Method and system for locating signal jammers

• US 8,446,310 B2
• Filed: 06/12/2009
• Issued: 05/21/2013
• Est. Priority Date: 08/22/2008
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Law, Sarah E., Corwin, Charles A., Fisher, David C.
• Primary Examiner(s): Barker, Matthew M
• Application Number:
  US12/483,729
• Publication Number:
  US 20100045506A1
• Time in Patent Office: 1,439 Days
• Field of Search: 342/16
• US Class Current: 342/16
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: G01S 3/02 using radio waves
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04K 3/22 including jamming detection and monitoring

Abstract

In a method embodiment, a method includes receiving data generated at one or more monitor systems capable of monitoring for electromagnetic signals. The data is related to characteristics of a signal. The characteristics may include at least two of a respective power of the signal, a respective frequency of the signal, a time of arrival of the signal, and an angle of arrival the signal. A computing system automatically selects at least a subset of the received data. The selection is based at least partially on a physical condition at a location proximate to the monitor systems. The computing system calculates a location of a source of the signal at least in part by processing the subset of the received data. The method further includes determining that the first signal is jamming a second signal. The determination is based at least in part on the calculated location.

Claims

1. A method comprising:

receiving signal data generated at one or more monitor systems operable to monitor for electromagnetic signals, the signal data related to a plurality of characteristics of a first signal, the plurality of characteristics of the first signal comprising at least two of;

a respective power of the first signal as measured at each of the one or more monitor systems;

a respective frequency of the first signal as measured at each of the one or more monitor systems;

a time the first signal arrived with respect to each of the one or more monitor systems; and

an angle the first signal arrived with respect to each of the one or more monitor systems;

accessing, by a computing system, situational data, wherein the situational data includes information of a physical condition at a location proximate to the one or more monitor systems, wherein the physical condition at the location proximate to the one or more monitor systems is selected from the group consisting of;

the respective locations of at least two of the one or more monitor systems relative to each other;

a physical terrain topography;

a manmade topography;

a value indicating the population density located within a predetermined range of the one or more monitor systems; and

the weather at the one or more monitor systems;

selectively discarding, automatically by the computing system, received signal data according to a signal characteristic, the discarding based at least partially on the information of the physical condition;

calculating by the computing system a location of a source of the first signal at least in part by processing retained signal data according to a signal characteristic to generate a preliminary location for the signal characteristic and blending preliminary locations generated for the plurality of characteristics of the first signal; and

determining that the first signal is jamming a second signal, the determination based at least in part on the calculated location.

2. The method of claim 1, wherein the received data comprises time-of-arrival data related to the time the signal arrived with respect to at least two of the one or more monitor systems, wherein the time-of-arrival data includes a time stamp of a feature of the first signal associated with an interfering signal, wherein the location of the source of the signal is determined at least in part using a difference between time stamps generated by the at least two monitor systems, and wherein an error between time stamps of the at least two monitoring systems is less than 5 nanoseconds.

3. The method of claim 1, wherein calculating by the computing system the location of the source of the signal comprises calculating a probability that the source is located at a position for each of a first plurality of positions.

4. The method of claim 3, wherein each position of the first plurality of positions corresponds to a respective geospatial area having a first size;

and

further comprising automatically optimizing the calculated location of the source at least in part by calculating a probability that the source is located at a position for each position of a second plurality of positions each corresponding to a respective geospatial area having a second size less than the first size, the respective geospatial areas corresponding to the first plurality of positions collectively comprising the respective geospatial areas corresponding to the second plurality of positions.

5. The method of claim 1, wherein at least one of the one or more monitor systems is capable of navigating toward the source of the signal using at least the calculated location of the source.

6. The method of claim 5, wherein the at least one of the one or more monitor systems is capable of disabling the source of the signal.

7. The method of claim 1, further comprising communicating an output displayable on a display as a digital map comprising a marker indicating the calculated location of the source of the signal.

8. The method of claim 1, wherein blending preliminary locations generated for the plurality of characteristics of the first signal includes weighting a first type of signal characteristic differently from a second type of signal characteristic to calculate the location of the source of the first signal.

9. A jammer locater system comprising:

a reporting system in communication with a network of monitor systems, the reporting system comprising a processor and a receiver, the reporting system configured to;

receive signal data generated by the network of monitor systems, the signal data related to a plurality of characteristics of a signal, the plurality of characteristics of the signal comprising at least two of;

a respective power of the first signal as measured at each of the one or more monitor systems;

a respective frequency of the first signal as measured at each of the one or more monitor systems;

a time the first signal arrived with respect to each of the one or more monitor systems; and

an angle the first signal arrived with respect to each of the one or more monitor systems;

access situational data, wherein the situational data includes information of a physical condition at a location proximate to the one or more monitor systems, wherein the physical condition at the location proximate to the network of monitor systems is selected from the group consisting of;

a geometric distribution of the network of monitor systems;

a physical terrain topography;

a manmade topography;

a value indicating the population density located within a predetermined range of the one or more monitor systems; and

the weather at the one or more monitor systems;

automatically selectively discard received signal data according to a signal characteristic, the discarding based at least partially on the information of the physical condition at a location proximate to the one or more monitor systems;

calculate a location of a source of the signal at least in part by processing retained signal data according to a signal characteristic to generate a preliminary location for the signal characteristic and blending preliminary locations generated for the plurality of characteristics of the signal; and

determine that the first signal is jamming a second signal, the determination based at least in part on the calculated location.

10. The jammer locater system of claim 9, wherein the received data comprises time-of-arrival data related to the time the signal arrived with respect to at least two of the network of monitor systems, wherein the time-of-arrival data includes a time stamp of a feature of the first signal associated with an interfering signal, wherein the location of the source of the signal is determined at least in part using a difference between time stamps generated by the at least two monitor systems, and wherein an error between time stamps generated by the at least two monitoring systems is less than 5 nanoseconds.

11. The jammer locater system of claim 9, wherein the reporting system is configured to calculate a probability that the source is located at a position for each of a first plurality of positions.

12. The jammer locater system of claim 11, wherein:

each position of the first plurality of positions corresponds to a respective geospatial area having a first size; and

the reporting system is configured to automatically optimize the calculated location of the source at least in part by calculating a probability that the source is located at a position for each position of a second plurality of positions each corresponding to a respective geospatial area having a second size less than the first size, the respective geospatial areas corresponding to the first plurality of positions collectively comprising the respective geospatial areas corresponding to the second plurality of positions.

13. The jammer locater system of claim 9, wherein at least one monitor system of the network of monitor systems is configured to navigate toward the source of the signal using at least the geolocation of the source calculated by the reporting system.

14. A non-transitory computer readable medium including instructions that, when performed by one or more processors, cause the one or more processors to:

receive signal data generated at one or more monitor systems operable to monitor for electromagnetic signals, the signal data related to a plurality of characteristics of a first signal, the plurality of characteristics of the first signal comprising at least two of;

a respective power of the first signal as measured at each of the one or more monitor systems;

a respective frequency of the first signal as measured at each of the one or more monitor systems;

a time the first signal arrived with respect to each of the one or more monitor systems; and

an angle the first signal arrived with respect to each of the one or more monitor systems;

access situational data, wherein the situational data includes information of a physical condition at a location proximate to the one or more monitor systems, wherein the physical condition at the location proximate to the one or more monitor systems is selected from the group consisting of;

the respective locations of at least two of the one or more monitor systems relative to each other;

a physical terrain topography;

a manmade topography;

a value indicating the population density located within a predetermined range of the one or more monitor systems; and

the weather at the one or more monitor systems;

automatically selectively discard received signal data according to a signal characteristic, the discarding based at least partially on the information of the physical condition at a location proximate to the one or more monitor systems;

calculate a location of a source of the signal at least in part by processing retained data according to a signal characteristic to generate a preliminary location for the signal characteristic and blending preliminary locations generated for the plurality of characteristics of the first signal; and

determine that the first signal is jamming a second signal, the determination based at least in part on the calculated location.

15. The computer-readable medium of claim 14, wherein the received data comprises time-of-arrival data related to the time the signal arrived with respect to at least two of the one or more monitor systems, wherein the time-of-arrival data includes a time stamp of a feature of the first signal associated with an interfering signal, wherein the location of the source of the signal is determined at least in part using a difference between time stamps generated by the at least two monitor systems, and wherein an error between time stamps generated by the at least two monitoring systems is less than 5 nanoseconds.