gait analysis

A computer programme has been developed to process the image of a shadow cast on the ground, and match it up with its owner.
The technique, called gait analysis, works on the premise that it is extremely difficult to disguise your walking style.
It could be used to monitor known criminals and suspected terrorists, such as Osama Bin Laden, using satellites or spy planes.
There has been an explosion in satellite imagery and technology in recent years, but it is still virtually impossible to recognise people from pictures taken from orbit. Images from high-altitude aircraft and spacecraft only ever the tops of their heads.
Aerial shots alone give little away about a person's movements, but analysing the shadows they cast can - provided their walking pattern is on file.
According to Dr Adrian Stoica of Nasa's Jet Propulsion Laboratory in California, which developed the shadow technology, video from space could provide enough data to confirm a suspect's identity.