CN103630907A - Interpolation-free reconstruction method for near-distance active millimeter-wave cylindrical scanning imaging system - Google Patents

Interpolation-free reconstruction method for near-distance active millimeter-wave cylindrical scanning imaging system Download PDF

Info

Publication number
CN103630907A
CN103630907A CN201310716710.XA CN201310716710A CN103630907A CN 103630907 A CN103630907 A CN 103630907A CN 201310716710 A CN201310716710 A CN 201310716710A CN 103630907 A CN103630907 A CN 103630907A
Authority
CN
China
Prior art keywords
imaging system
interpolation
dimensional
fourier transform
scanning imaging
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.)
Granted
Application number
CN201310716710.XA
Other languages
Chinese (zh)
Other versions
CN103630907B (en
Inventor
温鑫
方维海
费鹏
年丰
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.)
Beijing Institute of Radio Metrology and Measurement
Original Assignee
Beijing Institute of Radio Metrology and Measurement
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 Beijing Institute of Radio Metrology and Measurement filed Critical Beijing Institute of Radio Metrology and Measurement
Priority to CN201310716710.XA priority Critical patent/CN103630907B/en
Publication of CN103630907A publication Critical patent/CN103630907A/en
Application granted granted Critical
Publication of CN103630907B publication Critical patent/CN103630907B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • 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
    • G01S7/28—Details of pulse systems

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 provides an interpolation-free reconstruction method for a near-distance active millimeter-wave cylindrical scanning imaging system. In the method, a three-dimensional NUFFT (Non-uniform Fast Fourier Transform) matrix is established and is applied to a digital reconstruction algorithm which uses spatial frequency interpolation for the near-distance active millimeter-wave cylindrical scanning imaging system, so that reduction of computation errors and shortening of computation time in a reconstruction process are realized. According to the interpolation-free reconstruction method, the imaging quality of the imaging system can be enhanced effectively, and the computation time of the system is shortened.

Description

Closely active millimeter wave cylinder scanning imaging system exempts from interpolation reconstruction method
Technical field
The present invention relates to a kind of interpolation reconstruction method of exempting from of closely active millimeter wave cylinder scanning imaging system.
Background technology
Interpolation arithmetic is closely to introduce the longest step of error of calculation maximum, computing time in active millimeter wave cylinder scanning imaging system image reconstruction procedure, how effectively to reduce the error of introducing in interpolation process and the computing time that reduces system becomes the closely gordian technique of active millimeter wave cylinder scanning imagery.
At present, applied for and relevant scientific paper in the algorithm of the three-dimensional image reconstruct that adopts have restructing algorithm, wavefront reconstruction algorithm and the restructing algorithm based on compressed sensing based on approximation method.Restructing algorithm based on approximation method comprises polar format to be processed, RANGE-DOPPLER IMAGING, and the approximate value of institute's foundation has limited the size of target area, radar frequency or synthetic aperture scope.The restriction of restructing algorithm based on approximation method to application conditions, makes being of limited application of it, and is not suitable for the occasion that imaging precision is had relatively high expectations.At present, main wavefront reconstruction method has: by the digital reconstruction of spatial frequency interpolation, piled up and realized digital reconstruction and by the digital reconstruction that time domain is correlated with and rear orientation projection realizes by distance.Digital reconstruction by spatial frequency interpolation is to complete being uniformly distributed of sample point by spatial frequency domain interpolation, and the interpolation in spatial frequency domain is degenerated the edge that causes spatial domain to rebuild image.Because the operand of the digital reconstruction by spatial frequency interpolation is little, be applicable to the condition of real-time operation, so this imaging algorithm is by a large amount of uses.Distance is piled up and to be realized digital reconstruction algorithm and the Fourier transform of the reference signal in measuring-signal Fourier transform and respective distances is carried out to the repetitive operations such as matched filtering and cover whole target area.Distance heap integration method does not need interpolation, therefore be not subject to the impact of truncation error, and, also do not comprise the crossover error of discrete Fourier transform (DFT), yet, the realization that distance is piled up is more consuming time than the digital reconstruction method by spatial frequency interpolation, and this has limited the application of this algorithm in actual imaging system.Time domain digital reconstruction algorithm relevant and that rear orientation projection realizes utilizes variable filter to carry out convolution algorithm to sampled signal and realizes reconstruct.The ultimate principle of relevant (TDC) formation method of time domain is the related realization of matched filtering only, make to shut away mutually to data measured in the sampled signal feature on fixed grid point and fast time domain and slow time domain, result is exactly the measurement of this grid point reflectivity.The major defect of TDC method is the height that assesses the cost, this is owing to being the relevant discrete summation of carrying out, and over-sampling causes.Back-projection algorithm is in order to form in spatial domain the objective function to fixed grid point, and for all synthetic aperture position, we can be added the data coherency on the fast time domain unit corresponding with this position.In implementation procedure, must fast time domain sampling carry out interpolation to the signal discrete after fast time domain matched filtering, if do not adopt enough accurate interpolation, will cause the loss of high resolution information.The restructing algorithm of compressed sensing is a kind of sparse property of signal or compressible signal acquisition and reconstruct theory of making full use of, and three key points that compressed sensing is applied to imaging are Analysis of Radar echo datas, set up the sparse model of signal; Construct incoherent measurement matrix, determine rational observation model; Utilize compression sampling result, design is sane restructing algorithm effectively.Because Radar Target Scatter body is the set of the combinations such as shock pulse, step function, doublets, limited the sparse hypothesis of signal, and in the face of the changeable target of actual complex, whether this restructing algorithm is applicable to the closely still further research of needs of active millimeter wave three-dimensional imaging occasion.
Summary of the invention
For above the deficiencies in the prior art, the invention provides a kind of interpolation reconstruction method of exempting from of closely active millimeter wave cylinder scanning imaging system, to improve the computing time of image quality and the minimizing system of imaging system.
Object of the present invention is achieved through the following technical solutions:
Closely the interpolation reconstruction method of exempting from of active millimeter wave cylinder scanning imaging system comprises the steps:
S1. the sampled data of imaging system is carried out to two-dimension fourier transform along θ and z direction;
S2. the result of step 1 is carried out to phase compensation;
S3. the result of step 2 is carried out to inverse Fourier transform along θ direction;
S4. along 2k rcos θ, 2k rsin θ and k zsampling location, set up NUFFT three-dimensional matrice;
S5. the NUFFT three-dimensional matrice of setting up according to step 4, carries out three-dimensional inverse Fourier transform to the result of step 3.
Described step 1 is carried out Fourier transform, obtains data S (ω, ξ, k z).
During described step 2 phase compensation, by S (ω, ξ, k z) be multiplied by phase compensating factor
Figure BDA0000444011240000031
the sweep radius that wherein R is imaging system, k ω=ω c is defined as wave number,
Figure BDA0000444011240000032
The three-dimensional inverse Fourier transform of described step 4 comprises:
1) utilize the result of the 4th step to calculate fourier coefficient Y n * N * N=∑ Χ n * N * N* F σ(2k rcos θ, 2k rsin θ, k z);
2) utilize three-dimensional Fourier transfer pair Y n * N * Ncarry out computing and obtain σ ' (x, y, z);
3) σ ' (x, y, z) is become to mark and process σ (x, y, z)=σ ' (x, y, z) s -1obtain target three dimensions scatter intensity distribution σ (x, y, z), completed the three-dimensional reconstruction of target.
The invention has the advantages that:
Can effectively improve the image quality of imaging system and the computing time that reduces system.
Accompanying drawing explanation
Fig. 1 is active millimeter wave cylinder scanning imaging system schematic diagram closely.
Fig. 2 be a kind of closely active millimeter wave cylinder scanning imaging system exempt from interpolation reconstruction algorithm flow chart.
Embodiment
Below in conjunction with accompanying drawing, the present invention will be described in detail.The present invention is achieved by the following technical solutions: build three-dimensional NUFFT matrix, apply it in the digital reconstruction algorithm by spatial frequency interpolation of active millimeter wave cylinder scanning imaging system closely, thereby realize reducing and the minimizing of computing time of the error of calculation in restructuring procedure.
As shown in Figure 2, a kind of closely active millimeter wave cylinder scanning imaging system to exempt from interpolation reconstruction algorithm concrete steps as follows:
The first step: the sampled data of imaging system is carried out to two-dimension fourier transform along θ and z direction.
Active millimeter wave cylinder scanning imaging system schematic diagram closely as shown in Figure 1, closely the sampled data of active millimeter wave cylinder scanning imaging system 1 is S (ω, θ, z), wherein, ω represents the frequency that imaging system transmits, and θ represents to sample under aerial array 2 fixed angle at this moment, and z represents that the Antenna aperture of each transceiver channel is along the position of Z-direction.By carrying out two-dimension fourier transform along θ and z direction, become S (ω, ξ, k z).
Second step: the result of the first step is carried out to phase compensation
By S (ω, ξ, k z) be multiplied by phase compensating factor
Figure BDA0000444011240000041
the sweep radius that wherein R is imaging system, k ω=ω c is defined as wave number,
Figure BDA0000444011240000042
The 3rd step: the result of second step is carried out to inverse Fourier transform along θ direction.
Along θ direction, carrying out inverse Fourier transform obtains
F σ ( 2 k r cos θ , 2 k r sin θ , k z ) = F ( ξ ) - 1 [ S ( ω , ξ , k z ) e - j 4 k r 2 R 2 - ξ 2 ] .
The 4th step: along 2k rcos θ, 2k rsin θ and k zsampling location, set up NUFFT three-dimensional matrice.
Along 2k rcos θ, 2k rsin θ and k zeach direction in three directions utilizes cosine to become the mark factor
Figure BDA0000444011240000044
j=-N2 ..., N2 calculates the fourier coefficient of three directions wherein,
Figure BDA0000444011240000046
to integer m>=2, regulation ω=e i2 π mN, q is arbitrary integer, for each k=-q2 ..., q2's
Figure BDA0000444011240000047
be defined as follows:
A ‾ T A = N ω - N 2 - ω N 2 1 - ω · · · ω - N 2 q - ω N 2 q 1 - ω q ω N 2 - ω - N 2 1 - ω - 1 N · · · ω - ( q - 1 ) N 2 - ω ( q - 1 ) N 2 q 1 - ω q - 1 · · · ω N 2 q - ω - N 2 q 1 - ω q ω ( q - 1 ) N 2 - ω - ( q - 1 ) N 2 q 1 - ω q - 1 · · · N
Pass through 2k rcos θ, 2k rsin θ and k zthe fourier coefficient matrix multiple of three directions obtains the three-dimensional NUFFT three-dimensional matrice Χ of N * N * N n * N * N.Above calculating can be carried out being reconstructed between algorithm, can effectively reduce the operation time of system and the precision that improves reconstruction algorithm computes process.
The 5th step: utilize the NUFFT three-dimensional matrice of setting up in the 4th step, the result of the 3rd step is carried out to three-dimensional inverse Fourier transform.First, utilize the result of the 4th step to calculate fourier coefficient Y n * N * N=∑ Χ n * N * N* F σ(2k rcos θ, 2k rsin θ, k z); Then, utilize three-dimensional Fourier transfer pair Y n * N * Ncarry out computing and obtain σ ' (x, y, z); Finally, σ ' (x, y, z) is become to mark and process σ (x, y, z)=σ ' (x, y, z) s -1obtain target three dimensions scatter intensity distribution σ (x, y, z), completed the three-dimensional reconstruction of target.
Should be appreciated that the above detailed description of technical scheme of the present invention being carried out by preferred embodiment is illustrative and not restrictive.Those of ordinary skill in the art modifies reading the technical scheme that can record each embodiment on the basis of instructions of the present invention, or part technical characterictic is wherein equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution depart from the spirit and scope of various embodiments of the present invention technical scheme.

Claims (4)

  1. Closely active millimeter wave cylinder scanning imaging system exempt from interpolation reconstruction method, it is characterized in that, this reconstructing method comprises the steps:
    S1. the sampled data of imaging system is carried out to two-dimension fourier transform along θ and z direction;
    S2. the result of step 1 is carried out to phase compensation;
    S3. the result of step 2 is carried out to inverse Fourier transform along θ direction;
    S4. along 2k rcos θ, 2k rsin θ and k zsampling location, set up NUFFT three-dimensional matrice;
    S5. the NUFFT three-dimensional matrice of setting up according to step 4, carries out three-dimensional inverse Fourier transform to the result of step 3.
  2. Closely active millimeter wave cylinder scanning imaging system according to claim 1 exempt from interpolation reconstruction method, it is characterized in that, described step 1 is carried out Fourier transform, obtains data S (ω, ξ, k z).
  3. Closely active millimeter wave cylinder scanning imaging system according to claim 1 exempt from interpolation reconstruction method, it is characterized in that, during described step 2 phase compensation, by S (ω, ξ, k z) be multiplied by phase compensating factor the sweep radius that wherein R is imaging system, k ω=ω c is defined as wave number,
    k r = k ω 2 - k z 2 .
  4. Closely active millimeter wave cylinder scanning imaging system according to claim 1 exempt from interpolation reconstruction method, it is characterized in that, the three-dimensional inverse Fourier transform of described step 4 comprises:
    1) utilize the result of the 4th step to calculate fourier coefficient Y n * N * N=∑ Χ n * N * N* F σ(2k rcos θ, 2k rsin θ, k z);
    2) utilize three-dimensional Fourier transfer pair Y n * N * Ncarry out computing and obtain σ ' (x, y, z);
    3) σ ' (x, y, z) is become to mark and process σ (x, y, z)=σ ' (x, y, z) s -1obtain target three dimensions scatter intensity distribution σ (x, y, z), completed the three-dimensional reconstruction of target.
CN201310716710.XA 2013-12-23 2013-12-23 Closely active millimeter wave cylinder scanning imaging system exempt from interpolation reconstruction method Active CN103630907B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201310716710.XA CN103630907B (en) 2013-12-23 2013-12-23 Closely active millimeter wave cylinder scanning imaging system exempt from interpolation reconstruction method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201310716710.XA CN103630907B (en) 2013-12-23 2013-12-23 Closely active millimeter wave cylinder scanning imaging system exempt from interpolation reconstruction method

Publications (2)

Publication Number Publication Date
CN103630907A true CN103630907A (en) 2014-03-12
CN103630907B CN103630907B (en) 2016-09-14

Family

ID=50212157

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201310716710.XA Active CN103630907B (en) 2013-12-23 2013-12-23 Closely active millimeter wave cylinder scanning imaging system exempt from interpolation reconstruction method

Country Status (1)

Country Link
CN (1) CN103630907B (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106054183A (en) * 2016-04-29 2016-10-26 深圳市太赫兹科技创新研究院有限公司 Three-dimensional image reconstruction method and device based on synthetic aperture radar imaging
CN107102324A (en) * 2017-04-28 2017-08-29 华讯方舟科技有限公司 A kind of close shot microwave imaging method and system
CN108828577A (en) * 2018-04-16 2018-11-16 北京无线电测量研究所 A kind of imaging method of radar, device, system and storage medium
CN110736984A (en) * 2019-09-24 2020-01-31 西南交通大学 Interpolation-free three-dimensional active millimeter wave imaging method and system and imaging equipment

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2148217A1 (en) * 2003-10-30 2010-01-27 Battelle Memorial Institute Detection of a concealed object
CN102520402A (en) * 2011-12-30 2012-06-27 北京华航无线电测量研究所 Multi-angle fast imaging display method for cylinder array surface three-dimension imaging system
CN102540183A (en) * 2010-12-14 2012-07-04 中国科学院电子学研究所 Three-dimensional microwave imaging method based on cylinder geometry
CN102565796A (en) * 2011-12-30 2012-07-11 北京华航无线电测量研究所 Imaging method for cylindrical array surface three-dimensional imaging system
US20120274505A1 (en) * 2011-04-27 2012-11-01 Lockheed Martin Corporation Automated registration of synthetic aperture radar imagery with high resolution digital elevation models
CN103323854A (en) * 2012-03-22 2013-09-25 中国科学院电子学研究所 Doppler beam sharpening imaging method and device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2148217A1 (en) * 2003-10-30 2010-01-27 Battelle Memorial Institute Detection of a concealed object
CN102540183A (en) * 2010-12-14 2012-07-04 中国科学院电子学研究所 Three-dimensional microwave imaging method based on cylinder geometry
US20120274505A1 (en) * 2011-04-27 2012-11-01 Lockheed Martin Corporation Automated registration of synthetic aperture radar imagery with high resolution digital elevation models
CN102520402A (en) * 2011-12-30 2012-06-27 北京华航无线电测量研究所 Multi-angle fast imaging display method for cylinder array surface three-dimension imaging system
CN102565796A (en) * 2011-12-30 2012-07-11 北京华航无线电测量研究所 Imaging method for cylindrical array surface three-dimensional imaging system
CN103323854A (en) * 2012-03-22 2013-09-25 中国科学院电子学研究所 Doppler beam sharpening imaging method and device

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
年丰等: "近场C-SAR成像系统关键技术研究", 《现代防御技术》, vol. 40, no. 6, 31 December 2012 (2012-12-31) *
翟楠希等: "基于NUFFT的近场雷达三维成像算法", 《计算机工程与应用》, vol. 47, no. 8, 31 December 2011 (2011-12-31), pages 255 - 258 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106054183A (en) * 2016-04-29 2016-10-26 深圳市太赫兹科技创新研究院有限公司 Three-dimensional image reconstruction method and device based on synthetic aperture radar imaging
CN107102324A (en) * 2017-04-28 2017-08-29 华讯方舟科技有限公司 A kind of close shot microwave imaging method and system
CN108828577A (en) * 2018-04-16 2018-11-16 北京无线电测量研究所 A kind of imaging method of radar, device, system and storage medium
CN110736984A (en) * 2019-09-24 2020-01-31 西南交通大学 Interpolation-free three-dimensional active millimeter wave imaging method and system and imaging equipment

Also Published As

Publication number Publication date
CN103630907B (en) 2016-09-14

Similar Documents

Publication Publication Date Title
CN105954750B (en) The non-sparse scene imaging method of stripmap synthetic aperture radar based on compressed sensing
CN102854507B (en) Imaging method of bistatic SAR (synthetic aperture radar) based on GPU (graphics processing unit) back projection
CN103630907A (en) Interpolation-free reconstruction method for near-distance active millimeter-wave cylindrical scanning imaging system
CN106680796B (en) Plane holographic array target three-dimensional surface reconstructing method based on frequency interference
CN110109100B (en) Multi-baseline least square phase unwrapping method based on quality map weighting
CN103142228A (en) Compressed sensing magnetic resonance fast imaging method
CN104833974A (en) SAR imaging quick backward projection method based on image spectrum compression
CN103018741A (en) Interferometric synthetic aperture radar (InSAR) imaging and flat ground removing integral method based on back projection
CN110146884A (en) Synthetic aperture radar chromatography imaging method is regarded on front side of motor-driven track
Yao et al. Applying convolutional neural networks for the source reconstruction
CN107942326B (en) Two-dimensional active millimeter wave imaging method with high universality
CN103076608B (en) Contour-enhanced beaming-type synthetic aperture radar imaging method
CN106872977A (en) A kind of chromatography SAR three-D imaging methods based on the weak orthogonal matching pursuit of segmentation
CN102183763A (en) Polar format algorithm (PFA) wave-front bending error compensating method applicable for complex radar track condition
CN113608218B (en) Frequency domain interference phase sparse reconstruction method based on back projection principle
CN117129994B (en) Improved backward projection imaging method based on phase compensation nuclear GNSS-SAR
CN108646242B (en) Multi-sub-band radar data fusion imaging method for complex target
Marks et al. Near‐field multistatic radar reconstruction with stretched‐phase Fourier accelerated multistatic imaging
CN116679265A (en) SAR time domain rapid echo simulation method suitable for use in topography fluctuation scene
Yao et al. Source reconstruction method based on machine learning algorithms
CN104076359A (en) Multistage back-projection synthetic aperture radar imaging method based on geometric correction
Austin et al. Wie-angle sarse 3D synthetic aerture radar imaging for nonlinear flight paths
Li et al. Design of High-performance Super-resolution Spaceborne SAR Real-time Imaging Chip
Wu et al. An efficient method on ISAR image reconstruction via norm regularization
CN111722224A (en) Keystone transformation-based three-dimensional imaging method for ground-based synthetic aperture radar

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant