NECSI plots tweets by sentiment, positive or negative. A cluster of negative tweets in Queens, New York, for example, led to the discovery of a leaky sewer pipe.
"In some places, satellite images can be 10 years old," says engineer Bobby Sudekum. "You can fly a drone and process images of something that happened just hours ago." Read more >>
Geotagged disaster relief
To make use of the vast amount of information placed on social media during natural disasters, volunteers sift through geotagged posts from affected areas, plotting them on maps for aid workers. Read more >>
[Illustration by Dan Matutina]