Finding cell phones in rubble and related situations

• US 20040198381A1
• Filed: 10/08/2002
• Published: 10/07/2004
• Est. Priority Date: 10/08/2002
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Stearns, Stephen D., Siegel, Neil G., Jennetti, Anthony G.
• Granted Patent: US 7,046,987 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

Systems and methods are provided for locating a transmission signal from a radio transmission emitter device, such as a cell phone, in a rescue area. A pilot signal is employed to lock onto a transmission signal of one or more radio transmission devices located in a rescue area. A signal separation routine extracts desired transmission signals from emitter devices located in the rescue area from other signals coexisting on similar frequency bands and interfering with the desired transmission signals. An estimated location of transmission signals from emitter devices located in the rescue area is determined based on one or more transmission signal location techniques. The area is searched based on the estimated location of the transmission signal. If the emitter transmitting the transmission signal is not found, devices in the system are moved and the location estimation is repeated.

Claims

1. A transmission signal location system for locating at least one emitter device in a rescue area, the system comprising:

a base station that transmits a plurality of pilot signals to lock onto an emitter within a rescue area;

a plurality of receivers operative to receive transmission signals from at least one emitter device within the rescue area, the emitter device signals being separated from other interfering signals within the same frequency band; and

a master device that determines an estimated location of the at least one emitter device within the rescue area.

2. The system of claim 1, the plurality of receivers employ a cochannel signal processing routine that separates emitter device signals from other interfering signals within the same frequency band.

3. The system of claim 1, the plurality of pilot signals comprising pilot signals in a plurality of frequency bands in a plurality of common wireless standards.

4. The system of claim 3, the plurality of common wireless standards comprising at least two of AMPS, NAMPS, NMT 900, TACS, ETACS, NMT 450, C-450, RTMS, JTACS, NTACS, DAMPS (TDMA, IS-54, IS-136), GSM, DCS 1800, PCS (PCS 1800 and PCS 1900), PHS, CDMA (narrowbands, widebands, 800 MHz, 1.8 GHz or 1.9 GHz), iDEN, EDACS, FHMA, JDC, TETRA, APCO-25, and MPT-1327:

5. The system of claim 3, the base station transmitting pilot signals in sets of frequencies, so as to transmit all frequencies of all desired common wireless standards within a desirable time limit.

6. The system of claim 1, at least one of the plurality of receivers having an antenna array that cooperates with a direction finding routine to determine a direction of an emitter transmission signal within the rescue area.

7. The system of claim 6, the master device comprising a master control unit that receives the separated emitter device signals and direction-of-arrival (DOA) information from the plurality of receivers and determines an estimated location of the at least one emitter device within the rescue area based on a time-difference-of-arrival (TDOA) technique.

8. The system of claim 1, the master device comprising a master control unit that receives the separated emitter device signals from the plurality of receivers and determines an estimated location of the at least one emitter device within the rescue area based on a time-difference-of-arrival (TDOA) technique.

9. The system of claim 1, the master device invokes a calibration routine that initiates a geographical position routine that determines geographical position information associated with the plurality of receivers.

10. The system of claim 9, the geographical position information being utilized in conjunction with the separated emitter device signals from the plurality of receivers to determine an estimated location of the at least one emitter device within the rescue area.

11. The system of claim 9, the geographical position information being determined employing one of a Global Positioning System (GPS) technique, a laser range finder technique and a manual entry technique.

12. The system of claim 1, the master device being a master receiver device.

13. The system of claim 1, the base station and master device being integrated into a single integrated unit.

14. The system of claim 1, master device executing one of a triangulation and trilateration technique to determine an estimated location of the at least one emitter device, as a minimum, or higher order location determining techniques.

15. A method for locating a transmission signal in a rescue area, the method comprising:

locating a plurality of receivers around a rescue area;

determining geographical position information associated with the plurality of receivers;

transmitting a plurality of pilot signals toward the rescue area;

monitoring for transmission signals from at least one emitter device within the rescue area;

separating emitter device signals within the rescue area from other interfering signals within the same frequency band; and

determining an estimated location of the at least one emitter device within the rescue area.

16. The method of claim 15, further comprising conducting a search for the at least one emitter device in the rescue area based on the estimated location.

17. The method of claim 16, further comprising relocating the plurality of receivers around the rescue area if the at least one emitter device is not located and repeating the determining an estimated location of the at least one emitter device.

18. The method of claim 15, the determining geographical position information associated with the plurality of receivers comprising performing one of a GPS location technique, a laser range finding technique and a manual entry technique to determine the geographical position of the plurality of receivers.

19. The method of claim 15, the transmitting a plurality of pilot signals toward the rescue area comprising transmitting pilot signals in a plurality of frequency bands in a plurality of common wireless standards.

20. The method of claim 19, the transmitting a plurality of pilot signals comprising transmitting pilot signals in sets of frequencies, so as to transmit all frequencies of the plurality of common wireless standards within a desirable time limit.

21. The method of claim 15, the separating emitter device signals within the rescue area from other interfering signals within the same frequency band comprising performing a cochannel processing algorithm on the received signals.

22. The method of claim 15, the determining an estimated location of the at least one emitter device within the rescue area comprising executing a direction-of-arrival-technique (DOA) at the plurality of receivers and employing direction finding data and raw signal data in performing a time-difference-of-arrival (TDOA) technique to estimate the location of the at least one emitter device.

23. A system for locating a transmission signal in a rescue area, the system comprising:

means for determining geographical positions of a plurality of receivers placed in a rescue area;

means for transmitting a plurality of pilot signals in the rescue area to connect to at least one emitter device;

means for separating emitter device signals within the rescue area from other interfering signals within the same frequency band;

means for determining a direction of emitter device signals at each of the plurality of receivers; and

means for estimating a location of the at least one emitter device within the rescue area employing direction data, raw signal data of emitter device transmission signals and geographical position data of the plurality of receivers.

24. The system of claim 23, the means for transmitting a plurality of pilot signals transmitting a plurality of pilot signals in sets of frequencies of a plurality of frequency bands in a plurality of common wireless standards.

25. The system of claim 23, the means for separating emitter device signals comprising a cochannel processing algorithm.