2D Relative Pose and Scale Estimation with Monocular Cameras and Ranging Chen Zhu ∗ , Gabriele Giorgi † , Christoph G ¨ unther †,∗ ∗ Institute for Communications and Navigation, Technical University of Munich, Munich, Germany † Institute of Communications and Navigation, German Aerospace Center (DLR), Oberpfaffenhofen-Wessling, Germany Corresponding author: Chen Zhu Technical University of Munich (TUM) Institute for Communications and Navigation (NAV) Theresienstr. 90 80333 Munich Germany Telephone: +49 89 289 23435 Fax: +49 89 289 23490 Email: chen.zhu@tum.de This work has been performed in the framework of the project VaMEx-CoSMiC (Valles Marineris Explorer-Cooperative Swarm Navigation, Mission and Control). The project VaMEx-CoSMiC is supported by the Federal Ministry for Economic Affairs and Energy on the basis of a decision by the German Bundestag, grant 50NA1521 administered by DLR Space Administration. Keywords— visual SLAM, visual navigation, relative positioning, cooperative positioning, sensor fusion