ISO 19923:2017 specifies space plasma environments that lead to the generation of the worst-case surface potential differences for spacecraft. It also specifies how to estimate worst-case potential differences by using the simulation codes provided.
ISO 19923:2017 includes plasma energy and density in GEO, PEO, and MEO. ISO 19923:2017 does not include descriptions of plasma energy and density in LEO because large surface charging in LEO is likely to be due to high-voltage power generation by instrumentation of the spacecraft.
ISO 19923:2017 deals with external surface charging of spacecraft only.