SUBSURFACE POSITIONING SYSTEM AND METHOD FOR MONITORING MOVEMENT UNDERGROUND

• US 20110006774A1
• Filed: 05/23/2008
• Published: 01/13/2011
• Est. Priority Date: 05/24/2007
• Status: Active Grant

• Current Assignee: Penguin Automated Systems, Inc.
• Original Assignee: Penguin Automated Systems, Inc.
• Inventors: Baiden, Greg
• Granted Patent: US 8,310,238 B2
• Time in Patent Office: Days
• US Class Current: 324/334
• CPC Class Codes: G01S 11/16 using difference in transit time between electrical and acoustic signals
• CPC Class Codes: G01S 5/0027 of actual mobile position, i.e. position determined on mobile
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G01S 5/26 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/28 takes precedence

Abstract

A system for monitoring movement in a subsurface environment, which may be used to determine flow dynamics within a fluid mass such as an ore body, or track subsurface persons or moving assets. A plurality of underground positioning system (UPS) elements in the subsurface environment transmit characteristic signals to a plurality of antennas, which transmit the signals to a data processing apparatus. The system thus determines changes in the positions of the UPS elements to derive an indication of the motion of the fluid mass or the locations and movement of subsurface persons or assets.

Claims

1. A system for monitoring motion in a subsurface environment, comprising:

at least first, second and third antennas for transmitting electromagnetic radiation (emr) signals from which time of flight data can be derived, each coupled to at least one signal transmitter, the first antenna for transmitting first antenna signals associated with the first antenna, the second antenna for transmitting second antenna signals associated with the second antenna, and the third antenna for transmitting third antenna signals associated with the third antenna;

a plurality of underground positioning system (UPS) elements disposed in spaced relation within the subsurface environment, each UPS element comprising

at least one UPS transmitter for transmitting an emr UPS signal comprising at least an identifier associating the UPS signal with the transmitting UPS element and data relating to signals received from the at least first, second and third antennas; and

at least one UPS receiver for receiving the first antenna signals from the first antenna, the second antenna signals from the second antenna and the third antenna signals from the third antenna; and

a base station antenna coupled to a base receiver and positioned for receiving the UPS signals and transmitting the UPS signals, or signals corresponding to the UPS signals, to a data processing device;

whereby as at least one of the UPS elements moves, the data processing device derives from the UPS signals a direction of movement of the at least one moving UPS element or a rate of movement of the at least one moving UPS element, or both.

2. The system of claim 1 wherein time of flight data is derived at least in part from data provided to the at least first, second and third antennas by an atomic clock.

3. The system of claim 2 wherein the at least one UPS transmitter is capable of retransmitting at least one UPS signal received from others of the plurality of UPS elements, and the UPS receiver is capable of receiving UPS signals from others of the plurality of UPS elements for retransmission, and the base station antenna receives the UPS signals from at least one UPS element.

4. The system of claim 2 wherein each of the first, second and third antennas sequentially transmits a series of signal bursts, and time of flight data is derived at least in part from data identifying a phase shift between successive transmissions.

5. The system of claim 2 wherein the subsurface environment comprises a fluid material and the UPS elements are suspended in the fluid material.

6. The system of claim 2 wherein the UPS elements are affixed to persons or mobile assets.

7. A position monitoring system for monitoring motion in a subsurface environment, comprising:

a plurality of underground positioning system (UPS) elements for suspending within the subsurface environment, each UPS element comprising at least a signal transmitter for transmitting a characteristic emr signal having an identifier for associating the signal with the transmitting UPS element;

a first antenna coupled to a first signal receiver and positioned for receiving the characteristic signals from the UPS elements and transmitting the characteristic signals, or signals corresponding to the characteristic signals, to a data processing apparatus; and

at least a second antenna coupled to the first signal receiver or another signal receiver and positioned for receiving the characteristic signals from the UPS elements and transmitting the characteristic signals, or signals corresponding to the characteristic signals, to the data processing apparatus;

whereby the data processing apparatus receiving the signals from the first antenna and the at least second antenna corresponding to the characteristic signals from the UPS elements determines a location of each transmitting UPS element associated with each characteristic signal as at least one moving UPS elements moves, based on a time of flight defined by a transmit time at which each characteristic signal is transmitted and a receipt time at which each characteristic signal is received by the antennas thereby providing an indication of at least a direction or rate, or both, of the movement of the at least one moving UPS element.

8. The position monitoring system of claim 7, comprising a third antenna coupled to the first signal receiver or another signal receiver, and positioned for receiving the characteristic signals from the UPS elements.

9. The position monitoring system of claim 7, wherein the UPS elements are embedded in a fluid material and the characteristic signals transmitted by the UPS elements entrained in the moving fluid material provide an indication of at least a direction or rate, or both, of movement of the fluid material.

10. The position monitoring system of claim 7 wherein at least some of the plurality of UPS elements further comprise a receiver for receiving signals from the antennas.

11. The position monitoring system of claim 7 wherein at least some of the plurality of UPS elements comprise an acoustic receiver, the system further comprising a plurality of acoustic transmitters for transmitting acoustic signals to the plurality of the UPS elements.

12. The position monitoring system of claim 7 wherein the emr signal is a very low frequency (VLF) signal.

13. The position monitoring system of claim 7 wherein at least some of the plurality of UPS elements are capable of receiving and retransmitting characteristic signals from others of the plurality of UPS elements.

14. For use in a position monitoring system for monitoring motion in a subsurface environment, comprising at least a first antenna coupled to a first signal receiver and positioned for receiving characteristic signals from the UPS elements and transmitting the characteristic signals to a data processing apparatus, an underground positioning system (UPS) element comprising at least:

a housing, and

a signal transmitter contained within the housing, for transmitting a characteristic emr signal having an identifier for associating the signal with the UPS element,

whereby the data processing apparatus receiving the signals from the at least first antenna corresponding to the characteristic signals from the UPS elements determines a location of each UPS element associated with each characteristic signal as at least one moving UPS element moves, based on data from which time of flight data can be derived associated with each characteristic signal received by the at least first antenna, the characteristic signals transmitted by the UPS elements thereby providing an indication of at least a direction or rate, or both, of movement of the at least one moving UPS element.

15. The UPS element of claim 14 wherein the UPS element further comprises an acoustic receiver.

16. The UPS element of claim 14 wherein the emr signal is a very low frequency (VLF) signal.

17. The UPS element of claim 14 wherein the system the UPS element further comprises a receiver for receiving signals from the antennas and an atomic clock for providing data to signals received from the antennas, wherein the system further determines at least a direction or rate, or both, of movement of the at least one moving UPS element, based on the relative time the signals from the antennae are received by the UPS element.

18. The UPS element of claim 14 wherein the UPS element is capable of receiving and retransmitting characteristic signals from others of the plurality of UPS elements.

19. A method for monitoring motion in a subsurface environment, comprising the steps of:

a. locating a plurality of underground positioning system (UPS) elements within the subsurface environment, each UPS element comprising at least a signal transmitter for transmitting a characteristic emr signal having an identifier for associating the characteristic signal with the transmitting UPS element;

b. receiving the emr signals from the plurality of UPS elements at a first position in communication with the UPS elements, and transmitting data to a data processing apparatus corresponding to a time of receiving each emr signal at the first position;

c. receiving the emr signals from the plurality of UPS elements at least at a second position in communication with the UPS elements, and transmitting data to the data processing apparatus corresponding to a time of receiving each emr signal at the second position; and

d. processing the data to determine at least a direction or rate, or both, of movement of at least one moving UPS element.

20. The method of claim 19, comprising before step d. the step of receiving the emr signals from the plurality of UPS elements at least at a third position in communication with the UPS elements, and transmitting data to the data processing apparatus corresponding to a time of receiving each emr signal at the third position.

21. The method of claim 19 wherein comprising, before step d., the steps of the UPS elements receiving antenna signals from a signal source in communication with the UPS elements and transmitting data corresponding to a time of receiving each antenna signal at each UPS element.

22. The method of claim 21 wherein the antenna signal is a very low frequency (VLF) signal.

23. The method of claim 19 wherein the emr signals from the UPS elements are very low frequency (VLF) signals.

24. The method of claim 19 comprising, before step d., the further step of at least some of the UPS elements transmitting data to other UPS elements for retransmission by at least one of the other UPS elements to the data processing apparatus.