Method and system for collecting and surveying radio communications from a specific protected area of operations in or around a compound

• US 7,558,582 B2
• Filed: 12/15/2005
• Issued: 07/07/2009
• Est. Priority Date: 04/21/2004
• Status: Expired due to Fees

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Karlsson, Lars
• Primary Examiner(s): Tran; Pablo N
• Application Number:
  US11/303,601
• Publication Number:
  US 20070173263A1
• Time in Patent Office: 1,300 Days
• Field of Search: 455/456.1, 455/404.2, 4554141-415, 455/423, 4554562-4566, 455/9, 455/67.11, 455/67.16, 370/241, 370/252, 370/465, 370/265, 342/417, 342/449, 342/123, 342/126, 342/139, 342/357, 375130-135, 375/138, 375/139, 375144-146, 375/344, 375/346, 375/350, 375/260, 375/262
• US Class Current: 455/456.1
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A Method and System for Collecting and Surveying Radio Communications From a Specific Protected Area of Operations in or Around a Compound. It is an object of the present invention to provide just such a method to automatically detect communications signals in near real time, from any selectable sub-area of a compound. Such a system would greatly enhance the operational capabilities of the twenty-first century organization by providing a real-time capability to secure radio communications in and around a compound. The system has all the abilities of the system described in the '"'"'976 application, but is further able to automatically detect the direction of the incoming signals (relative to two or more collector subsystems in communication with each other), and thereafter to add that information to the surveillance decision logic such that the actual geographical location, as adjusted by the calibration information for the particular compound surveillance decision logic. Secondly, the system has the capability of being calibrated such that the particular RF environment of the compound in question is uniquely mapped. The calibration tables maintained by each network-attached directional collection node of the system invention in order to provide a more robust and accurate signal geo-location system. Thirdly, the system is able to automatically pinpoint the geographic area of the source of the incoming signals and add that information to the monitoring decision logic. Finally, the system provides a user interface to operators so they can easily select areas to monitor, and easily calibrate the system for maximum precision.

Claims

1. A directional electronic signal geolocation and identification system, comprising:

a wideband signal collection front end subsystem, comprising;

a wideband receiver for receiving RF signals transmitted by an RF signal transmitter across a broad spectrum said receiver comprising first, second and third antennae means for receiving RF signals simultaneously, said antennae means in geographically spaced relation;

a digitizer for creating an individual continuous stream of digitized data representing each said antennae means'"'"'received RF signals;

a digital data conversion means for converting said individual digitized data stream into FFT frequency bins by individual stream;

direction determination means for determining a direction from each said antennae means to said RF transmitter; and

apparent location determination means for determining an apparent location of said RF signal transmitter from said determined directions;

a signal evaluation logic module, comprising;

a comparing means for comparing each said frequency bin to configurable preset lockout frequency bins;

a peak detection means for evaluating and calculating the amplitude value for each bin by using a configurable number of data point samples for each of those bins;

a windowing means for evaluating and calculating the amplitude value for each bin by using a configurable number of data point samples for each of those bins; and

geographical location correction means for determining a corrected geolocation of said RF transmitter, said geographical location correction means comprising correction means for comparing said apparent location to a calibrated apparent location to determine a corrected geolocation of said RF transmitter.

2. The system of claim 1, further comprising policy enaction means for enacting response policy responsive to said corrected geolocation and said converted digitized data streams.

3. The system of claim 2, wherein said policy enaction means is further responsive to user-defined areas of interest.

4. The system of claim 3, wherein said system further consolidates said individual frequency bins from said wideband signal collection front end subsystems representing said individual digitized data streams into a single frequency bin.

5. The system of claim 4, wherein said digital data conversion means comprises means for converting said digitized data from a time domain to a frequency domain.

6. The system of claim 5, wherein said digital data conversion means comprises means for converting said frequency domain converted data from separate real and imaginary components to normalized amplitude data.

7. The system of claim 6, wherein said normalized amplitude data is categorized by frequency bins.

8. The system of claim 7, wherein said comparing means comprises comparing data in said frequency bins to frequency lockouts.

9. The system of claim 8, further comprising peak detection means for evaluating the amplitude of said frequency bins.

10. The system of claim 9, wherein said windowing means for evaluating each bin to be within configurable amplitude bound limits.

11. The system of claim 10, further comprising means for comparing said amplitude-evaluated signal to a pre-established signal priority list.

12. The system of claim 11, wherein said signal priority logic means further compares said amplitude-evaluated signal to a real-time priority request.

13. The system of claim 12, wherein said first, second and third antennae means are in geographically fixed locations less than or equal to one mile from one another.

14. A method for geolocating RF signal transmissions, comprising the steps of:

creating a calibration table, said calibration table including apparent transmitter location, actual transmitter location and transmitter frequency;

detecting an analog RF signal transmission emanating from a signal transmitter at a wideband signal collection front end system, each said detected RF signal transmission first having been received by first, second and third antennae means associated with said said wideband signal collection front end system, said antennae means located in geographically spaced relation to the other antennae means associated with that said system;

digitizing each said detected RF signal transmission into first, second and third digitized signals;

converting said each digitized signals into first, second and third frequency bins;

analyzing phase characteristics of each said digitized signal;

determining a detected apparent geographical location of said signal transmitter responsive to said analyzing; and

comparing said detected apparent geographical location to said apparent transmitter location data of said calibration table to arrive at a corrected location responsive to said comparing and said calibration table actual transmitter location data.

15. The method of claim 14, wherein said calibration table creating step comprises:

activating said wideband front end signal collection systems;

positioning an RF transmitter at a known geolocation within a compound;

transmitting a desired frequency from said RF transmitter;

detecting said transmitted signal;

determining an apparent transmitter location by triangulating said detected signal by said antennae means;

determining an actual transmitter location; and

recording said apparent transmitter location, said actual transmitter location and said transmitted signal frequency in said calibration table.

16. The method of claim 15, wherein said calibration table creating step comprises repeating said transmitting, detecting, apparent transmitter location determining, actual transmitter location determining and said recording steps for a group of frequencies of interest.

17. The method of claim 16, wherein said calibration table creating step comprises repositioning said RF transmitter to a plurality of known locations within said compound and repeating said transmitting, detecting, apparent transmitter location determining, actual transmitter location determining and said recording steps for said group of frequencies of interest at each said known location within said compound.