Apparatuses, methods and systems relating to findable golf balls

• US 20060128503A1
• Filed: 10/31/2005
• Published: 06/15/2006
• Est. Priority Date: 01/17/2003
• Status: Active Grant

• Current Assignee: Topgolf International Inc. (Topgolf Callaway Brands Corp.)
• Original Assignee: RF Corporation
• Inventors: Savarese, Chris, Glissman, John, Shea, Mark A., McGill, Susan, Gilliland, Kenneth P., Vickers, Marvin L., Fulton, Forrest F., Cadorniga, Lauro C., Scheller, James C. Jr., Marshall, Noel H.C.
• Granted Patent: US 8,002,645 B2
• Time in Patent Office: Days
• US Class Current: 473/353
• CPC Class Codes: A63B 2024/0053 for locating an object, e.g. a lost ball
• CPC Class Codes: A63B 2225/50 Wireless data transmission, e.g. by radio transmitters or telemetry
• CPC Class Codes: A63B 24/0021 Tracking a path or terminating locations
• CPC Class Codes: A63B 37/0003 Golf balls
• CPC Class Codes: A63B 37/0055 with non-spherical insert(s)
• CPC Class Codes: A63B 37/0064 Diameter
• CPC Class Codes: A63B 37/0088 Frequency
• CPC Class Codes: A63B 43/00 Balls with special arrangements

Abstract

Golf ball locators and components of such locators and methods of operating such locators and processing signals within such locators. In one aspect of the inventions described herein, an exemplary method of initializing a golf ball locator includes receiving received RF signals while also transmitting signals used to locate balls and determining a parameter representative of received signal strength of the received RF signals and setting a threshold to determine when subsequent received signals are to cause an indication of golf ball detection. In another aspect of this disclosure, the golf ball locator is a handheld unit having a volume of less than about 150 inches cubed and includes a transmitter, a transmit antenna, a receiver, a receive antenna and a processor coupled to the transmitter and to the receiver, and the handheld unit achieves a signal isolation, between a second harmonic of a transmitted signal from the transmitter and the receiver'"'"'s received signal, of greater than about 130 to 160 dB. Other aspects are also described.

Claims

1. A method of processing signals in a golf ball detector having a transmitter and a receiver, the method comprising:

transmitting radio frequency (RF) signals from the transmitter;

receiving received RF signals while the transmitting occurs;

determining a parameter representative of a received signal strength of the received RF signals;

setting a threshold for received signals to indicate golf ball detection, the threshold set based on the parameter.

2. A method as in claim 1 wherein the method is used to initialize the golf ball detector and wherein subsequently received RF signals having subsequent received signal strengths less than the received signal strength do not produce an indication of golf ball detection.

3. A method as in claim 2, the method further comprising:

positioning, prior to the determining, the golf ball detector to reduce the chance of a reception of an RF signal from a golf ball having an RF circuit, and wherein the receiving overlaps in time with the positioning.

4. A method as in claim 3, the method further comprising:

determining whether the parameter representative of the received signal strength indicates a valid initialization and, in response to the determining whether the parameter indicates a valid initialization, presenting a message which indicates whether the golf ball detector has a valid initialization.

5. A method as in claim 4 wherein the parameter is a baseline value which comprises the received signal strength of the received RF signals and a buffer value and wherein the message is at least one of a visual display or an audible sound or a vibration and wherein the baseline value can change over time as a result of changes within the golf ball detector.

92. A method as in claim 1 wherein the transmitter is positioned to direct RF signals to a source of interference which can reflect the RF signals to the receiver.

93. A method as in claim 92 wherein the source of interference includes one of a fence and a sprinkler.

94. A method as in claim 92 wherein the threshold is set to minimize the interfering effect of the source of interference.

6. A method of initializing a golf ball detector having an RF (radio frequency) transmitter and an RF receiver, the method comprising:

positioning the golf ball detector to receive RF signals from a space substantially devoid of a golf ball having an RF circuit;

observing whether the golf ball detector presents an indication of whether the initializing was valid.

7. A method as in claim 6 wherein the golf ball detector presents a first indication if the initializing was valid and a second indication if the initializing was not valid and wherein the RF signals include reflected RF signals which originated from the transmitter or harmonics of RF signals which originated from the transmitter.

8. A handheld golf ball detector comprising:

a radio frequency (RF) transmitter to transmit signals used to detect a golf ball having an RF circuit;

an RF receiver to receive RF signals from a golf ball;

a processor coupled to the RF transmitter and to the RF receiver, the processor to determine a parameter representative of a received signal strength of RF signals received while the RF transmitter is transmitting and the processor to set a threshold for received signals to indicate golf ball detection, the threshold being based on the parameter.

9. A handheld golf ball detector as in claim 8 further comprising a memory, coupled to the processor, to store the threshold and wherein the processor determines the parameter as an initialization process for using the handheld golf ball detector and wherein subsequently received RF signals having subsequent received signal strengths less than the received signal strength do not produce an indication of golf ball detection.

10. A handheld golf ball detector as in claim 9 wherein the handheld golf ball detector is positioned, prior to the processor determining the parameter, to reduce the chance of a reception of an RF signal from a golf ball having an RF circuit.

11. A handheld golf ball detector as in claim 9 further comprising:

an indicator coupled to the processor, the indicator to indicate whether the initialization process is valid, and wherein the processor determines, from the parameter, whether the initialization process is valid and, in response to determining whether the initialization process is valid, the processor causes the indicator to present a message which indicates whether the handheld golf ball detector has a valid initialization, and wherein the parameter is a baseline value which comprises the received signal strength of RF signals received while the RF transmitter is transmitting and a buffer value.

12. A machine readable medium providing executable computer program instructions which cause a processing system to perform a method in a golf ball detector, the method comprising:

transmitting radio frequency (RF) signals from a transmitter in the golf ball detector;

receiving, in an RF receiver in the golf ball detector, received RF signals while the transmitting occurs;

determining a parameter representative of a received signal strength of the received RF signals;

setting a threshold for received signals to indicate golf ball detection, the threshold set based on the parameter.

13. A machine readable medium as in claim 12 wherein the method is used to initialize the golf ball detector and wherein subsequently received RF signals having subsequent received signal strengths less than the received signal strength do not produce an indication of golf ball detection.

14. A method of locating a golf ball with a handheld golf ball detector, the method comprising:

modulating a carrier to provide a binary phase shift keyed (BPSK) modulated signal, the modulation comprising a pseudorandom binary sequence (PN) modulated on the carrier;

transmitting the BPSK modulated signal in transmitted pulses to locate a golf ball having an RF (radio frequency) circuit;

receiving as a received signal a harmonic of the transmitted pulses.

15. A method as in claim 14 wherein the received signal was despread by a ball'"'"'s RF circuit and wherein the harmonic is a 2 times harmonic and wherein a single crystal is used to generate a reference frequency for both the transmitting and the receiving.

16. A handheld golf ball locator comprising:

a housing;

a modulator, within the housing and coupled to the signal source, the modulator to modulate a pseudorandom binary sequence (PN) on the signal source using binary phase shift keying (BPSK) modulation to produce a BPSK modulated signal;

a transmitter coupled to the modulator to transmit the BPSK modulated signal in transmitted pulses to locate a golf ball having an RF (radio frequency) circuit, the transmitter being within the housing;

a receiver within the housing, the receiver to receive, as a received signal, a harmonic of the transmitted pulses.

17. A handheld golf ball locator as in claim 16 further comprising:

a frequency source coupled to the transmitter and to the receiver, the frequency source generating the signal source for the modulator and generating a reference frequency for use by the receiver, and wherein the received signal was despread by a ball'"'"'s RF circuit and the harmonic is a 2 times harmonic.

18. A handheld golf ball locator comprising:

a housing having a size of less than about 2,110,000 mm³;

a transmitter in the housing;

a receiver in the housing, wherein a signal isolation between a second harmonic of a transmitted signal from the transmitter and the receiver'"'"'s received signal is greater than about 130 dB.

19. A handheld golf ball locator as in claim 18 wherein the housing has approximate dimensions of less than about 9 inches by 5 inches by 3 inches.

20. A handheld golf ball locator as in claim 18 wherein the signal isolation is greater than about 150 dB.

21. A handheld golf ball locator as in claim 20 further comprising:

a transmitter antenna within the housing and coupled to the transmitter;

a receiver antenna within the housing and coupled to the receiver.

22. A handheld golf ball locator as in claim 20 wherein the receiver antenna is disposed adjacent the transmit antenna which acts as a ground plane at the second harmonic and wherein the receiver antenna receives a signal, at the second harmonic, from a golf ball having an RF circuit.

23. A method of indicating a distance to a golf ball from a handheld golf ball locator, the method comprising:

generating a first set of audio sounds at a first pitch and at a first rate of repetition when at a first distance;

generating a second set of audio sounds at a second pitch and at a second rate of repetition when at a second distance.

24. A method as in claim 23 wherein the first set and the second set of audio sounds are related such that the first distance is larger than the second distance and the first pitch is lower than the second pitch and the first rate is slower than the second rate, and wherein higher pitches and faster rates of repetition indicate shorter distances.

25. A handheld golf ball locator comprising:

a speaker in a housing of the handheld golf ball locator;

a processor coupled to the speaker, the processor generating a first set of audio sounds at a first pitch and at a first rate of repetition when at a first distance relative to a golf ball and the processor generating a second set of audio sounds at a second pitch and at a second rate of repetition when at a second distance relative to the golf ball.

26. A handheld golf ball locator as in claim 25 wherein the first set and the second set of sounds are related such that the first distance is larger than the second distance and the first pitch is lower than the second pitch and the first rate is slower than the second rate, and wherein higher pitches and faster rates of repetition indicate shorter distances.

27. A method of indicating the distance to a golf ball from a handheld golf ball locator, the method comprising:

presenting a first user interface which indicates distance between the handheld golf ball locator and the golf ball and which changes at least at a first rate, with changes in distance, over a first range of a representation of distance;

presenting a second user interface which indicates distance between the handheld golf ball locator and the golf ball and which changes at least at a second rate, with changes in distance, over a second range of the representation of distance.

28. A method as in claim 27 wherein the first user interface comprises at least one of an audio sound and a visual display and the second user interface comprises at least one of an audio sound and a visual display and wherein the representation of distance is a received signal strength indicator or a range determination.

29. A method as in claim 28, the method further comprising:

presenting a third user interface, which indicates distance between the handheld golf ball locator and the golf ball and which changes at least at a third rate, with changes in distance, over a third range of a representation of distance.

30. A method as in claim 29 wherein the first rate is about the same as the third rate and both the first rate and the third rate are greater than zero and the second rate is about zero and wherein the first user interface comprises a plurality of beeps per second at a given distance.

31. A machine readable medium providing executable program instructions which cause a processing system in a handheld golf ball locator to perform a method of indicating the distance to a golf ball from the handheld golf ball locator, the method comprising:

presenting a first user interface which indicates distance between the handheld golf ball locator and the golf ball and which changes at least at a first rate, with changes in distance, over a first range of a representation of distance;

presenting a second user interface which indicates distance between the handheld golf ball locator and the golf ball and which changes at least at a second rate, with changes in distance, over a second range of a representation of distance.

32. A machine readable medium as in claim 31 wherein the first user interface comprises at least one of an audio sound and a visual display and the second user interface comprises at least one of an audio sound and a visual display and wherein the representation of distance is a received signal strength indicator or a range determination.

33. A handheld golf ball locator comprising:

a transmitter to transmit signals to a golf ball having an RF circuit;

a receiver to receive signals from the golf ball;

a user interface indicator to indicate distance between the golf ball and the handheld golf ball locator in response to the signals received from the golf ball;

a processor coupled to the transmitter and to the receiver and the user interface indicator, the processor to present a first user interface which indicates distance between the handheld golf ball locator and the golf ball and which changes at least at a first rate, with changes in distance, over a first range of a representation of distance and the processor to present a second user interface which indicates distance between the handheld golf ball locator and the golf ball and which changes at least at a second rate, with changes in distance, over a second range of a representation of distance.

34. A handheld golf ball locator as in claim 33 further comprising a memory to store a plurality of values which correspond to the first rate and the second rate and wherein the representation of distance is one of a received signal strength indicator or a range determination based on a time of travel of signals between the golf ball and the handheld golf ball locator.

35. A method of locating a stationary golf ball with a handheld golf ball locator, the method comprising:

transmitting, from a transmitter of the handheld golf ball locator, signals at least at different times, each of the different times being within a corresponding time interval and each of the different times being measured relative to a time marker of the corresponding time interval;

processing an output from a receiver of the handheld golf ball locator at each of the different times.

36. A method as in claim 35 wherein the processing does not use the output from the receiver to locate a golf ball at times other than the different times and wherein the processing is synchronized with the transmitting.

37. A method as in claim 35 further comprising:

accumulating a plurality of processed outputs from the receiver, the plurality of processed output being obtained from a corresponding plurality of time intervals;

comparing a representation of accumulated processed outputs to a threshold to determine whether a golf ball is detected and indicating, in response to the comparing, whether a golf ball is detected.

38. A method as in claim 36 wherein the different times are substantially random relative to the time marker which is one of the beginning or the end of a time interval and wherein the transmitter does not transmit at times other than the different times.

39. A method as in claim 36 wherein the different times are separated by time periods which are either different or random, and wherein the transmitter does not transmit at times other than the different times.

40. A method as in claim 36 wherein the different times are separated by time periods which are different and part of a repeating pattern.

41. A method of locating a stationary golf ball with a handheld golf ball locator, the method comprising:

transmitting, from a transmitter of the handheld golf ball locator, signals to be received by an RF circuit of the golf ball;

processing an output from a receiver of the handheld golf ball locator, the processing occurring at times that are separated by time periods between processings, the time periods being either different or random in length.

42. A method as in claim 41 wherein no processing of the output occurs during the time periods.

43. A method as in claim 42 further comprising:

accumulating a plurality of processed outputs from the receiver;

comparing a representation of accumulated processed outputs to a threshold to determine whether a golf ball is detected and indicating, in response to the comparing, whether a golf ball is detected.

44. A method as in claim 41 wherein the transmitting is either at random times or continuous.

45. A handheld golf ball detector comprising:

a housing;

a transmitter in the housing, the transmitter to transmit signals to be received by an RF circuit of a golf ball to be located;

a receiver in the housing;

a processor coupled to the receiver, the processor processing an output of the receiver at times that are separated by non-processing time periods between processings, the non-processing time periods being either different or random in length.

46. A handheld golf ball detector as in claim 45, wherein the processor is coupled to the transmitter to synchronize the transmitter to the processing and to cause the transmitter to transmit at the times that are separated by the non-processing time periods and to not transmit during the non-processing time periods.

47. A handheld golf ball detector as in claim 46 wherein the processor does not use the output from the receiver during the non-processing time periods to locate a golf ball.

48. A handheld golf ball detector as in claim 46 further comprising:

accumulating a plurality of processed outputs from the receiver;

comparing a representation of accumulated processed outputs to a threshold to determine whether a golf ball is detected and indicating, in response to the comparing, whether a golf ball is detected.

49. A handheld golf ball detector as in claim 46 wherein the transmitter transmits, at a first frequency, signals which include a pseudorandom binary sequence modulated therein and wherein the RF circuit in the golf ball returns a signal, at a harmonic of the first frequency, which is received by the receiver.

50. An antenna assembly to locate golf balls, comprising:

a first antenna having a first plane to receive electromagnetic energy at a first frequency, the first antenna having a first boresight substantially perpendicular to the first plane;

a second antenna having a second plane disposed substantially parallel to the first plane, to radiate electromagnetic energy through the first plane at a second frequency, the second antenna having a second boresight substantially perpendicular to the first plane, the second antenna comprising a first ground plane with respect to the first antenna; and

a second ground plane disposed substantially parallel to the second plane, the second antenna disposed between the first antenna and the second ground plane.

51. The antenna assembly of claim 50, wherein the first antenna comprises a planar array antenna and the second antenna comprises a patch antenna.

52. The antenna assembly of claim 51, wherein the first antenna comprises an array of elements comprising at least a first pair of receiving elements to provide a first output signal having a first phase at the first frequency and a second pair of receiving elements to provide a second output signal having a second phase at the first frequency.

53. The antenna assembly of claim 52, further comprising:

means for combining the first output signal in-phase with the second output signal to generate a first receiving antenna pattern having a first beamwidth and a gain node substantially aligned with the first boresight;

means for combining the first output signal out-of-phase with the second output signal to generate a second receiving antenna pattern with a gain null substantially aligned with the first boresight; and

means for subtracting the second receiving antenna pattern from the first receiving antenna pattern to generate a difference pattern, the difference pattern having a second beamwidth substantially narrower than the first beamwidth.

54. The antenna assembly of claim 52, wherein each receiving element comprises a half-wavelength dipole at the first frequency having a voltage distribution with a voltage null at approximately a midpoint of the dipole, the antenna assembly further comprising a conductor disposed substantially perpendicular to the dipole to couple the midpoint of the dipole to the second antenna, the dipole to radiate electromagnetic energy at the second frequency.

55. The antenna assembly of claim 50, wherein the first frequency is a harmonic of the second frequency.

56. The antenna assembly of claim 55, wherein the first frequency is two times the second frequency.

57. The antenna assembly of claim 55, wherein the first frequency is three times the second frequency.

58. The antenna assembly of claim 50, wherein the first frequency is approximately 1830 Mhz, the second frequency is approximately 915 MHz, the gain of the first antenna is in the range of approximately 7 dBi to approximately 14 dBi, and the gain of the second antenna is in the range of approximately 5 dBi to approximately 12 dBi, the antenna assembly occupying a volume less than or equal to approximately 135 cubic centimeters.

59. The antenna assembly of claim 50, wherein the first frequency is approximately 1830 Mhz, the second frequency is approximately 915 MHz, the gain of the first antenna is in the range of approximately 7 dBi to approximately 14 dBi, and the gain of the second antenna is in the range of approximately 5 dBi to approximately 12 dBi, the antenna assembly having dimensions less than or equal to approximately 15 cm by 9 cm by 1 cm.

60. The antenna assembly of claim 58, wherein the first antenna has a front-to-back ratio greater than or equal to approximately 4 dB and the second antenna has a front-to-back ratio greater than or equal to approximately 4 dB.

61. A method for direction-finding in a golf-ball locating system, comprising, at a first range:

transmitting a locating signal at a first frequency from a first antenna having a directional radiation pattern with a maximum radiation intensity in a direction corresponding to a boresight of the first antenna;

receiving a return signal at a second frequency from a target golf ball in a receiving antenna, the receiving antenna having a first directional receiving pattern with a first half-power beamwidth and a maximum receiving sensitivity in a direction corresponding to a boresight of the second antenna; and

at a second range less than the first range

receiving the return signal at the second frequency in the receiving antenna, the receiving antenna having a second directional receiving pattern with a minimum receiving sensitivity in the direction corresponding to the boresight of the second antenna; and

subtracting the second directional receiving pattern from the first directional receiving pattern to obtain a difference receiving pattern, the difference receiving pattern having a second half-power beamwidth less than the first half-power beamwidth.

62. A method for determining a distance between a handheld transceiver and a golf ball, comprising:

modulating a radio frequency carrier at a first carrier frequency with a sinusoidal modulating signal having a first phase to create a first amplitude modulated (AM) carrier signal;

transmitting the first AM carrier signal to a golf ball having a square-law transducer to square the first AM carrier signal;

receiving from the golf ball a second AM carrier signal at a second carrier frequency equal to twice the first carrier frequency, the second AM carrier modulated with the sinusoidal modulation at a second phase; and

comparing the second phase to the first phase to determine a distance between a handheld transceiver and the golf ball.

63. An apparatus for determining a distance between a handheld transceiver and a golf ball, comprising:

a modulator to modulate a radio frequency carrier at a first carrier frequency with a sinusoidal modulating signal having a first phase to create a first amplitude modulated (AM) carrier signal;

a transmitter coupled the modulator to generate the radio frequency carrier and to transmit the first AM carrier signal to a golf ball having a square-law transducer to square the first AM carrier signal;

a receiver to receive from the golf ball a second AM carrier signal at a second carrier frequency equal to twice the first carrier frequency, the second AM carrier modulated with the sinusoidal modulation at a second phase; and

an envelope detector coupled to the receiver to extract the sinusoidal modulation from the second AM carrier signal; and

a phase detector to compare the second phase to the first phase to determine a distance between a handheld transceiver and the golf ball.

70. The method of claim 63, wherein comparing the return signal with the locating signal comprises:

correlating the coded modulation of the return signal with the coded modulation of the locating signal to obtain a correlation coefficient;

applying a time delay to the coded modulation of the locating signal to obtain a maximum of the correlation coefficient;

dithering the time delay to resolve the maximum of the correlation coefficient in time; and

converting the time delay to the distance between the transceiver and the golf ball.

71. The method of claim 70, further comprising dithering the time delay to track the maximum of the correlation coefficient with a change in the distance between the transceiver and the golf ball.

64. A method for locating a golf ball, comprising:

transmitting a locating signal to a golf ball from a transceiver at a first frequency, the locating signal including a coded modulation;

receiving a return signal from the golf ball at the transceiver at a second frequency, different from the first frequency, the return signal including the coded modulation;

comparing the coded modulation of the return signal with the coded modulation of the locating signal to determine a distance between the transceiver and the golf ball.

65. The method of claim 64, wherein the coded modulation comprises a bi-phase code.

66. The method of claim 64, wherein the coded modulation comprises a pseudo noise (PN) code.

67. The method of claim 66, wherein the PN code comprises a maximal length PN code.

68. The method of claim 64, wherein the second frequency is an odd harmonic of the first frequency.

69. The method of claim 68, wherein the second frequency comprises a third harmonic of the first frequency.

72. An apparatus for locating a golf ball, comprising:

a transmitter to transmit a locating signal to a golf ball at a first frequency, the locating signal including a modulation code, the golf ball comprising a harmonic transducer to generate a return signal at a second frequency comprising a harmonic of the first frequency having the modulation code;

a receiver coupled with the transmitter to receive the return signal, to extract the modulation code from the return signal and to correlate the modulation code from the return signal with the modulation code of the locating signal;

a processing device coupled with the transmitter and the receiver, the processing device configured to apply a time delay to the modulation code of the locating signal to obtain a maximum of the correlation coefficient, to dither the time delay to resolve the maximum of the correlation coefficient in time, and to convert the time delay to the distance between the transceiver and the golf ball.

73. The apparatus of claim 72, wherein the processing device is further configured to dither the time delay to track the maximum of the correlation coefficient with a change in the distance between the transceiver and the golf ball.

74. The apparatus of claim 72, wherein the modulation code comprises a bi-phase code.

75. The apparatus of claim 72, wherein the modulation code comprises a pseudo noise (PN) code.

76. The apparatus of claim 75, wherein the PN code comprises a maximal length PN code.

77. The apparatus of claim 72, wherein the second frequency is an odd harmonic of the first frequency.

78. The method of claim 77, wherein the second frequency comprises a third harmonic of the first frequency.

79. An article of manufacture, including machine-accessible instructions that when accessed by a data processing system, cause the data processing system to perform a method, comprising:

transmitting a locating signal to a golf ball from a transceiver at a first frequency, the locating signal including a modulation code;

receiving a return signal from the golf ball at the transceiver at a second frequency, different from the first frequency, the return signal including the modulation code;

comparing the modulation code of the return signal with the modulation code of the locating signal to determine a distance between the transceiver and the golf ball.

80. The article of manufacture of claim 79, wherein the modulation code comprises a bi-phase code.

81. The article of manufacture of claim 79, wherein the modulation code comprises a pseudo noise (PN) code.

82. The article of manufacture of claim 81, wherein the PN code comprises a maximal length PN code.

83. The article of manufacture of claim 79, wherein the second frequency is an odd harmonic of the first frequency.

84. The article of manufacture of claim 83, wherein the second frequency comprises a third harmonic of the first frequency.

85. The article of manufacture of claim 79, wherein comparing the return signal with the locating signal comprises:

correlating the modulation code of the return signal with the modulation code of the locating signal to obtain a correlation coefficient;

applying a time delay to the modulation code of the locating signal to obtain a maximum of the correlation coefficient;

dithering the time delay to resolve the maximum of the correlation coefficient in time; and

converting the time delay to the distance between the transceiver and the golf ball.

86. The article of manufacture of claim 85, further comprising dithering the time delay to track the maximum of the correlation coefficient with a change in the distance between the transceiver and the golf ball.

87. A method for signal isolation in a transceiver in a golf ball locator, comprising:

preventing unintentional contact between signal carrying conductors; and

securing intentional connections between signal carrying conductors with a metallic bonding system.

88. The method of claim 87, wherein the metallic bonding system is one of a uni-metallic bonding system and an alloyed bonding system.

89. A method for stabilizing antenna performance in a golf ball locator, comprising:

providing an indexing feature in an antenna radome; and

using the indexing feature to align an antenna assembly with respect to the antenna radome.

90. A method in a stacked planar antenna array, in a golf ball locator, having a first axis of symmetry in a first direction and a second axis of symmetry in a second direction perpendicular to the first direction, wherein the first axis of symmetry is longer than the second axis of symmetry, comprising:

feeding the stacked planar antenna array along the first axis of symmetry with a first feed cable and a second feed cable; and

maintaining perpendicularity between the first feed cable and the second axis of symmetry and between the second feed cable and the second axis of symmetry.

91. A handheld golf ball locator comprising:

a transmitter coupled to an antenna, the transmitter to transmit a spread spectrum signal to a golf ball;

a receiver coupled to receive a response from the golf ball.

95. A method of initializing a golf ball detector having an RF (radio frequency) transmitter and an RF receiver, the method comprising:

positioning the golf ball detector to receive RF signals from a known source of interference;

initializing the golf ball detector while the positioning occurs.

96. A method as in claim 95 wherein the initializing includes setting a detection threshold based on received RF signals during the initializing, and wherein the RF signals include at least one of (a) reflected RF signals which originated from the transmitter and (b) harmonics of RF signals which originated from the transmitter.