The technology of surveillance

With millions of CCTV cameras and one of the largest DNA databases in the world, the UK is among the most watched places in the world.
But how does the technology work?
Below is a guide which explains how some of the main types of surveillance operate.

Unmanned surveillance drones were first used by the police in 2008.
Unmanned aerial vehicle
The drones are lightweight weighing around 1.5kg, relatively quiet being battery powered, can carry different cameras and are remote controlled.

They can fly or hover while transmitting live images to an operator on the ground and can operate during the day or at night.
Unmanned aerial vehicles or UAVs can be used for many different activities such as searching for firearms or missing persons, road traffic accidents and surveillance after a terrorist attack.

The police are already using drones for aerial surveillance in Merseyside, Essex and Staffordshire.