Fostering a community-driven and sustainable HELIOS++ scientific software

• Applicants: Professor Dr. Bernhard Höfle; Dr. Dominic Kempf
• Subject Area: Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 528521476

Laser scanning is a leading method to capture the environment and its dynamics in 3D space and time and it is widely used in geosciences and environmental sciences. The open-source scientific software HELIOS++ is a general-purpose framework to perform realistic – but virtual – laser scanning acquisitions in a computer simulation to create synthetic LiDAR data. Such virtual laser scanning enables full control of acquisition parameters and reproducibility in the data creation process, as well as highly automatic workflows coupled with data analysis. Major strengths of HELIOS++ are 1) that it can simulate over a large range of spatial scales and combination of scales and geometric detail in one simulation and 2) that it supports a multitude and extendable number of different platforms and scanners, which are easily inter- and exchangeable. Due to is modularity, HELIOS++ is a growing project and it has been cited and used in many publications. Main application cases of HELIOS++ are i) the improvement of acquisition planning, ii) algorithm development, iii) generation of training data for machine learning and particularly deep learning, iv) design of novel future sensors, and v) use as an education platform. The aims of this project are threefold: First, to increase usability and impact by a) improved interoperability with leading third-party software, b) a web-enabled HELIOS++ data management including DOI archiving of full surveys, c) a high-level Python API and Jupyter integration, d) a novel tool for scientific usability checks to validate individual fitness-for-purpose of HELIOS++. Second, we will increase quality assurance by a) refactoring the C++ core, b) implementing professional code governance standards (e.g. code review, coverage reports) and c) offering modern packing and continuous delivery (e.g. Conda). Third, further sustainable development will be fostered by increasing the user and developer base by direct active community building for users (e.g. online teaching materials and workshops) and developers (e.g. professional onboarding for developers) as well as several indirect effects such as more potential users/developers through the Pythonic API. One main strength of this interdisciplinary project is the tight and strategic long-term integration of an internationally recognized and increasingly used scientific software for laser scanning simulation into an institutional Scientific Software Center (SSC) at Heidelberg University. This enables to co-design and to “co-source” a professional, sustainable and highly improved scientific method and software.

• DFG Programme: Research Grants