THE MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION MOSCOW STATE UNIVERSITY OF GEODESY AND CARTOGRAPHY (MIIGAIK) MIIGAIK Extraterrestrial Laboratory 6 March 2013 The International Colloquium and Workshop "Ganymede Lander: scientific goals and experiments" D. Zhukov (1), A. Zubarev (1), I.Nadezhdina (1), J. Oberst (1,2) (1) MIIGAIK MExLab, (2) German Aerospace Center (DLR)

Exploration of Ganymede 1_N DATA/ _003478/ LOR_ _0X630_ SCI_1 1239r C MissionFlyby yearCameraNumber of images Resolution, km/pix Voyager-11979VG-ISS Voyager-21979VG-ISS Galileo GO-ISS Cassini ISS New Horizons 2007LORRI Highest resolved images of Ganymede from the missions: Voyager-1Voyager-2GalileoCassiniNew Horizons

Previous studies Control Networks: Dimensions: two-dimensional (x, y) Images: 302 VOYAGER 39 GALILEO 1921 points from VOYAGER images 200 points from GALILEO images Radius of Ganymede: km Author: RAND, 1998 Map: Projection: Mercator and Polar stereographic Reference surface: Sphere with radius км Scale: 1 : (±57° latitude) Resolution of images included in the map : 0.3 – 30.0 km/pix Author : USGS, 2002

New data available after previous studies: more Galileo images available improved JPL orbit model available for Galileo use nominal Ganymede rotation model and reference system new point measurements and analysis

~ 12 months 1.Control point network generation: - image selection - obtaining exterior orientation - tie-point measurements 1.Control point network generation: - image selection - obtaining exterior orientation - tie-point measurements  Adjusted exterior orientation  Parameters of Ganymede’s figure  Adjusted exterior orientation  Parameters of Ganymede’s figure 2. Generation of Digital Terrain Model (in manual or automatic mode) 3. Orthorectification of images 4. Creation of global mosaic Processing scheme:

ParameterValue Number of points 1960 Total number of images229 Galileo images 117 Voyager-1 images 39 Voyager-2 images 73 Statistics and results from bundle block adjustments ErrorX, kmY, kmZ, km Minimum Average Maximum Accuracy estimation of control point coordinates

Scheme showing resolution of images used for CPN

Distribution of control points through Ganymede’s surface

Control point network visualization

Color images Galileo`s color image by automatic coregistration. VIOLET 2100GREEN 2200RED 2122

New map of Ganymede

Conclusions We have generated a new 3D control point network (CPN) for Ganymede We have used larger number of Ganymede images than were available before, resulting in a more rigid network We benefit from improved orbit data for Galileo Our network provides reliable coordinate knowledge, e.g. for spacecraft navigation or a landing mission Our CPN may also provide navigation support for JUICE and the Russian Ganymede lander&orbiter mission Using our software, it is possible to make quick updates of the network as new images or improved rotation models become available We are still working on shape parameters… Collaboration with European JUICE mission highly appreciated!

Thanks! 2013 THE MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION MOSCOW STATE UNIVERSITY OF GEODESY AND CARTOGRAPHY (MIIGAIK) MIIGAIK Extraterrestrial Laboratory