Thermal imager has the edge on cricket umpires

12 Dec 2006

A thermal imaging camera originally developed to track missiles looks to be just as useful at making tricky decisions on the cricket field.

A thermal imaging camera based on indium antinomide chips could be used to decide whether or not batsmen playing cricket should be given "out".

How's that?

When a bowler fires a cricket ball into a batsman’s bat or protective pads at speeds of up to 100 mph, the split-second collision produces friction, and therefore a brief blast of low-level heat.

The mid-infrared light emitted can be picked up by a highly sensitive camera that was originally developed for defense applications by the French company CEDIP.

CEDIP’s Emerald IR cameras, which are being used by the Nine Network to cover the current "Ashes" series of cricket matches between Australia and England, are built around a focal plane array sensor based on InSb chips.

The 640x512 pixel arrays detect in the 3-5 µm wavelength region, and the InSb chips are sourced from an external supplier.

So far, two of CEDIP’s cameras have been showcased by Channel Nine to general acclaim in matches won by Australia at Brisbane and Adelaide. Although the technology is not yet being used by the umpires that adjudicate the game, it can easily tell whether or not a ball has flicked the edge of a player’s bat – and therefore whether or not he should be given out if the ball is caught by a opposition fielder, or adjudged to be "leg-before-wicket".

"It's the best technology I've seen," former England captain and Channel Nine commentator Tony Greig told Australia’s Herald Sun newspaper. "Now there is something that can tell you if there’s an edge or not."

If the CEDIP cameras had been used in the Adelaide match, they may have helped England to avoid an embarrassing batting collapse and subsequent defeat.

England opening bat Andrew Strauss appeared to miss a ball bowled by Aussie legend Shane Warne that bounced off Strauss’s pads and lobbed into the hands of fielder Mike Hussey.

Had the "Hot Spot" camera been employed by the cricket authorities, it would have shown that the ball did not hit the player's bat and Strauss would likely have been judged "not out".

The International Cricket Council has previously decided to aid umpires by allowing the use of television replays to decide on close decisions. Whether or not CEDIP's high-technology approach is sanctioned by the game's establishment for subsequent series of international cricket matches remains to be seen.