KR101713173B1 - Method for improving accuracy of target detection - Google Patents

Abstract

The present invention relates to a method for improving the accuracy of target detection. A method for improving the accuracy of target detection in accordance with the present invention includes receiving multi-polarized SAR data for a predetermined region comprising a target from a synthetic aperture radar (SAR) and generating polarimetric entropy and correlation from the multi- obtaining a polarimetric coherence and reducing noise contained in the region based on the difference and sum of the polarization entropy and the correlation to improve the accuracy of target detection. This can improve the accuracy of target detection using multi-polarized SAR data.

Description

[0001] The present invention relates to a method for improving target detection,

The present invention relates to a method for improving the accuracy of target detection, and more particularly to a method for improving the accuracy of target detection using multi-polarized SAR data.

Synthetic Aperture Radar (SAR) is a radar that observes the ground and the ocean in the air. The radar wave is radiated from the air in the air sequentially for the surface and the ocean. To create a terrain topography. Because it uses radar, daytime and nighttime, and bad weather are not used, it is widely used for ground and ocean observation. SAR data may also be used to detect marine vessels. However, in the case of detecting vessels using SAR data, it is possible to detect a number of small islands and intertidal zone areas in the ocean, such as land masking, buoys of various sizes, Are difficult to distinguish from the ship on the SAR data, making it difficult to detect the ship.

It is therefore an object of the present invention to provide a method for improving the accuracy of target detection using multi-polarized SAR data to improve the accuracy of target detection.

The object is achieved, according to the present invention, by a method for improving the accuracy of target detection, comprising the steps of: receiving multi-polarized SAR data for a region containing a target from a synthetic aperture radar (SAR) obtaining a polarimetric entropy and a polarimetric coherence and using the polarization entropy H and the correlation y to reduce the noise included in the region to improve the accuracy of target detection And a method for improving the accuracy of target detection.

Wherein the polarized SAR data comprises HH polarization, VV polarization, HV polarization and VH polarization data, wherein the polarization entropy is data obtained using the HH polarization and the HV polarization data or the VV polarization and the VH polarization data , And the correlation is a correlation between two pieces of the polarized data of the HH polarized wave, the VV polarized wave, the HV polarized wave and the VH polarized wave data.

The target detection accuracy enhancement step reduces the noise included in the region by dividing the sum of the polarization entropy and the correlation degree by the difference between the polarization entropy and the correlation.

The target detection accuracy enhancement step reduces the noise included in the region by dividing the difference between the polarization entropy and the correlation by the sum of the polarization entropy and the correlation.

The target detection accuracy enhancement step divides the polarization entropy ( H ) by the degree of correlation ( ? ) To reduce the noise included in the region.

The target detection accuracy enhancement step reduces the noise included in the region by summing the polarization entropy ( H ) and the value obtained by subtracting the correlation degree ( ? ) From 1.

On the other hand, the above object can be achieved by a computer-readable recording medium on which a program for executing the method for improving the accuracy of the target detection described above is recorded.

As described above, according to the present invention, there is provided a method for improving the accuracy of target detection using multi-polarized SAR data to improve the accuracy of target detection.

1 is a flow chart of a method for improving the accuracy of target detection according to an embodiment of the present invention,
2A is an example of correlated image data according to an embodiment of the present invention,
FIG. 2B is an example of the polarization entropy image data according to an embodiment of the present invention,
FIGS. 3 and 4 are examples of data showing the result of performing the method of FIG.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

1 is a flowchart of a method for improving the accuracy of target detection according to an embodiment of the present invention. Referring to FIG. 1, a method for improving the accuracy of target detection includes receiving (S110) multi-polarized SAR data for a predetermined region including a target from a synthetic aperture radar (SAR), and generating polarized entropy (S120) of acquiring polarimetric entropy and polarimetric coherence, and improving the accuracy of target detection by reducing the noise included in the region using the polarization entropy and the degree of correlation do.

Step S110 is a step of receiving multi-polarized SAR data for a predetermined region including a target from the synthetic aperture reader (SAR).

The Synthetic Aperture Radar (SAR) is a device that reconstructs a two-dimensional image by measuring the reflected wave after it has been shot by an antenna. It is mounted on a reconnaissance satellite / aircraft and is used for surveying, observation, reconnaissance, A high-resolution image of the area can be generated. Various data can be obtained from the synthetic aperture radar according to frequency and polarization.

The polarized SAR data includes at least one of HH polarization (vertical polarization transmission and vertical polarization reception), VV polarization (horizontal polarization transmission and horizontal polarization reception), HV polarization (vertical polarization transmission and horizontal polarization reception) and VH polarization Vertical polarization reception) data, and preferably their polarization data is image data for a predetermined region including the target. The HH and VV polarized data are high resolution data generated by the image mode of the SAR, which includes HH polarization and VV polarization for any of the seven available swaths located for an incident angle width range of 15 to 45 degrees. Image data. The HV polarized wave and the VH polarized wave are generated using the HH polarized wave and the VV polarized wave data generated by the image mode by the alternating polarization mode of the SAR.

The predetermined area including the target refers to a marine area including an object such as a ship, and includes various ranges of areas such as tens to hundreds of kilometers.

Step S120 is a step of obtaining polarimetric entropy and polarimetric coherence from the multi-polarized SAR data.

A polarimetric entropy may be obtained from the HH polarized wave and the HV polarized wave data or may be obtained from the VV polarized wave and the VH polarized wave data. The polarization entropy exhibits a high tendency in the case of a target causing arbitrary scattering, for example, a ship, which is constituted by various scattering processes in the predetermined region, and the surface scattering in the predetermined region, for example, And a low tendency in the case of the target to be generated.

The polarimetric coherence means a correlation between two polarized data of the HH polarized wave, the VV polarized wave, the HV polarized wave and the VH polarized wave data. The quantitative value indicating the correspondence between the two data is displayed in the form of image data . The closer the correlation is to 1, the higher the correspondence between the two data for one point, and the closer the correlation is to 0, the lower the correspondence between the two data for any one point. Therefore, in the case of a target such as a ship, the correspondence is low due to volume or multiple scattering between two polarized data of the HH polarized wave, VV polarized wave, HV polarized wave and VH polarized wave data, It can be seen that there is a high correspondence between the two polarized data of the HH polarized wave, the VV polarized wave, the HV polarized wave and the VH polarized wave data due to a single scattering or the like. As another example, the correlation diagram according to the present invention may be expressed by the following equation.

[Mathematical Expression]

γ = 1 - γ '

Here ,? Is a correlation and ? ' Is a correlation coefficient between two polarized data of the HH polarized wave, the VV polarized wave, the HV polarized wave and the VH polarized data. The correlation coefficient between the two polarized data of the HH polarized wave, the VV polarized wave, the HV polarized wave and the VH polarized wave data is lower in the case of the ship causing multiple scattering as compared with the sea surface where the surface scattering occurs.

FIG. 2A is correlation image data according to an embodiment of the present invention, and FIG. 2B is polarization entropy image data according to an embodiment of the present invention.

As shown in FIG. 2A, the correlation between the land L and predetermined target objects is low due to volume or multiple scattering, and the degree of correlation is considerably high in the case of the sea. At this time, it is confirmed that there are a plurality of targets between the two land (L), but it can be confirmed that the accuracy of the target position in the elliptical region is low due to the noise.

As shown in FIG. 2B, the terrestrial L and predetermined target objects exhibit a high polarization entropy due to multiple scattering or the like, and the polarization entropy is low due to a single scattering in the sea. At this time, it is confirmed that there are a plurality of targets between the two land (L), but it can be confirmed that the accuracy of the target position in the elliptical region is low due to the noise.

Meanwhile, in step S130, the noise included in the region is reduced using the polarization entropy and the correlation to improve the accuracy of target detection. The target, which is to be detected in the region, by properly using the difference, sum, and division of the correlation degree ( gamma ) with the polarization entropy ( H ) with respect to the region including the target obtained in the step S120 Other noise can be effectively removed.

In embodiments, it may be a polarization-entropy (H) and the correlation (γ) by dividing the sum of the polarization drive entropy (H) and the correlation (γ) for reducing the noise contained in the area. That is, the noise included in the region can be reduced by using the equation ( H + ? ) / ( H - ? ) To improve the accuracy of target detection.

In another embodiment, divided by the sum of the a difference between the correlation (γ) with the polarization entropy (H) and polarization entropy (H) the correlation (γ) it is possible to reduce the noise contained in the area. That is, by using the ( H - ? ) / ( H + ? ) Equation, the noise contained in the region can be reduced to improve the accuracy of target detection.

Figure 3 is, the of the two embodiments described above polarization entropy (H) and the correlation wherein the sum of (γ) polarization entropy (H) and the correlation divided drive the (γ) of the noise included in the area ( H + ? ) / ( H - ?

Compared with FIG. 2A and FIG. 2B, the two land L and a plurality of targets located therebetween are clearly visible because the noise in the sea region other than the target is mostly removed. Thus, according to the present invention, the accuracy of target detection can be improved through the noise removal according to the new method in the region including the target, thereby helping to correct the accuracy of the positioning of the target such as the ship.

On the other hand, as another embodiment, as shown in the H / γ, as the correlation divided by (γ) the polarization entropy (H), H +, such as (1- γ), in the polarization entropy (H) with 1 It is possible to reduce the noise contained in the region by the sum of the values obtained by subtracting the correlation degree [ gamma ], thereby improving the accuracy of target detection.

FIG. 4 shows the result of performing the target detection accuracy improvement method according to another embodiment of the present invention such as H / gamma and H + (1- ? ). As shown in this figure, the noise in the sea region is removed even in the case of H / ? And H + (1- ? ), As compared with FIGS. 2A and 2B. Are clearly visible.

Thus, according to the present invention, the accuracy of target detection can be improved through the noise removal according to the new method in the region including the target, thereby improving the accuracy of the positioning of the target such as the ship Can be confirmed.

Meanwhile, the present invention can provide a computer-readable recording medium on which a program for performing the method for improving the accuracy of target detection described above with reference to FIG. 1 to FIG. 3 is recorded. . The program is stored in a computer-readable medium and is read by a computer to perform the functions. The medium may be any of those specifically designed or configured for the present invention or may be known and used by those skilled in the computer software arts. A magnetic recording medium such as a CD, a DVD, a magnetic-optical recording medium that can also serve as both a magnetic recording medium and a magnetic recording medium, a ROM, a RAM, and a flash memory. Memory, or the like, or a hardware device specifically configured to store and execute program instructions by a combination thereof. In addition, the program may be stored in a server system capable of transmitting information through a communication network such as an intranet or the Internet, and may be transmitted to a computer, as well as being read by a computer by the medium. A computer can access the server system without sending it to a computer and provide a platform on which the program can be executed on the server system.

Although several embodiments of the present invention have been shown and described, those skilled in the art will readily appreciate that many modifications may be made without departing from the spirit or scope of the invention . The scope of the invention will be determined by the appended claims and their equivalents.

γ: Correlation diagram H: Polarization entropy

Claims (7)

delete delete In a method for improving the accuracy of target detection,
Receiving multipolar SAR data for a predetermined region including a target from a synthetic aperture radar (SAR); and
Obtaining polarimetric entropy ( H ) and polarimetric coherence ( γ ) from the multi-polarized SAR data;
And reducing the noise included in the region using the polarization entropy ( H ) and the correlation ( ? ) To improve the accuracy of target detection,
Wherein the multi-polarized SAR data comprises HH polarization, VV polarization, HV polarization and VH polarization data,
The polarization entropy (H) is data obtained using the HH polarized wave and the HV polarized wave data or the VV polarized wave and the VH polarized wave data,
The correlation ([gamma]) is a correlation ([gamma]) between two polarized data of the HH polarized wave, the VV polarized wave, the HV polarized wave and the VH polarized wave data,
The target detection accuracy enhancement step includes:
How to improve the accuracy of target detection to which the polarization entropy (H) and the correlation (γ) must divide the drive of the polarization entropy (H) and the correlation (γ) for reducing the noise contained in the area. In a method for improving the accuracy of target detection,
Receiving multipolar SAR data for a predetermined region including a target from a synthetic aperture radar (SAR); and
Obtaining polarimetric entropy ( H ) and polarimetric coherence ( γ ) from the multi-polarized SAR data;
And reducing the noise included in the region using the polarization entropy ( H ) and the correlation ( ? ) To improve the accuracy of target detection,
Wherein the multi-polarized SAR data comprises HH polarization, VV polarization, HV polarization and VH polarization data,
The polarization entropy (H) is data obtained using the HH polarized wave and the HV polarized wave data or the VV polarized wave and the VH polarized wave data,
The correlation ([gamma]) is a correlation ([gamma]) between two polarized data of the HH polarized wave, the VV polarized wave, the HV polarized wave and the VH polarized wave data,
The target detection accuracy enhancement step includes:
The above polarization entropy (H) and the correlation (γ) polarization entropy (H) wherein the difference between the correlation by dividing the sum of (γ) how to improve the accuracy of the target detection would reduce the noise contained in the area . In a method for improving the accuracy of target detection,
Receiving multipolar SAR data for a predetermined region including a target from a synthetic aperture radar (SAR); and
Obtaining polarimetric entropy ( H ) and polarimetric coherence ( γ ) from the multi-polarized SAR data;
And reducing the noise included in the region using the polarization entropy ( H ) and the correlation ( ? ) To improve the accuracy of target detection,
Wherein the multi-polarized SAR data comprises HH polarization, VV polarization, HV polarization and VH polarization data,
The polarization entropy (H) is data obtained using the HH polarized wave and the HV polarized wave data or the VV polarized wave and the VH polarized wave data,
The correlation ([gamma]) is a correlation ([gamma]) between two polarized data of the HH polarized wave, the VV polarized wave, the HV polarized wave and the VH polarized wave data,
The target detection accuracy enhancement step includes:
And dividing the polarization entropy ( H ) by the correlation ([ gamma] ) to reduce the noise contained in the region. In a method for improving the accuracy of target detection,
Receiving multipolar SAR data for a predetermined region including a target from a synthetic aperture radar (SAR); and
Obtaining polarimetric entropy ( H ) and polarimetric coherence ( γ ) from the multi-polarized SAR data;
And reducing the noise included in the region using the polarization entropy ( H ) and the correlation ( ? ) To improve the accuracy of target detection,
Wherein the multi-polarized SAR data comprises HH polarization, VV polarization, HV polarization and VH polarization data,
The polarization entropy (H) is data obtained using the HH polarized wave and the HV polarized wave data or the VV polarized wave and the VH polarized wave data,
The correlation ([gamma]) is a correlation ([gamma]) between two polarized data of the HH polarized wave, the VV polarized wave, the HV polarized wave and the VH polarized wave data,
The target detection accuracy enhancement step includes:
And decreasing the noise included in the region by the sum of the polarization entropy ( H ) minus the correlation ( gamma ) from 1. The method of claim 1, A computer-readable recording medium having recorded thereon a program for executing a method for improving the accuracy of the target detection according to any one of claims 3 to 6.

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