Surveillance Camera withstands Tornado, Gives Important Data

In frames from the actual surveillance video produced by the KT&C camera inside the probe, Tim Samaras can be seen in silhouette estimating probe placement before the tornado passes over.
PHOTO COPYRIGHT Â© TIM SAMARAS

Looking like it crash-landed from the merry old land of Oz, a series of seven surveillance video cameras inside a bright orange steel probe shaped like a flattened space capsule, withstood a tornado to deliver the first-ever video at ground level â€“ just 10 feet from the tornadoâ€™s eye.

The dramatic video was taken by Tim Samaras, senior engineer at Applied Research Associates, Littleton, Colo. It was broadcast on television stations nationwide and reproduced with an article in National Geographic magazine. Samaras chases tornados for months during the summer and designed the probe.

The seven cameras inside the probe were the KPC 650 CH high-resolution color analog cameras from KT&C USA, the Korean manufacturer with U.S. headquarters in Los Angeles. According to Steve Je, KT&C marketing director, â€œThe whole body is not one solid part, but it is strong enough to survive the main purpose.â€

Added Samaras, â€œI selected the camera because of its small size, sensitivity, high resolution and incredibly fast shutter speeds under bright conditions of 1/64,000 of a second in bright daylight,â€ Samaras noted. â€œThis was an important factor in capturing the debris moving along at 50-80 meters per second, which is over 100 miles per hour.â€

Freezing the debrisâ€™ movement was crucial to using a technique called photogrammetry to calculate the wind speeds at ground level inside the tornado. â€œYou can see the veins of leaves as they fly past,â€ he pointed out.

Samaras measured the distance a stick of debris traveled during the 16.6 milliseconds between its two appearances in successive video frames of the same camera to estimate the wind speed.

The unique shape of the probe prevented it from being lifted into the tornado that passed over it.
PHOTO COURTESY OF KT&C

The probe, which is made of one-quarter-inch steel, has seven mini-DV recorders on the bottom of it underneath the cameras, which peer through windows of half-inch Lexan. One camera points directly up.

The entire probe weighs 85 pounds and is hermetically sealed and waterproof. A single switch turns on all the cameras and hard drives.

The KPC 650 CH high-resolution color analog camera from KT&C, Los Angeles, was selected for its size and fast shutter speed. PHOTO COURTESY OF KT&C

Unlike most debris in a tornado, the probes remained on the ground despite the high winds. Their squashed shape is key to their ability to stay put.

For more information, visit www.thunderchase.com. For information about KT&Câ€™s products, visit www.ktncusa.com or call (888) 767-CCTV.