Advanced visual localization and terrain mapping enhance Zhurong Rover’s Mars exploration

The collaborative research team has improved visual localization and topographic mapping techniques that allow China’s Zhurong rover to navigate and carry out scientific research on Mars. These technologies played a key role in the success of the Tianwen-1 mission, China’s first independent interplanetary exploration effort.

This study was published in the IEEE Journal of Selected Topics of Applied Earth Observation and Remote Sensing. The researcher is affiliated with the Institute of Aerospace Information at the Chinese Academy of Sciences and the Beijing Aerospace Control Center.

China’s Tianwen-1 mission, launched in July 2020, aims to map Mars’ surfaces, analyze geological structures, and study the planet’s climate and environment. A key element of this mission was Zhurong Rover, which landed in Plantia, southern Utopia on May 22, 2021.

In this study, the researchers developed several innovations to enhance Zhurong’s navigation system, such as vignette correction and online camera mast calibration technology, improving the quality of images captured by rover navigation and terrain cameras. These enhancements allow for the creation of high-resolution 3D terrain maps with centimeter-level accuracy, which is important for obstacle analysis and rover path planning.

Additionally, by integrating cross-site visual localization and digital orthophotomap matching, the researchers refined the rover location to 0.50% accuracy compared to the traverse length, which is significantly better than the 3.11% accuracy of the rover dead rechampion system.

This study shows that Zhurong Rover traveled a total distance of 2,009 meters. This inconsistency was caused by wheel slippage due to the downslope trend of the traverse, highlighting the importance of precise localization to understand the movement of Mars rovers.

Additionally, high-resolution topographic maps facilitated detailed analysis of geological features such as lateral Eurian ridges and impact craters, providing valuable insights into Mars’ geological history and climate evolution.