An emitter unit, a receiver unit, a system and use of a system for an emulated radar system, and a method for emulating a radar system

Abstract

An emitter unit (10) for emulating a radar system. The emitter unit (10) comprises an emitter (15) configured to emit radar-like emissions in a defined sector of a radar detecting object (32), and an emitter control unit (20) connected to the emitter (15) and configured to control the radar-like emission. The radar detecting object is configured with a sensor (37) for sensing the radar-like emissions and a receiver control unit (40) connected to the sensor and configured to identify receipt of a predetermined emission signature corresponding to the emulated radar system. The emitter control unit is configured to control the emission from the emitter to the predetermined emission signature. The predetermined emission signature comprises at least information on a predetermined frequency.

Description

[0001] TITLE: An emitter unit, a receiver unit, a system and use of a system for an emulated radar system, and a method for emulating a radar system

[0002] Field of the invention

[0003] The present invention relates to emitter unit for emulating a radar system. The emitter unit comprises an emitter configured to emit radar-like emissions in a defined sector of a radar detecting object. The emitter unit further comprises an emitter control unit connected to the emitter and configured to control the radar-like emission.

[0004] The present invention further relates to receiver unit for detecting an emulated radar system. The receiver unit is configured to be located at a radar detecting object, such as a vessel, for example a combat airplane or a ship. The receiver unit comprises a sensor for detecting radar-like emissions and a receiver control unit connected to the sensor. The sensor is configured to be exposed to the radar-like emissions from the emitter unit.

[0005] The present invention further relates to a system for emulating a radar system comprising the emitter unit and the receiver unit. The present invention further relates to a method for emulating a radar system and use of the system comprising the emitter unit and the receiver unit.

[0006] Background of the invention

[0007] Defence radar systems are used for detecting objects, in particular military vessel, such as a combat airplane or a ship. The locations of the radar systems are unknown to an operator of the vessels. However, the vessels are configured with receivers for detecting exposure to such radar system. Upon detection of exposure from such radar system, an operator needs to take actions, such as to locate the position of the radar system. In order to prepare the operator for such situations, exercises are conducted. The exercise may involve using current existing defence radar systems or specific training emitter systems.

[0008] A problem with using existing defence radar systems is that the locations of the existing defence radar systems are usually already known to the operator of the vessel. Alternative, specific training emitter systems may be used for the exercises.

[0009] A problem with prior art training emitter systems is that they require extensive maintenance and dedicated technical personnel to operate. Prior art training emitter systems are based on a traveling-wave tube (TWT) technology, which is fragile and can break easily. TWT emitters are especially susceptible to shock and moisture, something that is hard to avoid in field conditions. A further problem with prior art training emitter systems is extensive maintenance and down time of the system. Flight hours for combat aircraft are costly, and faulty training emitter systems may require that the flight is repeated for concluding the exercise.

[0010] A further problem with prior art training emitter systems is that they are set to emit at a fixed frequency or a narrow frequency range due to technical limitations. In a real situation, the frequency of the radar system would be unknown to the operator of the radar detecting object. A further problem is that prior art training emitter systems needs to emit at an allowed available frequency range decided by the authorities, such as NKOM in Norway. The frequency range of existing defence radar systems is generally already occupied and it may therefore be necessary to select different frequency range for the emission that may involve further cost to the system.

[0011] Accordingly, it is desired to provide an alternative to prior art training emitter systems that is cost effective, flexible and reliable.

[0012] Summary of the invention

[0013] An object of the present invention is to provide an improved emitter unit for emulating a radar system. In a particular, a first object of the invention is to provide a cost- effective emitter unit for emulating a radar system. A further object of the invention is to provide an emitter unit for emulating a radar system that is flexible regarding the emitted frequency range. Yet another object of the invention is to provide an emitter unit for emulating a radar system that is reliable and that is simple to operate. The above objects are also applicable to a receiver unit for detecting an emulated radar system according to embodiments of the invention, and a system comprising the emitter unit and receiver unit of the invention.

[0014] The above objects are obtained by means of emitter unit for emulating a radar system. The emitter unit comprises an emitter configured to emit radar-like emissions in a defined sector of a radar detecting object, and an emitter control unit connected to the emitter and configured to control the radar-like emission, wherein the radar detecting object is configured with a sensor for sensing the radar-like emissions and a receiver control unit connected to the sensor and configured to identify receipt of a predetermined emission signature corresponding to the emulated radar system, wherein the emitter control unit further is configured to control the emission from the emitter to the predetermined emission signature, wherein the predetermined emission signature comprises at least information on a predetermined frequency.

[0015] By means of emitting radar-like emissions in a defined sector using the emitter and controlling the emission using the emitter control unit such that the emission is emitted with the predetermined emission signature, the emission is configured to be exposed to the sensor of the radar detecting object. The receiver control unit at the radar detecting object is configured, based on received information from the sensor and knowledge of the predetermined emission signature, to identify the radar-like emissions as an emulating a radar system. The identification comprises comparing the characteristics of the received radar-like emissions with knowledge of a predetermined emission signature corresponding to an emulating a radar system. In view of the identification of the emulating a radar system, the operator of the radar detecting object may take actions included in the exercise, such as geographically locating the emitter unit.

[0016] By means of emitting radar-like emissions comprising the predetermined emission signature the emission the power of the emission may be arranged lower compared to emissions from defence radar systems and prior art training emitter systems. It is thereby possible to emit the emission using emitters that are simpler than the emitters used in defence radar systems or prior art training emitter systems. Moreover, it is possible to use emitters that are not suffering from the disadvantages and limitation of traveling-wave tube (TWT) emitters used in prior art training emitter systems.

[0017] The term ‘predetermined emission signature’ is to be understood as an emission comprising specific characteristics corresponding to information that enables the receiver control unit at the radar detecting object to detect and recognize it as an emulated radar system. The predetermined emission signature comprises at least information on a predetermined frequency. However, it shall be understood that predetermined emission signature may involve further characteristics that facilitates the receiver control unit to detect and recognize it as an emulating radar system.

[0018] According to an embodiment of the invention, the emitter is configured to emit radarlike emissions with a frequency in the range of 0,5 - 40 GHz, preferably 8 - 12 GHz.

[0019] According to an embodiment of the invention, the emitter is configured to emit pulsed emissions, wherein the predetermined emission signature further comprises at least information on one of a predetermined pulse repetition interval and a predetermined pulse width.

[0020] The additional characteristics of the predetermined emission signature facilitates the receiver control unit to detect and recognize it as an emulating a radar system. Accordingly, the additional characteristics of the predetermined emission signature improves the robustness in which the emission from the emitter unit is detected and recognized as an emulated radar system.

[0021] According to an embodiment of the invention, the emitter is configured to emit two or more predetermined emission signatures, wherein the emitter control unit is configured to control the emitter to selectively emit the two or more predetermined emission signatures.

[0022] According to an embodiment of the invention, the emitter has a capacity of emitting radar-like emissions with an Effective Isotropic Radiated Power in the range of 800 - 3000 W EIRP, preferably 800 - 1500 W EIRP.

[0023] According to an embodiment of the invention, the emitter is configured to emit radarlike emissions with a beam having an angular width in the interval of 90 - 100 degrees.

[0024] According to an embodiment of the invention, the emitter unit comprises a support structure that encloses at least partly the emitter and the emitter control unit, wherein the support structure is configured with a visual appearance of a radar system. By means of the configuration of the support structure with visual appearance of a radar system, the visual location of the support structure as a radar system may be included in the exercise of detecting the emulated radar system. The above object of the invention is also obtained by means of receiver unit at a radar detecting object for detecting an emulated radar system. The receiver unit comprises a sensor for detecting radar-like emissions and a receiver control unit connected to the sensor, wherein the sensor is configured to be exposed to radarlike emissions from an emitter unit that is emitted according to a predetermined emission signature, wherein the predetermined emission signature comprises at least information on a predetermined frequency, wherein the receiver control unit is configured to identify the predetermined emission signature as a emulated radar system by comparing at least the frequency of the radar-like emissions exposed to the sensor with the frequency of the predetermined emission signature and upon correspondence to generate and transmit information indicating the identification of the emulated radar system.

[0025] The radar-like emissions comprising the predetermined emission signature from the emitter device is configured to be received at the sensor. Information on the radarlike emissions exposed to the sensor is configured to be transmitted to the receiver control unit. The receiver control unit is configured with the knowledge of the characteristics of the predetermined emission signature. The receiver control unit is configured to detect and recognize the received radar-like emissions as the emulated radar system by comparing at least the frequency of the radar-like emissions exposed to the sensor with the frequency of the predetermined emission signature. In case the received radar-like emissions comprises the characteristics specific to the predetermined emission signature, the receiver control unit is configured to generate and transmit information indicating the identification of the emulated radar system to an operator of the radar detecting object. The operator of the radar detecting object may thereafter take actions included in the exercise, such as geographically locating the emitter unit.

[0026] The receiver unit of the invention has the advantages of enabling simple sensors to be used. The receiver unit may be in the form of an additional unit that is connected to the radar detecting object.

[0027] According to an embodiment of the invention, the comparison of the received emissions with the characteristics specific to the predetermined emission signature is performed by means of that the receiver control unit is comparing the characteristics of the received emission with a list of one or more predetermined emission signatures. The list may for example be comprised by a database in a memory unit connected to the receiver control unit.

[0028] According to an embodiment of the invention, the predetermined emission signature further comprises at least information on one of a predetermined pulse repetition interval and a predetermined pulse width, wherein the receiver control unit further is configured to identify said predetermined emission signature as an emulated radar system by comparing also at least one of the predetermined pulse repetition interval and the predetermined pulse width.

[0029] According to an embodiment of the invention, the receiver unit further comprises notification means connected to the receiver control unit and configured to, up on receipt of said information, to notify identification of the emulated radar system.

[0030] According to an embodiment of the invention, the notification means comprises at least one of a display screen, loudspeaker and an indicator light.

[0031] According to an embodiment of the invention, the receiver control unit is configured to determine the range and position of the emitter unit based on the receipt of the predetermined emission signature, and wherein the receiver unit comprises display means configured to the display the determine range and position of the emitter unit from the receiver unit.

[0032] The above object of the invention is also obtained a system comprising an emitter unit according to any of above embodiments and a receiver unit according to any of above embodiments.

[0033] The above object of the invention is further obtained by a method for emulating a radar system. The method comprises the steps of:

[0034] - emitting radar-like emissions with a predetermined emission signature towards an expected location of a radar detecting object, wherein the predetermined emission signature comprising at least information on a predetermined frequency,

[0035] - receiving exposure of said predetermined emission signature at the radar detecting object,

[0036] - identifying said predetermined emission signature as an emulated radar system by comparing at least the frequency of the received radar-like emissions with the frequency of the predetermined emission signature, and - upon correspondence, generating and transmit information indicating the identification of said emulated radar system.

[0037] According to an embodiment of the invention, the predetermined emission signature further comprises at least information on one of a predetermined pulse repetition interval and a predetermined pulse width, wherein the step of identify the predetermined emission signature as an emulated radar system further comprises comparing at least one of the received predetermined pulse repetition interval and the received predetermined pulse width with the predetermined emission signature.

[0038] According to an embodiment of the invention, the radar detecting object comprises notification mean, wherein the method further comprises

[0039] - upon receipt of information indicating the identification of the emulated radar system, indicating identification of said emulated radar system to an operator of the radar detecting object by means of the notification mean.

[0040] The above object of the invention is further obtained by means of use of a system for emulating a radar system according to any of above embodiments.

[0041] Description of the figures

[0042] Embodiments of the present invention will now be described, by way of example only, with reference to the following figures, wherein:

[0043] Figure 1 discloses a schematic view of a system comprising an emitter unit and a receiver unit according to an embodiment of the invention, and

[0044] Figure 2 discloses a flow chart of a method for emulating a radar system according to an embodiment of the invention.

[0045] Description of preferred embodiments of the invention

[0046] With reference to fig. 1 , a schematic view of a system 1 for emulating a radar system according to an embodiment of the invention is disclosed. The system 1 comprises an emitter unit 10 and a receiver unit 30.

[0047] The emitter unit 10 is for example arranged in a support structure 12 located on the ground in the field. The support structure 12 is holding the component of the emitter unit 10. The support structure 12 is preferably configured with visual appearance of a radar system. Thereby, the visual location of the emitter unit 10 may be included in the exercise of detecting the emulated radar system.

[0048] The receiver unit 30 is arranged at a radar detecting object 32, for example a combat airplane or a ship. In the disclosed embodiment, the radar detecting object 32 is schematic indicated as an airplane.

[0049] The radar detecting object 32 is located at a distance from the emitter unit 10. The radar detecting object 32 holds the component of the receiver unit 30.

[0050] The emitter unit 10 comprises an emitter 15 configured to generate radar-like emissions in a defined sector towards an unknown location of the radar detecting object 32. The emitter unit 10 comprise an antenna 17 for emitting the radar-like emissions into the air.

[0051] The emitter 10 further comprises an emitter control unit 20 connected to the emitter 15 and configured to control the radar-like emission from the emitter 15. The emitter control unit 20 is configured to control the radar-like emission from the emitter 15 such that emitter 15 emits radar-like emission comprising a predetermined emission signature.

[0052] The predetermined emission signature comprises pre-set characteristics of the radar-like emission. The predetermined emission signature comprises at least information on a predetermined frequency. The predetermined emission signature preferably comprises further characteristic that enables the emitted radar-like emission to be detected and recognized by the receiver unit 30 at the radar detecting object 32. According to an embodiment, the predetermined emission signature further comprises information on at least one of a predetermined pulse repetition interval and a predetermined pulse width.

[0053] The emitter 10 is preferably configured to emit radar-like emissions with a frequency in the range of 0,5 - 40 GHz, preferably 8 - 12 GHz. Preferably, the emitter 10 has a capacity of emitting radar-like emissions with an Effective Isotropic Radiated Power in the range of 800 - 3000 W EIRP, preferably 800 - 1500 W EIRP. The emitted radar-like emission is preferably emitted with a beam having an angular width in the interval of 90 - 100 degrees. According to an embodiment of the invention, the emitter unit 10 is configured to emit radar-like emission with two or more different predetermined emission signatures. In a preferred embodiment the emitter unit 10 further comprise an emitter memory unit 22 connected to the emitter control unit 20. The emitter memory unit 22 comprises information on the two or more different predetermined emission signatures. The emitter control unit 20 is configured to collect information on a specific predetermined emission signature from the emitter memory unit 22 and on basis thereof control the emitter 15 to emit radar-like emissions comprising the specific predetermined emission signature.

[0054] The receiver unit 30 comprise a sensor 37 and a receiver control unit 40. The sensor 37 is configured to be exposed to the radar-like emissions from the emitter unit 10 that has been emitted according to the predetermined emission signature. The receiver control unit 40 is connected to the sensor 37. The receiver control unit 40 is configured to receive information on exposed radar-like emissions from the sensor 37.

[0055] The receiver control unit 40 possess the knowledge of the characteristics of the predetermined emission signature. The receiver control unit 40 is configured to identify the predetermined emission signature as an emulated radar system by comparing at least the frequency of the radar-like emissions exposed to the sensor 37 with the frequency of the predetermined emission signature. In case there is an agreement between the characteristics, in this case the frequency, the receiver control unit 40 is configured to generate and transmit information indicating the identification of the emulated radar system.

[0056] According to an embodiment, the comparison of the frequency of the received radarlike emission and the known frequency of the predetermined emission signature relates to comparing if the frequency of the received radar-like emissions falls within a frequency interval of the predetermined emission signature.

[0057] According to an embodiment of the invention, the receiver unit 30 further comprises a receiver memory unit 42 connected to the receiver control unit 40. The receiver memory unit 42 is configured to comprise information on two or more different predetermined emission signatures. The receiver control unit 40 is configured to collect information on a list comprising the two or more of predetermined emission signatures from the receiver memory unit 42 and on basis thereof compare if the received radar-like corresponds with any of the characteristics in the list.

[0058] In the disclosed embodiment, the receiver unit 30 further comprises notification means 44 connected to the receiver control unit 42 and configured, up on receipt of transmit information indicating the identification of the emulated radar system, to notify identification of the emulated radar system. The notification means 44 preferably comprises at least one of a display screen, loudspeaker and an indicator light.

[0059] With reference to fig. 2 a flow chart of a method for emulating a radar system according to an embodiment of the invention is disclosed.

[0060] The method comprises, in a step 110, the step of emitting radar-like emissions with a predetermined emission signature towards an overall expected location of the radar detecting object 32. The predetermined emission signature is configured according to any of the embodiment discussed above.

[0061] In a step 120, the method comprises receiving exposure of the predetermined emission signature at the radar detecting object 32. The step relates to the exposure of the sensor 37 in the receiver unit 30 and transmitting information on the exposure to the receiver control unit 40.

[0062] In a step 130, the method comprises identifying the predetermined emission signature as an emulated radar system by comparing at least the frequency of the received radar-like emissions with the frequency of the predetermined emission signature. The step relates to comparing the known characteristics of the predetermined emission signature with the characteristics of the received emissions. The step of identifying is preferably based on known information on one of a predetermined pulse repetition interval and a predetermined pulse width. The comparison is performed by means of the receiver control unit 40 according to any of the embodiment discussed above.

[0063] In a step 140, the method comprises generating and transmit information indicating the identification of the emulated radar system upon correspondence of the characteristics with the predetermined emission signature. The step of indicating the identification of the emulated radar system preferably involves activating notification means 44, such as by means of at least one of display screen, loudspeaker and an indicator light.

[0064] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

Claims

Claims1. An emitter unit (10) for emulating a radar system, where the emitter unit (10) comprises an emitter (15) configured to emit radar-like emissions in a defined sector of a radar detecting object (32), where the emitter unit (10) is characterized by further comprising an emitter control unit (20) connected to the emitter (15) and configured to control the radar-like emission, wherein the radar detecting object (32) is configured with a sensor (37) for sensing the radar-like emissions and a receiver control unit (40) connected to the sensor (37) and configured to identify receipt of a predetermined emission signature corresponding to the emulated radar system, wherein the emitter control unit (20) further is configured to control the emission from the emitter (15) to said predetermined emission signature, wherein the predetermined emission signature comprises at least information on a predetermined frequency.

2. The emitter unit (10) according to claim 1 , wherein the emitter (15) is configured to emit radar-like emissions with a frequency in the range of 0,5 - 40 GHz, preferably 8 - 12 GHz.

3. The emitter unit (10) according to any of claim 1 and 2, wherein the emitter (15) is configured to emit pulsed emissions, wherein the predetermined emission signature further comprises at least information on one of a predetermined pulse repetition interval and a predetermined pulse width.

4. The emitter unit (10) according to any of the previous claims, wherein the emitter (15) is configured to emit two or more predetermined emission signatures, wherein the emitter control unit (20) is configured to control the emitter (15) to selectively emit said two or more predetermined emission signatures.

5. The emitter unit (10) according to any of the previous claims, wherein the emitter (15) has a capacity of emitting radar-like emissions with an Effective Isotropic Radiated Power in the range of in the range of 800 - 3000 W EIRP, preferably 800 - 1500 W EIRP .

6. The emitter unit (10) according to any of the previous claims, wherein the emitter (15) is configured to emit radar-like emissions with a beam having an angular width in the interval of 90 - 100 degrees.

7. The emitter unit (10) according to any of the previous claims, wherein the emitter unit (10) comprises a support structure (12) that encloses at least partly the emitter (15) and the emitter control unit (20), wherein the support structure (12) is configured with a visual appearance of a radar system.8.A receiver unit (30) at a radar detecting object (32) for detecting an emulated radar system, where the receiver unit (30) is characterized by comprising a sensor (37) for detecting radar-like emissions and a receiver control unit (40) connected to the sensor (37), wherein the sensor (37) is configured to be exposed to radar-like emissions from an emitter unit (10) that is emitted according to a predetermined emission signature, wherein the predetermined emission signature comprises at least information on a predetermined frequency, wherein the receiver control unit (40) is configured to identify said predetermined emission signature as a emulated radar system by comparing at least the frequency of the radar-like emissions exposed to the sensor (37) with the frequency of the predetermined emission signature and upon correspondence to generate and transmit information indicating the identification of said emulated radar system.

9. The receiver unit (30) according to claim 8, wherein the predetermined emission signature further comprises at least information on one of a predetermined pulse repetition interval and a predetermined pulse width, wherein the receiver control unit (40) further is configured to identify said predetermined emission signature as an emulated radar system by comparing also at least one of the predetermined pulse repetition interval and the predetermined pulse width.

10. The receiver unit (30) according to claim 9, wherein the receiver unit (30) further comprises notification means (44) connected to the receiver control unit (40) and configured to, up on receipt of said information, to notify identification of the emulated radar system.

11. The receiver unit (30) according to claim 10, wherein the notification means (44) comprises a display screen.

12. The receiver unit (30) according to any of claim 8-11 , wherein the receiver control unit (40) is configured to determine the range and position of the emitter unit (10) based on the receipt of the predetermined emission signature, and wherein thereceiver unit (30) comprises display means configured to the display the determine range and position of the emitter unit (10) from the receiver unit (30).13.A system (1) for emulating a radar system, wherein the system (1) comprises an emitter unit (10) according to any of claim 1-7 and a receiver unit (30) according to any of claim 8-12.14.A method for emulating a radar system, wherein the method is characterized by comprising the steps of:- emitting radar-like emissions with a predetermined emission signature towards an expected location of a radar detecting object (32), wherein the predetermined emission signature comprising at least information on a predetermined frequency,- receiving exposure of said predetermined emission signature at the radar detecting object (32),- identifying said predetermined emission signature as an emulated radar system by comparing at least the frequency of the received radar-like emissions with the frequency of the predetermined emission signature, and- upon correspondence, generating and transmit information indicating the identification of said emulated radar system.

15. The method according to claim 14, wherein the predetermined emission signature further comprises at least information on one of a predetermined pulse repetition interval and a predetermined pulse width, wherein the step of identify said predetermined emission signature as an emulated radar system further comprises comparing at least one of the received predetermined pulse repetition interval and the received predetermined pulse width with the predetermined emission signature.

16. The method according to any of claim 14 and 15, wherein the radar detecting object (32) comprises notification mean, wherein the method further comprises- upon receipt of information indicating the identification of the emulated radar system, indicating identification of said emulated radar system to an operator of the radar detecting object (32) by means of the notification mean.

17. Use of a system (1) for emulating a radar system according to claim 13.

Images