Alternating constraint optimization interference source positioning method

Abstract

The invention discloses an alternating constraint optimization interference source positioning method, which comprises the steps of determining a corresponding interference signal according to echo signals of two channels of a radar, obtaining an amplitude difference cumulative sum based on the interference signal, constructing and solving an actual azimuth coordinate model of an interference source, and obtaining actual azimuth coordinates of the interference source; a phase difference of two channels of the synthetic aperture radar is constructed, and a phase-compensated dual-channel cancellation positioning model is constructed by combining interference signals corresponding to the two channels; recording distance coordinate parameters of an interference source, taking a known scene center slant distance of an imaging area of the synthetic aperture radar, solving a value of a corresponding azimuth coordinate parameter at the moment, and forming a hypothetical coordinate point by the value and the scene center slant distance; based on the principle that the assumed coordinate points and the actual coordinates of the interference source are in the same double-slant-distance-difference hyperbolic model, the value of the distance coordinate parameters is solved on the basis of the double-slant-distance-difference hyperbolic model, and therefore the actual coordinates of the interference source are obtained.

Description

Technical Field

[0001] The present invention relates to the field of radar signal processing, and particularly to an alternating constraint optimization interference source localization method, which is applicable to the interference source localization of radio frequency interference in synthetic aperture radar echoes. Background Art

[0002] Synthetic Aperture Radar (SAR) plays a key role in Earth observation and has the capabilities of all-weather and all-time. It has been widely used in fields such as topographic mapping and disaster warning. 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 poses severe challenges to SAR data acquisition, processing, and interpretation. Therefore, it is of great significance to investigate and understand the distribution and variation of radio frequency interference signals. In addition, interference source localization provides important prior information for interference suppression. For example, the position of the interference source can be used to form a null in the interference direction using beamforming.

[0003] Currently, RFI localization methods based on SAR systems are generally divided into single-channel and multi-channel methods. Single-channel methods usually synthesize ascending and descending orbit 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 emission beam is not considered. The new generation of SAR systems adopts a multi-channel architecture, supporting 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" proposed a method for RFI suppression and angle of arrival estimation using digital beamforming. Although this algorithm reduces the influence of echoes on the interference noise covariance estimation through range compression, it still assumes that the channel spacing is half a wavelength to avoid angle ambiguity.

[0005] The paper "A Joint 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-channel RFIs to locate the interference sources and achieve interference source localization. However, such methods have periodic localization ambiguities and high computational complexities for actual large-scale SAR data.

[0006] The interference source localization method based on the multi-channel phase interference system analyzes the phase difference of interference between different channels and maps the actual interference source coordinates through the spatial characteristics of this phase difference. Compared with the passive phase difference localization system, the useful signal components in the active SAR data are not conducive to the localization of a single interference signal, and generally, the channel spacing of multi-channel SAR systems is much larger than half a wavelength, which brings indistinguishable ambiguities to the estimation of the direction of arrival angle. The channel cancellation localization proposed for the active SAR system will also produce periodic ambiguities. For large-scale SAR data, such methods also have high computational complexities. Summary of the Invention

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

[0008] To achieve the above tasks, the present invention adopts the following technical solutions:

[0009] An alternating constraint optimization interference source localization method, including:

[0010] Step 1, obtain the echo signals of two channels of a synthetic aperture radar and calculate their spectra, perform preprocessing on the interference signals by initially screening according to a preset frequency band, and convert the preprocessed spectra into the time domain to obtain interference signals that only contain interference components;

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

[0012] Step 3, based on the cumulative sum of the amplitude differences and the equivalent velocity of the platform where the synthetic aperture radar is located, construct and solve the actual azimuth coordinate model of the interference source to obtain the actual azimuth coordinate of the interference source;

[0013] Step 4, construct the phase difference of the two channels of the synthetic aperture radar regarding the azimuth slow time, the range coordinate parameters of the interference source, and the azimuth coordinate parameters;

[0014] Step 5: Based on the phase difference between the two channels, a dual-channel cancellation and positioning model with phase compensation is constructed by combining the interference signals corresponding to the two channels; record that the range coordinate parameter of the interference source takes the slant range of the scene center of the known synthetic aperture radar imaging area, and obtain the value of the corresponding azimuth coordinate parameter at this time. This value and the slant range of the scene center form a hypothetical coordinate point;

[0015] Step 6: Using the principle that both the coordinates of the hypothetical coordinate point and the actual coordinates of the interference source are on the same double slant range difference hyperbola model, solve for the value of the range coordinate parameter based on the double slant range difference hyperbola model, so as to obtain the actual coordinates of the interference source.

[0016] Further, the preprocessing of initially screening the interference signal according to the preset frequency band includes:

[0017] Record the minimum and maximum values of the number of azimuth sampling points corresponding to the preset frequency band as Nr p ,Nr q , then retain the data in the frequency band range corresponding to [Nr i (f,η) and set the data in the remaining frequency bands to zero, thus completing the preprocessing process of the frequency spectrum. p ,Nr q in the frequency spectrum X

[0018] Further, the interference signal with only interference components is expressed as:

[0019]

[0020] where c is the speed of light, j is the imaginary unit, θ i (η) is the SAR squint angle at azimuth slow time η, a i (θ i (η)) is the product of the transmitting antenna pattern of the interference source corresponding to θ i (η) and the receiving antenna pattern of SAR channel i, f k and f 0 are the carrier frequencies of the interference signal I i (τ,η) and the echo signal X i (τ,η) respectively, is the unified expression of the interference range signal, that is, the expression of the interference signal I i (τ,η) varying with the range fast time τ at time η; R Ji (η) is the slant range from SAR channel i to the interference source at time η.

[0021] Further, determining the cumulative sum of the amplitude differences of the interference signals in the two channels includes:

[0022] The interference signals corresponding to the two channels are I 1 (τ,η), I2 (τ, η); Subtract I 1 (τ, η) and I 2 After subtracting (τ, η) at each azimuth slow time η, a 1×Nr sequence is obtained; after summing this sequence, the cumulative sum ΔI(η) at each slow time η is obtained; Nr is the number of sampling points in the azimuth direction.

[0023] Furthermore, based on the cumulative sum of the amplitude differences and the equivalent velocity of the platform where the synthetic aperture radar is located, construct and solve the actual azimuth coordinate model of the interference source to obtain the actual azimuth coordinates of the interference source, including:

[0024] Construct a relationship between the azimuth coordinate parameter, the azimuth slow time η, and the equivalent velocity of the platform where the synthetic aperture radar is located: y = V r η, where V r is the equivalent velocity 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; Substitute the coordinate parameter y as η into the expression of the cumulative sum ΔI(η) to obtain ΔI(y);

[0025] Use ΔI(y) to construct and solve the actual azimuth coordinate model of the interference source:

[0026]

[0027] where, represents the actual azimuth coordinates of the interference source.

[0028] Furthermore, construct the phase difference between the two channels of the synthetic aperture radar with respect to the azimuth slow time, the range coordinate parameter of the interference source, and the azimuth coordinate parameter, expressed as:

[0029]

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

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

[0032] {||ΔΦ(η; R x , y J )I 2 (τ, η) - I 1 (τ, η)|| 1}

[0033] The method for determining the value of the azimuth coordinate parameter is as follows:

[0034]

[0035] where, ||·|| 1 is for calculating the L1 norm; δy represents the first fuzzy threshold, and R 0 is the slant range of the scene center.

[0036] Furthermore, the double slant range difference hyperbola model is expressed as:

[0037]

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

[0039] Taking the value of the range coordinate parameter as the actual range coordinate of the interference source

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

[0041] Solving the phase compensation two-channel cancellation positioning model {||ΔΦ(η; R x2 , y x2 , y J )I 2 (τ, η) - I 1 (τ, η)|| 1} with the range coordinate parameter R as the variable, and obtaining the value of the range coordinate parameter

[0042]

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

[0044] The value of the range coordinate parameter obtained by this step can be used as the actual range coordinate of the interference source It can also be and Taking the average as the actual range coordinate of the interference source Thus, the solution of the actual coordinates of the interference source is completed.

[0045] A terminal device includes 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 implemented.

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

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

[0048] Compared with the traditional positioning method based on the interference phase of multi-channel interference signals, the present invention can overcome the problems of serious positioning ambiguity and large computational workload of the two-dimensional optimization model for SAR large-scale data, and utilize the advantages of alternating constraints optimization of multiple one-dimensional optimizations to achieve fast positioning of coordinates. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic flow chart of the method of the present invention;

[0050] Figure 2 is the time-domain diagram of the echo of radar channel 1 disturbed in an embodiment of the present invention;

[0051] Figure 3 is the result of the sum of each pulse accumulation of each channel after the coherent cancellation of the two-channel interference signal in an embodiment of the present invention;

[0052] Figure 4 In an embodiment of the present invention, it is assumed that the range coordinate is R 0 The curve of the cancellation result of the compensated phase with the azimuth position change when.

[0053] Figure 5 is the solution result of the range coordinate in an embodiment of the present invention Under the range constraint, the curve of the cancellation result of the compensated phase with the slant range change. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] Referring to the attached Figure 1 , the present invention provides an alternating constraint optimization interference source positioning method, including the following steps:

[0055] Step 1, obtain the echo signals of two channels of a synthetic aperture radar and calculate their spectra, perform preprocessing on the interference signals by preliminary screening according to a preset frequency band, and convert the preprocessed spectra into the time domain to obtain interference signals with only interference components.

[0056] Among them, the echo signal of channel i (i = 1 or 2) of the synthetic aperture radar (SAR) is expressed as X i (τ, η), where τ is the fast time in the range direction and η is the slow time in the azimuth direction. The size of the echo data is Na×Nr, where Na is the number of sampling points in the range direction and Nr is the number of sampling points in the azimuth direction;

[0057] Denote the actual coordinates of the interference source as Among them is the actual azimuth coordinate of the interference source, is the actual range coordinate; transform the echo signal X i (τ, η) into the frequency domain along the range direction to obtain the spectrum Xi (f, η), where f represents the range frequency; preliminarily screen the interference signal to be located according to the preset frequency band; denote the minimum and maximum values of the number of azimuth sampling points corresponding to the preset frequency band as Nr p , Nr q , then the spectrum X i (f, η) corresponding to the range [Nr p , Nr q retains the range band data, and sets the data of the remaining frequency bands to zero, thereby completing the preprocessing process of the spectrum; expressed as: and where 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 th azimuth sampling point to the Nrth azimuth sampling point.

[0058] Inverse transform the spectrum X i (f, η) of the i-th channel of the SAR back to the time domain to obtain a time domain signal with a higher interference-to-signal ratio. This time domain signal only contains interference components, denoted as the interference signal I i (τ, η):

[0059]

[0060] where c is the speed of light, j is the 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 transmitting antenna pattern of the interference source corresponding to θi(η) and the receiving antenna pattern of the i-th channel of the SAR, f k and f 0 are respectively the carrier frequencies of the interference signal I i (τ, η) and the echo signal X i (τ, η), is the unified expression of the interference range signal, that is, the expression of the interference signal I i (τ, η) varying with the range fast time τ at the η moment; R Ji (η) is the slant range from the i-th channel of the SAR to the interference source at the η moment.

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

[0062] Calculate the cumulative sum of the amplitude differences of the interference signals corresponding to the two channels of the synthetic aperture radar at each azimuth slow time η. Among them, the interference signals corresponding to the two channels (i = 1 or 2) are respectively I 1 (τ, η), I 2(τ, η); that is, I 1 (τ, η), I 2 After subtracting (τ, η) at each azimuth slow time η, a 1×Nr sequence is obtained; after summing this sequence, the cumulative sum ΔI(η) at each slow time η is obtained, which is expressed as follows:

[0063]

[0064] The cumulative sum at each η forms a 1×Na sequence ΔI, which is a history curve with respect to η.

[0065] Step 3: Based on the cumulative sum of the amplitude difference and the equivalent velocity of the platform where the synthetic aperture radar is located, construct and solve the actual azimuth coordinate model of the interference source to obtain the actual azimuth coordinate of the interference source.

[0066] Construct a relational expression for the azimuth coordinate parameter with respect to the azimuth slow time η and the equivalent velocity of the platform where the synthetic aperture radar is located: y = V r η, where V r is the equivalent velocity 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; substitute the coordinate parameter y as η into the expression of the cumulative sum ΔI(η) to obtain ΔI(y); the horizontal axis of ΔI(y) changes from η to y relative to ΔI(η), and the corresponding function value remains unchanged, which is still the result obtained in Step 2.

[0067] Use ΔI(y) to construct and solve the actual azimuth coordinate model of the interference source:

[0068]

[0069] That is, directly sort the elements of the curve ΔI(y), and the obtained horizontal axis value corresponding to the minimum value 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 slant range difference between the interference source and the two channels gradually decreases, and the phase difference of the exponential term in formula (1) also gradually decreases. When the position of the SAR platform is exactly at the azimuth position of the interference source then R J1 (η)≈R J2 (η), the phase difference of the exponential term in formula (1) is 0, and the cumulative sum of the amplitude difference of the subtraction of the two-channel data reaches the minimum value of this curve.

[0071] Step 4: Construct the phase difference ΔΦ(η; R x of the two channels of the synthetic aperture radar with respect to the azimuth slow time η, the range coordinate parameter R J of the interference source, and the azimuth coordinate parameter y x , yJ ):

[0072]

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

[0074] Step 5, based on the phase difference between the two channels of the synthetic aperture radar, construct a two-channel cancellation and positioning model for phase compensation by combining the interference signals corresponding to the two channels {||ΔΦ(η; R x , y J )I 2 (τ, η) - I 1 (τ, η)|| 1}; Denote the range coordinate parameter of the interference source as R x Take the slant range R 0 (the closest slant range from the platform where the SAR is located to the scene center) of the known synthetic aperture radar imaging area, and solve the assumed range coordinate parameter R x of the interference source when it is the slant range R 0 of the scene center and use the value of the azimuth coordinate parameter and the slant range R 0 to construct a hypothetical coordinate point

[0075]

[0076] Among them, ||·|| 1 is to find the L1 norm; δy represents the first ambiguity threshold, which can be set according to experience or calculated according to the ambiguity period calculation formula to determine.

[0077] This step uses the two-channel cancellation and positioning model for phase compensation {||ΔΦ(η; R x , y J )I 2 (τ, η) - I 1 (τ, η)|| 1}, when the optimal solution of y J is optimized to be , the constructed ΔΦ(η; R 0 , y J ) exactly compensates for the phase difference between I 1 (τ, η) and I 2 (τ, η), so that the residual value after subtracting I 2 (τ, η) from I 1 (τ, η) after compensating this phase is minimized.

[0078] This dual-channel cancellation positioning model reduces a two-dimensional search to a one-dimensional search, which can be solved directly by one-dimensional search or more efficiently by numerical iteration. The principle of this step is based on the hyperbola model introduced in Step 6. The horizontal axis of the hyperbola is the distance axis of space, and the vertical axis is the azimuth axis. The spatial coordinates corresponding to all points on the curve can make {||ΔΦ(η; R x ,y J )I 2 (τ,η)-I 1 (τ,η)|| 1} take the minimum value; therefore, as long as a point on the line is determined by formula (5), the model parameters of this hyperbola can be determined, and then the true azimuth coordinate of the interference source solved in Step 3 is substituted into the hyperbola expression, and the actual distance coordinate of the interference source can be solved. See Step 6 for the specific solution method.

[0079] Step 6: Since it is assumed that the coordinate point and the actual coordinate of the interference source are both on the same double slant-range difference hyperbola model, calculate the slant-range difference hyperbola model parameter ΔR based on the obtained azimuth coordinate value ; solve the value of the distance coordinate parameter

[0080] by substituting the following coordinate point and the actual azimuth coordinate of the interference source obtained in Step 3 ; solve the value of the distance coordinate parameter of the interference source

[0081]

[0082] Take the value of the distance coordinate parameter as the actual distance coordinate of the interference source Thus, the solution of the actual coordinate of the interference source is completed; alternatively, this solution can also replace Step 6 with:

[0083] Step 7: To further improve the accuracy of the distance coordinate solution, this step solves the phase compensation dual-channel cancellation positioning model {||ΔΦ(η; R with the distance coordinate parameter R x2 as a variable, and finds the value of the distance coordinate parameter x2 ,y J )I 2 (τ,η)-I 1 (τ,η)|| 1}, and finds the value of the distance coordinate parameter The solution range is limited to the value obtained in Step 6 and determined by the second fuzzy threshold δx.

[0084]

[0085] Among them, the second fuzzy threshold δx can be set according to experience or calculated according to the fuzzy period calculation formula to determine.

[0086] The value of the range coordinate parameter solved in this step can be used as the actual range coordinate of the interference source It can also be and take the average as the actual range coordinate of the interference source Thus, the solution of the actual coordinates of the interference source is completed The model can be solved directly by one-dimensional search or more efficiently by numerical iteration.

[0087] This step does not calculate through the hyperbola model, but adopts the phase compensation two-channel cancellation positioning model {||ΔΦ(η; R x2 , y J ) I 2 (τ, η) - I 1 (τ, η) || 1}}, when it is determined that R x is the optimal solution, that is, the true range coordinate , the constructed ΔΦ(η; R x2 , y J ) exactly compensates for the phase difference between I 1 (τ, η) and I 2 (τ, η), so that after I 2 (τ, η) compensates for this phase, the residual value after subtracting it from I 1 (τ, η) is the smallest. The range coordinate calculated in this way can further verify the range coordinate calculated in Step 6 based on the hyperbola model, and the fusion of the two calculation results can also make the positioning result more accurate.

[0088] Embodiment:

[0089] In an embodiment of the present invention, as Figure 2 shown, for the time-domain echo signal X 1 (τ, η) of Channel 1 with a linear frequency modulation interference superimposed on pulses from 3004 to 4915. Among them, the position of the interference source is set at 754.43 km in the range direction, and in the azimuth direction, with the center position of the scene as the origin, it is set at -1000 m. The interference source is located within the mapping strip. Figure 3The blue line represents ΔI(η) of the data of this embodiment, showing a trend of first decreasing and then increasing; the actual azimuth coordinate is substituted into the horizontal axis, and the minimum value of ΔI(η) of the blue curve corresponds to the index where the true azimuth coordinate is -1008.855 m, with a deviation of 8.855 m.

[0090] Figure 4 It is the cancellation result of two channels after phase compensation. In this embodiment, the value of R substituted into the SAR system 0 is 764.53 km, and the azimuth position corresponding to the minimum value of the corresponding curve is -1025.43 m; it is obtained that the value is 759.04 km, the deviation of this value from the true position is 4.51 km, and the positioning error is 4.51 km.

[0091] As Figure 5 shown, the value obtained in this embodiment is 758.85 km, the deviation in the range direction from the true position is 4.31 km, and the positioning error is 4.31 km.

[0092] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; 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 all be included within the protection scope of the present application.

Claims

1. An alternating constrained optimization interference source location method, characterized in that: include: Step 1, obtain the echo signals of the two channels of the synthetic aperture radar and calculate their spectrum, pre-screen the interference signal according to the preset frequency band, and convert the pre-processed spectrum into the time domain to obtain the interference signal with only the interference component; Step 2, determining the cumulative sum of the amplitude differences of the interference signals of the two channels; Step 3: Based on the accumulated sum of amplitude differences 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; Step 4, constructing the two-channel phase difference of the synthetic aperture radar with respect to the azimuth slow time, the range coordinate parameter of the interference source, and the azimuth coordinate parameter; 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 distance coordinate parameter of the interference source is recorded as the known slant distance of the center of the synthetic aperture radar imaging area, and the corresponding azimuth coordinate parameter value is obtained at this time, and the value and the slant distance of the center of the scene constitute a hypothetical coordinate point; Step 6, using the principle that the assumed coordinate point and the actual coordinates of the interference source are in the same dual slope-range difference hyperbola model, the value of the range coordinate parameter is 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 spectrum X i (f,η) corresponds to [Nr p ,Nr q ]] The frequency band data in the range is retained, and the data of the remaining frequency bands are set to zero, thus completing the spectrum preprocessing process.

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, that 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 of 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; after summing the sequence, the cumulative sum ΔI(η) at each slow time η is obtained; Nr is the number of azimuth sampling points.

5. The method for locating interference sources by alternating constraint optimization according to claim 1, characterized in that: The actual azimuth coordinate model of the interference source is constructed and solved based on the accumulated sum of amplitude differences and the equivalent speed of the platform where the synthetic aperture radar is located, and the actual azimuth coordinates of the interference source are obtained, including: 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 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 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 about the azimuth slow time, the range coordinate parameter of the interference source, and the azimuth coordinate parameter is expressed as: Where η is the azimuth slow time, 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 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} The value of the azimuth coordinate parameter The method to determine is: Among them, ||·||1 is to find the L1 norm; δy represents the first blur threshold, and R0 is the slant distance of the scene center.

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, ΔR is the slope range difference hyperbolic model parameter, 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 Wherein, δx is the second fuzzy threshold; The value of the distance coordinate parameter solved in this step The actual distance coordinates of the interference source 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 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 1-9 is implemented.

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