CN114740477A - Interference circumference SAR three-dimensional imaging method and device for complex structure building - Google Patents

Abstract

The invention discloses an interference circumference SAR three-dimensional imaging method and device for a complex structure building, wherein the method comprises the following steps: acquiring a group of sub-aperture image groups corresponding to the antenna phase centers, wherein the sub-aperture image groups are obtained by imaging in a reference height plane according to sub-aperture data of each antenna phase center; performing interference processing on the sub-aperture image group to obtain a winding interference phase; determining a plurality of phase ambiguity numbers according to the winding interference phase, the scene height range and the pre-established relationship between the height difference and the winding interference phase; calculating a plurality of three-dimensional positions under each sub-aperture by using a range-Doppler equation according to a plurality of phase ambiguity numbers; selecting from a plurality of three-dimensional positions under each sub-aperture by using a correlation coefficient algorithm; and performing interference circumference SAR three-dimensional imaging of the complex structure building according to the selected result. The invention effectively reduces the data storage capacity and the calculation amount and improves the imaging efficiency.

Description

Interferometric circular SAR three-dimensional imaging method and device for complex structural buildings

technical field

The invention relates to the technical field of interferometric circular SAR imaging, in particular to an interferometric circular SAR three-dimensional imaging method and device for complex structural buildings.

Background technique

This section is intended to provide a background or context to the embodiments of the invention recited in the claims. The descriptions herein are not admitted to be prior art by inclusion in this section.

The circular synthetic aperture radar can obtain the scattering characteristics of the target in different azimuths through omnidirectional observation, and has the ability of three-dimensional imaging. However, the ability of circular SAR to acquire the highly directional scattering features of highly directional targets is very weak, and its three-dimensional resolution depends on the consistency of target scattering directions.

The interferometric circular SAR three-dimensional imaging method proposes a new imaging mode, which combines the advantages of the circular SAR's omnidirectional observation with the high altitude acquisition capability of the interferometric SAR, which can improve the three-dimensional imaging capability. Interferometric SAR has a high-precision inversion capability. It uses two antennas to repeatedly observe the same area, and makes full use of the phase information carried by the radar echo signal to extract the phase difference between the two echo signals corresponding to the same target. . Therefore, the problem that the 3D resolution of circular SAR depends on the consistency of the target scattering direction can be improved by using the interferometric circular SAR 3D imaging mode. However, for this new mode, the interference phase obtained by conjugate multiplying the image pair is wrapped by the phase period 2π. For buildings with complex structures, the interferometric phase is difficult to unwrap, and it is difficult to obtain the absolute phase. By using the omnidirectional SAR information, there is no need to solve the phase overlay, and the interferometric phase ambiguity number can be directly obtained for 3D imaging of complex structures.

In the prior art, interferometric circular SAR three-dimensional imaging is mostly aimed at simple targets, such as small vehicles, etc., tomography is performed and dual-frequency interference is used to reduce the use of phase unwrapping technology. However, for complex structures, using the above method for interferometric circular SAR 3D imaging requires a huge amount of data storage and calculation, and the 3D imaging efficiency is low.

Therefore, there is an urgent need for an interferometric circular SAR three-dimensional imaging solution for complex structural buildings that can overcome the above problems.

SUMMARY OF THE INVENTION

The embodiment of the present invention provides an interferometric circular SAR three-dimensional imaging method for complex structural buildings, which is used for interferometric circular SAR three-dimensional imaging of complex structural buildings, effectively reduces the amount of data storage and calculation, and improves the imaging efficiency. The method includes:

Obtaining a group of sub-aperture image groups corresponding to the antenna phase centers, the sub-aperture image groups are obtained by imaging on a reference height plane according to the sub-aperture data of each antenna phase center;

performing interference processing on the sub-aperture image group to obtain a winding interference phase;

According to the winding interference phase, the height range of the scene and the relationship between the height difference and the winding interference phase established in advance, determine a plurality of phase ambiguity numbers;

According to the plurality of phase ambiguities, using the range Doppler equation to calculate a plurality of three-dimensional positions under each sub-aperture;

Use a correlation coefficient algorithm to select from a plurality of three-dimensional positions under each sub-aperture;

According to the selected results, the interferometric circular SAR 3D imaging of complex structures is carried out.

The embodiment of the present invention provides an interferometric circular SAR three-dimensional imaging device for complex structural buildings, which is used for interferometric circular SAR three-dimensional imaging of complex structural buildings, effectively reduces the amount of data storage and calculation, and improves the imaging efficiency. The device includes:

a sub-aperture image group obtaining module, configured to obtain a group of sub-aperture image groups corresponding to the antenna phase centers, the sub-aperture image groups are obtained by imaging on a reference height plane according to the sub-aperture data of each antenna phase center;

a sub-aperture image group interference processing module, configured to perform interference processing on the sub-aperture image group to obtain a winding interference phase;

a phase ambiguity number determination module, configured to determine a plurality of phase ambiguity numbers according to the winding interference phase, the height range of the scene and the relationship between the height difference and the winding interference phase established in advance;

A sub-aperture three-dimensional position calculation module, configured to calculate a plurality of three-dimensional positions under each sub-aperture by using the range Doppler equation according to the plurality of phase ambiguities;

a sub-aperture three-dimensional position selection module, used for selecting from a plurality of three-dimensional positions under each sub-aperture by using a correlation coefficient algorithm;

The interferometric circular SAR 3D imaging module is used to perform interferometric circular SAR 3D imaging of complex structures according to the selected results.

An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and running on the processor, when the processor executes the computer program, the interference circle of the above-mentioned complex structure building is realized SAR three-dimensional imaging method.

Embodiments of the present invention further provide a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements the above-mentioned interferometric circular SAR three-dimensional imaging method for complex structures.

An embodiment of the present invention further provides a computer program product, the computer program product includes a computer program, and when the computer program is executed by a processor, realizes the above-mentioned interferometric circular SAR three-dimensional imaging method for a complex structural building.

In the embodiment of the present invention, a group of sub-aperture image groups corresponding to the antenna phase centers are obtained, and the sub-aperture image groups are obtained by imaging on the reference height plane according to the sub-aperture data of each antenna phase center; group to perform interference processing to obtain the winding interference phase; according to the winding interference phase, the height range of the scene and the relationship between the height difference and the winding interference phase established in advance, determine multiple phase ambiguities; according to the multiple phase ambiguities, use The distance Doppler equation calculates multiple three-dimensional positions under each sub-aperture; uses the correlation coefficient algorithm to select from the multiple three-dimensional positions under each sub-aperture; according to the selected results, the interferometric circular SAR three-dimensional imaging. The embodiment of the present invention performs imaging on the reference height plane according to the sub-aperture data of each antenna phase center to obtain a sub-aperture image group, and effectively uses the multi-angle information of each sub-aperture to perform interference processing on the sub-aperture image group to obtain the winding interference phase, No dual-frequency interference or phase unwrapping is required. According to the winding interference phase, the height range of the scene and the relationship between the pre-established height difference and the winding interference phase, multiple phase ambiguities are determined, and the distance Doppler equation is used to calculate multiple three-dimensional positions under each sub-aperture, and then use the correlation coefficient algorithm By selecting from multiple three-dimensional positions under each sub-aperture, the interferometric circular SAR three-dimensional imaging of complex structural buildings can be performed, which effectively reduces the amount of data storage and calculation, and improves the imaging efficiency.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts. In the attached image:

1 is a schematic diagram of an interferometric circular SAR three-dimensional imaging method for complex structural buildings in an embodiment of the present invention;

2 is a schematic diagram of an interferometric circular SAR three-dimensional imaging method for another complex structural building in an embodiment of the present invention;

3 is an interferometric circular SAR geometric model in an embodiment of the present invention;

4 is a schematic diagram of an interferometric circular SAR three-dimensional imaging method for another complex structural building in an embodiment of the present invention;

FIG. 5 is a structural diagram of an interferometric circular SAR three-dimensional imaging device based on a complex structural building in an embodiment of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention more clearly understood, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but not to limit the present invention.

As mentioned above, the existing interferometric circular SAR 3D imaging uses dual-frequency interference to reduce the use of phase unwrapping technology, so that the angle information is not well utilized, and tomography is no longer suitable for complex structures. If the method is used in a large scene, it will cause the problem of excessive calculation and excessive memory.

In order to perform interferometric circular SAR three-dimensional imaging of complex structural buildings, effectively reduce the amount of data storage and calculation, and improve imaging efficiency, an embodiment of the present invention provides an interferometric circular SAR three-dimensional imaging method for complex structural buildings, as shown in FIG. 1 , the Methods can include:

Step 101: Obtain a group of sub-aperture image groups corresponding to the antenna phase centers, where the sub-aperture image groups are obtained by imaging on a reference height plane according to the sub-aperture data of each antenna phase center;

Step 102, performing interference processing on the sub-aperture image group to obtain a winding interference phase;

Step 103: Determine a plurality of phase ambiguities according to the winding interference phase, the height range of the scene and the relationship between the height difference and the winding interference phase established in advance;

Step 104: Calculate a plurality of three-dimensional positions under each sub-aperture by using the range Doppler equation according to the plurality of phase ambiguities;

Step 105, using a correlation coefficient algorithm to select from a plurality of three-dimensional positions under each sub-aperture;

Step 106 , according to the selected result, perform interferometric circular SAR three-dimensional imaging of the complex structural building.

It can be known from FIG. 1 that in the embodiment of the present invention, a group of sub-aperture image groups corresponding to the antenna phase centers are obtained, and the sub-aperture image groups are imaged on the reference height plane according to the sub-aperture data of each antenna phase center. obtain; perform interference processing on the sub-aperture image group to obtain the winding interference phase; according to the winding interference phase, the scene height range and the relationship between the height difference and the winding interference phase established in advance, determine a plurality of phase ambiguity numbers; The multiple phase ambiguity numbers are calculated by using the range Doppler equation to calculate multiple three-dimensional positions under each sub-aperture; the correlation coefficient algorithm is used to select from the multiple three-dimensional positions under each sub-aperture; according to the selected results, Perform interferometric circular SAR 3D imaging of complex structural buildings. The embodiment of the present invention performs imaging on the reference height plane according to the sub-aperture data of each antenna phase center to obtain a sub-aperture image group, and effectively uses the multi-angle information of each sub-aperture to perform interference processing on the sub-aperture image group to obtain the winding interference phase, No dual-frequency interference or phase unwrapping is required. According to the winding interference phase, the height range of the scene and the relationship between the pre-established height difference and the winding interference phase, multiple phase ambiguities are determined, and the distance Doppler equation is used to calculate multiple three-dimensional positions under each sub-aperture, and then use the correlation coefficient algorithm By selecting from multiple three-dimensional positions under each sub-aperture, the interferometric circular SAR three-dimensional imaging of complex structural buildings can be performed, which effectively reduces the amount of data storage and calculation, and improves the imaging efficiency.

In step 101, a group of sub-aperture image groups corresponding to the antenna phase centers are obtained, and the sub-aperture image groups are obtained by imaging on a reference height plane according to the sub-aperture data of each antenna phase center.

In one embodiment, as shown in FIG. 2, a group of sub-aperture image groups corresponding to the antenna phase centers are obtained as follows:

Step 201: Divide the circular apertures of at least two antenna phase centers to obtain sub-aperture data of each antenna phase center;

Step 202: Image the sub-aperture data of each antenna phase center on a reference height plane to obtain a group of sub-aperture image groups corresponding to the antenna phase centers.

FIG. 3 is an interferometric circular SAR geometric model in an embodiment of the present invention. The radar platform contains two cross-directional antenna phase centers: antenna phase center 1 and antenna phase center 2, that is, the line connecting the two antenna phase centers is perpendicular to the direction of the radar platform track, and the line connecting the two antenna phase centers is called the baseline. The length of the baseline is B, and the angle between the baseline and the horizontal plane is β. The radar platform makes a 360° circular motion around the area of interest, θ∈[0,2π) is the azimuth angle, H is the height of the radar platform from the ground, and R is the trajectory radius of the antenna phase center 1. The two independent circular apertures obtained by the phase centers of the two interference antennas are divided into M sub-apertures. Generally, each sub-aperture is 1° and can be divided into 360 sub-apertures. The collected sub-aperture data are imaged separately on the reference height plane, and h ₀ is the reference height, which is generally taken as the height of the ground plane. Images S _1i (x, y), S _2i (x, y) are obtained. Represents the coordinates of the pixel, the subscripts 1 and 2 represent the antenna phase center 1 and the antenna phase center 2 respectively, and represent the sub-aperture serial number, =1,2,...,M.

In step 102, interference processing is performed on the sub-aperture image group to obtain a winding interference phase.

其中，符号*表示共轭。In specific implementation, interference processing is performed on the sub-aperture image pairs corresponding to the phase centers of the two antennas to obtain the interfering phase of the winding.

Wherein, the symbol * represents conjugation.

In step 103, a plurality of phase ambiguity numbers are determined according to the winding interference phase, the height range of the scene, and the relationship between the height difference and the winding interference phase established in advance.

In one embodiment, the relationship between the height difference and the winding interference phase is pre-established according to the following formula:

Among them, Δh _i,k (x, y) is the height difference, c is the speed of light, φ _i,k (x, y) is the winding interference phase, and R _p1 is the phase center of the sub-aperture antenna to the pixel point (x, y, h ₀ ), f _c is the center frequency of the signal transmitted by the antenna, B is the length of the baseline, ψ is the pitch angle of the radar relative to the pixel point, β is the angle between the baseline and the horizontal plane, and k is the phase ambiguity number.

In specific implementation, φ _i,k (x, y) is the absolute phase, that is, φ _i,k (x, y)=φ _i (x, y)+2π·k, and k is the phase ambiguity number. According to the known height range of the scene, determine the possible phase ambiguity number k, a total of K, which are positive integers. The phase ambiguity number can be calculated based on the winding interference phase, the scene height range and the relationship between the pre-established height difference and the winding interference phase. The relationship between the height difference and the winding interference phase is derived as follows:

First, the height difference is calculated, and the height difference between the K possible targets and the reference height is obtained through the slant distance difference. The relationship between the slant distance difference and the winding interference phase is:

where c is the speed of light and f _c represents the center frequency of the signal transmitted by the antenna.

Then, calculate the K possible height differences:

Among them, R _p1 is the distance from the sub-aperture antenna phase center 1 to the pixel point (x, y, h ₀ ), and ψ is the pitch angle of the radar relative to the pixel point.

Furthermore, the relationship between the height difference and the winding interference phase can be obtained:

Among them, Δh _i,k (x, y) is the height difference, c is the speed of light, φ _i,k (x, y) is the winding interference phase, and R _p1 is the phase center of the sub-aperture antenna to the pixel point (x, y, h ₀ ), f _c is the center frequency of the signal transmitted by the antenna, B is the length of the baseline, ψ is the pitch angle of the radar relative to the pixel point, β is the angle between the baseline and the horizontal plane, and k is the phase ambiguity number.

In step 104, according to the plurality of phase ambiguities, the range Doppler equation is used to calculate a plurality of three-dimensional positions under each sub-aperture.

During specific implementation, K three-dimensional positions under the i-th sub-aperture are solved by using the Range Doppler (RD) equation.

子孔径中心为D_i。子孔径投影平面上的像素坐标为(x,y,h₀)_i，设为P_i；K种三维坐标为(x_k,y_k,h_k)_i，设为P_i,′_k，其中h_k＝h₀+Δh_i,k。RD方程如下：Let the velocity vector of the subaperture radar platform be

The sub-aperture center is _Di. The pixel coordinates on the sub-aperture projection plane are (x, y, h ₀ ) _i , set as P _i ; the K three-dimensional coordinates are (x _k , y _k , h _k ) _i , set as P _i, ′ _k , where h _k =h ₀ +Δh _i,k . The RD equation is as follows:

Here, the symbol · represents the inner product.

In step 105, a correlation coefficient algorithm is used to select from a plurality of three-dimensional positions under each sub-aperture.

In one embodiment, as shown in FIG. 4 , a correlation coefficient algorithm is used to select from multiple three-dimensional positions under each sub-aperture, including:

Step 401, projecting a plurality of three-dimensional positions under each sub-aperture onto an imaging plane of a preset angle;

Step 402, according to the projection result and the preset window, use the correlation coefficient algorithm to determine the window data correlation coefficient;

Step 403, according to the maximum value in the correlation coefficient of the window data, select a phase ambiguity number estimated value from a plurality of phase ambiguity numbers;

Step 404: According to the estimated value of the phase ambiguity number, select the real three-dimensional coordinates of the target from the multiple three-dimensional positions under each sub-aperture.

一般m取5。选用3×3或5×5的窗口，计算复图像S_1i(x,y)在P_i位置的窗口数据与复图像S_1i+m(x,y)在

位置的窗口数据的相关系数ρ_i,k(x,y)，取相关系数最大值对应的k为最终估计的模糊数，即

相应的

就是目标最有可能的三维真实坐标，实现了利用方位角度的解模糊。相关系数ρ_i,k如下：In the specific implementation, the RD projection relationship is used to project the i-th angle P _i, ' _k on the imaging plane of the i+m-th angle, as follows:

Generally, m is taken as 5. Choose a 3×3 or 5×5 window, calculate the window data of the complex image S _1i (x,y) at the position Pi and the complex image S _{1i +m} (x,y) in

The correlation coefficient ρ _i,k (x, y) of the window data of the position, take the k corresponding to the maximum value of the correlation coefficient as the final estimated fuzzy number, that is

corresponding

It is the most probable three-dimensional real coordinates of the target, which realizes the deblurring by using the azimuth angle. The correlation coefficient ρ _i,k is as follows:

位置的窗口数据，

和

为窗口数据的平均值。Among them, n is the window size, I _i is the window data of the complex image S _1i (x, y) at the position P _i , I _i+m complex image S _1i+m (x, y) is in

position window data,

and

is the mean value of the window data.

In step 106, according to the selected result, the interferometric circular SAR three-dimensional imaging of the complex structural building is performed.

即得到全方位的三维点云。In specific implementation, after performing the above steps on all M sub-apertures, the obtained three-dimensional point clouds of M angles are merged, and there are

That is, an omnidirectional 3D point cloud is obtained.

The embodiment of the present invention adopts three-dimensional point cloud imaging. First, the three-dimensional point cloud is first established with the interferometric SAR data of a certain angle, which reduces the amount of data storage and calculation, and then the phase ambiguity number is obtained by using the multi-angle data, and there is no need to solve the phase winding. Finally, the A collection of point clouds from various angles forms an omnidirectional 3D point cloud.

The interferometric circular SAR three-dimensional imaging method for complex structural buildings provided by the embodiments of the present invention has the following advantages:

1. Better use of multi-angle information, no need for dual-frequency interference or phase unwrapping;

2. The problem of large amount of calculation and large memory occupation when performing 3D imaging of complex structures with interferometric circular SAR has been improved, so that the 3D imaging efficiency is higher.

Based on the same inventive concept, an embodiment of the present invention also provides an interferometric circular SAR three-dimensional imaging device for a complex structural building, as described in the following embodiments. Since the principle of solving these problems is similar to the interferometric circular SAR 3D imaging method for complex structural buildings, the implementation of the interferometric circular SAR 3D imaging device for complex structural buildings can refer to the implementation of the method, and the repetition will not be repeated.

5 is a structural diagram of an interferometric circular SAR three-dimensional imaging device for a complex structural building in an embodiment of the present invention. As shown in FIG. 5 , the interferometric circular SAR three-dimensional imaging device for the complex structural building includes:

A sub-aperture image group obtaining module 501, configured to obtain a group of sub-aperture image groups corresponding to the antenna phase centers, the sub-aperture image groups are obtained by imaging on a reference height plane according to the sub-aperture data of each antenna phase center;

a sub-aperture image group interference processing module 502, configured to perform interference processing on the sub-aperture image group to obtain a winding interference phase;

A phase ambiguity number determination module 503, configured to determine a plurality of phase ambiguity numbers according to the winding interference phase, the height range of the scene and the relationship between the height difference and the winding interference phase established in advance;

A sub-aperture three-dimensional position calculation module 504, configured to calculate a plurality of three-dimensional positions under each sub-aperture by using the range Doppler equation according to the plurality of phase ambiguities;

A sub-aperture three-dimensional position selection module 505, configured to use a correlation coefficient algorithm to select from a plurality of three-dimensional positions under each sub-aperture;

The interferometric circular SAR three-dimensional imaging module 506 is configured to perform interferometric circular SAR three-dimensional imaging of complex structures according to the selected results.

In one embodiment, the sub-aperture image group obtaining module 501 is further configured to obtain a group of sub-aperture image groups corresponding to the antenna phase centers as follows:

Divide the circular apertures of at least two antenna phase centers to obtain sub-aperture data of each antenna phase center;

The sub-aperture data of each antenna phase center is imaged on a reference height plane to obtain a group of sub-aperture image groups corresponding to the antenna phase centers.

In one embodiment, the sub-aperture three-dimensional position selection module 505 is further configured to:

Projecting multiple three-dimensional positions under each sub-aperture onto the imaging plane at a preset angle;

According to the projection result and the preset window, use the correlation coefficient algorithm to determine the window data correlation coefficient;

According to the maximum value in the correlation coefficient of the window data, the estimated value of the phase ambiguity number is selected from the plurality of phase ambiguity numbers;

According to the estimated value of the phase ambiguity number, the three-dimensional real coordinates of the target are selected from a plurality of three-dimensional positions under each sub-aperture.

Based on the foregoing inventive concept, an embodiment of the present invention further provides a computer device, including a memory, a processor, and a computer program stored in the memory and running on the processor, where the processor implements the above complex when executing the computer program. Interferometric circular SAR 3D imaging method for structural buildings.

Based on the foregoing inventive concept, an embodiment of the present invention further provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the above-mentioned interferometric circular SAR three-dimensional building of the complex structure is realized. imaging method.

An embodiment of the present invention further provides a computer program product, the computer program product includes a computer program, and when the computer program is executed by a processor, realizes the above-mentioned interferometric circular SAR three-dimensional imaging method for a complex structural building.

In the embodiment of the present invention, a group of sub-aperture image groups corresponding to the antenna phase centers are obtained, and the sub-aperture image groups are obtained by imaging on the reference height plane according to the sub-aperture data of each antenna phase center; group to perform interference processing to obtain the winding interference phase; according to the winding interference phase, the height range of the scene and the relationship between the height difference and the winding interference phase established in advance, determine multiple phase ambiguities; according to the multiple phase ambiguities, use The distance Doppler equation calculates multiple three-dimensional positions under each sub-aperture; uses the correlation coefficient algorithm to select from the multiple three-dimensional positions under each sub-aperture; according to the selected results, the interferometric circular SAR three-dimensional imaging. The embodiment of the present invention performs imaging on the reference height plane according to the sub-aperture data of each antenna phase center to obtain a sub-aperture image group, and effectively uses the multi-angle information of each sub-aperture to perform interference processing on the sub-aperture image group to obtain the winding interference phase, No dual-frequency interference or phase unwrapping is required. According to the winding interference phase, the height range of the scene and the relationship between the pre-established height difference and the winding interference phase, multiple phase ambiguities are determined, and the distance Doppler equation is used to calculate multiple three-dimensional positions under each sub-aperture, and then use the correlation coefficient algorithm By selecting from multiple three-dimensional positions under each sub-aperture, the interferometric circular SAR three-dimensional imaging of complex structural buildings can be performed, which effectively reduces the amount of data storage and calculation, and improves the imaging efficiency.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flow of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. An interference circumference SAR three-dimensional imaging method of a complex structure building is characterized by comprising the following steps:

acquiring a group of sub-aperture image groups corresponding to the antenna phase centers, wherein the sub-aperture image groups are obtained by imaging in a reference height plane according to sub-aperture data of each antenna phase center;

performing interference processing on the sub-aperture image group to obtain a winding interference phase;

determining a plurality of phase ambiguity numbers according to the winding interference phase, the scene height range and the pre-established relationship between the height difference and the winding interference phase;

calculating a plurality of three-dimensional positions under each sub-aperture by using a range-Doppler equation according to the plurality of phase ambiguity numbers;

selecting from a plurality of three-dimensional positions under each sub-aperture by using a correlation coefficient algorithm;

and according to the selected result, performing interference circumference SAR three-dimensional imaging of the complex structure building.

2. The interference circular SAR three-dimensional imaging method of the complex structure building as claimed in claim 1, characterized in that a set of sub-aperture image sets corresponding to the antenna phase center is obtained as follows:

dividing the circumferential apertures of at least two antenna phase centers to obtain sub-aperture data of each antenna phase center;

and imaging the sub-aperture data of each antenna phase center on a reference height plane to obtain a group of sub-aperture image groups corresponding to the antenna phase centers.

3. The three-dimensional imaging method of the interference circumference SAR of the complex structure building as claimed in claim 1, characterized in that the relationship between the height difference and the winding interference phase is pre-established according to the following formula:

wherein,. DELTA.h_i,k(x, y) is the height difference, c is the speed of light, phi_i,k(x, y) is the phase of the winding interference, R_p1For sub-aperture antenna phase center to pixel (x, y, h)₀) Distance of (f)_cThe central frequency of the antenna transmitting signal, B is the length of a base line, psi is the pitch angle of the radar relative to the pixel point, beta is the included angle between the base line and the horizontal plane, and k is the phase ambiguity number.

4. The interferometric circular SAR three-dimensional imaging method for the complex structure building as claimed in claim 1, wherein the selecting from the plurality of three-dimensional positions under each sub-aperture by using the correlation coefficient algorithm comprises:

projecting a plurality of three-dimensional positions under each sub-aperture onto an imaging plane with a preset angle;

determining a window data correlation coefficient by using a correlation coefficient algorithm according to a projection result and a preset window;

selecting a phase ambiguity number estimation value from a plurality of phase ambiguity numbers according to the maximum value in the window data correlation coefficient;

and selecting a target three-dimensional real coordinate from a plurality of three-dimensional positions under each sub-aperture according to the phase ambiguity number estimated value.

5. An interference circumference SAR three-dimensional imaging device of a complex structure building is characterized by comprising:

the system comprises a sub-aperture image group obtaining module, a sub-aperture image group obtaining module and a sub-aperture image group acquiring module, wherein the sub-aperture image group obtaining module is used for obtaining a group of sub-aperture image groups corresponding to antenna phase centers, and the sub-aperture image groups are obtained by imaging on a reference height plane according to sub-aperture data of each antenna phase center;

the sub-aperture image group interference processing module is used for carrying out interference processing on the sub-aperture image group to obtain a winding interference phase;

the phase ambiguity number determining module is used for determining a plurality of phase ambiguity numbers according to the winding interference phase, the scene height range and the pre-established relationship between the height difference and the winding interference phase;

the sub-aperture three-dimensional position calculation module is used for calculating a plurality of three-dimensional positions under each sub-aperture by using a range-Doppler equation according to the plurality of phase ambiguity numbers;

the sub-aperture three-dimensional position selection module is used for selecting from a plurality of three-dimensional positions under each sub-aperture by utilizing a correlation coefficient algorithm;

and the interference circumference SAR three-dimensional imaging module is used for performing interference circumference SAR three-dimensional imaging of the complex structure building according to the selected result.

6. The interference circular SAR three-dimensional imaging device of the complex structure building as claimed in claim 5, wherein the sub-aperture image group obtaining module is further configured to obtain a group of sub-aperture image groups corresponding to the antenna phase center as follows:

dividing the circumferential apertures of at least two antenna phase centers to obtain sub-aperture data of each antenna phase center;

and imaging the sub-aperture data of each antenna phase center on a reference height plane to obtain a group of sub-aperture image groups corresponding to the antenna phase centers.

7. The interferometric circular SAR three-dimensional imaging device for the complex structure building as claimed in claim 5, wherein the sub-aperture three-dimensional position selection module is further configured to:

projecting a plurality of three-dimensional positions under each sub-aperture onto an imaging plane at a preset angle;

determining a window data correlation coefficient by using a correlation coefficient algorithm according to a projection result and a preset window;

selecting a phase ambiguity number estimation value from a plurality of phase ambiguity numbers according to the maximum value in the window data correlation coefficient;

and selecting a target three-dimensional real coordinate from a plurality of three-dimensional positions under each sub-aperture according to the phase ambiguity number estimated value.

8. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of any one of claims 1 to 4 when executing the computer program.

9. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program which, when executed by a processor, implements the method of any of claims 1 to 4.

10. A computer program product, characterized in that the computer program product comprises a computer program which, when being executed by a processor, carries out the method of any one of claims 1 to 4.

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