CN111679277B - Multi-baseline chromatography SAR three-dimensional imaging method based on SBRIM algorithm - Google Patents
Multi-baseline chromatography SAR three-dimensional imaging method based on SBRIM algorithm Download PDFInfo
- Publication number
- CN111679277B CN111679277B CN202010467200.3A CN202010467200A CN111679277B CN 111679277 B CN111679277 B CN 111679277B CN 202010467200 A CN202010467200 A CN 202010467200A CN 111679277 B CN111679277 B CN 111679277B
- Authority
- CN
- China
- Prior art keywords
- sar
- baseline
- initialized
- imaging
- dimensional
- 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.)
- Active
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
- G01S13/9004—SAR image acquisition techniques
-
- 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
- G01S13/9094—Theoretical aspects
-
- 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
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
- G01S7/418—Theoretical aspects
Landscapes
- Engineering & Computer Science (AREA)
- Remote Sensing (AREA)
- Radar, Positioning & Navigation (AREA)
- Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention discloses a multi-baseline chromatography SAR three-dimensional imaging method based on an SBRIM algorithm, which is characterized in that the SBRIM algorithm is introduced into the multi-baseline chromatography SAR three-dimensional imaging, firstly, distance-azimuth two-dimensional SAR imaging is carried out on data obtained by each voyage, then, image registration is carried out on the obtained SAR imaging, and an observation vector is obtained; obtaining a measurement matrix according to a chromatography direction signal measurement model, initializing SBRIM algorithm parameters, and calculating a diagonal matrix; and then estimating a scattering coefficient vector and noise power, and finally judging whether the iteration termination condition is met or not, and reconstructing a height direction signal by finishing the operation until the termination condition is reached to obtain a three-dimensional imaging result. Compared with the traditional sparse reconstruction algorithm, the method has the advantages that the advantages of three-dimensional imaging of the traditional algorithm under sparse aerial distribution can be kept, the number of algorithm parameters is reduced, the chromatographic resolution is improved, the three-dimensional image can be reconstructed under less observation data, and the precision of signal sparse reconstruction is improved.
Description
The technical field is as follows:
the invention belongs to the technical field of radar, and particularly relates to the technical field of three-dimensional imaging in a chromatography synthetic aperture radar.
Technical background:
synthetic Aperture Radar (SAR) is a high-resolution Radar that can acquire two-dimensional high-resolution images of ground targets around the clock and all the day. The traditional SAR imaging technology cannot acquire three-dimensional information of an observation space, and the problems of shielding, space blurring, top-bottom inversion and the like exist in the imaging process, so that three-dimensional imaging becomes an urgent requirement for the development of the SAR imaging technology. The multi-baseline tomography SAR three-dimensional imaging technology is an extension of the traditional two-dimensional SAR imaging technology, and aperture synthesis is carried out on an SAR image sequence acquired by multiple-time flying over in the tomography direction, so that the traditional SAR imaging is extended to the third dimension, the resolution in the tomography direction is obtained, and the three-dimensional imaging of a scene is realized. The multi-baseline chromatography SAR has gained wide attention and application in various fields, and has become a hotspot for researching SAR technologies at home and abroad.
In the tomography SAR imaging processing, in order to realize high-resolution three-dimensional imaging, the acquired data must meet the sampling theorem, however, in practical situations, the number of the navigated is insufficient or non-uniform, and the traditional three-dimensional imaging method is difficult to meet the practical requirements. To address this problem, r.bamler, xx.zhu, a.budillon et al apply a compressive sensing method to tomographic SAR imaging. The current sparse reconstruction algorithms include Orthogonal Matching Pursuit (OMP), Bayesian Compressive Sensing (BCS) imaging algorithm, and the like. The OMP algorithm is widely used due to the advantages of simple structure, low calculation complexity and short operation time, but the OMP algorithm needs to preset sparsity, and needs to carry out approximate estimation of the sparsity in the actual imaging processing, which can cause inaccurate reconstruction result and bring serious reconstruction error; the BCS algorithm selects different prior probability distributions of different observation models, can construct a reconstruction model of a sparse signal more flexibly, and has better estimation performance and flexibility compared with an OMP algorithm, but the BCS algorithm needs to set a plurality of algorithm parameters, and the performance of the BCS algorithm is reduced due to improper selection of the algorithm parameters. Therefore, under less observation data, in order to reconstruct a three-dimensional image and improve the precision of signal sparse reconstruction, the invention provides a multi-baseline chromatography SAR three-dimensional imaging method based on an Iterative minimization Bayesian Iterative reconstruction (SBRIM) algorithm.
The invention content is as follows:
the invention discloses a multi-baseline chromatography SAR three-dimensional imaging method based on an SBRIM algorithm, which is characterized in that the SBRIM algorithm is introduced into the multi-baseline chromatography SAR three-dimensional imaging, firstly, distance-azimuth two-dimensional SAR imaging is carried out on data obtained by each voyage, then, image registration is carried out on the obtained SAR imaging, an observation vector is obtained, then, a measurement matrix is obtained according to a chromatography direction signal measurement model, then, SBRIM algorithm parameters are initialized, an iteration stop condition is set, a diagonal matrix is calculated, then, a scattering coefficient vector is estimated, then, noise power is estimated, finally, whether the iteration stop condition is met or not is judged, and a height direction signal is reconstructed after the operation is finished until the termination condition is reached, so that a three-dimensional imaging result is obtained. The method can reconstruct a three-dimensional image under less observation data, and improve the precision of signal sparse reconstruction.
For the convenience of describing the present invention, the following terms are first defined:
The synthetic aperture radar is a synthetic aperture radar technology which fixes a radar on a load motion platform, combines the motion of the platform to synthesize an equivalent array to realize the resolution in the array direction, and then realizes one-dimensional distance imaging by utilizing the radar beam to delay echoes, thereby realizing two-dimensional imaging of an observed target. See the literature "synthetic aperture radar imaging principle", edited by buzz, electronic technology university press.
Definition 2, vertical baseline and parallel baseline of synthetic aperture radar
The synthetic aperture radar baseline length refers to the distance between two antennas in the synthetic aperture radar system, the vertical baseline refers to the component of the actual baseline which is vertical to the radar sight line in the track method plane, and the parallel baseline refers to the component of the actual baseline which is parallel to the radar sight line in the track method plane. In the invention, the vertical baseline of the synthetic aperture radar system is marked as b⊥Parallel base line is denoted as b||. See the literature "synthetic aperture radar imaging principle", edited by buzz, electronic technology university press.
Definition 3, norm
Let X be a complex fieldUpper linear space, whereinRepresents a complex field if it satisfies the following properties: the | | | X | |, is greater than or equal to 0, and only X | | | 0 when | | X | | |, 0; i | aX | ═ a | | | | | X | |, where a is an arbitrary constant; i X1+X2||≤||X1||+||X2If is called X norm in X space, X is1And X2As any two values in X space. For an N × 1-dimensional discrete signal vector X ═ X1,x2,...,xN]TWhere T is the sign of the transpose operation, L of the vector XPNorm expression isWherein xiFor the ith element of vector X, Σ | represents the sign of the sum of absolute values operation, L of vector X2Norm expression isSee the literature "matrix theory", editions of Huangting, etc., the first edition of higher education publishers, for details.
Definition 4: diagonal matrix
The square matrix with all zero elements except the main diagonal is called diagonal matrixArray, if the main diagonal element is a1,a2,...,anThen the corresponding diagonal matrix is diag { a }1,a2,...,an}. See "matrix theory", Huang Ting Zhu, etc., higher education Press for details.
Definition 5, conjugate transpose
The conjugate transpose is to transpose the complex matrix and take the conjugate, denoted as AHAnd the calculation can be carried out by a standard conjugate transpose method. See "linear algebra", university of peer department of mathematics, higher education press for details.
Definition 6, standard matrix inversion method
Assuming matrix a and matrix B, if AB ═ E, where E is the identity matrix, then matrix B is said to be the right inverse of matrix a, and matrix B is usually written as a-1Calculating the matrix A by a standard matrix inversion method according to the matrix A-1. See "matrix theory", Huang Ting Zhu, etc., higher education Press for details.
Definition 7 and synthetic aperture radar original echo simulation method
The synthetic aperture radar original echo simulation method refers to a method for simulating an original signal with the characteristics of a synthetic aperture radar echo signal under the condition of certain system parameters based on the synthetic aperture radar imaging principle, and is described in the literature, "zhanpeng, synthetic aperture radar echo signal simulation research, thesis of north-west university of industry, 2004".
The purpose of the imaging process is to obtain corresponding point targets from the signal space and distinguish the point targets from adjacent targets, thereby reconstructing a target space corresponding to the scene. The standard two-dimensional SAR imaging method is a process of focusing and imaging an echo data signal of a synthetic aperture radar by using parameters such as a synthetic aperture radar transmitting signal and adopting technologies such as matched filtering. Details are found in the literature "Piyamii, Yangjianyu, Yusheng, etc. the imaging principle of synthetic aperture radar [ M ]. Chengdu, university of electronic science and technology, Press, 2007, 44-65"
Definition 9, compressed sensing sparse reconstruction theory
If a signal is sparse or compressible, the signal can be reconstructed without distortion using a sampling rate well below that required by the nyquist sampling theorem. If the signal is sparse and the measurement matrix satisfies the incoherent and RIP properties, signal sparse reconstruction using compressed sensing recovery can be achieved by solving the following optimization problem:
wherein the content of the first and second substances,is the recovered signal, α is the sparse signal, y is the measurement signal, Θ is the measurement matrix, and ε is the noise threshold. For details, the document "research on sparse imaging technology of array three-dimensional synthetic aperture radar, wecisn, 2013".
An Iterative Minimum sparse Bayesian reconstruction (sparse Bayesian Recovery via Iterative Minimum) imaging algorithm was proposed in 2011 by the assistant professor wecistro of the electronics science university. See the document, "array SAR three-dimensional sparse reconstruction imaging algorithm based on Bayesian estimation, Wecisun, 2011"
The invention provides a multi-baseline chromatography SAR three-dimensional imaging method based on an SBRIM algorithm, which comprises the following steps:
Initializing multi-baseline tomosynthesis SAR system parameters includes: the number of voyage times is marked as N; vertical base line, denoted b⊥nParallel base line, denoted b||nN is 1,2,., N, where N is the number of flights; carrier frequency of radar emission signal fc(ii) a The frequency modulation slope of the radar emission signal is fdr(ii) a The pulse repetition frequency of the radar system is PRF; the bandwidth of the radar emission signal is marked as Br(ii) a The propagation speed of the electromagnetic waves in the air is marked as C; the fast time of the distance is marked as T, T is 1,2, T, T is the total number of the fast time of the distance,the azimuth slow time is recorded as l, wherein l is 1,2, K, and K is the total number of the azimuth slow time; the parameters are all standard parameters of the SAR system and are determined in the design of a multi-baseline chromatography SAR observation scheme; according to the multi-baseline tomographic SAR imaging system scheme and the observation scheme, initialized imaging system parameters required by the SAR imaging method are known.
Step 2: observation scene target space parameter for initializing multi-baseline chromatography SAR
Initializing observation scene target space parameters of the multi-baseline tomography SAR comprises the following steps: taking a space rectangular coordinate system formed by a ground plane of a radar beam irradiation area and a unit vector vertical to the ground plane upwards as an observation scene target space omega of the multi-baseline tomography SAR, wherein omega is Mx×My×MzA pixel; uniformly dividing an observation scene target space omega into three-dimensional unit grids with equal size, called resolution units, and respectively recording the side lengths of the three-dimensional unit grids in the horizontal transverse direction, the horizontal longitudinal direction and the height direction as dx,dyAnd dzThe number of unit grids in the observation scene target space in the horizontal transverse direction, the horizontal longitudinal direction and the height direction is Mx,MyAnd MzThe unit grid size is the traditional theoretical imaging resolution of the multi-baseline chromatography SAR system; a two-dimensional plane imaging space is formed by the horizontal transverse direction and the horizontal longitudinal direction, and the position of the mth element of the tth equidistant stereo unit grid on the two-dimensional plane imaging space is recorded asWherein m is (m)y-1)Mx+mxM is the t-th equidistant solid unit grid height of the two-dimensional plane-dimensional imaging space to the total number of the solid unit grids, and M is Mx·My,mx=1,...,Mx,my=1,...,MyT is the total number of the fast-going moments initialized in step 1.
Recording the scattering coefficient of the mth element of the tth equidistant stereo unit grid in the target space of the observation scene as deltatmM1, 2,., M, T1, 2,., T; using a formulaCalculating to obtain a scattering coefficient matrix, and recording the scattering coefficient matrix as delta, wherein the scattering coefficient matrix delta is composed of M rows and T columns, T is the total number of the distance fast-forward moments obtained by initialization in the step 1, M is the total number of the T-th equidistant stereo unit grid array of the two-dimensional planar imaging space to the stereo unit grid, and M is equal to Mx·My(ii) a According to the SAR imaging method processing scheme of the multi-baseline tomography SAR based on the SBRIM algorithm, the observation scene target space parameters required for initializing the multi-baseline tomography SAR are known.
Step 3, generating original echo data, and performing range-azimuth two-dimensional SAR imaging on each echo data acquired by navigation
The N-th raw echo data of the multi-baseline SAR at the l-th azimuth slow time and the T-th range fast time is denoted as s (T, l, N), T being 1, 2.
Performing distance-direction two-dimensional SAR imaging on the original echo data s (t, l, n) by adopting a standard two-dimensional SAR imaging method in definition 8 to obtain image data of each voyageT is 1,2, T, l is 1,2, T, K, N is 1,2, N, where T is the total number of the distance fast moments initialized in step 1, T is the distance fast moments, K is the total number of the azimuth slow moments initialized in step 1, l is the azimuth slow moments, N is the number of times of flight initialized in step 1, and N is a sequence number of flight.
Step 4, carrying out image registration on the obtained SAR imaging, and carrying out deskew processing to obtain an observation vector
And (2) registering the image sequences acquired by each flight in the step 3 by using a conventional image registration method, so that the same distance-orientation unit corresponds to the same scattering point in the target scene, and obtaining a registered image sequence h (T, l, N), wherein T is 1, 2.
Using a formulaN1, 2, N, calculating the slope distance R of each passing platform from the reference pointn(s) wherein the target position of the chromatographic orientation point is (r)0S) each passing radar platform is in the position of (b)||n,b⊥n). Using a formulaN is 1,2, N, and a deskewed observation signal vector g (t, l, N) is calculated, where h (t, l, N) is a registered image sequence, and R is a registered image sequencen(0) Is a reference point (r)00) a reference slant distance to each navigation radar platform, where T is 1,2,., T, l is 1,2,., K, N is 1,2,., N, where T is a total number of fast-going moments of distances initialized in step 1, T is a total number of fast-going moments of distances, K is a total number of slow-going moments of azimuth initialized in step 1, l is a slow-going moment of azimuth, N is a number of navigation times initialized in step 1, and N is a navigation sequence number.
And 5: constructing an observation vector matrix
Using g ═ g1,g2,...,gN]TConstructing an observation vector matrix, wherein gnG (T, l, N), T1, 2, a, T, l 1,2, a, K, N1, 2, a, N, T being the signal after deskewing in step 4, T being the total number of distance fast times initialized in step 1, T being the total number of distance fast times, K being the total number of azimuth slow times initialized in step 1, l being the azimuth slow time, N being the number of times of flight initialized in step 1, N being each flight number.
Step 6, discretizing a scene target and constructing a measurement matrix
Using the formulaCalculating to obtain the spatial frequency of the nth orbital tomography direction, and recording as xinN is 1,2,. cndot.n; discretizing the position of the scene target in tomography by D uniform points sdD1, 2, D, using the formulaCalculating to obtain a measurement matrix, and recording as phi; wherein the target position of the chromatographic directional point is (r)0,s),b⊥nFor the vertical baseline of the nth track auxiliary image initialized in step 1 with respect to the main image, b||nFor the parallel baseline of the nth track side image initialized in step 1 with respect to the main image, fcC is the propagation speed of the electromagnetic wave initialized in the step 1 in the air.
Step 7, initializing SBRIM algorithm parameters
The initialization parameters of the SBRIM algorithm comprise: a weighting coefficient, noted as α; reconstructing an error threshold, and recording as epsilon; noise power, denoted as β; total number of iterations, denoted Iiter(ii) a The iteration times are marked as k; the smoothing factor is recorded as eta; the diagonal matrix control parameter is marked as p; using a formulaCalculating to obtain an initialized signal estimation valueWherein g is the observation vector matrix in step 5, Φ is the measurement matrix in step 6, and H is the conjugate transpose operator in definition 5.
Updating iteration times, calculating to obtain updated iteration times by adopting a formula k which is k +1, and marking as k; using the formulaCalculating to obtain a diagonal matrix of the kth iteration, and recording the diagonal matrix as Lambda(k). Wherein N is the number of voyages initialized in step 1, p is the diagonal matrix control parameter initialized in step 7, η is the smoothing factor initialized in step 7,for the scattering coefficient estimate for the ith satellite orbit data in the k-1 iteration cycle, diag {. cndot } is the sign of the diagonal matrix operation in definition 4.
Step 9, estimating scattering coefficient vector
Using the formula alpha(k)=αβ(k)Calculating to obtain the kth iteration weighting coefficient which is marked as alpha(k)(ii) a Using a formulaCalculating to obtain a scattering coefficient vector of the kth iteration, and recording asWhere α is the weighting factor initialized in step 7, β(k)For the noise power of the kth iteration, g is the observation vector matrix in step 5, Φ is the measurement matrix in step 6, Λ(k)For the diagonal matrix of the kth iteration in step 7, H is the sign of the conjugate transpose operation in definition 5, (-)-1To define the standard matrix inversion operator in 6.
Using a formulaCalculating to obtain the kth iterative noise power which is marked as beta(k). N is the number of voyages initialized in step 1, g is the observation vector matrix in step 5, phi is the measurement matrix in step 6,is the scattering coefficient vector of the kth iteration in step 9, | · | | calving2Is L in definition 32The norm solves the operator.
Step 11, judging whether the iteration termination condition is met, reconstructing height direction information to obtain the final three-dimensional imaging result if the iteration termination condition is metAnd k is less than or equal to IiterThen, the steps 8 to 11 are continuously executed.
If not satisfied withAnd k is less than or equal to IiterEither condition, the algorithm iteration terminates, then the outputThe obtained K iteration scattering coefficient of the SBRIM algorithmNamely the final three-dimensional imaging result of the multi-baseline chromatography SAR. Where ε is the reconstruction error threshold initialized in step 7, IiterFor the total number of iterations initialized in step 7,the vector of scattering coefficient of the kth iteration in step 9, | · | | computationally2Is L in definition 32The norm solves the operator. Through the steps, a multi-baseline tomography SAR three-dimensional imaging result based on the SBRIM algorithm is obtained.
The invention has the innovation points that a multi-baseline tomography SAR three-dimensional imaging method based on an SBRIM algorithm is provided, and aims at the problems of low resolution and fuzziness of the traditional three-dimensional imaging algorithm caused by insufficient number of navigated objects and nonuniform navigated objects in the tomography SAR three-dimensional imaging process.
Compared with the traditional sparse reconstruction algorithm, the method has the advantages that the advantages of three-dimensional imaging under sparse aerial distribution of the traditional algorithm can be kept, the number of algorithm parameters is reduced, the chromatographic resolution is improved, the three-dimensional image can be reconstructed under less observation data, the precision of signal sparse reconstruction is improved, and in addition, a more stable imaging effect can be obtained under the condition of low signal to noise ratio.
Drawings
FIG. 1 is a schematic block flow diagram of a method provided by the present invention;
fig. 2 shows a tomography SAR three-dimensional imaging simulation parameter of the method provided by the present invention.
Detailed Description
The invention mainly adopts a simulation experiment method for verification, and all steps and conclusions are verified to be correct on MATLAB R2017b software. The specific implementation steps are as follows:
Initializing multi-baseline tomosynthesis SAR system parameters includes: the number of voyages is recorded as N-21; vertical base line, denoted b⊥nWherein b is⊥1=2000m,b⊥n=(b⊥1-n 200+200) m, n 1, 2.., 21; parallel base lines, denoted b||nWherein b is||1=0m,b||n0m, n 1,2, 21; carrier frequency of radar emission signal fc10 GHz; the frequency modulation slope of the radar emission signal is fdr=2×1015Hz/s; the pulse repetition frequency of the radar system is PRF 1024; the bandwidth of the radar emission signal is marked as Br200 MHz; the propagation speed of electromagnetic waves in air is denoted by C3 × 108m/s; the fast time of the distance direction is marked as T, T is 1,2, the.. the T, T is 1024 and is the total number of the fast time of the distance direction, the slow time of the azimuth direction is marked as l, l is 1,2, the.. the K, K is 2048 and is the total number of the slow time of the azimuth direction; the parameters are all standard parameters of the SAR system and are determined in the design of a multi-baseline chromatography SAR observation scheme; according to the multi-baseline tomographic SAR imaging system scheme and the observation scheme, initialized imaging system parameters required by the SAR imaging method are known.
Step 2: observation scene target space parameter for initializing multi-baseline chromatography SAR
Initializing observation scene target space parameters of the array SAR comprises the following steps: taking a space rectangular coordinate system formed by a ground plane of a radar beam irradiation area and a unit vector vertical to the ground plane upwards as an observation scene target space omega of the array SAR; Ω is 101 × 101 × 101 pixels; uniformly dividing an observation scene target space omega into three-dimensional unit grids with equal size, called resolution units, and respectively recording the side lengths of the three-dimensional unit grids in the horizontal transverse direction, the horizontal longitudinal direction and the height direction as dx=1m,dy1m and dzThe unit grid number of the observation scene space in the horizontal transverse direction, the horizontal longitudinal direction and the height direction is M respectively as 1Mx=51,My51 and Mz512, the unit grid size is the traditional theoretical imaging resolution of the array SAR system; the horizontal transverse direction and the horizontal longitudinal direction form an array plane dimension imaging space, and the position of the mth element of the tth equidistant stereo unit grid on the array plane dimension imaging space is recorded asWherein m is 51 (m)y-1)+mxM is the total number of t-th equidistant stereo unit grid array to stereo unit grid of the array plane dimension imaging space, M is Mx×My=2601,mx=1,...,51,my=1,...,51,t=1,2,...,1024;
Recording the scattering coefficient of the mth element of the tth equidistant stereo unit grid in the target space of the observation scene as delta tm1,2,., 2601, t 1,2,.., 1024; using a formulaCalculating to obtain a scattering coefficient matrix, and recording the scattering coefficient matrix as delta, wherein the scattering coefficient matrix delta consists of 2601 rows and 1024 columns; according to the SAR imaging method processing scheme of the multi-baseline tomography SAR based on the SBRIM algorithm, the observation scene target space parameters required for initializing the multi-baseline tomography SAR are known.
Step 3, generating original echo data, and performing range-azimuth two-dimensional SAR imaging on each echo data acquired by navigation
The n-th navigated raw echo data of the multi-baseline SAR in the l-th azimuth slow time and the t-th distance fast time is marked as s (t, l, n), t is 1,2, 1, 1024, l is 1,2, 2048, n is 1,2, 21, wherein t is the distance fast time, l is the azimuth slow time, and n is each navigating sequence number; in multi-baseline tomography SAR real imaging, raw echo data s (t, l, n) is provided by a data receiver.
Distance-direction two-dimensional SAR imaging method for original echo data s (t, l, n) in definition 8 is adopted to carry out distance-direction two-dimensional SAR imagingSAR imaging to obtain image data of each voyaget 1,2, 1, 1024, l 1,2, 2048, n 1,2, 21, where t is the time instant of the fast direction, l is the time instant of the slow direction, and n is the respective flight sequence number.
Step 4, carrying out image registration on the obtained SAR imaging, and carrying out deskew processing to obtain an observation vector
And (3) registering the image sequences acquired by each navigation in the step (3) by using a traditional image registration method, so that the same distance-orientation unit corresponds to the same scattering point in the target scene, and obtaining a registered image sequence h (t, l, n), wherein t is 1,2,., 1024, l is 1,2,., 2048, and n is 1,2,., 21, t is a fast moment of the distance direction, l is a slow moment of the orientation direction, and n is a sequence number of each navigation.
Using a formulan 1,2, 21, calculating the slope distance R of each passing platform from the reference pointn(s) wherein the target position of the chromatographic orientation point is (r)0S) each passing radar platform is in the position of (b)||n,b⊥n). Using a formulan is 1,2, 21, and calculating a deskewed observation signal vector g (t, l, n), where h (t, l, n) is a registered image sequence, and R isn(0) Is a reference point (r)00) a reference slant distance to each passing radar platform, t 1,2,.., 1024, l 1,2,., 2048, n 1,2,. once, 21, where t is a fast time of distance, l is a slow time of azimuth, and n is each passing sequence number.
And 5: constructing an observation vector matrix
Using g ═ g1,g2,...,gN]TConstructing an observation vector matrix, wherein gnG (t, l, n), t 1,2,., 1024, l 1,2,., 2048, n 1,2,., 21, which is the signal after the deskew process in step 4, t is the fast time of the distance direction, l is the slow time of the directionAnd n is each navigation serial number.
Step 6, discretizing a scene target and constructing a measurement matrix
According to the formulaCalculating to obtain the spatial frequency of the nth orbital tomography direction, and recording as xi n1,2, ·, 21; and then discretizing the position of the scene target in the tomography direction by D-101 uniform points sd1,2, 101, using the formulaCalculating to obtain a measurement matrix, and recording as phi; wherein the target position of the chromatographic directional point is (r)0,s),b⊥n=(b⊥1N 200+200) m, n 1,2, 21, the vertical baseline of the nth track sub-image with respect to the main image initialized in step 1, b||n0m, n 1,2, 21, which is the parallel baseline of the nth track sub-image initialized in step 1 with respect to the main image, fcThe carrier frequency of the radar transmission signal initialized in step 1 is 10GHz, and C is 3 × 108And m/s is the propagation speed of the electromagnetic wave initialized in the step 1 in the air.
Step 7, initializing SBRIM algorithm parameters
The initialization parameters of the SBRIM algorithm comprise: the weighting coefficient is recorded as alpha being 1; the reconstruction error threshold is marked as epsilon 10-5(ii) a Noise power, noted as β ═ 1; total number of iterations, denoted Iiter100; the iteration times are recorded as k being 0; smoothing factor, noted as η 10-6(ii) a The diagonal matrix control parameter is recorded as p 1; according to the formulaCalculating to obtain an initialized signal estimation valueWherein g is the observation vector matrix in step 5, Φ is the measurement matrix in step 6, and H is the conjugate transpose operator in definition 5.
Updating iteration times, calculating to obtain updated iteration times according to a formula k which is k +1, and recording as k; according to the formulaCalculating to obtain a diagonal matrix of the kth iteration, and recording the diagonal matrix as Lambda(k). Where N ═ 21 is the number of flights initialized in step 1, p ═ 1 is the diagonal matrix control parameter initialized in step 7, and η ═ 10-6For the smoothing factor initialized in step 7,for the scattering coefficient estimate for the ith satellite orbit data in the k-1 iteration cycle, diag {. cndot } is the sign of the diagonal matrix operation in definition 4.
Step 9, estimating scattering coefficient vector
According to the formula alpha(k)=αβ(k)Calculating to obtain the kth iteration weighting coefficient which is marked as alpha(k)(ii) a According to the formulaCalculating to obtain a scattering coefficient vector of the kth iteration, and recording asWhere α ═ 1 is the weighting coefficient initialized in step 7, β(k)For the noise power of the kth iteration, g is the observation vector matrix in step 5, Φ is the measurement matrix in step 6, Λ(k)For the diagonal matrix of the kth iteration in step 7, H is the sign of the conjugate transpose operation in definition 5, (-)-1To define the standard matrix inversion operator in 6.
Using a formulaCalculating to obtain the kth iterative noise power which is marked as beta(k). Wherein N-21 is in step 1Initializing the obtained navigation times, g is an observation vector matrix in the step 5, phi is a measurement matrix in the step 4,the vector of scattering coefficient of the kth iteration in step 9, | · | | computationally2Is L in definition 32The norm solves the operator.
Step 11, judging whether the iteration termination condition is met, reconstructing height direction information to obtain the final three-dimensional imaging result if the iteration termination condition is metAnd k is less than or equal to IiterThen, the steps 8 to 11 are continuously executed.
If not satisfied withAnd k is less than or equal to IiterEither condition, the algorithm iteration terminates, then the outputThe obtained K iteration scattering coefficient of the SBRIM algorithmNamely the final three-dimensional imaging result of the multi-baseline chromatography SAR. Wherein ε is 10-5For the reconstruction error threshold initialized in step 7, Iiter100 is the total number of iterations initialized in step 7,the vector of scattering coefficient of the kth iteration in step 9, | · | | computationally2Is L in definition 32The norm solves the operator. Through the steps, a multi-baseline tomography SAR three-dimensional imaging result based on the SBRIM algorithm can be obtained.
The invention introduces the SBRIM algorithm into the tomography SAR imaging by using a small amount of navigation data and conducts sparse reconstruction in the tomography direction to obtain the three-dimensional imaging result of a target scene, compared with the traditional sparse reconstruction method which constructs a measurement matrix by using all echo data, the invention reduces the algorithm operation amount, improves the tomography direction resolution and the signal sparse reconstruction precision, and can obtain more stable imaging effect under the condition of low signal to noise ratio.
Claims (1)
1. A multi-baseline chromatography SAR three-dimensional imaging method based on an SBRIM algorithm is characterized by comprising the following steps:
step 1, initializing parameters of a multi-baseline chromatography SAR system
Initializing multi-baseline tomosynthesis SAR system parameters includes: the number of voyage times is marked as N; vertical base line, denoted b⊥nParallel base line, denoted b||nN is 1,2, …, N, where N is the number of flights; carrier frequency of radar emission signal fc(ii) a The frequency modulation slope of the radar emission signal is fdr(ii) a The pulse repetition frequency of the radar system is PRF; the bandwidth of the radar emission signal is marked as Br(ii) a The propagation speed of the electromagnetic waves in the air is marked as C; distance fast time is marked as T, T is 1,2, …, T, T is the total distance fast time, azimuth slow time is marked as l, l is 1,2, …, K, K is the total azimuth slow time; the parameters are all standard parameters of the SAR system and are determined in the design of a multi-baseline chromatography SAR observation scheme; according to the multi-baseline tomography SAR imaging system scheme and the observation scheme, the parameters of an initialized imaging system required by the SAR imaging method are known;
step 2: observation scene target space parameter for initializing multi-baseline chromatography SAR
Initializing observation scene target space parameters of the multi-baseline tomography SAR comprises the following steps: a spatial rectangular coordinate system formed by a ground plane of a radar beam irradiation area and a unit vector vertical to the ground plane upwards is used as an observation scene target space omega of the multi-baseline tomography SAR, wherein omega is Mx×My×MzA pixel; uniformly dividing an observation scene target space omega into three-dimensional unit grids with equal size, called resolution units, and respectively recording the side lengths of the three-dimensional unit grids in the horizontal transverse direction, the horizontal longitudinal direction and the height direction as dx,dyAnd dzObserving the horizontal and horizontal direction of the target space of the sceneThe number of the horizontal and vertical unit grids is Mx,MyAnd MzThe unit grid size is the traditional theoretical imaging resolution of the multi-baseline chromatography SAR system; a two-dimensional plane imaging space is formed by the horizontal transverse direction and the horizontal longitudinal direction, and the position of the mth element of the tth equidistant stereo unit grid on the two-dimensional plane imaging space is recorded asWherein m is (m)y-1)Mx+mxM is the t-th equidistant solid cell grid height to the total solid cell grid number of the two-dimensional planar imaging space, M is 1, …, Mx·My,mx=1,…,Mx,my=1,…,MyT is 1, …, and T is the total number of the distance fast time obtained by initialization in step 1;
recording the scattering coefficient of the mth element of the tth equidistant stereo unit grid in the target space of the observation scene as Using a formulaCalculating to obtain a scattering coefficient matrix, and recording the scattering coefficient matrix as delta, wherein the scattering coefficient matrix delta is composed of M rows and T columns, T is the total number of the distance fast-forward moments obtained by initialization in the step 1, M is the total number of the T-th equidistant stereo unit grid array of the two-dimensional planar imaging space to the stereo unit grid, and M is equal to Mx·My(ii) a According to the SAR imaging method processing scheme of the multi-baseline tomography SAR based on the SBRIM algorithm, target space parameters of an observation scene for initializing the multi-baseline tomography SAR are known;
step 3, generating original echo data, and performing range-azimuth two-dimensional SAR imaging on each echo data acquired by navigation
The nth navigated raw echo data of the multi-baseline SAR at the l-th azimuth slow time and the T-th range fast time is denoted as s (T, l, N), T is 1,2, …, T, l is 1,2, …, K, N is 1,2, …, N; in the multi-baseline chromatography SAR actual imaging, original echo data s (t, l, n) is provided by a data receiver;
performing distance-direction two-dimensional SAR imaging on the original echo data s (t, l, n) by adopting a two-dimensional SAR imaging method to obtain image data of each voyageWherein T is the total number of the distance fast moments initialized in the step 1, T is the distance fast moments, K is the total number of the azimuth slow moments initialized in the step 1, l is the azimuth slow moment, N is the number of voyage times initialized in the step 1, and N is each voyage serial number;
step 4, carrying out image registration on the obtained SAR imaging, and carrying out deskew processing to obtain an observation vector
Registering the image sequences acquired in each voyage in step 3 by using a conventional image registration method, so that the same distance-orientation unit corresponds to the same scattering point in the target scene, and obtaining a registered image sequence h (T, l, N), where T is 1,2, …, T, l is 1,2, …, K, N is 1,2, …, N;
using a formulaCalculating the slope distance R between each navigation platform and the reference pointn(s) wherein the target position of the chromatographic orientation point is (r)0S) each passing radar platform is in the position of (b)||n,b⊥n) (ii) a Using a formulaCalculating to obtain a de-skewed observation signal vector g (t, l, n), wherein h (t, l, n) is a registered image sequence, and Rn(0) Is a reference point (r)00) reference slope to each of the airborne radar platforms, T1, 2, …, T, l 1,2, …, K, N1, 2, …, N, where T is the total number of fast-forward moments initialized in step 1, and T is the total number of fast-forward momentsAt a fast moment, K is the total number of azimuth slow moments obtained by initialization in the step 1, l is the azimuth slow moment, N is the total number of voyages obtained by initialization in the step 1, and N is a voyage serial number;
and 5: constructing an observation vector matrix
Using g ═ g1,g2,...,gN]TConstructing an observation vector matrix, wherein gnG (T, l, N), T1, 2, …, T, l 1,2, …, K, N1, 2, …, N, and N, where T is the total number of fast-direction moments initialized in step 1, K is the total number of slow-direction moments initialized in step 1, l is the slow-direction moment, N is the number of voyages initialized in step 1, and N is the number of voyages;
step 6, discretizing a scene target and constructing a measurement matrix
Using a formulaCalculating to obtain the spatial frequency of the nth orbital tomography direction, and recording as xinN is 1,2, …, N; discretizing the position of the scene target in a chromatography position by D uniform points sdD is 1,2, …, D, using the formulaCalculating to obtain a measurement matrix, and recording as phi; wherein the target position of the chromatographic directional point is (r)0,s),b⊥nFor the vertical baseline of the nth track auxiliary image initialized in step 1 with respect to the main image, b||nFor the parallel baseline of the nth track side image initialized in step 1 with respect to the main image, fcC is the transmission speed of the electromagnetic wave initialized in the step 1 in the air;
step 7, initializing SBRIM algorithm parameters
The initialization parameters of the SBRIM algorithm comprise: a weighting coefficient, noted as α; reconstructing an error threshold, and recording as epsilon; noise power, denoted as β; total number of iterations denoted Iiter(ii) a The iteration times are marked as k; flat plateSlip factor, denoted as η; the diagonal matrix control parameter is marked as p; using a formulaCalculating to obtain an initialized signal estimation valueWherein g is an observation vector matrix in the step 5, phi is a measurement matrix in the step 6, and H is a conjugate transpose operation symbol;
step 8, calculating a diagonal matrix
Updating iteration times, calculating to obtain updated iteration times by adopting a formula k which is k +1, and marking as k; using a formulaCalculating to obtain a diagonal matrix of the kth iteration, and recording the diagonal matrix as Lambda(k)(ii) a Wherein
N is the number of voyages initialized in the step 1, p is the diagonal matrix control parameter initialized in the step 7, eta is the smoothing factor initialized in the step 7,the scattering coefficient estimation value of the ith satellite orbit data in the (k-1) th iteration cycle is shown, and diag {. cndot } is a diagonal matrix operation symbol;
step 9, estimating scattering coefficient vector
Using the formula alpha(k)=αβ(k)Calculating to obtain the kth iteration weighting coefficient which is marked as alpha(k)(ii) a Using a formulaCalculating to obtain a scattering coefficient vector of the kth iteration, and recording asWhere α is the weighting factor initialized in step 7, β(k)Noise work for the kth iterationThe ratio g is the observation vector matrix in step 5, phi is the measurement matrix in step 6, lambda(k)For the diagonal matrix of the kth iteration in step 7, H is the conjugate transpose symbol, (. cndot.)-1Matrix inversion operators;
step 10, estimating noise power
Using a formulaCalculating to obtain the kth iterative noise power which is marked as beta(k)(ii) a Wherein N is the navigation times initialized in the step 1, g is the observation vector matrix in the step 5, phi is the measurement matrix in the step 6,the vector of scattering coefficient of the kth iteration in step 9, | · | | computationally2Is L2The norm solves the operator;
step 11, judging whether the iteration termination condition is met, reconstructing height direction information to obtain a final three-dimensional imaging result
if not satisfied withAnd k is less than or equal to IiterEither condition, the algorithm iteration terminates, then the outputThe obtained K iteration scattering coefficient of the SBRIM algorithmThe three-dimensional imaging result is the final three-dimensional imaging result of the multi-baseline chromatography SAR; where ε is the reconstruction error threshold initialized in step 7, IiterFor the iteration initialized in step 7The total number of the first and second batteries,the vector of scattering coefficient of the kth iteration in step 9, | · | | computationally2Is L2The norm solves the operator; through the steps, a multi-baseline tomography SAR three-dimensional imaging result based on the SBRIM algorithm is obtained.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202010467200.3A CN111679277B (en) | 2020-05-28 | 2020-05-28 | Multi-baseline chromatography SAR three-dimensional imaging method based on SBRIM algorithm |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202010467200.3A CN111679277B (en) | 2020-05-28 | 2020-05-28 | Multi-baseline chromatography SAR three-dimensional imaging method based on SBRIM algorithm |
Publications (2)
Publication Number | Publication Date |
---|---|
CN111679277A CN111679277A (en) | 2020-09-18 |
CN111679277B true CN111679277B (en) | 2022-05-03 |
Family
ID=72453586
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202010467200.3A Active CN111679277B (en) | 2020-05-28 | 2020-05-28 | Multi-baseline chromatography SAR three-dimensional imaging method based on SBRIM algorithm |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN111679277B (en) |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112948606B (en) * | 2020-12-14 | 2022-10-21 | 西南交通大学 | Signal estimation method and device based on self-adaptive grid |
CN112734812B (en) * | 2020-12-24 | 2023-07-11 | 北京建筑大学 | Method, device, electronic equipment and storage medium for determining number of scatterers |
CN112986992A (en) * | 2021-02-06 | 2021-06-18 | 中国人民解放军国防科技大学 | SAR (synthetic Aperture Radar) tomography rapid imaging method based on compressed sensing |
CN113189588B (en) * | 2021-04-30 | 2022-05-03 | 电子科技大学 | High frame rate imaging method for cluster unmanned aerial vehicle synthetic aperture radar |
CN113514828B (en) * | 2021-06-29 | 2024-04-26 | 广东万育产业发展咨询有限公司 | Ship image dataset application method and system based on Beidou satellite system |
CN113835090B (en) * | 2021-08-31 | 2024-04-12 | 电子科技大学 | High-precision interference phase acquisition method based on multichannel SAR system |
CN114002674A (en) * | 2021-10-08 | 2022-02-01 | 电子科技大学 | Multiple-overlapping-movement target position and speed estimation method based on SBRIM |
CN114879188A (en) * | 2022-04-20 | 2022-08-09 | 北京理工大学 | Model self-adaptive deep learning SAR three-dimensional imaging method |
CN117289277B (en) * | 2023-11-27 | 2024-01-30 | 中山大学 | Multi-frequency radar three-dimensional imaging method and system based on subband segmentation synthesis |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7170440B1 (en) * | 2005-12-10 | 2007-01-30 | Landray Technology, Inc. | Linear FM radar |
CN102662171A (en) * | 2012-04-23 | 2012-09-12 | 电子科技大学 | Synthetic aperture radar (SAR) tomography three-dimensional imaging method |
CN103713288A (en) * | 2013-12-31 | 2014-04-09 | 电子科技大学 | Linear array SAR imaging method based on iterative minimization sparse Bayesian reconstitution |
CN104833973A (en) * | 2015-05-08 | 2015-08-12 | 电子科技大学 | Linear array SAR backward projection self-focusing imaging method based on positive semi-definite programming |
CN106872977A (en) * | 2016-12-28 | 2017-06-20 | 北京建筑大学 | A kind of chromatography SAR three-D imaging methods based on the weak orthogonal matching pursuit of segmentation |
CN108226927A (en) * | 2017-12-14 | 2018-06-29 | 电子科技大学 | SAR imaging methods based on weighted iteration minimum sparse Bayesian restructing algorithm |
CN110082764A (en) * | 2019-04-26 | 2019-08-02 | 西安电子科技大学 | SAR image imaging method based on steady regularization chromatography method |
CN110109101A (en) * | 2019-04-04 | 2019-08-09 | 电子科技大学 | A kind of compressed sensing three-dimensional S AR imaging method based on adaptive threshold |
CN110133656A (en) * | 2019-06-06 | 2019-08-16 | 电子科技大学 | A kind of sparse imaging method of three-dimensional S AR for decomposing with merging based on relatively prime array |
CN111145337A (en) * | 2019-12-13 | 2020-05-12 | 电子科技大学 | Linear array SAR three-dimensional imaging method based on resolution approximation and rapid sparse reconstruction |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10160399B4 (en) * | 2001-12-10 | 2004-05-27 | Deutsches Zentrum für Luft- und Raumfahrt e.V. | Airplane or satellite-based tomographic radar process with synthetic aperture |
-
2020
- 2020-05-28 CN CN202010467200.3A patent/CN111679277B/en active Active
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7170440B1 (en) * | 2005-12-10 | 2007-01-30 | Landray Technology, Inc. | Linear FM radar |
CN102662171A (en) * | 2012-04-23 | 2012-09-12 | 电子科技大学 | Synthetic aperture radar (SAR) tomography three-dimensional imaging method |
CN103713288A (en) * | 2013-12-31 | 2014-04-09 | 电子科技大学 | Linear array SAR imaging method based on iterative minimization sparse Bayesian reconstitution |
CN104833973A (en) * | 2015-05-08 | 2015-08-12 | 电子科技大学 | Linear array SAR backward projection self-focusing imaging method based on positive semi-definite programming |
CN106872977A (en) * | 2016-12-28 | 2017-06-20 | 北京建筑大学 | A kind of chromatography SAR three-D imaging methods based on the weak orthogonal matching pursuit of segmentation |
CN108226927A (en) * | 2017-12-14 | 2018-06-29 | 电子科技大学 | SAR imaging methods based on weighted iteration minimum sparse Bayesian restructing algorithm |
CN110109101A (en) * | 2019-04-04 | 2019-08-09 | 电子科技大学 | A kind of compressed sensing three-dimensional S AR imaging method based on adaptive threshold |
CN110082764A (en) * | 2019-04-26 | 2019-08-02 | 西安电子科技大学 | SAR image imaging method based on steady regularization chromatography method |
CN110133656A (en) * | 2019-06-06 | 2019-08-16 | 电子科技大学 | A kind of sparse imaging method of three-dimensional S AR for decomposing with merging based on relatively prime array |
CN111145337A (en) * | 2019-12-13 | 2020-05-12 | 电子科技大学 | Linear array SAR three-dimensional imaging method based on resolution approximation and rapid sparse reconstruction |
Non-Patent Citations (9)
Title |
---|
A Fast Sparse Recovery Algorithm via Resolution Approximation for LASAR 3D Imaging;Tian, BK等;《IEEE ACCESS》;20190130;全文 * |
First demonstration of airborne SAR tomography using multibaseline L-band data;Reigber, A.Moreira等;《IEEE 1999 International Geoscience and Remote Sensing Symposium. IGARSS》;19901001;全文 * |
SAR层析三维成像技术研究;王金峰;《万方数据库》;20101222;全文 * |
Yue Wu ; 等.Multi-Baseline Synthetic Aperture Radar 3-D Imaging via the Same Spatial Surface Projection.《2019 6th Asia-Pacific Conference on Synthetic Aperture Radar (APSAR)》.2020, * |
基于互质阵列的线阵SAR三维联合稀疏成像;张星月;《第六届高分辨率对地观测学术年会论文集(上)》;20190920;全文 * |
基于压缩感知的多基线星载SAR图像仿真及三维成像;高君路;《万方数据库》;20140331;全文 * |
基于稀疏贝叶斯正则化的阵列SAR高分辨三维成像算法;闫敏;《雷达学报》;20181208;全文 * |
线阵三维SAR稀疏成像方法研究;左林电;《万方数据库》;20180208;全文 * |
线阵三维合成孔径雷达稀疏成像技术研究;韦顺军;《中国博士学位论文全文数据库 信息科技辑》;20130915;全文 * |
Also Published As
Publication number | Publication date |
---|---|
CN111679277A (en) | 2020-09-18 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN111679277B (en) | Multi-baseline chromatography SAR three-dimensional imaging method based on SBRIM algorithm | |
CN107037429B (en) | Linear array SAR three-dimensional imaging method based on threshold gradient tracking algorithm | |
CN109061642B (en) | Bayes iteration reweighing sparse self-focusing array SAR imaging method | |
CN107193003B (en) | Sparse singular value decomposition scanning radar foresight imaging method | |
CN108226927B (en) | SAR imaging method based on weighted iteration minimum sparse Bayesian reconstruction algorithm | |
Yang et al. | Segmented reconstruction for compressed sensing SAR imaging | |
Zhang et al. | Superresolution downward-looking linear array three-dimensional SAR imaging based on two-dimensional compressive sensing | |
CN110244303B (en) | SBL-ADMM-based sparse aperture ISAR imaging method | |
Sun et al. | Multichannel full-aperture azimuth processing for beam steering SAR | |
Andersson et al. | Fast Fourier methods for synthetic aperture radar imaging | |
CN111145337B (en) | Linear array SAR three-dimensional imaging method based on resolution approximation and rapid sparse reconstruction | |
CN104950306A (en) | Method for realizing angular super-resolution imaging of forward-looking sea surface targets in sea clutter background | |
CN105699969A (en) | A maximum posterior estimated angle super-resolution imaging method based on generalized Gaussian constraints | |
CN109597075B (en) | Imaging method and imaging device based on sparse array | |
CN110109101A (en) | A kind of compressed sensing three-dimensional S AR imaging method based on adaptive threshold | |
Quan et al. | Microwave correlation forward-looking super-resolution imaging based on compressed sensing | |
Wu et al. | Fast 3-D imaging algorithm based on unitary transformation and real-valued sparse representation for MIMO array SAR | |
CN112147608A (en) | Rapid Gaussian gridding non-uniform FFT through-wall imaging radar BP method | |
CN113608218B (en) | Frequency domain interference phase sparse reconstruction method based on back projection principle | |
CN105891827A (en) | Machine-mounted MIMO-SAR downward-looking three dimensional sparse imaging method | |
CN109143236B (en) | Bistatic bunching SAR large-scene imaging method suitable for complex flight trajectory | |
CN113064165B (en) | Scanning radar pitch-azimuth two-dimensional super-resolution method | |
Bouzerdoum et al. | A low-rank and jointly-sparse approach for multipolarization through-wall radar imaging | |
CN110133656B (en) | Three-dimensional SAR sparse imaging method based on decomposition and fusion of co-prime array | |
Kang et al. | Downward-looking linear array three-dimensional SAR imaging based on the two-dimensional mismatch compensation |
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 | ||
GR01 | Patent grant | ||
GR01 | Patent grant |