 
km/pixel scale. Note the gaps in the terrain data near the lunar limb and near the terminator, and in 
areas of high sun elevation angles, where the digital image matching failed. 
In the case of Galileo, control points were used exclusively. 
The adjustment involved 49 images, 212 control points, and a 
total of 1004 individual image coordinate measurements. 
Control points were taken from the "Unified lunar control 
network" (Davies et al., 1994), which involves more than 1000 
control points located mostly on the nearside hemisphere. In 
the case of Clementine, the adjustment involved 417 conjugate 
points and 1403 individual line/sample measurements in a total 
of 96 images. 6 control points from an earlier photogrammetric 
study of Clementine data (Oberst et al., 1996) were used to 
support the adjustment. 
Next, we performed several parallel image matching runs 
Involving one reference image and up.to six target images, 
respectively, using an automatic area-based least- squares 
matching technique in image space (Ackermann, 1984; Oberst 
et al, 1996). The matched data were converted to object 
coordinates using the spacecraft position and camera pointing 
data determined in the bundle adjustment using ray intersection 
methods. Finally, the object coordinates were converted to 
line/sample coordinates in an appropriate map projection 
followed by interpolation to form a regular DTM grid. The 
DTMs are normally presented in a sinusoidal map projection. 
4. RESULTS 
Analysis of the Galileo images resulted in a terrain model 
covering much of the nearside northern hemisphere at 2000 m 
grid spacing and 500 m height resolution (see Fig. 1). 
617 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996