KR20130131104A - Position estimating method and system on reducing estimated positioning error for bi-static radar system based on cellular network - Google Patents

Abstract

The present invention relates to a method for reducing a location estimation error by selectively signal-processing a cellular network-based multi-static radar system and a system thereof. In a location estimation method of a bi-static radar system, a location estimation method includes: a step for detecting a target for estimating a location; a step for judging a location of a target with time of arrival (TOA) based least square method; a step for reducing an estimation error of a location of a target judged using pseudo mono-static information; a step for finally determining a location of a target by comparing the pseudo mono-static information and information of a bi-static system. [Reference numerals] (310) Detecting the target of which location is estimated;(320) Deciding the location of the target with the TOA-based least square method;(330) Reducing an estimation error using the pseudo mono-static information;(340) Finally deciding the location of the target by comparing the pseudo mono-static information with the information of a bi-static system;(AA) Start;(BB) End

Description

POSITION ESTIMATING METHOD AND SYSTEM ON REDUCING ESTIMATED POSITIONING ERROR FOR BI-STATIC RADAR SYSTEM BASED ON CELLULAR NETWORK}

The present invention relates to a method and a system for reducing the position estimation error by selectively signal processing in a mobile phone network-based multiple separation radar system.

Cellular network-based radar system is a radar system that has fast detection and wide detection area by using base station signal of wireless communication network. Such a system can be considered a bi-static radar system with separate transmitter and receiver.

In such a radar system, after detecting a target, the position of the target is determined. To this end, the distance between the target and the receiving antenna can be estimated using methods of Time of Arrival (TOA), Time Difference of Arrival (TDOA), and Angle of Arrival (AOA), and from these distances, an analytical method is obtained. And the least square method can be used to determine the location information of the target.

In the dual split radar system based on the mobile phone network, the accuracy of the target position estimation is reduced and the accuracy is improved.

The present invention aims to more accurately estimate the position of a target without significant change in the conventional system by adding a new algorithm in the dual split radar system based on the mobile phone network.

The TOA-based least-squares method can be applied to determine the fast changing target position in the dual separation radar system based on the mobile phone network. At this time, the distance information obtained through the least square method inevitably occurs due to environmental factors such as reflection, scattering, diffraction characteristics and barometric pressure of the radio wave, and transmission / reception end distance error and incident angle error of the radio wave reflected by the receiver. Since this error makes it difficult to properly respond in the presence of enemy, it is possible to selectively apply the position estimation result through the pseudo mono-static information to reduce the position estimation error of the target and increase the accuracy.

The technical challenge is to implement an algorithm that can utilize the optimal pseudo mono-static information at the same time as the method of setting the selection criteria among the pseudo mono-static information and the information obtained from the least-square method.

CLAIMS 1. A position estimation method of a dual split radar system, comprising: detecting a target for estimating a position; Determining a position of the target by a least square method based on a time of argument (TOA); Reducing the estimation error of the position of the target determined using the pseudo mono-static information; And finally determining the position of the target by comparing pseudo mono-static information with information of the dual separation system.

In one aspect, the position estimation method is implemented in a dual separation radar system based on a mobile phone network, the dual separation radar system includes a transmitter and at least three receivers.

In another aspect, the transmitter and receiver include a device for recognizing its position, and the receiver includes a device for measuring an angle of incidence of a signal reflected and transmitted from a target.

In another aspect, the step of determining the position of the target by a time-of-arrival (TOA) -based least squares method, obtaining the equation of the circle as the number of receivers of the dual separation radar system, the intersection or intersection of the equation of the circle One point in the area is estimated by the location of the target.

In another aspect, the position of the target is estimated by transforming the original equation into a matrix equation and calculating the matrix equation.

In another aspect, the step of reducing the estimation error of the position of the target determined using the pseudo mono-static information is a straight line passing both the coordinates of the target and the transmitter coordinates obtained by the least square method, and the pseudo mono-static information. It is to find the intersection of the circle with the radius between the transmitter and the target.

In another aspect, the intersection of the straight line and the circle obtained in the step of reducing the estimation error of the position of the target determined using the pseudo mono-static information is two, and the coordinate of the target obtained by the least square method is one of the two intersection points. Mapping to

In another aspect, the intersection point of the two intersection points is to select an intersection point close to the position of the determined target calculated by the least square method.

In another aspect, in the step of finally determining the position of the target by comparing the pseudo mono-static information with the information of the dual separation system, the coordinates closer to the transmitter are selected among the mapped coordinates and the coordinates before they are mapped. .

A position estimating system of a dual split radar system, comprising: a target detector for detecting a target for estimating a position; A position estimator for determining a position of the target by a least square method based on a time of argument (TOA); An error reduction unit for reducing an estimation error of the position of the target determined using the pseudo mono-static information; And a position determination unit for comparing the pseudo mono-static information and the information of the dual separation system to finally determine the position of the target.

In one side, the position estimator obtains a circle equation according to the number of receivers of the dual separation radar system, and estimates the point of intersection of the circle equation, or a point in the intersection region, as the position of the target.

In another aspect, the position of the target is estimated by transforming the original equation into a matrix equation and calculating the matrix equation.

According to the present invention, the position estimation error can be reduced by an additional software algorithm without major change in hardware.

In addition, it is possible to construct a system that easily applies the method proposed by the present invention to any location where a position estimation using a TOA is used.

1 illustrates a dual split radar system model in one embodiment of the invention.
2 is a graph illustrating an error that may appear when estimating the position of a target using a least square method according to an embodiment of the present invention.
3 is a flowchart illustrating each step of a position estimation method to be proposed in an embodiment of the present invention.
4 is a diagram illustrating an example in which pseudo mono-static information may be selectively utilized according to an embodiment of the present invention.
FIG. 5 illustrates an algorithm of a step of finally determining a position of a target by comparing pseudo mono-static information and information of a dual separation system according to an embodiment of the present invention.
6 is a block diagram showing each configuration of a position estimation system according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention aims to achieve a more accurate position estimation by reducing the position estimation error of the target and improving the accuracy in a bi-static radar system based on a mobile phone network. In a dual separation system, after the transmitter reaches the target, scattering of the radio waves occurs and the radio waves reach the receiver. At the same time, radio waves are sent back to the transmitter, which, when received and obtained, can be considered as a pseudo mono-static system, which, in the circumstances mentioned, selects the pseudo mono-static information. Can be used to improve the accuracy of the target position estimation.

In an embodiment of the invention, FIG. 1 illustrates a dual split radar system model. In the dual separation system environment of the present invention, the transmitter 101 and the receiver 102 are separated, and after detecting the target 103, the position of the target 103 is determined. The dual separation radar system for implementing the present invention may include one transmitter 101 and three or more receivers 102.

In the following equation, the distance between the transmitter 101 and the receiver 102 is represented by L, the distance between the transmitter 101 and the target 103 is represented by R _T , and the distance between the receiver 102 and the target 103 is represented by R _R. The angle between R _T and R _R , that is, the angle at which the signal is reflected from the target, is indicated by β.

을 측정하는 장치가 함께 존재할 수 있다. The transmitter 101 and the receiver 102 of FIG. 1 include a device that recognizes its position. In particular, the receiver has an incident angle of a signal reflected and transmitted from a target, of FIG.

Can be present together.

In FIG. 1, a receiver looking angle, which is an incident angle of a reflected radio wave, and a distance between a transmitter and a receiver may be measured by a measuring device. It is also possible to measure R _T + R _R using the TOA technique. However, these values may have an error, which may cause an error as shown in FIG. 2 when estimating the position of the target using the least square method. The error of FIG. 2 is an error by measurement, and shows an error when R _T + R _R = 100 km and L = 10 km. Examples of the error to be measured may include a measurement error of the entire moving path of the signal, a measurement error of the distance between the transmitter and the receiver, and a measurement angle of the looking angle of the receiver.

3 is a flowchart illustrating a position estimation method proposed by the present invention. Detecting (310) a target to estimate a location; Determining a location of the target using a least square method based on a time of argument (320); Reducing the estimation error of the position of the target determined using the pseudo mono-static information (330); And finally determining (340) the position of the target by comparing the pseudo mono-static information with the information of the dual separation system.

을 함께 얻을 수 있다.First, by step 310, it is assumed that a target for estimating a position has been detected in a cell phone based dual separation radar system. At this time, the position of each transmitter and receiver in the system and the distance L between the transmitter and the receiver, and

You can get together.

Here, the least square method position estimation algorithm will be briefly described as an example. In the step 320, the position of the target is determined using a TOA (Time of Arrival) based least square method, and the circle equation is obtained according to the number of receivers of the dual separation radar system, and the intersection or intersection of the obtained circle equation is obtained. One point in the area can be estimated as the location of the target.

In order to estimate the position of the target on the plane, one base station, a transmitter and three or more receivers are required. In this case, if the center coordinates of the receiver are referred to as (x _i , y _i , z _i ) and the distance from the target to the receiver is R _i , this may be expressed by a circle equation as in Equation (1).

로부터 수학식 2와 같이 얻을 수 있다.Here, i means the number of each receiver, R _i is R _T + R _R and L measured in step 310, and

From Equation 2 can be obtained.

From a given n receivers in the system, n circle equations can be obtained, and the point of intersection of the equations of this circle or a point in the area where the circles overlap can be the estimated coordinate. To find this, the equation of n circles can be modified to obtain a matrix equation as shown in Equation 3.

는 표적의 위치로 추정되는 추정좌표를 의미한다. 또한, 수학식 4의 k_i는 기준점으로부터 수신기까지의 거리를 나타내는 것으로 수학식 5로 표현할 수 있다. A and b of Equation 3 is shown in Equation 4,

Denotes an estimated coordinate estimated by the position of the target. In addition, k _i of Equation 4 represents the distance from the reference point to the receiver can be expressed by Equation 5.

를 얻을 수 있다. Since the matrix A in Equation 3 may not be a square matrix, it can be represented as a square matrix by taking Pseudo-Inverse, and the estimated position coordinate of the target in Equation 6.

Can be obtained.

과

는 각각

의 x와 y의 좌표를 나타낸다. Using the distance information obtained by the TOA technique, the target position can be obtained first by the least square technique. here,

and

Respectively

Represents the coordinates of x and y.

In step 330, the estimation error of the position of the target determined by using the pseudo mono-static information can be reduced. The straight line passing through both the coordinates of the target and the transmitter coordinates obtained by the least square method and the pseudo mono-static information are obtained. This is possible by finding the intersection of the circle with the radius between the transmitter and the target.

라고 하며, 슈도 모노-스태틱 환경에서 얻어지는 거리를

라고 하면, 두 점을 지나는 직선의 방정식과 원의 방정식은 각각 수학식 7, 수학식 8로 표현 할 수 있다.The coordinates of the transmitter

The distance obtained in the pseudo mono-static environment

In other words, the equations of the straight line and the circle passing through two points can be represented by Equation 7, Equation 8, respectively.

The intersection of the straight line and the circle obtained in the step of reducing the estimation error of the position of the target determined using the pseudo mono-static information is two, and the coordinates of the target obtained by the least square method are mapped to one of the two intersections. Can be.

As described, the intersection of Equations 7 and 8 may be derived as two solutions as shown in Equation 9 below.

)를 매핑할 수 있다. 이때, 선택된 하나의 해를

로 나타낸다. The result of Equation 6 calculated by the least-squares method by selecting one suitable solution from two intersection points obtained from

) Can be mapped. In this case, the selected solution

Respectively.

에 가까운 쪽에 다른 하나의 근은

로부터 먼 곳에 존재하게 되고, 따라서 수학식 10과 같이

와 두 개의

와의 거리를 각각 비교하여 작은 것을

로 채택할 수 있다. 다시 말해서, 최소자승기법으로 계산된 판단한 표적의 위치와 가까운 곳에 있는 교점을 선택하여 매핑하는 것이다. 여기서

는 최종적으로 선택된 하나의 교점을 의미한다.When choosing one root, one root

One root on the other side closer to

Far away from it, so

With two

Compare the distance with each other

Can be adopted as. In other words, it selects and maps an intersection near the position of the determined target calculated by the least square method. here

Means one intersection finally selected.

가 항상

보다 정확한 것은 아니다. 이에 대한 일례로 도 4를 참고할 수 있다. But you can get it through

Always

It is not more accurate. As an example of this, reference may be made to FIG. 4.

4 illustrates an example of selectively using pseudo mono-static information and information of a dual separation system. There is one transmitter and three receivers, and when the transmitter transmits a reference signal 401 to a target, Three transmitters and three receivers may receive the reflected signal 402 from the target. Here, the method based on the scheme proposed in the present invention by mapping the estimated coordinate 404 of the target obtained by the least square method on the circle's trajectory 403 which can be estimated as the target when using the pseudo mono-static information. The estimated coordinate 405 can be obtained.

If the estimated coordinates 404 are outside of the circle's trajectory 403, the method-based mapped estimated coordinates 405 may have less error, but in contrast, the estimated coordinates 404 are the circle's trajectories. If present inside 403, there is a possibility that the error will be greater by mapping to the circle's trajectory 403.

Accordingly, in step 340, where the target position is finally determined by comparing pseudo mono-static information with information of the dual separation system, the target is selected by selecting a coordinate closer to the transmitter among the mapped coordinates and the coordinates before the mapping. The error of the estimated coordinates can be reduced.

This step can be seen through the algorithm of FIG. 5. Explain it as a continuation of selecting the intersection to be mapped.

와 매핑되기 이전의 추정좌표, 즉 최소자승기법을 통해 우선적으로 얻은 표적의 추정좌표

중에 송신기와 더 가까이 있는 좌표를 선택할 수 있다. 이는, 송신기에서

점까지의 거리가

점까지의 거리보다 짧은 경우 오히려 오차를 증가시킬 수 있는 가능성이 있기에, 수학식 11과 같이 각 점까지의 거리를 비교하여 더욱 적합한 해를 판별할 수 있다.Estimated coordinates mapped by selecting intersections near the determined targets calculated by the least-squares method

Estimated coordinates before mapping to, i.e., estimated coordinates of targets preferentially obtained by least-squares techniques

You can choose a coordinate closer to the transmitter. At the transmitter

The distance to the point

If it is shorter than the distance to the point, there is a possibility that the error can be increased, so that a more suitable solution can be determined by comparing the distance to each point as shown in Equation (11).

는 송신기에서

점까지의 거리를 의미한다. 도 5의 알고리즘을 참고하여 설명하면, 구해진 Y가 0보다 큰 경우, 즉

가 더 송신기에 가까운 경우에는 표적의 최종 추정 위치로

점을 택할 수 있으며, 반대로 Y가 0보다 작은 경우, 즉

가 더 송신기에 가까운 경우에는 표적의 최종 추정 위치로

점을 택할 수 있다. 이렇게 최종 위치를 판별함으로써 이중분리 레이더 시스템에서 위치 추정의 오차를 최소화할 수 있다. here,

In the transmitter

It means the distance to the point. Referring to the algorithm of FIG. 5, the obtained Y is greater than 0, that is,

Is closer to the transmitter, the final estimated position of the target

Point can be taken, on the contrary, if Y is less than zero,

Is closer to the transmitter, the final estimated position of the target

You can choose a point. By determining the final position in this way, it is possible to minimize the error of the position estimation in the dual separation radar system.

A position estimating system (600) of a dual split radar system, comprising: a target detector (610) for detecting a target for estimating a position; A position estimator 620 for determining a position of a target by a least square method based on a time of argument (TOA); An error reduction unit 630 for reducing an estimation error of the position of the target determined using the pseudo mono-static information; And a position determining unit 640 for finally determining the position of the target by comparing the pseudo mono-static information with the information of the dual separation system.

The position estimation system 600 is a system capable of performing the position estimation method of FIG. 3 proposed in the present invention, and each component of the system is performed by sequentially performing the steps 310 to 340 of the position estimation method. More accurate position estimation can be performed by minimizing the position estimation error in a network-based dual split radar system.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as a hard disk, a floppy disk and a magnetic tape, optical media such as CD-ROM and DVD, magnetic disks such as a floppy disk, - Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents thereof, the appropriate results may be achieved.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

101: Transmitter
102: receiver
103: target
600: location estimation system
610: target detection unit
620: location estimation unit
630: error reduction unit
640: position determination unit

Claims (12)

In the position estimation method of a dual separation radar system,
Detecting a target to estimate a location;
Determining a position of the target by a least square method based on a time of argument (TOA);
Reducing estimation error of the determined position of the target by using pseudo mono-static information; And
Finally determining the position of the target by comparing the pseudo mono-static information with the information of the dual separation system.
/ RTI > The method of claim 1,
The location estimation method is implemented in a dual separation radar system based on a mobile phone network,
The dual separation radar system includes one transmitter and at least three receivers.
Position estimation method characterized in that. 3. The method of claim 2,
The transmitter and the receiver include a device for recognizing its location,
The receiver including a device for measuring an angle of incidence of a signal reflected and transmitted from the target
Position estimation method characterized in that. The method of claim 1,
Determining the position of the target by the least square method based on the time of argument (TOA),
Obtain an equation of the circle according to the number of receivers of the dual separation radar system,
Estimating the intersection of the equation of the circle or a point in the intersection area with the position of the target
Position estimation method characterized in that. 5. The method of claim 4,
The position of the target is estimated by transforming the original equation into a matrix equation and calculating the matrix equation
Position estimation method characterized in that. 5. The method of claim 4,
Reducing the estimation error of the determined position of the target by using the pseudo mono-static information,
A straight line passing through both the coordinates of the target obtained by the least square method and the coordinates of the transmitter,
Finding the intersection of a circle with a radius between the transmitter and the target found as pseudo mono-static information
Position estimation method characterized in that. The method according to claim 6,
The intersection of the straight line and the circle obtained in the step of reducing the estimation error of the determined position of the target using the pseudo mono-static information is two,
Mapping the coordinates of the target obtained by the least square method to one of the two intersections
Position estimation method characterized in that. The method of claim 7, wherein
The intersection point to be mapped among the two intersection points is
Selecting an intersection close to the position of the determined target calculated by the least square method;
Position estimation method characterized in that. The method of claim 7, wherein
In the step of finally determining the position of the target by comparing the pseudo mono-static information and the information of the dual separation system,
Selecting a coordinate closer to the transmitter among the coordinates before mapping with the mapped coordinates
Position estimation method characterized in that. In the position estimation system of a dual split radar system,
A target detector for detecting a target for estimating a position;
A position estimator for determining a position of the target by a least square method based on a time of argument (TOA);
An error reduction unit for reducing an estimation error of the determined position of the target by using pseudo mono-static information; And
Position determination unit for finally determining the position of the target by comparing the pseudo mono-static information and the information of the dual separation system
Position estimation system comprising a. The method of claim 10,
The position estimating unit,
Obtain an equation of the circle according to the number of receivers of the dual separation radar system,
Estimating the intersection of the equation of the circle or a point in the intersection area with the position of the target
Position estimation system, characterized in that. 12. The method of claim 11,
The position of the target is estimated by transforming the original equation into a matrix equation and calculating the matrix equation
Position estimation system, characterized in that.

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