A Doppler Phase Compensation Method and System Based on Inverted Slant Range Model

Abstract

This invention provides a Doppler phase compensation method and system based on an inverted slant range model, belonging to the field of synthetic aperture radar imaging technology. The method includes: locating scene targets based on a priori digital elevation models to determine the target point position; inverting the numerical slant range history of the target point position based on satellite orbit information; comparing the numerical slant range history with the analytical slant range history to obtain the difference in slant range history; and performing phase compensation in the echo domain and Doppler domain based on the difference in slant range history to complete focusing. By compensating for the difference between the numerical slant range history and the analytical slant range history in the echo domain and the image Doppler domain respectively, the method considers the influence of areas with large elevation fluctuations in the imaging scene, resulting in superior focusing performance and effectively solving the problem of focusing performance degradation.

Description

Technical Field

[0001] This invention relates to the field of synthetic aperture radar imaging technology, and in particular to a Doppler phase compensation method and system based on an inverted slant range model. Background Technology

[0002] Synthetic Aperture Radar (SAR) is a microwave imaging radar system. Compared to traditional radar, it overcomes the limitations of physical antenna size through synthetic aperture technology, achieving high-resolution observation. Compared to the passive remote sensing of optical radar, it actively transmits and receives backscattered coherent electromagnetic wave signals from the target, simultaneously acquiring the target's scattering intensity, phase, polarization characteristics, and motion parameters (such as Doppler shift and time delay information). This multidimensional information gives SAR images unique advantages in applications such as target feature inversion, ground feature classification and identification, and quantitative analysis. Furthermore, due to the penetrating power of microwaves through clouds, water vapor, and some ground features, SAR possesses all-weather, all-day imaging capabilities, compensating for the observation limitations of optical remote sensing in harsh environments.

[0003] SAR, with its all-weather, all-day observation capabilities and multi-dimensional information inversion advantages, has become a core sensor in space-based Earth observation systems. This technology is irreplaceable in areas such as disaster emergency response, dynamic monitoring of land resources, and strategic intelligence acquisition. High-resolution and wide-swath (HRWS) imaging has always been a core objective of SAR system design; however, traditional single-channel systems are limited by the inherent contradiction of azimuth / range ambiguity, making it difficult to balance resolution and mapping bandwidth. Multi-channel SAR expands its performance boundaries by increasing the degrees of freedom in spatial sampling; however, issues such as channel errors, computational efficiency, and slant range model mismatch still restrict its engineering applications.

[0004] Therefore, how to solve the focusing performance degradation problem of high-resolution imaging algorithms based on analytical equivalent slant range models in areas with large elevation fluctuations, which has been exposed in the current engineering application of spaceborne HRWS SAR signal processing, has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a Doppler phase compensation method and system based on an inverted slant range model, which solves the defect of focusing performance degradation in existing high-resolution imaging algorithms based on analytical equivalent slant range models in areas with large elevation fluctuations.

[0006] In a first aspect, the present invention provides a Doppler phase compensation method based on an inverted slant range model, comprising:

[0007] Scene target localization is performed based on a priori digital elevation model to determine the location of target points;

[0008] The numerical slant range history of the target point's location was retrieved based on satellite orbit information;

[0009] The numerical slant range history is compared with the analytical slant range history to obtain the difference in slant range history.

[0010] Based on the difference in slant range history, phase compensation in the echo domain and Doppler domain is performed on the inverted numerical slant range history to complete focusing.

[0011] According to the present invention, a Doppler phase compensation method based on an inversion slant range model is provided, wherein scene target localization based on a priori digital elevation model to determine the target point position includes:

[0012] Input the satellite position, velocity, slant range, and Doppler information corresponding to the imaging time period into the positioning equation set;

[0013] Using a priori digital elevation model, the target point position in the WGS84 coordinate system is solved by iterating the initial elevation of the target point in the positioning equation set.

[0014] According to the present invention, a Doppler phase compensation method based on an inversion slant range model is provided, wherein the numerical slant range history of the target point position is inverted based on satellite orbit information, comprising:

[0015] Determine the timing of each SAR transmission pulse, as well as the transmission location and velocity;

[0016] Through iterative search, the time, position, and velocity of each transmitted pulse are made to satisfy the preset conditions based on the target point position, along with the corresponding pulse received time, position, and velocity.

[0017] Based on the results of the iterative convergence, the two-way slant range and two-way Doppler frequency corresponding to each transmission pulse moment are obtained;

[0018] Based on the two-way slant range, the two-way Doppler frequency, and the transmission pulse time, a mapping relationship between the numerical slant range history and the Doppler frequency is established.

[0019] According to the present invention, a Doppler phase compensation method based on an inversion slant range model is provided, wherein the iterative search includes:

[0020] The initial values ​​are determined based on the nearest slant distance and the speed of light in the illuminated scene;

[0021] Based on the initial value, determine the arbitrary pulse reception time and interpolate the corresponding reception position and reception speed;

[0022] Input the receiving position, the receiving speed, and the target point position into the time delay error formula to obtain the time delay error;

[0023] If the time delay error is less than the corresponding iteration threshold, the iteration is terminated; otherwise, the arbitrary pulse reception time is updated.

[0024] According to the present invention, a Doppler phase compensation method based on an inverted slant range model is provided, wherein comparing the numerical slant range history with the analytical slant range history to obtain the difference in slant range history includes:

[0025] Determine the model difference between the numerical slope distance history and the slope distance history of the hyperbolic analytical slope distance model;

[0026] Based on the model difference, determine the consistent slant range history difference for all scattering points;

[0027] The difference between the consistent slant range history difference and the slant range history difference of each scattering point is determined to obtain the differential slant range history difference.

[0028] According to the present invention, a Doppler phase compensation method based on an inverted slant range model is provided, wherein phase compensation in the echo domain and Doppler domain is performed on the inverted numerical slant range history based on the difference in slant range history, comprising:

[0029] Based on the SAR principle, the echo domain phase compensation is performed on the echo domain echo expression of the retrieved numerical slant range history using the model difference and the difference in slant range history.

[0030] Phase compensation is performed in the Doppler domain on the echo data after phase compensation in the echo domain.

[0031] According to the present invention, a Doppler phase compensation method based on an inverted slant range model is provided, wherein the echo domain phase compensation is performed on the echo domain echo expression of the inverted numerical slant range history using the model difference and the difference in slant range history, including:

[0032] Based on SAR principles, the echo domain echo expression based on the inverted slant range history is determined.

[0033] Input the model difference and the difference slant range history difference into the echo domain echo expression in sequence to obtain the echo domain phase compensation expression;

[0034] Based on the echo domain phase compensation expression, the echo domain compensation phase is determined.

[0035] According to the present invention, a Doppler phase compensation method based on an inversion slant range model is provided, wherein the phase compensation of the echo data after phase compensation in the echo domain is performed in the Doppler domain, comprising:

[0036] Determine the echo expression of the echo data after phase compensation in the echo domain in the Doppler domain;

[0037] After performing frequency domain focusing imaging on the echo expression in the Doppler domain, Doppler compensation is performed to obtain the analytical expression in the range-Doppler domain.

[0038] Based on the range-Doppler domain analytical expression, after determining the Doppler compensation phase, an inverse Fourier transform of the azimuth is performed to complete focusing.

[0039] Secondly, the present invention provides a Doppler phase compensation system based on an inverted slant range model, comprising:

[0040] The positioning module is used to locate scene targets based on a prior digital elevation model and determine the location of target points.

[0041] The inversion module is used to invert the numerical slant range history of the target point's location based on satellite orbit information;

[0042] The comparison module is used to compare the numerical slant range history with the analytical slant range history to obtain the difference in slant range history.

[0043] The compensation module is used to perform Doppler phase compensation on the echo domain echo of the inverted slant range history based on the difference in slant range history, thereby completing the focusing.

[0044] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the Doppler phase compensation method based on the inversion slant range model as described above.

[0045] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the Doppler phase compensation method based on the inversion slant range model as described above.

[0046] Fifthly, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the Doppler phase compensation method based on the inversion slant range model as described above.

[0047] This invention provides a Doppler phase compensation method and system based on an inverted slant range model. The method includes: locating the target point in a scene based on a priori digital elevation model; inverting the numerical slant range history of the target point based on satellite orbit information; comparing the numerical slant range history with the analytical slant range history to obtain the difference in slant range history; and performing phase compensation in the echo domain and Doppler domain on the inverted numerical slant range history based on the difference in slant range history to achieve focusing. By compensating for the difference between the numerical slant range history and the analytical slant range history in the echo domain and the image Doppler domain respectively, the method considers the influence of areas with large elevation fluctuations in the imaging scene, resulting in superior focusing performance and effectively solving the problem of focusing performance degradation. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0049] Figure 1 This is a flowchart illustrating the Doppler phase compensation method based on the inversion slant range model provided in this embodiment;

[0050] Figure 2 This is a comparison chart of the inverted slant range values ​​provided in this embodiment and the simulation results of the traditional hyperbolic slant range model;

[0051] Figure 3 This embodiment provides a schematic diagram comparing the focusing results of the traditional hyperbolic slant range model with the focusing results of the inverted slant range model proposed in this application after azimuth Doppler phase compensation;

[0052] Figure 4 This is an image detail of target 2 provided in this embodiment;

[0053] Figure 5 This is a schematic diagram of the Doppler phase compensation system based on the inversion slant range model provided in this embodiment;

[0054] Figure 6 This is a schematic diagram of the structure of the electronic device provided in this embodiment. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0056] Figure 1 This is a flowchart illustrating the Doppler phase compensation method based on the inversion slant range model provided in this embodiment.

[0057] like Figure 1 As shown, the Doppler phase compensation method based on the inversion slant range model provided in this embodiment of the invention mainly includes the following steps:

[0058] 101. Based on the prior digital elevation model, the scene target is located to determine the position of the target point.

[0059] Specifically, the satellite position information, velocity information, slant range information, and Doppler information corresponding to the imaging time period are input into the positioning equation set, as shown in equation (1):

[0060] (1)

[0061] in, For satellite position, The target point location, The slope vector of the radar reaching the target point. The magnitude of the slope moment vector. The velocity vector of the radar relative to the target point. The center frequency of the Doppler wave. The radius is the equatorial radius. The polar radius, Let be the initial elevation of the target point. The initial position of the target point can be obtained by solving the above system of equations using Newton-Raphson iteration.

[0062] For targets on the sea surface, the initial elevation of the initial target point can be set to 0. However, for targets with significant elevation fluctuations in the scene, a prior Digital Elevation Model (DEM) can be used to iteratively correct the elevation values. It can obtain more precise target point locations in the scene. This gives us the target point position of the scene target in the WGS84 coordinate system.

[0063] 102. Numerical slant range history of target point location inversion based on satellite orbit information.

[0064] Specifically, for each transmission pulse time of SAR and the radar's launch location at that moment. and launch speed Each has a unique pulse reception time. and the radar's receiving position at that moment. and receiving speed Through iterative search This ensures that the target point meets the preset conditions based on its location, such as (2):

[0065] (2)

[0066] Where c is the speed of light.

[0067] The specific process of iterative search is as follows:

[0068] Initial values ​​are determined based on the nearest slant distance and the speed of light in the illumination scene. For example (3):

[0069] (3)

[0070] in, is the nearest slant range of the illuminated scene, which is a known parameter in SAR missions, and C is the speed of light.

[0071] Based on initial value and Determine the timing of arbitrary pulse reception And interpolate the corresponding receiving position. and receiving speed and For example (4):

[0072] (4)

[0073] Input the receiving location, receiving speed, and target point location into the time delay error formula to obtain the time delay error. For example, in formula (5):

[0074] (5)

[0075] Time delay error If the delay error is compared with a pre-set iteration threshold, the iteration ends; otherwise, the arbitrary pulse reception time is updated. Repeat the above steps until the time delay error is less than the corresponding iteration threshold.

[0076] Based on the results of the iterative convergence, the timing of each transmitted pulse can be obtained. Corresponding two-way slope distance and two-way Doppler frequency For example, (6) and (7):

[0077] (6)

[0078] (7)

[0079] in, This refers to the radar wavelength.

[0080] With Doppler frequency The two satisfy a one-to-one mapping, therefore, by means of Numerical slant range history can be established. With Doppler frequency The mapping relationship between them.

[0081] 103. Compare the numerical slant range history with the analytical slant range history to obtain the difference in slant range history.

[0082] Figure 2 This is a comparison chart of the numerical inversion slant range provided in this embodiment and the simulation results of the traditional hyperbolic slant range model. The simulation results of the numerical slant range history of a target point in the scene and the slant range history of the traditional hyperbolic analytical slant range model are shown below. Figure 2 As shown, from Figure 2 As can be seen, the calculation results of the two models are consistent, thus determining the model difference between the two models as follows: Then we have (8):

[0083] (8)

[0084] in, This is obtained from the inverted numerical slant range history. This was obtained using a hyperbolic slope distance model. This refers to the direction of time.

[0085] The reason for this discrepancy is that the satellite platform's flight trajectory is not strictly a uniform straight line. Therefore, it is possible to infer all scattering points in the illuminated scene. There exists a difference in slant range history that is only related to the satellite orbit and not to the scattering point. The position-independent component is called the uniform slant range history difference. This value is only related to time and defines the slant range history difference at each scattering point. Difference with consistent slant distance history The difference between them is the difference in slant distance history. Then we have (9):

[0086] (9)

[0087] This difference This is caused by a combination of factors, including the different elevations of the scattering points.

[0088] 104. Based on the difference in slant range history, phase compensation in the echo domain and Doppler domain is performed on the inverted numerical slant range history to complete focusing.

[0089] Based on the working principle of SAR, the echo domain echo expression based on the inverted slant range history can be derived, as shown in (10):

[0090] (10)

[0091] in, For distance to time, To adjust the frequency, The pulse width. For carrier frequency, This is the azimuth angle.

[0092] Will Substituting into equation (10) above, we get (11):

[0093] (11)

[0094] in, The magnitude of the time is generally sub-centimeter, which is much smaller than the sub-meter range resolution. Therefore, its delay in the range direction can be ignored, so the above formula can be written as (12):

[0095] (12)

[0096] Will Substituting into equation (12) above, we get (13):

[0097] (13)

[0098] The last term in equation (13) above is the consistent slant range difference term, which is independent of the target point and can be directly used as the echo domain phase error compensation. The echo domain compensation phase is (14):

[0099] (14)

[0100] in, The angle of view at the beam center. This represents the equivalent velocity of the radar platform corresponding to the center point of the scene. Compensation. The echo expression for the subsequent echo data in the range-Doppler domain is (15):

[0101] (15)

[0102] in: (16)

[0103] in, For target point The shortest one-way slant range to the radar platform. For radar at the target point The equivalent speed at that point.

[0104] compensate The subsequent echo data is then imaged using a traditional imaging algorithm. Depending on the SAR operating mode, a matching frequency domain imaging algorithm can be used. After focusing and imaging using a traditional frequency domain algorithm, due to the existence of a difference in slant range history, the focused image will appear slightly defocused in the azimuth direction of the image domain. It is necessary to compensate for the Doppler phase term corresponding to the difference in slant range history in the Doppler domain. At this time, the distance Doppler domain analytical expression of a certain scattering point is expressed as (17):

[0105] (17)

[0106] in, For azimuth bandwidth, The center frequency of the Doppler wave. The zero Doppler moment.

[0107] After compensating for the phase of equation (18), precise focusing can be achieved by performing an inverse Fourier transform of the azimuth.

[0108] (18)

[0109] This embodiment proposes a fine-focusing Doppler phase compensation method in the azimuth direction, using the difference between the numerical slant range history and the analytical slant range history as the phase error to compensate in both the echo domain and the image Doppler domain. This method considers the influence of target elevation fluctuations in the imaging scene and exhibits superior focusing performance. It provides a new focusing processing approach for current high-resolution wide-swath SAR imaging processing, which can promote further applications of SAR data, such as subsequent target information extraction and detection.

[0110] Furthermore, using simulated echo data of SAR point targets in sliding spotting mode, three point targets are evenly distributed in the scene and have different elevation values. The focusing results of the traditional hyperbolic slant range model and the focusing results of the inverted slant range model proposed in this embodiment after azimuth Doppler phase compensation are compared as follows: Figure 3 As shown, the imaging detail of target 2 is as follows: Figure 4 As shown in Table 1, the quantitative evaluation results of the three targets are verified by comparing the imaging quality (resolution, peak sidelobe ratio, and integral sidelobe ratio) of the point targets.

[0111] Table 1

[0112]

[0113] This application constructs a numerical slant range model accurate to the sub-centimeter level by combining satellite platform position and velocity information with global prior DEM data (depending on satellite orbit determination accuracy and DEM accuracy). It innovatively decomposes the slant range model error into two steps: echo domain phase compensation and image Doppler domain spatial variation correction. Experimental simulations demonstrate that this algorithm significantly improves focusing performance in areas with significant terrain undulations, and even in flat areas, its focusing is superior to traditional algorithms.

[0114] Based on the same general inventive concept, this invention also protects a schematic diagram of a Doppler phase compensation system based on an inversion slant range model. The schematic diagram of the Doppler phase compensation system based on an inversion slant range model described below can be referred to in correspondence with the schematic diagram of the Doppler phase compensation system based on an inversion slant range model described above.

[0115] Figure 5 This is a schematic diagram of the Doppler phase compensation system based on the inversion slant range model provided in this embodiment.

[0116] like Figure 5 As shown, this embodiment provides a Doppler phase compensation system based on an inversion slant range model, comprising:

[0117] The positioning module 501 is used to locate scene targets based on a prior digital elevation model and determine the location of target points.

[0118] Inversion module 502 is used to invert the numerical slant range history of the target point position based on satellite orbit information;

[0119] Comparison module 503 is used to compare the numerical slant range history with the analytical slant range history to obtain the difference in slant range history.

[0120] The compensation module 504 is used to perform Doppler phase compensation on the echo domain echo of the inverted slant range history based on the difference in slant range history, thereby completing the focusing.

[0121] Figure 6 This is a schematic diagram of the structure of the electronic device provided in this embodiment.

[0122] like Figure 6As shown, the electronic device may include a processor 610, a communication interface 620, a memory 630, and a communication bus 640. The processor 610, communication interface 620, and memory 630 communicate with each other via the communication bus 640. The processor 610 can call logical instructions in the memory 630 to execute a Doppler phase compensation method based on an inverted slant range model. This method includes: locating the target point based on a priori digital elevation model; inverting the numerical slant range history of the target point based on satellite orbit information; comparing the numerical slant range history with the analytical slant range history to obtain the difference in slant range history; and performing echo domain and Doppler domain phase compensation on the inverted numerical slant range history based on the difference in slant range history to achieve focusing.

[0123] Furthermore, the logical instructions in the aforementioned memory 630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0124] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the Doppler phase compensation method based on the inversion slant range model provided by the above methods. The method includes: performing scene target localization based on a priori digital elevation model to determine the target point position; inverting the numerical slant range history of the target point position based on satellite orbit information; comparing the numerical slant range history with the analytical slant range history to obtain the difference in slant range history; and performing phase compensation in the echo domain and Doppler domain on the inverted numerical slant range history based on the difference in slant range history to complete focusing.

[0125] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements the Doppler phase compensation method based on the inversion slant range model provided by the above methods. The method includes: locating a scene target based on a priori digital elevation model to determine the position of the target point; inverting the numerical slant range history of the target point position based on satellite orbit information; comparing the numerical slant range history with the analytical slant range history to obtain the difference in slant range history; and performing phase compensation in the echo domain and Doppler domain on the inverted numerical slant range history based on the difference in slant range history to complete focusing.

[0126] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0127] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A Doppler phase compensation method based on an inverted slant range model, characterized in that, include: Scene target localization is performed based on a priori digital elevation model to determine the location of target points; The numerical slant range history of the target point's location was retrieved based on satellite orbit information; Determine the model difference between the numerical slope distance history and the slope distance history of the hyperbolic analytical slope distance model; Based on the model difference, the consistent slant range history difference of all scattering points is determined; the consistent slant range history difference is a component that is independent of the location of the scattering point. The difference between the consistent slant range history difference and the model difference is determined to obtain the differential slant range history difference; Based on the consistent slant range history difference and the differential slant range history difference, phase compensation is performed in the echo domain and Doppler domain on the retrieved numerical slant range history to complete focusing.

2. The Doppler phase compensation method based on the inversion slant range model according to claim 1, characterized in that, The process of locating scene targets based on prior digital elevation models and determining the location of target points includes: Input the satellite position, velocity, slant range, and Doppler information corresponding to the imaging time period into the positioning equation set; Using a priori digital elevation model, the target point position in the WGS84 coordinate system is solved by iterating the initial elevation of the target point in the positioning equation set.

3. The Doppler phase compensation method based on the inversion slant range model according to claim 1, characterized in that, The numerical slant range history for retrieving the target point's location based on satellite orbit information includes: Determine the timing of each SAR transmission pulse, as well as the transmission location and transmission velocity; Through iterative search, the time, position, and velocity of each transmitted pulse are made to satisfy the preset conditions based on the target point position, along with the corresponding pulse received time, position, and velocity. Based on the results of the iterative convergence, the two-way slant range and two-way Doppler frequency corresponding to each transmission pulse moment are obtained; Based on the two-way slant range, the two-way Doppler frequency, and the transmission pulse time, a mapping relationship between the numerical slant range history and the Doppler frequency is established.

4. The Doppler phase compensation method based on the inversion slant range model according to claim 3, characterized in that, The iterative search includes: The initial values ​​are determined based on the nearest slant distance and the speed of light in the illuminated scene; Based on the initial value, determine the arbitrary pulse reception time and interpolate the corresponding reception position and reception speed; Input the receiving position, the receiving speed, and the target point position into the time delay error formula to obtain the time delay error; If the time delay error is less than the corresponding iteration threshold, the iteration is terminated; otherwise, the arbitrary pulse reception time is updated.

5. The Doppler phase compensation method based on the inversion slant range model according to claim 1, characterized in that, Based on the consistent slant range history difference, echo domain phase compensation is performed on the echo domain echo expression of the inverted numerical slant range history, including: Based on SAR principles, the echo domain echo expression based on the inverted slant range history is determined. Input the model difference and the difference slant range history difference into the echo domain echo expression in sequence to obtain the echo domain phase compensation expression; Based on the echo domain phase compensation expression, the echo domain compensation phase is determined.

6. The Doppler phase compensation method based on the inversion slant range model according to claim 5, characterized in that, The phase compensation of the echo data after phase compensation in the echo domain is performed in the Doppler domain, including: Determine the echo expression of the echo data after phase compensation in the echo domain in the Doppler domain; After performing frequency domain focusing imaging on the echo expression in the Doppler domain, Doppler compensation is performed to obtain the analytical expression in the range-Doppler domain. Based on the range-Doppler domain analytical expression, after determining the Doppler compensation phase, an inverse Fourier transform of the azimuth is performed to complete focusing.

7. A Doppler phase compensation system based on an inversion slant range model, characterized in that, include: The positioning module is used to locate scene targets based on a prior digital elevation model and determine the location of target points. The inversion module is used to invert the numerical slant range history of the target point's location based on satellite orbit information; The comparison module determines the model difference between the numerical slope distance history and the slope distance history of the hyperbolic analytical slope distance model. Based on the model difference, the consistent slant range history difference of all scattering points is determined; the consistent slant range history difference is a component that is independent of the location of the scattering point. The difference between the consistent slant range history difference and the model difference is determined to obtain the differential slant range history difference; The compensation module performs phase compensation in the echo domain and Doppler domain on the retrieved numerical slant range history based on the consistent slant range history difference and the differential slant range history difference, respectively, to complete focusing.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the Doppler phase compensation method based on the inversion slant range model as described in any one of claims 1 to 6.

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