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In this study, a stereovision sensor system hardware and an algorithm are developed to be utilized in autonomous satellite rendezvous applications. A two dimensional representative environment is also being developed consisting of omni wheel robots to test breadboard model of the sensor system in a similar proximity operation scenario. The sensor hardware is designed according to predefined requirements keeping the limitations of the satellites. The sensor is able to estimate position, orientation, linear and angular velocity of a target object whose shape and sizes are known a priori. The detection system relies on specific reference markers and extracted BRISK feature points. Both of stereo and monocular vision approaches are used to detect object and estimate its distance, followed by reverse rigid body transformation to estimate the target?s 3D location and orientation. Time difference between two subsequent frames is used for estimating linear and angular velocities. Additionally, a path-planning algorithm is developed to approach target object in an efficient way.

5Zn0.5Fe1.5Cr0.5O4 Nanoparticles (NPs). -The title nanoparticles are hydrothermally prepared from stoichiometric mixtures of NiCl2, Cr2O3, ZnCl2, and FeCl3 in the presence of polyethylene glycol and NaOH (H2O, pH 11.5, 180°C, autoclave, 24 h). The samples are characterized by powder XRD, FE-SEM, FTIR transmission spectroscopy, and conductivity measurements. The material has a giant dielectric constant approaching 10 6 at around 305 K where it exhibits a dispersive phase transition. The frequency and temperature dependent conductivity of the compound is explained by the overlapping large polaron tunneling model. The dielectric properties of the title nanoparticles are promising for technological low-and high-frequency applications. -(TAN, M.; KOESEOGLU*, Y.; ALAN, F.; SENTUERK, E.; J. Alloys Compd. 509 (2011) 39, 9399-9405, http://dx.doi.org/10.1016/j.jallcom.2011.07.063 ; Dep. Phys., Fatih Univ., TR-34500 Istanbul, Turk.; Eng.) -W. Pewestorf 43-011