CN114740470A - Microwave wavefront modulation foresight imaging method and device based on attribute scattering model - Google Patents

Microwave wavefront modulation foresight imaging method and device based on attribute scattering model Download PDF

Info

Publication number
CN114740470A
CN114740470A CN202210278657.9A CN202210278657A CN114740470A CN 114740470 A CN114740470 A CN 114740470A CN 202210278657 A CN202210278657 A CN 202210278657A CN 114740470 A CN114740470 A CN 114740470A
Authority
CN
China
Prior art keywords
reference matrix
target
scattering model
model reference
scattering
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210278657.9A
Other languages
Chinese (zh)
Inventor
程永强
刘清萍
曹凯程
刘康
王宏强
刘红彦
黎湘
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
National University of Defense Technology
Original Assignee
National University of Defense Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by National University of Defense Technology filed Critical National University of Defense Technology
Priority to CN202210278657.9A priority Critical patent/CN114740470A/en
Publication of CN114740470A publication Critical patent/CN114740470A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
    • G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
    • G01S13/904—SAR modes
    • G01S13/9043—Forward-looking SAR

Landscapes

  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

The application relates to a microwave wavefront modulation foresight imaging method and device based on an attribute scattering model. The method comprises the following steps: random frequency hopping modulation is carried out on the wave front of the microwave transmitted by the array elements in the radar array, a space-time two-dimensional uncorrelated radiation field of an imaging plane is constructed according to the obtained microwave signals transmitted by the radar array, discretization is carried out on the imaging plane to obtain a discretization grid, obtaining a point scattering model reference matrix corresponding to an imaging plane according to the microwave signal and the reference signal of the center point of the discretization grid, respectively performing one-dimensional and two-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix and a surface scattering model reference matrix, and then, an imaging equation based on the scattering attribute model is established and solved, and compared with a microwave wavefront modulation foresight imaging method for approximating the target to a discrete point scattering model, the microwave wavefront modulation foresight imaging based on the attribute scattering model can better realize the reconstruction of the line and surface structure of the target and better restore the geometric structure information of the target.

Description

Microwave wavefront modulation foresight imaging method and device based on attribute scattering model
Technical Field
The application relates to the technical field of microwave imaging, in particular to a microwave wavefront modulation foresight imaging method and device based on an attribute scattering model.
Background
The existing high-resolution imaging radar such as a synthetic aperture radar and an inverse synthetic aperture radar mainly works in side-looking and oblique-looking imaging modes, and a forward-looking imaging blind area exists. The microwave wavefront modulation forward-looking imaging technology is a high-resolution staring imaging technology by using the classic optical correlation imaging principle for reference. The microwave wavefront modulation forward-looking imaging technology does not depend on the relative motion of a target and a radar system, so the forward-looking microwave wavefront modulation forward-looking imaging technology has great application potential in a forward-looking imaging scene, and is expected to form complementation with a synthetic aperture and an inverse synthetic aperture high-resolution radar imaging technology.
The classic microwave wavefront modulation imaging model is established on the basis that the scattering characteristics of a target can be well approximated to the superposition of discrete point scattering models, but under the assumption of the point scattering models, the microwave wavefront modulation forward-looking imaging technology can only reconstruct a plurality of strong scattering points of the target, but cannot reconstruct geometric structures such as lines, surfaces and the like of the target.
Disclosure of Invention
Based on the foregoing, there is a need to provide a method and an apparatus for attribute-based scattering model forward-looking microwave wavefront modulation imaging, which can effectively reconstruct radar images containing target points, lines and surface geometries.
A microwave wavefront modulation look-ahead imaging method based on an attribute scattering model, the method comprising:
constructing a radar array; the radar array comprises a plurality of array elements;
random frequency hopping modulation is carried out on the wave front of the array element transmitting microwaves to obtain microwave signals transmitted by the radar array, and a space-time two-dimensional uncorrelated radiation field of a target imaging plane is constructed according to the microwave signals;
discretizing the imaging plane to obtain a discretization grid, obtaining a point scattering model reference matrix corresponding to the imaging plane according to the microwave signal and a reference signal of a central point of the discretization grid, and performing one-dimensional integration and two-dimensional integration on the point scattering model reference matrix respectively to obtain a line scattering model reference matrix and a surface scattering model reference matrix;
obtaining a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field, obtaining an imaging equation of a target according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, and solving the imaging equation to perform target imaging.
In one embodiment, the obtaining of the microwave signal transmitted by the radar array by performing random frequency hopping modulation on the wavefront of the microwave transmitted by the array element includes:
random frequency hopping modulation is carried out on the transmitted microwave wavefront of the radar array, and the obtained microwave signals transmitted by the radar array are as follows:
Figure BDA0003557151610000021
wherein A is the amplitude of the microwave signal, fcIs the carrier frequency, fn,mThe frequency of the signal is transmitted for the mth frequency hopping of the nth array element,
Figure BDA0003557151610000022
and transmitting the initial phase of the signal for the nth array element.
In one embodiment, the obtaining a point scattering model reference matrix corresponding to an imaging plane according to the microwave signal and a reference signal of a central point of the discretization grid includes:
obtaining a point scattering model reference matrix corresponding to an imaging plane according to the microwave signal and the reference signal of the central point of the discretization grid as follows:
Figure BDA0003557151610000023
wherein c is the propagation velocity of the microwave, RnIs the distance between the nth array element and the center of the imaging plane, thetanIs the azimuth angle of the nth array element, phinIs the pitch angle of the nth array element, (x)i,yi) Coordinates of the scattering target at the ith point.
In one embodiment, performing one-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix includes:
performing one-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix as follows:
Figure BDA0003557151610000031
wherein (x)l0,yl0) As line target center coordinates, LlIn order to be the length of the line object,
Figure BDA0003557151610000032
as a line target angle, DlFor the integration region, j denotes the jth line target.
In one embodiment, performing two-dimensional integration on the point scattering model reference matrix to obtain a surface scattering model reference matrix includes:
performing two-dimensional integration on the point scattering model reference matrix to obtain a surface scattering model reference matrix as follows:
Figure BDA0003557151610000033
wherein (x)r0,yr0) Is the center coordinate of the face target, LrIs the center length of the face target, HrThe width of the target of the face is,
Figure BDA0003557151610000034
is made of flourTarget angle, k denotes the k-th line target.
In one embodiment, the obtaining a target scattered echo vector of an array element in a radar array according to a space-time two-dimensional uncorrelated radiation field, and obtaining an imaging equation of a target according to the target scattered echo vector, the point scattering model reference matrix, the line scattering model reference matrix, and the surface scattering model reference matrix includes:
obtaining a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field as follows:
SR＝[SR(1),SR(2),...,SR(M)]T
obtaining an imaging equation of the target according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, wherein the imaging equation is as follows:
SR＝Sp·σp+Sl·σl+Sr·σr+n
wherein S ispFor point-scatter model reference matrices, SlIs a reference matrix of a line scattering model, SrIs a reference matrix of a surface scattering model,
Figure BDA0003557151610000041
for point target scattering coefficients of the point scattering model reference matrix to be solved,
Figure BDA0003557151610000042
for the line object scattering coefficients of the line scattering model reference matrix to be solved,
Figure BDA0003557151610000043
and n is Gaussian white noise, and is the surface target scattering coefficient of the reference matrix of the surface scattering model to be solved.
In one embodiment, solving the imaging equation for imaging the object comprises:
converting the imaging equation to obtain an objective function as follows:
Figure BDA0003557151610000044
wherein λ ispRegularization coefficients, λ, of point target scattering coefficients for a point scattering model reference matrix to be solvedlRegularization coefficients, λ, of the line object scattering coefficients for the line scattering model reference matrix to be solvedrAnd the regularization parameters of the surface target scattering coefficients of the surface scattering reference matrix to be solved.
And solving the objective function by adopting an alternating direction multiplier method to carry out target imaging.
A microwave wavefront modulation lookahead imaging apparatus based on an attribute scattering model, the apparatus comprising:
the array construction module is used for constructing a radar array; the radar array comprises a plurality of array elements;
the radiation field construction module is used for carrying out random frequency hopping modulation on the wave front of the microwave transmitted by the array element to obtain a microwave signal transmitted by the radar array and constructing a space-time two-dimensional uncorrelated radiation field of a target imaging plane according to the microwave signal;
the reference matrix construction module is used for discretizing the imaging plane to obtain a discretization grid, obtaining a point scattering model reference matrix corresponding to the imaging plane according to the microwave signal and a reference signal of a central point of the discretization grid, and respectively performing one-dimensional integration and two-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix and a surface scattering model reference matrix;
and the imaging module is used for obtaining a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field, obtaining an imaging equation of a target according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, solving the imaging equation and imaging the target.
A computer device comprising a memory and a processor, the memory storing a computer program, the processor implementing the following steps when executing the computer program:
constructing a radar array; the radar array comprises a plurality of array elements;
random frequency hopping modulation is carried out on the wave front of the array element transmitting microwaves to obtain microwave signals transmitted by the radar array, and a space-time two-dimensional uncorrelated radiation field of a target imaging plane is constructed according to the microwave signals;
discretizing the imaging plane to obtain a discretization grid, obtaining a point scattering model reference matrix corresponding to the imaging plane according to the microwave signal and a reference signal of a central point of the discretization grid, and performing one-dimensional integration and two-dimensional integration on the point scattering model reference matrix respectively to obtain a line scattering model reference matrix and a surface scattering model reference matrix;
obtaining a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field, obtaining an imaging equation of a target according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, and solving the imaging equation to perform target imaging.
A computer-readable storage medium, on which a computer program is stored which, when executed by a processor, carries out the steps of:
constructing a radar array; the radar array comprises a plurality of array elements;
random frequency hopping modulation is carried out on the wave front of the array element transmitting microwaves to obtain microwave signals transmitted by the radar array, and a space-time two-dimensional uncorrelated radiation field of a target imaging plane is constructed according to the microwave signals;
discretizing the imaging plane to obtain a discretization grid, obtaining a point scattering model reference matrix corresponding to the imaging plane according to the microwave signal and a reference signal of a central point of the discretization grid, and performing one-dimensional integration and two-dimensional integration on the point scattering model reference matrix respectively to obtain a line scattering model reference matrix and a surface scattering model reference matrix;
obtaining a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field, obtaining an imaging equation of a target according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, and solving the imaging equation to perform target imaging.
The microwave wavefront modulation foresight imaging method and device based on the attribute scattering model are characterized in that random frequency hopping modulation is carried out on wavefronts of microwaves emitted by array elements in a radar array to obtain microwave signals emitted by the radar array, a space-time two-dimensional uncorrelated radiation field of a target imaging plane is constructed according to the microwave signals, the difference of the radiation field provides abundant information to realize the resolution of a target, the imaging plane is discretized to obtain a discretized grid, a point scattering model reference matrix corresponding to the imaging plane is obtained according to the microwave signals and reference signals of the central point of the discretized grid, one-dimensional integration and two-dimensional integration are respectively carried out on the point scattering model reference matrix to obtain a line scattering model reference matrix and a scattering model reference matrix, then an imaging equation based on the scattering attribute model is established and solved, and the radar image of the target can be obtained by carrying out correlation processing on reference signals of echoes and the radiation field, compared with a microwave wavefront modulation foresight imaging method for approximating the target to a discrete point scattering model, the microwave wavefront modulation foresight imaging based on the attribute scattering model can better realize the reconstruction of the line and surface structure of the target and better restore the geometric structure information of the target.
Drawings
FIG. 1 is a diagram of an application scenario of a microwave wavefront modulation foresight imaging method based on an attribute scattering model in an embodiment;
FIG. 2 is a schematic diagram of a microwave wavefront modulation forward-view imaging method based on a point scattering model in one embodiment;
FIG. 3 is simulation comparison results in one embodiment;
FIG. 4 is a comparison result of simulation in another embodiment;
FIG. 5 is a block diagram illustrating a microwave wavefront modulation front-view imaging device based on an attribute scattering model according to an embodiment;
FIG. 6 is a diagram of the internal structure of a computer device in one embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
In one embodiment, as shown in fig. 1, there is provided a microwave wavefront modulation foresight imaging method based on an attribute scattering model, comprising the following steps:
step 102, constructing a radar array.
The radar array comprises a plurality of array elements, wherein the array elements can be divided into transmitting array elements and receiving array elements, and self-receiving array elements can be adopted.
And 104, performing random frequency hopping modulation on the wave front of the microwave transmitted by the array element to obtain a microwave signal transmitted by the radar array, and constructing a space-time two-dimensional uncorrelated radiation field of the target imaging plane according to the microwave signal.
The method comprises the steps of modulating the wave front of the electromagnetic wave, constructing a space-time irrelevant radiation field, and performing correlation processing on a reference signal of a target scattering echo and the radiation field after the radiation field interacts with a detected target to obtain a radar image of the target.
And 106, discretizing the imaging plane to obtain a discretization grid, obtaining a point scattering model reference matrix corresponding to the imaging plane according to the microwave signal and the reference signal of the central point of the discretization grid, and performing one-dimensional integration and two-dimensional integration on the point scattering model reference matrix respectively to obtain a line scattering model reference matrix and a surface scattering model reference matrix.
In the microwave wavefront modulation foresight imaging technology, an imaging region is divided into a plurality of discrete grid points, imaging quality can be further improved by converting an imaging problem into a parametric solving problem, but the method is different from the classical wavefront modulation foresight imaging technology in that a target is simply divided into discrete point scattering centers.
And 108, obtaining a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field, obtaining an imaging equation of the target according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, solving the imaging equation, and imaging the target.
Through the constructed reference matrixes of the point scattering model, the line scattering model and the surface scattering model, an imaging equation based on the scattering attribute model is established and solved, and the radar image containing the point, line and surface geometrical structures of the target can be effectively reconstructed.
In the microwave wavefront modulation foresight imaging method based on the attribute scattering model, the microwave wavefront modulation foresight imaging method and the device based on the attribute scattering model obtain microwave signals transmitted by a radar array by randomly hopping the wavefronts of microwaves transmitted by array elements in the radar array, construct a space-time two-dimensional uncorrelated radiation field of a target imaging plane according to the microwave signals, the difference of the radiation field provides abundant information for realizing the resolution of the target, discretize the imaging plane to obtain a discretization grid, obtain a point scattering model reference matrix corresponding to the imaging plane according to the microwave signals and reference signals of the central point of the discretization grid, respectively perform one-dimensional integration and two-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix and a surface scattering model reference matrix, then establish an imaging equation based on the scattering attribute model and solve the imaging equation, the radar image of the target can be obtained by performing correlation processing on the reference signals of the echo and the radiation field, and compared with a microwave correlation imaging method for approximating the target to a discrete point scattering model, the microwave wavefront modulation imaging based on the attribute scattering model can better realize reconstruction of a line and surface structure of the target and better restore the geometric structure information of the target.
Specifically, the method for obtaining the microwave signal transmitted by the radar array by performing random frequency hopping modulation on the wavefront of the microwave transmitted by the array element includes:
random frequency hopping modulation is carried out on the transmitted microwave wavefront of the radar array, so that microwave signals transmitted by the radar array are obtained, the radar array is arranged to contain N self-transmitting and self-receiving array elements, M random frequency hopping signals are transmitted together, and then the nth array element transmits waveforms at mth frequency hopping:
Figure BDA0003557151610000081
wherein A is the amplitude of the microwave signal, fcIs the carrier frequency, fn,mThe frequency of the signal is transmitted for the mth frequency hopping of the nth array element,
Figure BDA0003557151610000082
and transmitting the initial phase of the signal for the nth array element.
Specifically, obtaining a point scattering model reference matrix corresponding to the imaging plane according to the microwave signal and the reference signal of the central point of the discretization grid includes:
as shown in fig. 2, a schematic diagram of a microwave-correlation imaging method based on a point scattering model is provided, an imaging plane is discretized into I grid cells, and if a scattering point of a target is located at the center of each grid cell in an imaging area, a reference signal of an ith grid is a superposition of all N transmission signals at an mth frequency hopping, that is, a point scattering model reference matrix corresponding to the imaging plane is obtained according to a microwave signal and a reference signal at a central point of a discretization grid as follows:
Figure BDA0003557151610000091
wherein c is the propagation velocity of the microwave, RnIs the distance between the nth array element and the center of the imaging plane, thetanIs the azimuth angle of the nth array element, phinIs the pitch angle of the nth array element, (x)i,yi) Coordinates of the ith point scattering target.
Further, performing one-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix, including:
fig. 3(a) is a parameter schematic diagram of a line scattering model, wherein a scattering response of the line scattering model can be regarded as a one-dimensional integral of a point scattering model response, and the point scattering model reference matrix is subjected to one-dimensional integral to obtain a line scattering model reference matrix as follows:
Figure BDA0003557151610000092
wherein (x)l0,yl0) As line target center coordinates, LlIn order to be the length of the line object,
Figure BDA0003557151610000093
as a line target angle, DlFor the integration region, j denotes the jth line target.
Further, performing two-dimensional integration on the point scattering model reference matrix to obtain a surface scattering model reference matrix, including:
fig. 3(b) is a schematic parameter diagram of a surface scattering model, where the scattering response of the surface scattering model can be regarded as two-dimensional integral of the point scattering model response, and the point scattering model reference matrix is subjected to two-dimensional integral to obtain a reference matrix of the surface scattering model as follows:
Figure BDA0003557151610000101
wherein (x)r0,yr0) Is the center coordinate of the face target, LrIs the center length of the face target, HrThe width of the target of the face is,
Figure BDA0003557151610000102
for the face target angle, k denotes the kth line target.
In one embodiment, obtaining a target scattered echo vector of an array element in a radar array according to a space-time two-dimensional uncorrelated radiation field, and obtaining an imaging equation of a target according to the target scattered echo vector, a point scattering model reference matrix, a line scattering model reference matrix and a surface scattering model reference matrix, comprises:
obtaining a target scattering echo vector of an array element in a radar array according to a space-time two-dimensional uncorrelated radiation field, and if a receiving array element receives M times of target echoes, forming a target scattering echo vector as follows:
SR＝[SR(1),SR(2),...,SR(M)]T
assuming that I point scattering targets, J line scattering targets and K surface scattering targets exist in the imaging region, respectively constructing a reference matrix Sp、Sl、SrAnd according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, obtaining an imaging equation of the target as follows:
SR＝Sp·σp+Sl·σl+Sr·σr+n
wherein S ispFor point-scatter model reference matrices, SlFor a line scattering model reference matrix, SrFor the reference matrix of the surface scattering model,
Figure BDA0003557151610000103
for point target scattering coefficients of the point scattering model reference matrix to be solved,
Figure BDA0003557151610000104
for the line object scattering coefficients of the line scattering model reference matrix to be solved,
Figure BDA0003557151610000105
and n is Gaussian white noise, and is the surface target scattering coefficient of the reference matrix of the surface scattering model to be solved.
In one embodiment, solving an imaging equation for imaging an object comprises:
the imaging equation can be regarded as the solution of the convex optimization problem, and the imaging equation is converted to obtain an objective function as follows:
Figure BDA0003557151610000111
wherein λ ispRegularization coefficients, λ, of point target scattering coefficients for a point scattering model reference matrix to be solvedlRegularization coefficients, λ, of the line object scattering coefficients for the line scattering model reference matrix to be solvedrAnd the regularization parameters of the surface target scattering coefficients of the surface scattering reference matrix to be solved.
And solving the objective function by adopting an alternating direction multiplier method to carry out target reconstruction imaging.
In one embodiment, as shown in FIG. 3, simulation comparison results of the present method with other methods are provided. The method is adopted to randomly hop frequency of the array radar transmission signals, a multi-transmission and multi-reception working mode is adopted, the transmission antenna is a single-row uniform linear array, the number of the transmission array elements is 61, the array azimuth angle range is [ -2 degrees ], the pitch angle is 5 degrees, the transmission signal carrier frequency is 34GHz, the bandwidth is 500MHz, the frequency hopping frequency M is 2000, the target distance is 100M, the imaging area is 4M multiplied by 4M, and the imaging signal-to-noise ratio SNR is 20 dB.
FIGS. 3(a), (b) are object scenes, the objects comprising two ball objects, a cylinder object, and a rectangular plane object; 3(c) and (d) are the results of echo imaging by using a back projection algorithm based on electromagnetic calculation software simulation; 3(e) and (f) are the results of the echo calculated according to the attribute scattering model echo formula in the method, which is imaged by using a back projection algorithm, and the correctness of the target attribute scattering model echo formula can be verified according to the consistency of the imaging results; fig. 3(g) and (h) are results of imaging by using a sparse bayesian learning algorithm based on the point scattering model correlation imaging method, and since SBL assumes that the target scattering coefficient satisfies sparse distribution prior, only discrete groups of strong scattering points are present in the imaging results; fig. 3(i), (j) are the results of imaging by using the alternating iteration multiplier algorithm in the method of the present invention, and it can be seen from the results that the microwave wavefront modulation imaging method based on the attribute scattering model can well reconstruct the structural information of the target.
In one embodiment, as shown in FIG. 4, the present method provides high resolution imaging results.
FIG. 4(a) is a target scene including two spherical targets and two cylindrical targets, the Azimuth distance between the two spheres and the two cylinders is 0.1m, the Azimuth range of the antenna array Azimuth angle Azimuth is [ -1 ° 1 ° ], and FIG. 4(b) is the result of echo imaging by using a back projection algorithm based on electromagnetic calculation software simulation, and due to the limitation of real aperture theoretical resolution, it can be seen that the back projection algorithm cannot distinguish adjacent targets; fig. 4(c) is a microwave correlation imaging result based on a point scattering model, and fig. 4(d) is a microwave wavefront modulation imaging result based on an attribute scattering model.
It should be understood that, although the steps in the flowchart of fig. 1 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in fig. 1 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performance of the sub-steps or stages is not necessarily sequential, but may be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.
In one embodiment, as shown in fig. 5, there is provided a microwave wavefront modulation foresight imaging device based on an attribute scattering model, comprising: array construction module, radiation field construction module, reference matrix construction module and imaging module, wherein:
and the array construction module is used for constructing the radar array.
The radar array comprises a plurality of array elements.
And the radiation field construction module is used for carrying out random frequency hopping modulation on the wave front of the microwave transmitted by the array element to obtain a microwave signal transmitted by the radar array and constructing a space-time two-dimensional uncorrelated radiation field of the target imaging plane according to the microwave signal.
The reference matrix construction module is used for discretizing the imaging plane to obtain a discretization grid, obtaining a point scattering model reference matrix corresponding to the imaging plane according to the microwave signal and a reference signal of a central point of the discretization grid, and respectively performing one-dimensional integration and two-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix and a surface scattering model reference matrix.
And the imaging module is used for obtaining a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field, obtaining an imaging equation of the target according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, solving the imaging equation and imaging the target.
Specifically, the radiation field construction module is further configured to perform random frequency hopping modulation on the transmitted microwave wavefront of the radar array, and obtain a microwave signal transmitted by the radar array as follows:
Figure BDA0003557151610000134
wherein A is the amplitude of the microwave signal, fcIs the carrier frequency, fn,mThe frequency of the signal is transmitted for the mth frequency hopping of the nth array element,
Figure BDA0003557151610000135
and transmitting the initial phase of the signal for the nth array element.
Specifically, the reference matrix construction is further configured to obtain a point scattering model reference matrix corresponding to the imaging plane according to the microwave signal and the reference signal of the central point of the discretization grid as follows:
Figure BDA0003557151610000131
wherein c is the propagation velocity of the microwave, RnIs the distance of the nth array element from the center of the imaging plane, thetanIs the n-thAzimuth angle of array element, phinIs the pitch angle of the nth array element, (x)i,yi) Coordinates of the scattering target at the ith point.
Specifically, the reference matrix construction is further configured to perform one-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix, and includes:
performing one-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix as follows:
Figure BDA0003557151610000132
wherein (x)l0,yl0) As line target center coordinates, LlIn order to be the length of the line object,
Figure BDA0003557151610000133
as a line target angle, DlFor the integration region, j denotes the jth line target.
Specifically, the reference matrix construction is also used for performing two-dimensional integration on the point scattering model reference matrix to obtain a surface scattering model reference matrix as follows:
Figure BDA0003557151610000141
wherein (x)r0,yr0) Is the center coordinate of the face target, LrIs the center length of the face target, HrThe width of the target of the face is,
Figure BDA0003557151610000142
k represents the kth line target for the face target angle.
Specifically, the imaging module is further configured to obtain a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field as:
SR＝[SR(1),SR(2),...,SR(M)]T
according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, obtaining an imaging equation of the target as follows:
SR＝Sp·σp+Sl·σl+Sr·σr+n
wherein S ispIs a point scattering model reference matrix, SlFor a line scattering model reference matrix, SrIn order to be a reference matrix of the surface scattering model,
Figure BDA0003557151610000143
for point target scattering coefficients of the point scattering model reference matrix to be solved,
Figure BDA0003557151610000144
for the line object scattering coefficients of the line scattering model reference matrix to be solved,
Figure BDA0003557151610000145
and n is Gaussian white noise, and is the surface target scattering coefficient of the reference matrix of the surface scattering model to be solved.
Specifically, the imaging module is further configured to convert the imaging equation to obtain an objective function as follows:
Figure BDA0003557151610000146
wherein λ ispRegularization coefficients, λ, of point target scattering coefficients for a point scattering model reference matrix to be solvedlRegularization coefficients, λ, of the line object scattering coefficients for the line scattering model reference matrix to be solvedrAnd the regularization parameters of the surface target scattering coefficients of the surface scattering reference matrix to be solved.
And solving the objective function by adopting an alternating direction multiplier method to carry out target imaging.
For specific definition of the microwave wavefront modulation foresight imaging device based on the attribute scattering model, reference may be made to the above definition of the microwave wavefront modulation foresight imaging method based on the attribute scattering model, and details are not described here. The modules in the microwave wavefront modulation foresight imaging device based on the attribute scattering model can be wholly or partially realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as shown in fig. 6. The computer device comprises a processor, a memory, a network interface, a display screen and an input device which are connected through a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program is executed by a processor to implement a method for microwave wavefront modulation look-ahead imaging based on an attribute scattering model. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, a key, a track ball or a touch pad arranged on the shell of the computer equipment, an external keyboard, a touch pad or a mouse and the like.
Those skilled in the art will appreciate that the architecture shown in fig. 6 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.
In an embodiment, a computer device is provided, comprising a memory storing a computer program and a processor implementing the steps of the method in the above embodiments when the processor executes the computer program.
In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored, which computer program, when being executed by a processor, carries out the steps of the method in the above-mentioned embodiments.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware related to instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above examples only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, and these are all within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A microwave wavefront modulation foresight imaging method based on an attribute scattering model is characterized by comprising the following steps:
constructing a radar array; the radar array comprises a plurality of array elements;
random frequency hopping modulation is carried out on the wave front of the array element transmitting microwaves to obtain microwave signals transmitted by the radar array, and a space-time two-dimensional uncorrelated radiation field of a target imaging plane is constructed according to the microwave signals;
discretizing the imaging plane to obtain a discretization grid, obtaining a point scattering model reference matrix corresponding to the imaging plane according to the microwave signal and a reference signal of a central point of the discretization grid, and performing one-dimensional integration and two-dimensional integration on the point scattering model reference matrix respectively to obtain a line scattering model reference matrix and a surface scattering model reference matrix;
obtaining a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field, obtaining an imaging equation of a target according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, and solving the imaging equation to perform target imaging.
2. The method of claim 1, wherein obtaining the microwave signals transmitted by the radar array by performing random frequency hopping modulation on the wave fronts of the microwaves transmitted by the array elements comprises:
random frequency hopping modulation is carried out on the transmitted microwave wavefront of the radar array, and the obtained microwave signals transmitted by the radar array are as follows:
Figure FDA0003557151600000011
wherein A isAmplitude of microwave signal, fcIs the carrier frequency, fn,mThe frequency of the signal is transmitted for the mth frequency hopping of the nth array element,
Figure FDA0003557151600000012
and transmitting the initial phase of the signal for the nth array element.
3. The method according to claim 2, wherein obtaining a point scattering model reference matrix corresponding to an imaging plane according to the microwave signal and a reference signal of a central point of the discretization grid comprises:
obtaining a point scattering model reference matrix corresponding to an imaging plane according to the microwave signal and the reference signal of the central point of the discretization grid, wherein the point scattering model reference matrix is as follows:
Figure FDA0003557151600000021
wherein c is the propagation velocity of the microwave, RnIs the distance between the nth array element and the center of the imaging plane, thetanIs the azimuth angle of the nth array element, phinIs the pitch angle of the nth array element, (x)i,yi) Coordinates of the ith point scattering target.
4. The method of claim 3, wherein one-dimensional integrating the point scattering model reference matrix to obtain a line scattering model reference matrix comprises:
performing one-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix as follows:
Figure FDA0003557151600000022
wherein (x)l0,yl0) As line target center coordinates, LlThe target length of the line is the target length of the line,
Figure FDA0003557151600000023
as a line target angle, DlFor the integration region, j denotes the jth line target.
5. The method of claim 4, wherein two-dimensionally integrating the point scattering model reference matrix to obtain a surface scattering model reference matrix comprises:
performing two-dimensional integration on the point scattering model reference matrix to obtain a surface scattering model reference matrix as follows:
Figure FDA0003557151600000031
wherein (x)r0,yr0) Is the center coordinate of the face target, LrIs the center length of the face target, HrThe width of the target of the face is,
Figure FDA0003557151600000032
for the face target angle, k denotes the kth line target.
6. The method of claim 5, wherein obtaining a target scattered echo vector of an array element in the radar array from the space-time two-dimensional uncorrelated radiation fields, and obtaining an imaging equation of the target from the target scattered echo vector, the point scattering model reference matrix, the line scattering model reference matrix, and the surface scattering model reference matrix comprises:
obtaining a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field as follows:
SR＝[SR(1),SR(2),...,SR(M)]T
obtaining an imaging equation of the target according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, wherein the imaging equation is as follows:
SR＝Sp·σp+Sl·σl+Sr·σr+n
wherein S ispFor point-scatter model reference matrices, SlFor a line scattering model reference matrix, SrIs a reference matrix of a surface scattering model,
Figure FDA0003557151600000033
for point target scattering coefficients of the point scattering model reference matrix to be solved,
Figure FDA0003557151600000034
for the line object scattering coefficients of the line scattering model reference matrix to be solved,
Figure FDA0003557151600000035
and n is Gaussian white noise, and is the surface target scattering coefficient of the reference matrix of the surface scattering model to be solved.
7. The method of any of claims 1 to 6, wherein solving the imaging equation for imaging the object comprises:
converting the imaging equation to obtain an objective function as follows:
Figure FDA0003557151600000041
wherein λ ispRegularization coefficients, λ, of point target scattering coefficients for a point scattering model reference matrix to be solvedlRegularization coefficients, λ, of the line object scattering coefficients for the line scattering model reference matrix to be solvedrAnd the regularization parameters of the surface target scattering coefficients of the surface scattering reference matrix to be solved.
And solving the objective function by adopting an alternating direction multiplier method to carry out target imaging.
8. A microwave wavefront modulation foresight imaging device based on an attribute scattering model, the device comprising:
the array construction module is used for constructing a radar array; the radar array comprises a plurality of array elements;
the radiation field construction module is used for carrying out random frequency hopping modulation on the wave front of the microwave transmitted by the array element to obtain a microwave signal transmitted by the radar array and constructing a space-time two-dimensional uncorrelated radiation field of a target imaging plane according to the microwave signal;
the reference matrix construction module is used for discretizing the imaging plane to obtain a discretization grid, obtaining a point scattering model reference matrix corresponding to the imaging plane according to the microwave signal and a reference signal of a central point of the discretization grid, and respectively performing one-dimensional integration and two-dimensional integration on the point scattering model reference matrix to obtain a line scattering model reference matrix and a surface scattering model reference matrix;
and the imaging module is used for obtaining a target scattering echo vector of an array element in the radar array according to the space-time two-dimensional uncorrelated radiation field, obtaining an imaging equation of a target according to the target scattering echo vector, the point scattering model reference matrix, the line scattering model reference matrix and the surface scattering model reference matrix, and solving the imaging equation to perform target imaging.
9. A computer device comprising a memory and a processor, the memory storing a computer program, wherein the processor implements the steps of the method of any one of claims 1 to 7 when executing the computer program.
10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 7.
CN202210278657.9A 2022-03-21 2022-03-21 Microwave wavefront modulation foresight imaging method and device based on attribute scattering model Pending CN114740470A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210278657.9A CN114740470A (en) 2022-03-21 2022-03-21 Microwave wavefront modulation foresight imaging method and device based on attribute scattering model

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210278657.9A CN114740470A (en) 2022-03-21 2022-03-21 Microwave wavefront modulation foresight imaging method and device based on attribute scattering model

Publications (1)

Publication Number Publication Date
CN114740470A true CN114740470A (en) 2022-07-12

Family

ID=82276201

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210278657.9A Pending CN114740470A (en) 2022-03-21 2022-03-21 Microwave wavefront modulation foresight imaging method and device based on attribute scattering model

Country Status (1)

Country Link
CN (1) CN114740470A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116660897A (en) * 2023-05-19 2023-08-29 北京建筑大学 SAR microwave visual imaging acquisition method, SAR microwave visual imaging acquisition device and computer equipment

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116660897A (en) * 2023-05-19 2023-08-29 北京建筑大学 SAR microwave visual imaging acquisition method, SAR microwave visual imaging acquisition device and computer equipment
CN116660897B (en) * 2023-05-19 2024-02-27 北京建筑大学 SAR imaging acquisition method and device based on spatial semantics and computer equipment

Similar Documents

Publication Publication Date Title
US9250323B2 (en) Target detection utilizing image array comparison
CN111650585B (en) Near-field millimeter wave sparse MIMO scanning array full-focusing imaging method and device
CN108828593B (en) Random radiation radar correlation imaging method
CN113050089B (en) Fast imaging method and device based on distance attenuation compensation and computer equipment
CN108562897A (en) A kind of sparse imaging method of structure and device of MIMO through-wall radars
CN110609282B (en) Terahertz aperture coding three-dimensional imaging method and device based on back projection
CN107607945B (en) Scanning radar foresight imaging method based on spatial embedding mapping
CN108896990B (en) Building wall imaging method and device by using coupled mode dictionary learning
Shi et al. Improved uniform linear array fitting scheme with increased lower bound on uniform degrees of freedom for DOA estimation
CN111537997B (en) Three-dimensional radar imaging method based on MIMO and compressed sensing technology
CN114740472A (en) Scanning-free single-channel terahertz radar foresight three-dimensional imaging method and system
CN114740470A (en) Microwave wavefront modulation foresight imaging method and device based on attribute scattering model
CN112147608A (en) Rapid Gaussian gridding non-uniform FFT through-wall imaging radar BP method
CN110118956B (en) Bistatic SAR anti-interference performance evaluation method for immune ground jammer area
CN105866756A (en) Staring imaging method of uniform area array emitting radar based on tensor compression perception
CN113109797B (en) Method and device for detecting target of frequency modulation continuous wave staring radar and computer equipment
Wei et al. Learning-based split unfolding framework for 3-D mmW radar sparse imaging
CN111896929B (en) DOD/DOA estimation algorithm of non-uniform MIMO radar
CN114859353B (en) Aperture coding imaging system modeling method and device based on radiation field equivalent measurement
Ricciardi et al. A fast-performing error simulation of wideband radiation patterns for large planar phased arrays with overlapped subarray architecture
CN114740471A (en) Array radar foresight imaging method and device based on echo signal completion
Cao et al. Microwave coincidence imaging based on attributed scattering model
Hu et al. High resolution 3D imaging in MIMO radar with sparse array
CN111722222A (en) Terahertz aperture coding imaging method and device based on antenna array element error compensation
CN112162240A (en) Sparse frequency waveform generation method and device based on co-prime array and storage medium

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination