Promising new approach enables efficient, automatic mapping of urban areas from night lights
From far above the Earth, a satellite's view of nighttime lights reveals the globe's most populous urban areas. A new method maps urban areas using the night sky light intensity measured by those satellites; the method was developed by researchers at Pacific Northwest National Laboratory working at the Joint Global Change Research Institute. They collaborated with scientists from the National Oceanic and Atmospheric Administration (NOAA) and The Ohio State University (OSU) to reduce the over- and under-estimations associated with previous techniques when mapping a large area. The new method also shows the potential to map the extent of urban areas with a global perspective, and the changes over time, using existing data in a cost-efficient way.