Mobile tracking and positioning system

• US 6,169,497 B1
• Filed: 12/16/1994
• Issued: 01/02/2001
• Est. Priority Date: 04/01/1993
• Status: Expired due to Term

• Current Assignee: Bruno G. Robert
• Original Assignee: Bruno G. Robert
• Inventors: Robert, Bruno
• Primary Examiner(s): SWARTHOUT, BRENT
• Application Number:
  US08/358,792
• Time in Patent Office: 2,209 Days
• Field of Search: 340/988, 340/991, 340/426, 340/539, 340/993, 340/961, 342/450, 342/357, 342/457, 364/449, 701/213, 701/300
• US Class Current: 340/988
• CPC Class Codes: G08G 1/127 to a central station ; Indicators in a central station
• CPC Class Codes: G08G 1/20 Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles

Abstract

A mobile tracking and positioning system includes a plurality of mobile transmit and receive stations that track a mobile target which emits a radio signal in response to the occurrence of a tracking effort initiation event. The tracking stations have a GPS receiver or like means for determining their position, a radio direction finder responsive to the radio signal that determines the vector to the mobile target, a two-way communications system and a computer. The mobile transmit and receive stations exchange their position and direction to target information via the two-way communications systems, enabling the stations to triangulate the location of the target with their computers.

Claims

1. A method of locating a target by triangulation in a region lacking a fixed positioning reference for participating in the triangulation wherein the target includes a transmission unit adapted to broadcast a radio signal in response to an initiation event, said method comprising the steps of:

providing first and second mobile tracking stations that transit the region of the target;

initiating a broadcast of a radio signal from said target in response to the occurrence of said initiation event;

determining the direction of origin of said radio signal relative to said first station;

substantially simultaneously with the determination of the direction of origin of said signal relative to said first station;

a) determining the position of said first station at or above the surface of the earth;

b) transmitting said position and said direction of origin from said first station to said second station;

c) determining the position of said second station;

d) determining the direction of origin of said signal at said second station; and

subsequently triangulating said position of said target at said second station from said positions of said first and second stations and said directions of origin of said radio signal from said target to said first and second stations.

2. The method of claim 1, further comprising the step of:

displaying said position of said target at said second station.

3. The method of claim 1, further comprising the step of:

transmitting said position of said target from said second station to said first station.

4. The method of claim 3, further comprising the step of displaying the location of said target at said first station.

5. The method of claim 1, wherein a third mobile station participates in the tracking and positioning of said target, and wherein said third station determines the direction of origin of said radio signal and the instantaneous position of said third mobile tracking station at or above the surface of the earth and transmits said direction and said instantaneous position to said second station substantially simultaneous with the transmission of direction and position information from said first station to said second station, thereby increasing the accuracy of the tracking and positioning of said target by said second station.

6. The method of claim 1, wherein said target comprises a vehicle and said initiation event comprises unauthorized movement of said vehicle to activate said signal broadcast.

7. The method of claim 1, wherein said initiation event comprises receipt at said target of an initiation signal broadcast by one of said first or second mobile stations.

8. The method of claim 1, wherein said initiation event comprises receipt at said target of an initiation signal broadcast by a remote control unit.

9. The method of claim 1, wherein said target includes a transmission unit for broadcasting said radio signal, said transmission unit responsive to a switch causing initiation of broadcast of said radio signal, wherein said initiation event comprises operation of said switch to cause initiation of broadcast of said radio signal.

10. The method of claim 1, wherein the method further comprises the step of terminating broadcast of said radio signal from said target, said step of terminating comprising the step of broadcasting a termination signal to said target, said target responsively terminating broadcast of said radio signal and entering a power-down mode.

11. A self-contained, portable, mobile tracking and positioning unit for locating a target by triangulation wherein the target broadcasts a radio signal in a region on the surface of the earth which lacks a fixed positioning reference for participating in the triangulation, said positioning unit comprising, in combination:

a positioning determination device for determining the position of said mobile tracking and positioning unit;

a direction finder for determining the direction of origin of said broadcast radio signal;

a two-way communication system for transmitting position information determined from said positioning determination device and direction information determined by said direction finder and for receiving position information and direction information from a remote station; and

a computer for processing said determined position and direction information and said received position information and direction information to locate said target.

12. The mobile tracking and positioning unit of claim 11, wherein said positioning determination device comprises a global positioning system receiver.

13. The mobile tracking and positioning unit of claim 11, wherein said positioning determination device comprises a GLONASS receiver.

14. A method utilizing triangulation for simultaneously tracking a plurality of mobile targets in a region devoid of a fixed positioning reference that participates in the triangulation, said method comprising:

providing a plurality of mobile tracking stations including at least first and second mobile stations adapted to transit said region wherein at least two of said tracking stations cooperatively provide mobile position references for locating a plurality of targets by triangulation,

initiating broadcast of a radio signal from said targets in response to the occurrence of an initiation event at said targets;

determining the direction of origin of said radio signals from each of said plurality of targets relative to said first mobile station;

substantially simultaneously with the determination of the direction origin of said radio signals relative to said first mobile station;

a) determining the instantaneous position of said first mobile station at or above the surface of the earth;

b) transmitting said instantaneous position and said direction of origin from said first mobile station to said second mobile station;

c) determining the instantaneous position of said second mobile station;

d) determining the direction of origin of said radio signals broadcast by said targets at said second mobile station; and

subsequently triangulating said positions of said targets at said second mobile station from said positions of said first and second mobile stations and said respective directions of origin of said radio signals from said targets to said first and second mobile stations.

33. A method as recited in claim 14, wherein said target and said mobile tracking stations are adapted for activation upon receipt of an activation code, said method further comprising:

in said initiating step, broadcasting said radio signal at said target in response to receipt of a first coded activation signal associated with said target to be tracked; and

in said determining steps, performing said determining steps in at least two of said mobile tracking stations in response to receipt of a second coded identification signal containing codes associated with one or more first and second mobile tracking stations designated to participate in the tracking and positioning of said target.

15. A tracking system for locating or tracking a mobile target by triangulation in a region that lacks a fixed participating navigation reference in the vicinity of said target, said system comprising:

first and second mobile tracking stations adapted for transgressing said region in the vicinity of said target and for cooperatively providing instantaneous position references for locating a target by triangulation;

a transmitter disposed at said target for broadcasting a communication signal in response to an initiation event;

said first mobile tracking station further including a position determination unit utilizing a navigation reference external of said region for determining a first instantaneous position indicative of the position of said first mobile tracking station while transiting the vicinity of the target, a bearing determination unit including a receiver for receiving the communication signal from said target and for determining a first target bearing indicative of the relative direction to said target from said first mobile tracking station on the basis of said communication signal, and a transmitter unit for transmitting said first target bearing information and said first instantaneous position of the first tracking station;

said second mobile tracking station further including a receiver for receiving said first target bearing and said first instantaneous position transmitted by said first mobile tracking station, a position determination unit utilizing a navigation reference external of said region for determining a second instantaneous position indicative of the position of said second mobile tracking station while transiting the vicinity of the target, a second bearing determination unit adapted for determining a second target bearing indicative of the relative direction to said target from said second tracking station on the basis of said communication signal transmitted from said target transmitter; and

a processor for analyzing said first and second instantaneous positions of said first and second mobile tracking stations and said first and second target bearings thereby to ascertain by triangulation the exact position of said target.

16. The system of claim 15, wherein at least one of said first and second mobile tracking stations further comprise display means for displaying the position of said target.

17. The system of claim 15, wherein said system further comprises a remote control that broadcasts an initiation signal,

wherein said target further comprises a means for receiving said initiation signal from said remote control and

wherein said tracking and positioning initiation event comprises the transmission of said initiation signal from said remote control to said target causing said target to commence broadcast of said communication signal.

18. The system of claim 15, wherein said target comprises a vehicle, and wherein said tracking and positioning initiation event comprises unauthorized movement of said vehicle to activate said signal broadcast.

19. The system of claim 15, wherein said positioning determination unit of said first mobile tracking station comprises a global positioning system receiver.

20. The system of claim 15, wherein said positioning determination unit of said second mobile tracking station comprises a global positioning system receiver.

21. The system of claim 15, wherein said system further comprises a remote station tracking the position of said first mobile tracking station and a communication system for broadcasting said position to said first mobile tracking station,

wherein the position of said first mobile tracking station is determined by said remote station, and

wherein said position determination unit of said first mobile tracking station comprises means for receiving said broadcast position information.

22. The system of claim 15, wherein said system further comprises a remote station tracking the position of said second mobile tracking station and a communication system for broadcasting said position to said second mobile tracking station,

wherein the position of said second mobile tracking station is determined by said remote station, and

wherein said position determination unit of said second mobile tracking station comprises means for receiving said broadcast position information.

23. The system of claim 15, wherein at least one of said first and second mobile tracking station is airborne.

24. The system of claim 15, wherein said first mobile tracking station further comprises means for broadcasting an initiation signal to said target,

wherein said target further comprises means for receiving said initiation signal from said first mobile tracking station, and

wherein said tracking and positioning initiation event comprises the transmission of said initiation signal from said first mobile tracking station to said target causing said target to commence broadcast of said communication signal.

25. The system of claim 15, wherein said initiation event comprises receipt of an initiation signal broadcast to said target, and wherein said initiation signal comprises:

a first coded activation signal associated with said target to be tracked; and

a second coded identification signal containing codes associated with one or more first and second mobile tracking stations designated to participate in the tracking and positioning of said target;

and wherein said communication signal broadcast by said target comprises a first signal comprising a first identification signal associated with said target and a second identification signal associated with said first and second mobile tracking stations designated to participate in the tracking and positioning of said target.

26. The system of claim 25, wherein said second coded identification signal comprises a general identification signal associated with each of said plurality of first and second mobile tracking stations.

27. A tracking system as recited in claim 15 wherein said first mobile tracking station also ascertains the position of the target, said system further comprising:

a transmitter unit associated with said second mobile tracking station for transmitting said second target bearing and the instantaneous position of the second tracking station to said first mobile tracking station; and

a second receiver associated with said first mobile tracking station for receiving said second target bearing and said instantaneous position transmitted from said second mobile tracking station; and

a second processor responsive to information from the second receiver for analyzing the instantaneous positions first and second mobile tracking stations and first and second target bearings thereby to ascertain by triangulation the exact position of said target.

28. A tracking system as recited in claim 15 wherein said region lies on the surface of the earth.

29. A tracking system as recited in claim 15 further including a switch located at said target for activating said transmitter thereby to produce said initiation event.

30. A tracking system as recited in claim 15 wherein at least one of said first mobile tracking station, said second mobile tracking station and said processor broadcasts a signal for effecting said initiation event.

31. A tracking system as recited in claim 15 wherein said processor is located at said second mobile tracking station.

32. A tracking system as recited in claim 15 wherein said processor is located at a third station.

34. A tracking system for locating or tracking a mobile target by triangulation in a region that lacks a fixed navigation reference in the vicinity of said target for participating in the triangulation, said system comprising:

a) first and second mobile tracking stations adapted for transgressing said region in the vicinity of said target;

b) a transmitter disposed at said target for broadcasting a communication signal in response to an initiation event;

c) said first mobile tracking stations further including a position determination unit utilizing a navigation reference external of said region for determining the instantaneous position of said first mobile tracking station while transiting the vicinity of the target in said region, a bearing determination unit including a receiver for receiving the communication signal from said target and for determining target bearing information indicative of the relative direction to said target from said first mobile tracking station in response to receipt of said communication signal from said target transmitter, and a transmitter unit for transmitting target bearing information and said instantaneous position of the first tracking station;

d) said second mobile tracking station further comprising a position determination unit utilizing a navigation reference external of said region for determining the instantaneous position of said second mobile tracking station while transiting the vicinity of the target in the region, a bearing determination unit for determining target bearing information indicative of the relative direction of said target from said second tracking station in response to receipt of said communication signal from said target transmitter, and a transmitter unit for transmitting said target bearing information and the instantaneous position of said second tracking station; and

e) a processor for analyzing the instantaneous positions of said first and second mobile tracking stations and the bearing information transmitted from said first and second mobile tracking stations thereby to ascertain by triangulation the exact position of said target.

35. A tracking system as recited in claim 34 further including a display device in communication with said processor and being connected with at least one of said first and second mobile tracking stations for indicating the position of said target.

36. A tracking system as recited in claim 34 further including a display device being located at a remote station that communicates with said processor for indicating the position of said target.