Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Heterogeneous Aerial Reconnaissance Team -- formerly known as the "Heterogeneous Urban RSTA Team" -- program was an aerial surveillance project funded by the Information Processing Technology Office of the Defense Advanced Research Projects Agency. The purpose of the program was to develop systems that could provide continuous, real-time, three-dimensional surveillance of large urbanized areas, using unmanned aerial vehicles. The project team was led by Northrop Grumman corporation, and involved several other academic and corporate researchers. The unique features of the HART program are that it developed systems to "decouple soldiers from flight control" -- that is, the UAVs automatically pilot themselves taking care of flight control, collision prevention, and camera/sensor control automatically. When the drones notice suspicious activity, they notify the person with the HART control panel so that they can monitor the situation. Another feature of HART was to design handheld devices, to display surveillance video to small unit leaders in the field.