VISION BASED OBSTACLE DETECTION USING ROVER STEREO IMAGES

<p><strong>Abstract.</strong> Vision based obstacle detection using stereo images is an essential way for hazard avoidance and path planning in planetary rover missions. However, due to light condition changes and topographic relief, only partial or sparse three-dimensional points may be derived by image matching and triangulation reconstruction, which is not sufficient for recognizing obstacles. In this paper, we developed a strategy to detect obstacles using rover stereo images by combining both image grayscale information and sparse 3D point information. Experiments were carried out using stereo images captured by navigation cameras mounted on the Yutu rover of Chang’e-3 mission. Moreover, how obstacle localization accuracy affected by the parameters are analysed and discussed.</p>

MINERAL ABUNDANCE AND PARTICLE SIZE DISTRIBUTION DERIVED FROM IN-SITU SPECTRA MEASUREMENTS OF YUTU ROVER OF CHANG’E-3

From geologic perspective, understanding the types, abundance, and size distributions of minerals allows us to address what geologic processes have been active on the lunar and planetary surface. The imaging spectrometer which was carried by the Yutu Rover of Chinese Chang’E-3 mission collected the reflectance at four different sites at the height of ~&amp;thinsp;1&amp;thinsp;m, providing a new insight to understand the lunar surface. The mineral composition and Particle Size Distribution (PSD) of these four sites were derived in this study using a Radiative Transfer Model (RTM) and Sparse Unmixing (SU) algorithm. The endmembers used were clinopyroxene, orthopyroxene, olivine, plagioclase and agglutinate collected from the lunar sample spectral dataset in RELAB. The results show that the agglutinate, clinopyroxene and olivine are the dominant minerals around the landing site. In location Node E, the abundance of agglutinate can reach up to 70&amp;thinsp;%, and the abundances of clinopyroxene and olivine are around 10&amp;thinsp;%. The mean particle sizes and the deviations of these endmembers were retrieved. PSDs of all these endmembers are close to normal distribution, and differences exist in the mean particle sizes, indicating the difference of space weathering rate of these endmembers.

Digital terrain model reconstruction and preliminary scientific exploration planning of the Chang'E 3

At 13:11 (GMT) December 14, 2013 Chang’e 3 (CE-3) successfully landed at 19.51° W, 44.12° N northwestern Mare Imbrium on the Moon, making it China's first planetary mission to land on a celestial body other than Earth. CE-3 explore comprises a lander and a rover. It carries eight scientific instruments onboard, including the descent camera on the lander, and the panoramic camera on the rover. These cameras imaged the topographic features around the landing site. This paper mainly presents the digital terrain model reconstruction techniques for the panoramic camera. Image pairs obtained during the first lunar day are used to reconstructed 3D Digital Terrain Models of 0.02 m resolution near observation points E and S3. The maps have been extensively used to support Yutu operations and strategic planning of the mission. The preliminary scientific exploration planning of the Yutu rover for the second lunar day has been made.