TY - JOUR
KW - Atmospheric optics
KW - Computation time
KW - Fast Fourier transform algorithm
KW - Fast Fourier transforms
KW - Fourier transform
KW - Fourier transforms
KW - Health risks
KW - Informed decision
KW - Light
KW - Light pollution
KW - Luminance
KW - Natural environments
KW - Optical astronomy
KW - Photometry
KW - Pixels
KW - Pollution control
KW - Radiometry
KW - Related functions
KW - Satellites
KW - Spatial resolution
KW - Light pollution
KW - mapping method
KW - nightglow
KW - optical property
KW - photometer
KW - radiometer
AU - Salvador Bara
AU - Fabio Falchi
AU - Riccardo Furgoni
AU - Raul Lima
AB - Light pollution poses a growing threat to optical astronomy, in addition to its detrimental impacts on the natural environment, the intangible heritage of humankind related to the contemplation of the starry sky and, potentially, on human health. The computation of maps showing the spatial distribution of several light pollution related functions (e.g. the anthropogenic zenithal night sky brightness, or the average brightness of the celestial hemisphere) is a key tool for light pollution monitoring and control, providing the scientific rationale for the adoption of informed decisions on public lighting and astronomical site preservation. The calculation of such maps from satellite radiance data for wide regions of the planet with sub-kilometric spatial resolution often implies a huge amount of basic pixel operations, requiring in many cases extremely large computation times. In this paper we show that, using adequate geographical projections, a wide set of light pollution map calculations can be reframed in terms of two-dimensional convolutions that can be easily evaluated using conventional fast Fourier-transform (FFT) algorithms, with typical computation times smaller than 10(-6) s per output pixel.
BT - Journal of Quantitative Spectroscopy and Radiative Transfer
DA - jan
DO - 10.1016/j.jqsrt.2019.106658
LA - English
N1 - Publisher: Elsevier Ltd
N2 - Light pollution poses a growing threat to optical astronomy, in addition to its detrimental impacts on the natural environment, the intangible heritage of humankind related to the contemplation of the starry sky and, potentially, on human health. The computation of maps showing the spatial distribution of several light pollution related functions (e.g. the anthropogenic zenithal night sky brightness, or the average brightness of the celestial hemisphere) is a key tool for light pollution monitoring and control, providing the scientific rationale for the adoption of informed decisions on public lighting and astronomical site preservation. The calculation of such maps from satellite radiance data for wide regions of the planet with sub-kilometric spatial resolution often implies a huge amount of basic pixel operations, requiring in many cases extremely large computation times. In this paper we show that, using adequate geographical projections, a wide set of light pollution map calculations can be reframed in terms of two-dimensional convolutions that can be easily evaluated using conventional fast Fourier-transform (FFT) algorithms, with typical computation times smaller than 10(-6) s per output pixel.
PY - 2020
T2 - Journal of Quantitative Spectroscopy and Radiative Transfer
TI - Fast Fourier-transform calculation of artificial night sky brightness maps
UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85073255076&doi=10.1016%2fj.jqsrt.2019.106658&partnerID=40&md5=eed0f071c0cca5b69aa3acaa2b2a83ea
VL - 240
SN - 00224073 (ISSN)
ER -