Towards future challenges in the measurement and modelling of night sky brightness

In ground-based astronomy, the brightness of the night sky is the limiting factor that determines the efficacy of any particular telescope in terms of detecting faint objects. Proper measurement and monitoring of night sky brightness (NSB) is therefore key to protecting sites of astronomical observatories from light pollution and maximizing their scientific productivity. However, current data sources and modelling approaches exhibit practical shortcomings that significantly limit their utility. By considering the current situation in measuring light pollution, we identify opportunities for improvements. These include defaulting to spatially resolved sky brightness measurements, routinely incorporating spectral information and polarization, and collecting simultaneous meteorological data. Given the acute threat to astronomy posed by rapidly increasing NSB around the world, we argue that the time has come for the standardization of NSB measurement and monitoring methods and protocols.