CN101986724B - The localization method of noncooperative target in passive location system based on cellular mobile base stations - Google Patents

Abstract

The present invention relates to the localization method of noncooperative target in a kind of passive location system based on cellular mobile base stations.Specifically include that at least four signal is detectd receiving unit to be arranged in cellular mobile base stations signal coverage areas, receive direct signal and the target reflected signal to base station of base station, determine that the reflected signal of receiving unit and the time difference of direct signal are respectively detectd in arrival, by the position respectively detecing the position of receiving unit, the position of cellular basestation and signal velocity and finally determining target.It is an advantage of the current invention that the Formula Input Technology value of calculated target positions is simple, positioning precision is high, real-time is good.The method of the present invention can also be advantageously applied in the orientation problem that other are similar.

Description

The localization method of noncooperative target in passive location system based on cellular mobile base stations

Technical field

The present invention relates to space target positioning technical field, particularly to a kind of passive location based on cellular mobile base stations The localization method of noncooperative target in system.

Background technology

Passive location system uses double (many) bases based on radio communication and propagation Radar Technology, transmitter and signal Detect receiving unit and be separately positioned on different local, there is anti-interference, Anti-antiradiation missile, anti-low-level penetration and anti-stealthy comprehensive " four resist " potentiality.Use cellular mobile base stations as external sort algorithm, not only saved the energy, decreased electromagnetic pollution, also solved The disguise of double (many) bases radar systems.

Passive location method, by the Method And Principle of realization location, can be divided into position by bearings, time-of-arrival loaction, Doppler's frequency Difference positioning mode and fixed phase variable quantity positioning mode etc..

Time-of-arrival loaction arrives difference according to target to the reflected signal of cellular mobile base stations and detects the relative time of receiving unit Differ from and detect the locus that receiving unit is arranged, list equation by target and the geometrical relationship detectd between receiving unit and ask Solve, the position of available target.Positioning using TDOA positioning mode requires that each signal detects time precise synchronization between receiving unit, has stronger Engineering realizability and higher positioning precision, be therefore widely used in radar, sonar and radiation source alignment system.Actual In application, the observational equation obtained by time-of-arrival loaction is usually nonlinear equation, it will be solved calculating, first has to carry out line Propertyization processes.Conventional method for solving has two kinds: method one is with Chan algorithms based on two step weighted least-squares methods (WLS) Estimating unknown vector, but the method needs to provide the prior information (Q matrix) of TDOA measurement error, this is the most past Toward having certain difficulty, and the target location that the method obtains solves more than one, the problem that there is location ambiguity.Method two is With Taylor Expansion (Taylor-series) by equations turned for non-linear observation for linear equation, then estimated by the method for iteration Unknown vector.The major defect of this method is to need to set an initial value little with physical location deviation to ensure iteration Computing restrains.

Summary of the invention

It is an object of the invention to provide and a kind of be different from the time difference positioning method of target in traditional passive alignment system, should Method determines that the computing formula of target location is succinct, and positioning precision is high, and real-time is good.The method of the present invention is applicable not only to passive In alignment system, it is also possible to be advantageously applied to other similar location technologies.

To achieve these goals, the technical scheme is that

The time difference positioning method of noncooperative target in a kind of passive location system based on cellular mobile base stations, the method is fitted For relevant target location, it comprises the following steps:

(1) have a set of at least four can receive simultaneously at synchronization, the reflection of cellular mobile base stations is believed by target Number and the signal of cellular mobile base stations direct signal detect receiving unit system；

(2) at least four signal of said system is detectd receiving unit to be arranged in cellular mobile base stations signal coverage areas, And the position of the position and cellular mobile base stations respectively detecing receiving unit is known；

(3) receive reflected signal and the direct signal of target, determine that receiving unit reflected signal and direct signal are respectively detectd in arrival The time difference；

(4) according to respectively detecing the position of receiving unit and cellular mobile base stations, determine target arrive respectively detect between receiving unit away from Deviation；

(5) set up coordinate system, derive the computing formula determining target location；

(6) substitution of each known parameters is determined the computing formula of target location, obtains target location with method of least square Initial position, finally determines the three-dimensional position of target by Taylor expansion.

Advantages of the present invention is:

Determining that the computing formula input value of target location is simple, positioning precision is high, real-time is good.The method of the present invention also may be used To be advantageously applied in other similar orientation problems.

Accompanying drawing explanation

Fig. 1 is the positioning principle schematic diagram of invention；

Fig. 2 is the localization method flow chart of the present invention.

Detailed description of the invention

Below by embodiment, and combine accompanying drawing, the technical method of the present invention is further described.

Embodiment: shown in Figure 1, detects receiving unit by least four signal and is arranged in honeycomb according to certain geometric distribution The overlayable region of mobile base station signal, and measure the position (X respectively detecing receiving unit_i, Y_i, Z_i) and the position of cellular mobile base stations Put (X₀, Y₀, Z₀).When there being target to enter into search coverage, target is straight to the reflected signal of cellular mobile base stations and this base station Reach signal and respectively detectd receiving unit reception simultaneously, detect receiving unit measurement and obtain step-out time TDOA of this two paths of signals_iIf, electromagnetic wave Spread speed be c, the position to be determined of target be (x, y, z).Make R_{I, 1}Represent target and receive station i with detecing and detect the distance at receipts station 1 Difference, then

$\left\{\begin{array}{c}{R}_{i,1}=c\·({\mathrm{TDOA}}_i-{\mathrm{TDOA}}_1)+(r_i-r_1)=R_i-R_1\\ =\sqrt{{(X_i-x)}^2+{(Y_i-y)}^2+{(Z_i-z)}^2}-\sqrt{{(X_1-x)}^2+{(Y_1-y)}^2+{(Z_1-z)}^2}---\left(1\right)\\ r_i=\sqrt{{(X_i-X_0)}^2+{(Y_i-Y_0)}^2+{(Z_i-Z_0)}^2}---\left(2\right)\end{array}\right..$

I=1,2,3,4, c represent propagation velocity of electromagnetic wave.Above formula abbreviation arranges

(X₁-X_i)x+(Y₁-Y_i)y+(Z₁-Z_i) z=k_i+R₁·R_{I, 1} (3)

In formulaThe equation represented by formula (3) constitutes one Individual Nonlinear System of Equations, in order to solve this equation group, first by R₁Regard a known quantity as, it is hereby achieved that a matrix Expression formula is as follows

AX=F (4)

In formula

$A=\left[\begin{array}{ccc}{X}_1-X_2& Y_1-Y_2& Z_1-Z_2\\ X_1-X_3& Y_1-Y_3& Z_1-Z_3\\ X_1-X_4& Y_1-Y_4& Z_1-Z_4\end{array}\right],$ $X=\left[\begin{array}{c}x\\ y\\ z\end{array}\right],$ $F=\left[\begin{array}{c}{k}_2+R_1\·R_{\mathrm{2,1}}\\ k_3+R_1\·R_{\mathrm{3,1}}\\ k_4+R_1\·R_{\mathrm{4,1}}\end{array}\right]$

As long as four are detectd receiving unit the most at grade, just there is rank (A)=M-1, solve a young waiter in a wineshop or an inn of X in formula (4) Take advantage of solution,

$\hat{X}={\left(\begin{array}{cc}{A}^T& A\end{array}\right)}^{-1}{A}^{T}F---\left(5\right)$

The X now obtained is by R₁Represent, order

${\left(\begin{array}{cc}{A}^T& A\end{array}\right)}^{-1}{A}^T=\left[\begin{array}{cccc}{a}_{11}& a_{12}& \·\·\·& a_{1M-1}\\ a_{21}& a_{22}& \·\·\·& a_{2M-1}\\ a_{31}& a_{32}& \·\·\·& a_{3M-1}\end{array}\right]={\left[a_{\mathrm{ij}}\right]}_{3\×(M-1)}---\left(6\right)$

Can be obtained by (5)

$\left\{\begin{array}{c}\hat{x}=m_1+n_1\·R_1\\ \hat{y}=m_2+n_2\·R_1\\ \hat{z}=m_3+n_3\·R_1\end{array}\right.---\left(7\right)$

Wherein

$\left\{\begin{array}{c}a=\underset{i=1}{\overset{3}{\mathrm{\Σ}}}{n}_i^2-1\\ b=2[n_1(m_1-X_1)+n_2(m_2-Y_1)+n_3(m_3-Z_1)]\\ c={(m_1-X_1)}^2+{(m_2-Y_1)}^2+{(m_3-Z_1)}^2\end{array}\right.$

Solve

$R_1=\frac{-b\±\sqrt{b^2-4\mathrm{ac}}}{2a}---\left(8\right)$

Again it is taken back above formula, using the target location that obtains as initial position (x₀, y₀, z₀), and by formula (1) in target Initial position carries out Taylor expansion, neglects second order and above component, is converted to

ψ=h_t-G_tδ (9)

Wherein

$h_t=\left[\begin{array}{c}{R}_{\mathrm{2,1}}-(R_2-R_1)\\ R_{\mathrm{3,1}}-(R_3-R_1)\\ R_{4,1}-(R_4-R_1)\end{array}\right],\mathrm{\δ}=\left[\begin{array}{c}\mathrm{\Δx}\\ \mathrm{\Δy}\\ \mathrm{\Δz}\end{array}\right]$

$G_t=\left[\begin{array}{ccc}\frac{(X_1-x_0)}{R_1}-\frac{(X_2-x_0)}{R_2}& \frac{(Y_1-y_0)}{R_1}-\frac{(Y_2-y_0)}{R_2}& \frac{(Z_1-z_0)}{R_1}-\frac{(Z_2-z_0)}{R_2}\\ \frac{(X_1-x_0)}{R_1}-\frac{(X_3-x_0)}{R_3}& \frac{(Y_1-y_0)}{R_1}-\frac{(Y_3-y_0)}{R_3}& \frac{(Z_1-z_0)}{R_1}-\frac{(Z_3-z_0)}{R_3}\\ \frac{(X_1-x_0)}{R_1}-\frac{(X_4-x_0)}{R_4}& \frac{(Y_1-y_0)}{R_1}-\frac{(Y_4-y_0)}{R_4}& \frac{(Z_1-z_0)}{R_1}-\frac{(Z_4-z_0)}{R_4}\end{array}\right]$

R_i(i=1,2,3,4) is target initial position and the distance respectively detectd between receiving unit.The weighting of formula (9) young waiter in a wineshop or an inn (WLS) solution is taken advantage of to be

$\mathrm{\δ}=\left[\begin{array}{c}\mathrm{\Δx}\\ \mathrm{\Δy}\\ \mathrm{\Δz}\end{array}\right]={\left(G_t^T{G}_t\right)}^{-1}{G}_t^T{h}_t---\left(10\right)$

It is iterated computing, each time in iteration, order More than repetition Process, until Δ x, Δ y, Δ z is sufficiently small, meets the thresholding of a setting, as

| Δ x |+| Δ y |+| Δ z | ＜ ε (11)

Now obtainIt is final target location.

In the present invention, use method based on least square that target initial position is estimated, it is ensured that iteration meter Convergence in calculation, and accelerate convergence rate, then make initial position continuous approaching to reality position by interative computation, Improve the positioning precision of target.

Claims (1)

1. a time difference positioning method for noncooperative target in passive location system based on cellular mobile base stations, the method is suitable for In relevant target location, it comprises the following steps:

(1) have a set of at least four can receive simultaneously by target synchronization to the reflected signal of cellular mobile base stations with And the signal of cellular mobile base stations direct signal detects receiving unit system；

(2) at least four signal of said system is detectd receiving unit to be arranged in cellular mobile base stations signal coverage areas, and The position of the position and cellular mobile base stations of respectively detecing receiving unit is known；

(3) receive the reflected signal of target and direct signal, determine arrive respectively detect receiving unit reflected signal and direct signal time Difference；

(4) basis respectively detects the position of receiving unit and cellular mobile base stations, determines that target arrives and respectively detects the distance between receiving unit Difference；

(5) set up coordinate system, derive the computing formula determining target location；

(6) substitution of each known parameters is determined the computing formula of target location, obtains the initial of target location with method of least square Position, finally determines the three-dimensional position of target by Taylor expansion.