Efficient localization of transmitters within complex electromagnetic environments

• US 9,551,781 B2
• Filed: 10/30/2015
• Issued: 01/24/2017
• Est. Priority Date: 10/30/2014
• Status: Active Grant

• Current Assignee: Bastille Networks, Inc.
• Original Assignee: Bastille Networks, Inc.
• Inventors: Baxley, Robert John, Altman, Justin Trent
• Primary Examiner(s): Nguyen, Hai V
• Application Number:
  US14/928,974
• Publication Number:
  US 20160127931A1
• Time in Patent Office: 452 Days
• Field of Search: 455/67.16, 455/456.1
• US Class Current: 1/1
• CPC Class Codes: G01S 2205/01 specially adapted for specific applications
• CPC Class Codes: G06F 16/285 Clustering or classification
• CPC Class Codes: G06F 16/951 Indexing; Web crawling techniques
• CPC Class Codes: G06T 7/20 Analysis of motion motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes
• CPC Class Codes: G06V 20/41 Higher-level, semantic clustering, classification or understanding of video scenes, e.g. detection, labelling or Markovian modelling of sport events or news items segmenting video sequences G06V20/49
• CPC Class Codes: G06V 20/46 Extracting features or characteristics from the video content, e.g. video fingerprints, representative shots or key frames
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69
• CPC Class Codes: G06V 2201/10 Recognition assisted with metadata
• CPC Class Codes: G08B 13/00 Burglar, theft or intruder alarms
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04B 17/10 of transmitters
• CPC Class Codes: H04B 17/391 Modelling the propagation channel
• CPC Class Codes: H04K 2203/16 for telephony
• CPC Class Codes: H04K 2203/18 for wireless local area networks or WLAN
• CPC Class Codes: H04K 3/22 including jamming detection and monitoring
• CPC Class Codes: H04L 63/1416 Event detection, e.g. attack signature detection
• CPC Class Codes: H04L 63/1425 Traffic logging, e.g. anomaly detection
• CPC Class Codes: H04L 63/302 gathering intelligence information for situation awareness or reconnaissance
• CPC Class Codes: H04N 5/265 Mixing
• CPC Class Codes: H04W 12/08 : Access security
• CPC Class Codes: H04W 12/10 : Integrity
• CPC Class Codes: H04W 12/12 : Detection or prevention of fraud
• CPC Class Codes: H04W 12/122 : Counter-measures against attacks; Protection against rogue devices
• CPC Class Codes: H04W 12/63 : Location-dependent; Proximity-dependent
• CPC Class Codes: H04W 12/64 : using geofenced areas
• CPC Class Codes: H04W 12/79 : Radio fingerprint
• CPC Class Codes: H04W 24/08 : Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 4/021 : Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
• CPC Class Codes: H04W 4/70 : Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 84/18 : Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

Systems and methods can support determining a physical position of a radio transmitter. A physical model for electromagnetic signal propagation within the electromagnetic environment may be established. Radio frequency signal power levels associated with the radio transmitter may be received from one or more radio frequency sensors. Parameters associated with the physical model may be estimated for one or more test locations within the electromagnetic environment. An error metric between the received radio frequency signal power levels and the physical model may be computed for the one or more test locations. Bounds on the parameters associated with the physical model may be established to prune away physically impossible solutions. The parameters associated with the physical model may be optimized across the one or more test locations to establish a preferred location estimate for the radio transmitter.

Claims

1. A method for determining a physical position of a radio transmitter, comprising:

establishing a physical model for electromagnetic signal propagation within the electromagnetic environment;

receiving radio frequency signal power levels associated with the radio transmitter from one or more radio frequency sensors;

estimating parameters associated with the physical model for one or more test locations within the electromagnetic environment;

computing an error metric between the received radio frequency signal power levels and the physical model for the one or more test locations;

establish bounds on the parameters associated with the physical model to prune away physically impossible solutions; and

optimizing the parameters associated with the physical model across the one or more test locations to establish a preferred location estimate for the radio transmitter.

2. The method of claim 1, wherein the one or more test locations comprise a search grid throughout the electromagnetic environment.

3. The method of claim 1, wherein the radio frequency signal power levels are a substantially linear function of the parameters associated with the physical model.

4. The method of claim 1, wherein optimizing the parameters associated with the physical model is simplified by applying a pseudoinverse.

5. The method of claim 1, wherein establishing a preferred location estimate is improved by operating on signals from selected subsets of the one or more radio frequency sensors.

6. The method of claim 1, wherein the physical model for electromagnetic signal propagation comprises addition details of obstructions within the electromagnetic environment.

7. The method of claim 1, wherein the received radio frequency signal power levels are clustered into groups prior to localization.

8. The method of claim 1, further comprising tracking motion associated with the radio transmitter using a Kalman filter.

9. The method of claim 1, further comprising tracking motion associated with the radio transmitter using a particle filter.

10. The method of claim 1, further comprising incorporating angulation data associated with the one or more radio frequency sensors.

11. A system for determining a physical position of a radio transmitter, comprising:

one or more sensor antennas;

one or more radio frequency sensors configured to couple radio frequency signals from the one or more sensor antennas and generate data samples representing at least a portion of the radio frequency signals; and

a signal analysis engine comprising one or more processing units, and one or more processing modules configuring the one or more processing units to;

establish a physical model for electromagnetic signal propagation within the electromagnetic environment;

receive radio frequency signal power levels associated with the radio transmitter from one or more radio frequency sensors;

estimate parameters associated with the physical model for one or more test locations within the electromagnetic environment;

compute an error metric between the received radio frequency signal power levels and the physical model for the one or more test locations;

establish bounds on the parameters associated with the physical model to prune away physically impossible solutions; and

optimize the parameters associated with the physical model across the one or more test locations to establish a preferred location estimate for the radio transmitter.

12. The system of claim 11, wherein the one or more test locations comprise a search grid throughout the electromagnetic environment.

13. The system of claim 11, wherein the radio frequency signal power levels are a substantially linear function of the parameters associated with the physical model.

14. The system of claim 11, wherein optimizing the parameters associated with the physical model is simplified by applying a pseudoinverse.

15. The system of claim 11, wherein establishing a preferred location estimate is improved by operating on signals from selected subsets of the one or more radio frequency sensors.

16. The system of claim 11, wherein the physical model for electromagnetic signal propagation comprises addition details of reflections and multipath propagation.

17. The system of claim 11, wherein the received radio frequency signal power levels are clustered into groups prior to localization.

18. The system of claim 11, wherein the one or more processing units are further configured to track motion associated with the radio transmitter using a Kalman filter.

19. The system of claim 11, wherein the one or more processing units are further configured to track motion associated with the radio transmitter using a particle filter.

20. A system for determining a physical position of a radio transmitter, comprising:

one or more radio frequency sensor antennas within the electromagnetic environment;

one or more operator interfaces for communicating information associated with wireless devices; and

a signal analysis engine comprising one or more processing units, and one or more processing modules configuring the one or more processing units to;

establish a physical model for electromagnetic signal propagation within the electromagnetic environment;

receive radio frequency signal power levels associated with the radio transmitter from one or more radio frequency sensor antennas;

estimate parameters associated with the physical model for one or more test locations comprising a search grid spanning the electromagnetic environment;

compute an error metric between the received radio frequency signal power levels and the physical model for the one or more test locations;

establish bounds on the parameters associated with the physical model to prune away physically impossible solutions; and

optimize the parameters associated with the physical model across the one or more test locations by applying a pseudoinverse to establish a preferred location estimate for the radio transmitter; and

present the preferred location estimate for the radio transmitter to the one or more operator interfaces.