Hot Spot is an

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of Light, visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from ...

imaging system used in

cricket Cricket is a bat-and-ball game played between two teams of eleven players on a field at the centre of which is a pitch with a wicket at each end, each comprising two bails balanced on three stumps. The batting side scores runs by st ...

to determine whether the ball has struck the batsman, bat or pad. Hot Spot requires two

cameras on opposite sides of the ground above the field of play that are continuously recording an image. Any suspected nick or bat/pad event can be verified by examining the infrared image, which usually shows a bright spot where contact friction from the ball has elevated the local temperature. Where referrals to an off-field

third umpire The third umpire (or TV Umpire) is an off- field umpire used in some cricket matches, particularly international matches. Their role is to make the final decision in questions referred to them by the two on-field umpires or the players. The thir ...

are permitted, the technology is used to enhance the on-field umpire's decision-making accuracy. Where referrals are not permitted, the technology is used primarily as an analytical aid for television coverage.

Use

The system's principal application in

is in deciding whether the ball has struck the

batsman In cricket, batting is the act or skill of hitting the cricket ball, ball with a cricket bat, bat to score runs (cricket), runs and prevent the dismissal (cricket), loss of one's wicket. Any player who is currently batting is, since Septembe ...

's bat or pad – this determination being critical in determining if a

out Out may refer to: Arts, entertainment, and media Films * ''Out'' (1957 film), a documentary short about the Hungarian Revolution of 1956 * ''Out'' (1982 film), an American film directed by Eli Hollander * ''Out'' (2002 film), a Japanese film ba ...

or not on

appeal In law, an appeal is the process in which cases are reviewed by a higher authority, where parties request a formal change to an official decision. Appeals function both as a process for error correction as well as a process of clarifying and ...

for LBW or

caught Caught is a method of dismissing a batsman in cricket. A batsman is out caught if the batsman hits the ball, from a legitimate delivery, with the bat, and the ball is caught by the bowler or a fielder before it hits the ground. If the ball h ...

. In considering whether a batsman is out when the ball strikes bat then caught by a member of the fielding team or caught in front of the stumps when ball hits pad, one of the most difficult decisions is whether the ball struck the pad only, or the bat only, or (if it struck both) whether the pad or the bat was struck first. If the ball strikes the bat only, or strikes the bat followed by the pad, then the batsman could be

but not LBW. If the ball strikes the pad in front of the stumps or inline with stumps, then the batsman could be out LBW but not caught. If the ball strikes the pad followed by the bat, then the batsman could be

LBW or

if a fielder catches the ball. The batsman's bat and pad are often close together, and it can be very hard to determine by eye which was struck first, whereas the hotspot technology can often resolve the question. Hot-spot imagery is also used to show which part of the cricket bat hit the ball, as ideally the batsmen try to "middle" the ball i.e. hit it where the sweet spot lies. Hot spot camera provides some valuable information while analysing the strokes played by a batsman.

Mechanism

Hot Spot uses two infra-red cameras positioned at either end of the ground. These cameras sense and measure heat from

friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of ...

generated by a collision, such as ball on pad, ball on bat, ball on ground or ball on glove. Using a subtraction technique a series of black-and-white negative frames are generated into a computer, precisely localising the ball's point of contact.

History

Hot Spot uses technology developed in the military for tank and jet fighter tracking. The technology was adapted for television by BBG Sports, the Australian company responsible for the Snickometer. The technology was first used during the first Test match of the 2006-07 Ashes at

the Gabba The Brisbane Cricket Ground, commonly known as the Gabba, is a major sports stadium in Brisbane, the capital of Queensland, Australia. The nickname Gabba derives from the suburb of Woolloongabba, in which it is located. Over the years, the Ga ...

on 23 November 2006. The

International Cricket Council The International Cricket Council (ICC) is the world governing body of cricket. Headquartered in Dubai, United Arab Emirates, its members are 108 national associations, with 12 Full Members and 96 Associate Members. Founded in 1909 as the '' ...

announced that Hot Spot images would be available for use as part of its ongoing technology trial during the second and third Tests (March 2009) in South Africa. The system was to be available to the third umpire in the event of a player referral. For the 2012 season BBG Sport introduced a new generation of Hot Spot using high performance SLX-Hawk thermal imaging cameras provided by UK-based

Selex ES Selex ES was a subsidiary of Finmeccanica S.p.A., active in the electronics and information technology business, based in Italy and the United Kingdom, UK, and formed in January 2013, following Finmeccanica's decision to combine its existing SE ...

(part of Italian-owned defence contractor Finmeccanica, later renamed

Leonardo S.p.A. Leonardo S.p.A., formerly Leonardo-Finmeccanica and originally Finmeccanica, is an Italian multinational company specialising in aerospace, defence and security. Headquartered in Rome, Italy, the company has 180 sites worldwide. It is the eighth ...

). These cameras provided sharper images with improved sensitivity and much less motion blur than earlier Hot Spot technologies. As a result, the upgraded Hot Spot system was able to detect much finer edge nicks than in previous seasons, essentially ending all earlier doubts about the capability of the technology. Following the success of this updated Hot Spot system, BBG Sport and Selex signed an exclusivity agreement for the supply of SLX-Hawk cameras for Hot Spot in cricket and other sports.

Comparison

Hot Spot has two main advantages over its competing technology, the Snickometer and Ultra Edge, which are sound-detection based systems. These two systems often produce inconclusive results indicating contact (potentially any combination of bat, pad, feet shuffling, bat handle squeak) only, whereas the Hot Spot clearly shows exactly what that ball has struck. Independent testing has shown Snickometer and other competing sound based technologies are susceptible to the concept of the "Phantom Snick", where the sound of the ball whooshing past the bat sometimes creates a sound, even when the ball does not touch the bat.

References

{{DEFAULTSORT:Hot Spot (Cricket) Cricket equipment Cricket terminology Sports officiating technology