1. Colour remote sensing of the impact of artificial light at night (II): calibration of DSLR-based images from the International Space Station
- Author
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Sánchez de Miguel, Alejandro, Zamorano Calvo, Jaime, Aubé, Martin, Bennie, Jonathan, Gallego Maestro, Jesús, Ocaña González, Francisco, Pettit, Donald R., Stefanov, William L., Gaston, Kevin J., Sánchez de Miguel, Alejandro, Zamorano Calvo, Jaime, Aubé, Martin, Bennie, Jonathan, Gallego Maestro, Jesús, Ocaña González, Francisco, Pettit, Donald R., Stefanov, William L., and Gaston, Kevin J.
- Abstract
© 2021 The Author(s). We thank R. Moore of the Image Science and Analysis Group, NASA Johnson Space Center for information on ISS cameras and window properties. We thank Lucía García for her help with improving some figures. We also thank the anonymous reviewers for their constructive feedback. This work was supported by the EMISSI@N project (NERC grant NE/P01156X/1), Fonds de Recherche du Québec: Nature et Technologies (FRQNT), COST (European Cooperation in Science and Technology) Action ES1204 LoNNe (Loss of the Night Network), the ORISON project (H2020-INFRASUPP-2015-2), the Cities at Night project, FPU grant from the Ministerio de Ciencia y Tecnologia and F. Sánchez de Miguel. Cameras were tested at Laboratorio de Investigación Científica Avanzada (LICA), a facility of UCM-UPM funded by the Spanish program of International Campus of Excellence Moncloa (CEI). We acknowledge the support of the Spanish Network for Light Pollution Studies (MINECO AYA2011-15808-E) and also from STARS4ALL, a project funded by the European Union H2020-ICT-2015-688135. This work has been partially funded by the Spanish MICINN, (AyA2018-RTI-096188-B-I00), and by the Madrid Regional Government through the TEC2SPACE-CM Project (P2018/NMT-4291), Miniesterio de Ciencia y Tecnología (H2020). The ISS images are courtesy of the Earth Science and Remote Sensing Unit, NASA Johnson Space Center. Thanks to S. Doran for helping us to locate the missing image that we use as an example. We are very grateful to all members of the crews of the ISS from all agencies, NASA, ESA, JAXA, CSA-ASC and ROSCOSMOS, for their images., Nighttime images taken with DSLR cameras from the International Space Station (ISS) can provide valuable information on the spatial and temporal variation of artificial nighttime lighting on Earth. In particular, this is the only source of historical and current visible multispectral data across the world (DMSP/OLS and SNPP/VIIRS- DNB data are panchromatic and multispectral in the infrared but not at visible wavelengths). The ISS images require substantial processing and proper calibration to exploit intensities and ratios from the RGB channels. Here we describe the different calibration steps, addressing in turn Decodification, Linearity correction (ISO dependent), Flat field/Vignetting, Spectral characterization of the channels, Astrometric calibration/georeferencing, Photometric calibration (stars)/Radiometric correction (settings correction - by exposure time, ISO, lens transmittance, etc) and Transmittance correction (window transmittance, atmospheric correction). We provide an example of the application of this processing method to an image of Spain., Unión Europea. Horizonte 2020, Ministerio de Ciencia e Innovación (MICINN), Ministerio de Economía y Competitividad (MINECO), Comunidad de Madrid, UK Research & Innovation (UKRI), Natural Environment Research Council (NERC), Fonds de Recherche du Quebec: Nature et Technologies (FRQNT), European Cooperation in Science and Technology (COST), Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub
- Published
- 2021