A simultaneous polarization measurement method

Abstract

The present application provides a simultaneous polarization measurement method, belonging to the technical field of radar, and specifically including the following steps: generating a set of quasi-orthogonal baseband waveforms s h (t), s v (t), frequency-converting them to the same frequency and then radiating them from a horizontal polarization antenna and a vertical polarization antenna towards the target to be measured respectively; receiving the signals scattered by the target by using the horizontal and vertical polarization antennas; generating corresponding baseband discrete waveforms s h (t), s v (t); using the iterative adaptive algorithm and s h (t), s v (t) to perform iterative adaptive processing on the signals y h (t), y v (t) received by two polarization receiving channels respectively, and obtaining x h (t), x v (t), x hh (t), x hv (t), x vh (t), x vv (t); using x hh (t), x hv (t), x vh (t), x vv (t) to detect the target and estimate the polarization scattering matrix of the target, and using the estimation result to discriminate the type of the target. Through the processing solution of the present application, the accuracy of simultaneous polarization measurement and the accuracy of target recognition are improved.

Description

Technical Field

[0001] This application relates to the field of radar, and in particular, to a method for simultaneous polarization measurement. Background Art

[0002] The simultaneous polarization measurement system only emits one pulse, which is generally obtained by coherently superimposing two (or more) coded waveforms. Each waveform corresponds to a transmit polarization, and these coded waveforms are orthogonal to each other. In the receiving process, the received waveform is respectively matched with each coded waveform for reception, and the "code division multiple access" method can be used to separate the echoes corresponding to different transmit polarizations. After further processing, the complete target polarization information can be obtained. This simultaneous polarization measurement system proposed by D. Giuli is mainly used for the measurement of the target scattering matrix. It uses two sets of m-sequences corresponding to two orthogonal transmit polarizations respectively. Since the Doppler modulation received by the two transmit polarizations is exactly the same, there is no phase difference between the column elements. Also, since the measurement is completed within one pulse time, the influence of the target decorrelation effect is reduced. These are the main advantages of the simultaneous polarization measurement system.

[0003] However, in order to achieve simultaneous polarization measurement, waveforms with better orthogonality need to be designed, which will result in a longer coding length, thus making the pulse width larger or the bandwidth larger, restricting the application scenarios of the simultaneous polarization measurement technology. Summary of the Invention

[0004] In view of this, this application provides a method for simultaneous polarization measurement, which solves the problems in the prior art and improves the accuracy of simultaneous polarization measurement on the premise of reducing the orthogonality requirements of the signals used in simultaneous polarization measurement.

[0005] A method for simultaneous polarization measurement provided by this application adopts the following technical solutions:

[0006] A method for simultaneous polarization measurement includes the following steps:

[0007] Step 1, generate a set of quasi-orthogonal baseband waveforms 、 , and up-convert them to the same frequency through the horizontal polarization and vertical polarization transmission channels and then radiate them from the horizontal polarization antenna and the vertical polarization antenna towards the target to be measured respectively;

[0008] Step 2, use the horizontal and vertical polarization antennas to receive the signals scattered by the target, and set the signals after A / D sampling as 、 , is the number of range gates;

[0009] Step 3, generate corresponding baseband discrete waveforms according to 、 ​ , , is the number of sampling points within the pulse width;

[0010] Step 4: Use the iterative adaptive algorithm and , to perform iterative adaptive processing on the signals received by the two polarization receiving channels , respectively, to obtain , , , ;

[0011] Step 5: Use , , , to detect the target and estimate the polarization scattering matrix of the target, and use the estimation result to discriminate the type of the target.

[0012] Optionally, step 3 includes:

[0013] Calculate the sampling time of the th point of the baseband discrete waveform according to the echo signal sampling rate , ;

[0014] According to the sampling time of the th point and the baseband waveform , , obtain , .

[0015] Optionally, step 4a: Use , to respectively construct dimensional matrices and as follows:

[0016] ;

[0017] ;

[0018] Step 4b: Use the received signal , and adopt the normalized matched filtering method to pre-estimate the echo component of the horizontally polarized transmitted signal and the echo component of the vertically polarized transmitted signal, to obtain and ; ​

[0019] Step 4c, for the th iteration: The known information is the echo estimation in the th iteration and , for the th range cell, estimate the echo power of each range gate from the echo estimations of each range gate in the previous iteration and arrange them as a diagonal matrix

[0020] ;

[0021] and

[0022] ;

[0023] Furthermore, obtain

[0024] ;

[0025] where is a diagonal matrix with equal diagonal elements, and the value of its diagonal elements is the estimated value of the channel noise power, which can be obtained by averaging the signal powers of each range gate according to and ;

[0026] Obtain the estimated result of the echo component of the horizontally polarized transmitted signal in the middle section of the horizontally polarized receiving channel in the th iteration as:

[0027] ;

[0028] where ;

[0029] Obtain the estimated results at both ends as

[0030] ;

[0031] ;

[0032] where represents the th column in the

[0033] matrix; Obtain the estimated result of the echo component

[0034] of the vertically polarized transmitted signal in the middle section of the horizontally polarized receiving channel as

[0035] The estimated results at both ends are

[0036] ;

[0037] ;

[0038] wherein denotes the th column in the matrix;

[0039] Then, the estimation of the horizontal polarization transmitted signal echo component of each range cell in the th iteration of the horizontal polarization receiving channel is

[0040] ;

[0041] And the estimation of the vertical polarization transmitted signal echo component of each range cell in the th iteration of the horizontal polarization receiving channel is

[0042] ;

[0043] Repeat until stopping after iterations, and the estimation of the horizontal polarization transmitted signal echo component of each range cell in the horizontal polarization receiving channel and the estimation of the vertical polarization transmitted signal echo component of each range cell in the horizontal polarization receiving channel are obtained;

[0044] Step 4d uses the received signal , and pre - estimates the echo component of the horizontal polarization transmitted signal and the echo component of the vertical polarization transmitted signal by using the normalized matched filtering method, and obtains and ;

[0045] Step 4e for the th iteration: The known information is the echo estimations and in the th iteration; For the th range cell, the echo power of each range gate is estimated from the echo estimations of each range gate in the previous iteration and arranged as a diagonal matrix

[0046] ;

[0047] and

[0048] ;

[0049] Furthermore,

[0050] is obtained;

[0051] wherein is a diagonal matrix with equal diagonal elements, and the values of the diagonal elements are the estimated values of the channel noise power, obtained by averaging the signal powers of each range gate according to and ;

[0052] The estimated result of the echo component of the horizontally polarized transmitted signal in the middle section of the vertical receiving channel for the th iteration is ;

[0053] ;

[0054] where ;

[0055] The estimated results at both ends are

[0056] ;

[0057] ;

[0058] where represents the th column in the

[0059] matrix; The estimated result of the echo component of the vertically polarized transmitted signal in the middle section of the vertical polarization receiving channel is

[0060] ;

[0061] The estimated results at both ends are

[0062] ;

[0063] ;

[0064] where represents the th column in the

[0065] matrix; The estimation of the echo component of the horizontally polarized transmitted signal for each range cell in the vertical polarization receiving channel for the

[0066] th iteration is

[0067] ; and the estimation of the echo component of the vertically polarized transmitted signal for each range cell in the vertical polarization receiving channel for the

[0068] th iteration is

[0069] Repeat until iterations are performed and then stop, obtaining the estimation of the horizontal polarization transmitted signal echo component of each range cell in the vertical polarization receiving channel and the estimation of the vertical polarization transmitted signal echo component of each range cell in the vertical polarization receiving channel .

[0070] Optionally, step 4b is performed in the time domain, and , where represents convolution, represents conjugate transpose;

[0071] or it is performed in the frequency domain, and , where , respectively represent fast Fourier transform and inverse fast Fourier transform, represents element-wise multiplication of matrices, represents taking the conjugate of each element of the matrix, represents summing each element of the matrix.

[0072] Optionally, step 4d is performed in the time domain, and ;

[0073] or it is performed in the frequency domain, and .

[0074] Optionally, step 5 is specifically as follows:

[0075] Step 5a, according to , , , , detect the range gate where the target is located ;

[0076] Step 5b, extract the echo signal components corresponding to the range gate , , , from to form a matrix

[0077] ;

[0078] Step 5c, according to obtain the normalized polarization scattering matrix of the target, that is, the co-polarization measurement result.

[0079] Optionally, in step 5a, use the CA-CFAR signal detection method to detect the range gate where the target is located 。

[0080] Optionally, a set of quasi-orthogonal baseband waveforms is generated using a dual-polarization waveform generation module 、 。

[0081] In summary, the present application includes the following beneficial technical effects:

[0082] 1. When the waveform orthogonality in simultaneous polarization measurement of the present application is not ideal, the polarization measurement accuracy is significantly improved;

[0083] 2. For a determined polarization measurement accuracy requirement, the present application can significantly reduce the design difficulty of the waveforms for simultaneous polarization measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0085] Figure 1 is the implementation flowchart of the present application

[0086] Figure 2 is the iterative adaptive algorithm flow of the present application

[0087] Figure 3 is the normalized cross-correlation coefficient between the horizontally and vertically polarized channel quasi-orthogonal transmit signals of the present application

[0088] Figure 4 is the HH component of the target echo signal after traditional matched filtering

[0089] Figure 5 is the HV component of the target echo signal after traditional matched filtering

[0090] Figure 6 is the VH component of the target echo signal after traditional matched filtering of the present application

[0091] Figure 7 is the VV component of the target echo signal after traditional matched filtering of the present application

[0092] Figure 8 is the HH component of the target echo signal after iterative adaptive processing of the present application

[0093] Figure 9 The HV component after iterative adaptive processing of the target echo signal described in this application

[0094] Figure 10 The VH component after iterative adaptive processing of the target echo signal described in this application

[0095] Figure 11 The VV component after iterative adaptive processing of the target echo signal described in this application Detailed implementation manners

[0096] The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0097] The following uses specific specific examples to illustrate the implementation manners of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. This application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without making creative efforts belong to the scope of protection of this application.

[0098] It should be noted that the following describes various aspects of the embodiments within the scope of the appended claims. It should be obvious that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on this application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, this device can be implemented and this method can be practiced using other structures and / or functionality in addition to one or more of the aspects described herein.

[0099] It should also be noted that the drawings provided in the following embodiments only illustrate the basic concept of this application in a schematic manner. The drawings only show the components related to this application and are not drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in its actual implementation can be an arbitrary change, and the component layout type may also be more complex.

[0100] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0101] An embodiment of the present application provides a simultaneous polarization measurement method.

[0102] As Figure 1 and Figure 2 shown, a simultaneous polarization measurement method includes the following steps:

[0103] Step 1: Generate a set of quasi-orthogonal baseband waveforms , , and up-convert them to the same frequency on the horizontal polarization and vertical polarization transmission channels, and then radiate them from the horizontal polarization antenna and the vertical polarization antenna towards the target to be measured respectively.

[0104] Step 2: Use the horizontal and vertical polarization antennas to receive the signals scattered by the target, and set the signals after A / D sampling as , , is the number of range gates.

[0105] Step 3: Generate corresponding baseband discrete waveforms , according to , , is the number of samples within the pulse width.

[0106] Step 4: Use the iterative adaptive algorithm and , , and perform iterative adaptive processing on the signals , received by the two polarization receiving channels respectively to obtain , , , .

[0107] Step 5: Use , , , to detect the target and estimate the polarization scattering matrix of the target, and use the estimation result to discriminate the type of the target.

[0108] The radar uses dual-polarization transmit / receive channels and a dual-polarization antenna, and simultaneously transmits and receives co-frequency quasi-orthogonal waveforms. Due to the variable polarization effect of various targets, the signal received by the horizontal polarization receive channel will include both the signal component whose original transmitted signal is horizontally polarized and remains horizontally polarized after being scattered by the target, and the signal component whose original transmitted signal is vertically polarized but becomes horizontally polarized after being scattered by the target. Similarly, the signal received by the vertical polarization receive channel of the radar includes both the signal component whose original transmitted signal is vertically polarized and remains vertically polarized after being scattered by the target, and the signal component whose original transmitted signal is horizontally polarized but becomes vertically polarized after being scattered by the target. By using the iterative adaptive algorithm to process the signals received by each polarization receive channel, the echo components of different transmitted polarizations contained in each receive channel can be separated, and a total of four components are obtained, thereby realizing simultaneous polarization measurement.

[0109] First, use the dual-polarization waveform generation module to generate a set of quasi-orthogonal baseband waveforms 、 ,and up-convert them to the same frequency on the horizontal polarization and vertical polarization transmit channels and then radiate them from the horizontal polarization antenna and the vertical polarization antenna towards the target to be measured, where the subscripts and represent horizontal polarization and vertical polarization respectively (the same below); then, use the horizontal polarization antenna and the vertical polarization antenna to receive the echo signals scattered by the target. Let the echo signals received by the horizontal polarization antenna and the vertical polarization antenna after A / D sampling be 、 respectively, and L is the number of range gates; next, use the iterative adaptive algorithm to process the received 、 respectively, and obtain 、 、 、 Finally, perform CFAR detection on 、 、 、 ,and extract the four signal components in the range gate passing the detection point 、 、 、 ,and based on this, obtain the polarization scattering characteristics of the target through simple normalization calculation, thereby completing simultaneous polarization measurement.

[0110] Since the iterative adaptive algorithm can optimize the suppression of the undesired signal when the desired signal and the undesired signal are non-orthogonal, therefore, by using the iterative adaptive algorithm and the current co-frequency quasi-orthogonal simultaneous polarization measurement waveform, the accuracy of polarization measurement can be greatly improved. Moreover, by using the iterative adaptive algorithm, under the same polarization measurement accuracy requirement, the design difficulty of the simultaneous polarization measurement waveform can be greatly reduced.

[0111] Specifically, in step 1, a group of quasi-orthogonal baseband waveforms are generated by using the dual-polarization waveform generation module. 、 . It should be noted that the quasi-orthogonal baseband waveforms are cross-correlated compared with the orthogonal baseband waveforms, where the subscripts and represent horizontal polarization and vertical polarization respectively, being the fast time.

[0112] Specifically, the said step 3 includes:

[0113] Calculate the sampling time of the -th point of the baseband discrete waveform according to the echo signal sampling rate , .

[0114] According to the sampling time of the -th point and the baseband waveforms 、 , obtain 、 .

[0115] Specifically, step 4 includes:

[0116] Step 4a, use 、 , , to construct the -dimensional matrices and as follows:

[0117] ;

[0118] ;

[0119] Step 4b, use the received signal , and adopt the normalized matched filtering method to pre-estimate the echo components of the horizontally polarized transmitted signal and the echo components of the vertically polarized transmitted signal, and obtain and ;

[0120] Step 4c, for the Iteration: The known information is Echo estimation in iteration and . The echo power of each range gate is estimated from the echo of each range gate in the last iteration and arranged into a diagonal matrix

[0121] ;

[0122] and

[0123] ;

[0124] Then seek

[0125] ;

[0126] in It is a diagonal matrix with equal diagonal elements. The diagonal element value is the estimated value of the channel noise power, which can be calculated according to and The signal power of each range gate is averaged;

[0127] Find the first The echo component of the horizontally polarized transmitted signal in the middle section of the iterative horizontally polarized receiving channel The estimated results are:

[0128] ;

[0129] in ;

[0130] The estimated results at both ends are

[0131] ;

[0132] ;

[0133] in express The first List;

[0134] Obtain the echo component of the vertical transmission signal in the middle section of the horizontal polarization receiving channel The estimated result is

[0135] ;

[0136] The estimated results at both ends are

[0137] ;

[0138] ;

[0139] Among them represents the th column in the matrix;

[0140] Then, the estimation of the echo component of the horizontal polarization transmitted signal for each range cell in the th iteration of the horizontal polarization receiving channel is

[0141] ;

[0142] And the estimation of the echo component of the vertical polarization transmitted signal for each range cell in the th iteration of the horizontal polarization receiving channel is

[0143] ;

[0144] Repeat until stopping after iterations, and the estimation of the echo component of the horizontal polarization transmitted signal for each range cell in the horizontal polarization receiving channel and the estimation of the echo component of the vertical polarization transmitted signal for each range cell in the horizontal polarization receiving channel are obtained;

[0145] Step 4d Use the received signal , and adopt the normalized matched filtering method to pre-estimate the echo component of the horizontal polarization transmitted signal and the echo component of the vertical polarization transmitted signal, and obtain and ;

[0146] Step 4e For the th iteration: The known information is the echo estimation and in the th iteration; For the rd range cell, estimate the echo power of each range gate from the echo estimations of each range gate in the previous iteration and arrange them into a diagonal matrix

[0147] ;

[0148] and

[0149] ;

[0150] Furthermore, obtain

[0151] ;

[0152] Among them is a diagonal matrix with equal diagonal elements, and the values of the diagonal elements are the estimated values of the channel noise power, obtained by averaging the signal powers of each range gate according to and ;

[0153] The estimated result of the echo component of the horizontally polarized transmitted signal in the middle section of the vertical receiving channel for the th iteration is ;

[0154] ;

[0155] where ;

[0156] The estimated results at both ends are

[0157] ;

[0158] ;

[0159] where represents the th column in the matrix;

[0160] The estimated result of the echo component of the vertically polarized transmitted signal in the middle section of the vertical polarization receiving channel is ;

[0161] ;

[0162] The estimated results at both ends are

[0163] ;

[0164] ;

[0165] where represents the th column in the matrix;

[0166] The estimation of the echo component of the horizontally polarized transmitted signal for each range cell in the vertical polarization receiving channel for the th iteration is

[0167] ;

[0168] And the estimation of the echo component of the vertically polarized transmitted signal for each range cell in the vertical polarization receiving channel for the th iteration is

[0169] ;

[0170] Repeat until Stop after the next iteration to obtain the estimation of the horizontal polarization transmitted signal echo components of each range cell in the vertical polarization receiving channel and the estimation of the vertical polarization transmitted signal echo components of each range cell in the vertical polarization receiving channel .

[0171] Among them, step 4b is performed in the time domain, and , where represents convolution, represents conjugate transpose;

[0172] It can also be performed in the frequency domain, and , where 、 represent fast Fourier transform and inverse fast Fourier transform respectively, represents element-by-element multiplication of matrices, represents taking the conjugate of each element of the matrix, represents summing each element of the matrix.

[0173] The said step 4d is performed in the time domain, and ;

[0174] It can also be performed in the frequency domain, and .

[0175] The specific steps 5 include:

[0176] Step 5a, according to 、 、 、 , detect the range gate where the target is located ;

[0177] Step 5b, extract the echo signal components corresponding to the range gate 、 、 、 from to form a matrix

[0178] ;

[0179] Step 5c, according to obtain the normalized polarization scattering matrix of the target, that is, the co-polarization measurement result.

[0180] Among them, in step 5a, the CA-CFAR signal detection method is used to detect the range gate where the target is located . In other embodiments, CFAR or other signal detection methods can also be used to detect the range gate where the target is located .

[0181] This application utilizes the advantages of the iterative adaptive algorithm to optimally and adaptively suppress undesired signals and quasi-orthogonal waveforms for simultaneous polarization measurement. This application can perform high-precision simultaneous polarization measurement under the condition that the orthogonality performance of the simultaneous polarization measurement waveform is not ideal. Simulation scenario: The horizontal polarization channel and the vertical polarization channel respectively transmit phase-coded signals with a code length of 200 at the same time, and the normalized cross-correlation coefficient of the two signals is as Figure 3 shown. The polarization scattering matrix of the target to be measured is , and the echo signal-to-noise ratio is 25 dB.

[0182] To prove that this application can greatly improve the performance of simultaneous polarization measurement when the waveforms are quasi-orthogonal, the simultaneous polarization measurement results based on the traditional matched filtering algorithm and the simultaneous polarization measurement results based on the iterative adaptive algorithm are respectively simulated, as shown in Figures 4 to 7 and Figures 8 to 11 shown.

[0183] From Figures 4 to 7 it can be seen that when using the matched filtering method for simultaneous polarization measurement, due to the insufficient orthogonality performance of the waveforms, the errors of the HV component and VH component of the target scattered echo are relatively large. From Figures 8 to 11 it can be seen that when using the adaptive iterative algorithm for simultaneous polarization measurement, the components of the target echo can be clearly obtained.

[0184] The echo obtained by using the two methods respectively is used for target detection and simultaneous polarization measurement. The measurement result of the target polarization scattering matrix obtained based on the matched filtering method is The measurement result of the target polarization scattering matrix obtained based on the simultaneous polarization measurement method based on the iterative adaptive method proposed in this application is . By comparison, it can be seen that by using the simultaneous polarization measurement method proposed in this invention, very high-precision simultaneous polarization measurement results can indeed be obtained when the waveforms are not ideally orthogonal.

[0185] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in this application should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A simultaneous polarization measurement method, characterized in that, including the following steps: Step 1, generate a set of quasi-orthogonal baseband waveforms , , and up-convert them to the same frequency on the horizontal polarization and vertical polarization transmission channels and then radiate them from the horizontal polarization antenna and the vertical polarization antenna towards the target to be measured respectively; Step 2: Receive the signals scattered by the target using horizontal and vertical polarization antennas, and set the signals after A / D sampling as and , where is the number of range gates; Step 3, according to , generate corresponding baseband discrete waveforms , , where is the number of sampling points within the pulse width; Step 4, using the iterative adaptive algorithm and , , perform iterative adaptive processing on the signals received by the two polarization receiving channels , respectively, to obtain , , , ; Step 5, using , , , , detect the target and estimate the polarization scattering matrix of the target, and use the estimation result to discriminate the type of the target.

2. The simultaneous polarization measurement method according to claim 1, wherein The said step 3 includes: According to the sampling rate of the echo signal Calculate the sampling time of the point of the baseband discrete waveform , ; According to the sampling moment of the point and the baseband waveform , , we obtain , .

3. The simultaneous polarization measurement method according to claim 1, wherein The said step 4 specifically is: Step 4a, using , , , respectively construct -dimensional matrices and as follows: ； ； Step 4b, using the received signal , adopting the normalized matched filtering method to pre-estimate the echo component of the horizontally polarized transmitted signal and the echo component of the vertically polarized transmitted signal , obtaining and ; Step 4c, for the th iteration: The known information is the echo estimation in the th iteration and , for the th range cell, estimate the echo power of each range gate from the echo estimations of each range gate in the previous iteration and arrange them into a diagonal matrix ； and ； further obtain ； Among them is a diagonal matrix with equal diagonal elements, and the value of its diagonal elements is the estimated value of the channel noise power, which can be obtained according to and the average of the signal powers of each range gate; Obtain the echo component of the horizontally polarized transmit signal in the middle section of the horizontally polarized receiving channel at the th iteration, and the estimation result is: ； Among them ; The estimated results at both ends are obtained as ； ； wherein denotes the th column in the matrix; Obtain the echo component of the vertically transmitted signal in the middle section of the horizontally polarized receiving channel The estimation result is ； The estimated results at both ends are ； ； Among them denotes the th column in the matrix; Then, the estimation of the echo component of the horizontally polarized transmitted signal for each range cell in the horizontally polarized receiving channel at the th iteration is ； and the estimation of the echo component of the vertically polarized transmitted signal for each range cell in the horizontally polarized receiving channel at the th iteration is ； Repeat until after iterations and then stop, to obtain the estimates of the echo components of the horizontally polarized transmitted signals for each range cell of the horizontally polarized receiving channel and the estimates of the echo components of the vertically polarized transmitted signals for each range cell of the horizontally polarized receiving channel ; Step 4d utilizes the received signal , and uses the normalized matched filtering method to pre-estimate the echo component of the horizontally polarized transmitted signal and the echo component of the vertically polarized transmitted signal to obtain and ; Step 4e for the iteration: The known information is the echo estimation in the th iteration and ; For the range cells, estimate the echo power of each range gate from the echo estimations of each range gate in the previous iteration and arrange them as a diagonal matrix ； and ； further obtain ； Among them is a diagonal matrix with equal diagonal elements, and the value of its diagonal elements is the estimated value of the channel noise power, which is obtained by averaging the signal powers of each and range gate; Obtain the echo component of the horizontally polarized transmitted signal in the middle section of the vertical receiving channel for the iteration, and the estimated result is ； Among them ; The estimated results at both ends are obtained as ； ； wherein denotes the th column in the matrix; Obtain the echo component of the vertical transmission signal in the middle section of the vertical polarization receiving channel The estimated result is ； The estimated results at both ends are ； ； Among them denotes the th column in the matrix; Obtain the estimation of the echo component of the horizontally polarized transmitted signal for each range cell in the vertically polarized receiving channel at the ； and the estimation of the vertical polarization transmitted signal echo component of each range cell in the vertical polarization receiving channel for the th iteration ； Repeat until stopping after iterations, obtaining the estimates of the horizontal polarization transmitted signal echo components for each range cell of the vertical polarization receiving channel and the estimates of the vertical polarization transmitted signal echo components for each range cell of the vertical polarization receiving channel .

4. The simultaneous polarization measurement method according to claim 3, characterized in that, The said step 4b is carried out in the time domain, and , where represents convolution, represents conjugate transpose; or in the frequency domain, and where and represent the fast Fourier transform and the inverse fast Fourier transform respectively, represents element-by-element multiplication of matrices, represents taking the conjugate of each element of the matrix, represents summing each element of the matrix.

5. The simultaneous polarization measurement method according to claim 3, characterized in that The said step 4d is carried out in the time domain, and ; or in the frequency domain, and .

6. The simultaneous polarization measurement method according to claim 1, wherein The specific content of step 5 is: Step 5a, according to , , , , detect the distance gate where the target is located ; Step 5b, extract the echo signal components corresponding to the distance from , , , , and form a matrix of the echo signal components corresponding to the distance from ​ ； Step 5c, according to obtain the normalized polarization scattering matrix of the target, that is, the co-polarization measurement result.

7. The simultaneous polarization measurement method according to claim 6, wherein In the said step 5a, the distance gate where the target is located is detected by using the CA-CFAR signal detection method .

8. The simultaneous polarization measurement method according to claim 1, characterized in that, In the step 1, a set of quasi-orthogonal baseband waveforms is generated by using a dual-polarization waveform generation module , .

Images