WO2000044450A1

WO2000044450A1 - Golf ball flight monitoring system

Info

Publication number: WO2000044450A1
Application number: PCT/US2000/002163
Authority: WO
Inventors: Keith Stivers; Allan Epstein; Steve R. Lamb
Original assignee: Orthopedic Systems Inc.
Priority date: 1999-01-29
Filing date: 2000-01-28
Publication date: 2000-08-03
Also published as: JP2002535102A; KR20020005580A; AU2862400A

Abstract

A golf flight path and swing monitoring apparatus includes a first and second spaced-apart and preferably linear arrays of photosensors. The sensors each detect and discriminate when and whether a golf club head is located over them. A computer running a software program is configured for calculating the swing path, club head speed and club head angle at impact with a ball based on the monitored light signals of the sensors. Multiple temporally successive images of the ball after impact are captured for comparison preferably using a computer processor. The golf ball has a stripe around its surface that is apparent within each image notwithstanding the rotated position of the ball. Linear and circumferential extrapolations are calculated by the computer, and then the initial backspin, sidespin and three-dimensional velocity of the golf ball are calculated based on the images of the ball and the stripe, taking into account the diameters of the images and the curvature and position of the stripe, and the extrapolations. The sensors are used to trigger the shuttering of the camera and flashlamps used to capture the images. An impact image can also be captured and the relative position of the club head to the ball at impact observed and evaluated. The energy transfer efficiency of the impact between the club head and ball may also be determined.

Description

IN THE UNITED STATES PATENT AND TRADEMARK OFFICE APPLICATION FOR PATENT

TITLE: Golf Ball Flight Monitoring System

ATTY DOCKET: OSI-2300

Background of the Invention

1. Field of the Invention

The invention relates to a method and system for monitoring the

flight of a golf ball after impact with a golf club head, and particularly to

computer-controlled estimation of golf ball flight, impact timing and

transfer efficiency characteristics.

2. Discussion of the Related Art

Golf swing and golf ball flight monitoring have been used as tools

for golf instruction and for testing golf equipment such as golf clubs and

golf balls for many years. Such details as club head angle and club speed

at impact with the ball, as well as club take-away and downswing path,

are known to be crucial in determining ultimately important ball flight

characteristics, such as distance, direction, backspin and ball flight

curvature after impact. However, a golf swing is simply too fast in real

time for clear human observation of its many subtle features. High speed cameras and/or other sensors have been used to sense

and record data about the golf swing and/or initial ball flight

characteristics. The data is often displayed for slow speed analysis of a

golfer's form during the swing by an instructor and/or the golfer him or

herself. The position of the golfer's shoulders, hips, legs and/or head, as

well as his or her arms and hands, throughout the golf swing have been

captured on high speed still, video and television cameras either in a

series of still frames or in videos or movies replayable in slow motion.

Some such techniques are described, e.g., at U.S. patents no.

4,71 3,686, 5, 1 1 ,410 and 5,210,603.

Besides capturing the data described above of the golfer's form, data of the path of the golf club head during the swing and initial

characteristics of the golf ball in flight after impact with the club head are

often used. These latter data are more often used for determining total

ball flight characteristics such as distance, direction and curvature, rather

than the golfer's form, and are arguably more relevant factors than form

for determining the performance and effectiveness of a golfer's swing.

Moreover, equipment such as the golf club and golf ball being used can

be tested using these latter data, whereas the golfer's form really doesn't

affect such performance of the golfer's equpiment. Computer processors

running software algorithms are often used for calculating or more of the

above-mentioned features or others of the complete ball flight from the

sensed and recorded data. A series of United States patents assigned to Acushnet Company,

makers of Titleist™ golf equipment show and describe various techniques

and equipment for testing and determining golf club and golf ball

performance using measured pre-impact and post-impact characteristics

of the golf club and golf ball. These patents include U.S. patents no.

4,063,259, 4, 1 36,387, 4, 1 58,853, and 5,471 ,383.

For example, a pair of light source-photodetector pairs are

positioned as described in the '259 patent at spaced-apart locations

alongside the plane of the golfer's swing. Light emitted by each light

source is received by its corresponding photodetector unless an object

breaks the line of the emitted light to the detector. As the golf club head

nears the golf ball in a test method according to the '259 patent, the club

head swings through the line of sight of a first detector to the emitted

light from its corresponding light source. When this happens a signal is

sent to a camera shutter to open. Just before the club head impacts the

golf ball, a second line of sight of a second detector and its corresponding

light source is broken. At this time, a second signal causes a xenon lamp

to flash such that the reflected light is captured by the camera whose

shutter was previously opened.

Next, a microphone captures the sound of impact of the golf club

head with the golf ball. This acoustic signal is amplified and used as a

trigger for a second xenon lamp to flash such that a post impact image of

the golf ball is captured by the camera as shutter remains open. The

same amplified acoustic signal is sent through a delay and is used as a trigger for a third xenon lamp to flash such that another image post-

impact image of the golf ball in flight is captured by the camera. Shortly

thereafter the shutter of the camera is closed, and a still frame having

three images is stored on a film.

The use of a microphone to detect an acoustic signal requires

setting up and maintaining of the microphone, as well as precise

positioning and calibration separate from the optical components of the

system. Also, the sound of impact of the particular golf ball and club at

the test station where the microphone is being used has to be

distinguished from other club-ball impacts going on in the vicinity of the

microphone as well as from other sounds emanating from and around the

test area. It is desired to have a golf ball flight monitoring system that

does not use an acoustic photoflash trigger, and instead preferably uses

all photosensitive equipment.

The film including the three temporally successive images of the

golf ball reveals some useful initial characteristics of the flight of the golf

ball. For example, the initial launch angle and velocity can be determined

from the center of gravity positions of the successive images of the golf

ball, and the known time duration between the capturing of the second

and third images on the film, respectively. A mark placed on the ball prior

to performing the test can be used, as described at the '259 patent, to

reveal the amount of backspin initially imparted to the ball by the club

head. This initial backspin is determined based on how much the mark is

observed to have rotated in the plane of the film from the first to the second and from the second to the third images of the ball captured on

the film.

The small single mark described and shown in the '259 patent may

not be visible if side spin causes the mark to rotate to the "dark" side of

the ball, i.e., away from the camera side of the swing path. It is also

difficult to distinguish the backspin from the sidespin imparted to the ball

using the small single mark.

Lynch et al. were not concerned with sidespin in their description in

the '259 patent because a mechanical golfer was used that presumably

did not impart any sidespin to the ball at impact. Also, the mechanical

golfer was presumed to hit the ball straight ahead with each test swing so

that the initial direction of the golf ball was not considered as a factor in

any of the tests described in the '259 patent. Moreover, it is understood

that the '259 patent is drawn to equipment testing and not to analyzing

swing characteristics of a golfer. Thus, such ball flight characteristics as

the amount of fade or draw (or hook or slice, as the case may be) that a

golfer is achieving due to the sidespin the golfer is imparting at impact, or

the initial direction of the ball struck by the golfer, are not addressed in

the '259 patent. It is desired to have a ball flight monitoring system and

method that does determine ball flight characteristics based in part on the

initial horizontal direction of the golf ball's flight and the initially imparted

sidespin on the ball, in addition to the initial vertical flight conditions and

backspin on the ball. Each of the '387, '853 and '383 patents describes the use of one

or more highly reflective marks on the golf ball for determining initial post-

impact spin characteristics of the golf ball. Using subsequent images of

the one or more spots, each of these patents sets forth some description

of how to determine the complete spin characteristics of the golf ball, and

not simply the backspin as discussed above with respect to the '259

patent. However, the one or more spots may again not be visible to the

camera if they are rotated to the dark side of the ball when the image is

captured on film.

The '387 and '853 patents disclose to position three cameras or

photosensors each at ninety degree spaced locations around the golfer for

detection of the mark or marks wherever they may turn around the golf

ball. The three photosensors cannot be combined to achieve a single

planar image of the initial flight of the ball and the data captured by the

three photosensors is processed according to a complex algorithm that

factors the rotationally spaced locations of the sensors. Also, the angular

spacings of the sensors has to be very accurate or the calculated spin

characteristics of the ball will be unreliable. It is desired to have a method

and system for determining the complete initial spin characteristics of the

golf ball without having to sense marks on the ball in more than a single

observation plane.

The '383 patent sets forth a method for determining the total spin

imparted to the golf ball using six highly reflective marks or spots on the

ball and capturing their relative motions at successive temporal points within a single film frame. Data of the relative positions of the six marks

as captured on the film is converted to data directly related to the total

spin on the ball using a complex algorithm as described in the '383

patent. However, any one or all of the marks could again be rotated

during a real golf swing to the dark side of the ball in which case the

calculations would fail because the input data would be incomplete.

Gobush et al. are again concerned in the '383 patent with

equipment testing, and not golf swing analysis, and thus the mechanical

golfer used in the tests described in the '383 patent never imparts an

amount of sidespin to the ball sufficient to cause any of the marks to

rotate to the dark side of the ball before all of the camera images are

captured. It is desired to have a system and techniques for determining total spin imparted to a golf ball notwithstanding the degree of sidespin

on the ball.

The field of golf swing analysis is also understood in the present

invention to be lacking systems and techniques that measure and/or

determine or calculate and utilize data of the golf club head prior to

impact with the ball in conjunction with initial flight characteristics. Such

pre-impact club head data is desired, e.g., for determining energy transfer

efficiency between the club and ball, whether any sidespin or horizontal

ball directional characteristics are imparted by club head angle or swing

path characteristics, and for obviating the need for acoustic sensing of

impact for triggering image capture. It is also recognized in the present

invention that such a desired system and techniques would be useful for golf swing analysis as well as for testing equipment, including such

testing for determining the unique equipment specifications of particular

golfers depending on their individual

swing characteristics.

It is therefore an object of the invention to provide a golf ball flight

and golf swing monitoring system and technique wherein pre-impact

swing plane direction and head angle characteristics of the take away and

downswing of the golf club are measured and analyzed.

It is a further object of the invention to have a system and

technique for determining the total initial spin imparted to a golf ball,

including backspin and sidespin, and also preferably the three-dimensional

initial flight direction of the golf ball after impact with a golf club using a

single frame including multiple temporally successive images.

It is also an object of the invention to have a golf ball flight and golf

swing monitoring system and technique that combines pre-impact swing

characteristics with initial flight conditions of the golf ball to determine

transfer efficiency characteristics.

It is another object of the invention to provide a system and

technique for monitoring and analyzing initial ball flight characteristics

using a trigger for precisely timing the capture of temporally successive

images. Summary of the Invention

In accord with the above objects, a first aspect of the invention

includes an apparatus for monitoring characteristics of a golf swing path

and/or club head angle. The apparatus includes first and second arrays of

photosensors. Each array includes multiple sensors arranged at an angle

to the swing path. Preferably, the sensors are arranged substantially

orthogonally to the swing path. The first and second arrays are spaced-

apart from each other substantially in a direction along the swing path.

The sensors each receive a light signal unless the club head is located

over the sensor wherein the club head blocks the light signal.

A processor running a software program is configured for

calculating the swing path and/or club head angle based on the monitored

light signals of the sensors of the first and second arrays operated during a golf swing. The club head speed may be calculated based on the time

between the blocking of light signals for sensors in the first and second

arrays. The swing path and/or club head angle may be calculated based

on which sensors of one or both arrays are blocked and on the timing

between the blocking of the sensors of at least one array.

In a second aspect of the invention, multiple temporally successive

images of a golf ball after impact with a golf club are captured for

comparison preferably using a computer processor. The golf ball has a

continuous and preferably linear or substantially linear marking on its

surface that at least halfway circumambulates the golf ball such that the

marking is apparent within each image. The backspin imparted to the golf ball by the impact with the golf club head is then calculable based on a

comparison of the positions of the markings between two or more of the

images. Preferably, a linear estimation of the markings at each image is

first calculated and the backspin calculated based on the angle between

the markings on the two or more images. The sidespin is preferably

calculated based on the curvature of at least one of the markings.

In a third aspect of the invention, a photosensor is positioned a

known distance before the impact position of the golf club with the ball.

When a light signal received by the photosensor is blocked by the golf

club, a trigger signal is sent to a lamp that flashes a predetemined time

after receiving the trigger signal for capturing an image of the ball after

impact by a camera detector. Preferably, two spaced-apart sensors are

positioned before the impact position and the timing between the

successive blocking of the two sensors is used to calculate the club

speed prior to impact. The timing of the flash of the lamp is determined

based on this timing between the successive blockings of the two sensors

such that the ball is optimally positioned within the viewing range of the

camera.

In a fourth aspect of the invention, multiple images of the golf ball

after impact with the golf club are captured by a camera preferably as

described above. The computer processor determines the diameter of

two or more images of the golf ball. Based on the diameters of the two

or more images, the processor determines the three-dimensional velocity

of the ball including the initial horizontal direction of the flight of the ball. Brief Description of the Drawings

Fig. 1 a schematically shows a perspective view of a ball flight

monitoring system including an impact zone analyzer arranged on a hitting

mat.

Fig. 1 b schematically shows preferred electrical connections for the

system of Fig. 1 a.

Fig. 1 c schematically shows an overhead view of the impact zone

analyzer of Fig. 1 a.

Fig. 2 shows a display view illustrating golf club take away and

downswing paths and club head angle determined based on data obtained

from sensors of the impact zone analyzer of Fig. 1 .

Fig. 3a shows a display view of multiple temporally successive

images of a golf ball having a marking utilizing principles of the present

invention.

Fig. 3b shows a display view of multiple temporally successive

images of the golf ball having the marking of Fig. 3a, and software

generated linear and circumferential extrapolations based on the images.

Fig. 4a shows an overhead view representing total golf ball flight

characteristics calculated based on the images and extrapolations shown

in Fig. 3b.

Fig. 4b shows a side view representing total golf ball flight

characteristics calculated based on the images and extrapolations shown in Fig. 3b. Detailed Description of the Preferred Embodiment

Fig. 1 a schematically shows a perspective view of a ball flight

monitoring system including an impact zone analyzer 2 arranged on a

hitting mat 4. The impact zone analyzer 2 is imbedded within the hitting

mat 4 such that the surface of the analyzer 2 is substantially coplanar

with that of the hitting mat 4. The analyzer 2 is connected with a

computer processor 6 such that data signals may be sent to the computer

6 from the analyzer 2. Although a direct connection 7 is shown between

the analyzer 2 and the computer 6, the analyzer 2 may be indirectly

connected to the computer 6 through ball flight capture device or system

22, described below.

The analyzer has a first row 8 and a second row 10 of sensors 1 2

located behind a golf ball 14 on a tee 1 6. Preferably, each row 8, 10 has

around twelve sensors 1 2. The sensors 1 2 are preferably photosensors

such as light sensitive diodes or CCDs. The golf ball 14, of course, does

not have to be located on the tee 1 6. The analyzer 2 is preferably

conventionally connected to the computer 6 such that data representing

the amount of light that each sensor 1 2 receives throughout the duration

of a test golf swing may be received by the computer 6 from electronic

circuitry (not shown). The circuitry may be internal to the analyzer 2 or

external to the analyzer 2 such as within the ball flight capture device 22

that is connected to the analyzer 2, or otherwise. Although not shown, preferably an overhead lighting arrangement illuminates the hitting mat

and especially the first and second rows 8 and 10 of sensors 12.

A directional arrow 1 8 and footprints 20 are merely shown in Fig.

1 a to give the reader perspective as to where a golfer would be standing

during a test swing and what direction the golf ball would generally be

heading after impact with a golf club head of a golf club being swung by

the golfer.

The ball flight capture device 22 is located in front of the ball 14 on

the tee 1 6 across from where the ball 14 will be located in the air a short

time after impact with the golf club head. The device 22 includes a

camera 24 and one or more flash lamps, and preferably three flash lamps shown in Fig. 1 a as a first flash lamp 26, a second flash lamp 28, and a

third flash lamp 30. The device 22 is connected to the computer 6 and

preferably to the analyzer 2, as shown. Each of the device 22 and the

analyzer 2 may be connected to the computer either directly or through

other connections such as from the ball capture device 22 through the

analyzer 2 to the computer 6, or vice-versa.

Fig. 1 b schematically shows preferred electrical connections

associated with the ball flight monitoring system 100 of the present

invention. The ball capture device 22 has a cable connection labeled

"CPA cable" 32 which extends to the analyzer 2 on the hitting mat 4.

Three cable connections to the computer 6 from the ball flight capture

device 22 are labeled "cable 1 " 36, "cable 2" 38 and "cable 3" 34. The

computer 6 runs a software program specifically designed for processing input data from cables 34, 36 and 38, and may be otherwise a

conventional personal computer 6 including typical peripheral components

as shown.

Fig. 1 c schematically shows an overhead view of the impact zone

analyzer 2 including the ball 14 on a tee 1 6 prior to impact with a golf

club head from the right and a first row 8 and a second row 10 of

sensors are also visible in Fig. 1 c. Each of the sensors 1 2, the circuitry of

the analyzer 2 and the software running on the computer 6 (Figs. 1 a-1 b)

are preferably configured for distinguishing between when a golf club

head is over the sensor 1 2 and when the golf club head is not over the sensor 1 2. This is done by detecting when the overhead light is shining

on the sensors 1 2 and when a shadow is over the sensors 12 due to the

presence of the club head. That is, when the golf club head is not over a

particular sensor 1 2, then light from the overhead source is shining directly onto the sensor 12 yielding, e.g., a positive detection of the light

by the particular sensor 1 2. When the golf club head is over a particular

sensor 1 2, then light from the overhead source is blocked from directly

shining onto the sensor 12 yielding, e.g., a negative detection of light

from the overhead source by the particular sensor 1 2, or the detection (by

not detecting the direct light) of the shadow.

The swing path of the golf club and the angle of the club head just

before impact can be monitored using the first and second rows 8, 10 of

sensors 1 2. That is, based on the temporal order and/or duration or

degree of blocking of the individual sensors 1 2 during a test golf swing, the take away and downswing paths and the club head angle can be

monitored and displayed for evaluation. For example, if the center portion

of the club head is sensed as going over the sensor 1 2c and then the

sensor 1 2a, the swing is monitored as being somewhat inside out and the

impact with the ball maybe somewhat off the toe of the club, whereas if

the center portion of the club head is sensed as going over the sensor

1 2d followed by sensor 1 2b, then the impact would be monitored as

being of the heel of the club. Also, if the sensor 1 2a were blocked before

the sensor 1 2b of the second row 10 during the downswing, then the

club head angle would be detected as being somewhat open at the

second row 10 of sensors 12, whereas if the sensor 12b were detected

as being blocked before the sensor 1 2a, then the club head angle would

be detected as being somewhat closed at the second row 10.

Advantageously, the particular head angle and particular swing path can

be determined as well, and not just the general features described in the

general terms used in the above examples. The flashlamps 26, 28 and 30

and the camera 24 shown in Fig. 1 a are included in the embodiment of

Fig. 1 d, and are discussed in detail below.

Fig. 1 d illustrates an alternative ball flight monitoring system to the

system including the analyzer 2 illustrated at Fig. 1 a. The alternative

system does not include the analyzer 2 of the system of Fig. 1 a, but does

include the computer 6 and the ball flight capture device 22 described

above. Preferably two club sensing devices 39a and 39b for determining

club head speed and for triggering or initiating a process leading to the triggering of the camera 24 and/or the flash lamps 26, 28 and 30 is

provided in this alternative embodiment.

The sensors 39a and 39b are configured to detect when the club

head crosses in front of them, such as by crossing the imaginary lines L1

and L2 shown in Fig. 1 d for illustrative purposes. The sensors 39a and

39b may be photo or motion sensitive or otherwise for detecting the

precise time when the club crosses the imaginary lines L1 and L2. At

least one of the sensors 39a or 39b is preferably used for triggering the

camera 24 and lamps 26, 28 and 30. The system used input from

sensors 39a and 39b in determining the club head speed by analyzing the

time difference between when the imaginary lines L1 and L2 are crossed by the club head. The club speed is in turn used to estimte the time until

the ball will pass into the image field of the cmera 24. Using this estimated time, the system will calculate when to shutter the camera 24

and to flash the lamps 26, 28 and 30 to capture images of the ball with

the camera. Alternatively, a default or average timing is used from the

receipt of the trigger signal by the computer 6 and/or ball flight capture

device 22 for shuttering and flashing.

In one methdo of use, the club speed may be determined during a

calibration swing and that same determined value used for subsequent

swings. Alternatively, a new club speed may be determined for each

swing. In a third alternative method, an average or default club speed

may be used for all test swings, in which case only one of the sensors

39a or 39b is used simply for triggering. The head angle and take away and downswing paths that are advantageously determined in the way

described above in accord with the system of Fig. 1 a are not so

determined in this alternative embodiment.

The alternative system illustrated at Fig. 1 d may be advantageously

used for golf swing evaluations at any arbitrary hitting position, such as at

a typical driving range hitting mat or a grassy or sandy area. Thus, a golf

ball 14 sitting on a real grassy or sandy lie, or on a tee 1 6, may be

impacted by a golf club and the resulting ball flight evaluated using the

system shown at Fig. 1 d. In addition, the system of Fig. 1 d is more

portable for moving around a practice area or golf course.

Fig. 2 shows a display view illustrating a golf club take away path

40, a downswing path 42 and a club head angle 44 determined based on

data obtained from the first and second rows 8, 10 of sensors 12 of a preferred impact zone analyzer 2 overlayed in the display, in accord with

using the system shown at Fig. 1 a in accord with the present invention.

The take away path 40 and downswing path 42 are preferably the paths

of the center of gravity of the club head as it goes back during the take

away portion, and comes through during the downswing portion,

respectively, of a test swing. The paths 40, 42 could also be the paths

40, 42 of another point on the club head other than the center of gravity

such as a point nearer the heel or toe of the club head. The paths 40, 42

are determined based on which ones and in what order and/or for what

duration the individual sensors 1 2 of the first and second rows 8 and 1 0 were blocked during the take away and downswing portions of the test

swing.

The head angle 44 illustrated in the display is that of the club head

at the second row 10 nearest the impact point with the ball 14. The

distance between the second row 10 and the ball 14 may be closer than

is represented by any of Figs. 1 a-1 c or 2, such that the head angle 44 at

the second row 1 0 very nearly represents the ultimately important head

angle 44 at impact. On that point, none of the distances in the figures of

this application are necessarily drawn to scale.

The software may estimate the head angle at impact from the head

angle at the second row and/or at the first row, and may use another

estimate for the rate of closing of the head from the second row to the

impact point to make the estimation. For example, although the head

appears to be slightly open at the second row 10 in Fig. 2, the head 44 is

likely somewhat less open at impact, depending on the skill level of the

golfer performing the test swing. In practice, the second row 10 of

sensors 1 2 is so close to the impact position that the head angle at the

second row 10 of sensors 1 2 is at least almost exactly the head angle at

impact.

Fig. 3a shows a display view of three temporally successive images

46, 48 and 50 of a golf ball 14 during flight after impact with a golf club

head, wherein each golf ball image 46, 48 and 50 shows an image on the

golf ball 1 4 of a marking 52a, 52b and 52c, respectively, in accord with

the present invention. Although three images 46, 48 and 50 are shown, two or more than three images may be captured and used for determining

initial flight conditions of the ball 14. The computer 6 determines

kinematic properties of the ball in flight based on these images by

photogrammetry. The image capture timing is determined based on the

club head speed determined by the analyzer 2, preferably from a

calibration swing.

The actual marking on the ball 1 4 is preferably, but not necessarily,

circumferentially drawn around the entire ball 14 such as to separate the

ball 14 into two hemispheres like a meridian and to form a closed loop.

The marking is more specifically preferably at least halfway

circumambulatory of the ball 14, but need not be closed around the entire ball 14. The marking is preferably long enough that it may be within the

camera view no matter what the rotational position of the ball is when its

image is cpatured.

More than one marking may be provided. The two or more

markings may be off center such that for each marking the two areas

separated by the marking are not equal. The degree of equality or

inequality of the two areas is however known in each case and

programmed into the software running on the computer 6 of the ball flight

monitor system of the present invention.

The three images of Fig. 3a are exemplary of those captured by the

camera 24 of the ball capture device 22 discussed above, each due to the

flashing of one of the lamps 26, 28 and 30. By comparing and

contrasting two of or preferably all three of the images 46, 48 and 50 using the software running on the computer 6 and the known timing

between the capturing of the images, initial ball flight characteristics such

as horizontal and vertical velocity, including speed and direction, and total

spin, including backspin and sidespin, can be determined. Analysis and

computation by the processor running the particular software routines

programmed into it in accord with the present invention can then reveal

the total ball flight characteristics such as total distance and flight

trajectory.

Fig. 3b shows a display view of the multiple temporally successive

images 46, 48 and 50 of the golf ball 1 6 including the marking images

52a, 52b and 52c as shown and described with respect to Fig. 3a. In

addition, Fig. 3b shows software generated linear extrapolations 54a, 54b

and 54c of the marking images 52a, 52b and 52c, respectively. Also,

Fig. 3b shows circumferential extrapolations 56a, 56b and 56c based on

the two-dimensional captured perimeters of the images 46, 48 and 50,

respectively, in accord with the present invention. A calibration routine is

preferably used that allows the computer to recognize the general shape

and size within predetermined ranges of the images 46, 48, 50 of the

ball 1 4 after the images 46, 48, 50 are captured.

The linear extrapolations 54a, 54b and 54c of the marking images

52a, 52b and 52c are performed by the computer 6 from the curved

marking images 52a, 52b and 52c illustrated at Figs. 3a-3b. This

curvature is caused at least in part by sidespin on the ball 14 and/or the

location of the ball 1 6 at the times each image was captured relative to the camera exposure aperture in the vertical plane of the field of view shown at Fig. 3b, and the fact that the surface of the actual ball 14 is

curved. The software takes into account each of these factors in making

the linear extrapolations 54a, 54b and 54c.

Once the linear extrapolations 54a-54c are calculated, then the

initial backspin on the ball is calculated by first comparing and contrasting

the linear extrapolations 54a-54c. Qualitatively speaking, the initial

backspin may be determined in accord with the present invention based

on angular differences between the linear extrapolations 54a-54c and

known time differences between the capturing of the images 46, 48 and 50.

The circumferential extrapolations 56a-56c allow the computer to

determine the diameter of each image 46, 48, 50. Although the actual

diameter of the ball 14 does not change, at least after the ball resumes its

spherical shape after being deformed at impact, each image diameter

depends on how near to the camera that the ball is when each image 46,

48, 50 is captured. For example, a larger image diameter means the ball

14 was closer to the camera when the image 46, 48 or 50 was captured.

By analyzing one or more, preferably at least two or all three, of these

image diameters, the computer 6 can advantageously calculate the

horizontal direction that the ball 14 is initially heading in.

The curvatures of the actual markings 52a-52c is also used

advantageously to determine the sidespin on the ball 14. The rotated

positions of the markings 52a-52c as well as the curvatures at those positions allows the computer 6 to precisely determine the sidespin.

Advantageously, based on the sidespin so determined, the trajectory of

the ball flight, especially as the ball curves from left to right, may be

determined with precision. Thus, the combination of the determinations

made by the computer 6 based on the images 46, 48, 50, including the

extrapolations 54a-54c and 56a-56c, and the position and curvature

determination of the marking images, allows the computer to factor the

initial backspin and sidespin and initial vertical and horizontal velocities of

the ball 14 into the calculation of the total ball flight characteristics.

Another feature may be added to the any of the above

embodiments. That is, an additional image may be captured by the

system. The additional image is captured at the impact timing of the club head with the ball. The additional image would include an image of the

ball as well as the club head, and particularly the relationship between the

position of the ball with the club head at the impact time.

The additional image may be one captured with the use of an

additional flashlamp, or one of the flashlamps described above for use

with one of the images captured during the ball flight may be used to

capture the impact image. In the latter case, one fewer images will be

captured of the ball 14 during flight. For the embodiments described

above using three images, the images of the ball 14 in flight would then

be two, and one skilled in the art would realize that two is enough to

determine initial ball flight conditions. The ball flight capture device 22 may be modified to capture this

additional image at the time of impact. The modification may be simply

to move the camera 24 so that the impact position is within the viewing

range of the camera 24. The viewing range may also be widened to

include the impact position. The impact timing is estimated preferably

using a club head speed calculated in a calibration swing or also may be

calculated during the swing at issue or using a default club head speed.

After the club head passes one or both of the rows 8, 10 or one or both

of the sensors 39a, 39b, the time until impact being known based on the

club head speed and distance remaining until impact, the first flash is

produced by one of the flashlamps 26, 28 or 30, preferably flashlamp 26,

at the time of the impact and the image captured.

Advantageously, the position of the club head with respect to the

ball and/or the surface of the ground at impact are captured for analysis.

It may be observed from the captured image at impact whether the club

head is "toe up", "toe down" or even at impact. It may also be observed

whether the ball is struck at the center or nearer the toe or heel of the

club head at impact. In addition, it may be observed how open or closed

the face of the club is at impact, and it may also be observed what the

loft of the club is at impact. It may also be observed whether the ball

was impacted "thin" or "fat" from the captured image of the impact.

Fig. 4a shows an overhead view representing total golf ball flight

characteristics calculated based on the images and extrapolations shown

and described above, particularly with respect to Fig. 3b. Three horizontal flight trajectories are shown in Fig. 4a that were calculated

from three different test swings. The hoπzontal axis is the "distance" in

yards and the vertical axis is the left to right distance.

As can be observed, the ball started out moving in a direction right

of straightaway along flight path A, but then "drew", or moved right to

left due to counterclockwise spin (using the perspective of Fig. 4a)

imparted to the ball at impact. The swing that was calculated by the

computer 6 based on initial flight conditions to produce flight path A, and

determined in accord with the present invention, caused the ball to land

about 250 yards out and only about 5 yards right of straight away. The

ball traveling along flight path B started out a little less right of straight

away than that for flight path A, had a similar draw, and landed about 5

yards to the left of the flight path A ball. The ball traveling along flight

path C started even less right of straight away than that for flight path B,

and a little more draw such that the ball was calculated to land about 1 5

yards left of straight away, again about 250 yards down the fairway.

Fig. 4b shows a side view representing total golf ball flight

characteristics calculated based on the images and extrapolations

described above, particularly with respect to Fig. 3b. The horizontal axis

again shows the distance down the fairway that the ball was calculated

to travel in the air. This time, the vertical axis shows the height of the

golf ball as it traveled along its flight path. Again, three paths D-F are

shown in Fig. 4b. The golf swing that was calculated by the computer 6 to cause the

ball to travel along flight path D was shown to rise to about 140 feet

before beginning its downward ascent to land about 250 yards down the

fairway. The flight paths E and F has a maximum calculated altitude for

the respective balls to be 100 and 70 yards, respectively, while each ball

was calculated to land around 250 yards down the fairway.

It is emphasized that the flight paths shown and described with

respect to Figs. 4a and 4b are only examples to show the kinds of

calculations and displays that the present invention can do. Again, the

total initial spin including backspin and side spin and the total initial

velocity including components is three dimensions are advantageously

determined and used to calculate the flight paths of Figs. 4a and 4b. The

aerodynamic lift caused by spin and aerodynamic drag may be used as

inputs to figure the total flight characteristics of the ball. Other factors

may be inputs for the computer to use in the calculations such as wind,

air density or altitude, various club and ball parameters such as club

speed and loft, ball cover hardness or durometer reading, ball core spin

density, relative impact positions of the club head with the ball, weather

conditions such as rain, etc. As noted, the relative impact positions and

club speed can be determined in accord with the present invention.

Another parameter that may be advantageously calculated in

accord with the present invention is the energy transfer efficiency of the

impact of the club head with the ball. That is, the club head speed and

initial velocity and spin of the ball may be determined in accord with the present invention. Thus, the efficiency can be calculated by subtracting

the energy that a ball would have if a perfectly elastic collision occurred

between the club head and ball, and the actual energy that the ball is

observed to have in the form of translational and rotational kinetic energy

minus work done against gravity to reach the image position or positions

used in the calculation. This efficiency determination can be

advantageously used in consideration of the quality of the equipment, i.e.,

the ball and club, that are used during the test swing.

Claims

What is claimed is:

1 . An apparatus for monitoring a swing path and/or a golf club head

angle at or near an impact location with a golf ball during a golf swing,

comprising:

a first array of sensors arranged at an angle to the plane of the golf

swing and proximate to the impact location;

a second array of sensors also arranged at an angle to the swing

plane and spaced apart from the first array behind the impact position

along the swing path; and

a processor for receiving signals indicative of a temporal profile of

which sensors the golf club head is over for the duration of the swing.

2. The apparatus of Claim 1 , wherein said array is substantially

orthogonal to said swing plane.

3. The apparatus of Claim 1 , the processor further for recreating the

swing path of the club head as the club head moved between the first

and second arrays during the swing based on said temporal profile.

4. The apparatus of any of Claims 2 or 3, wherein the swing path

includes the take away swing path as the club head moved from the first

array to the second array during the swing.

5. The apparatus of any of Claims 2 or 3, wherein the swing path

includes the downswing path as the club head moved from the second

array to the first array towards the impact location during the swing.

6. The apparatus of any of Claims 1 or 2, the processor further for

recreating the club head angle as the club head moved across the first

array toward the impact location based on said received signals.

7. An apparatus for monitoring a golf club head angle at or near an

impact location of the club head with a golf ball during a golf swing,

comprising:

an array of sensors arranged at an angle to the plane of the golf

swing; and a processor for receiving signals indicative of a temporal profile of

which sensors the golf club head is over for the duration of the swing.

8. The apparatus of Claim 7, wherein said array is substantially

orthogonal to said swing path.

9. The apparatus of any of Claims 7 or 8, wherein the array is located

proximate to the impact location.

10. The apparatus of any of Claims 7 or 8, the processor for recreating the club head angle as the club head was sensed over the array based on

said temporal profile.

1 1 . The apparatus of any of Claims 1 or 7, further comprising an image

capture device including a camera for capturing two or more images of

the golf ball after impact with the golf club head, the processor further

for determining one or more dynamic parameters of the golf ball based

on said two or more images and for calculating one or more flight

parameters of a total flight path of said golf ball based on said one or

more dynamic parameters.

12. The apparatus of Claim 1 1 , wherein said golf ball includes a

marking that is at least partially in view of the camera for any

rotational position of the golf ball.

1 3. The apparatus of Claim 1 2, wherein said marking is substantially a

straight line at least halfway circumambulatory of the surface of the

golf ball.

14. The apparatus of Claim 12, wherein said marking is a closed loop

around the surface of the golf ball.

1 5. The apparatus of Claim 1 3, wherein said marking separates

substantially equal hemispheres of the golf ball.

1 6. The apparatus of Claim 1 2, wherein said marking separates

substantially equal hemispheres of the golf ball.

1 7. The apparatus of Claim 1 2, wherein said processor calculates a

linear extrapolation of said marking for each of said images.

1 8. The apparatus of Claim 1 7, wherein said processor calculates

backspin on said ball based on a comparison of at least two of said

linear extrapolations.

1 9. The apparatus of Claim 1 8, wherein said processor calculates

sidespin on said ball based in part on curvatures of said marking on

said images.

20. The apparatus of Claim 17, wherein said processor calculates a

circumferential extrapolation of two or more of said images.

21 . The apparatus of Claim 12, wherein said processor calculates

sidespin on said ball based in part on curvatures of said marking on

said images.

22. The apparatus of Claim 21 , wherein said processor calculates a

circumferential extrapolation of two or more of said images.

23. The apparatus of Claim 22, wherein said processor calculates

three-dimensions of velocity based in part on a comparison of

diameters of two or more of said circumferential extrapolations.

24. The apparatus of Claim 23, wherein said processor calculates

sidespin based in part on curvatures of said marking on said images.

25. The apparatus of Claim 1 1 , wherein said one or more dynamic

parameters are selected from the group of dynamic parameters consisting of backspin, sidespin and three-dimensions of velocity.

26. The apparatus of Claim 1 1 , wherein said one or more dynamic

parameters are determined based on at least one of the diameters of

said images, the curvatures of the markings on said images, and linear

extrapolations of the markings on said images.

27. The apparatus of Claim 1 1 , wherein said one or more dynamic

parameters include at least one of three-dimensional velocity, sidespin,

and backspin.

28. The apparatus of Claim 1 1 , wherein said one or more parameters

include sidespin.

29. The apparatus of Claim 1 1 , wherein said one or more parameters

include three dimensions of velocity.

30. An apparatus for determining one or more dynamic parameters of a

golf ball after impact with a golf club head based on two or more

images of said golf ball captured after said impact and for calculating

one or more parameters of a total flight path of said golf ball based on

said one or more dynamic parameters, comprising:

an image capture device including a camera for capturing two or

more images of the golf ball after impact with the golf club head; and

a processor connected with said image capture device,

wherein said golf ball has a marking that is at least halfway

circumambulatory of the surface of said golf ball such that said marking is at least partially within the view of said camera for any rotational position

of said golf ball when said images are taken.

31 . The apparatus of Claim 30, wherein said marking is a closed loop

around the surface of the golf ball.

32. The apparatus of Claim 31 , wherein said marking separates

substantially equal hemispheres of the golf ball.

33. The apparatus of Claim 30, wherein said marking separates

substantially equal hemispheres of the golf ball.

34. The apparatus of Claim 30, wherein said processor calculates a

linear extrapolation of said marking for each of said images.

35. The apparatus of Claim 34, wherein said processor calculates

backspin on said ball based on a comparison of at least two of said

linear extrapolations.

36. The apparatus of Claim 35, wherein said processor calculates

sidespin on said ball based in part on curvatures of said marking on

said images.

37. The apparatus of Claim 30, wherein said processor calculates a

circumferential extrapolation of two or more of said images.

38. The apparatus of Claim 37, wherein said processor calculates

sidespin on said ball based in part on curvatures of said marking on

said images.

39. The apparatus of Claim 36, wherein said processor calculates a

circumferential extrapolation of two or more of said images.

40. The apparatus of Claim 39, wherein said processor calculates

three-dimensions of velocity based in part on a comparison of

diameters of two or more of said circumferential extrapolations.

41 . The apparatus of Claim 30, wherein said processor calculates

sidespin based in part on curvatures of said marking on said images.

42. The apparatus of Claim 30, wherein said one or more parameters

are selected from the group of parameters consisting of backspin,

sidespin and three-dimensions of velocity.

43. The apparatus of Claim 30, wherein said one or more dynamic

parameters are determined based on at least one of the diameters of

said images, the curvatures of the markings on said images, and linear

extrapolations of the markings on said images.

44. The apparatus of Claim 30, wherein said one or more dynamic

parameters include at least one of three-dimensional velocity, sidespin,

and backspin.

45. The apparatus of Claim 30, wherein said one or more parameters

include sidespin.

46. The apparatus of Claim 30, wherein said one or more parameters

include three dimensions of velocity.

47. An apparatus for determining one or more dynamic parameters of a

golf ball after impact with a golf club head based on two or more

images of said golf ball captured after said impact and for calculating

one or more parameters of a total flight path of said golf ball based on

said one or more dynamic parameters, comprising: an image capture device including a camera for capturing two or

more images of the golf ball after impact with the golf club head; and

a processor connected with said image capture device for

determining and comparing diameters of said two or more images and

calculating a horizontal velocity component based on said diameter

determination and comparison.

48. An apparatus for determining one or more dynamic parameters of a

golf ball after impact with a golf club head based on two or more

images of said golf ball captured after said impact and for calculating

one or more parameters of a total flight path of said golf ball based on

said one or more dynamic parameters, comprising:

a first and a second sensors spaced-apart along a golf swing path

for detecting a golf club head at two different points during a

downswing portion of a golf swing; an image capture device including a camera for capturing two or

more images of the golf ball after impact with the golf club head; and

a processor for receiving signals indicative of when the golf club is

detected by each of the two sensors and estimating when the golf ball

will be within a view of said camera for capturing said one or more

images.

49. An apparatus for determining one or more dynamic parameters of a

golf ball after impact with a golf club head based on two or more

images of said golf ball captured after said impact and for calculating

one or more parameters of a total flight path of said golf ball based on

said one or more dynamic parameters, comprising:

a first and a second sensors spaced-apart along a golf swing path

for detecting a golf club head at two different points during a

more images of the golf ball after impact with the golf club head; and

a processor for receiving signals indicative of when the golf club is

detected by each of the two sensors, calculating the speed of the club

head during the downswing, calculating the total energy of the golf

ball based on said two or more images and calculating the transfer

efficiency of the club head to the golf ball at impact based at least in

part on said club head speed and said total energy of said golf ball.

50. The apparatus of Claim 49, wherein said total energy includes total kinetic energy from three-dimensional translational speed and total

rotational energy from backspin and sidespin.

51 . The apparatus of Claim 50, wherein said total energy includes work

done against gravitational potential since the time of impact.

52. The apparatus of any of Claims 47-49, wherein said golf ball has a

marking that is at least halfway circumambulatory of the surface of said

golf ball such that said marking is at least partially within the view of said

camera for any rotational position of said golf ball when said images are taken.

53. The apparatus of Claim 52, wherein said marking is substantially a

straight line within the plane of the surface of the ball.

54. The apparatus of Claim 52, wherein sidespin on said golf ball is

determined based on curvatures of said marking in said images.

55. The apparatus of Claim 52, wherein said processor calculates linear

extrapolations of said markings in said images and determines

backspin based on a comparison of said linear extrapolations.

56. The apparatus of any of Claims 30 or 47-49, wherein said

apparatus also captures an image of said golf ball and said golf club at

impact such that the relative orientation of said club with respect to

said ball may be evaluated.

57. The apparatus of Claim 1 1 , wherein said apparatus also captures

an image of said golf ball and said golf club at impact such that the

relative orientation of said club with respect to said ball may be

evaluated.

58. An apparatus for determining one or more dynamic parameters of a

golf ball after impact with a golf club head based on two or more

images of said golf ball captured after said impact and for calculating

one or more parameters of a total flight path of said golf ball based on

said one or more dynamic parameters, comprising:

an image capture device including a camera for capturing two or

more images of the golf ball after impact with the golf club head; and

a processor connected with said image capture device,

wherein said golf ball has a marking that is at least halfway

circumambulatory of the surface of said golf ball such that said marking is

at least partially within the view of said camera for any rotational position

of said golf ball when said images are taken, and

wherein said processor determines one or more initial flight

conditions of said ball based on an automatic determination of relative characteristics of at least one of said marking and diameters of said

images.

59. The apparatus of Claim 58, wherein said marking is a closed loop

around the surface of the golf ball.

60. The apparatus of Claim 59, wherein said marking separates

substantially equal hemispheres of the golf ball.

61 . The apparatus of Claim 58, wherein said marking separates

substantially equal hemispheres of the golf ball.

62. The apparatus of Claim 58, wherein said processor calculates a

linear extrapolation of said marking for each of said images.

63. The apparatus of Claim 62, wherein said processor calculates

backspin on said ball based on a comparison of at least two of said

linear extrapolations.

64. The apparatus of Claim 63, wherein said processor calculates

sidespin on said ball based in part on curvatures of said marking on

said images.

65. The apparatus of Claim 58, wherein said processor calculates a

circumferential extrapolation of two or more of said images.

66. The apparatus of Claim 65, wherein said processor calculates

sidespin on said ball based in part on curvatures of said marking on

said images.

67. The apparatus of Claim 64, wherein said processor calculates a

circumferential extrapolation of two or more of said images.

68. The apparatus of Claim 67, wherein said processor calculates

three-dimensions of velocity based in part on a comparison of diameters of two or more of said circumferential extrapolations.

69. The apparatus of Claim 58, wherein said processor calculates

sidespin based in part on curvatures of said marking on said images.

70. The apparatus of Claim 58, wherein said one or more parameters

are selected from the group of parameters consisting of backspin,

sidespin and three-dimensions of velocity.

71 . The apparatus of Claim 58, wherein said one or more dynamic

parameters are determined based on at least one of the diameters of said images, the curvatures of the markings on said images, and linear

extrapolations of the markings on said images.

72. The apparatus of Claim 58, wherein said one or more dynamic

parameters include at least one of three-dimensional velocity, sidespin,

and backspin.

73. The apparatus of Claim 58, wherein said one or more parameters

include sidespin.

74. The apparatus of Claim 58, wherein said one or more parameters

include three dimensions of velocity.

75. The apparatus of Claim 58, wherein said characteristics include the

relative orientations of said markings on said images.

76. The apparatus of Claim 58, wherein said characteristics include the

relative sizes of the diameters of said images.

77. The apparatus of Claim 58, wherein said conditions include three-

dimensional velocity of said ball.

78. The apparatus of Claim 58, wherein said conditions include sidespin

of said ball. The apparatus of Claim 58, wherein said conditions include

backspin and sidespin of said ball.

AMENDED CLAIMS

[received by the International Bureau on 23 June 2000 (23.06.00) ; original claims 1 - 79 replaced by new claims 1 - 82 (19 pages)]

1 . An apparatus for monitoring a swing path and/or a golf club head angle at or near an impact location with a golf ball during a golf swing,

comprising: a first array of sensors arranged at an angle to the plane of the golf swing and proximate to the impact location; a second array of sensors also arranged at an angle to the swing plane and spaced apart from the first array behind the impact position along the swing path; an image capture device including a camera for capturing two or more images of the golf ball after impact with the golf club head; and a processor for receiving signals indicative of a temporal profile of which sensors the golf club head is over for the duration of the swing and for determining one or more dynamic parameters of the golf ball based on said two or more images and for calculating one or more flight parameters of a total flight path of said golf ball based on said one or more dynamic

parameters.

2. The apparatus of Claim 1 , wherein said first and second arrays include a plurality of sensors arranged substantially linearly and orthogonal to said

swing plane.

3. The apparatus of any of Claims 1 or 2, the processor further for

recreating the swing path of the club head as the club head moved between

the first and second arrays during the swing based on said temporal profile.

4. The apparatus of Claim 3, wherein the swing path includes the take

away swing path as the club head moved from the first array to the second

array during the swing and the downswing path as the club head moved

from the second array to the first array towards the impact location during

the swing.

5. The apparatus of any of Claims 1 or 2, the processor further for

recreating the club head angle as the club head moved across the first array

toward the impact location based on said received signals.

6. The apparatus of Claim 5, wherein the first array includes a back sensor

that is positioned just behind the substantially linearly arranged sensors in

the first array along the swing path for determining the club head angle.

7. An apparatus for monitoring a golf club head angle at or near an impact

location of the club head with a golf ball during a golf swing, comprising:

an array of sensors arranged at an angle to the plane of the golf

swing; an image capture device including a camera for capturing two or more

images of the golf ball after impact with the golf club head; and

a processor for receiving signals indicative of a temporal profile of

which sensors the golf club head is over for the duration of the swing and

for determining one or more dynamic parameters of the golf ball based on

said two or more images and for calculating one or more flight parameters

of a total flight path of said golf ball based on said one or more dynamic

parameters.

8. The apparatus of Claim 7, wherein said array includes a plurality of

sensors arranged substantially linearly and orthogonal to said swing path.

9. The apparatus of Claim 8, wherein said array further includes a back

sensor behind said plurality of substantially linearly arranged sensors.

10. The apparatus of any of Claims 7-9, the processor for recreating the

club head angle as the club head was sensed over the array based on said

temporal profile.

1 1 . The apparatus of any of Claims 1 or 7, wherein said golf ball includes

a marking that is at least partially in view of the camera for any rotational

position of the golf ball.

12. The apparatus of Claim 1 1 , wherein said marking is substantially a

straight line at least halfway circumambulatory of the surface of the golf

ball.

13. The apparatus of Claim 1 1 , wherein said marking is a closed loop

around the surface of the golf ball.

14. The apparatus of Claim 13, wherein said marking separates

substantially equal hemispheres of the golf ball.

15. The apparatus of Claim 12, wherein said marking separates

substantially equal hemispheres of the golf ball.

16. The apparatus of Claim 12, wherein said processor automatically finds

said marking and calculates a linear extrapolation of said marking for each

of said images.

17. The apparatus of Claim 1 6, wherein said processor calculates

backspin on said ball based on a comparison of at least two of said linear

extrapolations.

18. The apparatus of Claim 17, wherein said processor calculates sidespin

on said ball based at least in part on curvatures of said markings on said

images.

19. The apparatus of Claim 16, wherein said processor automatically finds

a perimeter of at least one image and calculates a circumferential

extrapolation of said image.

20. The apparatus of Claim 19, wherein said processor determines

diameters of said two or more images based on said circumferential

extrapolations and calculates a three-dimensional velocity of said ball

based in part on a comparison of said diameters.

21 . The apparatus of Claim 19, wherein said processor calculates a

diameter based on said circumferential extrapolation and calculates a

three dimensional velocity of said ball based in part on said diameter.

22. The apparatus of Claim 12, wherein said processor automatically finds

a perimeter of at least one image and calculates a circumferential

extrapolation of said image.

23. The apparatus of Claim 22, wherein said processor determines

diameters of said two or more images based on said circumferential

extrapolations and calculates a three-dimensional velocity of said ball

based in part on a comparison of said diameters.

24. The apparatus of Claim 22, wherein said processor calculates a

diameter based on said circumferential extrapolation and calculates a

three dimensional velocity of said ball based in part on said diameter.

25. The apparatus of Claim 12, wherein said processor calculates sidespin

on said ball based in part on curvatures of said marking on said images.

26. The apparatus of Claim 25, wherein said processor calculates a

circumferential extrapolation of two or more of said images.

27. The apparatus of Claim 26, wherein said processor calculates three-

dimensions of velocity based in part on a comparison of diameters of two

or more of said circumferential extrapolations.

28. The apparatus of Claim 27, wherein said processor calculates sidespin

based in part on curvatures of said marking on said images.

29. The apparatus of Claim 1 1 , wherein said one or more dynamic

parameters are selected from the group of dynamic parameters consisting

of backspin, sidespin and three-dimensional velocity.

30. The apparatus of Claim 12, wherein said one or more dynamic

parameters are determined based on a diameter calculated based on an

automatic circumferential extrapolation of at least one image, the

curvature of the marking on at least one image, and automatic linear

extrapolations of the markings on at least two images.

31. The apparatus of Claim 30, wherein said one or more dynamic

parameters include at least one of three-dimensional velocity, sidespin,

and backspin.

32. The apparatus of Claim 1 1 , wherein said one or more parameters

include sidespin.

33. The apparatus of Claim 1 1 , wherein said one or more parameters

include three dimensional velocity.

34. An apparatus for determining one or more dynamic parameters of a

golf ball after impact with a golf club head based on two or more images of said golf ball captured after said impact and for calculating one or

more parameters of a total flight path of said golf ball based on said one

or more dynamic parameters, comprising:

an image capture device including a camera for capturing two or more

images of the golf ball after impact with the golf club head; and

a processor connected with said image capture device,

wherein said golf ball has a marking that is at least halfway

circumambulatory of the surface of said golf ball such that said marking is at

least partially within the view of said camera for any rotational position of

said golf ball when said images are taken, and

wherein said processor determines one or more dynamic parameters of

said ball based on an automatic determination of at least one characteristic

of at least one of said marking, a three-dimensional position of one or more

of said images and a diameter of one or more of said images.

35. The apparatus of Claim 34, further comprising one or more sensors for

triggering the capturing of the images by the camera.

36. The apparatus of Claim 35, wherein the one or more sensors are one

or more photosensors that sense the club head as the club head moves

past the one or more sensors during a downswing prior to impact with

the ball.

37. The apparatus of any of Claims 34 or 35, wherein said marking is a

closed loop around the surface of the golf ball.

38. The apparatus of Claim 37, wherein said marking separates

substantially equal hemispheres of the golf ball.

39. The apparatus of any of Claims 34 or 35, wherein said marking

separates substantially equal hemispheres of the golf ball.

40. The apparatus of any of Claims 34 or 35, wherein said processor

automatically finds said marking and calculates a linear extrapolation of

said marking for each of said images.

41 . The apparatus of Claim 40, wherein said processor calculates

backspin on said ball based on a comparison of at least two of said linear

extrapolations.

42. The apparatus of Claim 41 , wherein said processor calculates sidespin

on said ball based at least in part on curvatures of said markings on said

images.

43. The apparatus of Claim 40, wherein said processor automatically finds

a perimeter of at least one image and calculates a circumferential

extrapolation of said image.

44. The apparatus of Claim 43, wherein said processor determines

diameters of said two or more images based on said circumferential

extrapolations and calculates a three-dimensional velocity of said ball

based in part on a comparison of said diameters.

45. The apparatus of Claim 43, wherein said processor calculates a

diameter based on said circumferential extrapolation and calculates a

three dimensional velocity of said ball based in part on said diameter.

46. The apparatus of any of Claims 34 or 35, wherein said processor

automatically finds a perimeter of at least one image and calculates a

circumferential extrapolation of said image.

47. The apparatus of Claim 46, wherein said processor determines

diameters of said two or more images based on said circumferential

extrapolations and calculates a three-dimensional velocity of said ball

based in part on a comparison of said diameters.

48. The apparatus of Claim 46, wherein said processor calculates a

diameter based on said circumferential extrapolation and calculates a

three dimensional velocity of said ball based in part on said diameter.

49. The apparatus of any of Claims 34 or 35, wherein said processor

calculates sidespin on said ball based in part on curvatures of said

marking on said images.

50. The apparatus of Claim 49, wherein said processor calculates a

circumferential extrapolation of two or more of said images.

51 . The apparatus of Claim 50, wherein said processor calculates three-

dimensions of velocity based in part on a comparison of diameters of two

or more of said circumferential extrapolations.

52. The apparatus of Claim 51 , wherein said processor calculates sidespin

based in part on curvatures of said marking on said images.

53. The apparatus of any of Claims 34 or 35, wherein said one or more

dynamic parameters are selected from the group of dynamic parameters

consisting of backspin, sidespin and three-dimensional velocity.

54. The apparatus of any of Claims 34 or 35, wherein said one or more

dynamic parameters are determined based on a diameter calculated based

on an automatic circumferential extrapolation of at least one image, the

curvature of the marking on at least one image, and automatic linear

extrapolations of the markings on at least two images.

55. The apparatus of Claim 54, wherein said one or more dynamic

parameters include at least one of three-dimensional velocity, sidespin,

and backspin.

56. The apparatus of any of Claims 34 or 35, wherein said one or more

dynamic parameters include sidespin.

57. The apparatus of any of Claims 34 or 35, wherein said one or more

dynamic parameters include three-dimensional velocity.

58. The apparatus of Claim 34, further comprising two sensors, said

processor for receiving signals indicative of when the golf club is

detected by each of the two sensors and estimating when the golf ball

will be within a view of said camera for capturing said one or more

images based on the received signals.

59. The apparatus of any of Claims 35-36, wherein said one or more

sensors include at least two sensors, wherein said processor receives

signals indicative of when the golf club is detected by each of the at least

two sensors and estimates when the golf ball will be within a view of

said camera for capturing said one or more images based on the received

signals.

60. An apparatus for determining one or more dynamic parameters of a

golf ball after impact with a golf club head based on two or more images

of said golf ball captured after said impact and for calculating one or

more parameters of a total flight path of said golf ball based on said one

or more dynamic parameters, comprising:

an image capture device including a camera for capturing two or more

images of the golf ball after impact with the golf club head; and

a processor connected with said image capture device for

automatically determining and comparing three-dimensional spatial positions

of said two or more images and calculating a three-dimensional velocity

based in part on said three-dimensional spatial position determination and

comparison.

61 . The apparatus of Claim 60, wherein said processor automatically

determines circumferential extrapolations of perimeters of said images

from which said three-dimensional spatial positions are determined.

62. The apparatus of Claim 60, wherein said three-dimensional spatial

positions are determined based at least in part on a determination of

diameters of said images.

63. The apparatus of Claim 62, wherein said processor automatically

determines circumferential extrapolations of perimeters of said images

from which said diameters are determined.

64. An apparatus for determining one or more dynamic parameters of a

golf ball after impact with a golf club head based on one or more images

of said golf ball captured after said impact and for calculating one or

more parameters of a total flight path of said golf ball based on said one

or more dynamic parameters, comprising:

an image capture device including a camera for capturing one or more

images of the golf ball after impact with the golf club head; and

a processor connected with said image capture device for determining

a three-dimensional spatial position of the geometric center of at least one image and calculating a three-dimensional velocity based in part on said

three-dimensional spatial position determination.

65. The apparatus of Claim 64, wherein said processor automatically

determines a circumferential extrapolation of a perimeter of said image

from which said three-dimensional spatial position is determined.

66. The apparatus of Claim 65, wherein said processor automatically

determines the diameter of said image based on said circumferential

extrapolation, and determines said three-dimensional spatial position

based on said diameter determination.

67. The apparatus of any of Claims 64-66, wherein said three-dimensional

velocity is also based at least in part on a timing from a timing of impact

to a timing of capturing of said image.

68. The apparatus of Claim 67, wherein said three-dimensional velocity is

also based on a three-dimensional spatial position of said ball at said

impact location.

69. An apparatus for determining one or more dynamic parameters of a

more parameters of a total flight path of said golf ball based on said one

or more dynamic parameters, comprising:

a first and a second sensors spaced-apart along a golf swing path for

detecting a golf club head at two different points during a downswing

portion of a golf swing;

an image capture device including a camera for capturing one or more

images of the golf ball after impact with the golf club head; and

a processor for receiving signals indicative of when the golf club is

detected by each of the two sensors and estimating when the golf ball

will be within a view of said camera for capturing said one or more

images.

70. The apparatus of Claim 69, at least one of said sensors further for

triggering the capturing of the images by the camera.

71 . The apparatus of any of Claims 69 or 70, wherein the one or more

sensors are one or more photosensors that sense the club head as the

club head moves past the one or more sensors during a downswing prior

to impact with the ball.

72. The apparatus of Claim 70, wherein said at least one of said sensors

triggers a shuttering of said camera.

73. The apparatus of any of Claims 70 or 72, wherein said at least one of

said sensor triggers a flashing of one or more flashlamps of said camera.

74. An apparatus for determining one or more dynamic parameters of a

golf ball after impact with a golf club head based on two or more images

of said golf ball captured after said impact and for calculating one or

more parameters of a total flight path of said golf ball based on said one

or more dynamic parameters, comprising:

a first and a second sensors spaced-apart along a golf swing path for

detecting a golf club head at two different points during a downswing

portion of a golf swing;

an image capture device including a camera for capturing two or more

images of the golf ball after impact with the golf club head; and

a processor for receiving signals indicative of when the golf club is

detected by each of the two sensors, calculating the speed of the club

head during the downswing, calculating one or more dynamic parameters

of the golf ball based on said two or more images and calculating the

transfer efficiency of the club head to the golf ball at impact based at least in part on said club head speed and said one or more dynamic

parameters of said golf ball.

75. The apparatus of Claim 74, wherein said one or more dynamic

parameters include three-dimensional velocity, backspin and sidespin.

76. The apparatus of Claim 74, wherein said transfer efficiency is

determined relative to other transfer efficiencies determined for other

impacts of other golf swings.

77. The apparatus of any of Claims 60, 64, 69 or 74, wherein said golf ball

has a marking that is at least halfway circumambulatory of the surface of

said golf ball such that said marking is at least partially within the view of

said camera for any rotational position of said golf ball when said images are

taken.

77. The apparatus of Claim 77, wherein said marking is substantially a

straight line within the plane of the surface of the ball.

78. The apparatus of Claim 77, wherein sidespin on said golf ball is

determined based on curvatures of said marking in said images.

79. The apparatus of Claim 77, wherein said processor automatically finds

said markings are calculates linear extrapolations of said markings in said

images and determines backspin based on a comparison of said linear

extrapolations.

80. The apparatus of Claim 77, wherein said processor automatically

determines a circumferential extrapolation of at least one image,

calculates a three-dimensional spatial position from said circumferential

extrapolation and determines a three-dimensional velocity based at least

in part on said three-dimensional spatial position.

81. The apparatus of Claim 80, wherein said processor calculates a

diameter of said at least one image from said circumferential

extrapolation and calculates said three-dimensional extrapolation based in

part on said diameter.

82. The apparatus of any of Claims 1 , 7, 34, 60, 64, 69 or 74, wherein

said apparatus also captures an image of said golf ball and said golf club

at impact such that the relative orientation of said club with respect to

said ball may be evaluated.