The Multi-Temporal Database of High Resolution Stereo Camera (HRSC) Images: A Tool to Support the Identification of Surface Changes and Short-Lived Surface Processes

Introduction: Image data from Mars transmitted to Earth by spacecraft since the 1970s, for example by Mariner and Viking, Mars Global Surveyor (MGS), Mars Express (MEx) and the Mars Reconnaissance Orbiter (MRO) showed, that the surface of Mars has changed dramatically and actually is continually changing [e.g., 1-8]. The changes are attributed to a large variety of atmospherical, geological and morphological processes, including eolian processes [9,10], mass wasting processes [11], changes of the polar caps [12] and impact cratering processes [13]. The High Resolution Stereo Camera (HRSC) [14,15] on board Mars Express (MEx) covers large areas at high resolution and thus is particularly well suited to detect the frequency, extent and origin of Martian surface changes. Since 2003 HRSC acquires highresolution images of the Martian surface and contributes to Martian research, with focus on the surface morphology, the geology and mineralogy, the role of liquid water on the surface and in the atmosphere, on volcanism, as well as on the proposed climate change throughout Martian history. Thus, MEx has significantly improved our understanding of the evolution of Mars [16-19]. The HRSC data are available at ESA’s Planetary Science Archive (PSA) as well as through the NASA Planetary Data System (PDS). Both data platforms are frequently used by the scientific community and provide additional software and environments to further generate map-projected and geometrically calibrated HRSC data. However, while previews of the images are available, there is no possibility to quickly and conveniently see the spatial and temporal coverage of HRSC images in a specific region, which is important to detect surface changes that occurred between two or more images. We contribute to the systematic processing of High Resolution Stereo Camera (HRSC) nadir (ND) image data with the development of a multi-temporal database of High Resolution Stereo Camera (HRSC) ND images and other planetary ND image data (Fig. 1). The HRSC database will help to globally identify areas with multi-temporal HRSC ND coverage and gives researchers the option to conveniently and easily detect surface changes in planetary image data.