KR20230145033A - Ceiling reactive jammer - Google Patents

Abstract

The present invention relates to a jamming device (1) for the protection of targets on the Earth's surface from radiofrequency (RF) threats of space, satellite or air type, the jamming device (1) comprising: It includes RF threat detection means (11), RF jamming means (12) and control system (13). The RF threat detection means 11 includes a plurality of receiving antennas 111, an RF threat detection unit 112, and one or more predefined RF threat-related libraries 113. The receiving antennas 111 are configured to receive RF signals with elevation angles of arrival that are greater than or equal to a given minimum elevation angle to provide elevation angle coverage of interest. The RF threat detection unit 112 detects the presence of an RF threat based on RF signals received by the receiving antennas 111 and a predefined RF threat library(s) 113 and detects the RF threat. In one case, determining the respective type of detected RF threat based on RF signals received by receiving antennas 111 and predefined RF threat-related library(s) 113; estimating the respective direction of arrival of the detected RF threat based on the RF signals received by the receiving antennas 111; It is configured to alert the control system 13 about the detected RF threats and provide the control system 13 with each type of arrival and each direction of arrival of the detected RF threats. The predefined RF threat-related library(s) 113 allows the RF threat detection unit 112 to detect the presence of the RF threat(s) of interest and based on the RF signals received by the receiving antennas 111. and includes information related to one or more RF threats of interest so as to be able to determine the respective type of the RF threat(s) of interest. The control system 13 includes a control unit 131 and one or more predefined RF-jamming-actions-related libraries 132. When an RF threat is detected by the RF threat detection unit 112, the control unit 131 stores the respective type and predefined RF jamming action-related library(s) 132 determined by the RF threat detection unit 112. Based on this, determine an RF jamming action to be performed for the detected RF threat; The RF jamming means 12 is configured to operate the RF jamming means 12 to perform a determined RF jamming action against a detected RF threat. The predefined RF jamming action related library(s) 132, for each RF threat of interest inserted into the predefined RF threat library(s) 113, includes one or more RF jamming actions to be performed on the RF threat of interest. Contains respective information related to their respective RF jamming actions. The RF jamming means 12 is operable by the control unit 131 when an RF threat is detected by the RF threat detection unit 112, and a plurality of transceiver antennas 121 - the plurality of transceiver antennas also configured to transmit RF jamming signals for a detected RF threat to provide elevation angle coverage of interest, track the detected RF threat, and perform an RF jamming action determined by the control unit 131; and an RF jamming signal generating unit 122 configured to generate RF jamming signals to be transmitted by transceiver antennas 121 in response to detected RF threats to perform the RF jamming operation.

Description

Ceiling reactive jammer

Cross-reference to related applications

This patent application claims priority from European Patent Application No. 20425047.6, filed on November 5, 2020, the entire disclosure of which is incorporated herein by reference.

Technical field of invention

The present invention relates generally to the field of Electronic Countermeasures (ECM).

More specifically, the present invention relates to zenithal reactive jammers, i.e. radiofrequency (RF) remote sensing sensors or systems (e.g., radar type sensors/systems) that operate at high elevation angles. Responsive jamming (e.g. imaging radars), synthetic aperture radar (SAR) installed on space or airborne platforms - e.g. satellites, aircraft, drones, etc. jamming) device.

As is known, the purpose of a jamming system for protection against radar or SAR sensors/systems is to suppress the ability of enemy sensors to recognize and/or extract relevant information, thereby suppressing the area of interest, site, e.g. It is to protect one) or a series of assets.

In the specific case of SAR sensors, the goal is to degrade the quality of the image as much as possible to defocus or otherwise obscure the area of interest and thus provide adequate protection in maritime or terrestrial contexts.

For example, US Patent No. 10,852,391 B2 relates to a method and related device for jamming synthetic aperture radars. Specifically, U.S. Patent No. 10,852,391 B2 describes a method for jamming airborne SAR-type radars implemented by a radar jamming device comprising a group of at least two cooperative units surrounding a ground area to be protected, comprising:

• At least two units of the group provide radar detection capabilities;

• At least one unit of this group provides radar jamming capabilities;

ㆍEach unit providing radar detection functionality includes a reception and processing module configured to analyze received signals;

ㆍEach unit providing radar jamming function is configured to generate and transmit jamming signals;

ㆍEach unit is interconnected by at least one bidirectional data link and is synchronized by a common clock.

More specifically, the method according to US Patent No. 10,852,391 B2,

• Identifying whether received signals correspond to SAR signals;

· Characterizing the received SAR signal for a predefined period of time that is shorter than the duration of the SAR signal;

ㆍCalculating a filter adapted to the pulse of the received SAR signal;

ㆍPerforming pulse compression of the SAR signal received at each repetition using the adapted filter to obtain a Doppler history linked to the movement of the platform equipped with the radar;

ㆍPeriodically and repeatedly characterize the received signal over a predefined period longer than the regression of the SAR signal, from one regression to the next, establishing the rate of displacement of the radar and the distance between the radar and the area to be protected steps;

ㆍCalculating jamming signals to be transmitted for each point of the protected area to consistently jam the SAR type radar in the range and Doppler axes; and

ㆍIncludes transmitting the calculated jamming signals.

In this context, the characteristics of SAR technology (in terms of the physical properties of SAR sensors and SAR processing and imaging processes) and the airborne or space/satellite platforms typically used for installation and transportation of these sensors (in terms of kinematic properties) are Considering the characteristics, it should be noted that, unfortunately, effective success of the jamming operation is not guaranteed.

Moreover, similar limitations inherent in the effects of processing on jamming effectiveness can also be found in the case of high-resolution imaging radar sensors, whose use has increased in recent years.

In addition, the kinematic profile of the aforementioned platforms, which is particularly challenging for traditional electronic defense systems, is an additional limiting factor.

Fundamentally, known types of jamming systems do not have the architectural flexibility and responsiveness necessary to ensure simultaneous coverage of all the multiple aspects that need to be considered when countering the aforementioned types of threats.

In practice, several factors must be addressed to ensure the effectiveness of electronic defense in these contexts.

In particular, technical difficulties relate to several aspects:

ㆍLong range (especially for contrast with satellite sensors);

• Elevation angles of interest for such threats (satellite or aerial); and

ㆍProcessing of receivers.

Regarding the first aspect, in terms of threat detection capability, this requires high sensitivity of the receiver used.

Subsequently, the need to provide disruption with timing that is compatible with the evolution of the ongoing threat should be considered. This is, in principle, true for a whole range of platforms with rapidly evolving kinematic profiles, for which the alert and connection times are very short.

Additionally, in naval/maritime or land contexts, whether it is a matter of point defense (e.g. protection of a single naval platform, coverage of a single base, site and/or land convoy, etc.) or defense of a wider area (e.g. protection of a fleet of ships) , coverage of a series of bases, sites and/or land transports, etc.), the elevation angles involved are not typical of commonly used electronic defense systems and even provide effective protection against these threats. There is no flexibility to do so.

Another very difficult aspect is the high power required for the jamming system to make it effective. In fact, the latest generation of high-resolution imaging radars have a high process gain in the coherent integration of signals reflected from the soil/target during the illumination time of the observation area. Therefore, for a jamming system to be effective, it must be able to compensate for this gain.

In view of the foregoing, the object of the present invention is to develop systems operating at radio frequencies (RF) and high altitude angles (e.g. satellite/ It provides an innovative jamming device for protection against airborne radar (SAR) or remote sensing sensors.

These and other objects are achieved by the invention relating to a jamming device as defined in the appended claims.

In particular, the invention relates to a jamming device for the protection of targets on the Earth's surface from radio frequency (RF) threats of space, satellite or air type,

The jamming device is,

ㆍRF threat detection means;

ㆍRF jamming means; and

ㆍIncludes control system,

RF threat detection means,

ㆍMultiple receiving antennas;

ㆍRF threat detection unit; and

ㆍContains one or more predefined RF threat-related libraries,

The receiving antennas are configured to receive RF signals having elevation angles of arrival that are greater than or equal to the minimum elevation angle to provide elevation angle coverage of interest;

The RF threat detection unit,

ㆍDetect the presence of an RF threat based on RF signals received by the receiving antennas and a predefined RF threat-related library(s);

ㆍIf an RF threat is detected,

- determine the respective type of detected RF threat based on RF signals received by the receiving antennas and predefined RF threat-related library(s),

- Estimate the direction of arrival of each detected RF threat based on the RF signals received by the receiving antennas,

- configured to alert the control system about the detected RF threat, providing the control system with the respective arrival type and respective arrival direction of the detected RF threat;

The predefined RF threat-related library(s) allows the RF threat detection unit to detect the presence of the RF threat(s) of interest and detect the RF threat(s) of interest based on RF signals received by receiving antennas. Contains information related to one or more RF threats of interest to enable determining their respective types;

The control system is,

ㆍControl unit; and

ㆍOne or more predefined RF jamming action libraries;

When an RF threat is detected by the RF threat detection unit, the control unit

ㆍDetermine the RF jamming action to be performed on the detected RF threat based on the respective type determined by the RF threat detection unit and the predefined RF jamming action related library(s);

ㆍConfigured to operate the RF jamming means so that the RF jamming means performs a determined RF jamming action for a detected RF threat,

The predefined RF jamming action related library(s) is, for each RF threat of interest inserted into the predefined RF threat related library, associated with one or more respective RF jamming actions to be performed for the RF threat of interest. Contains your information,

The RF jamming means is operable by the control unit when an RF threat is detected by the RF threat detection unit,

ㆍMultiple transceiver antennas - The plurality of transceiver antennas are,

- also provides elevation angle coverage of said interest,

- Track detected RF threats,

- configured to transmit RF jamming signals in response to the detected RF threat to perform an RF jamming action determined by a control unit; and

ㆍIt includes an RF jamming signal generating unit configured to generate RF jamming signals to be transmitted by transceiver antennas in response to a detected RF threat to perform the RF jamming operation.

For a better understanding of the invention, some preferred embodiments (which are provided for illustrative purposes only and are absolutely not limiting or binding examples) are now described with reference to the accompanying drawings (not to scale). will be:
ㆍFigure 1 schematically shows a jamming device according to a preferred embodiment of the present invention.
ㆍFigure 2 schematically shows the RF threat detection means of the jamming device of Figure 1.
• Figure 3 schematically shows an example of pointing the receiving antennas of the RF threat detection means of Figure 2 for detecting satellite SAR signals.
• Figure 4 schematically shows an example of an embodiment of the receiving antennas for detecting satellite SAR signals.
ㆍFigure 5 schematically shows the control system of the jamming device of Figure 1.
• FIG. 6 schematically shows the RF jamming means of the jamming device of FIG. 1.
• FIG. 7 shows an example of an embodiment of the jamming device of FIG. 1 for use on naval platforms to detect and jam satellite SAR signals.
• Figures 8 and 9 show examples of satellite SAR images and corresponding SAR images acquired in the presence of jamming provided by the jamming device according to the invention in a satellite anti-SAR configuration, respectively.

The following description is provided to enable any person skilled in the art to understand, make, and use the present invention. Various modifications to the described embodiment will be readily apparent to those skilled in the art, and the general principles disclosed herein may be applied to other embodiments and applications without departing from the scope of protection of the invention as defined in the appended claims. .

Accordingly, the invention should not be construed as limited to the single embodiments described and shown, but should be accorded the widest protection in accordance with the features defined in the appended claims.

The present invention is directed to land or naval platforms (e.g., land vehicles, It relates to a jamming device for the protection of targets on the ground, mobile or stationary, such as naval units, areas of interest or sites, etc.

For a better understanding of the present invention, Figure 1 shows a block diagram schematically illustrating the high-level functional architecture of a jamming device (indicated throughout as 1) according to a preferred embodiment of the present invention.

In particular, the jamming device 1 (for simplicity will hereinafter simply be referred to as a jammer),

ㆍRF threat detection means (11);

ㆍRF jamming means (12); and

ㆍIncludes control system (13).

In this regard, it is noted that the jammer (1) is preferably constituted by a single device/device in which the RF threat detection means (11), the RF jamming means (12) and the control system (13) are integrated. It is important.

Furthermore, as shown in FIG. 1 , the jammer 1 is preferably operated in a wired or wireless mode by a user interface means 2 external to the jammer 1 (e.g. by a user, i.e. an operator, etc.). connected to a computer, laptop, station, etc.) specifically dedicated to the control of

The RF threat detection means 11 detects RF threats transmitting microwave signals or, more generally, RF signals illuminating the protected object on which the jammer 1 is installed (e.g. an area or site of interest, a land or naval platform, etc.) (e.g. , satellite/airborne SAR sensors/systems, satellite/airborne radar sensors/systems, satellite/airborne RF remote sensing sensors/systems, etc.) at predefined angles (in azimuth and elevation). It represents the passive part of the jammer 1 dedicated to monitoring the sector (angular sector).

Instead, the RF jamming means 12 is an active part of the jammer 1 dedicated to the delivery of RF interference, such as to damage/impede the extraction of relevant information (e.g. location, distance, shape, etc.) related to the object to be protected. represents.

Finally, the control system 13 is:

ㆍManagement of RF threat detection means (11) in relation to surveillance of areas of interest; and

ㆍProvides activation and appropriate operation of the RF jamming means (12) as soon as an alert is received from the RF threat detection means (11).

In this regard, integrating the RF threat detection means 11, the RF jamming means 12 and the control system 13 into a single device/device (i.e. jammer 1) reduces the latency in the transmission of the jammer. It is worth noting that it contributes to reducing latencies.

Figure 2 shows a block diagram schematically illustrating the high-level functional architecture of the RF threat detection means 11, which includes:

ㆍA plurality of receiving antennas 111;

ㆍRF threat detection unit (112); and

ㆍContains one or more predefined RF threat-related libraries 113, and the predefined RF threat-related library(s) 113 are conveniently stored in the internal memory or external memory of the RF threat detection unit 112. It can be.

More specifically, the receiving antennas 111 are configured to receive RF signals having altitude angles of arrival, where the altitude angles of arrival are:

>a given minimum elevation angle (conveniently greater than 20° - preferably comprised between 20° and 65°);

Or, preferably, within a given angular range of altitude defined by a given minimum elevation angle and a given maximum elevation angle that is greater than the given minimum elevation angle (e.g., 20° to 40° or 20° to 20° in the context of an airborne RF threat). Within 45°, or between 30° and 60° or between 30° and 65° or between 30° and 70° in relation to satellite RF threats, or within 60° in relation to zenithal or quasi-zenithal RF threats. altitude angles of arrival within the range of ° to 90° or 65° to 90°).

Accordingly, the receiving antennas 111 (and thus the RF threat detection means 11 ) transmit RF signals with high arrival elevation angles with respect to the jammer 1 (more precisely, with respect to a given horizontal reference plane of the jammer 1 ). It provides elevation angle coverage of the signals, which elevation coverage may also conveniently be zenith or quasi-zenith.

Preferably, the receiving antennas 111 are configured to receive RF signals having the elevation angles of arrival and the azimuth of arrival ranging from 0° to 180° or 0° to 360°, thereby providing the elevation angle coverage In addition, it also provides azimuthal coverage of 180° or 360° around the zenith direction of the jammer 1 (where the zenith direction is perpendicular to the horizontal reference plane).

The receiving antennas 111 can be conveniently realized by a predefined number of antennas, which include:

ㆍHas predefined operating characteristics (directivity, gain, antenna or radiation/power pattern, etc.);

ㆍInstalled/mounted at predefined locations on the jammer (1);

ㆍPoints according to predefined pointing directions,

The predefined number, the predefined operating characteristics, the predefined positions and the predefined pointing directions are set to ensure the aforementioned altitude and azimuth coverage (or more generally, the altitude and azimuth coverage of interest). do.

Conveniently, the receiving antennas 111 are preferably directional antennas with high gain.

Additionally, the receiving antennas 111 preferably have appropriate characteristics in terms of weight and volume to allow or in any case facilitate the integration/installation of the receiving antennas 111 in/on the jammer 1. do.

Figure 3 schematically shows an example of pointing the receiving antennas 111 for detecting satellite SAR signals.

In particular, Figure 3 shows a three-dimensional (3D) Cartesian reference system, where the Cartesian reference system is:

ㆍVertical axis (z) corresponding to the ceiling direction of the jammer (1); and

Defined by two horizontal axes (x and y), orthogonal to each other and perpendicular to the axis (z), defining a given horizontal reference plane of the jammer (1), the latter being the axis (x, y, z) is located at the intersection O (the so-called origin of the 3D Cartesian reference system).

3 also schematically shows the respective pointing directions of the four groups of receiving antennas 111 along with their respective radiation patterns.

In particular, Figure 3 shows the 4 receiving antennas 111 in four quadrants in azimuth (to ensure azimuthal coverage of 360° around the zenith direction) and in altitude to cover the typical illumination directions of SAR satellites. The orientation of the groups is shown.

In this regard, depending on the type of threat of interest, the pointing of the receiving antennas 111 may be appropriate to focus on specific sectors (and, therefore, threats) or to cover sectors that are common to several types of threats. It is important to note that methods can be conveniently redefined. Additionally, the pointing can conveniently be further squint to provide coverage even for kinematics that are quasi-orthogonal to diving air threats and/or jammers (1).

Referring back to the example shown in Figure 3, Figure 4 also schematically shows an example of an embodiment of each individual group of receiving antennas 111, each group of receiving antennas 111 comprising a satellite SAR sensor. This is conveniently realized by three horn antennas (designated 111A, 111B and 111C respectively) which ensure full band coverage for the common frequencies of the fields/systems.

Finally, with regard to the receiving antennas 111 , the use of four groups of receiving antennas 111 also allows, in addition to ensuring the elevation and azimuth coverages of interest, as in the case of the example just described, the In the absence of intelligence data about the trajectory or trajectory of an aircraft (e.g. drone, plane, etc.), it is possible to obtain a rough estimate of the direction of arrival of the RF signal and to direct the RF jamming means 12 appropriately towards the detected threat. It should be noted that pointing is possible.

Meanwhile, with regard to the RF threat detection unit 112 (conveniently implemented by a digital receiver), the latter:

ㆍDetecting the presence of an RF threat based on RF signals received by the receiving antennas 111 and predefined RF threat-related library(s) 113;

ㆍIf an RF threat is detected,

- determine the respective type of detected RF threat based on the RF signals received by the receiving antennas 111 and the predefined RF threat-related library(s) 113,

- Estimate the arrival direction of each detected RF threat based on the RF signals received by the receiving antennas 111,

- Alert the control system 13 about detected RF threats, providing the control system 13 with the respective arrival type and respective arrival direction of the detected RF.

In this regard, the predefined RF threat-related library(s) 113 allows the RF threat detection unit 112 to detect the presence of the RF threat(s) of interest and detect the presence of the RF threat(s) of interest and One or more RF threats of interest (e.g. SAR sensors/systems, radar sensors/systems or more generally RF remote sensing sensors/systems) to be able to determine their respective type based on the RF signals. It is important to describe what contains (i.e. stores) information related to the system.

Preferably, the predefined RF threat-related library(s) 113 includes (i.e. stores) information and/or data, the information and/or data comprising:

· Relates to various types of RF threats of interest;

ㆍIndicates the respective operating parameters (e.g., frequency, pulse repetition interval (PRI), pulse width, agility, etc.) of the RF threats of interest.

Figure 5 shows a block diagram schematically illustrating the high-level functional architecture of the control system 13, which includes:

ㆍControl unit 131; and

ㆍContains one or more predefined RF jamming action related libraries 132, and the predefined RF jamming action related library(s) 132 can be conveniently stored in the internal memory of the control system 13. there is.

More specifically, when the control unit 131 detects an RF threat by the RF threat detection unit 112,

ㆍDetermine the RF jamming action to be performed on the detected RF threat based on the respective type determined by the RF threat detection unit 112 and the predefined RF jamming action related library(s) 132;

ㆍOperating the RF jamming means 12 so that the RF jamming means 12 performs a determined RF jamming action on the detected RF threat (in particular, the direction of arrival of the RF threat estimated by the RF threat detection unit 112) It is configured to provide the RF jamming means 12 with an appropriate command indicating .

In this regard, the predefined RF jamming action related library(s) 132, for each RF threat of interest inserted/marked/defined in the predefined RF threat library(s) 113, It is important to explain that it contains (i.e. stores) respective information related to one or more respective RF jamming operations to be performed against RF threats.

Preferably, the predefined RF jamming action related library(s) 132 is, for each RF threat of interest inserted/marked/defined in the predefined RF threat related library(s) 113, respectively. Contains (i.e. stores) the information and/or the respective data, and the respective information and/or the respective data,

· Relates to one or more respective RF jamming technologies (conveniently the most appropriate and effective jamming technologies) to be implemented against said RF threat of interest;

Indicates the respective operating parameters used to implement the respective RF jamming technology(s) for the RF threat of interest, wherein the respective operating parameters conveniently have the following characteristics:

- noise band to be used,

- the number of jamming pulses to be generated for each received SAR/radar/RF pulse,

- the amplitude modulation(s) to be used, and

- Relates to one or more of the frequency modulation(s) to be used.

FIG. 6 shows a block diagram schematically illustrating the high-level functional architecture of the RF jamming means 12 , which is capable of detecting and detecting the RF threat detection means 11 (in particular by the RF threat detection unit 112 ). operable by the control system 13 (in particular by the control unit 131) in the case of detection of RF threats,

ㆍPlural transceiver antennas 121 - The plurality of transceiver antennas are,

- Also provides the same elevation and azimuth angle coverage as the receiving antennas 111,

- Tracks detected RF threats (conveniently by receiving RF signals coming from the detected RF threats),

- configured to transmit RF jamming signals for said detected RF threat to perform a corresponding RF jamming action determined by the control system 13 (in particular by the control unit 131); and

ㆍComprising an RF jamming signal generating unit 122, the RF jamming signal generating unit 122 is preferably of the Digital Radio Frequency Memory (DRFM) type (conveniently, transceiver antennas ( After storing and processing the RF signals from a detected RF threat received by 121), generating jamming signals to be transmitted by the transceiver antennas 121 to perform the corresponding RF jamming action on the detected RF threat. It is configured to do so.

Conveniently, the transceiver antennas 121 are:

ㆍHigh gain; and

ㆍIt is intended to provide high capabilities (particularly in terms of agility, flexibility and accuracy) of pointing of receive and transmit beams, and thus of detected RF threats.

Preferably, the transceiver antennas 121 are Active Electronically Steered/Steerable Antennas (AESA) - sometimes also referred to as Active Electronically Scanned Arrays (AESA). It is manufactured.

Preferably, the jammer 1 comprises a mechanical pointing system configured and operable to change the elevation pointing of the receive antennas 111 and the transceiver antennas 121 to modify the elevation angle coverage of the jammer 1. or combined with it.

Conveniently, the mechanical pointing system changes the elevation pointing of the receive antennas 111 and the transceiver antennas 121 and thereby tilts the entire jammer 1 to modify the elevation angle coverage of the jammer 1. It is configured and operable to change.

Instead, with regard to the user interface means 2, the latter conveniently enables the user/operator to:

ㆍMonitoring and controlling the operation of the jammer (1);

• Define/set the elevation angle coverage of the jammer 1, i.e. the receive antennas 111 and the transceiver antennas 121 (specifically, by defining/setting the given minimum and maximum elevation angles described above);

ㆍDefine, program, set, modify, etc. predefined RF threat-related library(s) 113 and predefined RF jamming action-related library(s) 132;

ㆍConveniently configured to allow operating a mechanical pointing system to change/modify the elevation angle coverage of the jammer (1).

In the light of what has just been explained, it is also possible to define a jamming system comprising a jammer 1 and user interface means 2 (and, in the case of a mechanical pointing system external to the jammer 1, said mechanical pointing system).

Figure 7 shows an example of an embodiment of a jammer 1 for use on naval platforms to detect and jam satellite SAR signals.

In particular, in this example of embodiment, the transceiver antennas 121 dedicated to the transmission of jamming are realized by two pairs of AESAs 121A, 121B,

ㆍEach pair of AESA (121A, 121B) operates in its own frequency band;

• For each pair, two respective AESAs (121A or 121B) of the pair each provide azimuthal coverage of 90°, whereby each pair provides total azimuth coverage of 180°.

Additionally, the receiving antennas 111 dedicated to the detection of satellite SAR threats include multiple antenna groups providing overall azimuthal coverage of 180°, each group of antennas being of the type shown in Figure 4 and previously described. can be conveniently realized by three horn antennas (i.e., horn antennas 111A, 111B, and 111C).

Conveniently, a 45° polarizer can also be advantageously used.

Accordingly, by using a jamming system implemented according to the example shown in FIG. 7 and just described and comprising two jammers suitably installed/mounted relative to each other on one and the same maritime platforms, detection of satellite SAR threats and such For the delivery of jamming against threats, it is possible to obtain a total azimuthal coverage of 360° around the zenith axis of the jamming system.

In this regard, it is important to note that the examples of embodiments shown in Figure 7 and just described should not be interpreted as absolutely limiting, much less binding. In practice, the jammer 1 advantageously:

ㆍMaritime applications for naval or coastal installations; and

ㆍCan be advantageously used in land areas for fixed or mobile facilities.

In particular, depending on the type of mission of interest, the jammer 1 can be conveniently customized and expanded to meet different requirements (including but not limited to facilities) typical for different application scenarios. .

In the example shown in Figure 7, i.e. in the case of a satellite anti-SAR configuration of the jammer 1, the latter conveniently provides protection from low-Earth orbit satellite platforms.

In this case, the moment of illumination by the SAR sensor is unknown, and since the sensor in orbit is moving at very high speeds, a fast response is desirable.

Therefore, because SAR integrates signals over the observation period, jamming must operate from the beginning to the end of the lighting window to be as effective as possible, making it important to respond quickly.

Accordingly, in use, the RF threat detection means 11 intercepts pulses from the electromagnetic environment, recognizes pulses belonging to RF threats of possible interest (e.g. in the case of SAR threats) and roughly estimates the direction of arrival, It is then tasked with providing the expected direction of arrival to the control system 13 to alert the control system 13 and thereby activating the transmission of the obstruction via the RF jamming means 12 . Initially, it is convenient to prioritize jamming propagation speed over measurement/estimate accuracy of the direction of arrival of the RF threat. Then, during propagation of the jamming, a fine-tuning of the measurement/estimate of the direction of arrival can conveniently be performed, thereby adjusting the pointing accuracy of the RF jamming means 12 (in particular the respective transceiver antennas 121) and the power of the jamming delivered. You can maximize all levels.

This effect can also be felt to some extent in the case of contrast for avionics platforms. In particular, in the case of airborne sensors, the illumination time is often significantly longer, resulting in longer visibility time intervals than in the case of satellites. However, sometimes, for example when an airborne platform approaches a protected object, the useful time for effective transmission of the jamming is reduced and the situation is similar to that of satellites.

Additionally, there remains the issue of the process gain of imaging sensors, which in various usage scenarios is generally higher than that of “classical” sensors.

SAR waveforms typically consist of pulses modulated with a linear (chirp) frequency modulation (FM) with a rather wide bandwidth to have a range of resolution comparable to azimuth; This also imposes additional constraints on detection techniques beyond long distances.

The limitations that normally remain in these contexts are overcome by the jammer 1 thanks to the use of receiving antennas 111 dedicated to the detection of SAR signals, oriented to ensure coverage in the required elevation angle sector. Additionally, this can ensure coverage against other categories of RF threats, especially those originating from high elevation angles.

8 and 9 respectively show examples of satellite SAR images and corresponding SAR images acquired in the presence of jamming delivered by jammer 1 in the above-described satellite anti-SAR configuration.

From the foregoing disclosure, the many innovative features and countless technical advantages of the present invention are immediately apparent to those skilled in the art.

In particular, the jamming device according to the present invention includes two subsystems, namely,

• A receiving subsystem dedicated to the detection of threats that alerts in response to illumination by threats from unusual arrival altitude angles; and

• It is important to point out that it is based on the coordination of the jamming subsystem, which prohibits the extraction of sensitive information (e.g. image information or angular and distance coordinates of one or more targets, for example) operated by an enemy sensor.

Proper mechanical structure and proper orientation of the antenna optimize the ability of the jamming device to detect radar transmissions coming from these classes of sensors and maximize contrast effectiveness. The most appropriate countermeasures strategy as well as the characteristics of the threat are conveniently determined, modified and managed on a library-by-library basis as a function of the ongoing mission.

The architecture of the jamming device allows it to best meet particularly stringent mission requirements and for this reason, the device can be used not only for anti-SAR applications, but also for defense against diving threats or in any case with sub-zenith flight profiles and high motion It can be utilized to advantage through scientific evolution.

In addition, the architecture of the jamming device according to the invention provides tight integration between the two above-described subsystems and allows the use of state-of-the-art transmission and processing technologies, which not only ensures maximum effectiveness of the delivered contrast, but also provides It makes the architecture particularly responsive and flexible.

These characteristics are advantageous in all application contexts where the speed of response, the power involved and the effectiveness of the delivered countermeasures are fundamental.

The jamming device according to the invention emerges from the applicant's extensive experience with jamming radar systems, which require the use of panoramic receivers with high intercept probability, fast response and consistent jamming propagation.

The present invention can meet stringent electronic defense requirements for satellite SAR sensors, or more generally, against a wide range of airborne-type RF threats from high elevation angles (up to near-zenith profiles).

Additionally, the use of state-of-the-art DRFM devices, such as Applicant's devices, allows jamming devices to provide a wide range of possible nuisances and to synthesize effective nuisances very quickly.

Additionally, the jamming device according to the invention is characterized by a very flexible control structure.

More specifically, the subsystem dedicated to jamming transmission is:

ㆍActs in real time against RF threats to reduce processing losses at enemy sensors and thus increase the effectiveness of countermeasures;

ㆍOperates on a pulse basis to maintain consistency at each moment of radar sensor transmission;

ㆍBy operating in a modulation manner, the characteristics and thus the effect of jamming injected from the enemy receiver can be controlled.

Actually, this is:

• Increase in the effects of transmitted jamming and consequently suppression of the ability of enemy sensors to extract relevant information; and

ㆍTranslated into the ability to control the jamming distribution in the resulting image (SAR or more generally radar).

Currently known traditional maritime and land electronic defense systems are not designed to ensure adequate elevation angle coverage for defense against zenith or sub-zenith type satellite or airborne SAR threats. In practice, existing configurations of these systems typically guarantee an elevation angle coverage range of [-5°, +55°]. On the other hand, the jamming device according to the present invention can ensure coverage for high elevation angles, and even azimuth or quasi-azimuth angles. Furthermore, according to a preferred embodiment of the invention, the jamming device may advantageously comprise or be coupled to a mechanical pointing/tilting system capable of orienting the antenna or the entire jamming device in real time towards a fixed desired pointing direction throughout the mission. You can. This orientation is also successful when detecting and protecting against SAR threats deployed on avionics platforms operating close to this field of view.

Another configuration may conveniently include arranging the antennas so that the final pointing is quasi-orthogonal to ensure coverage of the sector at the ceiling, once the jamming device is properly tilted.

The set of technical features described above makes the use of the jamming device according to the invention particularly advantageous for jamming a wide range of radar or airborne RF threats with various flight profiles, as well as satellite and airborne SAR sensors, because: This is because it can meet the general requirements of both types of operating scenarios.

actually,

• In the case of defense against satellite SAR, the use of a jamming device according to the invention is advantageous because the device has a high responsiveness; This characteristic, together with the possibility of programming, modifying and therefore using various countermeasures techniques, ensures high operational efficiency of the device and its effectiveness to counter satellite SAR threats at all times and offsets the high processing gain of SAR receivers;

In the case of defense against airborne SARs (e.g. installed on aircraft, drones, etc.), the use of a jamming device according to the invention allows such a device to be programmed, modified and thus have a flexible architecture that allows the use of highly effective contrast techniques. It is advantageous because; This ensures that efficient electronic defense is delivered, since the possibility of detecting SAR-type threats is always guaranteed;

ㆍFor defense against airborne RF threats with zenith, sub-zenith profile or more generally high field of view, the use of jamming devices according to the invention allows such devices to have the ability to configure the field of view by means of a mechanical pointing system. This is advantageous because an appropriate configuration can always be obtained, such as ensuring coverage of zenith angle elevation sectors or sectors close to 90°; This ensures the delivery of efficient or effective electronic defense because:

- the ability to detect threats with zenith or near-zenith flight profiles is guaranteed,

- Fast response delivery is guaranteed,

- Because effective jamming techniques can be used.

Finally, the present invention makes it possible to equip naval or land platforms with an electronic defense system that is highly effective against satellite or airborne SAR threats and, more generally, against various types of airborne RF threats at high viewing angles. It is important to note once again that

In fact, the jamming device according to the present invention,

ㆍRequirements of different mission categories, e.g.

- satellite anti-SAR missions,

- Can be configured to meet anti-platform air missions,

- More generally, it can provide effective jamming (imaging or otherwise high process gain) of radars of airborne platforms at elevation angles up to zenith (depending on mission configuration);

ㆍEnsures rapid response to various types of threats, i.e.

- Provide a receiving subsystem specifically dedicated to the function of detecting threats of interest,

- It also integrates a jamming subsystem for delivery of jammers within the same device;

ㆍPreferably provided with a mechanical pointing system,

- Maximize or optimize elevation angle coverage,

- Optimize the transmitted jamming power;

ㆍHas high threat hunting capability and the ability to maximize delivered jamming power;

ㆍHas a very flexible control architecture.

In conclusion, although the invention described above has particularly referred to very specific embodiments, the invention is intended to be limited to these embodiments, including any variations, modifications or simplifications covered by the appended claims within their scope. It is important to note that this should not be the intention.

Claims (13)

A jamming device (1) for the protection of targets on the Earth's surface from radio frequency threats of space, satellite or air type, comprising:
The jamming device 1 is,
Radio frequency threat detection means (11);
radio frequency jamming means (12); and
Includes a control system (13),
The radio frequency threat detection means 11,
A plurality of receiving antennas 111;
radio frequency threat detection unit 112; and
Contains one or more predefined radiofrequency-threat-related libraries (113),
the receiving antennas 111 are configured to receive radio frequency signals having elevation angles of arrival that are greater than or equal to a given minimum elevation angle to provide elevation angle coverage of interest;
The radio frequency threat detection unit 112,
detect the presence of the radio frequency threat based on the radio frequency signals received by the receiving antennas (111) and the predefined radio frequency threat related library(s) (113);
If a radio frequency threat is detected,
Determine each type of the detected radio frequency threat based on the radio frequency signals received by the receiving antennas (111) and the predefined radio frequency threat related library(s) (113),
Estimating each direction of arrival of the detected radio frequency threat based on radio frequency signals received by the receiving antennas 111,
Alert the control system (13) about the detected radio frequency threats, providing the control system (13) with the respective types and respective coming directions of the detected radio frequency threats;
The predefined radio-frequency threat-related library(s) 113 allows the radio-frequency threat detection unit 112 to detect the presence of the radio-frequency threat(s) of interest and to detect the presence of the radio-frequency threat(s) of interest and to detect the presence of the radio-frequency threat(s) of interest. includes information related to one or more radio frequency threats of interest to determine the respective type of radio frequency threat(s) of interest based on the radio frequency signals;
The control system 13 is,
control unit 131; and
Contains one or more predefined radiofrequency-jamming-actions-related libraries (132),
The control unit 131, when a radio frequency threat is detected by the radio frequency threat detection unit 112,
Radio frequency jamming to be performed on the detected radio frequency threat, based on the respective type determined by the radio frequency threat detection unit 112 and the predefined radio frequency jamming action related library(s) 132. determine action;
the radio frequency jamming means (12) is configured to operate the radio frequency jamming means (12) to perform the determined radio frequency jamming action against the detected radio frequency threat;
The predefined radio frequency jamming action related library(s) 132 is configured to, for each radio frequency threat of interest inserted into the predefined radio frequency threat related library(s) 113, the radio frequency threat of interest. Contains respective information related to one or more respective radio frequency jamming operations to be performed on,
The radio frequency jamming means (12) is operable by the control unit (131) when a radio frequency threat is detected by the radio frequency threat detection unit (112),
A plurality of transceiver antennas 121 - The plurality of transceiver antennas are,
Also providing the elevation angle coverage of interest,
Track the detected radio frequency threats,
configured to transmit radio frequency jamming signals in response to the detected radio frequency threat to perform the radio frequency jamming action determined by the control unit (131); and
comprising a radio frequency jamming signal generating unit (122) configured to generate the radio frequency jamming signals to be transmitted by the transceiver antennas (121) in response to the detected radio frequency threat to perform the radio frequency jamming operation. Jamming device (1).
According to paragraph 1,
The receiving antennas (111) are configured to receive radio frequency signals having arrival elevation angles falling within a given elevation angle range defined by the given minimum elevation angle and the given maximum elevation angle that is greater than the given minimum elevation angle,
Jamming device, wherein the given elevation angle range corresponds to the elevation angle coverage of interest.
Jamming device according to claim 1 or 2, wherein the given minimum elevation angle is greater than or equal to 20°.
The jamming device of claim 2, wherein the given minimum elevation angle is comprised between 20° and 65° and the given maximum elevation angle is comprised between 40° and 90°.
According to any one of claims 1 to 4,
The receiving antennas 111 are configured to receive radio frequency signals having the elevation angles of arrival and azimuth angles of arrival ranging from 0° to 180° or 0° to 360°, whereby the receiving antennas 111 Provides azimuthal coverage of 180° or 360° centered on the zenith direction of the jamming device (1);
Transceiver antennas 121 are also configured to provide the azimuthal coverage.
The method of any one of claims 1 to 5, wherein the predefined radio frequency threat-related library(s) 113 comprises:
Associated with various types of radio frequency threats of interest;
Contains information and/or data indicative of respective operating parameters of the radio frequency threats of interest;
The predefined radio frequency jamming action related library(s) 132, for each radio frequency threat of interest inserted into the predefined radio frequency threat related library(s) 113,
associated with one or more respective radio frequency jamming technologies to be implemented against said radio frequency threat of interest;
A jamming device comprising respective information and/or respective data indicating respective operating parameters used to implement the respective radio frequency jamming technology(s) against the radio frequency threat of interest.
According to any one of paragraphs 1 and 6,
change the elevation pointing of the receive antennas 111 and the transceiver antennas 121 to modify the elevation angle coverage of interest;
or a mechanical pointing system operable to modify the elevation angle coverage of interest by changing the tilt of the entire jamming device 1 to change the elevation pointing of the receive antennas 111 and the transceiver antennas 121. Combined jamming device.
According to any one of claims 1 to 7,
The receiving antennas 111 are horn-type directional antennas;
The transceiver antennas 121 are active electronically steered/steerable high-gain antennas;
The radio frequency threat detection unit 112 is a digital receiver;
The radio frequency jamming signal generation unit 122 is a jamming device based on digital radio frequency memory (Digital Radio Frequency Memory) technology.
9. The method according to any one of claims 1 to 8, wherein the radio frequency threat detection means (11), the radio frequency jamming means (12) and the control system (13) consist of a single integrated device/device. Jamming device.
A jamming system for the protection of targets on the Earth's surface from radio frequency threats of space, satellite or airborne type, comprising:
One or more jamming devices (1) according to any one of claims 1 to 9; and
comprising user interface means (2), said user interface means (2) being connected to said jamming device(s) (1) and allowing a user/operator to:
Monitor and control the operation of the jamming device(s) (1),
Set the altitude angle coverage of interest of the jamming device(s) (1),
Configured to allow defining and modifying the predefined radio frequency threat related library(s) 113 and the predefined radio frequency jamming action related library(s) 132 of the jamming device(s) 1 A jamming system.
A jamming system for the protection of targets on the Earth's surface from radio frequency threats of space, satellite or airborne type, comprising two jamming devices (1) according to claim 5; Each jamming device 1 is configured to provide a respective azimuthal coverage of 180° around a respective zenith direction of the jamming device 1; The jamming devices (1) are arranged relative to each other so as to provide azimuthal coverage of 360° about the zenith axis of the jamming system as a whole.
A jamming system for the protection of targets on the Earth's surface from radio frequency threats of space, satellite or airborne type, comprising:
One or more jamming device(s) (1) according to claim 7;
In the case of a mechanical pointing system external to the jamming device(s) (1), it may also include the mechanical pointing system; and
comprising user interface means (2), said user interface means (2) being connected to said jamming device(s) (1) and allowing a user/operator to:
Monitor and control the operation of the jamming device(s) (1),
Set the altitude angle coverage of interest of the jamming device(s) (1),
Define and modify the predefined radio frequency threat related library(s) 113 and the predefined radio frequency jamming action related library(s) 132 of the jamming device(s) 1,
A jamming system, configured to allow operating the mechanical pointing system to modify the elevation angle coverage of interest of the jamming device(s) (1).
A fixed or mobile land or sea platform equipped with the jamming device (1) according to any one of claims 1 to 9 or the jamming system according to any one of claims 10 to 12.

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