text: referring now more particularly to fig1 the receptor for the radiation beam from the head of the user is shown generally at 10 with the source 11 positioned on a cap which could be worn by the user . the receptor may be an external item , or built into the sensing and recording device 15 . 11a is a beam of radiation from the source 11 . this radiation beam 11a can be visible light or a radio frequency beam or a comparable form of radiation . the simulated golf club 13 is shown emanating rays of light 14 onto the sensing and recording device 15 for home use and connected to receptor 10 by electrical lead 16a . referring now more particularly to fig2 the receptor 10 is shown with a sensor and light display 17 for detecting the beam of radiation from the head movement detector and displaying this information . the recording and detecting device 15 is shown provided with a plurality of registers that display distance traveled by the ball 26 , club head speed 27 , and tempo 28 . the registers also perform the functions of displaying a selected iron club , putter , or wedge 26 , displaying a selected wood club 27 . the sensor 26a is used to change the selected iron club , putter or wedge . the sensor 27a is used to change the selected wood club . the sensors 26a and 27a are activated by pointing the projected club head image at the desired sensor . light displays 23 -- 23 indicate one of nine possible trajectories of the ball resulting from the golf swing . displays 25 -- 25 show the direction of the follow through as being straight , slightly left , slightly right , extremely left or extremely right . displays 24 -- 24 show the position of the club face at impact as being center , slightly toward the heel , slightly toward the toe , extremely toward the heel or extremely toward the toe . displays 24b -- 24b indicate the altitude of the club with respect to the ball . these displays indicate if the club is too high , too low or if the club is at the proper elevation when striking the simulated ball . displays 21 -- 21 display the angle of the club face at impact . guide stripes 20 -- 20 are provided in the vicinity of the golf ball target for the purpose of determining the correct stance for the golfer for a particular club . the projected image of the club head will fit exactly between the stripes when the user is at the appropriate distance from the target . if the user is too close , the image will be too small and if the user is too far away , the image will be too large . sensors 24a -- 24a detect the angle of the club face at impact and the position of the club with respect to the ball . these sensors also determine if the club is the proper altitude . the timing cycle to determine the tempo of the swing and the velocity of the club head begins as the light passes over the sensors . sensors 25a -- 25a detect the direction of the follow through of the swing . these sensors are also used to stop the timing cycle that indicates the club head speed . the simulated golf club 13 contains a solid state led light source which operates in a modulated , i . e ., pulsed mode . the frequency of the pulses of light is much higher than the frequency of normal room lighting . the various photosensors in the apparatus generate a proportional signal when the light from the club 13 impinges thereon . the signal is then applied to a highpass filter which eliminates effects of ambient light and activates digital logic circuits . a microprocessor monitors the status of the logic signal from each sensor to determine the exact moment at which the light from the club reaches the individual sensors in the array . the tempo of the golf swing is measured from the point at which the golfer begins the back swing to the point at which the impact occurs . each swing begins by placing the club light 14 adjacent to the simulated ball 22 in the normal way in which a golfer addresses the ball . this necessarily causes the light 14 to illuminate the impact sensors 24a -- 24a . when the microprocessor detects this light it begins a timing cycle and ends the timing cycle when the light reaches the impact sensors 24a -- 24a again at the time of impact . the elapsed time is a measurement of the tempo . the club face angle at impact is measured by the microprocessor monitoring the increment of time from which the first sensor , among the sensors 24a -- 24a , is active until the adjacent sensor 24a is active . for an ideal swing the front edge of the light is perpendicular to the desired path of the ball which makes the front edge of the light virtually parallel to the row of sensors 24a -- 24a . as a result , the time interval from the first active sensor to the adjacent sensor is measured in microseconds . the larger the time interval the larger the club face angle . the microprocessor also monitors the time interval from which the impact sensors 24a -- 24a are activated until the follow - through sensors 25a -- 25a are activated . this measured time interval allows the club speed to be calculated because the distance between the two rows of sensors is known . impact position on the face of the club is determined by the total number of sensors active at the point of impact . if four or more sensors 24a -- 24a are active at the point of impact it is determined that the light is too large as it passes through the ball , therefore , it is assumed that the golf swing generates a club head that is too far off the ground . conversely , if only one or two sensors are active the light must be too small indicating that the club is too close to the ball . this method of measuring impact position is dependent upon a selection of club image sizes for different clubs . the club path is determined by a comparison of the sensors 24a -- 24a active at impact and the sensors 25a -- 25a active at follow - through . if the respective sensors from the two rows are in line , the swing is determined to be straight . if the active sensors have different relative positions , the swing is determined either to be toward the inside or toward the outside of the ball path . the ball path is determined by a combination of the club face angle at impact and the path of the club . the path of the club determines the direction in which the ball takes off from the tee and the relative angle of the club face determines if the ball will fly straight or curve to the right or the left when it is in the air . nine flight paths are possible as a result of three possible club face angles and three possible club paths . the ball flight distance is calculated by multiplying club speed by a distance factor for each type of club . percentages are subtracted from distance for inaccuracies . referring now more specifically to fig3 the simulated golf ball 22 is shown . the unit may be powered by ac or dc power sources . batteries for dc use are inserted at 31 . the on - off switch is shown at 30 and an audio response speaker , which simulates the sound of the club striking a ball is shown at 32 . connections for peripheral devices are shown at 33 -- 33 . referring now more specifically to fig4 and 4a , the simulated golf club 13 is shown . the club projects an image 41 for the benefit of the user to position the club to address the golf ball . the club 13 provides a means of selection to change the projected image of the club 13 to represent several different club types , including woods , long irons , medium irons , short irons , putter and wedge . within the club , a disc 42 is provided as shown in fig4 a , with 4 distinct cut - out shapes 43 -- 43 . each cut - out masks the light source to generate a distinct size and shape for the projected image . the disc can be rotated in increments of 90 degrees to select the appropriate mask . the image size varies for different types of clubs to allow the user to adjust his stance to simulate that of playing with actual clubs . referring now more particularly to fig5 the simulated golf club is shown at 13 containing an internal dc power source 51 , a conventional switch means 54 for turning said power source 51 on and off a modulated solid state light source 52 , and a weight 53 to provide a collective weight of the golf club to stimulate the feel and response of a conventional club . the formulae for mass , center of mass , rotational inertia and centripetal force are applied to approximate the static and dynamic physical properties of an actual golf club . a selection mechanism 42 is used to select the image of the club head to resemble a variety of actual golf club head shapes . a lens 56 is used to project the light image and an indicator 55 is active when battery power is low . fig6 is a schematic wiring diagram of the devices shown in fig2 and fig7 with the various registers shown generally at 26 , 27 , 28 and 29 and the club head position indicators 24 -- 24 . the follow through path detectors and light displays are shown at 25 -- 25 . external club position sensors 71 -- 71 and follow through sensors 72 -- 72 from the outdoor device are shown . nine displays for the resultant ball trajectory are shown at 23 . all of these items are connected to a computer controller provided with an ac / dc power supply . outputs from the computer controller also include an annunciator 32 to simulate the sound of impact of the club head on the ball and interfaces to peripheral equipment 33 . referring now more specifically to fig7 the outdoor attachment 70 is shown . this device is used while hitting a conventional golf ball with a conventional golf club . this device contains sensors 71 that will detect the movement of an actual golf club at the point of impact and sensors 72 which are activated by the motion of the follow through of the golf club swing , and send impulses to the receptor 15 allowing information about the golf swing to be displayed in a similar manner as described above . referring now more particularly to fig8 there is shown a detail of the schematic wiring diagram of the device shown in fig1 . the transmitting device consists of a motion sensor 81 , a timer 82 , and a transmitter 83 , which the golfer wears on a visor cap . the transmitting device is powered by a battery . the receiving device consists of a means of receiving the signal from the transmitter 84 and a latch 85 , which stores the level of the received signal at the instant of the golf swing , thus synchronizing the measurement of the golfer &# 39 ; s head movement with the swing of the club . a timer 86 is included to operate the visual indication 87 on a display device . when the motion sensor 81 is activated , it triggers a timing circuit 82 which in turn enables the transmitter 83 for an interval of approximately 1 second . the receiver 84 detects the signal , and provides an input to the latching circuit 85 . the latching circuit passes the state of the input signal to the output at the instant that the golf swing occurs . if the receiver 84 is active at the time of the swing , the latching circuit enables a timer 86 to generate a visual indication on the display 87 . if the receiver does not detect a transmitted signal at the time of the swing , the timer 86 and display 87 will remain inactive . referring now more particularly to fig9 the complete golf practice system is shown with peripheral equipment . specifically , these items include : a video disk adapter 91 and a television monitor 92 for video displays ; a computer 93 for video , animated graphics or other output ; a modem 94 for transmitting and receiving golf practice or golf game results to and from remote locations ; and a printer 95 for generating a printed record of golf practice or other output ; and an outdoor mat 96 and ball 97 . the interface between the golf practice apparatus and these peripheral devices is in rs - 232 serial data connection operated 9600 baud rate in the preferred embodiment of the invention . this type of data connection is manufactured by a number of companies , among which is ibm , logitech and hayes . other serial data communication interfaces work equally well , such as rs - 485 or rs - 422 . parallel data interfaces also can be used . in the preferred embodiment of this invention , the data protocol is comprised of a string of ascii transmitted from the golf apparatus . the ascii characters in the string enumerate the club &# 39 ; s speed and distance as numeric values and appropriate numeric codes to specify ball trajectory , golf club face orientation , club path , etc . values in the string are delineated by carriage return and line feed characters . each string begins with an upper case alphabet character and ends with the exclamation character ( exclamation point ). there are other protocols that are equally well suited to this application . while this invention has been described in its preferred embodiment , it is to be appreciated that variations therefrom may be made without departing from the true scope and spirit of the invention .