This paper presents the comprehensive results of landing site topographic mapping and rover localization in Chang'e-3 mission. High-precision topographic products of the landing site with extremely high resolutions (up to 0.05 m) were generated from descent images and registered to CE-2 DOM. Local DEM and DOM with 0.02 m resolution were produced routinely at each waypoint along the rover traverse. The lander location was determined to be (19.51256°W, 44.11884°N, 2615.451 m) using a method of DOM matching. In order to reduce error accumulation caused by wheel slippage and IMU drift in dead reckoning, cross-site visual localization and DOM matching localization methods were developed to localize the rover at waypoints; the overall traveled distance from the lander is 114.8 m from cross-site visual localization and 111.2 m from DOM matching localization. The latter is of highest accuracy and has been verified using a LRO NAC image where the rover trajeactory is directly identifiable. During CE-3 mission operations, landing site mapping and rover localization products including DEMs and DOMs, traverse maps, vertical traverse profiles were generated timely to support teleoperation tasks such as obstacle avoidance and rover path planning. Chang'e-3, Yutu rover, landing site mapping, rover localization, descent camera, navigation camera PACS number(s): 96.20.-n, 91.10.Jf, 91.10.Lh, 91.10.Da Citation: Liu Z Q, Di K C, Peng M, et al. High precision landing site mapping and rover localization for Chang'e-3 mission.

The technology and experiments planned for rover localization and landing site mapping in the 2003 Mars Exploration Rover (MER) mission are described. We introduce the Mars global and landing site local reference systems. For global rover localization in the Mars body-fixed reference system, a triangulation can be performed using observations of common landmarks on satellite images and the very first set of surface images. Alternatively, ultra-high frequency (UHF) two-way Doppler tracking technology can determine the location. For localization of the rover in the landing site area, onboard rover localization techniques will be performed in real time. A visual odometry experiment will improve localization by overcoming problems associated with wheel odometry such as slippage and low accuracy. Finally, a bundle-adjustmentbased rover localization method will build an image network acquired by Pancam, Navcam, and Hazcam cameras. The developed incremental and integrated bundle adjustment models will supply improved rover locations and image orientation parameters, which are critical for the generation of high quality landing site topographic mapping products. Based on field tests performed on Earth and Mars (MPF mission data), a relative localization accuracy of one percent of the traversing distance from the landing center is expected to be achieved during this mission. In addition, the bundle adjustment results will also enable us to produce high precision landing site topographic mapping products, including seamless panoramic image mosaics, DTMs, and orthophotos.

This paper presents the initial results of lander and rover localization and topographic mapping of the MER 2003 mission (by Sol 225 for Spirit and Sol 206 for Opportunity). The Spirit rover has traversed a distance of 3.2 km (actual distance traveled instead of odometry) and Opportunity at 1.2 km. We localized the landers in the Gusev Crater and on the Meridiani Planum using two-way Doppler radio positioning technology and cartographic triangulations through landmarks visible in both orbital and ground images. Additional high-resolution orbital images were taken to verify the determined lander positions. Visual odometry and bundleadjustment technologies were applied to overcome wheel slippages, azimuthal angle drift and other navigation errors (as large as 21 percent). We generated timely topographic products including 68 orthophoto maps and 3D Digital Terrain Models, eight horizontal rover traverse maps, vertical traverse profiles up to Sol 214 for Spirit and Sol 62 for

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