System and method for positioning in configured environments

• US 7,916,074 B2
• Filed: 02/17/2009
• Issued: 03/29/2011
• Est. Priority Date: 04/28/2006
• Status: Expired due to Fees

• Current Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Original Assignee: Loctronix Corp. (Comtech Telecommunications Corporation)
• Inventors: Mathews, Michael B., Gold, Kenn L., MacDoran, Peter F.
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Mull; Fred H
• Application Number:
  US12/372,235
• Publication Number:
  US 20090256750A1
• Time in Patent Office: 770 Days
• Field of Search: 34235701-358, 342/450, 342463-465
• US Class Current: 342/357.48
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks

Abstract

The present invention relates to a system and method for providing location determination in a configured environment in which Global Navigation Satellite System Signals may not be available. In this regard, local beacon systems generate spread spectrum CDMA signals that are received by spectral compression units that derive physically meaningful observations without a requirement for correlation of the intercepted energy by means of the known spreading codes. The invention can coexist with communication assets already in place, and the design allows for self calibration, which simplifies installation and usage. The invention has utility in applications in which GNSS signals are unavailable or limited, for example, in warehouse inventory management, in search and rescue operations and in asset tracking in indoor environments.

Claims

1. A system for providing physical state information, comprising:

at least one emitter that emits a structured energy emission within a transmission medium, wherein the structured energy emission has identifying characteristics associating the emission with the emitter that are—

independent of the emitter dynamics;

at least one interceptor that receives the structured energy emission propagated through a transmission medium from the at least one emitter, wherein the interceptor is configured to

process the received emissions using spectral compression utilizing a non-linear operation to produce a set of observables suitable for physical state estimation, wherein the set of observables is a function of the identifying characteristics associating the set of observables with the at least one emitter; and

communicate the set of observables to a physical state estimator, wherein the physical state estimator is configured to determine at least one member of a relative physical state between the interceptor and emitter.

2. The system of claim 1, wherein the transmission medium is comprised of at least one of a free space, gas and a weak plasma.

3. The system of claim 1, wherein the transmission medium is comprised of solid material.

4. The system of claim 1, wherein the transmission medium is comprised of a liquid.

5. The system of claim 1, wherein the structured energy emission comprises a positioning and navigation signal.

6. The system of claim 1, wherein the structured energy emission comprises a communications signal.

7. The system of claim 1, wherein the emitter is explicitly deployed for the purpose of physical state estimation.

8. The system of claim 1, wherein spectral compression comprises extracting at least one known physical characteristic of the energy emission from the emitter.

9. The system of claim 8, wherein the extraction of at least one known physical characteristic of the energy emission from the emitter occurs without regard to modulated information content of the energy emission.

10. The system of claim 1, wherein the set of observables produced using spectral compression includes at least one of physical characteristics in the form of amplitude, phase and temporal derivatives of the intercepted energy as it propagates through a transmission medium without regard to the preservation of information content modulated within the energy emissions.

11. The system of claim 1, wherein the physical state estimator is configured to

reference stored configuration data;

and

use the referenced stored configuration data in determining the at least one member of the relative physical state between the interceptor and emitter based on the set of observables received from the interceptor.

12. The system of claim 1, wherein:

the identifying characteristics that associate the emitter with the structured energy emission includes a frequency characteristic; and

the set of observables produced from the received structured energy emission using spectral compression includes a frequency characteristic that associates the emitter with the emission.

13. The system of claim 1, wherein:

the identifying characteristics that associate the emitter with the structured energy emission includes a timing characteristic; and

the set of observables produced from the received structured energy emission using spectral compression includes a timing characteristic that associates the emitter with the emission.

14. The system of claim 1, wherein:

the identifying characteristics that associate the emitter with the structured energy emission includes an amplitude characteristic; and

the set of observables produced from the received structured energy emission using spectral compression includes an amplitude characteristic that associates the emitter with the emission.

15. A method for providing physical state information, comprising:

intercepting a structured energy emission from at least one emitter through a propagation medium at least one interceptor, wherein the structured energy emission has identifying characteristics associating the emission with the emitter that are independent of the emitter dynamics;

processing the received energy emission using spectral compression utilizing a non-linear operation to produce a set of observables associated with the emission, wherein the set of observables is a function of the identifying characteristics associating the set of observables with the at least one emitter;

receiving configuration data pertaining to the identifying characteristics and physical configuration of at least one of the emitter and interceptor; and

determining at least one member of a relative physical state between the interceptor and emitter based on the set of observables and the configuration data.

16. The method of claim 15, wherein processing the received energy emission using spectral compression to produce a set of observables associated with the emission is performed by squaring the energy emission recovering second harmonic amplitude, frequency and phase of the suppressed carrier.

17. The method of claim 15, wherein processing the received energy emission using spectral compression to produce a set of observables associated with the emission is performed by delay and multiply recovery of the characteristics comprising frequency, amplitude and phase of at least one periodic modulation defined over an interval of time within the energy emission.

18. The method of claim 15, wherein

a plurality of emissions from the at least one emitter are intercepted at the at least one interceptor;

and

processing the plurality of received energy emissions is performed by bandwidth synthesis where the plurality of energy emissions are multiplied together to produce the set of observables associated with the plurality of emissions.

19. The method of claim 15, wherein processing the received energy emission using spectral compression to produce a set of observables associated with the emission uses differentiation to recover the frequency, amplitude, and phase of any periodic modulations over a defined interval of time.

20. The method of claim 15, wherein

the energy emission from an emitter is intercepted by first and second interceptors;

and

spectral compression utilizes a non-linear operation and cross-correlation of the emissions intercepted by the first and second interceptors to produce a set of observables associated with the emission.

21. The method of claim 15, wherein the set of observables produced using spectral compression includes at least one of the identifying characteristics as a function of amplitude, phase, time and temporal derivatives of the intercepted emission as it propagates through a transmission medium without regard to the preservation of information content modulated within the energy emission.

22. The method of claim 15, wherein determining the relative physical state of the emitter using the set of observables and configuration data comprises:

estimating the physical state of at least one of the emitter and the interceptor relative to a designated reference point; and

calibrating the physical state of the reference point relative to a configured environment using the configuration data.

23. The method of claim 15, further comprising:

estimating the physical state of at least one of the emitter and the interceptor relative to a designated reference point; and

updating configuration data pertaining to the identifying characteristics and physical configuration of at least one of the emitter and interceptor.

24. The method of claim 15, wherein within a configured environment

at least one of the emitter or interceptor is designated as a reference point wherein at least one member of the physical state of the reference point is predetermined;

and

at least one of the emitter or interceptor is designated a physical state sensor wherein the physical state of the physical state sensor is determined relative to the physical state of the reference point.

25. The method of claim 24, wherein

the physical state sensor is designated as a second reference point;

and

at least one of the emitter or interceptor is designated a second physical state sensor wherein the physical state of the second physical state sensor is determined relative to the physical state of the second reference point.

26. The method of claim 24, where the physical state of the reference point is calibrated relative to an external reference such that the physical state of the physical state sensor can be estimated relative to an external reference frame.

27. The method of claim 24, where a plurality of reference points are assigned to a zone such that the relative physical states of all reference points in the zone are calibrated with respect to each other.

28. A system for providing improved interception of energy emissions for use in deriving physical state information, comprising:

at least one emitter that emits energy within a transmission medium;

at least one interceptor that receives energy propagated through a transmission medium from the at least one emitter, wherein the interceptor is configured to

process a received energy emission using spectral compression utilizing a non-linear operation to produce a first set of observables about the emission;

modify the at least one interceptor based on the set of observables about the emission;

process at least one of the first or a second received energy emission to produce a second set of observables suitable for physical state estimation; and

communicate at least one of the first or second set of observables to a physical state estimator;

wherein the physical state estimator is configured to determine at least one member of the relative physical state between the interceptor and emitter based on at least one of the first or second set of observables received from the at least one interceptor.

29. The system of claim 28, wherein the interceptor is configured to be modified based on the first set of observables by calibrating the system clock state to narrow post detection bandwidth.

30. The system of claim 28, wherein spectral compression utilizing a non-linear operation includes determining the system clock state to minimize code-correlation searching of time and frequency domains.

31. A method for providing improved interception of energy emissions for use in deriving physical state information, comprising:

intercepting at least one interceptor energy propagated through a transmission medium from at least one emitter;

processing a received energy emission using spectral compression utilizing a non-linear operation to produce a first set of observables about the emission;

modifying the interceptor based on the set of observables about the received emission;

processing at least one of the first or a second received energy emission to produce a second set of observables suitable for physical state estimation;

communicating at least one of the first or second set of observables to a physical state estimator, wherein the physical state estimator is configured to determine at least one member of the relative physical state between the interceptor and emitter based on at least one of the first or second set of observables received from the at least one interceptor.

32. The method of claim 31, wherein the interceptor is configured to be modified based on the first set of observables by calibrating the system clock state to narrow post detection bandwidth.

33. The system of claim 32, wherein spectral compression utilizing a non-linear operation includes determining the system clock state to minimize code-correlation searching of time and frequency domains.

34. A system for providing physical state information, comprising:

a plurality of emitters within a transmission medium that emit at least two structured emissions with incompatible intrinsic characteristics;

at least one interceptor configured to

process the at least two structured emissions with incompatible intrinsic characteristics using spectral compression utilizing a non-linear operation to produce a set of observables suitable for physical state estimation, wherein the set of observables is a function of the intrinsic characteristics of the source emitters;

communicate the set of observables to a physical state estimator; and

wherein the physical state estimator is configured to determine at least one member of a relative physical state between the interceptor and plurality of emitters based on the set of observables received from the at least one interceptor.

35. The system of claim 34, wherein the at least two structured emissions with incompatible intrinsic characteristics are from the group consisting of communication signals, television signals, GNSS signals, autonomous beacon signals and acoustic signals.

36. A method for providing physical state information, comprising:

intercepting at an interceptor at least two structured emissions with incompatible intrinsic characteristics from a plurality of emitters;

processing the at least two structured emissions with incompatible intrinsic characteristics at the interceptor using spectral compression utilizing a non-linear operation to produce a set of observables suitable for physical state estimation, wherein the set of observables is a function of the intrinsic characteristics of the source emitters; and

communicating the set of observables to a physical state estimator, wherein the physical state estimator configured to determine at least one member of a relative physical state between the interceptor and plurality of emitters based on the set of observables received from the interceptor.

37. The method of claim 36, wherein the at least two structured emissions with incompatible intrinsic characteristics are from the group consisting of communication signals, television signals, GNSS signals, autonomous beacon signals and acoustic signals.