RT Journal Article
T1 Estimating linear radiance indicators from the zenith night-sky brightness: on the Posch ratio for natural and light-polluted skies
A1 Bará Viñas, Salvador
A1 Pérez Couto, Javier
A1 Falchi, Fabio
A1 Kocifaj, Miroslav
A1 Masana, Eduard
K1 Scattering
K1 Atmospheric effects
K1 Light pollution
K1 Methods: numerical
AB Estimating the horizontal irradiance from measurements of the zenith night-sky radiance is a useful operation for basic and applied studies in observatory site assessment, atmospheric optics, and environmental sciences. The ratio between these two quantities, also known as the Posch ratio, has previously been studied for some canonical cases and reported for a few observational sites. In this work we (a) generalize the Posch ratio concept, extending it to any pair of radiance-related linear indicators, (b) describe its main algebraic properties, and (c) provide analytical expressions and numerical evaluations for its three basic night-time components (moonlight, starlight and other astrophysical light sources, and artificial light). We show that the horizontal irradiance (or any other linear radiance indicator) is generally correlated with the zenith radiance, enabling its estimation from zenith measurements if some a priori information on the atmospheric state is available
PB Oxford University Press
SN 0035-8711
YR 2022
FD 2022
LK http://hdl.handle.net/10347/29783
UL http://hdl.handle.net/10347/29783
LA eng
NO Salvador Bará, Xabier Pérez-Couto, Fabio Falchi, Miroslav Kocifaj, Eduard Masana, Estimating linear radiance indicators from the zenith night-sky brightness: on the Posch ratio for natural and light-polluted skies, Monthly Notices of the Royal Astronomical Society, Volume 512, Issue 2, May 2022, Pages 2125–2134, https://doi.org/10.1093/mnras/stac410
NO This work was supported by Xunta de Galicia/FEDER, grant ED431B 2020/29 (SB). EM acknowledges partial funding by the Spanish MICIN/AEI/10.13039/501100011033 and by ‘ERDF A way of making Europe’ by the European Union through grant RTI2018-095076-B-C21, and the Institute of Cosmos Sciences University of Barcelona (ICCUB, Unidad de Excelencia ‘María de Maeztu’) through grant CEX2019-000918-M. MK acknowledges funding from the Slovak Research and Development Agency, contract No. APVV-18-0014
DS Minerva
RD 24 abr 2026