A method, device, equipment and medium for extracting electromagnetic characteristics of a moving target

Abstract

The present invention relates to a method, device, equipment and medium for extracting electromagnetic characteristics of a moving target. Method: Based on the motion parameters of the moving target, a simulation calculation is performed on it to obtain a plasma flow field covering the target; different regions in the plasma flow field have different second radial velocities relative to the radar, and the motion parameters include the first radial velocity of the target relative to the radar, and the first radial velocity is different from the second radial velocity; based on the moving target and the plasma flow field, a simplified equivalent model is constructed; the simplified equivalent model includes a first scattering point and multiple second scattering points, the first scattering point represents the moving target, and different second scattering points represent different regions in the plasma flow field; in response to using a radar to send an electromagnetic wave to the simplified equivalent model, a final echo signal of the simplified equivalent model is obtained; the final echo signal is feature extracted to obtain the electromagnetic characteristics of the moving target. The method can accurately extract the electromagnetic characteristics of the moving target.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of radar technology, and in particular to a method, device, equipment and medium for extracting electromagnetic characteristics of a moving target. Background Art

[0002] When a moving target flies at high speed, it will have intense friction with the surrounding atmosphere, causing the air to ionize and produce plasma, forming a plasma flow field surrounding the moving target. The plasma flow field will interact with the incident electromagnetic waves, thereby changing the electromagnetic characteristics of the moving target, which brings great difficulties to radar detection, tracking and identification of high-speed moving targets. Therefore, in order to eliminate the influence of the plasma flow field on the electromagnetic characteristics of the moving target, it is necessary to perform velocity compensation on the echo signals of the moving target and the plasma flow field surrounding the moving target to obtain the compensated echo signal, and then extract the electromagnetic characteristics of the target from the compensated echo signal.

[0003] In the related art, when performing velocity compensation on the echo signals of the moving target and the plasma flow field, the moving target and the plasma flow field are usually taken as a whole, and the compensation velocity uses the estimated velocity of the moving target. However, there is a large difference between the estimated velocity of the moving target and the velocity distribution of the plasma flow field, resulting in inaccurate velocity compensation of the plasma flow field, and thus the echo signals of the moving target and the plasma flow field cannot be accurately obtained, resulting in inaccurate electromagnetic characteristics of the moving target extracted from the echo signals.

[0004] Based on this, there is an urgent need for a method, device, equipment and medium for extracting electromagnetic characteristics of moving targets to solve the above technical problems. Summary of the invention

[0005] The embodiments of the present invention provide a method, device, equipment and medium for extracting electromagnetic characteristics of a moving target, which can accurately extract the electromagnetic characteristics of the moving target.

[0006] In a first aspect, an embodiment of the present invention provides a method for extracting electromagnetic features of a moving target, comprising:

[0007] Based on the motion parameters of the moving target, a simulation calculation is performed on the moving target to obtain a plasma flow field covering the moving target; wherein different regions within the plasma flow field have different second radial velocities relative to the radar, and the motion parameters include a first radial velocity of the moving target relative to the radar, and the first radial velocity is different from the second radial velocity;

[0008] Based on the moving target and the plasma flow field, a simplified equivalent model is constructed; wherein the simplified equivalent model includes a first scattering point and a plurality of second scattering points, the first scattering point represents the moving target, and different second scattering points represent different regions in the plasma flow field;

[0009] In response to using the radar to send electromagnetic waves to the simplified equivalent model, a final echo signal of the simplified equivalent model is obtained;

[0010] Feature extraction is performed on the final echo signal to obtain the electromagnetic features of the moving target.

[0011] In a possible design, in response to using the radar to send electromagnetic waves to the simplified equivalent model, obtaining a final echo signal of the simplified equivalent model includes:

[0012] In response to using the radar to send electromagnetic waves to the simplified equivalent model, a first echo signal returned by the first scattering point and a second echo signal returned by the second scattering point are obtained;

[0013] performing velocity compensation on the first echo signal using the first radial velocity to obtain a third echo signal;

[0014] For each of the second scattering points, using the second radial velocity of the current second scattering point, velocity compensation is performed on the second echo signal returned by the current second scattering point to obtain a fourth echo signal;

[0015] The obtained third echo signal and all fourth echo signals are vector-added to obtain a final echo signal of the simplified equivalent model.

[0016] In a possible design, the electromagnetic wave is a linear frequency modulation wave LFM; the signal expression of the linear frequency modulation wave LFM is:

[0017]

[0018] Where, T P is the pulse width; k is the slope of the linear frequency modulation signal, B is the signal bandwidth; f c is the signal carrier frequency, For the fast time of the linear frequency modulation wave LFM, the range is

[0019] In a possible design, expressions of a first echo signal returned by the first scattering point and a second echo signal returned by each of the second scattering points are:

[0020]

[0021] Where R is the distance from the scattering point to the radar, V is the radial velocity of the scattering point relative to the radar, R 0 is the initial distance from the scattering point to the radar, c is the speed of light, and A is the amplitude of the scattering point.

[0022] In one possible design, the phase error caused by the radial velocity of each scattering point is:

[0023]

[0024] The using the first radial velocity to perform velocity compensation on the first echo signal to obtain a third echo signal includes:

[0025] Use e -j2π(-Δψ(t)) Performing velocity compensation on the first echo signal to obtain a third echo signal;

[0026] The method of performing velocity compensation on the second echo signal returned by the current second scattering point by using the second radial velocity of the current second scattering point for each of the second scattering points to obtain a fourth echo signal includes:

[0027] Use e -j2π(-Δψ(t)) Performing velocity compensation on each of the second echo signals to obtain a fourth echo signal;

[0028] The expressions of the third echo signal and the fourth echo signal are:

[0029]

[0030] In a possible design, the electromagnetic characteristics of the moving target include spectrum characteristics and a one-dimensional range image;

[0031] The step of extracting features from the final echo signal to obtain electromagnetic features of the moving target includes:

[0032] Performing short-time Fourier transform on the final echo signal to obtain the frequency spectrum characteristics of the moving target;

[0033] The final echo signal is mixed and de-tilted to obtain a third echo signal; the third echo signal is inversely Fourier transformed to obtain a one-dimensional range image of the moving target.

[0034] In a second aspect, an embodiment of the present invention further provides a device for extracting electromagnetic characteristics of a moving target, comprising:

[0035] A calculation module, configured to perform simulation calculation on the moving target based on the moving parameters of the moving target, and obtain a plasma flow field covering the moving target; wherein different regions within the plasma flow field have different second radial velocities relative to the radar, and the moving parameters include a first radial velocity of the moving target relative to the radar, and the first radial velocity is different from the second radial velocity;

[0036] A construction module, used to construct a simplified equivalent model based on the moving target and the plasma flow field; wherein the simplified equivalent model includes a first scattering point and a plurality of second scattering points, the first scattering point represents the moving target, and different second scattering points represent different regions in the plasma flow field;

[0037] an acquisition module, configured to obtain a final echo signal of the simplified equivalent model in response to sending an electromagnetic wave to the simplified equivalent model using the radar;

[0038] The extraction module is used to extract features from the final echo signal to obtain the electromagnetic features of the moving target.

[0039] In one possible design, the obtaining module is used to perform the following operations:

[0040] In response to using the radar to send electromagnetic waves to the simplified equivalent model, a first echo signal returned by the first scattering point and a second echo signal returned by the second scattering point are obtained;

[0041] performing velocity compensation on the first echo signal using the first radial velocity to obtain a third echo signal;

[0042] For each of the second scattering points, using the second radial velocity of the current second scattering point, velocity compensation is performed on the second echo signal returned by the current second scattering point to obtain a fourth echo signal;

[0043] The obtained third echo signal and all fourth echo signals are vector-added to obtain a final echo signal of the simplified equivalent model.

[0044] In a third aspect, an embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method described in any embodiment of this specification is implemented.

[0045] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, enables the computer to execute the method described in any embodiment of this specification.

[0046] The embodiment of the present invention provides a method, device, equipment and medium for extracting electromagnetic characteristics of a moving target. The method first performs simulation calculation based on the motion parameters of the moving target to obtain a plasma flow field covering the moving target, wherein the plasma flow field has multiple regions, and the physical parameter distribution of different regions and the second radial velocity of different regions relative to the radar are different, and the first radial velocity of the moving target relative to the radar is different from the second radial velocity; then, based on the difference between the moving target and the different regions of the plasma flow field, a simplified equivalent model of the moving target and the plasma flow field is constructed, the moving target is equivalent to a first scattering point, and different regions in the plasma flow field are equivalent to independent second scattering points respectively; then, in response to using a radar to send an electromagnetic wave to the simplified equivalent model, that is, to send an electromagnetic wave to each scattering point, a final echo signal of the simplified equivalent model is obtained, that is, an echo signal composed of the echo signals of all the scattering points. Since the echo signal corresponding to each scattering point is more accurate, the echo signal composed of the combination is more accurate, and the echo signal is used to extract features, so that the electromagnetic characteristics of the moving target are more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 It is a structural schematic diagram of a method for extracting electromagnetic characteristics of a moving target provided by an embodiment of the present invention;

[0049] Figure 2 is a simplified equivalent model schematic diagram provided by an embodiment of the present invention;

[0050] Figure 3 yes Figure 2 Schematic diagram of the simplified equivalent model shown relative to the radar observation direction;

[0051] Figure 4 It is a time domain spectrum extracted without using the method of the present application provided by an embodiment of the present invention;

[0052] Figure 5 is a one-dimensional range image provided by an embodiment of the present invention that is not extracted using the method of the present application;

[0053] Figure 6 It is a one-dimensional range image extracted by the method of the present application provided by an embodiment of the present invention;

[0054] Figure 7is a hardware architecture diagram of an electronic device provided by an embodiment of the present invention;

[0055] Figure 8 It is a structural diagram of a device for extracting electromagnetic characteristics of a moving target provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0057] As mentioned above, the relevant technology cannot accurately extract the electromagnetic characteristics of the moving target from the echo signal of the moving target and the plasma flow field.

[0058] In response to this problem, the inventors found that this is because the existing methods usually assume that the plasma flow field and the moving target are relatively stationary, but in fact the speed difference between the two is large, and the plasma flow field itself also has the characteristics of uneven distribution. Therefore, if the target's movement speed is used to compensate the echo signal, the speed compensation of the plasma flow field will be inaccurate, and an accurate echo signal cannot be obtained, which in turn affects the accuracy of the extracted target electromagnetic characteristics, causing spectrum broadening and one-dimensional range image defocusing in the radar measurement process, which seriously affects the detection and tracking of the radar.

[0059] Based on this, the inventors proposed to calculate the echo signals of the moving target and the plasma flow field separately, so as to obtain a more accurate echo signal and then extract accurate target features.

[0060] The specific implementation of the above concept is described below.

[0061] Please refer to Figure 1 The embodiment of the present invention provides a method for extracting electromagnetic characteristics of a moving target, the method comprising:

[0062] Step 100, based on the motion parameters of the moving target, a simulation calculation is performed on the moving target to obtain a plasma flow field covering the moving target; wherein different regions in the plasma flow field have different second radial velocities relative to the radar, and the motion parameters include a first radial velocity of the moving target relative to the radar, and the first radial velocity is different from the second radial velocity;

[0063] Step 102, constructing a simplified equivalent model based on the moving target and the plasma flow field; wherein the simplified equivalent model includes a first scattering point and a plurality of second scattering points, the first scattering point represents the moving target, and different second scattering points represent different regions in the plasma flow field;

[0064] Step 104, in response to using a radar to send an electromagnetic wave to the simplified equivalent model, a final echo signal of the simplified equivalent model is obtained;

[0065] Step 106: extract features from the final echo signal to obtain electromagnetic features of the moving target.

[0066] In an embodiment of the present invention, firstly, a simulation calculation is performed based on the motion parameters of a moving target to obtain a plasma flow field covering the moving target, wherein the plasma flow field has multiple regions, and the physical parameter distributions of different regions and the second radial velocities of different regions relative to a radar are different, and the first radial velocity of the moving target relative to the radar is different from the second radial velocity; then, based on the difference between the moving target and different regions of the plasma flow field, a simplified equivalent model of the moving target and the plasma flow field is constructed, the moving target is equivalent to a first scattering point, and different regions in the plasma flow field are equivalent to independent second scattering points respectively; then, in response to using a radar to send an electromagnetic wave to the simplified equivalent model, that is, to send an electromagnetic wave to each scattering point, a final echo signal of the simplified equivalent model is obtained, that is, an echo signal formed by combining the echo signals of all scattering points, and since the echo signal corresponding to each scattering point is more accurate, the echo signal formed by the combination thereof is more accurate, and feature extraction is performed using the echo signal, so that the electromagnetic features of the moving target obtained are more accurate.

[0067] Described below Figure 1 How the various steps are performed.

[0068] First, for step 100, based on the motion parameters of the moving target, the moving target is simulated and calculated to obtain a plasma flow field covering the moving target; wherein different areas within the plasma flow field have different second radial velocities relative to the radar, and the motion parameters include a first radial velocity of the moving target relative to the radar, and the first radial velocity is different from the second radial velocity.

[0069] In this step, the moving target can be of any shape, such as a sphere, etc. The moving target's motion parameters include the target's flight altitude, flight speed, and angle of attack, etc. With these parameters, the plasma flow field generated by the target's motion and the distribution of physical parameters of the plasma flow field can be accurately simulated. The physical parameters include the velocity, electron density, temperature, and pressure in different regions of the flow field. The plasma flow field can be divided into multiple regions according to the distribution of physical parameters, and the physical parameter distribution of each region is different, and each region has a different second radial velocity relative to the radar. Due to the above differences, the electromagnetic characteristics of each region in the plasma flow field are different. Therefore, it is necessary to analyze the electromagnetic characteristics of each region separately.

[0070] Then, for step 102, a simplified equivalent model is constructed based on the moving target and the plasma flow field; wherein the simplified equivalent model includes a first scattering point and multiple second scattering points, the first scattering point represents the moving target, and different second scattering points represent different areas in the plasma flow field.

[0071] In this step, the construction of a simplified equivalent model is based on the difference between the electromagnetic characteristics of the moving target and the electromagnetic characteristics of different regions of the plasma flow field. According to the difference in electromagnetic characteristics, the moving target and different regions of the plasma flow field are equivalent to the first scattering point and the second scattering point, respectively, to facilitate the calculation of each scattering point separately and obtain a more accurate echo signal.

[0072] Then, with respect to step 104 , in response to using the radar to send electromagnetic waves to the simplified equivalent model, a final echo signal of the simplified equivalent model is obtained.

[0073] In some embodiments, the specific process of this step includes:

[0074] Step A1, in response to sending electromagnetic waves to the simplified equivalent model using a radar, a first echo signal returned by a first scattering point and a second echo signal returned by a second scattering point are obtained;

[0075] Step A2, performing velocity compensation on the first echo signal using the first radial velocity to obtain a third echo signal;

[0076] Step A3, for each second scattering point, using the second radial velocity of the current second scattering point, velocity compensation is performed on the second echo signal returned by the current second scattering point to obtain a fourth echo signal;

[0077] Step A4: performing vector addition on the obtained third echo signal and all fourth echo signals to obtain a final echo signal of the simplified equivalent model.

[0078] In some embodiments, the electromagnetic wave sent by the radar in step A1 is a frequency modulated wave LFM;

[0079] The signal expression of the linear frequency modulation wave LFM is:

[0080]

[0081] Where, T P is the pulse width; k is the slope of the linear frequency modulation signal, B is the signal bandwidth; f c is the signal carrier frequency, For the fast time of the linear frequency modulation wave LFM, the range is

[0082] After the electromagnetic wave is incident on each scattering point, it is reflected by the scattering point to form a radar echo. The expressions of the first echo signal returned by the first scattering point and the second echo signal returned by each second scattering point are:

[0083]

[0084] Where R is the distance from the scattering point to the radar, V is the radial velocity of the scattering point relative to the radar, R 0 is the initial distance from the scattering point to the radar, c is the speed of light, and A is the amplitude of the scattering point.

[0085] In this step, due to the influence of the radial velocity of the scattering point, the echo signal received by the radar has a phase error. The expression of the phase error is as follows:

[0086]

[0087] Therefore, in steps A2 and A3, it is necessary to perform velocity compensation on the first echo signal and the second echo signal respectively. The specific compensation method is:

[0088] Use e -j2π(-Δψ(t)) Performing velocity compensation on the first echo signal to obtain a third echo signal;

[0089] Use e -j2π(-Δψ(t)) Performing velocity compensation on each second echo signal to obtain a fourth echo signal;

[0090] The expressions of the third echo signal and the fourth echo signal are:

[0091]

[0092] In the above steps, since the radial velocity of each scattering point is used to compensate for the echo signal, the compensated echo signal is more accurate. The final echo signal obtained by vector addition of the compensated echo signals has a higher accuracy.

[0093] Finally, for step 106, feature extraction is performed on the final echo signal to obtain the electromagnetic features of the moving target.

[0094] In this step, the electromagnetic characteristics of the moving target include spectrum characteristics and one-dimensional range image.

[0095] In terms of spectral characteristics, the target echo signals detected by radar are transient and unstable, and contain many instantaneous frequency components. In order to obtain the instantaneous frequency of each component, Gabor, inspired by quantum mechanics, suggested using two-dimensional coordinates of time and frequency to represent the signal. In 1946, he used Gaussian function as the expansion function to decompose the signal and proposed Gabor expansion. He used a very narrow window function to extract the signal and calculated its Fourier transform. This spectrum is called the local spectrum. His work led to the short-time Fourier transform (STFT), which is a two-dimensional representation of the signal in time and frequency. The definition of STFT is:

[0096]

[0097] Where g(t) is a “narrow” window function, * represents the complex conjugate, and s(u) represents the echo signal.

[0098] Based on the above principle, the frequency spectrum characteristics of the moving target can be obtained by performing short-time Fourier transform on the final echo signal;

[0099] For the one-dimensional range image, according to the linear frequency modulation waveform (LFM) theory, after mixing and de-tilting processing, the received echo corresponding to a single transmitted pulse of the LFM radar and the distribution of the target scattering center with radial distance (i.e., the one-dimensional range image) are inverse Fourier transform relations.

[0100] Based on the above principle, the final echo signal is mixed and de-tilted to obtain the third echo signal, and then the third echo signal is inversely Fourier transformed to obtain a one-dimensional range image of the moving target.

[0101] The effect of the present invention is demonstrated by a specific embodiment below:

[0102] like Figure 2As shown in FIG. 1 , it is a simplified schematic diagram of an equivalent model provided in this embodiment. It can be seen from the figure that the moving target is a sphere flying at high speed, and the sphere is surrounded by a plasma flow field. The flow field includes different regions. The moving target and each region are respectively equivalent to different scattering points. The RCS (amplitude) and radial velocity of each scattering point are shown in Table 1:

[0103] Table 1 RCS (amplitude) and radial velocity of each scattering point

[0104]

[0105] like Figure 3 As shown, Figure 2 The simplified equivalent model shown is a schematic diagram relative to the radar observation direction. It can be seen from the figure that the initial distance of each scattering point from the radar observation direction is 800km. When the radar transmits electromagnetic waves to the simplified equivalent model with a center frequency of 5GHz and a bandwidth of 5MHz, if the received echo signal is not compensated for velocity, the extracted time domain spectrum is as follows: Figure 4 As shown, from Figure 4 It can be seen that the radar echo has a wide spectrum, indicating that the radar echo is disturbed by the plasma flow field. Without velocity compensation, the extracted one-dimensional distance image is as follows: Figure 5 As shown, from Figure 5 It can be seen that the one-dimensional range image has serious defocusing phenomenon. After the echo signal is velocity compensated by the method of the present application, the extracted one-dimensional range image is as follows: Figure 6 As shown in the figure, it can be seen that the defocusing phenomenon of the one-dimensional distance image has disappeared.

[0106] It can be seen from this embodiment that the method of the present application can accurately extract the electromagnetic characteristics of a moving target.

[0107] like Figure 7 , Figure 8 As shown, an embodiment of the present invention provides a device for extracting electromagnetic characteristics of a moving target. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, Figure 7 FIG. 1 is a hardware architecture diagram of an electronic device in which a moving target electromagnetic feature extraction device provided by an embodiment of the present invention is located. Figure 7 In addition to the processor, memory, network interface, and non-volatile memory shown, the electronic device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing messages, etc. Taking software implementation as an example, Figure 8 As shown, as a device in a logical sense, the CPU of the electronic device in which it is located reads the corresponding computer program in the non-volatile memory into the internal memory and runs it.

[0108] This embodiment provides a device for extracting electromagnetic characteristics of a moving target, including:

[0109] The calculation module 800 is used to perform simulation calculation on the moving target based on the motion parameters of the moving target to obtain a plasma flow field covering the moving target; wherein different regions in the plasma flow field have different second radial velocities relative to the radar, and the motion parameters include a first radial velocity of the moving target relative to the radar, and the first radial velocity is different from the second radial velocity;

[0110] A construction module 802 is used to construct a simplified equivalent model based on the moving target and the plasma flow field; wherein the simplified equivalent model includes a first scattering point and a plurality of second scattering points, the first scattering point represents the moving target, and different second scattering points represent different regions in the plasma flow field;

[0111] An acquisition module 804 is used to obtain a final echo signal of the simplified equivalent model in response to sending an electromagnetic wave to the simplified equivalent model using a radar;

[0112] The extraction module 806 is used to extract features from the final echo signal to obtain the electromagnetic features of the moving target.

[0113] In an embodiment of the present invention, the calculation module 800 can be used to execute step 102 in the above method embodiment, the construction module 802 can be used to execute step 102 in the above method embodiment, the acquisition module 804 can be used to execute step 104 in the above method embodiment, and the extraction module 806 can be used to execute step 106 in the above method embodiment.

[0114] In some implementations, the obtaining module 804 is used to perform:

[0115] In response to transmitting electromagnetic waves to the simplified equivalent model using a radar, a first echo signal returned by a first scattering point and a second echo signal returned by a second scattering point are obtained;

[0116] Performing velocity compensation on the first echo signal using the first radial velocity to obtain a third echo signal;

[0117] For each second scattering point, using the second radial velocity of the current second scattering point, velocity compensation is performed on the second echo signal returned by the current second scattering point to obtain a fourth echo signal;

[0118] The obtained third echo signal and all fourth echo signals are vector-added to obtain a final echo signal of the simplified equivalent model.

[0119] In some embodiments, the electromagnetic wave is a linear frequency modulation wave LFM; the signal expression of the linear frequency modulation wave LFM is:

[0120]

[0121] Where, T P is the pulse width; k is the slope of the linear frequency modulation signal, B is the signal bandwidth; f c is the signal carrier frequency, For the fast time of the linear frequency modulation wave LFM, the range is

[0122] In some embodiments, the expressions of the first echo signal returned by the first scattering point and the second echo signal returned by each second scattering point are:

[0123]

[0124] Where R is the distance from the scattering point to the radar, V is the radial velocity of the scattering point relative to the radar, R 0 is the initial distance from the scattering point to the radar, c is the speed of light, and A is the amplitude of the scattering point.

[0125] In some embodiments, the phase error caused by the radial velocity of each scattering point is:

[0126]

[0127] Performing velocity compensation on the first echo signal by using the first radial velocity to obtain a third echo signal includes:

[0128] Use e -j2π(-Δψ(t)) Performing velocity compensation on the first echo signal to obtain a third echo signal;

[0129] For each second scattering point, using the second radial velocity of the current second scattering point, velocity compensation is performed on the second echo signal returned by the current second scattering point to obtain a fourth echo signal, including:

[0130] Use e -j2π(-Δψ(t)) Performing velocity compensation on each second echo signal to obtain a fourth echo signal;

[0131] The expressions of the third echo signal and the fourth echo signal are:

[0132]

[0133] In some embodiments, the electromagnetic characteristics of the moving target include spectrum characteristics and a one-dimensional range image; the extraction module 806 is used to perform:

[0134] Perform short-time Fourier transform on the final echo signal to obtain the spectrum characteristics of the moving target;

[0135] The final echo signal is mixed and de-tilted to obtain a third echo signal; the third echo signal is inversely Fourier transformed to obtain a one-dimensional range image of the moving target.

[0136] It is to be understood that the structure illustrated in the embodiment of the present invention does not constitute a specific limitation on a device for extracting electromagnetic characteristics of a moving target. In other embodiments of the present invention, a device for extracting electromagnetic characteristics of a moving target may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0137] The information interaction, execution process and other contents between the modules in the above-mentioned device are based on the same concept as the embodiment of the method of the present invention. For the specific contents, please refer to the description in the embodiment of the method of the present invention, and no further description is given here.

[0138] An embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, a method for extracting electromagnetic characteristics of a moving target in any embodiment of the present invention is implemented.

[0139] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the processor executes a method for extracting electromagnetic features of a moving target in any embodiment of the present invention.

[0140] Specifically, a system or device equipped with a storage medium can be provided, on which software program code that implements the functions of any of the above-mentioned embodiments is stored, and a computer (or CPU or MPU) of the system or device can be enabled to read and execute the program code stored in the storage medium.

[0141] In this case, the program code itself read from the storage medium can realize the function of any one of the above-mentioned embodiments, and thus the program code and the storage medium storing the program code constitute a part of the present invention.

[0142] The storage medium embodiments for providing the program code include a floppy disk, a hard disk, a magneto-optical disk, an optical disk (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), a magnetic tape, a non-volatile memory card, and a ROM. Alternatively, the program code can be downloaded from a server computer by a communication network.

[0143] In addition, it should be clear that the functions of any of the above embodiments can be implemented not only by executing the program code read by the computer, but also by enabling an operating system operating on the computer to complete part or all of the actual operations based on instructions from the program code.

[0144] In addition, it can be understood that the program code read from the storage medium is written to a memory provided in an expansion board inserted into the computer or to a memory provided in an expansion module connected to the computer, and then based on the instructions of the program code, a CPU installed on the expansion board or expansion module is enabled to perform part or all of the actual operations, thereby realizing the functions of any of the above-mentioned embodiments.

[0145] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical factors in the process, method, article or device including the elements.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for extracting electromagnetic characteristics of a moving target, characterized in that: include: Based on the motion parameters of the moving target, a simulation calculation is performed on the moving target to obtain a plasma flow field covering the moving target; wherein different regions within the plasma flow field have different second radial velocities relative to the radar, and the motion parameters include a first radial velocity of the moving target relative to the radar, and the first radial velocity is different from the second radial velocity; Based on the moving target and the plasma flow field, a simplified equivalent model is constructed; wherein the simplified equivalent model includes a first scattering point and a plurality of second scattering points, the first scattering point represents the moving target, and different second scattering points represent different regions in the plasma flow field; In response to using the radar to send electromagnetic waves to the simplified equivalent model, a final echo signal of the simplified equivalent model is obtained; Feature extraction is performed on the final echo signal to obtain the electromagnetic features of the moving target.

2. The method according to claim 1, characterized in that: The step of obtaining a final echo signal of the simplified equivalent model in response to transmitting an electromagnetic wave to the simplified equivalent model using the radar comprises: In response to using the radar to send electromagnetic waves to the simplified equivalent model, a first echo signal returned by the first scattering point and a second echo signal returned by the second scattering point are obtained; performing velocity compensation on the first echo signal using the first radial velocity to obtain a third echo signal; For each of the second scattering points, using the second radial velocity of the current second scattering point, velocity compensation is performed on the second echo signal returned by the current second scattering point to obtain a fourth echo signal; The obtained third echo signal and all fourth echo signals are vector-added to obtain a final echo signal of the simplified equivalent model.

3. The method according to claim 2, characterized in that The electromagnetic wave is a linear frequency modulation wave LFM; the signal expression of the linear frequency modulation wave LFM is: Where, T P is the pulse width; k is the slope of the linear frequency modulation signal, B is the signal bandwidth; f c is the signal carrier frequency, For the fast time of the linear frequency modulation wave LFM, the range is 4. The method according to claim 3, characterized in that The expressions of the first echo signal returned by the first scattering point and the second echo signal returned by each of the second scattering points are: Where R is the distance from the scattering point to the radar, V is the radial velocity of the scattering point relative to the radar, R0 is the initial distance from the scattering point to the radar, c is the speed of light, and A is the amplitude of the scattering point.

5. The method according to claim 4, characterized in that The phase error caused by the radial velocity of each scattering point is: The using the first radial velocity to perform velocity compensation on the first echo signal to obtain a third echo signal includes: Use e -j2π(-Δψ(t)) Performing velocity compensation on the first echo signal to obtain a third echo signal; The method of performing velocity compensation on the second echo signal returned by the current second scattering point by using the second radial velocity of the current second scattering point for each of the second scattering points to obtain a fourth echo signal includes: Use e -j2π(-Δψ(t)) Performing velocity compensation on each of the second echo signals to obtain a fourth echo signal; The expressions of the third echo signal and the fourth echo signal are:

6. The method according to claim 1, characterized in that The electromagnetic characteristics of the moving target include spectrum characteristics and one-dimensional range image; The step of extracting features from the final echo signal to obtain electromagnetic features of the moving target includes: Performing short-time Fourier transform on the final echo signal to obtain the frequency spectrum characteristics of the moving target; The final echo signal is mixed and de-tilted to obtain a third echo signal; the third echo signal is inversely Fourier transformed to obtain a one-dimensional range image of the moving target.

7. A device for extracting electromagnetic characteristics of a moving target, characterized in that: include: A calculation module, configured to perform simulation calculation on the moving target based on the moving parameters of the moving target, and obtain a plasma flow field covering the moving target; wherein different regions within the plasma flow field have different second radial velocities relative to the radar, and the moving parameters include a first radial velocity of the moving target relative to the radar, and the first radial velocity is different from the second radial velocity; A construction module, used to construct a simplified equivalent model based on the moving target and the plasma flow field; wherein the simplified equivalent model includes a first scattering point and a plurality of second scattering points, the first scattering point represents the moving target, and different second scattering points represent different regions in the plasma flow field; an acquisition module, configured to obtain a final echo signal of the simplified equivalent model in response to sending an electromagnetic wave to the simplified equivalent model using the radar; The extraction module is used to extract features from the final echo signal to obtain the electromagnetic features of the moving target.

8. The device according to claim 7, characterized in that The acquisition module is used to perform the following operations: In response to using the radar to send electromagnetic waves to the simplified equivalent model, a first echo signal returned by the first scattering point and a second echo signal returned by the second scattering point are obtained; performing velocity compensation on the first echo signal using the first radial velocity to obtain a third echo signal; For each of the second scattering points, using the second radial velocity of the current second scattering point, velocity compensation is performed on the second echo signal returned by the current second scattering point to obtain a fourth echo signal; The obtained third echo signal and all fourth echo signals are vector-added to obtain a final echo signal of the simplified equivalent model.

9. A computing device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute the method according to any one of claims 1 to 6.

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