KR101280513B1 - Localization method based on gauss-netwon method using tdoa/fdoa, and localization apparatus using the same - Google Patents

Abstract

PURPOSE: A signal source location estimating method and a signal source location estimating apparatus using the same are provided to simultaneously use time difference of arrival (TDOA) and frequency difference of arrival (FDOA), thereby improving the accuracy of location estimation. CONSTITUTION: A signal source location estimating method includes following steps. A location and speed vector estimation value about the location and speed vector of a radar signal source is set, and an initial value about transmission value is set (S110). A TDOA and FDOA estimation value is calculated using the location and speed vector estimation value and the transmission value set by the initial value (S120). A difference value between a TDOA and FDOA measurement value measured in a receiving part and the TDOA and FDOA estimation value is calculated (S130). A Jacobian matrix is generated by differentiating each of a TDOA model equation and an FDOA model equation which are prepared in advance using the TDOA and FDOA estimation value (S140). A weighted value for altering the location and speed vector estimation value is calculated using the difference value and the Jacobian matrix, and the location and speed vector estimation value is altered using the weighted value (S150). In case the difference value is higher than a permissible threshold value or the repeated number of control procedures in previous steps is lower than a maximum value, the control procedures in the previous steps are performed again (S160). If the difference value is lower than the permissible threshold value and the repeated number of the control procedures is higher than the maximum value, an altered location and speed vector estimation value is determined as a final location speed vector of the radar signal source (S170). [Reference numerals] (AA) Start; (BB) End; (S110) Set an initial value; (S120) Calculate a TDOA and FDOA estimation value; (S130) Calculate the difference value between a TDOA and FDOA measurement value and the TDOA and FDOA estimation value; (S140) Generate a Jacobian matrix; (S150) Alter the location and speed vector estimation value; (S160) Confirm whether the difference value is higher than a permissible threshold value; (S170) Determine the location and speed

Description

Source location estimation method based on Gauss-Newton technique using TDOA / FDOA and localization method based on Gauss-Netwon method using TDOA / FDOA, and Localization apparatus using the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for estimating a signal source, and more particularly, to a signal source estimating method for detecting and identifying a signal in an electronic warfare and a signal source estimating apparatus using the same.

Methods of estimating the position of the signal source include a method of using Angle of Arrival (AOA), a method of using Time Difference of Arrival (TDOA), and a method of using Frequency Difference of Arrival (FDOA).

In the method of estimating the position of a signal source using AOA, the position estimation performance is determined according to the direction detection accuracy of each antenna and the ratio of the distance between the antennas and the distance of the signal source. However, considering the cost to improve the direction accuracy, the method of estimating the position of the signal source using AOA is not suitable for the place where high accuracy is required.

The location estimation method using TDOA or FDOA alone shows high accuracy, but the location accuracy is poor due to the geometrical dilution of precision (GDOP) due to the geometrical arrangement such as antenna placement and threat location.

KR 10-0979294 B, 2010. 08. 31, FIG. 1

Disclosure of Invention An object of the present invention is to provide a signal source location estimation method and a signal source location estimation apparatus using the same that can improve the accuracy of location estimation by using a time difference of arrival (TDOA) and frequency difference of arrival (FDOA) simultaneously. .

One aspect of the present invention for achieving the above object relates to a signal source position estimation method applied to the detection and identification of signals in electronic warfare, the present signal source position estimation method (a) the position of the radar signal source Setting a position / velocity vector estimated value for and a velocity vector and an initial value for a transmission frequency; (b) calculating TDOA and FDOA estimates using the position / speed vector estimate and the transmission frequency set as the initial value; (c) calculating a difference between the TDOA and FDOA measurement values measured by the receiver and the TDOA and FDOA estimates, and using the TDOA and FDOA estimates to differentiate the TDOA model equations and the FDOA model equations prepared in advance, respectively. Generating a matrix; (d) calculating a weight for changing the position / velocity vector estimate using the difference value and the Jacobian matrix and changing the position / velocity vector estimate using the weight; (e) control from (a) to (d) when the difference value is larger than the allowable threshold value or the number of repetitions of the control procedure from step (a) to step (d) is less than or equal to the maximum value; Performing the procedure again; And (f) if the difference value is less than or equal to the allowable threshold value or the repetition frequency of the control procedure is greater than the maximum value, the estimated value of the position / velocity vector changed by step (d) is converted into the final position / velocity vector of the radar signal source. Characterized in that it comprises the step of determining.

In the position / velocity vector estimate, the position vector estimate is (x _e , y _e ), the velocity vector estimate is (v _xe , v _ye ), the TDOA model equation is f ^τ (x), and the FDOA model equation is If f ^v (x) and the number of receiver pairs in the receiver is N, the Jacobian matrix may be generated by Equation 1.

Equation 1:

E, the position / velocity vector estimate, is represented by Equation 2, and the difference between the TDOA and FDOA measurements and the TDOA and FDOA estimates is represented by Δe, the time measurement error is σ _t, and the frequency measurement error is σ _f . When the measurement error matrix R formed is represented by Equation 3, the weight Δx may be represented by Equation 4.

Equation 2:

Equation 3:

Equation 4:

The final position / velocity vector determined in step (f) may be expressed by Equation 5 when the final position vector is (P _x , P _y ) and the final velocity vector is (V _x , V _y ).

Equation 5:

Signal source position estimation apparatus according to another aspect of the present invention for achieving the above object comprises a receiving unit including three or more receiving end for detecting a signal from the outside; And a controller for performing a signal source position estimation method according to an aspect of the present invention based on the information detected and processed by the receiver.

As described above, the object of the present invention is to improve the accuracy of the estimation of the position of the signal source by simultaneously using the Time Difference of Arrival (TDOA) and the Frequency Difference of Arrival (FDOA).

In addition, the present invention can also obtain the velocity vector (speed, direction) information in the case of a moving signal source, it can be applied to any system that requires monitoring system and signal source position / velocity estimation.

1 is a flowchart illustrating a signal source position estimation method according to an embodiment of the present invention.
2 is a graph illustrating a TDOA / FDOA position estimation result when only two antennas among three antennas are used in the signal source position estimation method according to an embodiment of the present invention.
3 is a graph illustrating a TDOA / FDOA position estimation result when three antennas are used in the signal source position estimation method according to an embodiment of the present invention.
4 is a block diagram of a signal source position estimation apparatus according to another embodiment of the present invention.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail with reference to the drawings. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Should not.

A signal source estimation method according to an embodiment of the present invention calculates a time difference of arrival (TDOA) and a frequency difference of arrival (FDOA) using the time of arrival (TOA) and frequency information of a received pulse. This method estimates the position of signal source based on Gauss-Newton technique.

The Gauss-Newton method is a method of repeatedly solving the nonlinear LS problem by linear LS problem through Taylor's series expansion. In the present invention, a nonlinear signal model for TDOA and FDOA is used. We correct the linear LS problem and estimate the position and velocity values repeatedly.

1 is a flowchart illustrating a signal source position estimation method according to an embodiment of the present invention.

Referring to FIG. 1, the signal source estimation method includes setting an initial value (S110), calculating a position and velocity estimation value based on the initial value (S120), and calculating a difference between the measured value and the estimated value ( S130), generating a Jacobian matrix based on the estimated value (S140), changing the estimated value through a Jacobian matrix operation (S150), and determining whether to converge (S160). have.

First, the step of setting the initial value (S110) is to set the position / speed vector estimate value for the position and velocity vector of the radar signal source and to set the initial value for the transmission frequency. E). Any value, E, is a matrix consisting of [estimated position on the X axis, estimated position on the Y axis, estimated speed on the X axis, estimated speed on the Y axis].

In addition, the initial value setting for the transmission frequency may be set to an average value of the frequency information obtained by being detected by the receiver. This can be used for the calculation of FDOA.

In calculating the TDOA and FDOA estimates (S120), the TDOA and FDOA estimates are calculated using the position / speed vector estimate and the transmission frequency set as the initial value.

The step of calculating the difference between the TDOA and FDOA measurement value and the estimated value (S130) is a step of calculating the difference value Δe between the TDOA and FDOA measurement value measured by the receiver and the TDOA and FDOA estimated value calculated in step S120.

로 표현되고, 여기서 c는 빛의 속도(2.99792458×10⁸m/s)이고, x_e,y_e는 신호원의 추정 위치이며, x_i,y_i는 수신단 i의 위치이고, x_j,y_j는 수신단 j의 위치이다. 또한 FDOA 모델 방정식 f^v(x)는 수신단 i, 수신단 j에 대해 수식

로 표현되고, 여기서 f_e는신호원에 대한 측정주파수이고, c는 빛의 속도(2.99792458×10⁸m/s)이며, x_e,y_e는 신호원의 추정 위치이며, x_i,y_i는 수신단 i의 위치이고, x_j,y_j는 수신단 j의 위치이며, v_xi,v_yi는 수신단 i의 속도벡터(x좌표, y좌표)이고, v_xj,v_yj는 수신단 j의 속도벡터이다.The Jacobian matrix generation step S140 generates a Jacobian matrix by differentiating a previously prepared TDOA model equation and an FDOA model equation using TDOA and FDOA estimates. The TDOA model equations f ^τ (x) and the FDOA model equations f ^v (x) used known equations. As an example of a known equation, the TDOA model equation f ^τ (x) described in Finding Optimal Trajectory Points for TDOA / FDOA Geo-Location Sensors (Information Sciences and Systems, 2009, CISS 2009, 43 ^rd Annual Conference) is defined as the receiver i, the receiver j. Formula for

Where c is the speed of light (2.99792458 × 10 ⁸ m / s), x _e , y _e is the estimated position of the signal source, x _i , y _i is the position of the receiver i, x _j , y _j is the position of the receiving end j. In addition, the FDOA model equation f ^v (x) is the equation for receiver i and receiver j.

Where f _e is the measurement frequency for the signal source, c is the speed of light (2.99792458 × 10 ⁸ m / s), x _e , y _e is the estimated location of the signal source, x _i , y _i Is the position of the receiver i, x _j , y _j is the position of the receiver j, v _xi , v _yi is the velocity vector (x coordinate, y coordinate) of the receiver i, v _xj , v _yj is the velocity vector of the receiver j to be.

If the TDOA model equation is f ^τ (x), the FDOA model equation is f ^v (x), the estimated position vector is (x _e , y _e ), and the velocity vector is (v _xe , v _ye ), then Jacobian ) Matrix is shown in Equation 2 below. In Equation 2, N denotes the number of antenna pairs equal to the antenna of the receiver to be used. The antennas are spaced apart from each other to detect a radio wave from the outside.

In the step S150 of changing the position / velocity estimate, a weight Δx to change the estimate of the position / velocity vector is calculated using Δe, which is a difference between the Jacobian matrix, the TDOA and FDOA measurements, and the TDOA and FDOA estimates. . Δx may be expressed as in Equation 3.

In Equation 3, R is a diagonal matrix of length N vs. N composed of time measurement error (σ _t ) and frequency measurement error (σ _f ). R may be expressed as in Equation 4.

The position / speed estimation value changing step (S150) may change the estimated value of the position / speed vector by reflecting the weight Δx as described above. The estimated value of the changed position / velocity vector may be represented by the position vector (P _x , P _y ) and the velocity vector (V _x , V _y ), and the matrix [P _x , P _y , V _x , V _y ] may be expressed as Equation 5.

The convergence check step S160 determines whether to repeat the control procedure from step S110 to step S150 using the allowable threshold value θ and the maximum repetition allowance number MAX_ITER. The Δe value, which is the difference between the TDOA and FDOA measured values calculated in step S130 and the TDOA and FDOA estimated values, is greater than the allowable threshold value (θ) or the maximum number of iterations of the control procedure from step S110 to step S150 (MAX_ITER). In the following case, the control procedure from step S110 to step S150 based on the Gauss-Newton method is performed again.

The position / speed estimation value determining step (S170) may be performed from step S110 when the result of the step S160 indicates that the value Δe is less than or equal to the allowable threshold value (θ) or the number of iterations of the control procedure from step S110 to step S150 is greater than a predetermined maximum value MAX_ITER. The control procedure up to step S150 is terminated, and the matrix [P _x , P _y, V _x , V _y ], which is an estimated value of the position / velocity vector changed in step S150, is determined as the final position / velocity vector of the radar signal source.

2 is a graph illustrating a TDOA / FDOA position estimation result when only two antennas of three antennas are used in the signal source position estimation method according to an embodiment of the present invention, and FIG. In the signal source position estimation method according to the embodiment, it is a graph for explaining the TDOA / FDOA position estimation result when only three antennas are used.

With reference to FIG. 2, the TDOA / FDOA position estimation result when only two antennas are used is demonstrated. As shown in Fig. 2, the graph indicated by A indicates the position of the radar signal source estimated by the TDOA, and the graph indicated by B indicates the position of the signal source estimated by the FDOA. The intersection of the graphs of A and B corresponds to the position of the radar signal source estimated when TDOA and FDOA are applied simultaneously.

Referring to FIG. 3, the TDOA / FDOA position estimation result when only three antennas are used will be described. As shown in Fig. 3, the graph indicated by A indicates the position of the radar signal source estimated by the TDOA, and the graph indicated by B indicates the position of the signal source estimated by the FDOA. The intersection of the graphs of A and B corresponds to the position of the radar signal source estimated when TDOA and FDOA are applied simultaneously.

4 is a functional block diagram of a signal source position estimating apparatus according to another embodiment of the present invention.

Hereinafter, a signal source position estimation apparatus according to another embodiment of the present invention will be described with reference to FIG. 4. The signal source position estimation method 1 according to the present embodiment may be operated by the signal source position estimation method described above, and may be operated by the receiver 10 for sensing an external signal and the signal source position estimation method described above. The control unit 20 may include.

The receiver 10 includes three or more antennas to detect radio signals such as an external radar signal, and the antennas may be spaced apart from each other by three or more. The receiver 10 processes the signal detected through the antenna and transmits the signal to the controller 20.

When the radar signal is detected, the receiver 10 may measure a carrier frequency, a pulse width, a pulse amplitude, a time of arrival, and the like of the signal. have.

The control unit 20 functionally calculates the TDOA and FDOA estimated value module 22, the TDOA and FDOA measured value and the estimated value difference module 24, and Jacobian as shown in FIG. Jacobian) may be divided into a matrix generation module 25, a position / speed estimation value change module 27 of a signal source, and a position / speed determination module 29 of a signal source.

The TDOA and FDOA estimate calculation module 22 sets position / velocity vector estimates for the position and velocity vectors of the signal source and initial values for the transmission frequency. The position and velocity vector of the signal source may be set to any value as in Equation 1.

The TDOA and FDOA estimate calculation module 22 may set an initial value for the transmission frequency by using an average value of the frequency information detected and acquired by the receiver 10.

The TDOA and FDOA estimate calculation module 22 calculates the TDOA estimate and the FDOA estimate by using the position / speed vector estimate value represented by Equation 1 and the transmission frequency set as the initial value.

The difference between the TDOA and FDOA measured value and the estimated value calculation module 24 is the difference between the TDOA and FDOA measured values detected by the receiver 10 and the TDOA and FDOA estimated value calculated module 22 and calculated (Δe). Calculate

The Jacobian matrix generation module 25 differentiates the TDOA and FDOA model equations using the TDOA and FDOA estimates to generate a Jacobian matrix as shown in Equation (2).

The source / position estimation value change module 27 of the signal source uses a Jabbian matrix, TDOA and FDOA measurement values, and Δe, which is a difference value between the TDOA and FDOA estimates, to change the position / speed vector estimate value (Δx). ) Is calculated as in Equation 3.

The position / speed estimation value change module 27 of the signal source may change the position / speed vector estimate value by reflecting the weight Δx calculated as in Equation 3. The estimated value ([P _x , P _y, V _x , V _y ]) of the changed position / velocity vector may be expressed as in Equation 5.

The position / speed estimation value determining module 29 determines the number of control operations for changing the position / speed vector estimate value or the? E value calculated by the TDOA and FDOA measured value and the estimated value difference calculation module 24 is less than or equal to the allowable threshold value [theta]. Is larger than the predetermined maximum value MAX_ITER, the control operation for changing the estimated value of the position / velocity vector is terminated, and [P], which is an estimated value of the position / velocity vector changed by the position / velocity estimation value change module 27 of the signal source, is changed. _x , P _y, V _x , V _y ] is determined as the final position / speed vector of the signal source.

 As described above, the signal source position estimation method and the signal source position estimation apparatus 1 according to an embodiment of the present invention solve the ambiguity of the position estimation caused by using TDOA or FDOA alone by simultaneously using the TDOA and the FDOA signal. If the circle is moving, velocity vectors (velocity, direction) are also available, so it can be directly applied to any system that requires surveillance and signal source position / speed estimation.

The present invention can be applied to various applications in the field of signal detection and identification of electronic warfare in addition to the embodiments described above.

1: signal source estimation device
10: receiver
20: control unit
22: TDOA and FDOA Estimation Calculation Module
24: TDOA and FDOA measured and estimated difference calculation module (24)
25: Jacobian matrix generation module
27: position / speed estimation value change module of the signal source
29: Position / speed determination module of the signal source

Claims (5)

In the signal source position estimation method applied to the detection and identification of signals in electronic warfare,
(a) setting position / velocity vector estimates for the position and velocity vectors of the radar signal source and initial values for the transmission frequency;
(b) calculating TDOA and FDOA estimates using the position / speed vector estimate and the transmission frequency set as the initial value;
(c) calculating the difference between the TDOA and FDOA measurements measured by the receiver and the TDOA and FDOA estimates, and using the TDOA and FDOA estimates to differentiate the TDOA model equations and the FDOA model equations prepared in advance, respectively. Generating a matrix;
(d) calculating a weight for changing the position / velocity vector estimate using the difference value and the Jacobian matrix and changing the position / velocity vector estimate using the weight;
(e) control from (a) to (d) when the difference value is larger than the allowable threshold value or the number of repetitions of the control procedure from step (a) to step (d) is less than or equal to the maximum value; Performing the procedure again; And
(f) If the difference is less than the allowable threshold or the number of repetitions of the control procedure is greater than the maximum value, the estimated value of the position / velocity vector changed by the step (d) is determined as the final position / velocity vector of the radar signal source. Signal source position estimation method comprising the step of.
The method of claim 1,
In the position / velocity vector estimate, the position vector estimate is (x _e , y _e ), the velocity vector estimate is (v _xe , v _ye ), the TDOA model equation is f ^τ (x), and the FDOA model equation is If f ^v (x) and the number of antenna pairs in the receiver is N, the Jacobian matrix is generated by Equation 1.
Equation 1:

The method of claim 2,
E, the position / velocity vector estimate, is represented by Equation 2, and the difference between the TDOA and FDOA measurements and the TDOA and FDOA estimates is represented by Δe, the time measurement error is σ _t, and the frequency measurement error is σ _f . When the measurement error matrix R is formed by Equation 3, the weight Δx is represented by Equation 4.
Equation 2:

Equation 3:

Equation 4:

The method of claim 3,
The final position / velocity vector determined in the step (f) is represented by Equation 5 when the final position vector is (P _x , P _y ) and the final velocity vector is (V _x , V _y ). Source location estimation method.
Equation 5:

A receiver including three or more antennas for sensing a signal from the outside; And
And a control unit for performing the signal source position estimation method according to any one of claims 1 to 4, based on the information detected and processed by the receiver.

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