METHOD FOR PROTECTING AN OBJECT FROM A RADAR-GUIDED MISSILE

Abstract

The invention relates to a method for protecting an object, in particular a land vehicle or watercraft, in particular a ship, from of a radar-guided missile by deploying and using an active offboard reflector, which is arranged at a decoy and comprises at least one receiving antenna and at least one transmitting antenna, wherein a radar signal transmitted by the radar-guided missile is picked up and is returned to the missile as an amplified signal in the previously ascertained opposite direction of reception; the invention proposes carrying out the method by deploying a plurality of flying drones, each having at least one active offboard reflector, and positioning the drones relative to one another in space in such a way that the active offboard reflectors thereof act as individual scattering centers and the signals therefrom that are returned to the missile collectively produce a radar scatter pattern that simulates the object to be protected.

Claims

1. A method for protecting an objectin particular, a land vehicle or watercraft, and in particular a shipfrom a radar-guided missile, by deploying and using an active offboard reflector which is arranged at a decoy and comprises at least one receiving antenna and at least one transmitting antenna, wherein a radar signal transmitted by the radar-guided missile is picked up and returned to the missile as an amplified signal in the previously ascertained opposite direction of reception, wherein, to carry out the method, a plurality of flying drones are deployed, each having at least one active offboard reflector, and the drones are positioned relative to one another in space in such a way that the active offboard reflectors thereof act as individual scattering centers, and the signals therefrom that are returned to the missile collectively produce a radar scatter pattern that simulates the object to be protected.

2. The method according to claim 1, wherein the direction of reception of the radar signal and thus a direction of approach of the radar-guided missile are ascertained by means of the receiving antennas and/or by means of an additional sensor.

3. The method according to claim 1, wherein a direction of reception of a radar signal and/or a direction of approach of the radar-guided missile is ascertained by providing and using a plurality of receiving antennas at a dronein particular, in the form of an array-like arrangement of receiving antennas, in particular, in the form of a van-Atta-array of receiving antennas, and in particular, by means of phase comparison of a radar wave received in several receiving antennas.

4. The method according to claim 1, wherein the drones, before their deployment, are arranged or carried along on the object to be protected or on an accompanying vehicle.

5. The method according to claim 1, wherein the drones become airborne for their flying deployment starting from the object to be protected or starting from an accompanying vehicle carrying the drones, and in particular are brought into the air by means of a throwing device.

6. The method according to claim 1, wherein the drones are brought into the air by means of an electronically controlled throwing device for their flight deployment in such a way that the direction, speed, and/or distance of the movement relative to the object to be protected are ascertained taking into account and as a function of a previously ascertained direction of approach, and in particular further parameters of the incoming radar-guided missile.

7. The method according to claim 6, wherein the drones are brought into the air by means of the electronically controlled throwing device according to a previously calculated decoy pattern.

8. The method according to claim 1, wherein, for a respective drone, its current actual position is ascertained relative to its starting position on the object to be protected or on the accompanying vehicle and is compared to a previously calculated reference position, and in that a respective flight drive mechanism of the drone is controlled by means of an electronic flight drive control device such that the drone assumes the previously calculated reference position.

9. The method according to claim 8, wherein, for a respective drone, its current actual position is ascertained absolutely and/or relative to its starting position by means of GPS or preferably by means of an acceleration sensor system.

10. The method according to claim 1, wherein a distance control is carried out between the drones, and in that the drones for this purpose in particular communicate, i.e., exchange bidirectional information.

11. The method according to claim 1, wherein the plurality of drones are moved according to a previously predetermined or calculated swarm speed.

12. A protection system for carrying out the method according to claim 1, comprising a decoy and at least one active offboard reflector, which is arranged at the decoy and has at least one receiving antenna and at least one transmitting antenna, as well as a device for amplifying a radar signal transmitted by the radar-guided missile and received by the receiving antenna, and a device for controlling the transmitting antenna for transmitting the amplified radar signal in the opposite direction of reception back to the incoming missile, a device for ascertaining missile data, and in particular for ascertaining the direction of reception of the previously transmitted radar signal received from the missile, wherein the protection system further comprises a plurality of drones which collectively form the decoy, wherein at least some and preferably all of the drones each have at least one active offboard reflector, in that the drones have flight drive devices and electronic programmable control devices interacting therewith that are configured to arrange the drones in three-dimensional space and relative to one another according to a predetermined or previously calculated decoy pattern corresponding to the object to be protected, so that the drones and their active offboard reflectors act as individual scattering centers and collectively produce a radar scatter pattern that simulates the object to be protected.

13. The protection system according to claim 12, wherein an electronically controlled throwing device which can be aligned in azimuth and elevation, by means of which the plurality of drones are brought into the air for their flight deployment, and in particular are shot into the air.

14. The protection system according to claim 12, wherein a device is provided for ascertaining data about the movement state of the object to be protected.

15. The protection system according to claim 12, wherein a device for selecting or calculating a decoy pattern is provided as a function of the ascertainment of missile data and/or data about the movement state of the object to be protectedin particular, as a function of the ascertained type of the missile, as a function of a direction of approach of the missile, and/or as a function of the relative orientation of the object to be protected with respect to the direction of approach of the missile.

16. The protection system according to claim 12, wherein a device is provided at a drone for ascertaining a direction of reception of a radar signal and/or a direction of approach of the radar-guided missilein particular, by a plurality of receiving antennas, and in particular in the form of an array-like arrangement of receiving antennasin particular in the form of a van-Atta-array of receiving antennas.

17. The protection system according to claim 12, wherein, for a respective drone, a device for determining its current actual positionin particular, relative to its initial positionand for comparison with its reference position according to the decoy pattern to be formed is provided.

18. The protection system according to claim 17, wherein the device for determining the actual position is GPS-based or designed based upon an acceleration sensor system.

19. The protection system according to claim 12, wherein the drones have distance measuring devices in order to be able to ascertain an actual distance from at least one adjacently-flying drone, and in that the flight drive control devices of the drones are designed to control the flight drive device as a function of this actual distance in such a way that a predetermined target distance is achieved.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In the drawings:

[0041] FIG. 1 is a schematic representation, not to scale, of a threat situation due to the approach of a radar-guided missile towards an object in the form of a ship;

[0042] FIG. 2 is a schematic representation of the deployment of a decoy directly following a detection of the threat situation according to FIG. 1;

[0043] FIG. 3 shows the schematic indication of the positioning or arrangement of drones with active offboard reflectors as individual scattering centers for simulating the object to be protected, which is also shown;

[0044] FIG. 4 shows the object to be protected and, at a spatial distance therefrom, the spatial arrangement of drones with active offboard reflectors in a drone swarm for forming a decoy;

[0045] FIG. 5 is a schematic representation of an active offboard reflector and further components of a respective drone; and

[0046] FIG. 6 is a schematic representation of components of a protection system on board the object to be protected.

DETAILED DESCRIPTION

[0047] A method according to the invention for protecting an object from a radar-guided missile and a protection system according to the invention related thereto will be explained with reference to the figures.

[0048] FIG. 1 indicates a threat situation in which an object 2 to be protected in the form of a seagoing ship is located in the range of influence of an incoming radar-guided missile 4. The missile 4 transmits a radar signal in the form of a wide radar lobe in the approximate direction of the genuine target to be hit. It is designed to receive a radar signal reflected from a genuine target and to carry out a radar-guided target guidance to the source of the reflection and thus to arrive at the genuine target.

[0049] If this threat situation has been recognized as such on the object 2 to be protected, a decoy 6, which is still to be explained in more detail, can be deployed as indicated in FIG. 2, which decoy, by means of active offboard reflectors 8 provided on the decoy 6, can receive, amplify, and transmit back to the missile 4 the radar signal transmitted from the missile 4, so that the missile 4 does not lock onto the object 2 to be protected, but instead executes its homing control or guidance in the direction of the decoy 6.

[0050] In order to detect the threat situation, a device 10 for detecting an incoming missile and for ascertaining missile datain particular, for ascertaining a direction of reception 12 of the radar signal transmitted by the missile 4is provided on the object 2 to be protected. If the threat situation has been recognized as such and, preferably, sufficient missile data could also be ascertained, a defense or protection strategy suitable for this situation is selected and immediately implemented, with access to a central computer 14 of the object 2 and/or to a device or computing unit 16 of the protection system. The central computer 14 or this device 16 is designed to select or calculate a protection strategy and a decoy pattern and to implement them.

[0051] For this purpose, a plurality of drones 18 are brought into the air according to the invention in such a way that the drones 18 are arranged relative to one another in accordance with a selected or calculated decoy pattern and are brought to a distance from the object 2 to be protected, so that they form a drone swarm 20 corresponding to the selected or predetermined decoy pattern, which pattern is schematically indicated in FIG. 2. For this purpose, the drones 18 can be launched on board the object 2 to be protected by means of a throwing device 22, which can be adjusted in azimuth and elevation, in order to form the drone swarm 20 as the distance from the object 2 to be protected increases. The throwing device 22 is preferably electronically controlled and receives its control commands preferably from the aforementioned computing unit 16 on the object 2 to be protected or the protection system. In this case, further parameters from a device 24 for ascertaining or providing datain particular, on the movement state of the object 2 to be protected, on wind, or on seagoing conditionscan also be taken into account in the computing unit 16. This is indicated in FIG. 6. The throwing device 22 is controlled in such a way that the drones 18 reach the intended position in space and within the drone swarm 14 as quickly as possible to form the decoy 6.

[0052] In the present case, the term, drone 18, is understood to mean an unmanned, autonomously-flying aircraft, e.g., in the form of a missile with a helicopter drive, and in particular a hexacopter drive, i.e., with a flight drive mechanism 30 and with an electronic programmable control device 32 interacting therewith. The drones 18 and their flight drive mechanisms 30 and control devices 32 are configured and designed to arrange the drones 18 in three-dimensional space and relative to one another according to a decoy pattern that corresponds to the object 2 to be protected. The arrangement of the drones 18 within the drone swarm 20 thus forms the aforementioned decoy pattern, whereby the decoy 6 is formed.

[0053] Each drone 18 preferably has an active offboard reflector 8, the components of which are indicated schematically in FIG. 2 and in FIG. 5. It comprises in each case at least one schematically indicated receiving antenna 34 and at least one transmitting antenna 36 and an intermediately connected device 38 for amplifying the received radar signal and a device 40 for controlling the transmitting antenna 36 for transmitting the amplified radar signal in the opposite direction of reception 12 back to the incoming missile 4.

[0054] FIGS. 3 and 4 illustrate the selection of a suitable decoy pattern in the form of a decoy structure or decoy assembly of the drones 18 forming the decoy 6 in the form of their arrangement relative to one another within the drone swarm 20. FIG. 3 schematically shows an object 2 to be protected in the form of a ship. Each three-dimensionally emitting object does not have a single dispersion center, but, rather, its radar dispersion pattern, often also referred to as radar signature, will transmit a strong radar echo from different regions of the object, as a function of their suitability, in the opposite direction of reception. For example, areas of a ship which are further away from the surface of the water in sea travel, such as a bridge structure or the smokestack, contribute more strongly to the radar echo than regions located close to the water surface. Furthermore, obliquely-inclined planar regions also contribute to a lesser extent than ideally rectangular nested structures, which favor the reflection of incident radar radiation in the opposite direction of incidence. There is therefore the possibility of arranging a plurality of drones with their active offboard reflectors 8 according to the spatial projection and the assumed contribution of significant dispersion centers of the object 2 to be protected. Where a strong radar echo is naturally to be expected on the object to be protected, an actively reflective drone 18 is therefore arranged on the decoy 6 in the form of the drone swarm 14. For example, in regions of highest reflection contribution, such as the bridge region or smokestack, several drones can be arranged at a lesser distance from one another, i.e., in a higher drone density, according to the selected decoy pattern, than in regions close to the water at the bow or rear of the ship. FIGS. 3 and 4, meanwhile, are intended to illustrate only in a schematic manner the arrangement of drones 18 corresponding to the specific type of characteristic of the object 2 to be protected. In this way, according to the invention, a reflected radar signal, which is reflected back to the transmitting hostile missile 4, will have a large correspondence to an actually expected radar dispersion pattern of an intended genuine targetfor example, in the form of a ship. The distinction between decoy and genuine target is thereby made more difficult according to the invention.

[0055] Finally, as already mentioned, FIG. 5 schematically illustrates the components of a respective drone 18. An arrangement of several receiving antennas 34 in an array form, and in particular in the form of a van-Atta-array of a drone 18, can form part of a device 46 for ascertaining the direction of reception 12 of the radar signal transmitted and received by the missile. This direction information is made available to the flight drive control device 32 of the drones 18, and control commands are provided to the flight drive mechanism 30 by means of the flight drive control device 32 in order to align the drone 18 and its active offboard reflector 8 or its transmitting antenna 36 for the best possible reception reflection and back reflection in the opposite direction of reception.

[0056] Furthermore, a respective drone 18 comprises a device 50 for ascertaining its current actual position. This device 50 schematically indicated in FIG. 5 can be GPS-based, or it can be designed, based upon an acceleration sensor system, with, in general, several acceleration and/or rotation rate sensors, with the latter being preferred. The flight drive control device 32 can then determine by the reference/actual comparison whether the drone 18 is located at its reference position within the drone swarm 20. If this is not the case, a storage control method can be executed by outputting corresponding control commands to the flight drive device 30.

[0057] Furthermore, a distance measuring device 52 is indicated in FIG. 5, by means of which distance information for adjacently-flying drones is preferably ascertained and can be given to the flight drive control device 32.

[0058] Overall, by means of the better simulation according to the invention of an object 2 to be protected with the decoy 6, it is possible via several active offboard reflectors 8 carried along in a drone swarm 20 to realize a more effective protection of the object 2 from an incoming radar-guided missile.