Mainlobe clutter and interference suppression method based on space-time polarization adaptive processing

Abstract

The present invention relates to the field of signal processing technology, and provides a main lobe clutter and interference suppression method based on space-time polarization adaptive processing. The method includes: constructing polarization dual-channel array element-Doppler domain echo data; calculating the interference or clutter normalized Stokes subvector of each Doppler channel according to the polarization dual-channel array element-Doppler domain echo data; determining the target polarization space-time steering vector of each Doppler channel according to the interference or clutter normalized Stokes subvector; using the target polarization space-time steering vector and the echo space-time polarization covariance matrix, calculating the space-time polarization joint processing weight vector; applying the space-time polarization joint processing weight vector to the echo data of each Doppler channel to obtain processed output data. The present invention can filter out interference by utilizing the difference in polarization characteristics between interference and target when the interference and target cannot be well distinguished in the space-time domain, thereby more efficiently detecting the target signal and improving the probability of target detection.

Description

Technical Field

[0001] The invention relates to the technical field of signal processing, and in particular to a main lobe clutter and interference suppression method based on space-time polarization adaptive processing. Background Art

[0002] Noise suppression jamming is a common way for a jammer to emit a strong jamming power noise signal to suppress the useful signal of the radar. The jamming signal is spatially correlated, and its spatial sampling signal is similar to the point target signal; on the other hand, the jamming signal is uncorrelated in the time domain, and the jamming sampling signal between pulses is white noise, which can make the target signal detected by the radar search submerged in the noise interference and unable to detect the target. Compared with land-based radars, airborne radars not only face jamming signals, but also strong clutter backgrounds. When noise suppression jamming enters the receiver from the radar sidelobe, it can be suppressed using beam-domain space-time adaptive processing technology. However, in some cases, the jamming signal enters from the radar main lobe. At this time, the space-time characteristics of the target, clutter, and interference are similar and difficult to distinguish, and cannot be suppressed by traditional space-time adaptive processing technology.

[0003] In view of this, overcoming the defects of the prior art is an urgent problem to be solved in the field of this technology. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a main lobe clutter and interference suppression method based on space-time polarization adaptive processing, so as to achieve interference suppression in a scenario where the interference and the target cannot be well distinguished in the space-time domain.

[0005] The present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a main lobe clutter and interference suppression method based on space-time polarization adaptive processing, comprising:

[0007] According to the echo element-pulse domain data of the horizontal polarization channel and the echo element-pulse domain data of the vertical polarization channel, polarization dual-channel element-Doppler domain echo data are constructed;

[0008] Calculating interference or clutter normalized Stokes subvectors of each Doppler channel according to the polarized dual-channel array element-Doppler domain echo data;

[0009] Determining the target polarization space-time steering vector of each Doppler channel according to the interference or clutter normalized Stokes subvector;

[0010] Calculate the space-time polarization joint processing weight vector using the target polarization space-time steering vector and the echo space-time polarization covariance matrix;

[0011] The space-time polarization joint processing weight vector is applied to the echo data of each Doppler channel to obtain processed output data.

[0012] Preferably, constructing polarization dual-channel element-Doppler domain echo data according to the echo element-pulse domain data of the horizontal polarization channel and the echo element-pulse domain data of the vertical polarization channel specifically includes:

[0013] For l Echo array element-pulse domain data of a range unit in the horizontal polarization channel Pulse-Doppler processing is performed to obtain l In the distance unit k Horizontally polarized channel array element of a Doppler channel - Doppler domain echo data ;

[0014] For l Echo array element-pulse domain data of a range unit in the vertical polarization channel Pulse-Doppler processing is performed to obtain l In the distance unit k Doppler channel vertical polarization channel array element - Doppler domain echo data ;

[0015] Use the l In the distance unit k Horizontally polarized channel array element of a Doppler channel - Doppler domain echo data and l In the distance unit k Doppler channel vertical polarization channel array element - Doppler domain echo data , construct the l In the distance unit k Polarization dual-channel array element-Doppler domain echo data of Doppler channels .

[0016] Preferably, the l In the distance unit k Horizontally polarized channel array element of a Doppler channel - Doppler domain echo data ;

[0017] in, represents the Hadamard product, represents the time domain cone weight vector, represents the airspace cone elimination weight vector, For the k The time-domain steering vector of each Doppler channel, , For the kThe normalized Doppler center frequency of the Doppler channel, K It is the number of pulses emitted by the radar in one pulse repetition period. is the target airspace guidance vector, and its mathematical expression is , the spatial frequency of the main lobe pointing direction is , N is the number of sub-arrays.

[0018] Preferably, the l In the distance unit k Doppler channel vertical polarization channel array element - Doppler domain echo data ;

[0019] in, represents the Hadamard product, represents the time domain cone weight vector, represents the airspace cone elimination weight vector, For the k The time-domain steering vector of each Doppler channel, K is the number of pulses emitted by the radar in one pulse repetition period; is the target airspace guidance vector, and its mathematical expression is , the spatial frequency of the main lobe pointing direction is , N is the number of sub-arrays.

[0020] Preferably, the calculating the interference or clutter normalized Stokes subvector of each Doppler channel according to the polarized dual-channel array element-Doppler domain echo data specifically includes:

[0021] Calculate the l The distance k The polarization coherence vector of the Doppler channel ;in, For the l In the distance unit k Polarization dual-channel array element-Doppler domain echo data of Doppler channels, represents the complex conjugate, represents the Hadamard product;

[0022] Calculate the l In the distance unit k The Stokes vector of the echo signal of the Doppler channel ;in, ;

[0023] No. l In the distance unit k The Stokes vector of the echo signal of the Doppler channel Also expressed as , calculate the l Stokes subvector normalized by distance units ;in, for The sub-vector of ; For the l In the distance unit k The echo power of each Doppler channel;

[0024] In the l Distance unit before and after L The adjacent distance unit is taken as the l training samples of distance units, l The normalized Stokes subvectors of the training samples of the distance units are averaged and the average value is used as the l In the distance unit k The normalized Stokes subvector of interference or clutter in a Doppler channel .

[0025] Preferably, in a clutter clear area, the interference or clutter normalized Stokes subvector is a normalized Stokes subvector of interference;

[0026] In the clutter region, the interference or clutter normalized Stokes subvector is a normalized Stokes subvector of a mixed signal of clutter and interference.

[0027] Preferably, determining the target polarization space-time steering vector of each Doppler channel according to the interference or clutter normalized Stokes subvector specifically includes:

[0028] In order to minimize the interference signal power after processing, and Orthogonal in the polarization domain, that is, ;in, For the l In the distance unit k The normalized Stokes subvector of interference or clutter in a Doppler channel, For the l In the distance unit k The target normalized Stokes subvector of a Doppler channel, diag{} represents a diagonal matrix;

[0029] Will Convert to Jones vector and get l In the distance unit k The target polarization space-time steering vector of the Doppler channel ;in, For the lIn the distance unit k The optimal polarization-filtered Stokes vector for a Doppler channel, ; For the l In the distance unit k The polarization ratio of the Doppler channel, .

[0030] Preferably, the using the target polarization space-time steering vector and the echo space-time polarization covariance matrix to calculate the space-time polarization joint processing weight vector specifically includes:

[0031] Calculate the l In the distance unit k The target space-time polarization steering estimation vector of the Doppler channel ;in, For the l In the distance unit k The target polarization space-time steering vector of the Doppler channel, For the k The time-domain steering vector of each Doppler channel, For the l The spatial steering vector of the main lobe pointing direction of each range unit, , For the l The spatial frequency of the main lobe pointing direction of each range unit;

[0032] Calculate the l In the distance unit k The weight vector of space-time-polarization joint processing of Doppler channels ;in, is the echo space-time polarization covariance matrix.

[0033] Preferably, the echo space-time polarization covariance matrix It is to use the adjacent The distance unit is calculated, specifically:

[0034] ;in, For the l Array element-pulse domain echo data of range units, Not less than 2 times the system degrees of freedom.

[0035] Preferably, the applying the space-time polarization joint processing weight vector to the echo data of each Doppler channel to obtain processed output data specifically includes:

[0036] Use l In the distance unit kThe weight vector of the space-time polarization joint processing of the Doppler channels is l Distance unit k The echo data of the Doppler channels are processed jointly in space and time to obtain the l Distance unit k The processed output data of each Doppler channel ;in, For the l Array element-pulse domain echo data of range units, For the l In the distance unit k The weight vector for the joint space-time and polarization processing of the Doppler channels.

[0037] In a second aspect, the present invention further provides a main lobe clutter and interference suppression device based on space-time polarization adaptive processing, which is used to implement the main lobe clutter and interference suppression method based on space-time polarization adaptive processing described in the first aspect, and the device includes:

[0038] At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the processor to execute the main lobe clutter and interference suppression method based on space-time polarization adaptive processing as described in the first aspect.

[0039] In a third aspect, the present invention further provides a non-volatile computer storage medium, wherein the computer storage medium stores computer executable instructions, and the computer executable instructions are executed by one or more processors to complete the method described in the first aspect.

[0040] In a fourth aspect, a chip is provided, comprising: a processor and an interface, for calling and running a computer program stored in the memory from a memory, and executing the method of the first aspect.

[0041] According to a fifth aspect, a computer program product comprising instructions is provided. When the instructions are executed on a computer or a processor, the computer or the processor executes the method according to the first aspect.

[0042] The present invention combines polarization anti-interference technology with space-time adaptive processing technology. When the interference and the target cannot be well distinguished in the space-time domain, the difference in polarization characteristics between the interference and the target can be used to filter out the interference, so as to suppress the main lobe interference while suppressing the main lobe clutter to a lower level, thereby more efficiently detecting the target signal and improving the target detection probability. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 It is a flow chart of a first main lobe clutter and interference suppression method based on space-time polarization adaptive processing provided by an embodiment of the present invention;

[0045] Figure 2 It is a flow chart of a second main lobe clutter and interference suppression method based on space-time polarization adaptive processing provided by an embodiment of the present invention;

[0046] Figure 3 It is a flow chart of a third main lobe clutter and interference suppression method based on space-time polarization adaptive processing provided by an embodiment of the present invention;

[0047] Figure 4 is a schematic diagram of a main lobe clutter and interference suppression method based on space-time polarization adaptive processing provided by an embodiment of the present invention;

[0048] Figure 5 It is a flowchart of a fourth main lobe clutter and interference suppression method based on space-time polarization adaptive processing provided by an embodiment of the present invention;

[0049] Figure 6 It is a schematic diagram of the architecture of a main lobe clutter and interference suppression device based on space-time polarization adaptive processing provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0051] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as open inclusion, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner, that is, although they may be carried in the embodiments or examples of the above terms due to reasons such as the order and position of appearance, it is not limited to that they can be carried in combination by one embodiment or example.

[0052] In the description of the present invention, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, the meaning of "multiple" is two or more. In addition, for example, the same type of nouns may be described as two independent individuals by adding "A" and "B" at the end. In this case, the corresponding features defined as "A" and "B" are only used to distinguish the same type of individuals for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.

[0053] In the description of the present invention, the expression "A and / or B" (where A and B are used to formally represent specific characteristic contents) is involved, and the corresponding expressions include the following three combinations: only A, only B, and a combination of A and B.

[0054] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0055] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0056] Embodiment 1:

[0057] Embodiment 1 of the present invention provides a main lobe clutter and interference suppression method based on space-time polarization adaptive processing, such as Figure 1As shown, including:

[0058] In step 201, polarization dual-channel element-Doppler domain echo data is constructed according to the echo element-pulse domain data of the horizontal polarization channel and the echo element-pulse domain data of the vertical polarization channel; the echo element-pulse domain data is also called echo signal data, and the polarization dual-channel element-Doppler domain echo data is also called polarization dual-channel data.

[0059] In step 202, the interference or clutter normalized Stokes subvector of each Doppler channel is calculated according to the polarization dual-channel array element-Doppler domain echo data.

[0060] In step 203, the target polarization space-time steering vector of each Doppler channel is determined according to the interference or clutter normalized Stokes sub-vector.

[0061] In step 204, the target polarization space-time steering vector and the echo space-time polarization covariance matrix are used to calculate a space-time polarization joint processing weight vector; the space-time polarization joint processing weight vector is also called a space-time polarization adaptive processing weight vector.

[0062] In step 205, the space-time polarization joint processing weight vector is applied to the echo data of each Doppler channel to obtain processed output data.

[0063] This embodiment combines polarization anti-interference technology with space-time adaptive processing technology, so that when the interference and the target cannot be well distinguished in the space-time domain, the difference in polarization characteristics between the interference and the target can be used to filter out interference. That is, interference suppression is achieved in the scenario where the interference and the target cannot be well distinguished in the space-time domain, so that the main lobe clutter can be suppressed to a lower level while suppressing the main lobe interference, thereby more efficiently detecting the target signal and improving the target detection probability.

[0064] In an actual application scenario, the polarization dual-channel element-Doppler domain echo data is constructed according to the echo element-pulse domain data of the horizontal polarization channel and the echo element-pulse domain data of the vertical polarization channel, such as Figure 2 As shown, specifically including:

[0065] In step 301, l Echo array element-pulse domain data of a range unit in the horizontal polarization channel Pulse-Doppler processing is performed to obtain l In the distance unit k Horizontally polarized channel array element of a Doppler channel - Doppler domain echo data .

[0066] In step 302, lEcho array element-pulse domain data of a range unit in the vertical polarization channel Pulse-Doppler processing is performed to obtain l In the distance unit k Doppler channel vertical polarization channel array element - Doppler domain echo data .

[0067] In step 303, using the l In the distance unit k Horizontally polarized channel array element of a Doppler channel - Doppler domain echo data and l In the distance unit k Doppler channel vertical polarization channel array element - Doppler domain echo data , construct the l In the distance unit k Polarization dual-channel array element-Doppler domain echo data of Doppler channels .

[0068] Among them, the l In the distance unit k Horizontally polarized channel array element of a Doppler channel - Doppler domain echo data .

[0069] in, represents the Hadamard product, represents the time domain cone weight vector, represents the airspace cone elimination weight vector, For the k The time-domain steering vector of each Doppler channel, , For the k The normalized Doppler center frequency of the Doppler channel, K It is the number of pulses emitted by the radar in one pulse repetition period. is the target airspace guidance vector, and its mathematical expression is , the spatial frequency of the main lobe pointing direction is , N is the number of sub-arrays.

[0070] The said l In the distance unit k Doppler channel vertical polarization channel array element - Doppler domain echo data .

[0071] in, represents the Hadamard product, represents the time domain cone weight vector, represents the airspace cone elimination weight vector, For the k The time-domain steering vector of each Doppler channel, K It is the number of pulses emitted by the radar in one pulse repetition period. is the target airspace guidance vector, and its mathematical expression is , the spatial frequency of the main lobe pointing direction is , N is the number of sub-arrays.

[0072] In an optional implementation, the interference or clutter normalized Stokes subvector of each Doppler channel is calculated based on the polarized dual-channel array element-Doppler domain echo data, such as Figure 3 As shown, specifically including:

[0073] In step 401, calculate l The distance k The polarization coherence vector of the Doppler channel ;in, For the l In the distance unit k Polarization dual-channel array element-Doppler domain echo data of Doppler channels, represents the complex conjugate, Denotes the Hadamard product.

[0074] In step 402, calculate the l In the distance unit k The Stokes vector of the echo signal of the Doppler channel ;in, .

[0075] In step 403, l In the distance unit k The Stokes vector of the echo signal of the Doppler channel Also expressed as , calculate the l Stokes subvector normalized by distance units ;in, for The sub-vector of ; For the l In the distance unit k The echo power of each Doppler channel.

[0076] In step 404, l Distance unit before and after L The adjacent distance unit is taken as the l training samples of distance units, lThe normalized Stokes subvectors of the training samples of the distance units are averaged and the average value is used as the l In the distance unit k The normalized Stokes subvector of interference or clutter in a Doppler channel The value of L is obtained by those skilled in the art based on empirical analysis.

[0077] Among them, in the clutter clear area, the interference or clutter normalized Stokes subvector is the normalized Stokes subvector of the interference; in the clutter area, the interference or clutter normalized Stokes subvector is the normalized Stokes subvector of the clutter and interference mixed signal.

[0078] In one embodiment, determining the target polarization space-time steering vector of each Doppler channel according to the interference or clutter normalized Stokes subvector specifically includes:

[0079] In order to minimize the interference signal power after processing, and Orthogonal in the polarization domain, that is, ;in, For the l In the distance unit k The normalized Stokes subvector of interference or clutter in a Doppler channel, For the l In the distance unit k The target normalized Stokes subvector of each Doppler channel, diag{} represents a diagonal matrix.

[0080] Will Convert to Jones vector and get l In the distance unit k The target polarization space-time steering vector of the Doppler channel ;in, For the l In the distance unit k The optimal polarization-filtered Stokes vector for a Doppler channel, ; For the l In the distance unit k The polarization ratio of the Doppler channel, .

[0081] In a specific application scenario, the use of the target polarization space-time steering vector and the echo space-time polarization covariance matrix to calculate the space-time polarization joint processing weight vector specifically includes:

[0082] Calculate the l In the distance unitk The target space-time polarization steering estimation vector of the Doppler channel ;in, For the l In the distance unit k The target polarization space-time steering vector of the Doppler channel, For the k The time-domain steering vector of each Doppler channel, For the l The spatial steering vector of the main lobe pointing direction of each range unit, , For the l The spatial frequency of the main lobe pointing direction of each range unit.

[0083] Calculate the l In the distance unit k The weight vector of space-time-polarization joint processing of Doppler channels ;in, is the echo space-time polarization covariance matrix.

[0084] Among them, the echo space-time polarization covariance matrix It is to use the adjacent The distance unit is calculated, specifically:

[0085] ;in, For the l Array element-pulse domain echo data of range units, The value of is obtained by those skilled in the art based on empirical analysis, and Not less than 2 times the system degrees of freedom.

[0086] In an actual application scenario, applying the space-time polarization joint processing weight vector to the echo data of each Doppler channel to obtain processed output data specifically includes:

[0087] Use l In the distance unit k The weight vector of the space-time polarization joint processing of the Doppler channels is l Distance unit k The echo data of the Doppler channels are processed jointly in space and time to obtain the l Distance unit k The processed output data of each Doppler channel ;in, For the l Array element-pulse domain echo data of range units, For the l In the distance unit kThe weight vector for the joint space-time and polarization processing of the Doppler channels.

[0088] This embodiment first performs pulse-Doppler processing on the echo element-pulse domain data of the horizontal and vertical polarization channels respectively, and then estimates the interference or clutter normalized Stokes subvectors of each Doppler channel based on the element-Doppler domain echo data of the horizontal and vertical polarization channels, and determines the target polarization space-time steering vector of each Doppler channel based on the interference or clutter normalized Stokes subvector, and finally uses the estimated echo space-time polarization covariance matrix and the target polarization space-time steering vector to calculate the space-time polarization adaptive processing weight vector and perform space-time polarization joint processing, thereby achieving the simultaneous suppression of main lobe clutter and noise suppression of main lobe interference. Compared with the traditional adaptive polarization cancellation method, this embodiment can suppress the main lobe clutter more effectively while suppressing the main lobe interference, thereby improving the detection probability of the target signal.

[0089] Embodiment 2:

[0090] The present invention is based on the method described in Example 1, combined with specific application scenarios, and uses technical descriptions in related scenarios to illustrate the implementation process of the present invention in characteristic scenarios.

[0091] This embodiment is as follows Figure 4 For example, the application scenario shown in the figure assumes that the phased array array of the airborne radar is M OK N A rectangular planar array of columns, synthesized by column N Each array element is an orthogonal dual-channel polarization sensitive array element. The horizontal polarization channel is written as the H channel, and the vertical polarization channel is written as the V channel. The spacing between the radar row and column elements is equal and the spacing is d , the radar operating wavelength is , the radar pulse repetition frequency is , the number of pulses emitted by the radar in one pulse repetition period is K , the aircraft height and speed are and , the equivalent radius of the Earth is R e The aircraft flies along the positive Y axis, and the first l The distance ring i The azimuth of the clutter block is , on the ground l The top-down view of the clutter block of the range ring is , the distance between the interference source and the radar is , the azimuth of the interference direction is , the pitch angle is .

[0092] This embodiment provides a main lobe clutter and interference suppression method based on space-time polarization adaptive processing, such as Figure 5 As shown, specifically including:

[0093] In step 501, pulse-Doppler processing is performed on the echo element-pulse domain data of the horizontal and vertical polarization channels respectively.

[0094] In step 502, the element-Doppler domain echo data of the horizontal and vertical polarization channels obtained in step 501 are used to estimate the interference or clutter normalized Stokes subvector of each Doppler channel.

[0095] In step 503, the interference or clutter normalized Stokes subvector obtained in step 502 is used to determine the target polarization space-time steering vector of each Doppler channel.

[0096] In step 504, the space-time polarization adaptive processing weight vector is calculated using the target polarization space-time steering vector obtained in step 503 and the estimated echo space-time polarization covariance matrix.

[0097] In step 505, the space-time polarization adaptive processing weight vector calculated in step 504 is applied to the echo data of each Doppler channel to obtain processed output data.

[0098] In step 501, pulse-Doppler processing is performed on the echo element-pulse domain data of the horizontal and vertical polarization channels respectively, which specifically includes:

[0099] Assume that before PD treatment l The echo signal data of the H channel of the range unit is , the echo signal data of the V channel is The spatial frequency of the main lobe pointing direction is , and its spatial steering vector is . Set k The normalized Doppler center frequency of the Doppler channel is , and its time domain steering vector is .

[0100] After PD treatment, l In the distance unit k The H channel echo data of a Doppler channel is:

[0101] (1)

[0102] No. l In the distance unit k The V channel echo data of a Doppler channel is:

[0103] (2)

[0104] in, represents the Hadamard product, represents the time domain cone weight vector, represents the spatial cone elimination weight vector. l In the distance unit k The polarization dual-channel data of a Doppler channel can be expressed as:

[0105] (3)

[0106] In step 502, estimating interference or clutter normalized Stokes subvectors of each Doppler channel from the element-Doppler domain echo data of the horizontal and vertical polarization channels obtained in step 501 specifically includes:

[0107] According to the polarization dual-channel data calculated in step 501, l The distance k The polarization coherence vector of a Doppler channel can be expressed as:

[0108] (4)

[0109] in represents the complex conjugate. Further, l In the distance unit k The Stokes vector of the echo signal of the Doppler channel The expression is:

[0110] (5)

[0111] in, In the echo signal, the noise suppresses the interference because its power is much greater than the target signal power and is distributed in all Doppler channels. Therefore, in the clutter clear area, it can be considered that equation (5) estimates the Stokes vector of the interference, and in the clutter area, equation (5) estimates the Stokes vector of the mixed signal of clutter and interference.

[0112] No. l In the distance unit k The echo power of each Doppler channel is , then the Stokes vector can be expressed as ,in for Sub-vector of represents the normalized Stokes subvector. In order to reduce the influence of echo noise on the polarization estimation of the interference signal, l Distance unit before and after LThe adjacent distance units are used as training samples. L The normalized Stokes subvectors of the training samples are averaged as the normalized Stokes subvector of the interference signal in the distance unit. , the mathematical expression is:

[0113] (6)

[0114] In step 503, the target polarization space-time steering vector of each Doppler channel is determined by the interference or clutter normalized Stokes subvector obtained in step 502, which specifically includes:

[0115] Set up l In the distance unit k The optimal polarization filter Stokes vector for a Doppler channel is In order to minimize the interference signal power after processing, it is necessary and Orthogonal in the polarization domain, we have:

[0116] (7)

[0117] in, For the l In the distance unit k The target normalized Stokes subvector of each Doppler channel, diag{} represents a diagonal matrix.

[0118] Will The conversion to Jones vector is the target polarization steering vector, which is expressed as:

[0119] (8)

[0120] in For the l In the distance unit k The polarization ratio of the Doppler channel.

[0121] In step 504, the space-time polarization adaptive processing weight vector is calculated using the target polarization space-time steering vector obtained in step 503 and the estimated echo space-time polarization covariance matrix, which specifically includes:

[0122] No. l In the distance unit k The target space-time polarization steering estimation vector of a Doppler channel is:

[0123] (9)

[0124] Using the adjacent The space-time covariance matrix of the polarization dual-channel clutter noise estimated by the range unit can be expressed as:

[0125] (10)

[0126] in The value of should not be less than 2 times the system degrees of freedom.

[0127] According to the linear constrained minimum variance criterion, l In the distance unit k The weight vector of the space-time polarization joint processing of the Doppler channels can be expressed as:

[0128] (11)

[0129] In step 505, the space-time polarization adaptive processing weight vector calculated in step 504 is applied to the echo data of each Doppler channel to obtain processed output data, which specifically includes: performing space-time polarization joint processing on the space-time polarization dual channel data, while suppressing interference and clutter signals, and obtaining the first l Distance unit k The output of each Doppler channel is:

[0130] (12)

[0131] This embodiment uses a space-time polarization joint processing method to achieve simultaneous suppression of main lobe clutter and noise suppression main lobe interference, specifically: first, pulse-Doppler processing is performed on the echo array element-pulse domain data of the horizontal and vertical polarization channels respectively, and then the interference or clutter normalized Stokes subvectors of each Doppler channel are estimated according to the array element-Doppler domain echo data of the horizontal and vertical polarization channels, and the target polarization space-time steering vector of each Doppler channel is determined according to the echo polarization Stokes vector, and finally the space-time polarization adaptive processing weight vector is calculated using the estimated echo space-time polarization covariance matrix and the target polarization space-time steering vector, and space-time polarization joint processing is performed, so as to achieve simultaneous suppression of main lobe clutter and noise suppression main lobe interference. Compared with the traditional adaptive polarization cancellation method, the present invention can more effectively suppress main lobe clutter while suppressing main lobe interference, thereby improving the detection probability of target signals.

[0132] Embodiment 3:

[0133] like Figure 6 , is a schematic diagram of the architecture of a main lobe clutter and interference suppression device based on space-time polarization adaptive processing according to an embodiment of the present invention. The main lobe clutter and interference suppression device based on space-time polarization adaptive processing according to this embodiment includes one or more processors 21 and a memory 22. Figure 6 A processor 21 is taken as an example.

[0134] The processor 21 and the memory 22 may be connected via a bus or other means. Figure 6 The example of connecting through bus is taken in the following.

[0135] The memory 22, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs and non-volatile computer executable programs, such as the main lobe clutter and interference suppression method based on space-time polarization adaptive processing in Example 1. The processor 21 executes the main lobe clutter and interference suppression method based on space-time polarization adaptive processing by running the non-volatile software programs and instructions stored in the memory 22.

[0136] The memory 22 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some embodiments, the memory 22 may optionally include a memory remotely arranged relative to the processor 21, and these remote memories may be connected to the processor 21 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0137] The program instructions / modules are stored in the memory 22, and when executed by the one or more processors 21, the main lobe clutter and interference suppression method based on space-time polarization adaptive processing in the above-mentioned embodiment 1 is executed.

[0138] It is worth noting that the information interaction, execution process, etc. between the modules and units within the above-mentioned devices and systems are based on the same concept as the processing method embodiment of the present invention. The specific contents can be found in the description of the method embodiment of the present invention and will not be repeated here.

[0139] A person skilled in the art may understand that all or part of the steps in the various methods of the embodiments may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, and the storage medium may include: a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, etc.

[0140] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A main lobe clutter and interference suppression method based on space-time polarization adaptive processing, characterized in that: include: According to the echo element-pulse domain data of the horizontal polarization channel and the echo element-pulse domain data of the vertical polarization channel, polarization dual-channel element-Doppler domain echo data are constructed; Calculating interference or clutter normalized Stokes subvectors of each Doppler channel according to the polarized dual-channel array element-Doppler domain echo data; Determining the target polarization space-time steering vector of each Doppler channel according to the interference or clutter normalized Stokes subvector; Calculate the space-time polarization joint processing weight vector using the target polarization space-time steering vector and the echo space-time polarization covariance matrix; Applying the space-time polarization joint processing weight vector to the echo data of each Doppler channel to obtain processed output data; Determining the target polarization space-time steering vector of each Doppler channel according to the interference or clutter normalized Stokes subvector specifically includes: In order to minimize the interference signal power after processing, and Orthogonal in the polarization domain, that is, ;in, For the l In the distance unit k The normalized Stokes subvector of interference or clutter in a Doppler channel, For the l In the distance unit k The target normalized Stokes subvector of a Doppler channel, diag{} represents a diagonal matrix; Will Convert to Jones vector and get l In the distance unit k The target polarization space-time steering vector of the Doppler channel ;in, For the l In the distance unit k The optimal polarization-filtered Stokes vector for a Doppler channel, ; For the l In the distance unit k The polarization ratio of the Doppler channel, .

2. The main lobe clutter and interference suppression method based on space-time polarization adaptive processing according to claim 1, characterized in that: The step of constructing polarization dual-channel element-Doppler domain echo data according to the echo element-pulse domain data of the horizontal polarization channel and the echo element-pulse domain data of the vertical polarization channel specifically includes: For l Echo array element-pulse domain data of a range unit in the horizontal polarization channel Pulse-Doppler processing is performed to obtain l In the distance unit k Horizontally polarized channel array element of a Doppler channel - Doppler domain echo data ; For l Echo array element-pulse domain data of a range unit in the vertical polarization channel Pulse-Doppler processing is performed to obtain l In the distance unit k Doppler channel vertical polarization channel array element - Doppler domain echo data ; Use the l In the distance unit k Horizontally polarized channel array element of a Doppler channel - Doppler domain echo data and l In the distance unit k Doppler channel vertical polarization channel array element - Doppler domain echo data , construct the l In the distance unit k Polarization dual-channel array element-Doppler domain echo data of Doppler channels .

3. The main lobe clutter and interference suppression method based on space-time polarization adaptive processing according to claim 2 is characterized in that: The said l In the distance unit k Horizontally polarized channel array element of a Doppler channel - Doppler domain echo data ; in, represents the Hadamard product, represents the time domain cone weight vector, represents the airspace cone elimination weight vector, For the k The time-domain steering vector of each Doppler channel, , For the k The normalized Doppler center frequency of the Doppler channel, K is the number of pulses emitted by the radar in one pulse repetition period; is the target airspace guidance vector, and its mathematical expression is , the spatial frequency of the main lobe pointing direction is , N is the number of sub-arrays.

4. The main lobe clutter and interference suppression method based on space-time polarization adaptive processing according to claim 2, characterized in that: The said l In the distance unit k Doppler channel vertical polarization channel array element - Doppler domain echo data ; in, represents the Hadamard product, represents the time domain cone weight vector, represents the airspace cone elimination weight vector, For the k The time-domain steering vector of each Doppler channel, K is the number of pulses emitted by the radar in one pulse repetition period; is the target airspace guidance vector, and its mathematical expression is , the spatial frequency of the main lobe pointing direction is , N is the number of sub-arrays.

5. The main lobe clutter and interference suppression method based on space-time polarization adaptive processing according to claim 1, characterized in that: The calculating of the interference or clutter normalized Stokes subvector of each Doppler channel according to the polarized dual-channel array element-Doppler domain echo data specifically includes: Calculate the l The distance k The polarization coherence vector of the Doppler channel ;in, For the l In the distance unit k Polarization dual-channel array element-Doppler domain echo data of Doppler channels, represents the complex conjugate, represents the Hadamard product; Calculate the l In the distance unit k The Stokes vector of the echo signal of the Doppler channel ;in, ; No. l In the distance unit k The Stokes vector of the echo signal of the Doppler channel Also expressed as , calculate the l Stokes subvector normalized by distance units ;in, for The sub-vector of ; For the l In the distance unit k The echo power of each Doppler channel; In the l Distance unit before and after L The adjacent distance unit is taken as the l training samples of distance units, l The normalized Stokes subvectors of the training samples of the distance units are averaged and the average value is used as the l In the distance unit k The normalized Stokes subvector of interference or clutter in a Doppler channel .

6. The main lobe clutter and interference suppression method based on space-time polarization adaptive processing according to claim 5, characterized in that: In a clutter clear area, the interference or clutter normalized Stokes subvector is a normalized Stokes subvector of the interference; In the clutter region, the interference or clutter normalized Stokes subvector is a normalized Stokes subvector of a mixed signal of clutter and interference.

7. The main lobe clutter and interference suppression method based on space-time polarization adaptive processing according to claim 1, characterized in that: The step of calculating a space-time polarization joint processing weight vector by using the target polarization space-time steering vector and the echo space-time polarization covariance matrix specifically includes: Calculate the l In the distance unit k The target space-time polarization steering estimation vector of the Doppler channel ;in, For the l In the distance unit k The target polarization space-time steering vector of the Doppler channel, For the k The time-domain steering vector of each Doppler channel, For the l The spatial steering vector of the main lobe pointing direction of each range unit, , For the l The spatial frequency of the main lobe pointing direction of each range unit; Calculate the l In the distance unit k The weight vector of space-time-polarization joint processing of Doppler channels ;in, is the echo space-time polarization covariance matrix.

8. The main lobe clutter and interference suppression method based on space-time polarization adaptive processing according to claim 7, characterized in that: The echo space-time polarization covariance matrix It is to use the adjacent The distance unit is calculated, specifically: ;in, For the l Array element-pulse domain echo data of range units, Not less than 2 times the system degrees of freedom.

9. The main lobe clutter and interference suppression method based on space-time polarization adaptive processing according to any one of claims 1 to 8, characterized in that: The step of applying the space-time polarization joint processing weight vector to the echo data of each Doppler channel to obtain processed output data specifically includes: Use l In the distance unit k The weight vector of the space-time polarization joint processing of the Doppler channels is l Distance unit k The echo data of the Doppler channels are processed jointly in space and time to obtain the l Distance unit k The processed output data of each Doppler channel ;in, For the l Array element-pulse domain echo data of range units, For the l In the distance unit k The weight vector for the joint space-time and polarization processing of the Doppler channels.

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