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TRUE-3D VISUALIZATION OF THE MARTIAN SURFACE BASED ON LENTICULAR
FOIL TECHNOLOGY USING HRSC IMAGERY
M. F. Buchroithner ^*, O0. Wälder “, K. Habermann *, B. Kónig *, T. Gründemann *, G. Neukum and the HRSC Co-Investigator
Team "
? Dresden University of Technology, Institute for Cartography, D-01062 Dresden, Germany - Manfred.Buchroithner@mailbox.tu-
dresden.de i
" (HRSC Principal Investigator), Institute for Earth Sciences, Freie Universitaet Berlin, Malteserstr. 74-100,
D-12249 Berlin, Germany - gneukum(@zedat.fu-berlin.de
Commission IV, WG IV/9
KEY WORDS: Cartography, Extra-terrestrial, Planetary, Three-dimensional Visualization, Mars Express HRSC Imagery, Multi-
Line Scanner, DEM/DTM
ABSTRACT:
Following the conceptual idea "from 3D camera to 3D view", the production of true-3D image maps for the glasses-free stereo-
viewing of parts of the Martian surface, is described. The image data have been acquired by the DLR High Resolution Stereo
Camera (HRSC) as a part of the Mars Express Mission of ESA. This multi-line scanner delivers digital multispectral scanner data of
highest quality in a fore, aft and nadir mode, thus offering a perfect data set for true-3D visualization.
A true-colour image-line map in true-3D appears to cover both the requirements of the Mars research community and of the public
best. In order to be able to view the map without viewing aids such as polarisation glasses the decision was made to generate it on the
basis of lenticular lenses.
The present paper demonstrates the workflow from the georeferenced image data set and the DTM to a true-3D visualization. The
technology used is based on the principle of lenticular foils. Micro-lenses on a transparent plastic foil allow the map user to view the
integral of two or more interlaced strips of stereo-mates through this foil with the left and right eye respectively. The calculation of
both the strip width and the interlacing is done by means of commercially available software.
Due to the interlacing of the sub-millimeter strips of the stereo-mates below each lenticular lens and the resulting decomposition in x-
direction the integration of well-designed and easily legible signatures and letterings represent a challenge, both in terms of three-
dimensional modelling and cartographic elaboration. Tests and approaches to overcome various constraints in order to generate
optimized hardcopies are described.
To date, maximum formats of 60 cm x 90 cm oblong and 65 cm x 50 cm upright can be produced.
1. SCOPE
This led to the search of other, more appropriate and also
Based on unpublished studies carried out in the 1970ies and the cheaper methods for the generation of true 3D cartographic hard
1980ies by Manfred Buchroithner, Dresden University of copies. Some years ago first attempts using the so-called
Technology, with probationers who were members of alpine lenticular foil approach have been carried out with quite some
climbing courses, it has te he stated, that roughly 60 % of all success. The positive echo caused by these first thumbnail
map users are noi in the position to spontancously derive specimens made us think of the generation of a larger format
information about the third dimension from topographic maps. maps of high-relief terrain.
This applies particularly to high-relief terrain. Based on the
finding of these studies (which are still intended to be published In preparation of the Mars Express (MEX) Mission which
in the near future) the prime author of this paper has been trying started in December 2003 several terrestrial test flights have
to develop methods which enable the map reader to been carried out. Apart from a test data set of Stromboli Island,
Spontaneously perceive the relief information with the unaided the area around the internationally renowned Alpine Instruction
eyes, ie. without the use of either anaglyph glasses, and Training Centre of the Rudolfshuette of the Austrian Alps
chromadepth glasses, or polarisation glasses. has been chosen for testing (Hauber, E., Jaumann, R., Wewel,
F., Gwinner, K., Neukum, G., Slupetzky, H., 2000). An area of
In a first attempt a high mountain map based on a white-light approx. 90 km? (7.7 km W-E und 11.5 km N-S) has been
transmission hologram ( holo-stereogram) has been produced covered by a high quality data take of the High Resolution
(Buchroithner, M. F., Schenkel, R., 1999; Buchroithner, M. F., Stereo Camera (HRSC) developed by the Institute of Space
2000; Kirschenbauer, S., Buchroithner, M. F., 1999). However, Sensor Technology and Planetary Exploration of the German
it turned out that apart from the need of an illumination with Aerospace Center DLR. This camera is actually a one-to-one
coherent light, the production costs of such high quality pre-runner of the actual camera mounted on the Mars Space
holographic maps are exorbitant. Probe. The imaging led to the production of a first image map.
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