KR-20260063568-A - APPARATUS OF DETERMINING VERTICAL ANGLE OF TARGET SIGNAL USING COMBINATION OF HORIZONTAL ARRAY SONAR AND METHOD THEREOF

KR20260063568AKR 20260063568 AKR20260063568 AKR 20260063568AKR-20260063568-A

Abstract

An apparatus for determining the direction of a target signal according to one embodiment of the present disclosure may be provided, comprising: at least one first horizontal array sonar configured to acquire a first target signal for a target; at least two second horizontal array sonars stacked perpendicularly to each other and configured to acquire a second target signal for a target; and a processor configured to determine azimuth information and cone angle information regarding the direction of a target signal based on the first target signal and the second target signal, and to determine elevation information regarding the direction of a target signal based on the azimuth information and cone angle information. As another embodiment, a method for determining the direction of a target signal and a recording medium storing a computer program for performing the method may be provided.

Inventors

오래근
이단비
권택익

Assignees

국방과학연구소

Dates

Publication Date: 20260507
Application Date: 20241030

Claims (10)

In a device for determining the direction of a target signal, At least one first horizontal array sonar configured to acquire a first target signal for the above target; At least two second horizontal array sonar units configured to be stacked perpendicularly to each other to acquire a second target signal for the said target; and A device comprising a processor configured to determine azimuth information and cone angle information regarding the direction of the target signal based on the first target signal and the second target signal, and to determine elevation information regarding the direction of the target signal based on the azimuth information and the cone angle information.
In Article 1, A device configured such that the processor determines the up and down direction of the target signal based on the difference in arrival time or phase between the target signals acquired through each of the at least two second horizontal array sonar.
In Article 2, A device comprising at least two second horizontal array sonars, each of which is a type of horizontal array sonar different from the at least one first horizontal array sonar among a cylindrical array sonar and a linear array sonar.
In Paragraph 3, The above at least one first horizontal array sonar includes a linear array sonar, and The above device comprises at least two second horizontal array sonars, each comprising a cylindrical array sonar.
In Paragraph 3, The above at least one first horizontal array sonar includes a cylindrical array sonar, and The above device comprises at least two second horizontal array sonars, each comprising a linear array sonar.
In claim 3, the processor, The azimuth information is determined based on the first target signal and the second target signal acquired through a cylindrical array sonar, and Based on the determined azimuth information and the second target signal, the cone angle information is determined, and A device configured to determine elevation information based on the above azimuth information and the above cone angle information.
In Article 1, A device comprising at least one first horizontal array sonar and at least two second horizontal array sonars, wherein the two second horizontal array sonars comprise linear array sonar.
In Article 7, The above at least one first horizontal array sonar is arranged in a different direction from the above at least two second horizontal array sonars, and The above processor is, Determining first cone angle information based on the above first target signal, and Determining second cone angle information based on the above second target signal, and A device configured to determine the azimuth information for the direction of the target signal based on the cone angle information that is relatively close to the broadside of each of the at least one first horizontal array sonar and the at least two second horizontal array sonar among the first cone angle information and the second cone angle information, and to determine other cone angle information as the cone angle information for the direction of the target signal.
In a method for determining the direction of a target signal, A step of acquiring a first target signal for the target through at least one first horizontal array sonar; A step of acquiring a second target signal for the target through at least two second horizontal array sonar that are stacked perpendicularly to each other; A step of determining azimuth information and cone angle information regarding the direction of the target signal based on the first target signal and the second target signal; and A method comprising the step of determining elevation information for the direction of the target signal based on the azimuth information and the cone angle information.
In a non-transient computer-readable recording medium storing a computer program for performing a method for determining the direction of a target signal, the method comprises: A step of acquiring a first target signal for the target through at least one first horizontal array sonar; A step of acquiring a second target signal for the target through at least two second horizontal array sonar that are stacked perpendicularly to each other; A step of determining azimuth information and cone angle information regarding the direction of the target signal based on the first target signal and the second target signal; and A non-transient computer-readable recording medium comprising the step of determining elevation information for the direction of the target signal based on the azimuth information and the cone angle information.

Description

Apparatus of determining vertical angle of target signal using combination of horizontal array sonar and method thereof The present disclosure relates to an apparatus and method for determining the elevation angle of a target signal using a combination of horizontal array sonar. Specifically, the present disclosure is an invention regarding an apparatus and method for determining the elevation angle information of a target by combining horizontal array sonar used on a platform where vertical space constraints exist. In environments where the use of radio waves is restricted, target detection is performed using a SONAR (Sound Navigation and Ranging System) that receives sound waves, and the SONAR is installed and operated on underwater and surface platforms. In water, sound waves are transmitted in three dimensions including horizontal and vertical directions, and generally, a horizontal array sonar is used to measure the horizontal azimuth and a vertical array sonar is used to determine the vertical elevation. Array sonar performs beamforming to measure azimuth and elevation, and Equation 1, which simply simulates the 3dB beamwidth (q 3dB )—one of the beamforming performance evaluation metrics—for a linear array sonar, is as follows [Waite, Ashley D. Sonar for Practising Engineers, 2002.]. Here, q0 represents the beam steering angle, f represents the frequency, and L represents the array length. Looking at Equation 1, it can be seen that as the array length increases, the beam width in the beamforming result decreases, which improves the resolution of the array sonar and thus enhances measurement performance. Additionally, for long-range underwater targets, it is advantageous to detect sound waves in the mid-to-low frequency band, which have low transmission loss. According to Equation 1, as the frequency band decreases, the array length must be increased to maintain a 3dB beam width. As such, a long vertical array is required to improve elevation measurement performance using array sonar for the reasons mentioned above; however, mobile underwater and surface platforms used for various purposes face limitations in vertical space compared to horizontal space. Therefore, elevation information of target signals obtainable from mobile underwater and surface platforms has lower resolution compared to azimuth information measured from long horizontal arrays, and there is a disadvantage in detecting signals with low frequency bands. Generally, Cylindrical Array Sonar (CAS), Flank Array Sonar (FAS), and Towed Array Sonar (TAS) are used for target detection, and azimuth measurement is primarily performed using horizontal array sonar. The result generated by tracking measurements from sonar over time is called a track, and the process of comparing tracks generated from multiple sonar to determine whether they are the same target is called track association. Research on track association is continuously being conducted. Using this association method, it is possible to determine whether signals measured by each sonar are the same target (Patent Application No. 10-2024-0020649). Recently, research has been conducted to estimate additional information, such as target depth, by utilizing elevation data from target signals, and the need for sonar capable of measuring the elevation of target signals is increasing. While sonar capable of measuring elevation exists on mobile underwater and surface platforms, most of them have operating frequency ranges unsuitable for long-range target detection or suffer from low elevation resolution. Furthermore, although elevation information of target signals is acquired by vertically extending cylindrical array sonar, performance remains limited even when vertically extended due to the vertical spatial constraints on mobile underwater and surface platforms, as previously explained. FIG. 1 is a block diagram of a device for determining the azimuth and elevation angles of a target signal according to one embodiment. FIG. 2 is a flowchart of a method for determining the azimuth and elevation angles of a target signal according to one embodiment. Figures 3a and 3b illustrate the array configuration of a horizontal array sonar for acquiring target signals. FIGS. 4a and 4b illustrate the results of performing beam forming on a target at an exemplary position in a cylindrical array sonar. FIGS. 5A and 5B illustrate the results of performing beamforming on a target at an exemplary position in a linear array sonar. FIG. 6 illustrates a combination of horizontal array sonar included in a device according to one embodiment. FIG. 7 illustrates azimuth information and cone angle information measured by performing beamforming in the cylindrical array sonar and the linear array sonar of the device of the present disclosure when the actual elevation angle is changed for a target signal according to one embodiment. FIG. 8 is a diagram illustrating the technical effect of a method for determining elevation