Students, staff, alumni and prospective students are cordially invited to join the Public Defense by MSc Graduate Stefan Bruhlmann who will defend this dissertation “Measuring and Mapping Light Pollution at a Local Scale”.
Date: Friday 20th February
Location: VU Main Building, room 11A-36
Measuring and Mapping Light Pollution at a Local Scale
The aim of this thesis is to explore the use of Geographical Information System (GIS) technology in measuring, modelling and visualizing light pollution at a local scale. Light pollution is a worldwide phenomenon that is increasingly topical because of its detriment effects. Existing light pollution maps predominantly use and visualize remotely sensed data. This study hypothesizes that the information content of such maps is limited at a local level. A modelled approach was therefore developed to fill this lack of information. A variety of users are expected to benefit from highly detailed light pollution maps. The research design included both, desk and field research. The most important light sources in a research area around the city of Winterthur (Switzerland) were identified. Light sources included particularly the different types of street lighting, but also the lighting of car parking or sports fields. Measurements for each light source were taken in the field by the use of a lux meter. The collected data determined the parameters for a GIS based model which allowed the production of a local light pollution map. In order to validate the modelled results, the map was compared with a DSLR night image taken from the International Space Station(ISS). A deviation map was established and analyzed.
Based on the results of this research, it could be confirmed that the use of satellite data to visualize light pollution at a local level is limited. A GIS model is however found to be a promising approach to produce detailed light pollution maps that feature a high accuracy at a regional and local level. The comparison of the modelled maps with the ISS image showed a significant consistency. Modelled maps have the advantage of being relatively cheap in their production and they facilitate the creation of scenarios. Various interest groups, municipalities and the individual citizen are supposed to find interest in light pollution data and maps at a local level.
Further research is nevertheless needed to enhance the model and to increase the significance of the presented light pollution maps.