An alternating constraint optimization method for locating interference sources

Abstract

The application discloses an alternating constraint optimization interference source positioning method, which comprises the following steps: determining corresponding interference signals according to echo signals of two channels of a radar, and obtaining amplitude difference accumulations based on the interference signals; constructing and solving an actual azimuth coordinate model of an interference source to obtain actual azimuth coordinates of the interference source; constructing phase differences of two channels of a synthetic aperture radar, combining the interference signals corresponding to the two channels to construct a double-channel cancellation positioning model of phase compensation; taking a slant distance of a scene center of a known imaging area of the synthetic aperture radar as a distance coordinate parameter of the interference source, and obtaining a value of corresponding azimuth coordinate parameters at this time, which forms a hypothetical coordinate point together with the slant distance of the scene center; and based on the principle that the hypothetical coordinate point and the actual coordinate of the interference source are on the same double-slant-distance-difference hyperbolic model, solving the value of the distance coordinate parameter based on the double-slant-distance-difference hyperbolic model, so as to obtain the actual coordinate of the interference source.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radar signal processing, and particularly relates to an alternating constraint optimization method for locating interference sources, which is suitable for locating interference sources of radio frequency interference in synthetic aperture radar echoes. BACKGROUND

[0002] Synthetic aperture radar (SAR) plays a key role in earth observation and has the ability of all-weather and all-day. It has been widely used in topographic mapping and disaster warning fields. However, with the increase in the number of electromagnetic devices, the spectrum environment becomes crowded, resulting in unintentional radio frequency interference (RFI) in the same frequency band. Radio frequency interference brings serious challenges to SAR data acquisition, processing and interpretation, so it is of great significance to investigate and recognize the distribution and change of radio frequency interference signals. In addition, the location of interference sources provides important prior information for interference suppression, for example, the location of interference sources can be used to form nulls in the direction of interference using beamforming.

[0003] Current RFI localization methods based on SAR systems are generally divided into single-channel and multi-channel methods. Single-channel methods usually integrate ascending and descending data to obtain the approximate area of the RFI transmitter. The accuracy of these methods is still limited, and the direction of the RFI source transmitting beam is not considered. The new generation of SAR systems adopts a multi-channel architecture, which supports more spatial information to achieve RFI localization and suppression.

[0004] The paper Adaptive Antenna Pattern Notching of Interference in Synthetic Aperture Radar Data Using Digital Beamforming[J]. Remote Sensing, 2019, 11(11): 1346. DOI:10.3390 / rs11111346 proposes a method for RFI suppression and angle of arrival estimation using digital beamforming. Although this algorithm reduces the impact of echo noise covariance estimation on interference by distance compression, it still assumes that the channel spacing is half a wavelength to avoid angle ambiguity.

[0005] The paper AJoint Azimuth Multichannel Cancellation (JAMC) Antibarrage Jamming Scheme for Spaceborne SAR. IEEE J. Sel. Top. Appl. Earth Obs. Remote. Sens. 15:9913-9926 (2022) uses the interference phase of different channels to locate the interference source and realize the positioning of the interference source, but this method has periodic positioning ambiguity, and the operation complexity is high for actual large-scale SAR data.

[0006] The interference source positioning method based on the multi-channel phase interference system analyzes the phase difference of the interference between different channels, and maps the actual interference source coordinates through the spatial characteristics of the phase difference. Compared with the passive phase difference positioning system, the existence of useful signal components in the active SAR data is not conducive to the positioning of single interference signals, and the channel interval of the general multi-channel SAR system is much larger than half a wavelength, which brings indistinguishable ambiguity to the direction of arrival estimation. The channel cancellation positioning method proposed for the active SAR system also has periodic ambiguity, and for large-scale SAR data, this method also has high operation complexity. SUMMARY

[0007] The purpose of the present application is to provide an alternating constraint optimization interference source positioning method to overcome the problems of high algorithm complexity and low efficiency of existing multi-channel interference source positioning algorithms.

[0008] In order to achieve the above-mentioned task, the technical scheme adopted by the present application is as follows:

[0009] An alternating constraint optimization interference source positioning method comprises:

[0010] Step 1, obtaining the echo signals of two channels of synthetic aperture radar and calculating the frequency spectrum thereof, preliminarily screening the interference signals according to a preset frequency band for pretreatment, and converting the pretreated frequency spectrum to the time domain to obtain interference signals only containing interference components;

[0011] Step 2, determining the amplitude difference cumulative sum of the interference signals of the two channels;

[0012] Step 3, based on the amplitude difference cumulative sum and the equivalent speed of the platform where the synthetic aperture radar is located, constructing and solving an actual azimuth coordinate model of the interference source to obtain the actual azimuth coordinate of the interference source;

[0013] Step 4, constructing the phase difference of the two channels of the synthetic aperture radar with respect to the azimuth slow time, the distance coordinate parameter of the interference source and the azimuth coordinate parameter;

[0014] Step 5, on the basis of the two-channel phase difference, combining the two channels corresponding to the interference signal sub-structure phase compensation dual-channel cancellation positioning model; record the distance to the center of the scene in the SAR imaging area, and the slant range of the scene center is known, and the value of the corresponding azimuth coordinate parameter at this time is obtained, which constitutes an assumed coordinate point with the slant range of the scene center;

[0015] Step 6, using the assumed coordinate point and the actual coordinate of the interference source, based on the principle of double slant difference hyperbolic model, the value of the distance coordinate parameter is solved based on the double slant difference hyperbolic model, and the actual coordinate of the interference source is obtained.

[0016] Further, the pre-processing of the initial screening of the interference signal according to the preset frequency band comprises:

[0017] Let the minimum and maximum values of the azimuth sampling point number corresponding to the preset frequency band be Nr p ,Nr q , then the frequency spectrum X i (f,η) in the range of [Nr p ,Nr q ] is reserved, and the data of the remaining frequency band is set to zero, thereby completing the pre-processing of the frequency spectrum.

[0018] Further, the interference signal only exists in the interference component, which is represented as:

[0019]

[0020] Where c is the speed of light, j is the imaginary unit, θ i (η) is the SAR oblique angle at the azimuth slow time η, a i (θ i (η)) is the product of the transmit antenna pattern of the interference source and the receive antenna pattern of the SAR channel i corresponding to θ i (η), k and f0 are the carrier frequencies of the interference signal I i (τ,η) and the echo signal X i (τ,η), is a unified expression of the interference distance signal, that is, the expression of the interference signal I i (τ,η) changing with the distance fast time τ at time η; R Ji (η) is the slant range from the SAR channel i to the interference source at time η.

[0021] Further, the amplitude difference cumulative sum of the interference signals of the two channels is determined, comprising:

[0022] The interference signals corresponding to the two channels are I1(τ,η) and I2(τ,η); a 1×Nr sequence is obtained by subtracting I1(τ,η) and I2(τ,η) at each azimuth slow time η; a cumulative sum ΔI(η) at each slow time η is obtained by summing the sequence; and Nr is the number of azimuth sampling points.

[0023] Further, the actual azimuth coordinate of the interference source is obtained by constructing and solving an actual azimuth coordinate model of the interference source based on the amplitude difference cumulative sum and the equivalent speed of a platform on which the synthetic aperture radar is located, and the actual azimuth coordinate of the interference source comprises:

[0024] A relationship formula of the azimuth coordinate parameter with respect to the azimuth slow time η and the equivalent speed of a platform on which the synthetic aperture radar is located is constructed: y=V r η, wherein V r is the equivalent speed of the platform on which the SAR is located, and y is the coordinate parameter of the platform on which the SAR is located at each azimuth slow time η; the coordinate parameter y is brought into the expression of the cumulative sum ΔI(η) to obtain ΔI(y);

[0025] The actual azimuth coordinate model of the interference source is constructed and solved by using ΔI(y):

[0026]

[0027] wherein, represents the actual azimuth coordinate of the interference source.

[0028] Further, a two-channel phase difference of the synthetic aperture radar with respect to the azimuth slow time, the distance coordinate parameter of the interference source, and the azimuth coordinate parameter is constructed and expressed as:

[0029]

[0030] wherein, η is the azimuth slow time, R x is the distance coordinate parameter of the interference source, and y J is the azimuth coordinate parameter; d is the interval between the two channels of the SAR, and λ is the wavelength of the radar signal.

[0031] Further, the two-channel cancellation positioning model is expressed as:

[0032] {||ΔΦ(η;R x ,y J )I2(τ,η)-I1(τ,η)||1}

[0033] The value of the azimuth coordinate parameter y is determined by the following method:

[0034]

[0035] Wherein, ||·||1 is the L1 norm; δy represents the first fuzzy threshold, and R0 is the slant range of the scene center.

[0036] Further, the double slant range difference hyperbolic model is represented as:

[0037]

[0038] Wherein, ΔR is the slant range difference hyperbolic model parameter, is the value of the range coordinate parameter;

[0039] The value of the range coordinate parameter is obtained by: The actual range coordinate of the interference source is:

[0040] Further, the step 6 can also be replaced by:

[0041] Solving the phase compensation double-channel cancellation positioning model with the range coordinate parameter R x2 as the variable, that is, x2 , J The value of the range coordinate parameter is obtained by:

[0042]

[0043] Wherein, δx is the second fuzzy threshold;

[0044] The value of the range coordinate parameter obtained by the step is: The actual range coordinate of the interference source is: The average of and is also taken as the actual range coordinate of the interference source Thus, the actual coordinate of the interference source is solved.

[0045] A terminal device, comprising a processor, a memory, and a computer program stored in the memory; when the processor executes the computer program, the alternating constraint optimization interference source positioning method is realized.

[0046] A computer readable storage medium, the medium stores a computer program; when the computer program is executed by a processor, the alternating constraint optimization interference source positioning method is realized.

[0047] Compared with the prior art, the present application has the following technical features:

[0048] ​Compared with the traditional positioning method based on multi-channel interference signal interference phase, the application can overcome the problems of serious positioning ambiguity and large SAR data operation amount of two-dimensional optimization model solving, and utilize the advantages of multiple one-dimensional optimization to realize fast positioning of coordinates. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 The figure is a flowchart of the method of the application;

[0050] Figure 2 The figure is a radar channel echo time-domain graph interfered by one in an embodiment of the application;

[0051] Figure 3 The figure is the result of each pulse accumulation of the two-channel interference signal coherent cancellation and each channel in an embodiment of the application;

[0052] Figure 4 The figure is a channel cancellation result curve with azimuth position change of the compensation phase when the distance direction coordinate is R0 in an embodiment of the application.

[0053] Figure 5 The figure is a channel cancellation result curve with slant range change of the compensation phase under the range constraint when the distance direction coordinate solving result is R0 in an embodiment of the application. DETAILED DESCRIPTION

[0054] Referring to the accompanying Figure 1 , the application provides an alternating constraint optimization interference source positioning method, comprising the following steps:

[0055] Step 1, obtaining the echo signals of two channels of a synthetic aperture radar (SAR) and calculating the frequency spectrum thereof, preliminarily screening the interference signals according to a preset frequency band for pretreatment, and converting the pretreated frequency spectrum to the time domain to obtain interference signals existing only interference components.

[0056] Wherein, the echo signal of channel i (i=1 or 2) of the synthetic aperture radar (SAR) is represented as X i (τ,η), τ is the distance fast time, η is the azimuth slow time, the echo data size is Na×Nr, wherein Na is the distance direction sampling point number, and Nr is the azimuth direction sampling point number;

[0057] Let the actual coordinates of the interference source be Wherein is the actual azimuth direction coordinate of the interference source, is the actual distance direction coordinate; the echo signal X i (τ,η) is transformed to the frequency domain along the distance direction to obtain the frequency spectrum X i ​(f, η), where f represents the distance frequency; preliminarily screening the interference signal to be positioned according to a preset frequency band; recording the minimum and maximum values of the azimuth sampling point number corresponding to the preset frequency band as Nr p ,Nr q , then the spectrum spectrum X i (f, η) in the range of [Nr p ,Nr q ] is reserved, and the data of the remaining frequency bands are set to zero, thereby completing the preprocessing of the spectrum; and the preprocessing of the spectrum is represented as: and wherein represents the frequency band corresponding to the first azimuth sampling point to the Nr p th azimuth sampling point, represents the frequency band corresponding to the (Nr q + 1)th azimuth sampling point to the Nrth azimuth sampling point.

[0058] The spectrum X i (f, η) of the channel i of the SAR after preprocessing is inversely transformed back to the time domain to obtain a time domain signal with a higher jamming-to-signal ratio, which is denoted as an interference signal I i (τ, η):

[0059]

[0060] wherein c is the speed of light, j is an imaginary unit, θ i (η) is the SAR squint angle at the azimuth slow time η, a i (θ i (η)) is the product of the transmit antenna pattern of the interference source corresponding to θi(η) and the receive antenna pattern of the channel i of the SAR, f k and f0 are the carrier frequencies of the interference signal I i (τ, η) and the echo signal X i (τ, η), respectively, is a unified expression of the interference distance direction signal, that is, the expression of the interference signal I i (τ, η) changing with the distance fast time τ at the time η; R Ji (η) is the slant range of the channel i of the SAR to the interference source at the time η.

[0061] Step 2, determining the amplitude difference cumulative sum of the interference signals of the two channels.

[0062] The amplitude difference cumulative sum of the interference signals corresponding to two channels of the synthetic aperture radar at each azimuth slow time η is calculated. The interference signals corresponding to two channels (i=1 or 2) are I1(τ,η) and I2(τ,η) respectively. That is, after I1(τ,η) and I2(τ,η) are subtracted at each azimuth slow time η, a 1×Nr sequence is obtained. The cumulative sum ΔI(η) at each slow time η is obtained after the sequence is summed, and is represented as follows:

[0063]

[0064] The cumulative sum at each η forms a 1×Na sequence ΔI, which is a function curve about η.

[0065] In step 3, based on the amplitude difference cumulative sum and the equivalent speed of the platform where the synthetic aperture radar is located, a model of the actual azimuth coordinate of the interference source is constructed and solved to obtain the actual azimuth coordinate of the interference source.

[0066] The relationship between the azimuth coordinate parameter and the azimuth slow time η and the equivalent speed of the platform where the synthetic aperture radar is located is constructed: y=V r η, where V r is the equivalent speed of the platform where the SAR is located, and y is the coordinate parameter of the platform where the SAR is located at each azimuth slow time η. The coordinate parameter y is brought into the expression of the cumulative sum ΔI(η) to obtain ΔI(y). The horizontal axis of ΔI(y) is changed from η to y, and the function value remains unchanged, which is still the result of step 2.

[0067] The model of the actual azimuth coordinate of the interference source is constructed and solved using ΔI(y):

[0068]

[0069] That is, the elements of the direct sorting curve ΔI(y) are sorted to obtain the horizontal axis value corresponding to the minimum value, which is the actual azimuth coordinate of the interference source.

[0070] The principle of this step is that when the position of the platform where the SAR is located is close to the azimuth position of the interference source , the difference in slant range of the interference source to two channels gradually decreases, and the phase difference of the exponential term in formula (1) also gradually decreases. When the position of the platform where the SAR is located is at the azimuth position of the interference source , R J1 (η)≈R J2 (η), and the phase difference of the exponential term in formula (1) is 0. The amplitude difference cumulative sum of the data subtracted by two channels reaches the minimum value.

[0071] In step 4, a relationship about the azimuth slow time η, the distance coordinate parameter R x of the interference source, and the azimuth coordinate parameter y of the interference source is constructed.J two-channel phase difference of synthetic aperture radar ΔΦ(η;R x ,y J ):

[0072]

[0073] where d is the two-channel interval of the SAR, and λ is the wavelength of the radar signal.

[0074] Step 5, based on the two-channel phase difference of the synthetic aperture radar, a phase compensation two-channel cancellation positioning model is constructed by combining the corresponding interference signal components of the two channels: {||ΔΦ(η;R x ,y J )I2(τ,η)-I1(τ,η)||1}; and the distance coordinate parameter R x of the interference source is taken as the slant range R0of the scene center of the known synthetic aperture radar imaging area (the closest slant range from the platform of the SAR to the scene center), the value of the azimuth coordinate parameter of the interference source is solved when the distance coordinate parameter R x of the scene center is R0 and the value of the azimuth coordinate parameter of the interference source is solved when the distance coordinate parameter R of the scene center is R0

[0075]

[0076] where ||·||1 is the L1 norm, and δy represents the first blur threshold, which can be set according to experience or calculated according to the blur period formula .

[0077] This step adopts the phase compensation two-channel cancellation positioning model: {||ΔΦ(η;R x ,y J )I2(τ,η)-I1(τ,η)||1}, and when the optimal solution y J is determined, the constructed ΔΦ(η;R0,y J ) exactly compensates for the phase difference between I1(τ,η) and I2(τ,η), so that the residual value of I2(τ,η) after compensation and subtraction of I1(τ,η) is minimized.

[0078] This two-channel cancellation positioning model reduces a two-dimensional search to a one-dimensional search, which can be directly solved in a one-dimensional search manner or solved in a numerical iteration manner with better efficiency. The principle of this step is based on the hyperbolic model introduced in Step 6, the horizontal axis of the hyperbolic curve is the distance coordinate axis, and the vertical axis is the azimuth coordinate axis. All points on the curve correspond to the spatial coordinates, which can make {||ΔΦ(η;R x ,y J ​)I2(τ,η)-I1(τ,η)||1} takes the minimum value; therefore, as long as the point on the line is determined by formula (5) The model parameters of the hyperbola can be determined, so that the azimuth coordinates of the real interference source solved in step 3 can be converted to After substituting the hyperbolic expression, the actual distance coordinate of the interference source can be solved See step 6 for the specific solution method.

[0079] Step 6, since the coordinate point is assumed and the actual coordinates of the interference source All on the same double slope range difference hyperbola model, according to the azimuth coordinate values ​​obtained Calculate the slope range difference hyperbola model parameter ΔR; solve the value of the range coordinate parameter based on the model

[0080] Substitute the coordinate points into the following formula The actual azimuth coordinates of the interference source obtained in step 3 Solve the value of the interference source distance coordinate parameter

[0081]

[0082] Add the distance to the value of the coordinate parameter The actual distance to the interference source Thus, the actual coordinates of the interference source are completed Alternatively, this solution can replace step 6 with:

[0083] Step 7: To further improve the accuracy of the range coordinate solution, this step is to calculate the actual azimuth coordinates of the interference source. Based on this, solve the distance coordinate parameter R x2 The phase compensation dual-channel cancellation positioning model with variables {||ΔΦ(η;R x2 ,y J )I2(τ,η)-I1(τ,η)||1}, find the value of the distance coordinate parameter The solution range is limited to step 6 to find and the second fuzzy threshold δx.

[0084]

[0085] The second fuzzy threshold δx can be set based on experience or calculated based on the fuzzy period formula: Sure.

[0086] The value of the distance coordinate parameter solved in this step Actual distance coordinates that can be used as interference sources can also be and The average is taken as the actual distance coordinate of the interference source Thus, the actual coordinates of the interference source are completed The model can be solved directly by one-dimensional search, or by numerical iteration for better solution efficiency.

[0087] This step is not calculated by the hyperbolic model, but uses the phase compensation dual-channel cancellation positioning model {||ΔΦ(η;R x2 ,y J )I2(τ,η)-I1(τ,η)||1}, when determining R x is the optimal solution, that is, the true distance coordinate When the constructed ΔΦ(η;R x2 ,y J ) exactly compensates for the phase difference between I1(τ,η) and I2(τ,η), minimizing the residual value after I2(τ,η) compensates for the phase difference and subtracts it from I1(τ,η). The range coordinates calculated in this way can further verify the range coordinates calculated based on the hyperbolic model in step 6. The fusion of these two calculation results can also make the positioning result more accurate.

[0088] Example:

[0089] In one embodiment of the present invention, Figure 2 Figure 1 shows the channel 1 time domain echo signal X1(τ,η) with linear frequency modulation interference superimposed on pulses 3004 to 4915. The interference source is located at 754.43 km in range and -1000 m in azimuth, with the center of the scene as the origin. The interference source is located within the survey swath. Figure 3 The blue line in the middle represents the ΔI(η) of the data of this embodiment, which shows a trend of first decreasing and then increasing. The horizontal axis is substituted with the actual azimuth coordinate. The minimum value of ΔI(η) of the blue curve corresponds to the actual azimuth coordinate of -1008.855m, with a deviation of 8.855m.

[0090] Figure 4 is the result of two-channel cancellation after phase compensation. In this embodiment, the value of SAR system R0 is 764.53 km, and the solution is The corresponding curve minimum orientation position is -1025.43m; The value is 759.04km, which deviates from the true position by 4.51km, and the positioning error is 4.51km.

[0091] like Figure 5 As shown, the The value of the distance vector is 758.85 km, the distance vector deviation from the real position is 4.31 km, and the positioning error is 4.31 km.

[0092] The above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. An alternating constrained optimization interference source location method, characterized in that: include: Step 1: Acquire the echo signals of the two channels of the synthetic aperture radar and calculate their spectra. Pre-process the interference signals according to the preset frequency band and convert the pre-processed spectra into the time domain to obtain the interference signal with only the interference component. Step 2: Determine the cumulative sum of the amplitude differences of the interference signals of the two channels; Step 3: Based on the accumulated amplitude difference and the equivalent velocity of the platform where the synthetic aperture radar is located, a model of the actual azimuth coordinate of the interference source is constructed and solved to obtain the actual azimuth coordinate of the interference source; Step 4: construct the two-channel phase difference of the synthetic aperture radar with respect to the azimuth slow time, the range coordinate parameters of the interference source, and the azimuth coordinate parameters; Step 5: Based on the phase difference between the two channels, a dual-channel cancellation positioning model with phase compensation is constructed in combination with the interference signals corresponding to the two channels; the range coordinate parameter of the interference source is recorded as the known slant distance of the scene center of the synthetic aperture radar imaging area, and the corresponding azimuth coordinate parameter value is obtained at this time. This value and the slant distance of the scene center constitute a hypothetical coordinate point; Step 6: Using the principle that the assumed coordinate point and the actual coordinates of the interference source are both in the same dual slope-range difference hyperbola model, the values ​​of the range coordinate parameters are solved based on the dual slope-range difference hyperbola model to obtain the actual coordinates of the interference source.

2. The method for locating interference sources by alternating constraint optimization according to claim 1, characterized in that: The pre-processing of initially screening the interference signal according to the preset frequency band includes: The minimum and maximum number of sampling points in the azimuth direction corresponding to the preset frequency band are recorded as Nr p ,Nr q , then the spectrum X i (f,η) corresponds to [Nr p ,Nr q ] range frequency band data is retained, and the data of the remaining frequency bands are set to zero, thereby completing the spectrum preprocessing process, f represents the range frequency, and η is the azimuth slow time.

3. The method for locating interference sources by alternating constraint optimization according to claim 1, characterized in that: The interference signal with only interference components is expressed as: Where c is the speed of light, j is the imaginary unit, θ i (η) is the SAR slant angle under the azimuth slow time η, a i (θ i (η)) is θ i (η) corresponds to the product of the transmit antenna pattern of the interference source and the receive antenna pattern of SAR channel i, f k and f0 are the interference signal I i (τ,η) and the echo signal X i The carrier frequency of (τ,η), The unified expression of interference distance signal is: interference signal I i The expression of (τ,η) changing with the distance time τ at time η; R Ji (η) is the slant range from SAR channel i to the interference source at time η.

4. The method for locating interference sources by alternating constraint optimization according to claim 1, characterized in that: Determine the cumulative sum of the amplitude difference between the interference signals of the two channels, including: The interference signals corresponding to the two channels are I1(τ,η) and I2(τ,η), respectively. After subtracting I1(τ,η) and I2(τ,η) at each azimuth slow time η, a 1×Nr sequence is obtained. The cumulative sum ΔI(η) at each azimuth slow time η is obtained by summing the sequence. Nr is the number of azimuth sampling points, and τ is the range fast time.

5. The method for locating interference sources by alternating constraint optimization according to claim 4, characterized in that: The method of constructing and solving the actual azimuth coordinate model of the interference source based on the accumulated amplitude difference and the equivalent speed of the platform on which the synthetic aperture radar is located to obtain the actual azimuth coordinate of the interference source includes: Construct the relationship between the azimuth coordinate parameters and the azimuth slow time η and the equivalent velocity of the synthetic aperture radar platform: y = V r η, where V r is the equivalent velocity of the SAR platform, and y is the coordinate parameter of the SAR platform at each azimuth slow time η; the coordinate parameter y is substituted as η into the expression of the cumulative sum ΔI(η) to obtain ΔI(y); Use ΔI(y) to construct and solve the actual azimuth coordinate model of the interference source: in, Indicates the actual azimuth coordinates of the interference source.

6. The method for locating interference sources by alternating constraint optimization according to claim 1, characterized in that: The two-channel phase difference of the synthetic aperture radar constructed with respect to the azimuth slow time, the range coordinate parameters of the interference source, and the azimuth coordinate parameters is expressed as: Where η is the azimuth slow time, j is the imaginary unit, V r is the equivalent speed of the platform where the SAR is located, R x is the distance coordinate parameter of the interference source, y J is the azimuth coordinate parameter; d is the interval between the two channels of SAR, and λ is the wavelength of the radar signal.

7. The method for locating interference sources by alternating constraint optimization according to claim 1, characterized in that: The dual-channel cancellation positioning model is expressed as: {||ΔΦ(η;R x ,y J )I2(τ,η)-I1(τ,η)||1} Where, ΔΦ(η; R x ,y J ) represents the phase difference between the two channels of synthetic aperture radar, I1(τ,η) and I2(τ,η) are the interference signals corresponding to the two channels; R x is the distance coordinate parameter of the interference source, y J is the azimuth coordinate parameter, η is the azimuth slow time, τ is the distance fast time, and ||·||1 is used to find the L1 norm; The value of the azimuth coordinate parameter The method to determine is: Where R0 is the slant distance from the center of the scene, δy represents the first blur threshold, is the actual azimuth coordinate of the interference source, and R0 is the slant distance from the center of the scene.

8. The method for locating interference sources by alternating constraint optimization according to claim 1, characterized in that: The dual slope difference hyperbola model is expressed as: Among them, R0 is the slant distance from the center of the scene, R x is the distance coordinate parameter of the interference source, is the value of the azimuth coordinate parameter, d is the interval between the two channels of SAR, ΔR is the slant range difference hyperbolic model parameter, is the actual azimuth coordinate of the interference source, y is the coordinate parameter of the SAR platform at each azimuth slow time η, is the value of the distance coordinate parameter; Add the distance to the value of the coordinate parameter The actual distance to the interference source 9. The method for locating interference sources by alternating constraint optimization according to claim 1, characterized in that: The step 6 can also be replaced by: Solve the distance coordinate parameter R x2 The phase compensation dual-channel cancellation positioning model with variables {||ΔΦ(η;R x2 ,y J )I2(τ,η)-I1(τ,η)||1}, find the value of the distance coordinate parameter Where, ΔΦ(η; R x2 ,y J ) represents the distance coordinate parameter R x2 is the phase difference between the two channels of the variable synthetic aperture radar, I1(τ,η) and I2(τ,η) are the interference signals corresponding to the two channels; J is the azimuth coordinate parameter, η is the azimuth slow time, τ is the distance fast time, ||·||1 is the L1 norm, R x is the distance coordinate parameter of the interference source, is the value of the range coordinate parameter, δx is the second fuzzy threshold; The value of the distance coordinate parameter solved in this step The actual distance to the interference source Or and The average is taken as the actual distance coordinate of the interference source Thus, the actual coordinates of the interference source are completed The solution.

10. A terminal device comprising a processor, a memory, and a computer program stored in the memory; characterized in that: When the processor executes the computer program, the alternating constraint optimization interference source positioning method according to any one of claims 1 to 9 is implemented.

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