THE CAMEL PROJECT - CHARACTERIZATION AND CLASSIFICATION OF DUNE FIELDS ON MARS BASED ON EARTH. T. Barata1, P.Pina2,

Introduction: Dunes are common features on planetary surfaces where unconsolidated material is present in abundance and responds to an atmosphere capable of producing significant winds. Wind is the most important erosive agent on present-day Mars, and the availability of large amounts of loose sand and dust provides conditions for the existence of dune fields all over the planet. They are the most frequent aeolian features on the Martian surface and they constitute a unique record of the interactions between the atmosphere and the planetary surface, so their study may contribute to understand the way the climate has evolved along the history of Mars [1]. Identification and characterization of dune fields on Mars started in the 1970s, on a global scale. Visual data from the Viking mission orbiters consisted mostly of images whose spatial resolution did not allow for detailed studies of the identified fields, which were seen to cover large (kilometric) areas of the surface. The instruments currently orbiting Mars, however, acquire digital images with much better spatial resolution. New imagery from Mars, with higher spatial resolution (up to 25 cm/pixel for the HiRISE camera) and better temporal coverage, can lead to more detailed studies of dune fields, including the study of their evolution through time, which should be more evident for small-scale structures [2]. The Mars Dune Consortium is a group of planetary scientists whose stated intention is to create a catalogue containing all dune fields identifiable on the surface of Mars. According to them, a huge effort and cooperation among planetary scientists is necessary to enlarge the database, deepen the knowledge on these features and improve our understanding of the fundamental processes underlying their formation [3]. The Mars Digital Dune Database (MDDD) was initiated [4], mainly using THEMIS IR images (100 m/pixel) and including dune fields of medium to large dimensions. When images with better quality (THEMIS VIS and MOC NA) covering dune fields already identified are available, the members of MDDD perform a classification based on the classic terrestrial scheme [5] and calculate some characterizing parameters. Thus, the MDDD offers the opportunity to study the global distribution of aeolian dune fields on Mars, both in regional and global contexts, permitting the establishment of correlations between climate, sed-imentary and aeolian processes and evaluating the wind