Method and system for computing and displaying location information from cross-correlation data

• US 20060250264A1
• Filed: 04/25/2005
• Published: 11/09/2006
• Est. Priority Date: 04/25/2005
• Status: Active Grant

• Current Assignee: Keysight Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Cutler, Robert T., Ii, Mutsuya
• Granted Patent: US 7,869,810 B2
• Time in Patent Office: Days
• US Class Current: 340/657
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/02527 Detecting or resolving anomalies in the radio frequency fingerprints of the radio-map
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence

Abstract

Two or more receivers in a plurality of receivers are selected and the signal data from each receiver obtained. A cross-correlation of signal data is computed for each receiver paring in the selected receivers. The results of each cross-correlation are then combined and mapped into a graphical indicator function. The graphical indicator function generates a visual representation of location information using the results of each cross-correlation computation. The visual representation is then displayed to a user. Additional location information may also be simultaneously displayed with the visual representation or upon command.

Claims

1. A method for displaying location information from cross-correlation data for a plurality of compute locations, comprising:

obtaining signal data from two or more receivers;

for each possible pairing of receivers, computing the cross-correlation data between the signal data received from each receiver in a pair of receivers;

computing the expected time difference of arrival (TDOA) values for each selected receiver pairing;

for each selected receiver pairing, combining the cross-correlation data at the time offsets indicated by the respective TDOA values; and

mapping the combined cross-correlation data into a graphical indicator function.

2. The method of claim 1, further comprising displaying a result of the graphical indicator function in an image.

3. The method of claim 1, further comprising selecting one or more receiver pairings to exclude from the computation of expected time difference of arrival (TDOA) values.

4. The method of claim 1, further comprising changing how the cross-correlation data at the time offsets indicated by the respective TDOA values are combined.

5. The method of claim 4, further comprising changing how the combined cross-correlation data are mapped into the graphical indicator function.

6. The method of claim 1, wherein mapping the combined cross-correlation data into a graphical indicator function comprises mapping the combined cross-correlation data into one or more colors, where each color represents a portion of the cross-correlation data.

7. The method of claim 6, wherein mapping the combined cross-correlation data into one or more colors comprises mapping the combined cross-correlation data into one or more colors that indicate a range of values.

8. The method of claim 7, wherein a range of values representing the top range of values is mapped into a first color and a second contrasting color, where the second contrasting color represents a top range of values.

9. The method of claim 1, wherein mapping the combined cross-correlation data into one or more colors comprises mapping the combined cross-correlation data into contour lines.

10. The method of claim 2, further comprising:

selecting a location in the image; and

displaying additional information associated with one or more receivers.

11. The method of claim 10, wherein the additional information associated with one or more receivers comprises one of a location of each receiver, one or more hyperbolic lines, a computed TDOA for each receiver pairing, a spectrum waveform for each receiver, and a cross-correlation waveform for each receiver pairing.

12. The method of claim 11, wherein one or more line attributes for the one or more hyperbolic lines are varied to display the additional information.

13. The method of claim 2, further comprising:

selecting a location in the image; and

displaying each cross-correlation in a correlation waveform, wherein the cross-correlation data for the location is indicated on each waveform.

14. The method of claim 1, further comprising displaying additional information associated with a signal emitter.

15. The method of claim 14, wherein the additional information associated with the signal emitter comprises a location of the signal emitter.

16. The method of claim 1, further comprising adding a signal to the computed cross-correlation data.

17. A system for displaying location information from cross-correlation data, the system comprising:

a central processing device;

a plurality of receivers connected to the central processing device; and

a display connected to the central processing device and operable to display one or more images of location information, wherein the central processing device is operable to compute a cross-correlation for one or more receiver pairings from the plurality of receivers and process the cross-correlation results to obtain the one or more images of location information.

18. The system of claim 17, wherein the central processing device comprises a computer.

19. The system of claim 17, wherein the central processing device comprises one or more receivers in the plurality of receivers.