EP-4736351-A1 - DIFFERENCE-BASED JAMMER DETECTION SYSTEM

Abstract

Techniques are provided for jammer detection. A methodology implementing the techniques according to an embodiment includes steering a beam in a specified direction to generate a power measurement, the specified direction selected from a plurality of directions, such that the method comprises scanning through the plurality of directions. The method also includes adaptively steering a null in the specified direction and measuring a gain of the received signal in the null direction. The method further includes calculating a difference between the power measurement and the measured gain and generating a difference-based detection that the received signal is associated with a jammer at the specified direction. The difference-based detection is based on a comparison of the power difference to a power difference threshold value. The power difference threshold value is based on a desired probability of false alarm and probability of detection, and/or desired angular resolution.

Inventors

• STOCKMASTER, MICHAEL H.
• LAI, YING CHO J.

Assignees

• BAE SYSTEMS Information and Electronic Systems Integration Inc.

Dates

Publication Date

20260506

Application Date

20240530

Claims (20)

1. 1. A system for detection of signal jammers, the system comprising: a beamforming circuit configured to steer a beam in a specified direction and measure a power of a received signal in the specified direction; an adaptive nulling circuit configured to steer a null in the specified direction and measure a gain of the received signal in the steered null direction; a differencing circuit configured to calculate a difference between the power and the gain; and a jammer assessment circuit configured to detect that the received signal is associated with a jammer, the detection based on a comparison of the difference to a threshold value.
2. 2. The system of claim 1 , wherein the specified direction comprises an azimuth angle and an elevation angle, the specified direction is selected from a plurality of directions, and the system is configured to scan through the plurality of directions.
3. 3. The system of claim 1 , wherein the threshold value is selected based on a desired probability of false alarm (Pfa), a desired probability of detection (Pd), and/or a desired angular resolution.
4. 4. The system of claim 1, further comprising a jammer direction finding (DF) circuit configured to generate a DF pattern for identification of locations of potential signal jammers based on jamming signals included in the received signal.
5. 5. The system of claim 4, wherein the jammer DF circuit is configured to generate the DF pattern based on execution of a minimum variance distortionless response (MVDR) process or a multiple signal classification (MUSIC) process.
6. 6. The system of claim 4, wherein the threshold value is a first threshold value, and the system further comprises an angle of arrival (AO A) generation circuit configured to estimate AO As of the jamming signals associated with the potential signal jammers based on a comparison of gain values of the DF pattern to a second threshold value, the second threshold value selected based on a desired Pfa, a desired Pd, and/or a desired angular resolution.
7. 7. The system of claim 6, wherein the estimated AOA is employed as the specified direction.
8. 8. A computer program product including one or more non- transitory machine- readable mediums encoded with instructions that when executed by one or more processors cause a process to be carried out for detection of signal jammers, the process comprising: steering a beam in a specified direction and measuring a power of a received signal in the specified direction; adaptively steering a null in the specified direction and measuring a gain of the received signal in the steered null direction; calculating a difference between the power and the measured gain; and detecting that the received signal is associated with a jammer, the detection based on a comparison of the difference to a threshold value.
9. 9. The computer program product of claim 8, wherein the specified direction comprises an azimuth angle and an elevation angle, and the process further comprises selecting the specified direction from a plurality of directions and scanning through the plurality of directions.
10. 10. The computer program product of claim 8, wherein the threshold value is selected based on a desired probability of false alarm (Pfa), a desired probability of detection (Pd), and/or a desired angular resolution.
11. 11. The computer program product of claim 8, wherein the process further comprises generating a DF pattern for identification of locations of potential signal jammers based on jamming signals included in the received signal.
12. 12. The computer program product of claim 11, wherein the process further comprises generating the DF pattern based on execution of a minimum variance distortionless response (MVDR) process or a multiple signal classification (MUSIC) process.
13. 13. The computer program product of claim 11, wherein the threshold value is a first threshold value, and the process further comprises estimating angles of arrival (AO As) of the jamming signals associated with the potential signal jammers based on a comparison of gain values of the DF pattern to a second threshold value, the second threshold value selected based on a desired Pfa, a desired Pd, and/or a desired angular resolution.
14. 14. The computer program product of claim 13, wherein the process further comprises employing the estimated AOA as the specified direction.
15. 15. A method for detection of signal jammers, the method comprising: steering, by a processor based system, a beam in a specified direction and measuring a power of a received signal in the specified direction; adaptively steering, by the processor based system, a null in the specified direction and measuring a gain of the received signal in the steered null direction; calculating, by the processor based system, a difference between the power and the measured gain; and detecting, by the processor based system, that the received signal is associated with a jammer, the detection based on a comparison of the difference to a threshold value.
16. 16. The method of claim 15, wherein the specified direction comprises an azimuth angle and an elevation angle, and the method further comprises selecting the specified direction from a plurality of directions and scanning through the plurality of directions.
17. 17. The method of claim 15, wherein the threshold value is selected based on a desired probability of false alarm (Pfa), a desired probability of detection (Pd), and/or a desired angular resolution.
18. 18. The method of claim 15, wherein the method further comprises generating a DF pattern for identification of locations of potential signal jammers based on jamming signals included in the received signal.
19. 19. The method of claim 18, wherein the method further comprises generating the DF pattern based on execution of a minimum variance distortionless response (MVDR) process or a multiple signal classification (MUSIC) process.
20. 20. The method of claim 18, wherein the threshold value is a first threshold value, and the method further comprises estimating angles of arrival (AO As) of the jamming signals associated with the potential signal jammers based on a comparison of gain values of the DF pattern to a second threshold value, the second threshold value selected based on a desired Pfa, a desired Pd, and/or a desired angular resolution, and employing the estimated AOA as the specified direction.

Description

DIFFERENCE-BASED JAMMER DETECTION SYSTEM HELD OF DISCLOSURE [0001] The present disclosure relates to electronic counter-measures, and more particularly, to a jammer detection system. BACKGROUND [0002] Situational awareness is an important aspect of military operations, and operations in other conflict scenarios, and often includes direction finding (DF) for sources of signal jammers. DF techniques, however, may produce false alarms (e.g., an indication of jamming signal sources that are not real). These false alarms can distract from real threats, burden processing systems and operators of those systems, and potentially result in unintended actions with undesired consequences. BRIEF DESCRIPTION OF THE DRAWINGS [0003] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. [0004] Figure 1 illustrates an implementation including multiple jammer detection systems, in accordance with certain embodiments of the present disclosure. [0005] Figure 2 is a block diagram of one of the jammer detection systems of Figure 1, configured in accordance with certain embodiments of the present disclosure. [0006] Figure 3 illustrates a beamformer output plot and an adaptive nulling gain plot, in accordance with certain embodiments of the present disclosure. [0007] Figure 4 illustrates a difference plot, in accordance with certain embodiments of the present disclosure. [0008] Figure 5 is a block diagram of another of the jammer detection systems of Figure I, configured in accordance with certain embodiments of the present disclosure. [0009] Figure 6 illustrates a DF pattern plot, in accordance with certain embodiments of the present disclosure. [0010] Figure 7 is a flowchart illustrating a methodology for jammer detection, in accordance with an embodiment of the present disclosure. [0011] Figure 8 is a block diagram of a platform for the jammer detection system of Figure 1 , in accordance with certain embodiments of the present disclosure. [0012] Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent in light of this disclosure. DETAILED DESCRIPTION [0013] Techniques are provided herein for detection of jammer signals. The techniques may be used to, for example, reduce probability of false alarm (Pfa) and/or improve probability of detection (Pd). As described above, accurate and reliable direction finding of jammer signals can improve situational awareness, but false alarms can distract from real threats and can negatively impact operations. While detection improvements can be achieved through the deployment of multiple cooperating DF platforms (e.g., in a multi-ship, multi-platform scenario), this approach adds significant cost and complexity and relies on the ability to coordinate and communicate between platforms, which may be difficult or impossible in some hostile environments. [0014] To this end, techniques are provided to improve reliability of jammer signal detection. In an example, the improvement manifests with respect to a reduction in false alarms and can be accomplished using data provided from a single sensor (e.g., an antenna array or beamforming array), without requiring information or assistance from other platforms or outside sources. In some embodiments, the disclosed jammer signal detection techniques include difference-based jammer detection. Difference-based jammer detection exploits the fact that an actual jamming signal will generally be associated with a relatively higher measured signal power when a beam is steered in the direction of the jammer compared to when a null is steered in the direction of the jammer. The difference between the measured power of the steered beam and the gain (or attenuation) of the adaptively-steered null can be used, as at least one factor, to detect jammers and distinguish between actual jammers and false alarms, as will be described in greater detail below. Additionally, a number of thresholding parameters can be set to balance or otherwise adjust or tune the Pfa and Pd of the system, depending on given mission requirements or needs of the system operators. [0015] A system to implement the disclosed techniques can be hosted on, or otherwise be incorporated into the electronic systems of an aircraft or other vehicle, a navigation system, an anti-jamming system, a tracking ground station, a personal computer, workstation, laptop computer, tablet, touchpad, portable computer, handheld computer, cellular telephone, smartphone, embedded system, or any other platform where jamming detection is needed. [0016] In accordance with an embodiment, an example methodology to implement these techniques includes steering a beam in a specified direction to generate a power measure