Introduction ############ geonum is a python library written in Python 3 for geographic calculations. It provides intuitive objects for representing locations on Earth in terms of longitude, latitude and altitude, as well as associated arithmetics. geonum was developed together with the `pyplis `_ library (python plume imaging software) to provide the required tools to derive the required measurement geometry (e.g., distance of camera to volcanic emission plume, see e.g. `Gliss et al., 2017, Figure 3 therein `__). .. include:: _features.rst .. include:: _copyright.rst