CN108562899B - High-resolution polarization SAR target image rapid simulation method - Google Patents

High-resolution polarization SAR target image rapid simulation method Download PDF

Info

Publication number
CN108562899B
CN108562899B CN201810362394.3A CN201810362394A CN108562899B CN 108562899 B CN108562899 B CN 108562899B CN 201810362394 A CN201810362394 A CN 201810362394A CN 108562899 B CN108562899 B CN 108562899B
Authority
CN
China
Prior art keywords
surface element
light
calculating
matrix
radar
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
Application number
CN201810362394.3A
Other languages
Chinese (zh)
Other versions
CN108562899A (en
Inventor
张磊
李青伟
刘宏伟
万欣
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.)
Xidian University
Original Assignee
Xidian University
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 Xidian University filed Critical Xidian University
Priority to CN201810362394.3A priority Critical patent/CN108562899B/en
Publication of CN108562899A publication Critical patent/CN108562899A/en
Application granted granted Critical
Publication of CN108562899B publication Critical patent/CN108562899B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • G01S13/9005—SAR image acquisition techniques with optical processing of the SAR signals
    • 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
    • G01S13/9076—Polarimetric features in SAR

Abstract

The invention discloses a high-resolution polarimetric SAR target image rapid simulation method, which mainly solves the problems that the existing polarimetric SAR image is high in acquisition difficulty, high in cost and low in speed, and the polarimetric characteristic is not considered in the conventional ray tracing image simulation. The method comprises the following implementation steps: constructing a target scene model, and setting radar parameters; determining the position of the irradiated surface element according to the distance between each surface element of the target on the light path and the radar, and calculating a single scattering matrix and a secondary scattering matrix of the surface element; calculating the single scattering energy of the surface element according to the incident light and the single scattering matrix; calculating the secondary scattering energy of the surface element according to the incident light and the secondary scattering matrix; calculating total scattering energy according to the single scattering energy and the secondary scattering energy; and imaging the target scene according to the total scattering energy. The method can simply, conveniently and quickly acquire the relatively real polarized SAR image, reduces the cost and can be used for target identification.

Description

High-resolution polarization SAR target image rapid simulation method
Technical Field
The invention belongs to the technical field of radars, and particularly relates to an SAR target image simulation method which can be used for radar target identification analysis library building.
Background
The synthetic aperture radar SAR is a radar that obtains a high-resolution image using microwaves, and has the advantages of all-time and all-weather. It skillfully utilizes pulse compression technology, synthetic aperture technology and some signal processing methods to obtain double high-resolution images in the azimuth direction and the distance direction by using a real small-aperture antenna. In the azimuth direction, the SAR utilizes a small-aperture antenna to synthesize a large aperture through the continuous movement of a radar, so that the beam width is reduced, and the azimuth resolution is improved; in the distance direction, the radar transmits a large-bandwidth chirp signal, and after a target echo is received, the echo is subjected to pulse compression, so that the resolution in the distance direction is high.
With the continuous development of the SAR technology, the SAR simulation technology has also made good progress. The SAR simulation technology is a technology for simulating the working process of SAR by using a computer to finally realize imaging. SAR imaging is mainly related to the reflection characteristics of the target and the SAR system itself, and since many of the steps from signal transmission, signal reception, and processing of the received signal to final imaging need to be actually measured and implemented in the aircraft, the resulting image is subject to large and uncontrollable errors due to the influence of radar carrier motion, radar system hardware, and signal processing techniques, see [ litjin. University of electronic technology 1-65 ]. In addition, the cost required for acquiring SAR experimental data is high, so that a computer is utilized to combine a target scattering characteristic, an SAR imaging principle and an electromagnetic calculation simulation technology to generate an SAR image, which plays an important role in the research of SAR system design, imaging verification, target characteristic analysis and the like, and simulation is an economic, effective and important method for SAR imaging research. The method can greatly reduce the cost of the actual flight test, and the image introduction actual conditions are comprehensive and controllable, so that the research time and the economic expenditure can be saved.
In the conventional ray tracing analog SAR imaging, the emission of electromagnetic waves is regarded as the irradiation of one ray, and imaging is performed according to the propagation path and the magnitude of scattering energy by simulating scattering and reflection of light. However, in the imaging process, because the vector propagation polarization characteristic of the actually emitted electromagnetic wave is not considered, the generated image cannot reflect the polarization scattering characteristic of the target, so that the image obtained by simulation has a larger difference from the SAR image recorded in different actual polarizations, and the image cannot be used for target characteristic analysis and identification of the polarized SAR.
Disclosure of Invention
The invention aims to provide a high-resolution rapid simulation method of a polarized SAR target image aiming at the defects of the prior art, so as to reduce the difference between the simulated image and the actual polarized SAR image, ensure that the simulated image is more real, and can be used for target identification of the polarized SAR.
The technical scheme of the invention is as follows: forming a target scene by the small triangular surface elements, and irradiating the target scene by using light with polarization characteristics; the method comprises the following steps of determining the position of a small triangular surface element of an irradiated target by utilizing a ray tracing algorithm, calculating a backscattering matrix at the triangular surface element according to the irradiation direction of rays and the posture of the small triangular surface element, and further imaging by backscattering energy of each irradiated surface element, wherein the method comprises the following implementation steps:
(1) parameter setting
Setting the height h of an airborne radar, the flying speed v of the airborne and the minimum light irradiation angle thetaminAzimuth resolution delta A, range resolution delta R, frequency omega of electromagnetic wave transmitted by radar, surface dielectric constant epsilon of target, amplitude E of electromagnetic wave in horizontal polarization directionihAnd amplitude E of electromagnetic wave in vertical polarization directioniv；
(2) Constructing a target scene 3D model combined by triangular surface elements, introducing the model into commercial matlab software, extracting a coordinate matrix T of a vertex of the triangular surface element of the 3D model, and obtaining a maximum azimuth A of the radar according to the vertex coordinate matrix T and the radar height hmaxMinimum value AminMaximum value of slope distance RmaxAnd minimum value of slope distance Rmin；
(3) Calculating the sampling point number K of the radar in the azimuth direction and the sampling point number N of the distance direction according to the parameters obtained in the step (2);
(4) controlling the radar to do uniform linear motion with the speed v, continuously emitting light rays in the motion process, and irradiating the light rays to a target scene through the radar to form a KxN light ray matrix;
(5) according to the parameters set in the step (1), in the radar motion process, in each light irradiation direction r { l, m } of a position P { l, m }, wherein l is the row number of a light matrix, l is more than or equal to 1 and less than or equal to K, m is the column number of the light matrix, and m is more than or equal to 1 and less than or equal to N;
(6) determining the illuminated triangular bin:
(6a) calculating a light ray E with the number of rows l and the number of columns m according to the parameters in (1) and (5)iThe number zeta of the target surface elements on the propagation path is calculated, and the distance D between the radar and each target surface element on the propagation path is calculatedi；
(6b) Sequencing the a distances from small to large, determining the surface element corresponding to the minimum distance as the surface element irradiated by the light, setting the coordinate of the surface element in the qth row of the vertex coordinate matrix T, wherein q is more than or equal to 1 and less than or equal to K;
(7) the following parameters are calculated from the triangular bins:
(7a) calculating a normal vector g of the surface element according to the number q of the rows where the triangular surface element is located;
(7b) calculating an included angle alpha between the light and the normal vector of the triangular surface element according to the light irradiation direction r { l, m } and the normal vector g of the surface element;
(7c) calculating the Fresnel reflection coefficient R of horizontal polarization according to the dielectric constant epsilon of the target surface in the step (1) and the included angle alpha between the light ray and the normal vector of the surface element in the step (7b)1And vertical polarized Fresnel reflection coefficient R2；
(7d) According to the included angle alpha between the light ray and the normal vector of the surface element in the step (7b), and the horizontal Fresnel reflection coefficient R in the step (7c)1And vertical fresnel reflection coefficient R2Calculating a backscatter matrix S for single scattering of the bins1And a backscatter matrix S of secondary scattering2；
(7e) According to the medium ray E of (6)iAnd backscattering matrix S of single scattering1Calculating the single scattering energy E of the bin1s(l,m)；
(7f) According to incident light EiAnd a secondary scattering matrix S2Calculating the secondary scattering energy E of the bin2s(l,m)；
(8) Calculating the single scattering energy E of all KXN rays according to the steps (6) to (7)1sAnd secondary scattered energy E2s；
(9) The single scattering energy E1sAnd secondary scattered energy E2sThe sum is used as a pixel point matrix EsAnd drawing a high-resolution polarized SAR image by using commercial software matlab.
The invention has the following advantages
1) Because the polarization characteristic of the light is added when the SAR image simulation is carried out by utilizing the ray tracing, the simulation process has more authenticity, and the formed image is more real.
2) The invention utilizes the polarization characteristic of light, and the obtained image reflects the polarization characteristic of the target, thereby providing data support for polarized SAR target identification and polarized SRA image feature learning.
Drawings
FIG. 1 is a flow chart of an implementation of the present invention;
FIG. 2 is a graph of simulation results of the present invention target under horizontal polarization;
FIG. 3 is a graph of simulation results of the present invention target under vertical polarization.
Detailed Description
The embodiments and effects of the present invention will be further explained with reference to the accompanying drawings:
the invention aims at the situation that an airborne radar is in a front side view imaging mode, the working mode of an airborne machine is 'one step and one stop', the situation that the flying environment of the airborne machine is an ideal situation and abnormal jitter does not exist during flying is assumed, and a target scene model is formed by combining a small triangle.
Referring to fig. 1, the fast simulation method for the high-resolution polarized SAR target image of the present invention comprises the following steps:
step 1: and setting radar parameters and importing a target model.
1.1) setting the height h of an airborne radar, the flying speed v of the airborne radar and the minimum light irradiation angle thetaminAzimuth resolution delta A, range resolution delta R, frequency omega of electromagnetic wave transmitted by radar, surface dielectric constant epsilon of target, amplitude E of electromagnetic wave in horizontal polarization directionihPerpendicular polarization direction electromagnetic wave amplitude Eiv；
1.2) importing the existing target max format model into commercial software 3Dmax, and exporting an obj format model, wherein the obj format model consists of a plurality of triangles;
1.3) importing the obj-format target model into commercial software matlab, and extracting the coordinate matrix T of the vertex of the triangular surface element of the target model.
Step 2: parameters of the target model are calculated.
2.1) comparing the values of the orientation directions represented in the coordinate matrix T to obtain the maximum value A of the target model in the orientation directionmaxAnd minimum value A in the azimuth directionmin；
2.2) comparing the values of the distance direction expressed in the coordinate matrix T to obtain the maximum value d of the target model in the distance directionmaxAnd the minimum value d of the distance directionminAccording to dmaxAnd dminCalculating and storing maximum value R of radar slope distancemaxMinimum value RminRespectively as follows:
Figure BDA0001636292070000041
Figure BDA0001636292070000042
and step 3: and calculating the number of sampling points of the azimuth direction and the range direction of the radar to form a KxN light matrix.
3.1) maximum value A of the target model obtained according to (2.1) in azimuth directionmaxAnd minimum value A in the azimuth directionminAnd calculating the number K of sampling points as follows:
Figure BDA0001636292070000043
3.2) maximum value A of radar slant distance obtained according to (2.2)maxAnd radar slant distance minimum AminAnd calculating the number N of sampling points in the distance direction as follows:
Figure BDA0001636292070000044
and 3.3) controlling the radar to do uniform linear motion with the speed v, continuously emitting light rays in the motion process, and irradiating the light rays to a target scene through the radar to form a KxN light ray matrix.
And 4, step 4: and calculating the radar position and the light irradiation direction.
Calculating position coordinates P { l, m } of the radar and the irradiation direction r { l, m } of each ray in the imaging simulation process according to the parameters in the step 1:
P{l,m}＝[-h·tan(θmin),Amax-(l-1)·ΔA,h]，
r{l,m}＝[sin(θm),0,-cos(θm)]，，
where l is the number of rows in the ray matrix, m is the number of columns in the ray matrix, θmIs the irradiation angle of the light of the m-th column,
Figure BDA0001636292070000051
θm-1is the light irradiation angle of the m-1 th column, theta1For the light irradiation angle of the first column, θ is taken in this example1＝θmin。
And 5: and determining the illuminated surface element by using the parameters in the step 1.
5.1) calculating the number of upper surface elements zeta of the light path:
from the radar position P { l, m } a ray is taken in the direction r { l, m } to obtain the ray EiIntersection point (x, y, z) with the plane of the triangular bin:
Figure BDA0001636292070000052
Figure BDA0001636292070000053
Figure BDA0001636292070000054
vp1、vp2、vp3three values, v, representing the normal vector of the plane in which the triangular surface element lies1，v2，v3Three vertexes, v, of a triangular bin1(1)、v1(2)、v1(3) Respectively represent v1P (1, l, m), p (2, l, m), p (3, l, m) respectively represent three coordinate values of p { l, m }, and r (1, l, m), r (2, l, m), r (3, l, m) respectively represent three coordinate values of r { l, m };
5.2) judging whether the intersection point is in the triangular surface element:
if the intersection point is inside the triangular surface element, the surface element takes the zeta value as1；
If no intersection point exists or the intersection point is not in the triangular surface element, the surface element is not on the propagation path of the light, and the value of zeta is 0;
5.3) sequentially judging whether the light rays intersect with all the triangular surface elements according to the steps (5.1) and (5.2), and counting the number of zeta values of 1, namely the number zeta of the surface elements to be obtained;
5.4) calculating the distance D between the radar and each surface element on the propagation path according to the number zeta of the target surface elementsi：
Di＝|(p{l,m}-(x,y,z))|，1≤i≤ζ；
5.5) comparing the distances of all the surface elements in the step (5.4), assigning the minimum value to a distance minimum value R, wherein the surface element corresponding to the minimum distance is the irradiated surface element, and obtaining three vertex coordinates of the surface element, namely v1，v2，v3The three coordinates are in the qth row of the coordinate matrix.
Step 6: normal vectors of the illuminated bins are calculated.
According to the three vertexes v of the triangular bin in (5.5)1，v2，v3Calculating a bin normal vector g:
Figure BDA0001636292070000061
and 7: and calculating an included angle alpha between the light ray and the normal vector of the surface element.
Calculating an included angle alpha between the light and the surface element normal vector according to the light irradiation direction r { l, m } and the surface element normal vector in the (6.2) in the step 4:
Figure BDA0001636292070000062
due to the acute included angle, if
Figure BDA0001636292070000063
Then α is pi- α.
And 8: the fresnel reflection coefficients under horizontal and vertical polarization are calculated.
Calculating Fresnel reflection coefficient R under horizontal polarization according to the dielectric constant epsilon of the target surface in the step 1 and the included angle alpha between the light ray and the normal vector of the surface element in the step 71And Fresnel reflection coefficient R under vertical polarization2：
Figure BDA0001636292070000064
Figure BDA0001636292070000065
And step 9: calculating a backscatter matrix S for single scattering1And a backscatter matrix S of secondary scattering2。
According to the included angle alpha between the light and the normal vector of the surface element and the horizontal Fresnel reflection coefficient R1Vertical fresnel reflection coefficient R2Calculating a single-scattering backscattering matrix S1And a backscatter matrix S of secondary scattering2：
Figure BDA0001636292070000066
Figure BDA0001636292070000067
Wherein:
Figure BDA0001636292070000071
Figure BDA0001636292070000072
S1vh＝S1hv，
Figure BDA0001636292070000073
S2hh＝m1[-2R1cosγcos2β]+n1[sin2γsin2β+R2sin2β(1+cos2γ)]，
S2hv＝2n1R2cosγcos2β+m1[sin2γsin2β+R1sin2β(1+cos2γ)]，
S2vh＝S2hv，
S2vv＝2n2R1cosγcos2β+m2[sin2γsin2β+R2sin2β(1+cos2γ)]，
m1＝R2cos2γcos2β-R1sin2β
m2＝-(R1+R2)cosγcosβsinβ
n1＝-(R1+R2)cosγcosβsinβ
n2＝-R1sin2β+R2cos2γcos2β
β＝α，
Figure BDA0001636292070000074
a1、a2、a3three coordinate values of normal vector g of surface element are respectively represented, beta represents included angle between radar motion track and triangular surface element, and gamma tableShowing the perspective of the antenna to the center of the ground track.
Step 10: the scattered energy of the single and second scatterings is calculated.
According to the light ray E in (5.1)iStep 9, a single scattering matrix S1And a secondary scattering matrix S2Calculating the single scattering energy E1s(l, m) and secondary scattered energy E2s(l,m)：
E1s(l,m)＝S1·Ei，
E2s(l,m)＝S2·Ei，
Figure BDA0001636292070000081
R { l, m } is the light irradiation direction, and R is the minimum distance.
Step 11: the single and second scattered energies of all rays were calculated.
Calculating the single scattering energy E of all KXN rays according to the steps 5-101s(l, m) and secondary scattered energy E2s(l, m) to obtain a single-scattering energy matrix E1sAnd a secondary scattered energy matrix E2s。
Step 12: and drawing a polarized SAR image.
The single scattering energy matrix E obtained in step 111sAnd a secondary scattered energy matrix E2sAdding to obtain total scattering energy matrix EsThe total scattered energy matrix EsAnd drawing a high-resolution polarized SAR image by using commercial software matlab as a pixel matrix to complete the simulation.
The invention is further illustrated below by means of a simulation example:
1) setting experiment parameters:
the height h of the airborne radar is 5000m, the speed v of the airborne radar is 100m/s, and the minimum irradiation angle thetamin60 degrees, the frequency of the transmitted electromagnetic wave is 10GHz, the azimuth resolution delta A is 0.1 meter, the range resolution delta R is 0.1 meter, the surface dielectric constant epsilon of the target is 50, and when the horizontal linear polarized wave is transmittedTime, horizontal polarization direction amplitude Eih100m, vertical polarization direction amplitude Eiv0; when transmitting vertically polarized waves, the horizontally polarized directional amplitude Eih0, vertical polarization direction amplitude Eiv＝100m。
2) Simulation scenario
The target scene is T95 tank model on a larger plane, and the scene model size is 17.957m × 19.771m × 3.857 m.
3) Emulated content
And for the scene, carrying out polarized SAR imaging on the scene by using the method of the invention. When the transmitted wave is a horizontally polarized wave, the result is shown in fig. 2; when the transmitted wave is a vertically polarized wave, the result is shown in fig. 3.
As can be seen from fig. 2 and fig. 3, the present invention can accurately image a target scene, and can truly reflect information of the position and the shape of an object, wherein fig. 3 can also reflect the polarization characteristics of the target, and the shading in fig. 3 also reflects the authenticity and the reliability thereof.
The foregoing description is only an example of the present invention and is not intended to limit the invention, so that it will be apparent to those skilled in the art that various modifications and variations in form and detail can be made therein without departing from the spirit and scope of the invention.

Claims (10)

1. The high-resolution polarized SAR target image rapid simulation method comprises the following steps:
(1) parameter setting
Setting the height h of an airborne radar, the flying speed v of the airborne and the minimum light irradiation angle thetaminAzimuth resolution delta A, range resolution delta R, frequency omega of electromagnetic wave transmitted by radar, surface dielectric constant epsilon of target, amplitude E of electromagnetic wave in horizontal polarization directionihAnd amplitude E of electromagnetic wave in vertical polarization directioniv；
(2) Constructing a 3D model of the target scene combined by the triangular surface elements and importing the model into commercial useIn the software matlab, extracting a coordinate matrix T of the vertex of the 3D model triangular surface element, and obtaining the maximum azimuth A of the radar according to the vertex coordinate matrix T and the radar height hmaxMinimum value AminMaximum value of slope distance RmaxAnd minimum value of slope distance Rmin；
(3) Calculating the sampling point number K of the radar in the azimuth direction and the sampling point number N of the distance direction according to the parameters obtained in the step (2);
(4) controlling the radar to do uniform linear motion with the speed v, continuously emitting light rays in the motion process, and irradiating the light rays to a target scene through the radar to form a K multiplied by N light ray matrix;
(5) according to the parameters set in the step (1), in the radar motion process, in the irradiation direction r { l, m } of each light ray at the position P { l, m }, wherein l is the row number in the matrix, l is more than or equal to 1 and less than or equal to K, m is the column number of the matrix, and m is more than or equal to 1 and less than or equal to N;
(6) determining the illuminated triangular bin:
(6a) calculating the light E with the number of rows l and the number of columns m of the light matrix according to the parameters in (1) and (5)iThe number zeta of the target surface elements on the propagation path is calculated, and the distance D between the radar and each target surface element on the propagation path is calculatedi；
(6b) Ordering the a distances from small to large, assigning the minimum value to a distance minimum value R, wherein the surface element corresponding to the minimum distance is the irradiated surface element, setting the coordinate of the surface element in the qth row of a vertex coordinate matrix T, and setting q to be more than or equal to 1 and less than or equal to K;
(7) the following parameters are calculated from the triangular bins:
(7a) calculating a normal vector g of the surface element according to the number q of the rows where the triangular surface element is located;
(7b) calculating an included angle alpha between the light and the normal vector of the triangular surface element according to the light irradiation direction r { l, m } and the normal vector g of the surface element;
(7c) calculating the Fresnel reflection coefficient R of horizontal polarization according to the dielectric constant epsilon of the target surface in the step (1) and the included angle alpha between the light ray and the normal vector of the surface element in the step (7b)1And vertical polarized Fresnel reflection coefficient R2；
(7d) According to the angle alpha between the light ray in (7b) and the normal vector of the surface element in (7c)Horizontally polarized fresnel reflection coefficient R1And vertical polarized Fresnel reflection coefficient R2Calculating a backscatter matrix S for single scattering of the bins1And a backscatter matrix S of secondary scattering2；
(7e) According to the medium ray E of (6)iBackscatter matrix S of single scattering in (7d) and (7d)1Calculating the single scattering energy E of the bin1s(l,m)；
(7f) According to incident light EiAnd a secondary scattering matrix S2Calculating the secondary scattering energy E of the bin2s(l,m)；
(8) Calculating the single scattering energy E of all KXN rays according to the steps (6) to (7)1sAnd secondary scattered energy E2s；
(9) The single scattering energy E1sAnd secondary scattered energy E2sThe sum is used as a pixel point matrix EsAnd drawing a high-resolution polarized SAR image by using commercial software matlab.
2. The method of claim 1, wherein: calculating the sampling point number K of the radar azimuth direction and the sampling point number N of the distance direction in the step (3) according to the following formula:
Figure FDA0003142896990000021
Figure FDA0003142896990000022
3. the method of claim 1, wherein: in the step (5), the irradiation directions r { l, m } of the light rays at the positions P { l, m } in the radar motion process are calculated according to the following formula:
P{l,m}＝[-h·tan(θmin),Amax-(l-1)·ΔA,h]，
r{l,m}＝[sin(θm),0,-cos(θm)]，
wherein, thetamIs the irradiation angle of the light of the m-th column,
Figure FDA0003142896990000023
θm-1is the light irradiation angle of the m-1 th column,
θ1is the light irradiation angle of the first column, theta1＝θmin。
4. The method of claim 1, wherein: calculating a ray E with the number of rows l and the number of columns m in step (6a)iThe number zeta of the target surface elements on the propagation path is calculated, and the distance R between the radar and each surface element on the propagation path is calculatediThe method comprises the following steps:
(6a1) and taking a ray along the direction r { l, m } from the radar position P { l, m }, and solving the intersection point (x, y, z) of the ray and the plane of the triangular bin:
Figure FDA0003142896990000031
Figure FDA0003142896990000032
Figure FDA0003142896990000033
vp1、vp2、vp3three values, v, representing the normal vector of the plane in which the triangular surface element lies1(1)、v1(2)、v1(3) Respectively represent v1P (1, l, m), p (2, l, m), p (3, l, m) respectively represent three coordinate values of p { l, m }, and r (1, l, m), r (2, l, m), r (3, l, m) respectively represent three coordinate values of r { l, m };
(6a2) judging whether the intersection point is in the triangular surface element:
if the intersection is inside a triangular bin, that bin is on the propagation path of this ray, the intersection marker is 1,
if no intersection point exists or the intersection point is not in the triangular surface element, the surface element is not on the propagation path of the light, and the intersection marker is 0;
(6a3) sequentially judging whether the light rays intersect with all the triangular surface elements according to the steps (6a1) and (6a2), and counting the number of the intersection markers which are obtained as 1, namely the number zeta of the object surface elements;
(6a4) according to the number zeta of the target surface elements, the distance D between the radar and each surface element on the propagation path is calculated according to the following formulai：
Di＝|(p{l,m}-(x,y,z))|，1≤i≤ζ。
5. The method of claim 1, wherein: in the step (7a), a bin normal vector g is calculated according to the number q of the rows where the triangular bin is located, and the calculation is carried out according to the following formula:
Figure FDA0003142896990000034
wherein v is1，v2，v3Three vertexes of the qth row of the vertex matrix are respectively.
6. The method of claim 1, wherein: in the step (7b), according to the light irradiation direction r { l, m } and the normal vector g of the surface element, the included angle alpha between the light and the normal vector of the triangular surface element is calculated according to the following formula:
Figure FDA0003142896990000041
r (: l, m) represents the coordinate value of the light direction r { l, m }.
7. The method of claim 1, wherein: according to the dielectric constant of the target surface in step (7c)Calculating the horizontal polarization Fresnel reflection coefficient R by the number epsilon and the included angle alpha between the light and the normal vector of the surface element1And vertical polarization Fresnel reflection coefficient R2Calculated according to the following formula:
Figure FDA0003142896990000042
Figure FDA0003142896990000043
8. the method of claim 1, wherein: in the step (7d), according to the included angle alpha between the light and the surface element normal vector and the horizontal Fresnel reflection coefficient R1And vertical fresnel reflection coefficient R2Calculating the backscatter matrix S of the single scattering of the bin1And a backscatter matrix S of secondary scattering2Calculated according to the following formula:
Figure FDA0003142896990000044
Figure FDA0003142896990000045
wherein
Figure FDA0003142896990000046
Figure FDA0003142896990000047
S1vh＝S1hv
Figure FDA0003142896990000048
S2hh＝m1[-2R1cosγcos2β]+n1[sin2γsin2β+R2sin2β(1+cos2γ)]
S2hv＝2n1R2cosγcos2β+m1[sin2γsin2β+R1sin2β(1+cos2γ)]
S2vh＝S2hv
S2vv＝2n2R1cosγcos2β+m2[sin2γsin2β+R2sin2β(1+cos2γ)]
m1＝R2cos2γcos2β-R1sin2β
m2＝-(R1+R2)cosγcosβsinβ
n1＝-(R1+R2)cosγcosβsinβ
n2＝-R1sin2β+R2cos2γcos2β
β＝α
Figure FDA0003142896990000051
(a1,a2,a3) And the coordinate value of a normal vector g of the surface element is shown, beta represents an included angle between a radar motion track and the triangular surface element, and gamma represents a visual angle from the antenna to the ground track center.
9. The method of claim 1, wherein: according to the light E in the step (7E)iAnd a single-scattered backscatter matrix S1Calculating the single scattering energy E of the bin1s(l, m) calculated as follows:
E1s(l,m)＝S1·Ei，
wherein
Figure FDA0003142896990000052
R { l, m } is the light irradiation direction, and R is the minimum distance.
10. The method of claim 1, wherein: in step (7f), according to the incident ray EiAnd a secondary scattering matrix S2Calculating the secondary scattering energy E of the bin2s(l, m) calculated as follows:
E2s(l,m)＝S2·Ei，
wherein
Figure FDA0003142896990000053
R { l, m } is the light irradiation direction, and R is the minimum distance.
CN201810362394.3A 2018-04-20 2018-04-20 High-resolution polarization SAR target image rapid simulation method Active CN108562899B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810362394.3A CN108562899B (en) 2018-04-20 2018-04-20 High-resolution polarization SAR target image rapid simulation method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810362394.3A CN108562899B (en) 2018-04-20 2018-04-20 High-resolution polarization SAR target image rapid simulation method

Publications (2)

Publication Number Publication Date
CN108562899A CN108562899A (en) 2018-09-21
CN108562899B true CN108562899B (en) 2021-08-20

Family

ID=63536081

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810362394.3A Active CN108562899B (en) 2018-04-20 2018-04-20 High-resolution polarization SAR target image rapid simulation method

Country Status (1)

Country Link
CN (1) CN108562899B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111123215B (en) * 2019-11-11 2021-11-05 南京长峰航天电子科技有限公司 Multi-channel-based full polarization target implementation system and method
CN112531924B (en) * 2020-10-13 2022-07-15 电子科技大学 Method for rapidly designing antenna array based on maximum wireless energy transmission efficiency

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101236247A (en) * 2008-03-07 2008-08-06 北京航空航天大学 Star-carrying multichannel antenna SAR data channel amplitude and phase error correction platform
CN101329402A (en) * 2008-06-20 2008-12-24 西安电子科技大学 Multi-dimension SAR image edge detection method based on improved Wedgelet
CN101894368A (en) * 2010-07-06 2010-11-24 西安电子科技大学 Method for dividing semi-monitoring SAR image water area based on geodesic distance
CN102901965A (en) * 2012-09-26 2013-01-30 同济大学 Radar imaging method of electrically large size target in ocean clutter environment
CN103983968A (en) * 2014-03-20 2014-08-13 西安电子科技大学 Complete polarization type SAR super-resolution imaging method based on distributed compressed sensing
CN104360317A (en) * 2014-12-09 2015-02-18 中国科学院遥感与数字地球研究所 Method for making linear target all-azimuth angle SAR (Synthetic Aperture Radar) scene matching reference diagram
CN103792521B (en) * 2014-01-17 2016-05-04 西安空间无线电技术研究所 A kind of radar target back scattering analogy method that is subject to Faraday rotation variable effect
CN106680812A (en) * 2016-10-27 2017-05-17 西安空间无线电技术研究所 Microwave correlated imaging simulation method based on analysis surface element
CN107356924A (en) * 2017-07-14 2017-11-17 中国科学院电子学研究所 For the SAR image emulation mode of cavity class formation
CN107561535A (en) * 2017-09-07 2018-01-09 中国科学院电子学研究所 A kind of synthetic aperture radar range ambiguity suppressing method and device
CN107636693A (en) * 2015-03-20 2018-01-26 弗劳恩霍夫应用研究促进协会 Assigned for the relevance scores of artificial neural network

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9019143B2 (en) * 2006-11-30 2015-04-28 Henry K. Obermeyer Spectrometric synthetic aperture radar

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101236247A (en) * 2008-03-07 2008-08-06 北京航空航天大学 Star-carrying multichannel antenna SAR data channel amplitude and phase error correction platform
CN101329402A (en) * 2008-06-20 2008-12-24 西安电子科技大学 Multi-dimension SAR image edge detection method based on improved Wedgelet
CN101894368A (en) * 2010-07-06 2010-11-24 西安电子科技大学 Method for dividing semi-monitoring SAR image water area based on geodesic distance
CN102901965A (en) * 2012-09-26 2013-01-30 同济大学 Radar imaging method of electrically large size target in ocean clutter environment
CN103792521B (en) * 2014-01-17 2016-05-04 西安空间无线电技术研究所 A kind of radar target back scattering analogy method that is subject to Faraday rotation variable effect
CN103983968A (en) * 2014-03-20 2014-08-13 西安电子科技大学 Complete polarization type SAR super-resolution imaging method based on distributed compressed sensing
CN104360317A (en) * 2014-12-09 2015-02-18 中国科学院遥感与数字地球研究所 Method for making linear target all-azimuth angle SAR (Synthetic Aperture Radar) scene matching reference diagram
CN107636693A (en) * 2015-03-20 2018-01-26 弗劳恩霍夫应用研究促进协会 Assigned for the relevance scores of artificial neural network
CN106680812A (en) * 2016-10-27 2017-05-17 西安空间无线电技术研究所 Microwave correlated imaging simulation method based on analysis surface element
CN107356924A (en) * 2017-07-14 2017-11-17 中国科学院电子学研究所 For the SAR image emulation mode of cavity class formation
CN107561535A (en) * 2017-09-07 2018-01-09 中国科学院电子学研究所 A kind of synthetic aperture radar range ambiguity suppressing method and device

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
《Imaging Simulation of polarimetric SAR for a Comprehensive Terrain Scene Using the Mapping and Projection Algorithm》;Feng Xu et.al;《IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING》;20061130;第44卷(第11期);第3219-3234页 *
《建筑物目标高分辨率SAR图像模拟方法》;王国军 等;《遥感技术与应用》;20130831;第28卷(第4期);第594-603页 *

Also Published As

Publication number Publication date
CN108562899A (en) 2018-09-21

Similar Documents

Publication Publication Date Title
CN106772365B (en) A kind of multipath based on Bayes's compressed sensing utilizes through-wall radar imaging method
CN106501802B (en) High-resolution multidimensional synergistic insect is migrated Radar Measurement Instrument
CN107340518B (en) A kind of ISAR radar imaging method under signal deletion
CN105137430B (en) The sparse acquisition of echo of forward sight array SAR a kind of and its three-D imaging method
RU2386143C2 (en) Method of simulating radio signal reflected from spatially distributed dynamic radiophysical scene in real time
CN106872978A (en) A kind of Electromagnetic Modeling emulation mode of complex scene
Kusk et al. Synthetic SAR image generation using sensor, terrain and target models
CN108562899B (en) High-resolution polarization SAR target image rapid simulation method
CN107607951A (en) A kind of SAR image rescattering characteristic simulation method
CN107271977A (en) High-precision SAR echo simulation methods based on mobile driving source FDTD algorithms
Zherdev et al. Object recognition using real and modelled SAR images
CN115128555A (en) Broadband echo signal simulation generation method based on scattering
Watson et al. Non-line-of-sight radar
Chen et al. SAR imaging simulation for urban structures based on analytical models
CN104101869A (en) Ground wave radar moving object simulation modeling method in polar coordinate
Borzov et al. Mathematical modeling and simulation of the input signals of short-range radar systems
GB2283144A (en) Simulated projectile vision
CN111522007A (en) SAR imaging simulation method and system with real scene and target simulation fused
CN113447896B (en) Undulating terrain SAR echo simulation method based on dynamic occlusion judgment
RU2621329C1 (en) Method of radio signal imitation
CN103996214B (en) BP-SAR image reconstruction error analysis method and BP-SAR image reconstruction method
Douchin et al. SE-Workbench-RF: Performant and high-fidelity raw data generation for various radar applications
CN111830500A (en) Radar image simulation method of sea surface ship target based on improved SBR (sequencing batch reactor) rapid imaging technology
Scannapieco et al. Indoor operations by FMCW millimeter wave SAR onboard small UAS: A simulation approach
Gong et al. GRECO Based Fast Prediction of 3D Radar Images for Complex Targets

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