SP01: Quantification of light pollution
Investigation of the sources and extent of the urban light dome of Berlin, and their temporal variation
Subproject 01 is carried out at the Institute for Space Sciences at the FU Berlin (FUB ISS) and at the Leibniz Institute of Freshwater Ecology and Inland Fisherie (IGB). The subproject investigates the
light dome over Berlin, and its variations in time and space. This will be accomplished with both aerial and ground based measurements, in multiple spectral channels.
When light travels through the sky, it is occasionally scattered or absorbed by atmospheric components. In the daytime, scattering from molecules makes the sky blue and the sunset red, scattering from water droplets produces rainbows, and scattering and absorption from aerosols allow us to see smog. In the nighttime, these same scattering processes return some of the light emitted upward from cities back towards the ground, producing the "sky glow" present over large cities at night. In addition to blocking the view of faint stars and the milky way, this sky glow is believed to influence urban ecosystems, and may disturb the circadian rhythms of the humans and animals living in the city.
By continually monitoring the brightness of the sky from the ground, we will observe how the sky glow changes in response to the changing weather and seasons, and will begin to track how the sky brightness changes from year to year. Using aerial photography and spectrography, we will also map out the spacial and spectral distributions and intensities of the sources of light on the ground. This map will make possible simulations of the sky glow of the city, will provide a dataset for testing algorithms for future satellite based missions.
We have composed a preliminary high resolution mosaic image of Berlin using about 3000 aerial photos taken at 10,000 ft on a clear night. Samples of the photos with reduced resolution are shown below.
Scientist is Dr. Christopher Kyba
Leader of subproject is Prof. Dr. Jürgen Fischer