A method, device, electronic device and storage medium for over-the-horizon target recognition

Abstract

The present application provides a method, device, electronic device and storage medium for over-the-horizon target recognition, which relates to the field of radar system target recognition. The method is applied to the interrogation end and the response end of the radar system, including: the interrogation end generates an interrogation signal based on interrogation information transmitted from the outside, and transmits the interrogation signal to a tropospheric scatter channel; the response end receives the interrogation signal from the tropospheric scatter channel, and obtains the interrogation information based on the interrogation signal; the response end generates response information based on the interrogation information, and generates a response signal based on the response information, and transmits the response signal to the tropospheric scatter channel; the interrogation end receives the signal transmitted from the tropospheric scatter channel, and obtains the response information based on the received signal. The technical solution of the present application can realize over-the-horizon target recognition, with efficient recognition process and accurate recognition results.

Description

Technical Field

[0001] The present application relates to the technical field of radar system target recognition, and in particular to a method, device, electronic device and storage medium for over-the-horizon target recognition. Background Art

[0002] The target recognition system based on the working principle of secondary radar has become the main means for countries around the world to achieve target recognition. After receiving the recognition command from the superior system, the interrogation end of the secondary radar generates interrogation information that is radiated in the specified direction after being coded, modulated, and amplified; after receiving the interrogation signal, the response end analyzes the interrogation information through the opposite process, and the response information generated based on the interrogation information is radiated omnidirectionally after being coded, modulated, and amplified; after receiving the response signal, the interrogation end analyzes the response information through the opposite process, completes the target recognition and information exchange work, and reports the results to the superior system.

[0003] As a blue territory, the ocean has always been a key deployment area for national defense, and the detection and identification of over-the-horizon targets at sea is also of utmost importance. Due to the existence of the earth's curvature and the fact that the sea surface environment is not conducive to the propagation of electromagnetic waves, the existing over-the-horizon target detection and identification methods cannot be applied to marine identification. Therefore, there is an urgent need to provide a technical means for over-the-horizon target identification at sea. Summary of the invention

[0004] The embodiments of the present application provide a method, device, electronic device and storage medium for over-the-horizon target recognition to solve the problem of the current lack of over-the-horizon target recognition means at sea.

[0005] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0006] According to a first aspect of an embodiment of the present application, a method for over-the-horizon target recognition is provided, which is applied to an interrogation end and a response end of a radar system, comprising:

[0007] The interrogation end generates an interrogation signal based on interrogation information transmitted from the outside, and transmits the interrogation signal to a tropospheric scatter channel;

[0008] The responding end receives the inquiry signal from the tropospheric scatter channel, and obtains the inquiry information based on the inquiry signal;

[0009] The responding end generates response information based on the inquiry information, generates a response signal based on the response information, and transmits the response signal to the tropospheric scatter channel;

[0010] The interrogation end receives the signal transmitted from the troposcatter channel, and obtains the response information based on the received signal.

[0011] In some embodiments of the present application, based on the above solution, the query end generates an inquiry signal based on the inquiry information transmitted from the outside, including:

[0012] The inquiry end first performs encoding, spread spectrum and MSK modulation processing on the inquiry information; then replicates the processed signal and successively combines it with the LFM signal to obtain a composite signal; finally, time diversity is performed on the composite signal to obtain the inquiry signal.

[0013] In some embodiments of the present application, based on the above solution, obtaining the inquiry information based on the inquiry signal includes:

[0014] The responding end performs down-conversion processing, channel equalization processing, diversity combining processing, demodulation and despreading processing, and decoding processing on the received inquiry signal to obtain the inquiry information.

[0015] In some embodiments of the present application, based on the above solution, the channel equalization processing includes:

[0016] The MMSE principle is used to equalize the channel and obtain the frequency domain equalization coefficient of the MMSE equalization algorithm;

[0017] Perform inverse Fourier transform of the frequency domain equalization coefficients to the time domain to obtain the tap coefficients of channel equalization;

[0018] A channel equalization operation is performed based on the tap coefficients.

[0019] In some embodiments of the present application, based on the above solution, the diversity combining process includes:

[0020] De-linear frequency modulation is performed on the signal after channel equalization processing to obtain a first half time diversity signal and a second half time diversity signal; wherein the first half time diversity signal and the second half time diversity signal are both divided into a first half frequency diversity signal and a second half frequency diversity signal;

[0021] Frequency superposition of the first half frequency diversity signal and the second half frequency diversity signal in the first half time diversity signal, and frequency superposition of the first half frequency diversity signal and the second half frequency diversity signal in the second half time diversity signal;

[0022] The first half time diversity signal and the second half time diversity signal after frequency superposition are time superimposed.

[0023] In some embodiments of the present application, based on the foregoing solution, generating a response signal based on the response information includes:

[0024] The response end sequentially performs encoding and spread spectrum processing, MSK modulation processing, frequency diversity processing, up-conversion processing and time diversity processing on the response information to obtain the response signal.

[0025] In some embodiments of the present application, based on the foregoing solution, obtaining the response information based on the received signal includes:

[0026] The interrogation end performs signal separation processing on the received signal by using Fourier transform to obtain the response signal and the target echo signal;

[0027] The response signal is subjected to down-conversion processing, channel equalization processing, diversity combining processing, demodulation and despreading processing, and decoding processing to obtain the response information.

[0028] According to a second aspect of an embodiment of the present application, a beyond-visual-range target recognition device is provided, comprising:

[0029] A first generating unit, configured to generate an inquiry signal based on inquiry information transmitted from the outside, and transmit the inquiry signal to a tropospheric scatter channel;

[0030] a second generating unit, configured to receive the interrogation signal from a tropospheric scatter channel, and obtain the interrogation information based on the interrogation signal;

[0031] a third generating unit, configured to generate response information based on the query information, generate a response signal based on the response information, and transmit the response signal to the tropospheric scatter channel;

[0032] The fourth generating unit is configured to receive a signal transmitted from the tropospheric scatter channel, and obtain the response information based on the received signal.

[0033] According to a third aspect of an embodiment of the present application, a computer-readable storage medium is provided, characterized in that computer instructions are stored in the storage medium, and when the computer instructions are executed on a computer, the computer executes the method according to the first aspect.

[0034] According to a fourth aspect of the embodiments of the present application, there is provided an electronic device, including: a memory and a processor;

[0035] The memory is used to store computer instructions;

[0036] The processor is used to call the computer instructions stored in the memory so that the electronic device executes the method as described in the first aspect.

[0037] The technical solution of the present application can realize beyond-visual-range target recognition, with efficient recognition process and accurate recognition results.

[0038] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0040] Figure 1 A schematic diagram of a process of a beyond-visual-range target recognition method according to an embodiment of the present application is shown;

[0041] Figure 2 A schematic diagram of a process of implementing a method for over-the-horizon target recognition on a radar system according to an embodiment of the present application is shown;

[0042] Figure 3 A schematic diagram of a LFM-MSK signal generation process according to an embodiment of the present application is shown;

[0043] Figure 4 A schematic diagram of a target echo and a response signal separation process according to an embodiment of the present application is shown;

[0044] Figure 5 A block diagram of a beyond-visual-range target recognition device according to an embodiment of the present application is shown;

[0045] Figure 6 A block diagram of an electronic device according to an embodiment of the present application is shown;

[0046] Figure 7 A schematic diagram of the structure of a computer system suitable for implementing an electronic device of an embodiment of the present application is shown. DETAILED DESCRIPTION

[0047] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0048] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0049] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0050] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0051] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the objects used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those shown or described.

[0052] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] Some embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0054] See also Figure 1 , shows a flow chart of a beyond-visual-range target recognition method according to an embodiment of the present application.

[0055] like Figure 1As shown, a method for over-the-horizon target recognition is demonstrated. The method is applied to the interrogation end and the response end of the radar system, and specifically includes steps S100 to S400.

[0056] refer to Figure 1 , step S100, the interrogation end generates an interrogation signal based on the interrogation information transmitted from the outside, and transmits the interrogation signal to the tropospheric scatter channel.

[0057] In some feasible embodiments, based on the above solution, the query end generates an inquiry signal based on the inquiry information transmitted from the outside, including:

[0058] The inquiry end first performs encoding, spread spectrum and MSK modulation processing on the inquiry information; then replicates the processed signal and successively combines it with the LFM signal to obtain a composite signal; finally, time diversity is performed on the composite signal to obtain the inquiry signal.

[0059] For example, see Figure 2 , shows a flow chart of a method for over-the-horizon target recognition implemented on a radar system according to an embodiment of the present application.

[0060] like Figure 2 As shown, the specific process of step S100 is as follows:

[0061] The interrogation end performs information and channel coding on the input interrogation information, and then uses (16,4) Walsh coding for soft spread spectrum, and then performs MSK modulation. The processed signal is replicated and then compounded with the LFM signal. Because the frequency of the LFM signal changes with time, the frequencies of the two LFM-MSK signals are different, achieving frequency diversity. The compounded signal is radiated toward the target multiple times at a certain time interval to achieve time diversity. The radar system adopts time and frequency diversity technology, using the difference in the fading characteristics of the channel for signals of different time and frequency to overcome the influence of fast fading of the tropospheric scattering channel and improve the system signal-to-noise ratio.

[0062] The block diagram of LFM-MSK signal generation is as follows Figure 3 The input sequence is converted into serial and parallel and sent to the I and Q paths respectively and multiplied by the MSK baseband waveform. , Then multiply by the carrier , , and add pilots for channel estimation to complete LFM-MSK modulation. and Represent the carrier frequency and LFM frequency modulation slope respectively. The bit information of a symbol is , using MSK modulation with precoding, The precoded LFM-MSK waveform within a symbol is expressed as:

[0063] ;

[0064] in, is the single symbol time width, For the The initial phase of the code element.

[0065] Continue to refer Figure 1 , step S200, the responding end receives the inquiry signal from the tropospheric scatter channel, and obtains the inquiry information based on the inquiry signal.

[0066] In some feasible embodiments, based on the above solution, obtaining the inquiry information based on the inquiry signal includes:

[0067] The responding end performs down-conversion processing, channel equalization processing, diversity combining processing, demodulation and despreading processing, and decoding processing on the received inquiry signal to obtain the inquiry information.

[0068] It should be noted that the tropospheric scatter channel is a diffuse fading channel, and the signal passing through the tropospheric scatter channel has severe fading. In order to ensure the accuracy of the subsequent signal demodulation and decoding, in step S200, the influence of the diffuse fading channel is suppressed by performing channel equalization and diversity combining processing on the signal.

[0069] In some feasible embodiments, based on the above solution, the channel equalization processing includes:

[0070] The MMSE principle is used to equalize the channel and obtain the frequency domain equalization coefficient of the MMSE equalization algorithm;

[0071] Perform inverse Fourier transform of the frequency domain equalization coefficients to the time domain to obtain the tap coefficients of channel equalization;

[0072] A channel equalization operation is performed based on the tap coefficients.

[0073] In some feasible embodiments, based on the above solution, the diversity combining process includes:

[0074] De-linear frequency modulation is performed on the signal after channel equalization processing to obtain a first half time diversity signal and a second half time diversity signal; wherein the first half time diversity signal and the second half time diversity signal are both divided into a first half frequency diversity signal and a second half frequency diversity signal;

[0075] Frequency superposition of the first half frequency diversity signal and the second half frequency diversity signal in the first half time diversity signal, and frequency superposition of the first half frequency diversity signal and the second half frequency diversity signal in the second half time diversity signal;

[0076] The first half time diversity signal and the second half time diversity signal after frequency superposition are time superimposed.

[0077] Continue to refer Figure 1 , step S300, the responding end generates response information based on the inquiry information, generates a response signal based on the response information, and transmits the response signal to the tropospheric scatter channel.

[0078] In some feasible embodiments, based on the above solution, generating a response signal based on the response information includes:

[0079] The response end sequentially performs encoding and spread spectrum processing, MSK modulation processing, frequency diversity processing, up-conversion processing and time diversity processing on the response information to obtain the response signal.

[0080] like Figure 2 As shown, based on the above example, the specific process of step S200 to step S300 is as follows:

[0081] Transmitting signal After passing through the tropospheric scatter channel, the received signal can be obtained:

[0082] ;

[0083] in, To receive the signal, represents the channel impulse response.

[0084] For receiving signal Down-converting yields:

[0085] ;

[0086] Intercept the time period corresponding to the pilot sequence in the received signal, and use the LS or MMSE algorithm to estimate the channel, and the channel estimation result is obtained as follows: The MMSE principle is used to equalize the channel, and the frequency domain equalization coefficient of the MMSE equalization algorithm is obtained:

[0087] ;

[0088] in represents the conjugate operation, represents the frequency domain channel estimation result, represents the noise power, Indicates the transmitted signal power. Perform inverse Fourier transform to the time domain to obtain the tap coefficients for channel equalization c , thus performing channel equalization operation:

[0089] ;

[0090] Get the baseband LFM-MSK information.

[0091] In the diversity combining process, it is necessary to filter out the linear frequency modulation term in the baseband signal , where a smaller up-conversion is performed on the signal after channel equalization, and the frequency is , and then use the local reference signal and Just mix the low pass. The signal format is:

[0092] ;

[0093] in, , ,and and Just for The even sequence and odd sequence obtained by splitting, at this time and The time slot width .

[0094] I local carrier , after mixing with the received signal and passing through a low-pass filter, the baseband information can be obtained:

[0095] ;

[0096] The local carrier of Q channel is , after mixing and low-pass filtering, we get the baseband information:

[0097] ;

[0098] Perform complex superposition to obtain the de-sloped baseband data:

[0099] ;

[0100] in, Represents the imaginary part of the signal.

[0101] Since the transmitter uses diversity technology, the data of multiple pulses can be combined with equal gain after equalization. The above operation has de-linear frequency modulation of the received signal to obtain two frequency diversity signals under each time diversity. The first half and the second half of the signal are superimposed to complete the equal gain combination of frequency diversity, and then the two processed time diversity signals are superimposed to complete the equal gain combination of time diversity.

[0102] The continuous 16-bit symbol sequence of the received signal after scoring and combining is . Combine it with any set of reference signals (the symbol sequence is ) to perform cross-correlation operation, the reference signal is expressed as: , the result is:

[0103] ;

[0104] The high-frequency component is approximately zero when integrated within a symbol, so it is ignored in the above calculation.

[0105] like and Consistent, due to the use of pre-coded MSK modulation, then and They are and repeat once for each value, then ; According to the above formula After sampling, the final result is 8. and Inconsistency means two different Walsh spreading codes. According to the orthogonality of Walsh codes, the final result of the above formula is 0, which means orthogonality is achieved. The above analysis shows that the signals of two sets of orthogonal Walsh code symbols after pre-coded LFM-MSK modulation are still orthogonal. In this way, joint MSK-Walsh demodulation and de-spreading operations can be realized.

[0106] After the above demodulation and despreading operations, channel decoding and information decoding are performed to obtain the inquiry information. The answering end generates the answer information according to the inquiry information and repeats step S100 to complete the transmission of the answer signal. Unlike the inquiry signal, the answer signal is an MSK signal, which is modulated on two non-overlapping frequencies and does not overlap with the inquiry signal frequency. After the signal is up-converted, it is radiated into the air multiple times at a certain time interval to complete time diversity. The code element can be represented as:

[0107] ;

[0108] in, , ( < ) respectively represent the carrier frequencies of the second diversity of the response signal frequency.

[0109] Continue to refer Figure 1 , step S400, the inquiry end receives the signal transmitted from the tropospheric scatter channel, and obtains the response information based on the received signal.

[0110] In some feasible embodiments, based on the above solution, obtaining the response information based on the received signal includes:

[0111] The interrogation end performs signal separation processing on the received signal by using Fourier transform to obtain the response signal and the target echo signal;

[0112] The response signal is subjected to down-conversion processing, channel equalization processing, diversity combining processing, demodulation and despreading processing, and decoding processing to obtain the response information.

[0113] It should be noted that the signal received by the interrogation end may be a mixed signal formed by the target echo and the response signal, so the mixed signal needs to be separated and processed to separate the target echo and the response signal.

[0114] like Figure 2 As shown, based on the above example, the specific process of step S400 is as follows:

[0115] Will receive signal Perform Fourier transform (FFT) to separate the target echo and the response signal in the frequency domain, and then perform inverse Fourier transform (IFFT) on the separated signals to reconstruct the time domain signals of the target echo and the response signal. For the specific process, see Figure 4 Specifically, to remove the influence of the target echo, we can frame the frequency band where the response signal exists and set other frequency bands to zero, so that only the response signal is retained, and the frequency domain result is IFFT to obtain the reconstructed response signal. Similarly, in the frequency domain, the frequency band outside the target echo is set to zero and IFFT is performed to obtain the time domain reconstruction result of the target echo. Pulse compression and OS-CFAR detection are performed on the reconstructed target echo time domain signal to complete target detection.

[0116] The reconstructed response signal is Perform down-conversion processing and channel equalization, and then use a bandpass filter to separate the two signals. Down-convert the higher frequency signal to zero intermediate frequency, then add the two signals to complete the equal gain merging of frequency diversity, and then add the two signals with a certain time interval to complete the equal gain merging of time diversity to obtain the baseband signal. Perform joint Walsh-MSK demodulation and despreading, channel decoding and information decoding on the combined baseband signal to obtain the response information. The channel equalization and joint Walsh-MSK demodulation and despreading of the inquiry end are exactly the same as those of the response end, which will not be repeated here. See the example of step S200 for details.

[0117] In summary, the technical solution provided by this application has the following characteristics compared with the existing target recognition solution based on secondary radar:

[0118] (1) The existing secondary radar-based target recognition method can only identify targets within the line of sight. For platforms such as ships, due to the limitation of the earth's curvature, the recognition distance of sea surface and low-altitude targets is limited. The present invention expands the target recognition distance of the platform.

[0119] (2) In view of the large signal attenuation and fading faced by tropospheric scatter signal transmission, this method comprehensively adopts channel coding, channel equalization, time and frequency diversity and other technologies to enhance the transmission performance of the identification signal.

[0120] The following describes an embodiment of the device of the present application, which can be used to execute a method for over-the-horizon target recognition in the above embodiment of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the embodiment of the above method of the present application.

[0121] Reference Figure 5 As shown, according to an embodiment of the present application, a beyond-visual-range target recognition device 500 includes:

[0122] A first generating unit 501 is configured to generate an inquiry signal based on inquiry information transmitted from the outside, and transmit the inquiry signal to a tropospheric scatter channel;

[0123] A second generating unit 502 is configured to receive the interrogation signal from a tropospheric scatter channel and obtain the interrogation information based on the interrogation signal;

[0124] A third generating unit 503 is configured to generate response information based on the query information, generate a response signal based on the response information, and transmit the response signal to the tropospheric scatter channel;

[0125] The fourth generating unit 504 is configured to receive a signal transmitted from the tropospheric scatter channel, and obtain the response information based on the received signal.

[0126] like Figure 6As shown, an embodiment of the present application also provides an electronic device 600, including a memory 610, a processor 620, and a computer program 611 stored in the memory 610 and executable on the processor. When the processor 620 executes the computer program 611, the above-mentioned steps of over-the-horizon target recognition based on tropospheric scatter are implemented.

[0127] Since the electronic device introduced in this embodiment is a device used to implement a beyond-visual-range target recognition device in the embodiment of the present application, based on the method introduced in the embodiment of the present application, technical personnel in this field can understand the specific implementation mode of the electronic device of this embodiment and its various variations. Therefore, how the electronic device implements the method in the embodiment of the present application is not introduced in detail here. As long as the equipment used by technical personnel in this field to implement the method in the embodiment of the present application is within the scope of protection of this application.

[0128] During the specific implementation process, when the computer program 611 is executed by a processor, any implementation method in the embodiments corresponding to the first aspect can be implemented.

[0129] Figure 7 A schematic diagram of the structure of a computer system suitable for implementing an electronic device of an embodiment of the present application is shown.

[0130] It should be noted that Figure 7 The computer system 700 of the electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0131] like Figure 7 As shown, the computer system 700 includes a central processing unit (CPU) 701, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 702 or the program loaded from the storage part 708 to the random access memory (RAM) 703, such as executing the method described in the above embodiment. Various programs and data required for system operation are also stored in the random access memory 703. The central processing unit 701, the read-only memory 702 and the random access memory 703 are connected to each other through a bus 704. The input / output (I / O) interface 705 is also connected to the bus 704.

[0132] The following components are connected to the input / output interface 705: an input section 706 including a keyboard, a mouse, etc.; an output section 707 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker; a storage section 708 including a hard disk, etc.; and a communication section 709 including a network interface card such as a LAN (Local Area Network) card, a modem, etc. The communication section 709 performs communication processing via a network such as the Internet. A drive 710 is also connected to the input / output interface 705 as needed. A removable medium 711, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 710 as needed so that a computer program read therefrom is installed into the storage section 708 as needed.

[0133] In particular, according to an embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through the communication part 709, and / or installed from a removable medium 711. When the computer program is executed by the central processing unit (CPU) 701, various functions defined in the system of the present application are executed.

[0134] It should be noted that the computer-readable medium shown in the embodiment of the present application may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, device or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, which may send, propagate, or transmit programs for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0135] The flowchart and block diagram in the accompanying drawings illustrate the possible architecture, functions and operations of the system, method and computer program product according to various embodiments of the present application. Wherein, each box in the flowchart or block diagram can represent a module, a program segment, or a part of the code, and the above-mentioned module, program segment, or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0136] The units involved in the embodiments described in this application may be implemented by software or hardware, and the units described may also be set in a processor. The names of these units do not, in some cases, constitute limitations on the units themselves.

[0137] As another aspect, the present application further provides a computer program product or a computer program, the computer program product or the computer program including computer instructions, the computer instructions being stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes a method for over-the-horizon target recognition described in the above embodiment.

[0138] As another aspect, the present application also provides a computer-readable medium, which may be included in the electronic device described in the above embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by an electronic device, the electronic device implements a beyond-visual-range target recognition method described in the above embodiment.

[0139] It should be noted that, although several modules or units of the equipment for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiments of the present application, the features and functions of two or more modules or units described above can be embodied in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into being embodied by multiple modules or units.

[0140] Through the description of the above implementation methods, it is easy for those skilled in the art to understand that the example implementation methods described here can be implemented by software, or by combining software with necessary hardware. Therefore, the technical solution according to the implementation method of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the implementation method of the present application.

[0141] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in the present application. It should be understood that the present application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for over-the-horizon target recognition, applied to the interrogation end and the response end of a radar system, characterized in that: include: The interrogation end generates an interrogation signal based on interrogation information transmitted from the outside, and transmits the interrogation signal to a tropospheric scatter channel; The responding end receives the inquiry signal from the tropospheric scatter channel, and obtains the inquiry information based on the inquiry signal; The responding end generates response information based on the inquiry information, generates a response signal based on the response information, and transmits the response signal to the tropospheric scatter channel; The interrogation end receives the signal transmitted from the tropospheric scatter channel, and obtains the response information based on the received signal; The query end generates a query signal based on the query information transmitted from the outside, including: The inquiry end first performs encoding, spectrum spreading and MSK modulation processing on the inquiry information; then replicates the processed signal and successively combines it with the LFM signal to obtain a composite signal; finally, performs time diversity on the composite signal to obtain the inquiry signal; The obtaining the inquiry information based on the inquiry signal comprises: The responding end performs down-conversion processing, channel equalization processing, diversity combining processing, demodulation and despreading processing, and decoding processing on the received inquiry signal to obtain the inquiry information.

2. The method according to claim 1, characterized in that The channel equalization processing comprises: The MMSE principle is used to equalize the channel and obtain the frequency domain equalization coefficient of the MMSE equalization algorithm; Perform inverse Fourier transform of the frequency domain equalization coefficients to the time domain to obtain the tap coefficients of channel equalization; A channel equalization operation is performed based on the tap coefficients.

3. The method according to claim 2, characterized in that The diversity combining process comprises: De-linear frequency modulation is performed on the signal after channel equalization processing to obtain a first half time diversity signal and a second half time diversity signal; wherein the first half time diversity signal and the second half time diversity signal are both divided into a first half frequency diversity signal and a second half frequency diversity signal; Frequency superposition of the first half frequency diversity signal and the second half frequency diversity signal in the first half time diversity signal, and frequency superposition of the first half frequency diversity signal and the second half frequency diversity signal in the second half time diversity signal; The first half time diversity signal and the second half time diversity signal after frequency superposition are time superimposed.

4. The method according to claim 1, characterized in that: The generating a response signal based on the response information comprises: The response end sequentially performs encoding and spread spectrum processing, MSK modulation processing, frequency diversity processing, up-conversion processing and time diversity processing on the response information to obtain the response signal.

5. The method according to claim 1, characterized in that The obtaining the response information based on the received signal comprises: The interrogation end performs signal separation processing on the received signal by using Fourier transform to obtain the response signal and the target echo signal; The response signal is subjected to down-conversion processing, channel equalization processing, diversity combining processing, demodulation and despreading processing, and decoding processing to obtain the response information.

6. A beyond-visual-range target recognition device, characterized in that: include: A first generating unit, configured to generate an inquiry signal based on inquiry information transmitted from the outside, and transmit the inquiry signal to a tropospheric scatter channel; The step of generating an inquiry signal based on inquiry information transmitted from the outside world includes: First, the inquiry information is coded, spread-spectrum processed, and MSK modulated; then, the processed signal is copied and successively composited with the LFM signal to obtain a composite signal; finally, the composite signal is time-diversified to obtain the inquiry signal; A second generating unit, configured to receive the interrogation signal from a tropospheric scatter channel, and obtain the interrogation information based on the interrogation signal; Wherein, obtaining the inquiry information based on the inquiry signal includes: The inquiry information is obtained by performing down-conversion processing, channel equalization processing, diversity combining processing, demodulation and despreading processing, and decoding processing on the received inquiry signal; a third generating unit, configured to generate response information based on the query information, generate a response signal based on the response information, and transmit the response signal to the tropospheric scatter channel; The fourth generating unit is configured to receive a signal transmitted from the tropospheric scatter channel, and obtain the response information based on the received signal.

7. A computer-readable storage medium, characterized in that: The storage medium stores computer instructions, and when the computer instructions are executed on a computer, the computer is enabled to execute the method according to any one of claims 1 to 5.

8. An electronic device, characterized in that: include: Memory and processor; The memory is used to store computer instructions; The processor is used to call the computer instructions stored in the memory so that the electronic device executes the method as described in any one of claims 1-5.

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