Navigational device for a scuba diver

• US 5,570,323 A
• Filed: 01/19/1995
• Issued: 10/29/1996
• Est. Priority Date: 01/19/1995
• Status: Expired due to Fees

• Current Assignee: Ascend Marine, Inc.
• Original Assignee: Ascend Corporation
• Inventors: Guthrie, Joe C., Prichard, D. Wayne
• Primary Examiner(s): ELDRED, JOHN W
• Application Number:
  US08/375,354
• Time in Patent Office: 649 Days
• Field of Search: 367/2, 367/131, 367/118, 367/910
• US Class Current: 367/118
• CPC Class Codes: G01S 15/10 using transmission of interrupted, pulse-modulated waves determination of distance by phase measurement G01S15/32
• CPC Class Codes: G01S 15/74 Systems using reradiation of acoustic waves, e.g. IFF, i.e. identification of friend or foe
• CPC Class Codes: G01S 3/803 using amplitude comparison of signals derived from receiving transducers or transducer systems having differently-oriented directivity characteristics
• CPC Class Codes: Y10S 367/91 Portable sonar devices

Abstract

A navigational device (10) for assisting a scuba diver in determining a direction toward and a distance from a dive boat (12) or to a buoy near the shore at which point the dive originated. The navigational device (10) includes a transponder unit (16) carried by a boat (12) and an interrogator unit (34) carried by a diver. The interrogator unit (34) includes at least one transducer (68) positioned for detecting signals from the transponder unit (16). Direction and distance indicators (46,50) are carried on the surface of the interrogator unit (34) for visual indication to the diver. The transponder unit (16) repeatedly pulses an identification signal to be received by the interrogator unit (34). When a valid identification signal is received by the interrogator unit (34), the direction from which the signal was received is determined and displayed. When the distance to the boat (12) is required, a signal is emitted from the interrogator unit (34). Upon receipt of the distance request signal, the transponder unit (16) emits a distance response pulse. The distance between the diver and the boat (12) is then determined by the interrogator unit (34) as a function of the time elapsed between the emission of the distance request signal and the receipt of the distance response pulse.

Claims

1. A navigational device for assisting a scuba diver in determining a direction toward and a distance from a selected point, said navigational device comprising:

a transponder unit disposed at said selected point for broadcasting an identification signal and a distance response pulse and for receiving a distance request signal, said identification signal and said distance response pulse being coded to include a transponder message signal and a transponder unit identification signal to indicate a particular said transponder unit, said transponder unit including a transponder encoder for converting said identification signal and said distance response pulse from digital to analog domain and a transponder decoder for converting said distance request signal from analog to digital domain; and

an interrogator unit for receiving said identification signal and said distance response pulse, said distance request signal being coded to include an interrogator message signal and an interrogator unit identification signal to indicate a particular said interrogator unit, for transmitting said distance request signal, and for determining at least a direction to said transponder unit, said interrogator unit including an interrogator decoder for converting said identification signal and said distance response pulse from analog to digital domain and an interrogator encoder for converting said distance request signal from digital to analog domain, said transponder unit producing said distance response pulse in response to receipt of said distance request signal, said interrogator unit determining a distance to said transponder unit as a function of time elapsed between transmitting said distance request signal and receipt of said distance response pulse.

2. The navigational device of claim 1 wherein said transponder unit includes at least:

a user interface fur controlling operation of said transponder unit;

a transponder central processing unit for producing said identification signal and said distance response pulse and for attaching said transponder unit identification signal to said identification signal and said distance response pulse, said transponder central processing unit being further provided for processing incoming signals to detect said interrogator unit identification signal, said transponder central processing unit rejecting said incoming signal wherein said interrogator unit identification signal is not identical to said transponder unit identification signal and processing said incoming signals received by said transponder unit wherein said interrogator unit identification signal is identical to said transponder unit identification signal;

a transmitter for amplifying said identification signal and said distance response pulse;

a transducer for broadcasting said identification signal and said distance response pulse; and

a receiver for receiving at least said distance request signal.

3. The navigational device of claim 2 wherein said transponder unit further includes a display for monitoring functions of said transponder unit.

4. The navigational device of claim 1 wherein said interrogator unit includes at least:

a display for visually indicating a direction and a distance to said transponder unit;

at least one transducer for receiving said identification signal and said distance response pulse and for emitting said distance request signal;

a receiver for receiving said identification signal and said distance response pulse;

an interrogator central processing unit for processing said identification signal and said distance response pulse to detect said transponder unit identification signal, said interrogator central processing unit rejecting said identification signal and said distance response pulse wherein said transponder unit identification signal is not identical to said interrogator unit identification signal and for processing said identification signal and said distance response pulse wherein said transponder unit identification signal is identical to said interrogator unit identification signal in order to determine a direction toward and a distance to said transponder unit, and further for producing said distance request signal, said interrogator central processing unit attaching said interrogator unit identification signal to said distance request signal; and

a transmitter for amplifying said distance request signal.

5. The navigational device of claim 4 wherein said at least one transducer includes a left transducer, a center transducer and a right transducer, at least said center transducer defining a narrow-beam transducer for emitting said distance request signal and for receiving said distance response pulse.

6. The navigational device of claim 5 wherein said left transducer and said right transducer each define broad-beam transducers for receiving said identification signal.

7. A navigational device for assisting a scuba diver in determining a direction toward and a distance from a selected point, said navigational device comprising:

a transponder unit disposed at said selected point for broadcasting an identification signal and a distance response pulse and for receiving a distance request signal, said identification signal and said distance response pulse being coded to include a transponder message signal and a transponder unit identification signal to indicate a particular said transponder unit, said transponder unit including at least;

a transponder encoder for converting said identification signal and said distance response pulse from digital to analog domain;

a transponder decoder for converting said distance request signal from analog to digital domain;

a user interface for controlling operation of said transponder unit;

a transponder central processing unit for producing said identification signal and said distance response pulse and for attaching said transponder unit identification signal to said identification signal and said distance response pulse, said transponder central processing unit being further provided for processing incoming signals to detect said interrogator unit identification signal, said transponder central processing unit rejecting said incoming signals wherein said interrogator unit identification signal is not identical to said transponder unit identification signal and processing said incoming signals received by said transponder unit wherein said interrogator unit identification signal is identical to said transponder unit identification signal;

a transmitter for amplifying said identification signal and said distance response pulse;

a transducer for broadcasting said identification signal and said distance response pulse; and

a receiver for receiving at least said distance request signal, and

an interrogator unit for receiving said identification signal and said distance response pulse, for transmitting said distance request signal, said distance request signal being coded to include an interrogator message signal and an interrogator unit identification signal to indicate a particular said interrogator unit, and for determining at least a direction to said transponder unit said distance request signal being received by said transponder unit, said transponder unit producing said distance response pulse in response to receipt of said distance request signal, said interrogator unit receiving said distance response pulse and determining a distance to said transponder unit as a function of time elapsed between transmitting said distance request signal and receipt of said distance response pulse, said interrogator unit including at least;

an interrogator decoder for converting said identification signal and said distance response pulse from analog to digital domain;

an interrogator encoder for converting said distance request signal from digital to analog domain;

a display for visually indicating a direction and a distance to said transponder unit;

at least one transducer for receiving said identification signal and said distance response pulse and for emitting said distance request signal;

a receiver for receiving said identification signal and said distance response pulse;

an interrogator central processing unit for processing said identification signal and said distance response pulse to detect said transponder unit identification signal, said interrogator central processing unit rejecting said identification signal and said distance response pulse wherein said transponder unit identification signal is not identical to said interrogator unit identification signal and for processing said identification signal and said distance response pulse wherein said transponder unit identification signal is identical to said interrogator unit identification signal in order to determine a direction toward and a distance to said transponder unit, and further for producing said distance request signal, said interrogator central processing unit attaching said interrogator unit identification signal to said distance request signal; and

a transmitter for amplifying said distance request signal.

8. The navigational device of claim 7 wherein said transponder unit further includes a display for monitoring functions of said transponder unit.

9. The navigational device of claim 7 wherein said at least one transducer includes a left transducer, a center transducer and a right transducer, at least said center transducer defining a narrow-beam transducer for emitting said distance request signal and for receiving said distance response pulse.

10. The navigational device of claim 9 wherein said left transducer and said right transducer each define broad-beam transducers for receiving said identification signal.

11. A navigational device for assisting a scuba diver in determining a direction toward and a distance from a selected point, said navigational device comprising:

a transponder unit for broadcasting an identification signal and a distance response pulse and for receiving a distance request signal, said identification signal and said distance response pulse being coded to include a transponder message signal and a transponder unit identification signal to indicate a particular said transponder unit, said transponder unit including at least;

a user interface for controlling operation of said transponder unit,

a transponder central processing unit for producing said identification signal and said distance response pulse and for attaching said transponder unit identification signal to said identification signal and said distance response pulse, said transponder central processing unit being further provided for processing incoming signals to detect said interrogator unit identification signal, said transponder central processing unit rejecting said incoming signals wherein said interrogator unit identification signal is not identical to said transponder unit identification signal and processing said incoming signals received by said transponder unit wherein said interrogator unit identification signal is identical to said transponder unit identification signal;

a transmitter for amplifying said identification signal and said distance response pulse;

a transducer for broadcasting said identification signal and said distance response pulse;

a receiver for receiving at least said distance request signal;

a transponder encoder for converting said identification signal and said distance response pulse from digital to analog domain; and

a transponder decoder for converting said distance request signal from analog to digital domain; and

an interrogator unit for receiving said identification signal for determining at least a direction to said transponder unit and for transmitting said distance request signal, said distance request signal being coded to include an interrogator message signal and an interrogator unit identification signal to indicate a particular said interrogator unit, said distance request signal being received by said transponder unit, said transponder unit producing a distance response pulse in response to receipt of said distance request signal, said interrogator unit receiving said distance response pulse and determining a distance to said transponder unit as a function of time elapsed between transmitting said distance request signal and receipt of said distance response pulse, said interrogator unit including at least;

a display for visually indicating a direction and a distance to said transponder unit;

at least one transducer for receiving said identification signal and said distance response pulse and for emitting said distance request signal;

a receiver for receiving said identification signal and said distance response pulse;

an interrogator central processing unit for processing said identification signal and said distance response pulse to detect said transponder unit identification signal, said interrogator central processing unit rejecting said identification signal and said distance response pulse wherein said transponder unit identification signal is not identical to said interrogator unit identification signal and for processing said identification signal and said distance response pulse wherein said transponder unit identification signal is identical to said interrogator unit identification signal in order to determine a direction toward and a distance to said transponder unit, and further for producing said distance request signal, said interrogator central processing unit attaching said interrogator unit identification signal to said distance request signal;

a transmitter for amplifying said distance request signal;

an interrogator decoder for converting said identification signal and said distance response pulse from analog to digital domain; and

an interrogator encoder for converting said distance request signal from digital to analog domain.

12. The navigational device of claim 11 wherein said transponder unit further includes a display for monitoring functions of said transponder unit.

13. The navigational device of claim 11 wherein said at least one transducer includes a left transducer, a center transducer and a right transducer, at least said center transducer defining a narrow-beam transducer for emitting said distance request signal and for receiving said distance response pulse.

14. The navigational device of claim 13 wherein said left transducer and said right transducer each define broad-beam transducers for receiving said identification signal.