Hut one, hut two...animate!

Middletown, RI -The marriage of technology and professional sports hasn't always been a happy one. Remember the glowing hockey puck that changed colors during a slap shot?

Now a Rhode Island company is helping to create another innovation-the glowing yellow line to mark the first-down chains in football games.

The strange line appears to have been painted, not projected, onto the field-since it does not overlap players' bodies as they pass over it-thus sparking countless barroom discussions of "How do they do that?"

The answer is FOG-that's a Fiber Optic Gyro-from KVH Industries. Sportvision Inc. (New York, NY), the company that created the 1st & Ten(TM)system, chose FOG sensors to counteract the effect of camera vibrations caused by wind or photographers. During a game, the sensors monitor camera wiggles 100 times per second and feed the information to a computer, which calculates how to make the line appear stationary.

There are actually three FOGs on each camera-one for each axis of motion-says Jim Dodez, VP at KVH. They work by measuring the angular rotation around an axis perpendicular to a coil of optical fiber, so they have no cross-axis sensitivity. Each has accuracy of plus or minus 0.002 degree, which is good enough to make the line look steady on television even when KVH testers are dropping a camera's tripod legs from six inches, Dodez says.