There’s a 007 trove of gizmos behind the Olympics Games to help separate medal-winners from the also-rans.

The swimming competition is closely monitored by sensors –embedded inside the starting block– that record when a swimmer leaves, and by an ultrathin plastic touchpad on the wall under the water that calculates within hundredths of a second when the swimmer lands. Cameras that take 100 pictures a second, aimed on the touch pads and starting blocks, back up the touch system.

This year’s newest technology is the beach volleyball radar gun that clocks the speed of spikes and serves. Identical to those used in tennis, the devices rely on the Doppler effect to determine the speed of the ball. The displacement speed is calculated by comparing the ultrasonic frequencies picked up by the radar and the speed at which the echo is returned.

Marathon runners will have microchips tied to the laces of their shoes. Every five miles, the runners will pass by an antenna that records their distance and speed.

Bicyclists use a transponder clipped to a spoke on their front wheel to record their finish time. It sends signals from the bike to antennae along the route so judges can confirm who is in first.

The cameras used in track and field, which take 1,000 images per second, shoot only the first 8 millimeters of the finish line. As the runners cross, the cameras capture their bodies in a series of thousands of minuscule bits, first photographing the tip of the toe, then the finger, then the tip of the nose.

All those thousands of pictures are then electronically pieced together to reproduce a photo finish.

The same technology is used in rowing, flat water canoe and kayaking, and cycling events.

More details in SFGate.
Related entry: A tag on the running shoes.