Kuechly, HU et al. (2012): Mosaic image of the artificial light produced by Berlin on the night of September 11, 2010 observed from an altitude of 10,000 ft. doi:10.1594/PANGAEA.785492, Supplement to:Kuechly, Helga U; Kyba, Christopher C M; Ruhtz, Thomas; Lindemann, Carsten; Wolter, Christian; Fischer, Jürgen; Hölker, Franz (2012): Aerial survey and spatial analysis of sources of light pollution in Berlin, Germany. Remote Sensing of Environment, 126, 39-50, doi:10.1016/j.rse.2012.08.008
Aerial observations of light pollution can fill an important gap between ground based surveys and nighttime satellite data. Terrestrially bound surveys are labor intensive and are generally limited to a small spatial extent, and while existing satellite data cover the whole world, they are limited to coarse resolution. This paper describes the production of a high resolution (1 m) mosaic image of the city of Berlin, Germany at night. The dataset is spatially analyzed to identify themajor sources of light pollution in the city based on urban land use data. An area-independent 'brightness factor' is introduced that allows direct comparison of the light emission from differently sized land use classes, and the percentage area with values above average brightness is calculated for each class. Using this methodology, lighting associated with streets has been found to be the dominant source of zenith directed light pollution (31.6%), although other land use classes have much higher average brightness. These results are compared with other urban light pollution quantification studies. The minimum resolution required for an analysis of this type is found to be near 10 m. Future applications of high resolution datasets such as this one could include: studies of the efficacy of light pollution mitigation measures, improved light pollution simulations, economic and energy use, the relationship between artificial light and ecological parameters (e.g. circadian rhythm, fitness, mate selection, species distributions, migration barriers and seasonal behavior), or the management of nightscapes. To encourage further scientific inquiry, the mosaic data is freely available at Pangaea.
The data files are geotiff images with a resolution of 1 meter. Regions that were not imaged have a pixel value of 0. All imaged regions have an offset of +100 applied to guarantee that negative values do not occur (values less than 100 occur in areas that are unlit, due to CCD noise). Any quantitative analysis of the image will require removing this offset from each pixel. Horizontal striping is an artifact due to overly bright light incident on the storage elements of the interline transfer CCD. The image was acquired in 13 East-West tracks and one final North->South cross track. Imaging started at the South of the city at 20:40 local time (UTC+2) and proceeded northwards. The camera lost focus for a period during the western side of the third track. Imaging was completed at 23:23 local time. Complete details regarding the acquisition and processing are available in the related article.
The positioning uncertainty was found to be below 10 meters, although we know of a small number of regions where it is considerably worse due to unusually large course corrections by the pilot. The motion stabalizing platform was turned off when the aircraft needed to bank to turn around after each track, and therefore the positioning uncertainty is certain to be much larger at the edges of the tracks.
The archived data consists of three geotiffs and one image:
Berlin_detail_inner_city.zip contains a 9 MB geotiff called "detail_inner_city.tif". It is included so that users can download and test that they can view a small file before downloading the full mosaic.
Berlin_mosaic.zip contains the full 878 square km mosaic in a 3.1 GB geotiff called "mosaic.tif"
Berlin_study_area.zip contains the cutout of the full mosaic that was analyzed in the reference in a 1.5 GB geotiff called "study_area.tif"
Berlin_20m_res.jpg shows a representation of the study area at 20 meter resolution.
This work was supported by the Verlust der Nacht project (funded by the Federal Ministry of Education and Research, Germany, BMBF-033L038A) and by focal area MILIEU (FU Berlin).