Building a unified elevation data analysis tool in the frame of the CO3D mission

Abstract. The CO3D mission, launched in July 2025, aims to reconstruct the Earth’s continental surfaces in 3D. Assessing the quality of the resulting digital surface model requires an inter elevation data comparison tool, leading CNES to collaborate with the GlacioHack collective and join the governance of their open-source software xDEM. Originally developed for glacier research, xDEM offered valuable features for 3D data analysis, including 3D coregistration and uncertainty analysis. Recognizing its potential, CNES strategically chose to contribute to xDEM rather than maintain its own tool, demcompare. The main contributions include improvements in scalability, visualization, and ease of use. This collaboration has created a more robust tool that benefits both the CO3D mission and the broader scientific community. By combining resources and expertise, the project demonstrates how open-source development can drive innovation while reducing duplication of effort.