High precision landing site mapping and rover localization for Chang’e-3 mission

Abstract

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.

Bulk Density of the Lunar Regolith at the Chang'E‐3 Landing Site as Estimated From Lunar Penetrating Radar

“…As an example, if rock depth increases from 3.0 to 4.0 m, the 11% relative error caused by a 20% uncertainty in antenna height would reduce to 8%. High‐resolution topography data generated from CE‐3 landing camera show that the landing site is relatively flat, with a slope generally less than 5° (Liu et al, ). Therefore, it is expected that surface slope would not produce any significant error in the estimated relative permittivity.…”

The 3‐D geological model around Chang'E‐3 landing site based on lunar penetrating radar Channel 1 data

“…After removing the topographic signature, which is less than 2 m in elevation differences along Yutu's path [Liu et al, 2015], the thicknesses ( Figure 4) and depths ( Figure 5) of the strata were calculated from depths of prominent reflectors (e.g., interface I in Figure 2) at all reboot locations. A continuous distribution of thicknesses and depths was estimated using kriging interpolation.…”

Rock size-frequency distribution analysis at the Chang’E-3 landing site

“…They found that the candidate landing area was relatively flat, with a slope of less than 15°. Liu et al (2015) presented a method for high-precision topographic mapping with multi-source data. Analysis of the geomorphology surrounding the CE-3 landing site shows that the landing area and its surroundings are typical lunar mare with flat topography .…”