Remote-sensing images of Mars contain rich information about its surface morphology, topography, and geological structure. These data are fundamental for scientific research and exploration missions of Mars. Prior to China's first Mars exploration mission, data from six advanced optical imaging systems of different missions in the Martian orbit was used to generate Mars global/near-global image datasets with spatial resolutions better than 1 km.

This study used the bundle adjustment technology to optimize the original orbit measurement data by treating Mars as a unified adjustment network, reducing the position deviation between individual MoRIC images to under 1 pixel, and achieving pixel-level “seamless” global image mosaicking.

Brightness and color consistency of the global images was ensured through color correction and global color uniformity. The true colors of the Martian surface were measured using the MMS onboard the Tianwen-1 orbiter, and a true-color reference for the Martian surface was established for true color restoration.

Through this study, a global color image dataset and map of Mars (Tianwen-1 Mars Global Color Orthomosaic 76 m v1), with a resolution of 76 m and a horizontal accuracy of 68 m was produced and released.