Where’s Waldo . . . and 6 billion others?

Scientists at Oak Ridge (Tenn.) National Laboratory have combined satellite imagery and detailed census data to develop a worldwide database that can provide estimates of the number of people located in areas on a grid that has boxes with areas of 1 square kilometer or less.

The researchers describe the LandScan database, which they say will help determine populations at risk from natural and manmade disasters, in the July Photogrammetric Engineering & Remote Sensing.