The content of the invention
For above-mentioned technical problem, it is an object of the invention to provide a kind of microwave relevance imaging thunder based on auxiliary array element
Up to amplitude and phase error correction method, to estimate the amplitude phase error of microwave relevance imaging radar, and then by being mended to amplitude phase error
Repay and obtain ideal space-time radiation field, it is final to utilize relevance imaging algorithm reconstruct image scene.
In order to achieve the above object, the present invention is achieved using following technical scheme.
A kind of microwave relevance imaging radar amplitude and phase error correction method based on auxiliary array element, comprises the following steps:
Step 1, the transmitting antenna array of microwave relevance imaging radar launches a variety of transmitted waveforms, the microwave relevance imaging
The receiving antenna array of radar receives corresponding a variety of echo datas, and matched filtering is carried out to the echo data, and to filtering
Echo data carry out order arrangement afterwards, obtains echo data matrix;Wherein, the receiving antenna array includes rectangular arrangement
Three reception array elements;
Step 2, the invariable rotary that array element obtains the echo data matrix is received according to three at right angles arranged
Characteristic, and the first data selection matrix, the second data selection matrix and the choosing of the 3rd data are constructed according to the invariable rotary characteristic
Matrix is selected, and respectively according to the first data selection matrix, the second data selection matrix and the 3rd data selection matrix to institute
The element stated in echo data matrix is grouped, and obtains corresponding first grouped data, second packet data and the 3rd packet
Data;
Step 3, the auto-covariance matrix of first grouped data, first grouped data and second point are estimated respectively
Cross-covariance, the Cross-covariance of first grouped data and the 3rd grouped data of data are organized, sequential combination is
Data covariance matrix;
Step 4, angle on target estimation is carried out using the data covariance matrix, obtains the direction vector of target;
Step 5, missed according to the direction vector of target range error respectively to the transmitting antenna array and phase
Difference is estimated, obtains the range error estimate and phase error estimation and phase error value of the transmitting antenna array;
Step 6, according to the range error estimate and phase error estimation and phase error value of the transmitting antenna array, respectively to described
The amplitude and phase of transmitting antenna array are corrected.
Preferably, the step 1 includes following sub-step:
1a) transmitting antenna array of microwave relevance imaging radar includes M transmitting array element, the M transmitting array element transmitting
A variety of transmitted waveforms, the complex envelope of the transmitted waveform of m-th of transmitting array element is sm, wherein M is natural number, and m is natural number, and m
=1 ..., M;
1b) receiving antenna array of microwave relevance imaging radar includes N number of reception array element, and N number of reception array element is received
Corresponding a variety of echo datas, the echo data for the q subpulses that n-th of reception array element is received is yN, q, wherein N is nature
Number, n is natural number, and n=1 ..., N, N=3;
1c) by N number of echo data for receiving the q subpulses that array element is received and the hair of described M transmitting array element
The conjugation of the complex envelope of ejected wave shape makees inner product, obtains corresponding matched filtering output xq, wherein xq(n-1) M+m element beRepresent the echo data y of q subpulses for receiving described n-th reception array elementN, qWith m-th of transmitting battle array
The complex envelope s of the transmitted waveform of membermConjugation make after inner product, obtain corresponding matched filtering output,Pass through below equation
Calculating is obtained:
Wherein, n=1 ..., N;M=1 ..., M;Q=1 ..., Q, Q represent pulse number, and M, m, N, n, Q, q are nature
Number;
N number of reception array element corresponding matched filtering output 1d) is lined up one according to subscript m and subscript n order successively
Individual column vector, obtains the matched filtering result x of q subpulsesq;
Array element is received by n-th to press for the matched filtering output result of the complex envelope of the transmitted waveform of M transmitting array element
A column vector is lined up according to subscript m order
WillA column vector x is lined up according to subscript n orderq:
Wherein, operator ()TTransposition computing is represented, oeprator * represents that Khatri-Rao is accumulated, nqFor additive white gaussian
Noise, bqTo obey the target complex scattering coefficients of Swerling II types, ArFor receiving antenna array steering vector, AutTo there is width
Transmitting antenna array steering vector under phase error condition;
1e) the matched filtering result x for respectively obtaining Q pulseqA matrix is lined up according to subscript q orders, is obtained
To the echo data matrix X of Q pulse:
X=[x1..., xQ]=(Ar*Aut)B+W
Wherein, B represents the target scattering coefficient matrix of Q subpulses, B=[b1..., bQ];W represents the additive white of Q subpulses
Noise matrix, W=[n1 ..., nQ]。
Preferably, the step 2 includes following sub-step:
The rotation in the echo data matrix between element 2a) is obtained according to the three reception array elements at right angles arranged
Turn invariant feature, and according to the invariable rotary characteristic construct respectively the first data selection matrix, the second data selection matrix and
3rd data selection matrix, wherein the first data selection matrix is:
Second data selection matrix is:
3rd data selection matrix is:
Wherein, IMThe unit matrix tieed up for M × M,Represent Kronecker products;
It is 2b) right respectively using the first data selection matrix, the second data selection matrix and the 3rd data selection matrix
Element in the echo data matrix X is selected and is grouped, obtain corresponding first grouped data, comprising invariable rotary because
The second packet data of son and the 3rd grouped data comprising the invariable rotary factor, wherein the first grouped data is:
X1=J1X=AutB+J1W
Second packet data are:X2=J2X=AutΛxB+J2W
3rd grouped data is:
X3=J3X=AutΛyB+J3W
Wherein,For the invariable rotary factor relative to x-axis,For the invariable rotary factor relative to y-axis.
Preferably, the step 3 includes following sub-step:
3a) calculated by below equation and obtain the first grouped data X1Autocorrelation matrix R11:
Wherein,B represents the target scattering coefficient matrix of Q subpulses, AutFor in the case of having an amplitude phase error
Transmitting antenna array, σn 2For noise power, Q represents pulse number, IMRepresent M × M unit matrix, operator ()HTable
Show the conjugate transposition of matrix;
3b) by below equation to the first grouped data X1Autocorrelation matrix R11Eigenvalues Decomposition is carried out, noise is obtained
The estimation of power
Wherein, the diagonal matrix Λ that characteristic vector is constitutedr=diag ([λR, 1, λR, 2..., λR, M]), wherein λR, 1≥λR, 2
≥…≥λR, M, UrIt is characterized the matrix of vector composition, operator ()HThe conjugate transposition of representing matrix, Q represents pulse number, M
Represent the element number of array of transmitting antenna array;
3c) by the estimation of noise powerFrom the first grouped data X1Autocorrelation matrix R11It is middle to deduct, obtain first point
Group data X1Auto-covariance matrix R11s:
Wherein,B represents the target scattering coefficient matrix of Q subpulses, AutFor in the case of having an amplitude phase error
Transmitting antenna array,For the estimation of noise power, Q represents pulse number, IMRepresent M × M unit matrix, operator
(·)HThe conjugate transposition of representing matrix;
3d) calculated by below equation and obtain the first grouped data X1With second packet data X2Cross-covariance
R21:
Wherein,B represents the target scattering coefficient matrix of Q subpulses, AutFor in the case of having an amplitude phase error
Transmitting antenna array, Q represents pulse number,For the rotation relative to x-axis
Invariant factor, operator ()HThe conjugate transposition of representing matrix;
3e) calculated by below equation and obtain the first grouped data X1With the 3rd grouped data X3Cross-covariance
R31:
Wherein,B represents the target scattering coefficient matrix of Q subpulses, AutFor in the case of having an amplitude phase error
Transmitting antenna array, Q represents pulse number,For the rotation relative to y-axis
Invariant factor, operator ()HThe conjugate transposition of representing matrix;
3f) by the first grouped data X1Auto-covariance matrix R11s, the first grouped data X1With second packet data
X2Cross-covariance R21, the first grouped data X1With the 3rd grouped data X3Cross-covariance R31Sequential combination is number
According to covariance matrix.
Preferably, the step 4 includes following sub-step:
4a) according to below equation pairDo singular value decomposition:
Wherein, R11sFor the first grouped data X1Auto-covariance matrix, R21For the first grouped data X1With second packet number
According to X2Cross-covariance,To ask pseudo-inverse operation to accord with, Λx=diag ([λX, 1..., λX, P]) constituted for P characteristic value
Diagonal matrix, Uxt=[vXt, 1... vXt, P] it is the matrix that the corresponding characteristic vector of P characteristic value is constituted;
4b) according to below equation to being set forth in p-th of eigenvalue λX, pComputing is carried out, p-th of target is obtained relative to x-axis
Cone angle φX, p:
Wherein, operator ∠ () represents to take multiple angle computing;
4c) according to below equation pairDo singular value decomposition:
Wherein, R31For the first grouped data X1With the 3rd grouped data X3Cross-covariance, R11sFor the first packet count
According to X1Auto-covariance matrix,To ask pseudo-inverse operation to accord with, Λy=diag ([λY, 1..., λY, P]) constituted for P characteristic value
Diagonal matrix, Uyt=[vYt, 1..., vYt, P] it is the matrix that the corresponding characteristic vector of P characteristic value is constituted;
4d) according to below equation to p-th of eigenvalue λY, pOperation, can obtain p-th of target relative to y-axis
Cone angle φY, p:
Wherein, operator ∠ () represents to take multiple angle computing;
The corresponding direction vector r of p-th of target 4e) is calculated according to below equationp:
Wherein φX, pCone angle for p-th of target relative to x-axis, φY, pCone angle for p-th of target relative to y-axis.
Preferably, the step 5 includes following sub-step:
The transmitting steering vector a (r of p-th of target when 5a) calculating error free according to below equationp):
Wherein, rT, 1..., rT, MThe 1st position for launching array element to m-th, operator () are represented respectivelyTRepresent transposition
Computing;
5b) according to below equation to p-th of characteristic vector vXt, pNormalization, obtains the transmitting steering vector a (rp) estimate
Meter
Wherein, vXt, p(1) v is representedXt, pFirst element value;
The range error estimate ρ of m-th of transmitting array element 5c) is calculated according to below equationm:
Wherein,For transmitting steering vector a (rp) estimationM-th of element, operator | | to ask absolute
It is worth symbol;
The phase error estimation and phase error value ψ of m-th of transmitting array element 5d) is calculated according to below equationm:
Wherein,For transmitting steering vector a (rp) estimationM-th of element, aP, mFor transmitting steering vector a
(rp) m-th of element, operator ()*Represent conjugate operation.
The present invention compared with prior art, with advantages below:
First, present invention utilizes each array element transmitting unlike signal of the transmitting antenna array of microwave relevance imaging radar
Feature, by auxiliary array element (three reception array element), three groups of data are obtained in receiving terminal matched filtering, and between three groups of data
With invariable rotary characteristic, the present invention utilizes invariable rotary characteristic from the direction vector of extraction target, and further estimates
The amplitude phase error of microwave relevance imaging radar, then carries out amplitude and phase error correction according to the amplitude phase error that estimation is obtained, it is clear that this
Invention does not need calibration source to participate in that radar array can be carried out amplitude and phase error correction, therefore implements simple, and complexity is low, so that
The efficiency of microwave relevance imaging radar amplitude and phase error correction can be improved.
Second, the present invention has obtained the direction vector of target in step 4, therefore the present invention is realizing amplitude and phase error correction
While can also realize the positioning for target.
3rd, the present invention directly estimates amplitude phase error, therefore the present invention can enter to amplitude phase error from echo data
Row on-line correction, i.e., just can carry out amplitude and phase error correction, it is ensured that microwave relevance imaging under radar working condition to radar
The real-time of radar amplitude and phase error correction.
4th, the present invention is compensated using the amplitude phase error estimated to transmitting antenna array amplitude and phase, can
Amplitude and phase error correction is carried out to transmitting antenna array, multiple waveforms are launched using the transmitting antenna array after correction, can be in sky
Between in form accurate space-time random radiation, so as to ensure the imaging accuracy of microwave relevance imaging radar.
Embodiment
In order to facilitate the understanding of the purposes, features and advantages of the present invention, it is below in conjunction with the accompanying drawings and specific real
Applying mode, the present invention is further detailed explanation.
In order to which preferably the present invention will be described, the geometric configuration first to microwave relevance imaging radar used in the present invention
Illustrate.Reference picture 2, is the schematic diagram of the geometric configuration of microwave relevance imaging radar used in the present invention, and the present invention is based on micro-
The radar system of ripple relevance imaging, including:Array element 1 is received, array element 2 is received, receives array element 3, transmitting antenna array 4, the and of target 5
Signal processor 6.Array element 1 is wherein received, array element 2 is received and receives array element 3 and is referred to as aiding in array element.Produced using transmitting antenna 4
Raw microwave radiation field is irradiated generation echo to target 5, and auxiliary array element receives the echo-signal of target, signal processor 6
The amplitude phase error that echo-signal obtains transmitting antenna array 1 is handled, signal processor 6 is according to obtained amplitude phase error and transmitting day
The transmission signal of linear array 4 calculates space-time random radiation, signal processor 6 using calculating space-time random radiation and connect
The reception signal transacting for receiving array element 1 obtains the imaging of target.It should be noted that above-mentioned reception array element is also referred to as reception antenna.
The reception array element 1, reception array element 2, reception array element 3 and transmitting antenna array 4 are co-located in same single base thunder
Up on platform, a face battle array is collectively formed.
The auxiliary array element, i.e. reception array element 1, reception array element 2 and reception array element 3, they at right angles arrange, i.e., with reception
Array element 1 is that origin sets up rectangular coordinate system, receives array element 2 and is distributed in x-axis positive axis, receives array element 3 and is distributed in y-axis positive axis
On.The spacing d for receiving array element 1 and receiving the spacing between array element 2 and receiving array element 1 and receive between array element 3 is satisfied byWherein λ is the wavelength of carrier wave.Auxiliary array element be special antenna, its magnitude-phase characteristics, it is known that and substantially not with environment because
Element changes.
In Fig. 2, coordinate origin O is set to receive the position of array element 1, receives array element 2 in x-axis positive axis, receives battle array
Member 3 is in y-axis positive axis.The azimuth of p-th of target is θp, the angle of pitch is φp, the cone angle relative to x-axis is φX, p, relatively
In y-axis cone angle be φY, p, wherein (cos φp)2+(cosφX, p)2+(cosφY, p)2=1.Transmitting antenna array is launched for m-th
The positional representation of antenna is rT, m=[xm, ym, 0]T, wherein m=1,2 ... M.
Based on the foregoing explanation to the geometric configuration of microwave relevance imaging radar used in the present invention, with reference to Fig. 1 to this
The microwave relevance imaging radar amplitude and phase error correction method based on auxiliary array element of invention is illustrated.It is described to be based on auxiliary array element
Microwave relevance imaging radar amplitude and phase error correction method can be in fig. 2 signal processor in realize.
Reference picture 1, shows a kind of microwave relevance imaging radar amplitude phase error based on auxiliary array element of the embodiment of the present invention
The flow chart of bearing calibration, the present embodiment specifically may comprise steps of:
Step 1, the transmitting antenna array of microwave relevance imaging radar launches a variety of transmitted waveforms, the microwave relevance imaging
The receiving antenna array of radar receives corresponding a variety of echo datas, and matched filtering is carried out to the echo data, and to filtering
Echo data carry out order arrangement afterwards, obtains echo data matrix;Wherein, the receiving antenna array includes rectangular arrangement
Three reception array elements.
The step 1 includes following sub-step:
1a) transmitting antenna array of microwave relevance imaging radar includes M transmitting array element, the M transmitting array element transmitting
A variety of transmitted waveforms, the complex envelope of the transmitted waveform of m-th of transmitting array element is sm, wherein M is natural number, and m is natural number, and m
=1 ..., M.
It should be noted that the transmitting antenna array 4 described in this step in each transmitting antenna array array element corresponding diagram 2 is wrapped
The transmitting antenna array array element contained.
1b) receiving antenna array of microwave relevance imaging radar includes N number of reception array element, and N number of reception array element is received
Corresponding a variety of echo datas, the echo data for the q subpulses that n-th of reception array element is received is yN, q, wherein N is nature
Number, n is natural number, and n=1 ..., N, N=3.
According to Fig. 2, N takes 3, i.e. microwave relevance imaging radar to include receiving array element 1, receive array element 2 and connect in the present embodiment
Array element 3 is received, and 3 receive array element and at right angles arrange, i.e., set up rectangular coordinate system for origin to receive array element 1, receive 2 points of array element
Cloth receives array element 3 and is distributed in y-axis positive axis in x-axis positive axis.Receive array element 1 and receive array element 2 between spacing and
The spacing d for receiving array element 1 and receiving between array element 3 is satisfied byWherein λ is the wavelength of carrier wave.
According to Fig. 2, using microwave relevance imaging radar mockup, each array element of transmitting antenna array 4 launches different ripples
Shape, the echo data for the q subpulses that n-th of reception array element is received is designated as yN, q。
1c) by N number of echo data for receiving the q subpulses that array element is received and the hair of described M transmitting array element
The conjugation of the complex envelope of ejected wave shape makees inner product, obtains corresponding matched filtering output xq, wherein xq(n-1) M+m element beRepresent the echo data y of q subpulses for receiving described n-th reception array elementN, qWith m-th of transmitting battle array
The complex envelope s of the transmitted waveform of membermConjugation make after inner product, obtain corresponding matched filtering output,Pass through below equation
Calculating is obtained:
Wherein, n=1 ..., N;M=1 ..., M;Q=1 ..., Q, Q represent pulse number, and M, m, N, n, Q, q are nature
Number.
N number of reception array element corresponding matched filtering output 1d) is lined up one according to subscript m and subscript n order successively
Individual column vector, obtains the matched filtering result x of q subpulsesq;
Array element is received by n-th to press for the matched filtering output result of the complex envelope of the transmitted waveform of M transmitting array element
A column vector is lined up according to subscript m order
WillA column vector x is lined up according to subscript n orderq:
Wherein, operator ()TTransposition computing is represented, oeprator * represents that Khatri-Rao is accumulated, nqFor additive white gaussian
Noise, bqTo obey the target complex scattering coefficients of Swerling II types, ArFor receiving antenna array steering vector, AutTo there is width
Transmitting antenna array steering vector under phase error condition.
It should be noted that the present embodiment and the transmitted waveform complex envelope s of m-th of transmitting antenna array array elementmConjugation
Make inner product and carry out matched filtering, i.e.,By yN, qWith the number of echoes after all M transmitted waveform matched filterings
According to lining up a column vector, you can obtain receiving array element n matched filtering resultFurther according to the matching filter of 3 reception array element
Ripple result, which joins end to end, obtains the matched filtering result x of q subpulsesq。
1e) the matched filtering result x for respectively obtaining Q pulseqA matrix is lined up according to subscript q orders, is obtained
To the echo data matrix X of Q pulse:
X=[x1..., xQ]=(Ar*Aut)B+W
Wherein, B represents the target scattering coefficient matrix of Q subpulses, B=[b1..., bQ];W represents the additive white of Q subpulses
Noise matrix, W=[n1..., nQ]。
It should be noted that microwave relevance imaging radar mockup, refers to that radar is received and transmitting antenna is placed on together jointly
In one plane, they are θ relative to the angle of pitch of p-th of targetp, azimuth is φp。
Step 2, the invariable rotary that array element obtains the echo data matrix is received according to three at right angles arranged
Characteristic, and the first data selection matrix, the second data selection matrix and the choosing of the 3rd data are constructed according to the invariable rotary characteristic
Matrix is selected, and respectively according to the first data selection matrix, the second data selection matrix and the 3rd data selection matrix to institute
The element stated in echo data matrix is grouped, and obtains corresponding first grouped data, second packet data and the 3rd packet
Data.
The present embodiment is directed to microwave relevance imaging model, in order to go out the directional information of target from reception extracting data, enters
And the amplitude phase error of transmitting antenna array is estimated, it is necessary to construct data selection matrix.The purpose of design data selection matrix is
Element in echo data matrix is grouped, the invariable rotary factor is formed between different groups of element, and then can extract
Go out the directional information of target.
Step 2 described in the present embodiment includes following sub-step:
The rotation in the echo data matrix between element 2a) is obtained according to the three reception array elements at right angles arranged
Turn invariant feature, and according to the invariable rotary characteristic construct respectively the first data selection matrix, the second data selection matrix and
3rd data selection matrix, wherein the first data selection matrix is:
Second data selection matrix is:
3rd data selection matrix is:
Wherein, IMThe unit matrix tieed up for M × M,Represent Kronecker products;
It is 2b) right respectively using the first data selection matrix, the second data selection matrix and the 3rd data selection matrix
Element in the echo data matrix X is selected and is grouped, obtain corresponding first grouped data, comprising invariable rotary because
The second packet data of son and the 3rd grouped data comprising the invariable rotary factor, wherein the first grouped data is:
X1=J1X=AutB+J1W
Second packet data are:X2=J2X=AutΛxB+J2W
3rd grouped data is:
X3=J3X=AutΛvB+J3W
Wherein,For the invariable rotary factor relative to x-axis,For the invariable rotary factor relative to y-axis.
It should be noted that being done to data X after above-mentioned dimension-reduction treatment, invariable rotary factor Λ just can be obtainedxAnd Λy, profit
The angle information of target just can be extracted from echo with subspace class algorithm, and the extraction of target angle information is not sent out
Penetrate the influence of aerial array amplitude phase error.
Step 3, the auto-covariance matrix of first grouped data, first grouped data and second point are estimated respectively
Cross-covariance, the Cross-covariance of first grouped data and the 3rd grouped data of data are organized, sequential combination is
Data covariance matrix.
Swerling II types are obeyed according to Target scatter section area, i.e., the scattering resonance state of target is between pulse and pulse
It is independent, with reference to the ergodic theorem of grouped data, average statistical is replaced using time average, it is estimated that packet count
According to auto-covariance matrix and Cross-covariance, auto-covariance matrix and Cross-covariance are referred to as number in the present embodiment
According to covariance matrix.
3a) calculated by below equation and obtain the first grouped data X1Autocorrelation matrix R11:
Wherein,B represents the target scattering coefficient matrix of Q subpulses, AutFor in the case of having an amplitude phase error
Transmitting antenna array, σn 2For noise power, Q represents pulse number, IMRepresent M × M unit matrix, operator ()HTable
Show the conjugate transposition of matrix.
It should be noted that the present invention replaces the average statistical in the grouped data using time average, it is grouped
Data X1Autocorrelation matrix R11。
3b) by below equation to the first grouped data X1Autocorrelation matrix R11Eigenvalues Decomposition is carried out, noise is obtained
The estimation of power
Wherein, the diagonal matrix Λ that characteristic vector is constitutedr=diag ([λR, 1, λR, 2..., λR, M]), wherein λR, 1≥λR, 2
≥…≥λR, M, UrIt is characterized the matrix of vector composition, operator ()HThe conjugate transposition of representing matrix, Q represents pulse number, M
Represent the element number of array of transmitting antenna array.
3c) by the estimation of noise powerFrom the first grouped data X1Autocorrelation matrix R11It is middle to deduct, obtain first point
Group data X1Auto-covariance matrix R11s:
Wherein,B represents the target scattering coefficient matrix of Q subpulses, AutFor in the case of having an amplitude phase error
Transmitting antenna array,For the estimation of noise power, Q represents pulse number, IMRepresent M × M unit matrix, operator
(·)HThe conjugate transposition of representing matrix.
3d) calculated by below equation and obtain the first grouped data X1With second packet data X2Cross-covariance
R21:
Wherein,B represents the target scattering coefficient matrix of Q subpulses, AutFor in the case of having an amplitude phase error
Transmitting antenna array, Q represents pulse number,For the rotation relative to x-axis
Invariant factor, operator ()HThe conjugate transposition of representing matrix.
3e) calculated by below equation and obtain the first grouped data X1With the 3rd grouped data X3Cross-covariance
R31:
Wherein,B represents the target scattering coefficient matrix of Q subpulses, AutFor in the case of having an amplitude phase error
Transmitting antenna array, Q represents pulse number,For the rotation relative to y-axis
Invariant factor, operator ()HThe conjugate transposition of representing matrix.
3f) by the first grouped data X1Auto-covariance matrix R11s, the first grouped data X1With second packet data
X2Cross-covariance R21, the first grouped data X1With the 3rd grouped data X3Cross-covariance R31Sequential combination is number
According to covariance matrix.
Step 4, angle on target estimation is carried out using the data covariance matrix, obtains the direction vector of target.
The present embodiment utilizes invariable rotary factor ΛxAnd ΛyThe space angle information of target, the step 4 can be extracted
Including following sub-step:
4a) according to below equation pairDo singular value decomposition:
Wherein, R11sFor the first grouped data X1Auto-covariance matrix, R21For the first grouped data X1With second packet number
According to X2Cross-covariance,To ask pseudo-inverse operation to accord with, Λx=diag ([λX, 1..., λX, P]) constituted for P characteristic value
Diagonal matrix, Uxt=[vXt, 1..., vXt, P] it is the matrix that the corresponding characteristic vector of P characteristic value is constituted.
4b) according to below equation to being set forth in p-th of eigenvalue λX, pComputing is carried out, p-th of target is obtained relative to x-axis
Cone angle φX, p:
Wherein, operator ∠ () represents to take multiple angle computing.
4c) according to below equation pairDo singular value decomposition:
Wherein, R31For the first grouped data X1With the 3rd grouped data X3Cross-covariance, R11sFor the first packet count
According to X1Auto-covariance matrix,To ask pseudo-inverse operation to accord with, Λy=diag ([λY, 1..., λY, P]) constituted for P characteristic value
Diagonal matrix, Uyt=[vYt, 1..., vYt, P] it is the matrix that the corresponding characteristic vector of P characteristic value is constituted.
4d) according to below equation to p-th of eigenvalue λY, pOperation, can obtain p-th of target relative to y-axis
Cone angle φY, p:
Wherein, operator ∠ () represents to take multiple angle computing.
The corresponding direction vector r of p-th of target 4e) is calculated according to below equationp:
Wherein φX, pCone angle for p-th of target relative to x-axis, φY, pCone angle for p-th of target relative to y-axis.
Step 5, missed according to the direction vector of target range error respectively to the transmitting antenna array and phase
Difference is estimated, obtains the range error estimate and phase error estimation and phase error value of the transmitting antenna array.
It should be noted that having obtained characteristic vector U according to abovementioned stepsxtWith the direction vector r of targetp, Ke Yijie
Close the position r of m-th of array element of transmitting antenna arrayT, m=[xm, ym, 0]TEstimate the amplitude phase error of transmitting antenna array.It is described
Amplitude phase error includes range error and phase error.
The step 5 includes following sub-step:
The transmitting steering vector a (r of p-th of target when 5a) calculating error free according to below equationp):
Wherein, rT, 1..., rT, MThe 1st position for launching array element to m-th, operator () are represented respectivelyTRepresent transposition
Computing.
5b) according to below equation to p-th of characteristic vector vXt, pNormalization, obtains the transmitting steering vector a (rp) estimate
Meter
Wherein, vXt, p(1) v is representedXt, pFirst element value.
The range error estimate ρ of m-th of transmitting array element 5c) is calculated according to below equationm:
Wherein,For transmitting steering vector a (rp) estimationM-th of element, operator | | to ask absolute
It is worth symbol.
The phase error estimation and phase error value ψ of m-th of transmitting array element 5d) is calculated according to below equationm:
Wherein,For transmitting steering vector a (rp) estimationM-th of element, aP, mFor transmitting steering vector a
(rp) m-th of element, operator ()*Represent conjugate operation.
Due to having been obtained for the range error ρ of all M array elements of transmitting antenna arraym, m=1,2 ..., M, and phase
Error ψm, m=1,2 ..., M.Therefore more satisfactory space-time can be obtained by carrying out amplitude phase error compensation to transmission channel
Radiation field, and then recover target scene using microwave relevance imaging algorithm.
Step 6, according to the range error estimate and phase error estimation and phase error value of the transmitting antenna array, respectively to described
The amplitude and phase of transmitting antenna array are corrected.
By being compensated for transmitting antenna array amplitude and phase, amplitude phase error can be carried out to transmitting antenna array
Correction, launches multiple waveforms using the transmitting antenna array after correction, can form accurate space-time random radiation in space
, so as to ensure the imaging accuracy of microwave relevance imaging radar.
The effect of the present invention can be further illustrated by following emulation experiment.
One, experimental situations
Reference picture 2, the various parameters used in example of the invention are as shown in table 1:
Parameter name |
Specific value |
Carrier frequency |
8GHz |
Launching antenna array array structure |
Uniform surface battle array, array element spacing half-wavelength |
Transmitting antenna array array number |
9×9 |
Range error |
1dB |
Phase error |
20 degree |
Signal bandwidth |
1GHz |
Search coverage center and the distance of center of antenna |
850m |
Parameter name |
Specific value |
Search coverage size |
200m×200m |
Target is arranged |
9 targets are uniformly arranged in search coverage |
It is spaced between target |
X-axis and y-axis direction are spaced 5m |
Fast umber of beats |
1000 |
Signal to noise ratio |
25dB |
The microwave relevance imaging radar parameter of table 1 is set
Two, emulation contents and result
Under described simulated conditions, tested as follows:
Fig. 3 is the range error comparison diagram of the corresponding true amplitude error of 81 array elements and estimation, and Fig. 4 is 81 array elements pair
The true phase error and the phase error comparison diagram of estimation answered.It can be seen that from Fig. 3 and Fig. 4 result and utilize the present invention's
Microwave relevance imaging radar amplitude and phase error correction method can accurately estimate microwave relevance imaging radar range error and
Phase error.
Fig. 5 is the Real profiles of 9 targets of search coverage.When Fig. 6 is without amplitude phase error compensation is carried out, microwave is utilized
The imaging results that relevance imaging algorithm is obtained;Fig. 7 is to estimate amplitude phase error using this method and amplitude phase error is compensated
Afterwards, the imaging results obtained using microwave relevance imaging algorithm.Comparison diagram 5, Fig. 6 and Fig. 7 can further prove the present invention's
Validity, the i.e. present invention effectively On-line Estimation can go out the amplitude phase error of microwave relevance imaging transmitting radar antenna array, and
And after amplitude phase error compensation is carried out, the imaging performance of microwave relevance imaging radar is restored.
To sum up, the correctness of this simulating, verifying present invention but linear and reliability.
For foregoing each method embodiment, in order to be briefly described, therefore it is all expressed as to a series of combination of actions, but
It is that those skilled in the art should know, the present invention is not limited by described sequence of movement, because according to the present invention, certain
A little steps can be carried out sequentially or simultaneously using other.Secondly, those skilled in the art should also know, be retouched in specification
The embodiment stated belongs to preferred embodiment, and involved action and the module not necessarily present invention are necessary.
Each embodiment in this specification is described by the way of progressive, what each embodiment was stressed be with
Between the difference of other embodiment, each embodiment identical similar part mutually referring to.
The present invention can be described in the general context of computer executable instructions, such as program
Module.Usually, program module includes performing particular task or realizes routine, program, object, the group of particular abstract data type
Part, data structure etc..The present invention can also be put into practice in a distributed computing environment, in these DCEs, by
Remote processing devices connected by communication network perform task.In a distributed computing environment, program module can be with
Positioned at including in the local and remote computer-readable storage medium including storage device.
Finally, in addition it is also necessary to explanation, herein, such as first and second or the like relational terms be used merely to by
One entity or operation make a distinction with another entity or operation, and not necessarily require or imply these entities or operation
Between there is any this actual relation or order.Moreover, term " comprising ", "comprising" or its any other variant meaning
Covering including for nonexcludability, so that process, method, commodity or equipment including a series of key elements not only include that
A little key elements, but also other key elements including being not expressly set out, or also include be this process, method, commodity or
The intrinsic key element of equipment.In the absence of more restrictions, the key element limited by sentence "including a ...", is not arranged
Except also there is other identical element in the process including the key element, method, commodity or equipment.
Above to a kind of microwave relevance imaging radar amplitude and phase error correction side based on auxiliary array element provided by the present invention
Method, is described in detail, and specific case used herein is set forth to the principle and embodiment of the present invention, the above
The explanation of embodiment is only intended to the method and its core concept for helping to understand the present invention;Simultaneously for the general skill of this area
Art personnel, according to the thought of the present invention, will change in specific embodiments and applications, in summary, this
Description should not be construed as limiting the invention.