Systems for determining distances to and locations of features on a golf course

A golfer wishing to know the distance to a specified feature on a golf course, such as the pin on the next green, operates a portable interrogation unit, which transmits an interrogation signal including a request for the distance to the location of the specified feature. Three remote stations located to define a triangle encompassing a substantial portion of the course receive the interrogation signal and communicate interrogation information signals to a central station. The interrogation information signals include the interrogation signal data, remote station identification data, and pertaining to the location of the source of the interrogation signal relative to the remote station. The central station includes a memory which stores the locations of various predetermined features on the course and a CPU which processes the interrogation information signals from the remote stations to determine the location of the portable interrogation unit and further processes the determined unit locations with the location of the specified feature to determine the distance from the portable unit to the specified feature. The central station transmits a response signal to the portable unit indicating the determined distance, which the portable unit then displays. To survey the locations of the various predetermined features on the course, a portable survey unit is substituted for the portable interrogation unit and transmits a survey signal including feature identification data. The CPU determines the location of the portable survey unit and causes such location to be stored in an area of the memory addressed by the feature identification data in the survey signal.

BACKGROUND OF THE INVENTION 
The present invention generally pertains to electronic communications and 
is particularly directed to improved systems for determining distances to 
and locations of predetermined features on a golf course. 
Golfers are particularly interested in determining the distance to the pin 
from their location on the course. In a system described in U.S. Pat. No. 
3,868,692 to Woodward et al, separate transmitters are located at each 
hole on the golf course and transmit RF signals at separate frequencies 
associated with the respective holes. The golfer carries a portable unit 
which is tunable to any of the associated frequencies to identify the hole 
of interest; determines distance to the green based upon the strength of 
the received signal at the tuned frequency; and displays the determined 
distance to the golfer. 
In another system described in U.S. Pat. No. 4,136,394 to Jones et al, a 
transponder is mounted at or near the pin on each green on the course and 
the golfer carries a portable unit which transmits an RF signal to the 
transponder. The transponder responds to receipt of the RF signal by 
transmitting an acoustic or sonic signal. The portable unit receives the 
acoustic or sonic signal; determines distance to the pin based upon the 
elapsed time between transmission of the RF signal and receipt of the 
acoustic or sonic signal and displays the determined distance to the 
golfer. 
SUMMARY OF THE INVENTION 
The system of the present invention does not require the positioning of a 
transmitter or a transponder at each pin or at any other feature on the 
golf course to which the golfer may wish to determine distance, such as a 
dog leg or a water hazard. Further, the system of the present invention 
enables ready determination of the distance to any one of various 
predetermined features of the golf course and also enables a golfer to 
determine the distance of a drive or fairway shot. 
The system of the present invention for determining distances on a golf 
course includes a portable interrogation unit, which is carried by the 
golfer; at least three remote stations located at known locations about 
the golf course to define a triangle encompassing a substantial portion of 
the golf course; and a central station. 
The portable interrogation unit encodes and transmits an interrogation 
signal from any position on the golf course. The interrogation signal 
includes unit identification data and a request pertaining to the distance 
between the location of the portable interrogation unit and a specified 
location selected from various predetermined locations on the golf course. 
At least one of the remote stations includes a receiver for receiving the 
interrogation signal from the portable interrogation unit; and an encoder 
responsive to receipt of the interrogation signal for encoding and 
communicating an interrogation information signal to the central station, 
wherein the interrogation information signal includes remote station 
identification data, data pertaining to the location of the source of the 
interrogation signal relative to the remote station, the unit 
identification data and the request included in the received signal. The 
data pertaining to the locations of the source of the interrogation signal 
preferably indicates either the time of arrival of the interrogation 
signal or the bearing of the source of the interrogation signal relative 
to the remote station. 
Each of the other remote stations includes a receiver for receiving the 
interrogation signal from the portable interrogation unit and an encoder 
responsive to receipt of the interrogation signal for encoding and 
communicating an interrogation information signal to the central station, 
wherein the interrogation information signal includes remote station 
identification data and information pertaining to the location of the 
source of the interrogation signal relative to the remote station. 
The central station receives the interrogation information signals from the 
remote stations. The central station includes a processor for processing 
the received interrogation information signals to determine the distance 
between the portable interrogation unit and the specified location on the 
golf course indicated by the request, and responds to the distance 
determination and to the received interrogation information signals by 
encoding and transmitting a response signal addressed to the portable 
iterrogation unit indicated by the unit identification data in the 
received information signals. The response signal indicates the requested 
distance. 
The portable interrogation unit further includes a receiver for receiving 
the response signal addressed to the portable interrogation unit and a 
decoder which is responsive to the response signal for displaying an 
indication of the requested distance. 
In another aspect, the present invention combines the remote stations and 
the central station with a portable survey unit to provide a system for 
surveying locations of predetermined features of a golf course. The 
portable survey unit encodes and transmits a survey signal from any 
feature on the golf course. The survey signal includes identification of a 
specified predetermined feature selected from various predetermined 
features on the golf course, such as the pin locations, the tee locations, 
locations of dog legs, and both the near side and far side of water 
hazards. 
The remote stations receive the survey signal and respond thereby by 
encoding and communicating survey information signals to the central 
station. The survey information signals include remote station 
identification data for each remote station, data pertaining to the 
location of the source of the survey signal relative to each remote 
station, and the feature identification data included in the received 
survey signal. 
The central station receives the survey information signals from the remote 
stations. The central station processor processes the received survey 
information signals to determine the location on the golf course of the 
feature indicated by the feature identification data in the survey signal. 
The golf-course-feature locations determined by the processor are stored in 
a memory of the processor in storage areas addressed by the feature 
identification data portion of the received survey informations signals. 
The golf-course-feature locations are retrieved from the memory for making 
distance determinations pertaining to such locations. 
The survey system of the present invention enables the feature locations 
stored in the memory to be readily changed when pin and tee locations are 
changed on the golf course. 
Additional features of the present invention are described in relation to 
the description of the preferred embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIG. 1, a preferred embodiment of the system of the present 
invention includes a portable unit 10, three remote stations 12, 14 and 16 
and a central station 18. 
The three remote stations 12, 14, 16 are located at known locations about a 
golf course 20 to define a triangle encompassing a substantial portion of 
the golf course 20. 
The system for determining distances on the golf course determines the 
distance between the location of the portable unit 10 and a specified 
location selected from various predetermined locations on the golf course 
20. Referring to FIG. 2, the predetermined locations on the golf course 20 
include the locations of various predetermined features on the golf 
course, such as the location of a pin 22 on a green 24, the location of a 
dog leg 26, and the locations of both the near side 28 and the far side 30 
of a water hazard 32 as one approaches the green 24. The locations chosen 
to define the dog leg 26 and the near and far sides 28, 30 of the water 
hazard 32 are along the centerline of the fairway 34. 
Referring to FIG. 3, the preferred embodiment of the portable unit 10 
includes a keyboard 36, an encoder 38, a transmitter 40, an antenna 42, a 
receiver 44, a timer circuit 45, a decoder 46, and a display 48. The 
preferred embodiment of the keyboard and display of the portable 
interrogation unit are illustrated in FIG. 4. 
The keyboard includes keys and associated indicia indicating golfer number 
(G1, G2, G3 and G4); the tee that is used by the golfer, i.e. men's (M), 
ladies (L) or professional (P); the hole number (1, 2, 3, 4, 5, 6, 7, 8, 9 
and 0); and various distance requests, i.e. distance to the pin (TO PIN), 
distance to dog leg (DOG LEG), distance of drive (DRIVE), distance of 
fairway shot (FWY SHOT), distance to the near side of a water hazard 
(WATER HAZARD NEAR SIDE) and distance to the far side of the water hazard 
(WATER HAZARD FAR SIDE). An ON/OFF key also is included. The display of 
the portable interrogation unit of FIG. 4 includes a first portion 48a for 
displaying a request for information and a second portion 48b for 
displaying the response to such request. 
The encoder 38 responds to operation of the keyboard 36 by encoding 
interrogation signals that are provided on lines 50 to the transmitter 40 
and the decoder 46. The transmitter 40 is coupled to the antenna 42 for 
transmitting the interrogation signals to the remote stations 12, 14 and 
16 from any position on the golf course 20. The interrogation signals are 
transmitted as digital signals on an RF carrier. 
Each interrogation signal includes portable unit identification data, 
golfer identification data and a request pertaining to the distance 
between the location of the portable interrogation unit 10 and a specified 
location selected from various predetermined locations on the golf course 
20. 
The decoder 46 decodes the interrogation signal on line 50 to cause the 
request to be displayed in the first portion 48a of the display, as 
illustrated in FIG. 4. In the illustrated example, golfer G1, who is 
playing from the mens' tees, has requested the distance to the pin on the 
5th hole. Data pertaining to the tee from which the golfer is playing is 
included in the interrogation signal only when entered by operation of the 
keyboard 36, and is required when the golfer requests the distance of his 
drive. 
Alternative preferred embodiments of the remote stations 12, 14, 16 are 
described with reference to FIGS. 5 and 6. In the embodiment of FIG. 5, 
the remote stations each include a receiver 52, a clock 54, an encoder 56 
and an antenna 58. 
Interrogation signals from portable interrogation units on the golf course 
are received by the remote station antenna 58 and provided to the receiver 
52 and thence to the encoder 56. The clock 54 provides a timing signal on 
line 60 to the encoder 56. The encoder 56 responds to receipt of the 
interrogation signal by encoding and communicating an interrogation 
information signal on line 62 to the central station 18. 
The interrogation information signal on line 62 from each remote station 
includes remote station identification data and the time of arrival of the 
interrogation signal at the remote station, as determined from the timing 
signal on line 60. The interrogation information signal provided on line 
62 from at least one of the remote station encoders 56 also includes the 
portable unit identification data, golfer and tee identification data and 
the distance request included in the received interrogation signal. 
In the embodiment of FIG. 6, the remote stations each include at least two 
antennas 64a, 64b, an interferometer/receiver 68 and an encoder 70. 
Interrogation signals from portable interrogation units on the golf course 
are provided by the two remote station antennas 64a, 64b to the 
interferometer/receiver 68 and the encoder 70. The interferometer provides 
a bearing signal on line 72 to the encoder 70 indicating the bearing of 
the source of the received interrogation signal relative to the remote 
station. The encoder 70 responds to the receipt of the interrogation 
signal by encoding and communicating an interrogation information signal 
on line 62 to the central station 18. 
The interrogation information signal on line 62 from each remote station 
includes remote station identification data, and information indicating 
the bearing of the source of the interrogation signal relative to the 
remote station as determined from the bearing signal on line 72. The 
interrogation information signal provided on line 62 from at least one of 
the remote station encoders 56 also includes the portable unit 
identification data, golfer and tee identification data and the distance 
request included in the received interrogation signal. 
The interrogation information signals are communicated from the three 
remote stations 12, 14 and 16 via lines 62a, 62b and 62c, respectively, to 
the central station 18 (FIG. 1). 
Referring to FIG. 7, the central station includes a decoder 74, a processor 
including a central processing unit (CPU) 76 and a memory 78, an encoder 
80, a transmitter 82 and an antenna 84. 
The interrogation information signals received on lines 62a, 62b and 62c 
from the respective remote stations 12, 14 and 16 are decoded by the 
decoder 74 and processed by the CPU 76 to determine the distance between 
the portable interrogation unit 10 and the specified location on the golf 
course indicated by the request included in the received interrogation 
information signal. 
The memory 78 stores data indicating the location of each of the various 
predetermined locations on the golf course. The stored data indicates the 
coordinates of the various features on the golf course, such as the 
locations of the pins, tees, dog legs and water hazards. The storage of 
the golf-course-feature-indication data in the memory 78 is described 
below with reference to the discussion of the preferred embodiment of the 
golf course survey system of the present invention. The memory 78 also 
stores data indicating the location of each of the remote stations 12, 14, 
16. 
The CPU 76 processes the source-location information in the interrogation 
information signals received on lines 62a, 62b and 62c in relation to 
remote-station-location data retrieved from the memory 78 to provide an 
indication of the coordinates of the location of the portable 
interrogation unit 10 on the golf course. When the system includes the 
remote station embodiment of FIG. 5, the CPU 76 processes the information 
in the interrogation information signals on lines 62a, 62b and 62c 
indicating the relative times of arrival of the interrogation signal at 
the three remote stations 12, 14, 16 together with the associated remote 
station identification data in such signals and the 
remote-station-location data retrieved from the memory 78 to determine the 
coordinates of the location of the portable interrogation unit 10 on the 
golf course. Such determination is made in accordance with typical prior 
art range determination processing techniques. 
When the system includes the remote station embodiment of FIG. 6, the CPU 
processes the information in the interrogation information signals on 
lines 62a, 62b and 62c indicating the bearing of the portable 
interrogation unit 10 relative to the locations of the three remote 
stations together with the associated remote station identification data 
in such signals and the remote-station-location data retrieved from the 
memory 78 to determine the coordinates of the location of the portable 
interrogation unit 10 on the golf course. Such determination is made in 
accordance with typical prior art range determination processing 
techniques. 
Alternatively, the memory 78 contains look-up tables from which the 
coordinates of different locations on the golf course can be retrieved by 
the CPU 76 upon the memory 78 being addressed by the source-location 
information associated with the respective remote station identification 
data in the interrogation information signals received on lines 62a, 62b 
and 62c. The source-location information is either the 
relative-time-of-arrival information or the bearing information described 
with reference to the remote station embodiments of FIGS. 5 and 6, 
respectively. The degree of resolution of the different locations is 
dependent upon the amount of memory capacity that is dedicated to the 
look-up tables. 
The CPU 76 accesses the memory 78 in response to the specified location 
included in the request portion of the received interrogation information 
signals on lines 62a, 62b and 62c to retrieve an indication of the 
coordinates of the specified location on the golf course. The CPU 76 then 
processes the indication of the coordinates of the location of the 
portable interrogation unit and the indication of the coordinates of the 
specified location to determine the distance between the portable 
interrogation unit 10 and the location on the golf course specified in the 
distance request portion of the interrogation signal. 
The portable interrogation unit identification data in the interrogation 
information signals received on lines 62a, 62b and 62c and decoded by the 
decoder 74 is transferred by the CPU 76 to the encoder 80. 
The encoder 80 responds to the distance determination and by the CPU 76 and 
to the received interrogation information signals from lines 62a, 62b and 
62c by encoding a response signal addressed to the portable interrogation 
unit indicated by the unit identification data in the received 
interrogation information signals. The response signal indicates the 
requested distance. The encoder 76 provides the response signal to the 
transmitter 82, which is coupled to the antenna 84 for transmitting the 
response signal. The response signal is transmitted as a digital signal on 
an RF carrier. 
The transmitted response signal is received and provided by the antenna 42 
to the receiver 44 and thence to the decoder 46 in each portable 
interrogation unit (FIG. 3). If the portable interrogation unit is the 
unit to which the response signal is addressed, the decoder 46 decodes the 
response signal and causes the determined distance to be displayed on the 
"response" portion 48b of the display, as illustrated in FIG. 4, where the 
exemplary distance is shown as 175 yards. 
If multiple interrogation signals were transmitted relatively 
simultaneously from separate portable interrogation units 10, the system 
would not provide a response addressed to all of such interrogation units. 
If a response signal addressed thereto is not received by the portable 
interrogation unit 10 within a predetermined time after the interrogation 
signal is encoded by the encoder 38, the words TRY AGAIN are displayed in 
the request portion 48a of the display. Such a display is facilitated by 
operation of the timer circuit 45. 
The timer circuit 45 begins counting time in response to receipt of the 
encoded interrogation signal on line 50. The timer circuit 45 is reset by 
a reset signal that is provided on line 51 by the decoder 46 when the 
decoder 46 receives a response signal from the central station 18 
addressed to the interrogation unit. If the timer 45 does not receive a 
reset signal on line 51 from the decoder 46 before the predetermined time 
for receipt of the response signal has elapsed, the timer resets itself 
automatically and provides an error signal on line 53 to the decoder 46. 
The decoder 46 responds to the error signal on line 46 by causing the 
words TRY AGAIN to be displayed in the request portion 48a of the display. 
One of the distance requests pertains to the distance of a fairway shot. To 
determine the distance of a fairway shot in reponse to an interrogation 
signal transmitted from a portable interrogation unit 10 located at the 
resultant lay of the ball on the course, the CPU 76 must process the 
indication of the coordinates of the location of the portable unit 10 in 
relation to the indication of the coordinates of the location from which 
the fairway shot was taken. Accordingly, the interrogation signal 
transmitted from the portable interrogation unit 10 necessarily includes 
golfer identification data; the interrogation information signal 
communicated to the central station 18 from at least one of the remote 
stations 12, 14, 16 necessarily includes data identifying a given golfer 
in accordance with the golfer identification data in the received 
interrogation signal; and the memory 78 stores an indication of the 
coordinates of the last previous location from which an interrogation 
signal was transmitted from the portable interrogation unit of the given 
golfer. The last portable-interrogation-unit-location coordinate 
indication associated with a given golfer is retrieved from the memory 78 
by the CPU 76 when the request and golfer identification data portion of 
the next received information signals including data identifying the given 
golfer indicates a fairway shot, and thereby indicates the last previous 
location of the given golfer as the specified location to which the 
distance from the portable interrogation unit 10 is to be determined. 
The preferred embodiment of the system of the present invention for 
surveying locations of predetermined features on a golf course utilizes 
many of the components of the distance determination system described 
above. In the surveying system, a portable survey unit is substituted for 
the portable interrogation unit. 
Referring to FIG. 1, the portable survey unit 10 encodes and transmits a 
survey signal from any feature on the golf course. The survey signal 
includes identification of a specified predetermined feature selected from 
various predetermined features on the golf course, such as the locations 
of the pins 22 on each green 24, the location of each dog leg 26, the 
locations of both the near side 28 and the far side 30 of a water hazard 
32, and the locations of the drive markers 85 on the respective ladies', 
mens' and professional tees 86, 88 and 90. The locations chosen to define 
the dog leg 26, the near and far sides 28 and 30 of the water hazards 32, 
and the drive markers 85 are along the centerline of the fairway 34. 
The preferred embodiment of the keyboard and display of the portable survey 
unit are illustrated in FIG. 8. 
The keyboard includes keys and associated indicia indicating the hole 
number (1, 2, 3, 4, 5, 6, 7, 8, 9 and 0); tee locations used by men (M), 
ladies (L) and professionals (P); and various features on the golf course, 
i.e. pin locations (PIN), dog leg location (DOG LEG), and water hazard 
locations (WATER HAZARD NEAR SIDE) and (WATER HAZARD FAR SIDE). An ON/OFF 
key and CLEAR and ENTER function keys also are included. The display 
includes a first portion 48c for displaying an indication of the course 
feature to be surveyed and a second portion 48d for displaying function 
status instructions. 
FIG. 3 also is applicable to the portable survey unit. 
The encoder 38 responds to operation of the keyboard 36 by encoding survey 
signals that are provided on lines 50 to the transmitter 40 and the 
decoder 46. The transmitter 40 is coupled to the antenna 42 for 
transmitting the survey signals to the remote stations 12, 14 and 16 from 
any position on the golf course 20. The survey signals are transmitted as 
digital signals on an RF carrier. 
Each survey signal includes identification of a specified predetermined 
feature selected from various predetermined features on the golf course. 
The decoder 46 decodes the survey signal on line 50 to cause the specified 
feature to be displayed in the first portion 48c of the display, as 
illustrated in FIG. 8. In the illustrated example, the specified feature 
is the mens' tee for the 7th hole. The person surveying the course would 
stand halfway between the drive markers 85 on the mens' tee 88 of the 7th 
hole when transmitting the survey signal illustrated in this example. 
After the keyboard has been operated to provide the specified feature data, 
as displayed in the feature portion 48c of the display, the person using 
the portable survey unit then depresses the ENTER key, which causes the 
survey signal to be transmitted. 
The remote stations 12, 14, 16 receive the survey signal and respond 
thereby by encoding and communicating survey information signals to the 
central station 18 in the same manner as the interrogation information 
signals are encoded and communicated, as described above. The survey 
information signals include remote station identification data for each 
remote station data pertaining to the location of the source of the survey 
signal relative to each remote station, and the feature identification 
data included in the received survey signal. 
The central station 18 receives the survey information signals from the 
remove stations 12, 14, 16. The central station CPU 76 processes the 
survey information signals received on lines 62a, 62b and 62c to determine 
the coordinates of the location on the golf course of the feature 
indicated by the feature identification data in the survey signal in the 
same manner as the interrogation information signals are processed to 
determine the location of the portable interrogation unit on the golf 
course, as described above. 
The golf-course-feature-location coordinates determined by the CPU 76 are 
stored in the memory 78 in storage areas addressed by the feature 
identification data portion of the received survey informations signals. 
The golf-course-feature-location coordinates subsequently are retrieved 
from the memory 78 for making distance determinations pertaining to such 
feature locations in response to requests pertaining thereto in 
interrogation information signals. 
Upon the coordinates of the location of the specified feature being stored 
in the memory 78, the CPU 76 causes the encoder 80 to provide a clear 
signal to the transmitter 82. The clear signal is addressed to the 
portable survey unit and is transmitted from the antenna 84. 
The antenna 42 of the portable survey unit receives the clear signal and 
provides it to the receiver 44 and decoder 46, which causes a CLEAR 
indication to be displayed in the status portion 48d of the portable 
survey unit display. 
The display of the word CLEAR indicates to the operator of the portable 
survey unit that the location of the specified feature identified in the 
transmitted survey signal has been stored in the memory 78 of the central 
station 18. The operator then depresses the CLEAR key to clear the feature 
portion 48c of the display and to enable entry, encoding and transmission 
of another survey signal from another location on the golf course. Upon 
the CLEAR key being depressed, the word ENTER appears in the status 
portion 48d of the display. The operator then can proceed to operate keys 
to enter the next course feature to be surveyed in the feature portion 48c 
of the display; and he depresses the ENTER key to transmit the next survey 
signal when the portable survey unit is located at the displayed course 
feature. If a clear signal is not received by the portable survey unit 10 
within a predetermined time after the survey signal is encoded by the 
encoder 38, the words TRY AGAIN are displayed in the request portion 48c 
of the display. Such a display is facilitated by operation of the timer 
circuit 45. 
The timer circuit 45 begins counting time in response to receipt of the 
encoded survey signal on line 50. The timer circuit 45 is reset by a reset 
signal that is provided on line 51 by the decoder 46 when the decoder 46 
receives a clear signal from the central station 18. If the timer 45 does 
not receive a reset signal on line 51 from the decoder 46 before the 
predetermined time for receipt of the clear signal has elapsed, the timer 
resets itself automatically and provides an error signal on line 53 to the 
decoder 46. The decoder 46 responds to the error signal on line 46 by 
causing the words TRY AGIN to be displayed in the request portion 48c of 
the display.