System and method for measuring distance between two objects on a golf course

Claims

What is claimed is:

1. A system for providing a player on a golf course with the distance between a golf ball on said golf course and a stationary object on said golf course, where the location of said object is previously known and defined by object location data, said system comprising:

a) a first unit transmitting an error data signal to each of a plurality of mobile units on said golf course which mobile units are remotely spaced from said golf ball, said first unit including;

i) a fixed receiving means, positioned in a fixed location, said fixed location being accurately defined by known location data, said known location data preserved and stored for use, said receiving means receiving navigation signals from navigation satellites and deriving, from said navigation signals, first location data generally defining said fixed location,

ii) a location data comparing means for receiving and comparing said known location data and said first location data and for generating said error data signal corresponding to differences between said known location data and said first location data, and

iii) data transmission means for transmitting said error data signal to said mobile units;

b) each of said mobile units including;

i) a mobile receiving means for receiving navigation signals from navigation satellites and for deriving, from said navigation signals, second location data generally defining the location of said mobile unit,

ii) data receiving means for receiving said error data signal transmitted from said data transmission means,

iii) a data adjusting means for receiving said second location data from said mobile receiving means and for receiving said error data signal from said data receiving means and for adjusting said second location data with said error data signal for generating a third location data accurately defining the location of said mobile unit,

iv) a golf ball locating means for measuring and determining ball distance data defining the distance said golf ball is positioned from said location of said mobile unit and for determining a ball direction data defining the direction said golf ball is positioned from said mobile unit,

v) a data shifting means for receiving said third location data from said data adjusting means and for receiving said ball distance data and said ball direction data from said golf ball locating means and for shifting said third location data by said ball distance data and said ball direction data for generating a ball location data defining the location of said golf ball,

vi) a calculation means for receiving said object location data and said ball location data and for calculating a distance between said golf ball and said object on said golf course.

2. The system of claim 1 wherein said object is a hazard on said golf course.

3. The system of claim 1 wherein said object is a hole on a green of said golf course.

4. The system of claim 1 wherein said distance between said golf ball and said object is expressed in yardage.

5. The system of claim 1 wherein said error data signal corresponds to an inverse of the differences between said known location data and said first location data.

6. A system for measuring a distance between a golf ball on a golf course and a hole on a green of said golf course where the location of said hole is stationary and previously known and defined in hole location data, said system comprising:

a) a first receiver means in a first location, said first location known and defined in fixed location data, said first receiver means receiving navigation signals transmitted by navigation satellites and deriving a first location data from said navigation signals, said first location data defining said first location;

b) a comparator means for receiving and comparing said fixed location data and said first location data and for generating an error data signal corresponding to a differential between said fixed location data and said first location data;

c) a data transmitter means for receiving said error data signal from said comparator means and for transmitting said error data signal to mobile unit means in said system which mobile unit means are remotely spaced from said golf ball;

d) each said mobile unit means including:

i) a second receiver means, transported by said mobile unit means, said mobile unit means positionable, on demand, at a second location, on said golf course, said second location being an undefined location, said second receiver means for receiving navigation signals from navigation satellites and for deriving a second location data from said navigation signals defining said second location;

ii) a data receiving means for receiving said error data signal transmitted by said data transmitter means;

iii) a data adjusting means for receiving said second location data and said error data signal and for adjusting said second location data by said error data signal for generating an adjusted location data defining said second location:

iv) a distance measuring means for determining a distance and a direction between said golf ball and said second location and for shifting said adjusted location data in accordance with said distance and direction determined for generating a ball location data defining a location of said golf ball on said golf course, and

v) calculation means for calculating a difference between said ball location data and said hole location data and for converting said difference into a measurement of the distance between said golf ball on said golf course and said hole on said green.

7. A system for measuring a distance as in claim 6 and in which said measurement of distance is yardage.

8. A system for measuring a distance as in claim 6 and in which said first receiver means receives navigation signals on an ongoing basis.

9. A system for measuring a distance as in claim 6 and in which said error data signal corresponds inversely to said differential between said known location data and said first location data.

10. A method for measuring the distance between a golf ball positioned on a golf course and a stationary hole on a green of said golf course wherein the location of the hole is known by hole location data, comprising the steps of:

a) transporting a first global position receiver along the golf course mounted to a mobile cart and stopping said mobile cart at an undefined location on said golf course which mobile cart is remotely spaced from said golf ball;

b) positioning a second global position receiver in a fixed location and calculating a fixed location data defining said fixed location and preserving said fixed location data;

c) operating said second global position receiver, on an ongoing basis, from said fixed location for receiving first navigation signals from navigation satellites;

d) deriving first location data from said first navigation signals for defining said fixed location by said first navigation signals;

e) comparing said fixed location data with said first location data and detecting a differential between said fixed location data and said first location data;

f) generating an error signal corresponding to an inverse of said differential;

g) operating said first global position receiver from said undefined location for receiving second navigation signals from said navigation satellites;

h) deriving a second location data from said second navigation signals for defining said undefined location;

i) adjusting said second location data with said error signal for generating a first adjusted location data defining said undefined location;

j) calculating a ball distance and a ball direction between said golf ball and said undefined location, as defined by said first adjusted location data;

k) adjusting said first adjusted location data by said ball distance and said ball direction for generating a ball location data, defining a location of said golf ball; and

l) calculating a differential, in location data, between said hole location data and said ball location data and converting said differential into a measure of distance.

11. A method for measuring distance as in claim 10 and, between steps h) and i) further including the step of

delaying said second location data so that said second location data is in phase with said error signal.

12. A method for measuring distance as in claim 10 and further including the step of:

displaying said measure of distance between said golf ball location and said hole visually.

13. A method for measuring distance as in claim 12 and further including the step of:

printing said measure of distance on a substrate.

14. A method for measuring distance as in claim 12 and wherein said measured distance is yardage.

15. A method of measuring a distance as in claim 10 and further including the step of:

applying said differential data converted into said measure of distance to a speech synthesizer for audibly speaking said measure of distance.

16. A method for measuring the distance between a golf ball positioned on a fairway of a golf course and a hole on a green on said golf course, the location of said hole defined by a hole location data, comprising the steps of:

a) positioning a mobile cart transporting a mobile global position receiver on said golf course, in close proximity to said golf ball positioned on said fairway;

b) receiving navigation signals from one or more navigation satellites with said mobile global position receiver and converting said navigation signals into a first location data defining a first location of said mobile cart;

c) operating a fixed global position receiver from a known, fixed location, defined by known location data, for receiving navigation signals from said one or more navigation satellites and converting said navigation signals into a second location data defining said known, fixed location;

d) comparing said second location data with said known location data and generating a first error signal corresponding to a first differential between said second location data and said known location data;

e) changing said first location data in accordance with said first error signal into a first adjusted location data defining said first location of said mobile cart;

f) measuring a distance and a direction between said mobile cart as defined by said first adjusted location data, and said golf ball positioned on said fairway and changing said first adjusted location data in accordance with said distance and said direction so measured for generating a ball location data defining the location of said golf ball on said fairway; and

g) calculating a second differential between said ball location data and said hole location data and converting said second differential into a first distance.

17. A method for measuring a distance as in claim 16 and further including the steps of:

i) displaying said first distance on a display means.

18. A method for measuring a distance as in claim 17 and further including the step of:

ii) printing a hard copy of said first distance on substrate,

19. A method for measuring a distance as in claim 16 wherein said first distance is measured in yardage.

20. A method for measuring a distance as in claim 16 wherein said first error signal corresponds inversely to said first differential.

21. A method for determining a distance between a golf ball positioned on a golf course and a stationary object on the golf course, where the location of said object is defined in known and preserved location data, said method comprising the steps of:

a) operating a receiver from a fixed location defined accurately by a known location data, for receiving GPS navigation signals and for deriving, from said navigation signals, a first location data defining said fixed location;

b) comparing said known location data with said first location data and generating an error data corresponding to a differential between said known location data and said first location data;

c) transmitting said error data to mobile receivers on the golf course;

d) operating a mobile receiver, which is remotely spaced from said golf ball, from an undefined location on said golf course for receiving GPS navigation signals and deriving, from said navigation signals, a second location data defining said undefined location of said mobile receiver;

e) receiving said error data and applying said error data to said second location data for adjusting said second location data with said error data for generating an adjusted location data defining said undefined location;

f) determining the distance and direction between said undefined location as defined by said adjusted location data, and said golf ball and adjusting said adjusted location data by the determined distance and direction for generating a ball location data defining the location of said golf ball;

g) comparing said ball location data and said location data and calculating a difference data between said ball location data and said location data and converting said difference data into a measurement of distance between said golf ball and said object.

22. A method for determining as in claim 21 and in which step a) includes operating said fixed receiver on an ongoing basis.

23. A method for determining as in claim 21 and in which said error data corresponds inversely to said differential.

24. A method for determining as in claim 21 and further including the steps of:

i) sensing the direction and velocity of wind at said undefined location and defining said direction and velocity of wind in a wind data, said wind data being compatible with said ball location data;

ii) determining a direct flight path of a golf ball between the location of the golf ball, as defined by said ball location data and the location of said object, as defined by said location data, and converting said direct flight path into flight path data compatible with said wind data; and

iii) adjusting said flight path data by said wind data for generating an apparent flight path data for defining an apparatus flight path of said golf ball.

25. A method for measuring a distance as in claim 24 and further including the step of:

printing out the calculated distance on a substrate.

26. A method for determining as in claim 24 and further including the step of:

displaying said apparent flight path of said golf ball.

27. A method for measuring the distance between a golf ball positioned on a golf course and a stationary object on said golf course, wherein the location of said object is defined in a known and preserved location data, said method comprising the steps of:

a) operating a navigation signals receiver from a predetermined location, said predetermined location defined by a known location data, for receiving navigation signals from navigation satellites and deriving from said navigation signals a first location data defining said predetermined location;

b) comparing said known location data with said first location data and generating an error data corresponding to a differential between said known location data and said first location data;

c) transmitting said error data to mobile navigational signal receivers on said golf course which mobile navigational signal receivers are remotely spaced from said golf ball;

d) operating a mobile navigation signal receiver transported by a mobile unit at an undefined location on said golf course, said navigation signal receiver receiving navigation signals from said navigation satellites and deriving from said navigation signals a second location data defining said undefined location of said mobile receiver unit;

e) receiving said error data by said navigation signal receiver transported by said mobile unit and applying said error data to said second location data for adjusting said second location data with said error data for generating an adjusted location data defining said undefined location;

f) monitoring movement of said mobile unit and generating a local data defining movement of said mobile unit during steps d) and e);

g) adjusting said adjusted location data with said local data for generating a second adjusted location data defining said undefined location;

h) determining a distance and direction between said undefined location, as defined by said second adjusted location data, and said golf ball and adjusting said second adjusted location data by said determined distance and direction for generating a ball location data defining the location of said golf ball; and

i) comparing said ball location data and said known and preserved location data and calculating a difference data between said ball location data and said known and preserved location data and converting said difference data into a measurement data defining the distance between said ball and said object.

28. A method for measuring as in claim 27 and in which step a) includes operating said navigation signals receiver on an on-going basis.

29. A method for measuring as in claim 27 and in which said object is a hole on a green associated with said fairway.

30. A method for measuring as in claim 27 and wherein said measurement data is in yardage.

31. A method for measuring as in claim 27 and further including the steps of;

i) monitoring the direction and velocity of wind at said undefined location and converting wind direction and velocity into a wind data;

ii) determining an absolute flight path of a golf ball between the location of said golf ball, as defined by said ball location data, and the location of said object, as defined by said known and preserved location data and converting said absolute flight path into a ball flight data compatible with said wind data; and,

iii) adjusting said absolute flight path, as defined by said ball flight data with said wind data for generating an apparent flight path of said golf ball.

32. A method for measuring as in claim 31 and further including the step of:

iiii) displaying said apparent flight path of said golf ball on a display means.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to electronic communication systems for determining a measurement of the distance between two objects from a position remote from both objects. In particular, the invention is directed to an electronic system and method for determining a measurement of the distance between two objects on earth, wherein the location of one of the objects is known in a location defining data and the location of the other objects is known, but not in location defining data. The invention is particularly useful for determining a measurement of the distance between a golf ball, positioned on the fairway of a golf course, and the hole or pin on a green associated with the fairway on the golf course.

2. Prior Art

In playing the game of golf on a golf course, the player is provided with the distance, in yardage, from the tee to the pin or hole on the green for the "hole" being played. For the sake of clarity, the hole on a green of a golf course will, hereinafter be referred to as pin and the hole on a golf course, which includes the tee, the fairway and the green, will hereinafter be referred to as "hole". It will be appreciated that the hole on the green receives the shaft of a flag which identifies the number of the "hole" and that the term flag, and pin, and hole on the green all relate to and identify the same point. Often the distance between the tee or tee-off point and the pin is much farther than the ball is driven with a golf club, in a single stroke. It is usual for a golfer to drive a golf ball short of the green of the "hole" being played where the "hole" is rated par four or par five, for example. Once a golf player drives a golf ball off the tee, toward the green of the "hole" being played, the golfer is essentially left on his own to determine the yardage between the golf ball, laying on the fairway, and the pin on the green of the "hole" being played.

The prior art includes devices and systems which may be used by the golfer for determining the approximate distance between the pin and a point that approximates the location of the golf ball laying on the fairway but, for the most part, the prior art does not teach apparatus which provide a precise measurement, in standard measurement terms, of the distance between a golf ball laying on a fairway and the pin on the green associated with that fairway. U.S. Pat. No. 4,136,394, issued to Josies, et al, titled Golf Yardage Indicator System, issued in 1979, teaches a multi-unit system in which a transponder is mounted on or near the pin on the green. A portable complex transmitter/receiver carried by the golf player, is used to transmit a signal to the transponder on the green and the transponder, in response, transmits a data signal that picked up by the portable receiver. The data is analyzed for determining the distance between the transponder and the portable transmitter/receiver. The data signal is in the sonic range and sonic waves are subject to variances when projected through air, such as by air temperature and humidity. Also, a golf course usually has many changes in ground elevation which may require that the transponder be mounted above the ground, such as on the shaft of the flag used to identify the hole and green. This leads to problems because the shaft/flag is often removed from the hole on the green when golf players are playing on the green. With the shaft/flag removed from the hole the transponder on longer identifies with the hole on the green.

U.S. Pat. No. 5,044,634 to Dudley, titled Golf Information System teaches burying wires of a grid in the ground of a fairway. The grid wires emit signals which are read by a receiver. However, this system does not locate a ball lying between wires of the grid which, in order to practice the invention must be buried in the fairway. In order to bury a wire grid in the fairway, the fairway must be dug up. This is extremely expensive and interferes with the use of the golf course lot playing golf. U.S. Pat. No. 5,046,839 to Krangle, titled Golf Course Range Finder System teaches a hand-held range finder device emitting light pulses that are reflected by a reflector mounted on the shaft of the flag. This system has some of the same problems attendant with the Josies, et al teaching, plus the additional problem that in order to use the Krangle system an unobstructed view of the shaft/flag is required.

U.S. Pat. No. 3,868,692 to Woodard, et al, titled Golf Yardage Finder teaches the use of a mobile receiver and a transmitter located at the green. The transmitter emits signals which are received by the receiver and the receiver, which includes a signal field strength detecting device, measures the strength of the signal and converts the signal strength into yardage between the transmitter and the receiver, using the strength of the signal. Here again, the distance measured is the distance between the components of the measuring device, the transmitter and the receiver, not the transmitter and the ball on the fairway.

U.S. Pat. No. 4,480,310 issued to Alverez, titled Dead Reckoning Range Finding Device For Cart, teaches sensing devices, attached to a golf cart, for monitoring the wheels of the cart for measuring the distance and direction traveled by the cart. The Alvarez teaching is directed to measuring the distance and direction of the ball flight rather than measuring the distance between the ball, on the fairway, and the pin on the green.

U.S. Pat. No. 4,703,444 issued to Storms, Jr., et al, titled System For Determining Distance To And Location Of Features On A Golf Course, teaches positioning three or more remote, spaced transmitters on a golf course each of which transmit signals. A portable receiver, carried by a golfer, serves as an interrogation unit, receiving signals from the transmitters and, by triangulation, locates the position of the portable receiver. The portable receiver includes a keyboard for entering requests pertaining to distances between the receiver and another point or object on the golf course. As with other prior art, Storms, Jr., et al teaches a system which measures the distance from a receiving unit, rather than measuring from the ball on the fairway.

SUMMARY OF THE INVENTION

The present invention is an electronic communication system and method which accurately measures the distance between two objects, where the location of one of the objects is known, in coordinates and the location of the other object is known, but not in compatible terms or coordinates. The present invention is particularly useful in determining an accurate measurement of the distance between a golf ball, on the fairway of a golf course, and the hole or pin on a green of the golf course, for example. The present invention overcomes the disadvantages and shortcomings of the prior art by measuring the distance between the ball and the hole on the green rather than measuring the distance between the measuring device and the hole on the green, solving the problem in an entirely novel way.

From a broad aspect, the present invention provides a system and method by which navigation signals, transmitted from navigation satellites, in space, and received by a mobile, navigation signal receiving device, (the device hereinafter referred to as a global position receiver or GP receiver) is used to generate ground location data or coordinates, pin pointing, in stable, definite and accurate terms, the particular location of very small objects, such as a golf ball, for example.

When an object or point on the ground is fixed, such as a hole or pin on a green of a golf course, for example, a set of coordinates defining the pin point location of such object or point can be determined and noted. One method of determining coordinates defining the location of a hole or pin (hereinafter referred to as pin) on a green of a golf course, is to use a sextant to ascertain the exact latitude and longitude coordinates, defining the location in small incremental measurement terms. This may take time and effort, and may need the additional use of a chart and plotting apparatus, But, since the position of the pin is fixed and using a sextant and plotting the location of the pin on a chart may be done over an extended, interrupted period, and without interfering with golf players, coordinates or a set of coordinates, defining the exact location of the pin, may be obtained, and, since the pin location on the green is fixed, such coordinates can be preserved for later use.

When a golf player is playing golf on a golf course, it is normal to provide the golf player with the distance, in yardage, between the tee and the pin in which the ball is to be "sunk". However, often the golf ball driven, from the tee, falls substantially short of the green, especially where the "hole" is rated par four or par five. Prior to the golf player taking his "second shot", it is advantageous for the golfer to know, as accurately as possible, the measure of the distance, in yardage, between the golf ball, positioned on the fairway and the pin on the green of that fairway. Knowledge of the yardage between the golf ball and the pin is a factor in selecting the proper golf club to use for the next "shot".

When a golf ball is driven from the tee and lands on the fairway, substantially short of the green, it is not practical to determine the location of the ball by the same method used to determine the precise location of the pin.

A tape measure, stretched between the ball and the pin may be used to measure the distance between the ball and pin but this, also, is not practical, nor is the use of a tape measure acceptable while playing golf. Other methods, such as those proposed in the prior art may be used, but these, for the most part, measure the distance between the pin and the measuring device rather than the pin and the ball.

With the precise coordinates defining the location of the pin already known and preserved, the problem of finding precise, stable coordinates defining the location of the golf ball on the fairway remains. Precise, definite coordinates, defining the location of the golf ball on the fairway are needed in order to determine and measure the distance between the pin and the ball.

The present invention provides a system and method for determining the exact location of the golf ball on a fairway, in stable, definite coordinates which are compatible with the coordinates that define the location of the pin and, knowing the location of both the ball and the pin, each location being defined in sets of compatible coordinates that are both definite and stable, the distance between two locations defined by the coordinates may be determined and measured by simple mathematics.

Normally, locations defined by location coordinates derived from signals transmitted by navigation satellites are far too unstable and indefinite to positively locate a small object, such as a golf ball, for example. The instability and indefiniteness in the location coordinates derived from navigation signals transmitted by navigation satellites, are caused by noise and/or deviation signals on the normal navigation signals, some of which are inserted by government design, in order to avoid transmitting signals producing stable, definite coordinates defining pin point accurate locations. Other signal variations are a result of satellite flight variations. Although navigation signals can be processed into coordinates which clearly define a true, consistent location, the presence of noise and/or deviation signals prevent processing the signals into coordinates which define a location clearly, accurately and definitely.

However, by practicing the present invention, stable and definite ground coordinates, defining a highly accurate location of a small object, such as a golf ball, are derived from navigation signals transmitted from navigation satellites, by using two global position receivers (GP receivers) to receive concurrent navigation signals from navigation satellites in space even though the navigation signals transmitted by the satellites include noise and/or deviation signals which cause instability and indefiniteness in the coordinate data derived from the navigation signals.

A first, mobile GP receiver, positioned on a golf course, for example, in close proximity to a golf ball on the fairway, for example, is used to receive signals from the navigation satellites for converting such signals into location coordinates defining the location of the mobile GP receiver. These signals are subject to correction by an error signal generated by a second,fixedly positioned GP receiver, used to receive concurrently transmitted signals, from navigation satellites. The fixed GP receiver is used for detecting the effects of noise and/or deviation signals on location coordinate data derived from the navigation signals and for generating an error signal to overcome or eliminate the effect, on the coordinate data, of the noise and/or deviation signals on the navigation signals. The error signal generated by the fixed GP receiver is transmitted to the mobile GP receiver and is used, by the mobile GP receiver, to overcome or eliminate the effect of the noise and/or deviation signals on the location coordinates derived by the mobile GP receiver from the navigation signals received by the mobile GP receiver so that stable, definite coordinates defining the location of the mobile GP receiver may be obtained. After obtaining stable, definite coordinates defining the location of the mobile GP receiver on the golf course, the distance and direction of offset of the golf ball from the mobile GP receiver, are determined and the stable, definite coordinates, defining the location of the mobile GP receiver, are adjusted, with the offset, so as to define the location of the golf ball on the fairway of the golf course in stable, definite location coordinates.

The location of the golf ball having now been defined in stable, definite coordinates and the coordinates defining the location of the pin, previously discussed, being known and preserved, the distance between the two locations defined by the two sets of coordinates, i.e., the location of the golf ball and the location of the pin, can be determined by simple mathematics and may be expressed in a distance measurement, such as yardage, for example.

It will be appreciated that the location of the fixed GP receiver may be determined in location coordinates, using substantially the same or similar techniques used to determine the location coordinates of the pin on the green, for example. With the true location coordinates of the fixed GP receiver known, the coordinates derived from the navigation signals received from navigation satellites can be compared with the previously generated true location coordinates and any instability, indefiniteness and/or change from the true location coordinates can be recognized and may be considered a function of the noise and/or deviation signals on the navigation signals. An error or correction signal may then be generated by the fixed GP receiver, corresponding to the unstable and indefinite portions of the location coordinates.

In the preferred embodiment of the invention, the error signals generated by the fixed GP receiver are derived from the unstable and indefinite portions of the coordinates derived from the navigation signals. The error or correction signals may correspond, inversely to the unstable and indefinite portions of the location coordinates defining the location of the fixed GP receiver. The error or correction signals are used by the mobile GP receiver to stabilize and make definite the unstable and indefinite coordinates derived by the mobile GP receiver defining its location.

Alternatively, an error or correction signal may be derived by a fixed GP receiver from the navigation signals which carry the noise and/or deviation signals and the error or correction signal may be used by the mobile GP receiver to eliminate or overcome the effect of the noise and/or deviation signals carried by the navigation signals.

In accordance with the invention, the location of a golf ball on the fairway of a golf course is defined by stable and definite coordinates by a mobile GP receiver in which a GP receiver, located in a fixed, known and defined location, such as the club house of the golf course, or the proshop of the golf course, for example, is used to create an error or correction signal corresponding to the instability and indefiniteness of the coordinates derived from navigation signals transmitted by navigation satellites, defining the location of the fixed GP receiver. Since the GP receiver does not move from its fixed location, coordinates, derived from navigation signals received by it, defining its location, may be expected to be stable, consistent and definite. Any change in the stability, consistency or definiteness in the coordinates defining the location of the fixed GP receiver from its known location are viewed as caused by noise and/or deviation signals on the navigation signals. The error or correction signal, which is generated corresponds to the inverse of any change or instability in derived location coordinates from known location coordinates defining the fixed location of the fixed GP receiver.

This error or correction signal is transmitted to and used, by a mobile GP receiver to overcome or eliminate the instability and indefiniteness in location coordinates derived from navigation signals transmitted by navigation satellites, defining the location of the mobile GP receiver, caused by the noise and/or deviation signals on the navigation signals. The resultant coordinates define the location of the mobile GP receiver in stable