Frequency Modulated Continuous Wave (CSAR) Distance Offset Compensation Method and Terminal Equipment

Abstract

The present invention provides a distance offset compensation method and terminal device for frequency modulated continuous wave CSAR. The method comprises: obtaining the system parameters of frequency modulated continuous wave CSAR and the position information of the target point; wherein the position information of the target point comprises: the distance between the target point and the center point of the scene; determining the maximum compensation distance according to the system parameters and the position information of the target point; if the distance between the target point and the center point of the scene is greater than the maximum compensation distance, determining the distance offset caused by the intra-pulse motion according to the position information of the target point, and compensating the position of the target point according to the distance offset; if the distance between the target point and the center point of the scene is not greater than the maximum compensation distance, then not compensating the position of the target point. In the present invention, if the target point is close to the center point of the scene, no compensation is required, so the present invention calculates the maximum compensation distance, and then compensates the position of the target point, which can effectively eliminate the influence of the intra-pulse motion.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a distance offset compensation method and terminal equipment of a frequency modulated continuous wave (CSAR). Background Art

[0002] Frequency Modulated Continuous Wave (FMCW) circular synthetic aperture radar (CSAR), referred to as FMCW CSAR, has no distance blind spot, high accuracy, large bandwidth and low power, and has been widely used.

[0003] In the prior art, the signal characteristics of frequency modulated continuous wave radar are different from those of conventional pulse radar. The duration of the transmitted signal becomes longer and the imaging is affected by the motion within the pulse, thus affecting the accuracy of the radar. Summary of the invention

[0004] The embodiment of the present invention provides a range offset compensation method and terminal device of a frequency modulated continuous wave (CSAR) radar, so as to solve the problem that the frequency modulated continuous wave radar in the prior art does not consider the intra-pulse motion, thus affecting the radar accuracy.

[0005] In a first aspect, an embodiment of the present invention provides a method for compensating for range offset of a frequency modulated continuous wave (CSAR), comprising:

[0006] Obtain the system parameters of the frequency modulated continuous wave (CSAR) and the position information of the target point; wherein the position information of the target point includes: the distance between the target point and the center point of the scene; determine the maximum compensation distance according to the system parameters and the position information of the target point; if the distance between the target point and the center point of the scene is greater than the maximum compensation distance, determine the distance offset caused by the intra-pulse motion according to the position information of the target point, and compensate the position of the target point according to the distance offset; if the distance between the target point and the center point of the scene is not greater than the maximum compensation distance, do not compensate the position of the target point.

[0007] In a second aspect, an embodiment of the present invention provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the distance offset compensation method for the frequency modulated continuous wave CSAR provided in the first aspect or any possible implementation of the first aspect are implemented.

[0008] The embodiment of the present invention provides a distance offset compensation method and terminal device for frequency modulated continuous wave CSAR. The method includes: obtaining the system parameters of frequency modulated continuous wave CSAR and the position information of the target point; wherein the position information of the target point includes: the distance between the target point and the center point of the scene; determining the maximum compensation distance according to the system parameters and the position information of the target point; if the distance between the target point and the center point of the scene is greater than the maximum compensation distance, determining the distance offset caused by the intra-pulse motion according to the position information of the target point, and compensating the position of the target point according to the distance offset; if the distance between the target point and the center point of the scene is not greater than the maximum compensation distance, then the position of the target point is not compensated. In the present invention, if the target point is close to the center point of the scene, no compensation is required, so the present invention calculates the maximum compensation distance, and then compensates the position of the target point, which can effectively eliminate the influence of intra-pulse motion. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, 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 only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0010] Figure 1 It is a flow chart of a method for implementing a range offset compensation method of a frequency modulated continuous wave CSAR provided by an embodiment of the present invention;

[0011] Figure 2 is a distance offset error comparison diagram provided by an embodiment of the present invention;

[0012] Figure 3 It is a structural schematic diagram of a distance offset compensation device for a frequency modulated continuous wave CSAR provided by an embodiment of the present invention;

[0013] Figure 4 It is a schematic diagram of a terminal device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0014] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0015] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0016] See also Figure 1 , which shows a flow chart of the implementation of the distance offset compensation method of the frequency modulated continuous wave CSAR provided by an embodiment of the present invention, which is described in detail as follows:

[0017] The above methods include:

[0018] S101: Acquire system parameters of a frequency modulated continuous wave (CSAR) and location information of a target point; wherein the location information of the target point includes: a distance between the target point and a center point of a scene;

[0019] S102: Determine the maximum compensation distance according to the system parameters and the position information of the target point;

[0020] S103: If the distance between the target point and the center point of the scene is greater than the maximum compensation distance, determine the distance offset caused by the intrapulse motion according to the position information of the target point, and compensate the position of the target point according to the distance offset;

[0021] S104: If the distance between the target point and the center point of the scene is not greater than the maximum compensation distance, the position of the target point is not compensated.

[0022] Figure 2 The schematic diagram of the distance offset error of multiple target points with different distances from the center point of the scene is shown (the horizontal axis is the distance r between the target point and the center point of the scene rp , the vertical axis is the distance offset ΔR caused by the intrapulse motion fτ The ratio of the target point to the carrier wavelength λ); As can be seen from the figure, when the distance between the target point and the center point of the scene (that is, the radial radius of the projection point of the target point on the XOY plane) is 0, the distance offset is always 0 when the target point is located at the center of the observed scene, that is, the target point at the center of the scene is not affected by the intra-pulse motion; when the distance between the target point and the center of the scene is greater than 0, the distance offset changes sinusoidally with slow time, that is, the non-scene center target point is affected by the intra-pulse motion and produces a distance offset, which changes sinusoidally with the change of the platform azimuth observation angle. The greater the distance between the target point and the center point of the scene, the greater the maximum amplitude of the distance offset. It can be seen that the distance offset is related to the distance between the target point and the center point of the scene. At the same time, the distance offset is also related to the inherent parameters of the CSAR system. Generally, when the distance offset is much smaller than the resolution of the CSAR system, the distance offset caused by intrapulse motion can be ignored, and no compensation is required during imaging processing, which will not affect normal imaging. Based on this, the maximum compensation distance is calculated in an embodiment of the present invention. When the distance offset is greater than the maximum compensation distance, compensation for the distance offset caused by intrapulse motion is required during imaging. This can effectively compensate for the error caused by intrapulse motion, thereby improving the accuracy of the CSAR system.

[0023] In a possible implementation, the system parameters of the frequency modulated continuous wave CSAR include: carrier wavelength, linear modulation frequency, flight radius of the carrier platform, platform height, and angular velocity of platform movement; the position information of the target point also includes: the azimuth of the target point; S102 may include:

[0024] S1021: Determine the maximum compensation distance according to the carrier wavelength, the linear modulation frequency, the flight radius of the carrier platform, the platform height, the angular velocity of the platform movement, and the azimuth of the target point.

[0025] In a possible implementation, the maximum compensation distance r rpmax The calculation formula can be:

[0026]

[0027]

[0028] Among them, A is the first coefficient, B is the second coefficient, C is the third coefficient; λ is the carrier wavelength (i.e., CSAR system wavelength), K r is the linear modulation frequency, R xy is the flight radius of the carrier platform, H is the platform height, c is the speed of light, w is the angular velocity of the platform movement, wt is the azimuth observation angle of the platform corresponding to time t, and θ is the azimuth angle of the target point.

[0029] From the performance of the CSAR system, it can be seen that when the range offset is much smaller than the system resolution, no compensation is required during imaging processing, that is:

[0030]

[0031] Among them, ΔR fτ is the distance offset caused by intrapulse motion, Δρ0 is the target resolution at the center of the system scene, and the influence of target height is not considered.

[0032] The calculation formula of the target resolution Δρ0 at the scene center of the frequency modulated continuous wave CSAR system is:

[0033]

[0034] Where, H is the platform height, and λ is the carrier wavelength.

[0035] Substitute formula (4) into formula (3) to obtain formula (5);

[0036]

[0037] set up When the radial radius of the projection point of the target point on the XOY plane (the distance between the target point and the center point of the scene) is r rp =rrpmax , substituting into formula (5), we can get rpmax The quadratic equation

[0038] A.r rpmax 2 +B·r rpmax +C=0 (6)

[0039] Among them, A is the first coefficient, B is the second coefficient, and C is the third coefficient, all of which are related to system parameters and can be expressed as formula (2);

[0040]

[0041] Due to r rpmax ≥0, solving the quadratic equation gives the unique solution formula (1).

[0042]

[0043] Therefore, according to the system parameters: carrier wavelength λ, linear modulation frequency K r , the flight radius R of the aircraft carrier platform xy , platform height H and angular velocity w of platform movement, and the distance between the target point and the center point of the scene, the azimuth angle θ of the target point (i.e. the radial radius of the projection point of the target point on the XOY plane and the rotation angle with the positive semi-axis of the X axis as the reference direction), determine the maximum compensation distance r rpmax When the distance between the target point and the center point of the scene is r rp >r rpmax When the pulse motion is affected, compensation is performed by considering the influence of the pulse motion; otherwise, no compensation is required, which effectively improves the imaging accuracy of the CSAR system.

[0044] In a possible implementation, S103 may include:

[0045] S1031: Determine the distance offset caused by the intra-pulse motion according to the position information of the target point and the system parameters of the frequency modulated continuous wave CSAR.

[0046] The distance offset caused by the intra-pulse motion is affected by the position information of the target and the system parameters. Therefore, in the embodiment of the present invention, it is determined based on the position information of the target point and the system parameters of the frequency modulated continuous wave (CSAR).

[0047] In a possible implementation, S1031 may include:

[0048] 1. Determine the instantaneous slant range of the target that is not affected by fast time based on the position information of the target point and the system parameters of the frequency modulated continuous wave CSAR;

[0049] 2. Determine the distance offset caused by intra-pulse motion based on the instantaneous slant range of the target that is not affected by fast time, the position information of the target point and the system parameters of the frequency-modulated continuous wave CSAR.

[0050] In a possible implementation, the system parameters of the frequency modulated continuous wave CSAR may include: carrier wavelength, linear modulation frequency, flight radius of the carrier platform, platform height, and angular velocity of the platform movement; the location information of the target point may also include: the azimuth of the target point and the height of the target point.

[0051] The circular synthetic aperture radar (CSAR) system transmits a frequency modulated continuous wave (FMCW) signal, and uses a de-linear frequency modulation receiver to remove the residual video phase to obtain the echo signal s r (t,τ):

[0052]

[0053]

[0054] R Δ =R p (t,τ)-R ref (9)

[0055] Among them, t is the slow time; τ is the fast time; σ p is the scattering coefficient of the target point. For an ideal point target, the default value is σ p =1; rect(·) is the rectangular window function, f c is the center frequency of the transmitted signal, K r is the linear modulation frequency, c is the speed of light, T p is the duration of the transmitted signal, u is a variable;

[0056] R p (t,τ) is the instantaneous slant distance of the platform, which can be expressed as formula (10);

[0057]

[0058] R Δ is the slope distance relative to the center of the circle, which can be expressed as formula (11);

[0059] R Δ =R p (t,τ)-R ref (11)

[0060] R ref is the reference slope distance, That is, the slant distance from the center of the scene with a height of 0. p is the height of the target point.

[0061] Taylor expands formula (10) at τ=0, ignoring higher-order terms above the third order, to obtain formula (12).

[0062]

[0063] make Then we get formula (13);

[0064]

[0065] Re-order

[0066]

[0067] Among them, a and b are intermediate parameters.

[0068] Then we get formula (15);

[0069] R Δ ≈R Δm +a·τ+b·τ 2 (15)

[0070] Among them, the instantaneous slant range of the target not affected by the fast time is R Δm for;

[0071]

[0072] Then formula (7) can be rearranged as:

[0073]

[0074] Perform a fast Fourier transform on formula (17) along the fast time τ, and let σ p =1, the envelope function of the signal after distance compression is:

[0075]

[0076] Among them, f τ is the frequency corresponding to the fast time transformation.

[0077] Formula (18) takes into account the influence of intrapulse motion error on frequency offset and main lobe broadening. When the target point is located at the center of the scene, a = 0, Intra-pulse motion errors have no effect on frequency offset and main lobe broadening, and will not cause additional range offset.

[0078] When the target is not in the center of the scene, the frequency offset will introduce additional distance offset. The calculation formula for the distance offset caused by intra-pulse motion is:

[0079]

[0080] From the above analysis, it can be seen that in a possible implementation mode, the instantaneous slant range R of the target not affected by the fast time is Δm The calculation formula can be:

[0081]

[0082] Among them, R xy is the flight radius of the aircraft platform, r rp is the distance between the target point and the center point of the scene, H is the platform height, h p is the height of the target point, w is the angular velocity of the platform, wt is the azimuth observation angle of the platform corresponding to time t, and θ is the azimuth angle of the target point.

[0083] From formula (16), we can see that

[0084] at the same time, Substituting it into formula (16) we get:

[0085]

[0086] Substituting formula (20) into formula (19) yields formula (21).

[0087] In one possible implementation, the distance shift caused by intra-vein motion The calculation formula can be:

[0088]

[0089] Where c is the speed of light, λ is the carrier wavelength, K r is the linear modulation frequency.

[0090] In a possible implementation, the position of the target point I(x p ,y p ) The compensation formula can be:

[0091]

[0092]

[0093] in, is the distance offset caused by the intra-pulse motion, is the echo signal, t is the slow time, τ is the fast time, To transfer the slope distance, is the instantaneous slope distance of the platform, K r is the linear modulation frequency, f c is the center frequency of the transmitted signal, is the angle that the platform rotates at the fast time at time t.

[0094] Need to explain, and R p (t,τ) are the instantaneous slope distances of the platform, only the variables are different, is the angle of the platform turning at the fast time at time t,

[0095] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0096] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0097] Figure 3 The structure diagram of the distance offset compensation device of the frequency modulated continuous wave CSAR provided by the embodiment of the present invention is shown. For the convenience of description, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0098] like Figure 3 As shown, the distance offset compensation device of the frequency modulated continuous wave CSAR includes:

[0099] The parameter acquisition module 21 is used to acquire the system parameters of the frequency modulated continuous wave CSAR and the position information of the target point; wherein the position information of the target point includes: the distance between the target point and the center point of the scene;

[0100] A threshold calculation module 22, used to determine the maximum compensation distance according to system parameters and location information of the target point;

[0101] A first judgment module 23 is used to determine the distance offset caused by the intrapulse motion according to the position information of the target point if the distance between the target point and the center point of the scene is greater than the maximum compensation distance, and compensate the position of the target point according to the distance offset;

[0102] The second judgment module 24 is configured to not compensate the position of the target point if the distance between the target point and the center point of the scene is not greater than the maximum compensation distance.

[0103] In a possible implementation, the system parameters of the frequency modulated continuous wave CSAR may include: carrier wavelength, linear modulation frequency, flight radius of the carrier platform, platform height, and angular velocity of platform movement; the position information of the target point may also include: the azimuth of the target point; the threshold calculation module 22 may include:

[0104] The distance calculation unit is used to determine the maximum compensation distance according to the carrier wavelength, the linear modulation frequency, the flight radius of the carrier platform, the platform height, the angular velocity of the platform movement and the azimuth of the target point.

[0105] In a possible implementation, the maximum compensation distance r rpmax The calculation formula can be:

[0106]

[0107]

[0108] Among them, A is the first coefficient, B is the second coefficient, C is the third coefficient; λ is the carrier wavelength, K r is the linear modulation frequency, R xy is the flight radius of the carrier platform, H is the platform height, c is the speed of light, w is the angular velocity of the platform movement, wt is the azimuth observation angle of the platform corresponding to time t, and θ is the azimuth angle of the target point.

[0109] In a possible implementation, the first determination module 23 may include:

[0110] The offset calculation unit is used to determine the distance offset caused by the intra-pulse motion according to the position information of the target point and the system parameters of the frequency modulated continuous wave CSAR.

[0111] In a possible implementation, the offset calculation unit may include:

[0112] The normal slant range calculation subunit is used to determine the instantaneous slant range of the target that is not affected by the fast time according to the position information of the target point and the system parameters of the frequency modulated continuous wave CSAR;

[0113] The offset output subunit is used to determine the distance offset caused by intra-pulse motion based on the target instantaneous slant range not affected by fast time, the position information of the target point and the system parameters of the frequency modulated continuous wave CSAR.

[0114] In a possible implementation, the system parameters of the frequency modulated continuous wave CSAR may include: carrier wavelength, linear modulation frequency, flight radius of the carrier platform, platform height, and angular velocity of the platform movement; the location information of the target point may also include: the azimuth of the target point and the height of the target point.

[0115] In a possible implementation, the target instantaneous slant range R that is not affected by the fast time is Δm The calculation formula can be:

[0116]

[0117] Among them, R xy is the flight radius of the aircraft platform, r rp is the distance between the target point and the center point of the scene, H is the platform height, h pis the height of the target point, w is the angular velocity of the platform, wt is the azimuth observation angle of the platform corresponding to time t, and θ is the azimuth angle of the target point.

[0118] In one possible implementation, the distance shift caused by intra-vein motion The calculation formula can be:

[0119]

[0120] Where c is the speed of light, λ is the carrier wavelength, K r is the linear modulation frequency.

[0121] In a possible implementation, the position of the target point I(x p ,y p ) The compensation formula can be:

[0122]

[0123]

[0124] in, is the distance offset caused by the intra-pulse motion, is the echo signal, t is the slow time, τ is the fast time, To transfer the slope distance, is the instantaneous slope distance of the platform, K r is the linear modulation frequency, f c is the center frequency of the transmitted signal, is the angle that the platform rotates at the fast time at time t.

[0125] Figure 4 Schematic diagram of a terminal device 3 provided in an embodiment of the present invention. Figure 4 As shown, the terminal device 3 of this embodiment includes: a processor 30 and a memory 31. The memory 31 is used to store a computer program 32, and the processor 30 is used to call and run the computer program 32 stored in the memory 31 to perform the steps in the above-mentioned embodiments of the range offset compensation method of each frequency modulated continuous wave CSAR, for example Figure 1 Alternatively, the processor 30 is used to call and run the computer program 32 stored in the memory 31 to implement the functions of each module / unit in the above-mentioned device embodiments, such as Figure 3 The functions of modules 21 to 24 are shown.

[0126] Exemplarily, the computer program 32 may be divided into one or more modules / units, one or more modules / units are stored in the memory 31, and are executed by the processor 30 to implement the present invention. One or more modules / units may be a series of computer program instruction segments that can implement specific functions, and the instruction segments are used to describe the execution process of the computer program 32 in the terminal device 3. For example, the computer program 32 may be divided into Figure 3 Modules / units 21 to 24 are shown.

[0127] The terminal device 3 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The terminal device 3 may include, but is not limited to, a processor 30 and a memory 31. Those skilled in the art will appreciate that Figure 4 It is only an example of terminal device 3 and does not constitute a limitation on terminal device 3. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and output devices, network access devices, buses, etc.

[0128] The processor 30 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0129] The memory 31 may be an internal storage unit of the terminal device 3, such as a hard disk or memory of the terminal device 3. The memory 31 may also be an external storage device of the terminal device 3, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal device 3. Further, the memory 31 may also include both an internal storage unit and an external storage device of the terminal device 3. The memory 31 is used to store computer programs and other programs and data required by the terminal. The memory 31 may also be used to temporarily store data that has been output or is to be output.

[0130] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0131] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0132] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0133] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0134] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0135] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0136] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. Computer-readable media may include: any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc.

[0137] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such 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, and should be included in the protection scope of the present invention.

Claims

1. A method for compensating distance offset of frequency modulated continuous wave CSAR, characterized in that: include: Acquire the system parameters of the frequency modulated continuous wave (CSAR) and the location information of the target point; wherein the location information of the target point includes: the distance between the target point and the center point of the scene; Determine the maximum compensation distance according to the system parameters and the position information of the target point; If the distance between the target point and the center point of the scene is greater than the maximum compensation distance, determining the distance offset caused by the intrapulse motion according to the position information of the target point, and compensating the position of the target point according to the distance offset; If the distance between the target point and the center point of the scene is not greater than the maximum compensation distance, the position of the target point is not compensated; The system parameters of the frequency modulated continuous wave CSAR include: carrier wavelength, linear modulation frequency, flight radius of the carrier platform, platform height, and angular velocity of platform movement; the position information of the target point also includes: the azimuth of the target point; The maximum compensation distance r rpmax The calculation formula is: Wherein, A is the first coefficient, B is the second coefficient, C is the third coefficient; λ is the carrier wavelength, K r is the linear modulation frequency, R xy is the flight radius of the carrier platform, H is the height of the platform, c is the speed of light, w is the angular velocity of the platform movement, wt is the azimuth observation angle of the platform corresponding to time t, and θ is the azimuth angle of the target point.

2. The distance offset compensation method of frequency modulated continuous wave CSAR according to claim 1, characterized in that: The step of determining the distance offset caused by the intrapulse motion according to the position information of the target point comprises: The distance offset caused by the intra-pulse motion is determined according to the position information of the target point and the system parameters of the frequency modulated continuous wave (CSAR).

3. The distance offset compensation method of frequency modulated continuous wave CSAR according to claim 2, characterized in that: Determining the distance offset caused by the intra-pulse motion according to the position information of the target point and the system parameters of the frequency modulated continuous wave CSAR includes: Determine the instantaneous slant range of the target that is not affected by fast time according to the position information of the target point and the system parameters of the frequency modulated continuous wave CSAR; The distance offset caused by the intra-pulse motion is determined according to the instantaneous slant range of the target not affected by the fast time, the position information of the target point and the system parameters of the frequency modulated continuous wave CSAR.

4. The distance offset compensation method of frequency modulated continuous wave CSAR according to claim 3, characterized in that: The system parameters of the frequency modulated continuous wave CSAR include: carrier wavelength, linear modulation frequency, flight radius of the carrier platform, platform height, and angular velocity of platform movement; the position information of the target point also includes: the azimuth of the target point and the height of the target point.

5. The distance offset compensation method of frequency modulated continuous wave CSAR according to claim 4, characterized in that: The instantaneous slant range R of the target not affected by the fast time Δm The calculation formula is: Among them, R xy is the flight radius of the aircraft carrier platform, r rp is the distance between the target point and the center point of the scene, H is the height of the platform, h p is the height of the target point, w is the angular velocity of the platform movement, wt is the azimuth observation angle of the platform corresponding to time t, and θ is the azimuth angle of the target point.

6. The distance offset compensation method of frequency modulated continuous wave CSAR according to claim 5, characterized in that: The distance shift caused by the intra-vein motion The calculation formula is: Where c is the speed of light, λ is the carrier wavelength, K r is the linear modulation frequency.

7. The distance offset compensation method of frequency modulated continuous wave CSAR according to any one of claims 1 to 6, characterized in that: The position I(x) of the target point is adjusted according to the distance offset p ,y p ) is compensated by: in, is the distance offset caused by the intra-pulse motion, is the echo signal, t is the slow time, τ is the fast time, To transfer the slope distance, is the instantaneous slope distance of the platform, K r is the linear modulation frequency, f c is the center frequency of the transmitted signal, is the angle that the platform rotates at the fast time at time t.

8. A terminal device, characterized in that: The invention comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the steps of the distance offset compensation method of frequency modulated continuous wave CSAR according to any one of claims 1 to 7.

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