Doppler phase compensation method and system based on inversion slope distance model

Abstract

The invention provides a Doppler phase compensation method and system based on an inversion slope distance model, and belongs to the technical field of synthetic aperture radar imaging, and the method comprises the steps: carrying out the scene target positioning based on a prior digital elevation model, and determining the position of a target point; inverting a numerical slant range course of a target point position based on satellite orbit information; comparing the numerical slant range history with the analysis slant range history to obtain a difference slant range history difference; phase compensation of an echo domain and a Doppler domain is carried out on the inverted numerical value slant range process based on the difference slant range process difference, focusing is completed, the difference value between the numerical value slant range process and the analysis slant range process is compensated in the echo domain and the image Doppler domain, the influence of the area with the large target elevation fluctuation in the imaging scene is considered, and the target elevation fluctuation of the target in the imaging scene is improved. And the focusing performance is better, and the problem of focusing performance degradation is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of synthetic aperture radar imaging technology, and in particular to a Doppler phase compensation method and system based on an inversion slant range model. BACKGROUND

[0002] Synthetic Aperture Radar (SAR) is a kind of microwave imaging radar system. Compared with traditional radar, it breaks through the physical antenna size limit through synthetic aperture technology to realize high-resolution observation. Compared with passive remote sensing of optical radar, it can synchronously obtain the scattering intensity, phase, polarization characteristics and motion parameters (such as Doppler frequency shift and time delay information) of the target by actively transmitting and receiving the backscattering phase electromagnetic wave signals from the target. These multi-dimensional information makes the SAR image show unique advantages in target feature inversion, ground feature classification and identification, and quantitative analysis. In addition, due to the penetration ability of microwave to clouds, water vapor and some ground objects, SAR has all-weather and all-day imaging characteristics, which makes up for the observation limitations of optical remote sensing in harsh environments.

[0003] SAR has become a core sensor in the space-to-earth observation system due to its all-weather and all-day observation capability and multi-dimensional information inversion advantage. The technology has irreplaceability in disaster emergency response, dynamic monitoring of land resources and strategic intelligence acquisition. High-resolution and wide-swath (HRWS) imaging has always been the core goal of SAR system design, but the traditional single-channel system is difficult to balance resolution and swath width due to the inherent contradiction between azimuth / distance ambiguity. Multi-channel SAR expands the performance boundary by increasing the spatial sampling degree of freedom, but channel error, computational efficiency and slant range model mismatch still restrict its engineering application.

[0004] Therefore, how to solve the problem that the high-resolution imaging algorithm based on the analytical equivalent slant range model in the current spaceborne HRWS SAR signal processing engineering application has focusing performance degradation in the area with large height fluctuation has become a technical problem that the technical personnel in the field need to solve urgently. SUMMARY

[0005] The present application provides a Doppler phase compensation method and system based on an inversion slant range model to solve the defect that the high-resolution imaging algorithm based on the analytical equivalent slant range model in the prior art has focusing performance degradation in the area with large height fluctuation.

[0006] In a first aspect, the present application provides a Doppler phase compensation method based on an inversion slant range model, comprising: locating the scene target based on the prior digital elevation model to determine the target point position; inversion of the target point position based on satellite orbit information; comparing the numerical range history with an analytical range history to obtain a difference range history difference; Based on the difference range history difference, the inverted numerical range history is compensated in the echo domain and the Doppler domain, and focusing is completed.

[0007] According to the present application, a Doppler phase compensation method based on an inversion range model is provided, which is based on a priori digital elevation model for scene target positioning, and determines the target point position, comprising: Input the corresponding satellite position information, velocity information, range information and Doppler information in the imaging time period into the positioning equation set; Using the a priori digital elevation model, the initial elevation of the target point in the positioning equation set is iterated to solve the target point position of the scene target in the WGS84 coordinate system.

[0008] According to the present application, a Doppler phase compensation method based on an inversion range model is provided, which is based on satellite orbit information to invert the numerical range history of the target point position, comprising: Determine the transmission position and transmission speed of each transmission pulse moment of SAR; Through iterative search, the transmission position and transmission speed of each transmission pulse moment and the corresponding pulse reception moment and reception position and reception speed satisfy the preset condition based on the target point position; Based on the results of the iterative convergence, the two-way range and two-way Doppler frequency corresponding to each transmission pulse moment are obtained; Based on the two-way range and two-way Doppler frequency and the transmission pulse moment, a mapping relationship between the numerical range history and the Doppler frequency is established.

[0009] According to the present application, a Doppler phase compensation method based on an inversion range model is provided, which comprises: Determine the initial value based on the nearest range of the irradiation scene and the speed of light; Based on the initial value, determine an arbitrary pulse reception moment, and interpolate the corresponding reception position and reception speed; Input the reception position, the reception 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 exited, otherwise the arbitrary pulse reception moment is updated.

[0010] According to the present application, a Doppler phase compensation method based on an inversion range model is provided, which comprises: determining a model difference between the numerical slant range history and a slant range history of a hyperbolic analytical slant range model; determining a consistent slant range history difference of all scattering points based on the model difference; determining a difference between the consistent slant range history difference and the slant range history difference of each scattering point to obtain a difference slant range history difference.

[0011] According to the present application, a Doppler phase compensation method based on an inversion slant range model is provided, and the numerical slant range history obtained by inversion is compensated in the echo domain and the Doppler domain based on the difference slant range history difference, including: Based on the SAR principle, the echo domain echo expression of the numerical slant range history obtained by inversion is compensated in the echo domain based on the model difference and the difference slant range history difference; The echo data compensated in the echo domain is compensated in the Doppler domain.

[0012] According to the present application, a Doppler phase compensation method based on an inversion slant range model is provided, and the numerical slant range history obtained by inversion is compensated in the echo domain and the Doppler domain based on the difference slant range history difference, including: Based on the SAR principle, the echo domain echo expression of the numerical slant range history obtained by inversion is compensated in the echo domain based on the model difference and the difference slant range history difference; The model difference and the difference slant range history difference are sequentially input to the echo domain echo expression to obtain an echo domain phase compensation expression; Based on the echo domain phase compensation expression, an echo domain compensation phase is determined.

[0013] According to the present application, a Doppler phase compensation method based on an inversion slant range model is provided, and the numerical slant range history obtained by inversion is compensated in the echo domain and the Doppler domain based on the difference slant range history difference, including: The echo data compensated in the echo domain is compensated in the Doppler domain. After the echo expression of the echo data compensated in the echo domain is focused in the frequency domain, Doppler compensation is performed to obtain a range-Doppler domain analytical expression; Based on the range-Doppler domain analytical expression, a Doppler compensation phase is determined, and inverse Fourier transform in the azimuth direction is performed to complete focusing.

[0014] In the second aspect, a Doppler phase compensation system based on an inversion slant range model is provided, including: A positioning module is configured to position a scene target based on a priori digital elevation model to determine a target point position. An inversion module is configured to invert a numerical slant range history of the target point position based on satellite orbit information. A comparison module is configured to compare the numerical slant range history with an analytical slant range history to obtain a difference slant range history difference; A compensation module is configured to perform Doppler phase compensation on echo domain echoes of the inverted slant range history based on the difference slant range history difference, and complete focusing.

[0015] In a third aspect, the present application further provides an electronic device, which comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the method for Doppler phase compensation based on an inverted slant range model according to any one of the above aspects when executing the program.

[0016] In a fourth aspect, the present application further provides a non-transitory computer readable storage medium, which stores a computer program, and the computer program is executable on a processor to implement the method for Doppler phase compensation based on an inverted slant range model according to any one of the above aspects.

[0017] In a fifth aspect, the present application further provides a computer program product, which comprises a computer program, and the computer program is executable on a processor to implement the method for Doppler phase compensation based on an inverted slant range model according to any one of the above aspects.

[0018] The present application provides a method and system for Doppler phase compensation based on an inverted slant range model, which comprises the following steps: positioning a target in a scene based on a prior digital elevation model to determine a target point position; inverting a numerical slant range history of the target point position based on satellite orbit information; comparing the numerical slant range history with an analytical slant range history to obtain a difference slant range history difference; and performing phase compensation on the inverted numerical slant range history in echo domain and Doppler domain based on the difference slant range history difference to complete focusing. The difference between the numerical slant range history and the analytical slant range history is compensated in echo domain and image Doppler domain respectively, the influence of a large target elevation fluctuation area in an imaging scene is considered, the focusing performance is better, and the problem of focusing performance degradation is effectively solved. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0020] Figure 1 is a flowchart of the method for Doppler phase compensation based on an inverted slant range model provided by the present embodiment; Figure 2 is a simulation comparison diagram of an inverted slant range numerical value and a traditional hyperbolic slant range model provided by the present embodiment; Figure 3is a schematic diagram of the focusing result of the conventional hyperbolic slant range model and the focusing result of the slant range model provided by the present application after azimuthal Doppler phase compensation, provided by the embodiment of the present application; Figure 4 is a detailed imaging diagram of target 2, provided by the embodiment of the present application; Figure 5 is a structural schematic diagram of the Doppler phase compensation system based on the inversion slant range model, provided by the embodiment of the present application; Figure 6 is a structural schematic diagram of the electronic device, provided by the embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0022] Figure 1 is a flow schematic diagram of the Doppler phase compensation method based on the inversion slant range model, provided by the embodiment of the present application.

[0023] As shown in Figure 1 , the Doppler phase compensation method based on the inversion slant range model provided by the embodiment of the present application mainly includes the following steps: 101, positioning a scene target based on a priori digital elevation model to determine a target point position.

[0024] Specifically, the satellite position information, speed information, slant range information and Doppler information corresponding to an imaging time period are input into a positioning equation set, such as formula (1): (1) wherein, is a satellite position, is a target point position, is a slant range vector of a radar to the target point, is a modulus value of the slant range vector, is a speed vector of the radar relative to the target point, is a Doppler center frequency, is an equatorial radius, is a polar radius, is an initial elevation of the target point, and the above equation set can be solved by using Newton iteration to obtain the corresponding initial target point position.

[0025] For sea surface target, the initial height of the initial target point position can be set as 0, but for the target with large height fluctuation in the scene, the initial height of the initial target point position can be corrected by the priori digital elevation model (DEM) through iterative height correction value The more accurate target point position in the scene can be obtained , and the target point position of the target in the WGS84 coordinate system is obtained.

[0026] 102. Numerical slant range history of the target point position is obtained based on satellite orbit information.

[0027] Specifically, for each transmission pulse moment of the SAR and the transmission position and the transmission speed of the radar at this moment, there is a unique pulse reception moment and the reception position and the reception speed of the radar at this moment, through iterative search to satisfy the preset condition based on the target point position, such as (2): (2) where c is the speed of light.

[0028] The specific process of the iterative search is as follows: Based on the closest slant range of the illuminated scene and the speed of light, the initial value is determined , such as (3): (3) wherein is the closest slant range of the illuminated scene, which is a known parameter in the SAR task, and C is the speed of light.

[0029] Based on the initial value and , the arbitrary pulse reception moment is determined, and the corresponding reception position and reception speed and are interpolated, such as (4): (4) The reception position, the reception speed and the target point position are input into the time delay error formula to obtain the time delay error , such as formula (5): (5) The time delay error is compared with the preset iteration threshold value, if the time delay error is less than the corresponding iteration threshold value, the iteration is exited, otherwise the arbitrary pulse reception moment is updated. The above steps are repeated until the time delay error is less than the corresponding iteration threshold.

[0030] According to the results after iteration convergence, the time of each emission pulse The corresponding two-way slant range And the two-way Doppler frequency As (6) and (7): (6) (7) Wherein, The radar wavelength.

[0031] And the Doppler frequency Satisfy one-to-one mapping, so with The numerical slant range history And the mapping relationship between the Doppler frequency .

[0032] 103, The numerical slant range history is compared with the analytical slant range history, and the difference slant range history difference is obtained.

[0033] Figure 2 The simulation results of the numerical slant range history of the target point in the scene and the slant range history of the traditional hyperbolic curve analytical slant range model are shown in FIG. Figure 2 From Figure 2 It can be seen that the calculation results of the two are consistent, and the model difference of the two models is Then (8) is obtained: (8) Wherein, The numerical slant range history obtained by inversion is The obtained by the hyperbolic slant range model is The azimuth time.

[0034] The reason for this difference is that the flight trajectory of the satellite platform is not strictly straight at a constant speed. Therefore, it can be inferred that the slant range history difference between all scattering points in the illuminated scene has a component related only to the satellite orbit and unrelated to the scattering point position, called consistent slant range history difference This value is only related to time, and the difference between the slant range history difference of each scattering point and the consistent slant range history difference is the difference slant range history difference Then (9) is obtained: (9) This difference This is caused by a combination of factors, including the different elevations of the scattering points.

[0035] 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.

[0036] 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): (10) in, For distance to time, To adjust the frequency, The pulse width. For carrier frequency, It is the azimuth angle.

[0037] Will Substituting into equation (10) above, we get (11): (11) 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): (12) Will Substituting into equation (12) above, we get (13): (13) 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): (14) 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): (15) in: (16) 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.

[0038] 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): (17) in, For azimuth bandwidth, The center frequency of the Doppler wave. The zero Doppler moment.

[0039] After compensating for the phase of equation (18), precise focusing can be achieved by performing an inverse Fourier transform of the azimuth.

[0040] (18) 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.

[0041] 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.

[0042] Table 1

[0043] The application constructs a numerical slant range model (depending on satellite orbiting accuracy and DEM accuracy) accurate to sub-centimeter level by combining satellite platform position and velocity information with global prior DEM data, and innovatively decomposes slant range model error into two steps of echo domain phase compensation and image Doppler domain space variant correction. Experimental simulation verification shows that the algorithm has obvious focusing performance improvement in areas with large terrain undulations, and even in flat areas, the focusing is better than that of the traditional algorithm.

[0044] Based on the same overall inventive concept, the application also protects a structure diagram of a Doppler phase compensation system based on an inverse slant range model. The structure diagram of the Doppler phase compensation system based on the inverse slant range model described below can be mutually referred to with the structure diagram of the Doppler phase compensation system based on the inverse slant range model described above.

[0045] Figure 5 The structure diagram of the Doppler phase compensation system based on the inverse slant range model provided by the embodiment.

[0046] As shown in Figure 5 , the Doppler phase compensation system based on the inverse slant range model provided by the embodiment includes: A positioning module 501 is configured to position a scene target based on a prior digital elevation model, and determine a target point position. An inversion module 502 is configured to invert a numerical slant range history of the target point position based on satellite orbit information. A comparison module 503 is configured to compare the numerical slant range history with an analytical slant range history, and obtain a difference slant range history difference. A compensation module 504 is configured to perform Doppler phase compensation on echo in an echo domain of the inverted slant range history based on the difference slant range history difference, and complete focusing.

[0047] Figure 6 The structure diagram of the electronic device provided by the embodiment.

[0048] As shown in Figure 6As shown, the electronic device can include a processor 610, a communications interface 620, a memory 630, and a communications bus 640, wherein the processor 610, the communications interface 620, and the memory 630 complete mutual communication through the communications bus 640. The processor 610 can invoke a logic instruction in the memory 630 to execute a Doppler phase compensation method based on an inversion slant range model, which includes: scene target positioning based on a prior digital elevation model, determining a target point position; inversion of a numerical slant range history of the target point position based on satellite orbit information; comparing the numerical slant range history with an analytical slant range history to obtain a difference slant range history difference; and based on the difference slant range history difference, performing phase compensation in the echo domain and the Doppler domain on the inverted numerical slant range history to complete focusing.

[0049] In addition, the logic instruction in the memory 630 described above can be implemented in the form of a software function unit and sold or used as an independent product, which can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, which is stored in a storage medium, includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various program code storage media.

[0050] On the other hand, the present application also provides a computer program product, which includes a computer program, the computer program can be stored on a non-transitory computer readable storage medium, and the computer program is executed by a processor, and the computer can execute the Doppler phase compensation method based on the inversion slant range model provided by the above-mentioned method, which includes: scene target positioning based on a prior digital elevation model, determining a target point position; inversion of a numerical slant range history of the target point position based on satellite orbit information; comparing the numerical slant range history with an analytical slant range history to obtain a difference slant range history difference; and based on the difference slant range history difference, performing phase compensation in the echo domain and the Doppler domain on the inverted numerical slant range history to complete focusing.

[0051] In yet another aspect, the present application also provides a non-transitory computer readable storage medium having stored thereon a computer program, which, when executed by a processor, implements the method for Doppler phase compensation based on inversion slant range model as provided above, and the method comprises: scene target positioning based on a prior digital elevation model to determine a target point position; inversion of a numerical slant range history of the target point position based on satellite orbit information; comparison of the numerical slant range history with an analytical slant range history to obtain a difference slant range history difference; phase compensation of the inverted numerical slant range history in echo domain and Doppler domain based on the difference slant range history difference to complete focusing.

[0052] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0053] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software plus necessary universal hardware platforms, and of course can also be realized by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part that contributes to the prior art, can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes a number of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0054] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to some technical features; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A Doppler phase compensation method based on an inversion slant range model, characterized in that, The method comprises the following steps: determining the target point position based on the prior digital elevation model; inverting the numerical slant range history of the target point position based on the satellite orbit information; comparing the numerical slant range history with the analytical slant range history to obtain the difference slant range history difference; performing phase compensation in the echo domain and the Doppler domain on the inverted numerical slant range history based on the difference slant range history difference, and completing focusing.

2. The method of claim 1, wherein, The method for determining the target point position based on the prior digital elevation model comprises the following steps: inputting the corresponding satellite position information, velocity information, slant range information and Doppler information in the imaging time period into a positioning equation set; using the prior digital elevation model to solve the target point position of the scene target in the WGS84 coordinate system by iteratively searching the initial elevation of the target point in the positioning equation set.

3. The method of claim 1, wherein, The method for inverting the numerical slant range history of the target point position based on the satellite orbit information comprises the following steps: determining the transmission time, position and velocity of each transmission pulse of the SAR; through iterative search, the transmission time, position and velocity of each transmission pulse and the corresponding pulse reception time, position and velocity satisfy a preset condition based on the target point position; based on the results of the iterative convergence, the two-way slant range and the two-way Doppler frequency corresponding to each transmission pulse time are obtained; based on the two-way slant range and 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 method of claim 3, wherein, The iterative search comprises the following steps: determining an initial value based on the nearest slant range of the illuminated scene and the speed of light; based on the initial value, determining an arbitrary pulse reception time and interpolating the corresponding reception position and reception velocity; inputting the reception position, the reception velocity and the target point position into a time delay error formula to obtain a time delay error; if the time delay error is less than the corresponding iterative threshold, the iteration is exited, otherwise the arbitrary pulse reception time is updated.

5. The method of claim 1, wherein, The method for comparing the numerical slant range history with the analytical slant range history to obtain the difference slant range history difference comprises the following steps: determining the model difference between the numerical slant range history and the slant range history of the hyperbolic analytical slant range model; based on the model difference, determining the consistent slant range history difference of all scattering points; determining the difference between the consistent slant range history difference and the slant range history difference of each scattering point to obtain the difference slant range history difference.

6. The Doppler phase compensation method based on an inversion slant range model according to claim 5, characterized in that, The method for performing phase compensation in the echo domain and the Doppler domain on the inverted numerical slant range history based on the difference slant range history difference comprises the following steps: based on the SAR principle, using the model difference and the difference slant range history difference to perform echo domain phase compensation on the echo domain echo expression of the inverted numerical slant range history; performing phase compensation in the Doppler domain on the echo data after the echo domain phase compensation.

7. The Doppler phase compensation method based on an inversion slant range model according to claim 6, characterized in that, The method for using the model difference and the difference slant range history difference to perform echo domain phase compensation on the echo domain echo expression of the inverted numerical slant range history comprises the following steps: based on the SAR principle, determining the echo domain echo expression based on the inverted slant range history; sequentially inputting the model difference and the difference slant range history difference into the echo domain echo expression to obtain an echo domain phase compensation expression; Based on the echo domain phase compensation expression, a compensation phase in the echo domain is determined.

8. The Doppler phase compensation method based on an inversion slant range model according to claim 7, characterized in that, The echo data after the echo domain phase compensation is subjected to phase compensation in the Doppler domain, including: An echo expression in the Doppler domain of the echo data after the echo domain phase compensation is determined; After frequency domain focusing imaging is performed on the echo expression in the Doppler domain, Doppler compensation is performed to obtain a range-Doppler domain analytical expression; Based on the range-Doppler domain analytical expression, a phase after Doppler compensation is determined, and inverse Fourier transform in the azimuth direction is performed to complete focusing.

9. A Doppler phase compensation system based on an inverse slant range model, characterized by, It includes: A positioning module is configured to position a scene target based on a prior digital elevation model to determine a target point position; An inversion module is configured to invert a numerical slant range history of the target point position based on satellite orbit information; A comparison module is configured to compare the numerical slant range history with an analytical slant range history to obtain a difference slant range history difference; A compensation module is configured to perform Doppler phase compensation on echo in the echo domain of the inverted slant range history based on the difference slant range history difference to complete focusing.

10. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor implements the method of Doppler phase compensation based on the inverted slant range model according to any one of claims 1 to 8 when executing the program.

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