165 SRC images camera mounted on the Mars Express spacecraft (medium resolution of 24.3 m/pixel), and 16 the images obtained by the Viking Orbiter spacecraft (medium resolution 18,7 km/pixel) constructed a new geodetic control network of Phobos consisting of 800 points. Were received rectangular coordinates of control points in three-dimensional objectivistically coordinate system and the coordinates of the photographing centers for the used images. While the mean accuracy of the control network is 12 m, the lowest errors correspond to the near side of the satellite, and the greatest characteristic of the far side, where it was used mainly Viking Orbiter image.
Based on the created reference network:
• fixed the parameters for the triaxial ellipsoid that best describes the moon's surface;
• constructed a digital elevation model with structural lines, including 106 000 points measured in the stereo mode manually (Fig. 2, 3);
• orthorectification of images and built a global mosaic of Phobos on a triaxial ellipsoid (Fig. 4);
• studied the Phobos libration.
Fig. 1. Example images of Phobos obtained by Mars Express spacecraft (ESA/DLR/FU)
Fig. 2. The measure points in stereo. Performed in digital photogrammetric system "PHOTOMOD" software
Fig. 3. Three-dimensional model of Phobos with the structural lines that were built in MExLab manually by stereo images. Contains 108 thousand manually measured points.
Fig. 4. Triaxial ellipsoid orthoimage of Phobos
Fig. 5. 3-D Model of Phobos, built in MExLab