CN109738890B - Method for generating ground range map based on missile-borne bistatic SAR range-Doppler image - Google Patents
Method for generating ground range map based on missile-borne bistatic SAR range-Doppler image Download PDFInfo
- Publication number
- CN109738890B CN109738890B CN201811646045.0A CN201811646045A CN109738890B CN 109738890 B CN109738890 B CN 109738890B CN 201811646045 A CN201811646045 A CN 201811646045A CN 109738890 B CN109738890 B CN 109738890B
- Authority
- CN
- China
- Prior art keywords
- lattice point
- distance
- grid
- point
- missile
- 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
Landscapes
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention discloses a method for generating a ground distance map based on a missile-borne bistatic SAR range-Doppler image, which comprises the following steps of: generating a ground distance graph grid; optionally selecting a certain lattice point in the ground distance map grid, and calculating the bistatic distance sum and the Doppler frequency of the lattice point; calculating the preliminary projection position of the lattice point in the slope distance graph; calculating a backscattering value of the preliminary projection position to obtain an accurate projection value; and traversing the grid points in the ground distance map, and repeating the steps from S2 to S4 until the traversal is completed, relating to the technical field of SAR imaging. The method is closely combined with the characteristics of the missile-borne double-base SAR platform, does not depend on specific flight configuration, generates the ground distance map of the missile-borne double-base SAR by constructing the projection relation between the ground point and the point on the slope distance map under the missile-borne general double-base SAR imaging configuration, and has the advantages of convenient processing and small calculation amount.
Description
Technical Field
The invention relates to the technical field of SAR imaging, in particular to a method for generating a ground distance map based on a missile-borne bistatic SAR range-Doppler image.
Background
SAR (synthetic aperture radar) is a modern high-resolution microwave remote sensing imaging radar all day long and all weather, and plays an increasingly important role in the fields of military reconnaissance, topographic mapping, vegetation analysis, marine and hydrological observation, environmental and disaster monitoring, resource exploration, crustal micro-deformation detection and the like. Due to the fact that the transmitting and receiving platforms are arranged separately, the bistatic SAR can achieve the effect that a transmitting bomb irradiates a target area to provide azimuth Doppler high resolution, and a receiving bomb can achieve the forward-looking imaging capability of the target area, so that high-resolution two-dimensional radar image end guidance can be achieved for a target scene.
In the missile-borne bistatic SAR, a receiving and transmitting platform flies at high maneuvering speed, the distance and Doppler information of a ground target point are provided by a launching bomb and a receiving bomb together, an imaging echo model is complex, a range Doppler image obtained by imaging processing is a range diagram with distance and information and has large geometric distortion, the range diagram is converted into a ground range diagram corresponding to a ground plane, and subsequent image processing and target identification and positioning can be carried out so as to finish SAR imaging guidance. In the existing bistatic SAR ground distance map generation method, the position of a ground point in an oblique distance map is found out by searching, two airplanes are required to keep constant-speed parallel flight, the method cannot be applied to missile-borne general bistatic configuration, and the calculation amount is large; the other type of airborne bistatic SAR imaging model is equivalent to a monostatic SAR imaging model, then projection from an inclined plane to a ground plane is carried out, and the airborne bistatic SAR imaging model is only suitable for a specific configuration of bistatic parallel flight and still cannot be applied to a missile-borne universal bistatic configuration.
Disclosure of Invention
The invention aims to overcome the defects of the background technology and provide a method for generating a ground distance map based on a missile-borne double-base SAR range Doppler image, which is tightly combined with the characteristics of a missile-borne double-base SAR platform and does not depend on a specific flight configuration.
The invention provides a method for generating a ground distance map based on a missile-borne bistatic SAR range-Doppler image, which comprises the following steps of:
s1, generating a ground distance graph grid;
s2, selecting a certain lattice point in the map grid, and calculating the bibase distance sum and Doppler frequency of the lattice point;
s3, calculating the preliminary projection position of the lattice point in the slope distance graph;
s4, calculating a backscattering value of the preliminary projection position to obtain an accurate projection value;
s5, traversing the grid points in the ground distance map, and repeating S2-S4 until the traversal is completed;
the step S1 specifically includes the following steps:
s11, taking the projection position of the receiving bomb on the ground plane at the image imaging time as the origin, the projection direction of the speed direction on the ground as the X axis, the vertical direction as the Y axis, and the right-hand coordinate system O-XYZ of the component;
s12, the intersection A (x) of the center of the beam of the transmitting-receiving two-station and the XOZ plane0,0,z0) Generating a ground distance map grid with M rows and N columns as a central point according to the imaging requirement image width M multiplied by N and the image geometric resolution rho, wherein the grid length and the grid width are all rho;
the step S2 specifically includes the following steps:
s21, selecting a certain grid point P in the map grid;
s22, respectively calculating the distance R between the lattice point P and the projectileTpAnd the distance R between the lattice point P and the receiving bulletRpObtaining the biradical distance and R of the lattice point Pp；
S23, respectively calculating the Doppler frequency f of the projectile to the lattice point PTpAnd the Doppler frequency f of the received shot to the grid point PRpObtaining the Doppler frequency f of the lattice point Pp；
The grid point P is positioned in the ith row and the jth column in the ground distance map grid, and the coordinate of the grid point P is
The coordinates of the projectile are (x)T,HT,zT) The coordinates of the receiving ammunition are (0, H)R0), the distance R between the lattice point P and the projectileTpThe distance R between the lattice point P and the receiving bulletRpDistance of diradical and R of lattice point PpThe calculation formulas of (A) and (B) are respectively as follows:
Rp＝RTp+RRp；
the velocity vector of the projectile is (V)Tx,VTy,VTz) The velocity vector of the receiving projectile is (V)Rx,VRy0), the wavelength of the emission signal is lambda, and the included angle theta between the velocity vector of the projectile and the pointing direction of the beam centerTThe included angle theta between the velocity vector of the receiving bullet and the pointing direction of the beam centerRDoppler frequency f of projectile to lattice point PTpReceiving the Doppler frequency f of the shot to the grid point PRpDoppler frequency f of lattice point PpThe calculation formulas of (A) and (B) are respectively as follows:
fTp＝VTcosθT/λ；
fRp＝VRcosθR/λ；
fp＝fTp+fRp。
on the basis of the above technical solution, the step S3 specifically includes the following steps:
s31, calculating the normalized Doppler frequency f of the lattice point Pp′；
S32, calculating the distance row serial numbers row of the grid points P on the skew distance graph respectivelypAnd the azimuth column number col of the passing point P on the skew distance chartp；
S33, setting the preliminary projection position of the lattice point P on the skew distance graph as the rowpLine, colpAnd (4) columns.
On the basis of the technical scheme, the Doppler frequency of an intersection point A of the center of the beam of the transmitting-receiving dual-station and the XOZ plane is fANormalized Doppler frequency f of lattice point PpThe formula for calculation of' is:
fp′＝fp-fA。
on the basis of the technical scheme, the receiving echo wave gate delay of the receiving bomb is tau, and the sampling frequency is fsPulse width of TpAnd the light speed is C, the distance row number row of the lattice point P on the oblique distance graphpThe azimuth column number col of the grid point P on the skew mappThe calculation formulas of (A) and (B) are respectively as follows:
colp＝fp′Na/fr+Na/2+1。
on the basis of the above technical solution, the step S4 specifically includes the following steps:
s41, selecting a sample;
and S42, performing two-dimensional sinc interpolation according to the selected sample, and calculating the backscattering value of the preliminary projection position to obtain the accurate projection value of the lattice point P.
On the basis of the technical scheme, the sample is a row diagram with a slant rangepRocolpColumn by column, (8 ρ f)sLine (8 ρ f)/CsC) samples in the column range.
Compared with the prior art, the invention has the following advantages:
the method is closely combined with the characteristics of the missile-borne double-base SAR platform, does not depend on specific flight configuration, generates the ground distance map of the missile-borne double-base SAR by constructing the projection relation between the ground point and the point on the slope distance map under the missile-borne general double-base SAR imaging configuration, and has the advantages of convenient processing and small calculation amount.
Drawings
FIG. 1 is a flow chart of a method of generating a range map based on a missile-borne bistatic SAR range-Doppler image in accordance with an embodiment of the present invention;
FIG. 2 is a geometry diagram of a method of generating a range map based on a missile-borne bistatic SAR range-Doppler image in accordance with an embodiment of the present invention;
fig. 3 is a schematic diagram of a geodesic grid of a method for generating a geodesic based on a missile-borne double-base SAR range-doppler image according to an embodiment of the present invention.
Detailed Description
The invention is described in further detail below with reference to the figures and the embodiments.
Referring to fig. 1 to 3, an embodiment of the present invention provides a method for generating a ground range map based on a missile-borne double-base SAR range-doppler image, including the following steps:
s1, generating a ground distance graph grid;
in this embodiment, step S1 specifically includes the following steps:
s11, taking the projection position of the receiving bomb on the ground plane at the image imaging time as the origin, the projection direction of the speed direction on the ground as the X axis, the vertical direction as the Y axis, and the right-hand coordinate system O-XYZ of the component;
s12, the intersection A (x) of the center of the beam of the transmitting-receiving two-station and the XOZ plane0,0,z0) And generating a ground distance map grid with M rows and N columns as a central point according to the imaging requirement image width M multiplied by N and the image geometric resolution rho, wherein the grid length and the grid width are all rho.
S2, selecting a certain lattice point in the map grid, and calculating the bibase distance sum and Doppler frequency of the lattice point;
in this embodiment, step S2 specifically includes the following steps:
s21, selecting a certain grid point P in the map grid;
s22, respectively calculating the distance R between the lattice point P and the projectileTpAnd the distance R between the lattice point P and the receiving bulletRpObtaining the biradical distance and R of the lattice point Pp；
The grid point P is positioned in the ith row and the jth column in the ground distance map grid, and the coordinate of the grid point P is
The coordinates of the projectile are (x)T,HT,zT) The coordinates of the receiving ammunition are (0, H)R0), the distance R between the lattice point P and the projectileTpThe distance R between the lattice point P and the receiving bulletRpDistance of diradical and R of lattice point PpThe calculation formulas of (A) and (B) are respectively as follows:
Rp＝RTp+RRp。
s23, respectively calculating the Doppler frequency f of the projectile to the lattice point PTpAnd the Doppler frequency f of the received shot to the grid point PRpObtaining the Doppler frequency f of the lattice point Pp。
The velocity vector of the projectile is (V)Tx,VTy,VTz) The velocity vector of the receiving projectile is (V)Rx,VRy0), the wavelength of the emission signal is lambda, and the included angle theta between the velocity vector of the projectile and the pointing direction of the beam centerTThe included angle theta between the velocity vector of the receiving bullet and the pointing direction of the beam centerRDoppler frequency f of projectile to lattice point PTpReceiving the Doppler frequency f of the shot to the grid point PRpDoppler frequency f of lattice point PpThe calculation formulas of (A) and (B) are respectively as follows:
fTp＝VTcosθT/λ；
fRp＝VRcosθR/λ；
fp＝fTp+fRp。
s3, calculating the preliminary projection position of the lattice point in the slope distance graph;
in this embodiment, step S3 specifically includes the following steps:
s31, calculating the normalized Doppler frequency f of the lattice point Pp′；
The Doppler frequency of an intersection point A of the center of the wave beams of the transmitting and receiving double stations and the XOZ plane is fANormalized Doppler frequency f of lattice point PpThe formula for calculation of' is:
fp′＝fp-fA。
s32, calculating the distance row serial numbers row of the grid points P on the skew distance graph respectivelypAnd the azimuth column number col of the passing point P on the skew distance chartp；
The receiving echo wave gate delay of the receiving bomb is tau, and the sampling frequency is fsPulse width of TpAnd the light speed is C, the distance row number row of the lattice point P on the oblique distance graphpThe azimuth column number col of the grid point P on the skew mappThe calculation formulas of (A) and (B) are respectively as follows:
colp＝fp′Na/fr+Na/2+1。
s33, setting the preliminary projection position of the lattice point P on the skew distance graph as the rowpLine, colpAnd (4) columns.
S4, calculating a backscattering value of the preliminary projection position to obtain an accurate projection value;
in this embodiment, step S4 specifically includes the following steps:
s41, selecting a sample;
and S42, performing two-dimensional sinc interpolation according to the selected sample, and calculating the backscattering value of the preliminary projection position to obtain the accurate projection value of the lattice point P.
The key of the interpolation is to select the size of an interpolated sample, if the sample is too large, the calculated amount is large, and if the sample is too small, the calculation is not accurate; in this embodiment, preferably, the sample is a row in a slope diagrampRocolpColumn by column, (8 ρ f)sLine (8 ρ f)/CsA sample in the column of/C); the interval size of the ground distance graph grid is geometric resolution rho, the resolution of the target of the oblique distance graph point is usually 1-2 times of rho, therefore, in order to ensure the accuracy of interpolation, the main lobe and the adjacent side lobe of the point in the oblique distance graph are calculated as interpolation samples, the sample width is selected to be 8 rho multiplied by 8 rho, and the distance line spacing of the oblique distance graph is C/fsAnd the number of sample points corresponding to the 8 rho width is 8 rho fsC, i.e. selecting the slope diagram rowpRocolpColumn by column, (8 ρ f)sLine (8 ρ f)/CsA sample in the column of/C); the influence of the energy of the main lobe and the first side lobe of the point target is considered during interpolation, and the processed data amount is small. Meanwhile, the interpolation precision and the processing efficiency are considered.
And S5, traversing the grid points in the ground distance graph, and repeating S2-S4 until the traversal is completed.
Various modifications and variations of the embodiments of the present invention may be made by those skilled in the art, and they are also within the scope of the present invention, provided they are within the scope of the claims of the present invention and their equivalents.
What is not described in detail in the specification is prior art that is well known to those skilled in the art.
Claims (6)
1. A method for generating a ground range map based on a missile-borne double-base SAR range-Doppler image is characterized by comprising the following steps:
s1, generating a ground distance graph grid;
s2, selecting a certain lattice point in the map grid, and calculating the bibase distance sum and Doppler frequency of the lattice point;
s3, calculating the preliminary projection position of the lattice point in the slope distance graph;
s4, calculating a backscattering value of the preliminary projection position to obtain an accurate projection value;
s5, traversing the grid points in the ground distance map, and repeating S2-S4 until the traversal is completed;
the step S1 specifically includes the following steps:
s11, taking the projection position of the receiving bomb on the ground plane at the image imaging time as the origin, the projection direction of the speed direction on the ground as the X axis, the vertical direction as the Y axis, and the right-hand coordinate system O-XYZ of the component;
s12, the intersection A (x) of the center of the beam of the transmitting-receiving two-station and the XOZ plane0,0,z0) Generating a ground distance map grid with M rows and N columns as a central point according to the imaging requirement image width M multiplied by N and the image geometric resolution rho, wherein the grid length and the grid width are all rho;
the step S2 specifically includes the following steps:
s21, selecting a certain grid point P in the map grid;
s22, respectively calculating the distance R between the lattice point P and the projectileTpAnd the distance R between the lattice point P and the receiving bulletRpObtaining the biradical distance and R of the lattice point Pp；
S23, respectively calculating the Doppler frequency f of the projectile to the lattice point PTpAnd the Doppler frequency f of the received shot to the grid point PRpObtaining the Doppler frequency f of the lattice point Pp；
The grid point P is positioned in the ith row and the jth column in the ground distance map grid, and the coordinate of the grid point P is
The coordinates of the projectile are (x)T,HT,zT) The coordinates of the receiving ammunition are (0, H)R0), the distance R between the lattice point P and the projectileTpThe distance R between the lattice point P and the receiving bulletRpDistance of diradical and R of lattice point PpThe calculation formulas of (A) and (B) are respectively as follows:
Rp＝RTp+RRp；
the velocity vector of the projectile is (V)Tx,VTy,VTz) The velocity vector of the receiving projectile is (V)Rx,VRy0), the wavelength of the emission signal is lambda, and the included angle theta between the velocity vector of the projectile and the pointing direction of the beam centerTThe included angle theta between the velocity vector of the receiving bullet and the pointing direction of the beam centerRDoppler frequency f of projectile to lattice point PTpReceiving the Doppler frequency f of the shot to the grid point PRpDoppler frequency f of lattice point PpThe calculation formulas of (A) and (B) are respectively as follows:
fTp＝VTcosθT/λ；
fRp＝VRcosθR/λ；
fp＝fTp+fRp。
2. the method for generating a ground range map based on a missile-borne double-base SAR range-Doppler image as claimed in claim 1, wherein the step S3 specifically comprises the following steps:
s31, calculating the normalized Doppler frequency f of the lattice point Pp′；
S32, calculating the distance row serial numbers row of the grid points P on the skew distance graph respectivelypAnd the azimuth column number col of the passing point P on the skew distance chartp；
S33, setting the preliminary projection position of the lattice point P on the skew distance graph as the rowpLine, colpAnd (4) columns.
3. The method for generating a ground range map based on a missile-borne bistatic SAR range-doppler image as claimed in claim 2, wherein the doppler frequency of the intersection a of the centers of the beams of said transceiver bistatic stations and the XOZ plane is fANormalized Doppler frequency f of lattice point PpThe formula for calculation of' is:
fp′＝fp-fA。
4. the method of generating a range map based on a missile-borne bistatic SAR range-Doppler image in claim 3, wherein the receive-missile echo gate delay is τ and the sampling frequency is fsPulse width of TpAnd the light speed is C, the distance row number row of the lattice point P on the oblique distance graphpThe azimuth column number col of the grid point P on the skew mappThe calculation formulas of (A) and (B) are respectively as follows:
colp＝fp′Na/fr+Na/2+1。
5. the method for generating a range map based on a missile-borne double-base SAR range-Doppler image as claimed in claim 4, wherein the step S4 specifically comprises the following steps:
s41, selecting a sample;
and S42, performing two-dimensional sinc interpolation according to the selected sample, and calculating the backscattering value of the preliminary projection position to obtain the accurate projection value of the lattice point P.
6. The method of generating a range map based on a missile-borne bistatic SAR range-Doppler image as recited in claim 5, wherein: the sample is a slope diagram rowpRocolpColumn by column, (8 ρ f)sLine (8 ρ f)/CsC) samples in the column range.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811646045.0A CN109738890B (en) | 2018-12-29 | 2018-12-29 | Method for generating ground range map based on missile-borne bistatic SAR range-Doppler image |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811646045.0A CN109738890B (en) | 2018-12-29 | 2018-12-29 | Method for generating ground range map based on missile-borne bistatic SAR range-Doppler image |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109738890A CN109738890A (en) | 2019-05-10 |
| CN109738890B true CN109738890B (en) | 2021-04-27 |
Family
ID=66362771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811646045.0A Active CN109738890B (en) | 2018-12-29 | 2018-12-29 | Method for generating ground range map based on missile-borne bistatic SAR range-Doppler image |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109738890B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110161503B (en) * | 2019-06-24 | 2021-07-02 | 杭州电子科技大学 | Short-range and wide-range SAR high-resolution imaging method based on three-dimensional equidistant circle model |
| CN112415513B (en) * | 2020-10-26 | 2022-11-25 | 湖北航天技术研究院总体设计所 | Missile-borne bistatic forward-looking SAR (synthetic aperture radar) receiving missile target identification and positioning method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107092014A (en) * | 2017-06-27 | 2017-08-25 | 西安电子科技大学 | A kind of optimization method of the biradical Forward-looking SAR Warship Target Positioning of missile-borne |
| CN108490439A (en) * | 2018-03-20 | 2018-09-04 | 西安电子科技大学 | Bistatic arbitrary configuration SAR imaging methods based on equivalent oblique distance |
-
2018
- 2018-12-29 CN CN201811646045.0A patent/CN109738890B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107092014A (en) * | 2017-06-27 | 2017-08-25 | 西安电子科技大学 | A kind of optimization method of the biradical Forward-looking SAR Warship Target Positioning of missile-borne |
| CN108490439A (en) * | 2018-03-20 | 2018-09-04 | 西安电子科技大学 | Bistatic arbitrary configuration SAR imaging methods based on equivalent oblique distance |
Non-Patent Citations (2)
| Title |
|---|
| 一种俯冲段子孔径SAR大斜视成像及几何校正方法;李震宇等;《电子与信息学报》;20150831;第37卷(第8期);摘要，第4节 * |
| 弹载曲线轨迹双基SAR反向滤波PFA成像与图像畸变校正算法;邓欢等;《电子与信息学报》;20181130;第40卷(第11期);摘要，第2节，第3.3节，第5节，图1 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109738890A (en) | 2019-05-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106970386B (en) | A kind of optimization method of Radar Doppler beam sharpening | |
| CN102147469B (en) | Imaging method for bistatic forward-looking synthetic aperture radar (SAR) | |
| CN100365429C (en) | Synthetic aperture radar moving target imaging method | |
| CN108427115B (en) | Method for quickly estimating moving target parameters by synthetic aperture radar | |
| CN106597437B (en) | The airborne CW with frequency modulation SAR motion compensation of high frequency and image processing method | |
| CN104749570B (en) | It is a kind of to move constant airborne biradical synthetic aperture radar target localization method | |
| CN103235309B (en) | Near space low-speed platform SAR (Synthetic Aperture Radar) imaging method | |
| CN101526614A (en) | SAR echo rapid simulation method based on sub-aperture and equivalent scatterer | |
| CN106093870A (en) | The SAR GMTI clutter suppression method of hypersonic aircraft descending branch | |
| CN107238824A (en) | Satellite-borne SAR image geometric accurate correction method based on priori dem data | |
| CN107765226A (en) | A kind of SAR satellite radars analogue echoes method, system and medium | |
| CN105182340A (en) | Bistatic forward-looking SAR (Synthetic Aperture Radar) motion compensation method | |
| CN107015199A (en) | A kind of double unmanned plane direction finding time difference positioning methods for considering UAV Attitude angle | |
| CN109738890B (en) | Method for generating ground range map based on missile-borne bistatic SAR range-Doppler image | |
| CN116500626B (en) | Multi-receiving array element data receiving-transmitting combination conversion method | |
| Blacknell et al. | The prediction of geometric distortions in airborne synthetic aperture radar imagery from autofocus measurements | |
| Saeedi | Feasibility study and conceptual design of missile-borne synthetic aperture radar | |
| CN108107427A (en) | Airborne/missile-borne array radar forword-looking imaging method based on super resolution technology | |
| CN110389339A (en) | A kind of radar DBS imaging geometry distortion correction and subgraph joining method | |
| CN112505694B (en) | Space target imaging method of on-orbit SAR satellite | |
| RU2483324C1 (en) | Method for aircraft navigation on radar images of earth's surface | |
| CN106526544B (en) | MIMOSAR clutter suppression method based on hypersonic platform | |
| JP2015052549A (en) | Synthetic aperture radar system and method of image processing thereof | |
| RU2379707C1 (en) | Method for surface observation by onboard radio-ir-radar connected with radar | |
| US6664917B2 (en) | Synthetic aperture, interferometric, down-looking, imaging, radar system |
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 |