CN105487072A - Method and system of joint location based on T2/R time difference and Doppler shift - Google Patents

Abstract

The present invention discloses a method and system of joint location based on T2/R time difference and Doppler shift. The method comprises the following steps: S1, selecting two shortwave broadcasting stations with different signal frequencies as launch stations, obtaining their emission frequencies and coordinate positions, and calculating the big circle distances of the ground between the launch stations and an accepting station; S2, calculating the time difference data and Doppler shift data between a direct wave and a scattered wave according to the signal frequencies and the big circle distances of the ground; S3, jointing the obtained time difference data and the Doppler shift data to obtain an estimating equation of a target state, and obtaining a convergence result through calculation according to batch algorithms, namely the position and the flight speed of a flying target. Only two broadcasting stations are needed to be taken as sources of radiation to locate a moving aerial target, so that the aspects of the position precision and the speed precision are greatly improved for the targets in a uniform motion and a variable motion.

Description

A kind of based on T 2the time difference of/R and Doppler shift combined positioning-method and system

Technical field

The present invention relates to signal transacting field, particularly relate to a kind of based on T ²the time difference of/R and Doppler shift combined positioning-method and system.

Background technology

Target localization is at present at military field, moving communicating field, medical domain, and civil area etc. all have very important realistic meaning.And Rainles day technology, because system does not initiatively transmit, only rely on the electromagnetic signal receiving and reflected by localizing objects, determine its locus, the important directions of future development especially.

In recent years, in Rainles day system, general many based on arrival direction angle (DOA), time of arrival (TOA), step-out time (TDOA), Doppler frequency, signal intensity (RSSI) and various associated form, target is positioned.Because the time difference is only relevant to target location, the simple and position positioning precision of positioning equation, higher than the target arrival bearing angle of arrival, adopts positioning using TDOA therefore more.But in general system needs 3 and above cell site mostly, and for random moving target, because the time difference and motion state relation are little, therefore utilize positioning using TDOA system can exist fuzzy to target speed estimation.Li Wanchun 2005 propose based on two cell site, utilize time difference information to position target, not independent speed positioning precision and result to be assessed, and when target (N=20) uniform motion within a very long time.And Doppler shift is owing to being closely related with motion state, can well estimate target velocity, the only employing Doppler shift that Xiao Yang proposes for bright 2011 positions target location and velocity information, when cell site's number reaches 4 time, position positioning precision has just had significant raising, and same hypothetical target is uniform motion in 30s.But under actual conditions, target is not generally at the uniform velocity constant, remains unchanged in other words within the quite a long time.Therefore, consider that the target of variable motion has more actual meaning.

Summary of the invention

The technical problem to be solved in the present invention is the state for only considering uniform motion in prior art in Rainles day system, and the defect that the cell site's quantity needed is too much, one is provided only to need Liang Ge cell site, and can be pinpoint based on T to the target of variable motion ²the time difference of/R and Doppler shift combined positioning-method and system.

The technical solution adopted for the present invention to solve the technical problems is:

The invention provides a kind of based on T ²the time difference of/R and Doppler shift combined positioning-method, comprise the following steps:

The shortwave broadcasting radio station of S1, selection two unlike signal frequencies, as cell site, obtains their transmission frequency and coordinate position, and calculates the ground great-circle distance between cell site and receiving station according to coordinate position;

S2, use time difference measurement method according to signal frequency and ground great-circle distance, calculate the time difference data between direct wave and scattering wave and doppler shift data, wherein, direct wave is cell site's signal that receiving station directly receives, and scattering wave is transmit to be irradiated to the signal that airflight target back reflection arrives receiving station;

The time difference data that S3, basis obtain and doppler shift data are combined, and obtain Target state estimator equation, and calculate convergence result by batch algorithms, be position and the flying speed of airbound target.

Further, the method obtaining shortwave broadcasting radio station transmission frequency and coordinate position in step S1 of the present invention is:

The short-wave all-frequency band radio frequency issued from International Telecommunications Union (ITU) divides list, and select Liang Ge cell site, cell site can not coexist on a coordinate position with receiving station, and two shortwave broadcasting signals adopt AM modulation system, and are different frequency short-wave signal.

Further, step S2 of the present invention specifically comprises the following steps:

S21, extraction direct-path signal, this direct wave is cell site's signal that receiving station directly receives;

S22, extract scattering wave signal, this signal is that after cell site transmits and is irradiated to air mobile target, reflection arrives the signal of receiving station;

S23, the time difference information utilizing TDOA estimation algorithm to obtain between continuous k direct wave and scattering wave;

S24, the Doppler shift information utilizing Doppler frequency estimation algorithm to obtain between continuous k direct wave and scattering wave.

Further, step S3 of the present invention specifically comprises the following steps:

S31, calculating time difference measurement equation are to the Jacobi matrix of target initial state vector;

S32, calculating Doppler shift measurement equation are to the Jacobi matrix of target initial state vector;

S33, carry out Combined Treatment to the result of calculation of step S31 and step S32, two matrixes being about to obtain carry out combination and obtain Target state estimator equation, and its formula is:

$H_k\left(X_0\right)=\frac{\∂h\left(X\right)}{\∂X_0}=\[\begin{array}{cc}\frac{\∂T_{jk}}{\∂X_0}& \frac{\∂F_{jk}}{\∂X_0}\end{array}\],k=1,2,...N$

Wherein, represent that time difference measurement equation is to the Jacobi matrix of target initial state vector, represent that Doppler shift measurement equation is to the Jacobi matrix of target initial state vector;

S34, utilize batch algorithms to solve it, when algorithm convergence, finally obtain maneuvering target positional information and velocity information.

Further, in step S31 of the present invention, the computing method of target initial state vector are:

X ₀＝[[x ₀y ₀v _xv _y]] ^T

Wherein, X ₀for target initial state vector, (x ₀, y ₀) be target initial position, (v _x, v _y) be the component of target velocity in x, y-axis, [] ^tfor operating transpose of a matrix;

In the kth time moment, target uniform motion speed is (v _x, v _y), then known target location:

x _k＝x ₀+kΔtv _x；

y _k＝y ₀+kΔtv _y；

Wherein, Δ t is sampling interval duration.

Further, in step S31 of the present invention, time difference measurement equation is:

${\mathrm{\τ}}_{jk}=\frac{1}{c}\[r_{jk}+r_{0k}-R_{trj}\],(k=0,1,2,...,N),(j=1,2)$

Wherein, τ _jkrepresent the time difference that jGe cell site kth time obtains, c represents the light velocity, r _jk, r _0k, R _trjrepresent the distance between cell site j and target respectively, the distance between target and receiving station and the distance between cell site j and receiving station;

First cell site is positioned at (x _t1, y _t1), second cell site is positioned at (x _t2, y _t2), receiving station is positioned at (x _r, y _r), and have:

$r_{jk+i}=\sqrt{({\left(x_k-x_{jT}\right)}^2+{\left(y_k-y_{Tj}\right)}^2)}$

$r_{0k+i}=\sqrt{({\left(x_k-x_R\right)}^2+{\left(y_k-y_R\right)}^2)}$

$R_{trj}=\sqrt{({\left(x_R-x_{Tj}\right)}^2+{\left(y_R-y_{Tj}\right)}^2)}$

Wherein, k=0,1,2 ..., N.

Further, in step S32 of the present invention, Doppler shift measurement equation is:

$f_{jk}=\frac{f_j}{c}.\left(-\frac{\left(\left(x_k-x_{Tj}\right)v_x+\left(y_k-y_{Tj}\right)v_y\right)}{\sqrt{{\left(x_k-x_{Tj}\right)}^2+{\left(y_k-y_{Tj}\right)}^2}}-\frac{\left(\left(x_k-x_R\right)v_x+\left(y_k-y_R\right)v_y\right)}{\sqrt{{\left(x_k-x_R\right)}^2+{\left(y_k-y_R\right)}^2}}\right)$

F _jrepresent jGe cell site emission signal frequency.

Further, the concrete grammar of batch algorithms is used to be in step S34 of the present invention:

Target component actual value is made to be X ₀, estimates of parameters is measure equation and can be written as general type:

Z＝h(X)+n

N is noise, by it to X ₀place makes Taylor series expansion, and the once item of only decimation stage Number Sequence, then:

$Z=h\left(X_0\right)+H(\hat{X}-X_0)+n$

$H_k\left(X_0\right)=\frac{\∂h\left(X\right)}{\∂X_0}=\[\begin{array}{cc}\frac{\∂T_{jk}}{\∂X_0}& \frac{\∂F_{jk}}{\∂X_0}\end{array}\],k=1,2,...N$

Above formula be about linear equation, can process with linear least square, then have:

$\hat{X}=X_0+{\left(H^T{S}_k^{-1}H\right)}^{-1}{H}^T{S}_k^{-1}(Z-h(X_0\left)\right)$

Wherein as the initial value of successive approximation method converging on optimal estimation value;

By Gauss-Newton method, can obtain:

${\hat{X}}_{n+1}={\hat{X}}_n-m{\left(H^T{S}_k^{-1}H\right)}^{-1}{H}^T{S}_k^{-1}(Z-h({\hat{X}}_n\left)\right)$

Wherein for latest estimated value, be n-th time iterative estimate value, m is converging factor, gets the value being similar to 1;

When then think that algorithm is restrained, then net result is target position information and velocity information.

The invention provides a kind of based on T ²the time difference of/R and Doppler shift co-located system, comprising:

Frequency and distance acquiring unit, for selecting the shortwave broadcasting radio station of two unlike signal frequencies as cell site, obtain their transmission frequency and coordinate position, and calculate the ground great-circle distance between cell site and receiving station according to coordinate information;

The time difference and doppler shift data computing unit, for using time difference measurement method according to signal frequency and ground great-circle distance, calculate the time difference data between direct wave and scattering wave and doppler shift data, wherein, direct wave is cell site's signal that receiving station directly receives, and scattering wave is transmit to be irradiated to the signal that airflight target back reflection arrives receiving station;

Co-located unit, for according to the time difference data obtained and doppler shift data co-located, calculates position and the flying speed of airbound target.

The beneficial effect that the present invention produces is: of the present invention based on T ²the time difference of/R and Doppler shift combined positioning-method, only need two broadcasting stations as radiation source, just can position the aerial target of movement; By adopting the time difference information between direct wave and scattering wave, decreasing the number required for cell site, being conducive to the quick foundation of shortwave rader system; And adopt time difference information and Doppler shift information, to the target of uniform motion and variable motion, positional precision and velocity accuracy are all greatly improved.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the invention will be further described, in accompanying drawing:

Fig. 1 be the embodiment of the present invention based on T ²the time difference of/R and the process flow diagram of Doppler shift combined positioning-method;

Fig. 2 be the embodiment of the present invention based on T ²the time difference of/R and the specific implementation method process flow diagram of Doppler shift combined positioning-method;

Fig. 3 be the embodiment of the present invention based on T ²the time difference of/R and the co-located schematic diagram of Doppler shift combined positioning-method;

Fig. 4 be the embodiment of the present invention based on T ²the time difference of/R and the theory diagram of Doppler shift co-located system;

In figure, 401-frequency and distance acquiring unit, the 402-time difference and doppler shift data computing unit.403-co-located unit.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.

As shown in Figure 1, the embodiment of the present invention based on T ²the time difference of/R and Doppler shift combined positioning-method, comprise the following steps:

The shortwave broadcasting radio station of S1, selection two unlike signal frequencies, as cell site, obtains their transmission frequency and coordinate position, and calculates the ground great-circle distance between cell site and receiving station according to coordinate position;

S2, use time difference measurement method according to signal frequency and ground great-circle distance, calculate the time difference data between direct wave and scattering wave and doppler shift data, wherein, direct wave is cell site's signal that receiving station directly receives, and scattering wave is transmit to be irradiated to the signal that airflight target back reflection arrives receiving station;

The time difference data that S3, basis obtain and doppler shift data co-located, calculate position and the flying speed of airbound target.

As shown in Figure 2, in another embodiment of the present invention, the method comprises the following steps:

(1) short-wave signal is received;

Utilize existing shortwave broadcasting radio station as external sort algorithm signal.

(2) shortwave broadcasting radio station is screened

Divide list according to the short-wave all-frequency band radio frequency that International Telecommunications Union (ITU) issues, obtain shortwave broadcasting frequency of radio station, site, cell site, select any two wherein.But cell site can not coexist on a coordinate position with receiving station, two shortwave broadcasting signals adopt AM modulation system, and are different frequency short-wave signal.

(3) ground great-circle distance between transmitting-receiving two station is calculated;

Utilize these shortwave broadcasting radio station cell site longitudes and latitudes, calculate the ground great-circle distance between transmitting-receiving two station.

(4) time difference and Doppler shift information is calculated;

Between known signal frequency and receiving station of cell site in the great-circle distance situation of ground, extract direct-path signal, this direct wave is cell site's signal that receiving station directly receives.Extract scattering wave signal, this signal is that after cell site transmits and is irradiated to air mobile target, reflection arrives the signal of receiving station.Recycling TDOA estimation algorithm obtains continuously secondary time difference information between direct wave and scattering wave, and utilizes Doppler frequency estimation algorithm to obtain continuously secondary Doppler shift information between direct wave and scattering wave.

(5) co-located;

Airbound target position and flying speed is obtained by the time difference and Doppler shift co-located.

As shown in Figure 3, the concrete steps of co-located are:

(5.1) time difference measurement equation is calculated to the Jacobi matrix of target initial state vector;

Hypothetical target initial state vector is X ₀:

X ₀＝[[x ₀y ₀v _xv _y]] ^T

Wherein (x ₀, y ₀) be target initial position, (v _x, v _y) represent that target velocity is at x, the component in y-axis.[] ^trepresent matrix transpose operation.

In the kth time moment, target uniform motion speed is (v _x, v _y), then known target location:

x _k＝x ₀+kΔtv _x；

y _k＝y ₀+kΔtv _y；

Wherein, Δ t represents sampling interval duration.

Time difference measurement equation is:

${\mathrm{\τ}}_{jk}=\frac{1}{c}\[r_{jk}+r_{0k}-R_{trj}\],(k=0,1,2,...,N),(j=1,2)$

Wherein τ _jkrepresent the time difference that jGe cell site kth time obtains, c represents the light velocity, r _jk, r _0k, R _trjrepresent distance, the distance between target and receiving station and the distance between cell site j and receiving station between cell site j and target respectively.

Wherein, first cell site is positioned at (x _t1, y _t1), second cell site is positioned at (x _t2, y _t2), receiving station is positioned at (x _r, y _r).

$r_{jk+i}=\sqrt{({\left(x_k-x_{jT}\right)}^2+{\left(y_k-y_{Tj}\right)}^2)}$

$r_{0k+i}=\sqrt{({\left(x_k-x_R\right)}^2+{\left(y_k-y_R\right)}^2)},(k=0,1,2,...,N)$

$R_{trj}=\sqrt{({\left(x_R-x_{Tj}\right)}^2+{\left(y_R-y_{Tj}\right)}^2)}$

The Jacobi matrix obtaining time difference measurement equation is:

$\frac{\∂{\mathrm{\τ}}_{jk}}{\∂X_0}={\left[\begin{array}{cccc}\frac{\∂{\mathrm{\τ}}_{jk}}{\∂x_0}& \frac{\∂{\mathrm{\τ}}_{jk}}{\∂y_0}& \frac{\∂{\mathrm{\τ}}_{jk}}{\∂v_x}& \frac{\∂{\mathrm{\τ}}_{jk}}{\∂v_y}\end{array}\right]}^T$

Wherein,

$\frac{\∂{\mathrm{\τ}}_{jk}}{\∂x_0}=\frac{1}{c}(\frac{x_k-x_{Tj}}{r_{jk}}+\frac{x_k-x_R}{r_{0k}})$

$\frac{\∂{\mathrm{\τ}}_{jk}}{\∂y_0}=\frac{1}{c}(\frac{y_k-y_{Tj}}{r_{jk}}+\frac{y_k-y_R}{r_{0k}})$

$\frac{\∂{\mathrm{\τ}}_{jk}}{\∂v_x}=\frac{1}{c}(\frac{(x_k-x_{Tj})k\mathrm{\Δ}t}{r_{jk}}+\frac{(x_k-x_R)k\mathrm{\Δ}t}{r_{0k}})$

$\frac{\∂{\mathrm{\τ}}_{jk}}{\∂v_y}=\frac{1}{c}(\frac{(y_k-y_{Tj})k\mathrm{\Δ}t}{r_{jk}}+\frac{(y_k-y_R)k\mathrm{\Δ}t}{r_{0k}})$

(5.2) Doppler shift measurement equation is calculated to the Jacobi matrix of target virgin state vector; Doppler shift measurement equation is:

$f_{jk}=\frac{f_j}{c}\·(-\frac{\left(\right(x_k-x_{Tj})v_x+(y_k-y_{Tj}\left)v_y\right)}{\sqrt{{(x_k-x_{Tj})}^2+{(y_k-y_{Tj})}^2}}-\frac{\left(\right(x_k-x_R)v_x+(y_k-y_R\left)v_y\right)}{\sqrt{{(x_k-x_R)}^2+{(y_k-y_R)}^2}})$

F _jrepresent jGe cell site emission signal frequency.

The Jacobi matrix obtaining Doppler shift measurement equation is:

$\frac{\∂f_{jk}}{\∂X_0}={\left[\begin{array}{cccc}\frac{\∂f_{jk}}{\∂x_0}& \frac{\∂f_{jk}}{\∂y_0}& \frac{\∂f_{jk}}{\∂v_x}& \frac{\∂f_{jk}}{\∂v_y}\end{array}\right]}^T$

Wherein,

$\frac{\∂f_{jk}}{\∂x_0}=\frac{f_j}{c}\left(\begin{array}{c}\frac{(y_k-y_{Tj})\left(\right(y_k-y_{Tj})v_x-(x_k-x_{Tj}\left)v_y\right)}{r_{jk}^3}\\ +\frac{(y_k-y_R)\left(\right(y_k-y_R)v_x-(x_k-x_R\left)v_y\right)}{r_{0k}^3}\end{array}\right)$

$\frac{\∂f_{jk}}{\∂y_0}=\frac{f_j}{c}\left(\begin{array}{c}\frac{(x_k-x_{Tj})\left(\right(x_k-x_{Tj})v_y-(y_k-y_{Tj}\left)v_x\right)}{r_{jk}^3}\\ +\frac{(x_k-x_R)\left(\right(x_k-x_R)v_y-(y_k-y_R\left)v_x\right)}{r_{0k}^3}\end{array}\right)$

$\frac{\∂f_{jk}}{\∂v_x}=\frac{f_j}{c}\left(\begin{array}{c}\frac{r_{jk}^2(x_k-x_{Tj})+(y_k-y_{Tj})k\mathrm{\Δ}t\left(\right(y_k-y_{Tj})v_x-(x_k-x_{Tj})v_y)}{r_{jk}^3}\\ +\frac{r_{0k}^2(x_k-x_R)+(y_k-y_R)k\mathrm{\Δ}t\left(\right(y_k-y_R)v_x-(x_k-x_R)v_y)}{r_{0k}^3}\end{array}\right)$

$\frac{\∂f_{jk}}{\∂v_y}=\frac{f_j}{c}\left(\begin{array}{c}\frac{r_{jk}^2(y_k-y_{Tj})+(x_k-x_{Tj})k\mathrm{\Δ}t\left(\right(x_k-x_{Tj})v_y-(y_k-y_{Tj})v_x)}{r_{jk}^3}\\ +\frac{r_{0k}^2{y}_k+(x_k-x_R)k\mathrm{\Δ}t\left(\right(x_k-x_R)v_y-(y_k-y_R)v_x)}{r_{0k}^3}\end{array}\right)$

(5.3) above-mentioned two result of calculations are combined, obtain Target state estimator equation;

$H_k\left(X_0\right)=\frac{\∂h\left(X\right)}{\∂X_0}=\[\begin{array}{cc}\frac{\∂T_{jk}}{\∂X_0}& \frac{\∂F_{jk}}{\∂X_0}\end{array}\],k=1,2,...N$

By the Jacobi matrix of time difference measurement equation relative target initial state vector, and the Jacobi matrix of Doppler shift measurement equation relative target initial state vector combines.

(5.4) utilize Gauss-Newton batch algorithms, obtain maneuvering target positional information and velocity information.

Target component actual value is made to be X ₀, estimates of parameters is measure equation and can be written as general type:

$Z=h\left(X_0\right)+H(\hat{X}-X_0)+n$

$H_k\left(X_0\right)=\frac{\∂h\left(X\right)}{\∂X_0}=\[\begin{array}{cc}\frac{\∂T_{jk}}{\∂X_0}& \frac{\∂F_{jk}}{\∂X_0}\end{array}\],k=1,2,...N$

Above formula be about linear equation, can process with linear least square, have:

$\hat{X}=X_0+{\left(H^T{S}_k^{-1}H\right)}^{-1}{H}^T{S}_k^{-1}(Z-h(X_0\left)\right)$

Wherein as the initial value of successive approximation method converging on optimal estimation value.

By GN method, can obtain:

${\hat{X}}_{n+1}={\hat{X}}_n-m{\left(H^T{S}_k^{-1}H\right)}^{-1}{H}^T{S}_k^{-1}(Z-h({\hat{X}}_n\left)\right)$

Wherein for latest estimated value, be n-th time iterative estimate value, m is converging factor, generally gets the value being similar to 1.

As shown in Figure 4, the embodiment of the present invention based on T ²the time difference of/R and Doppler shift co-located system, for realize the embodiment of the present invention based on T ²the time difference of/R and Doppler shift combined positioning-method, comprising:

Frequency and distance acquiring unit 401, for selecting the shortwave broadcasting radio station of two unlike signal frequencies as cell site, obtain their transmission frequency and coordinate position, and calculate the ground great-circle distance between cell site and receiving station according to coordinate information;

The time difference and doppler shift data computing unit 402, for using time difference measurement method according to signal frequency and ground great-circle distance, calculate the time difference data between direct wave and scattering wave and doppler shift data, wherein, direct wave is cell site's signal that receiving station directly receives, and scattering wave is transmit to be irradiated to the signal that airflight target back reflection arrives receiving station;

Co-located unit 403, for according to the time difference data obtained and doppler shift data co-located, calculates position and the flying speed of airbound target.

The present invention can not set up on the basis of cell site, utilizes existing shortwave broadcasting radio station as radiation source, and the method for being combined by the time difference and Doppler shift realizes the location to air mobile target.Compared with other passive type object localization methods, the present invention has following characteristics:

(1) the present invention utilizes existing shortwave broadcasting radio station as radiation source, oneself send out do not transmit, therefore have distance, lobe-on-receive, not easily by advantages such as foreign side find;

(2) with general time difference information localization method unlike, what the present invention adopted is time difference information between direct wave and scattering wave, instead of the time difference information between different cell site to receiving station, because this reducing the number required for cell site, be conducive to the quick foundation of shortwave rader system;

(3) the present invention is owing to make use of time difference information and Doppler shift information simultaneously, therefore independently uses the time difference or Doppler shift positioning system relative to other, is all greatly improved in positional precision and velocity accuracy;

(4) owing to employing two metrical informations simultaneously, and You Liangge cell site, be therefore the system of four for state parameter, be in a steady state (SS) always.Therefore, only need in very short system accumulated time, the parameter estimation to target location and velocity information can be realized, be highly suitable for the location to maneuvering target;

(5) owing to present invention employs Gauss-Newton batch algorithms, therefore system accuracy can effectively close to CRLB circle.

Should be understood that, for those of ordinary skills, can be improved according to the above description or convert, and all these improve and convert the protection domain that all should belong to claims of the present invention.

Claims (9)

1. one kind based on T ²the time difference of/R and Doppler shift combined positioning-method, is characterized in that, comprise the following steps:

The shortwave broadcasting radio station of S1, selection two unlike signal frequencies, as cell site, obtains their transmission frequency and coordinate position, and calculates the ground great-circle distance between cell site and receiving station according to coordinate position;

S2, use time difference measurement method according to signal frequency and ground great-circle distance, calculate the time difference data between direct wave and scattering wave and doppler shift data, wherein, direct wave is cell site's signal that receiving station directly receives, and scattering wave is transmit to be irradiated to the signal that airflight target back reflection arrives receiving station;

The time difference data that S3, basis obtain and doppler shift data are combined, and obtain Target state estimator equation, and calculate convergence result by batch algorithms, be position and the flying speed of airbound target.

2. according to claim 1 based on T ²the time difference of/R and Doppler shift combined positioning-method, is characterized in that, the method obtaining shortwave broadcasting radio station transmission frequency and coordinate position in step S1 is:

The short-wave all-frequency band radio frequency issued from International Telecommunications Union (ITU) divides list, and select Liang Ge cell site, cell site can not coexist on a coordinate position with receiving station, and two shortwave broadcasting signals adopt AM modulation system, and are different frequency short-wave signal.

3. according to claim 1 based on T ²the time difference of/R and Doppler shift combined positioning-method, it is characterized in that, step S2 specifically comprises the following steps:

S21, extraction direct-path signal, this direct wave is cell site's signal that receiving station directly receives;

S22, extract scattering wave signal, this signal is that after cell site transmits and is irradiated to air mobile target, reflection arrives the signal of receiving station;

S23, the time difference information utilizing TDOA estimation algorithm to obtain between continuous k direct wave and scattering wave;

S24, the Doppler shift information utilizing Doppler frequency estimation algorithm to obtain between continuous k direct wave and scattering wave.

4. according to claim 1 based on T ²the time difference of/R and Doppler shift combined positioning-method, it is characterized in that, step S3 specifically comprises the following steps:

S31, calculating time difference measurement equation are to the Jacobi matrix of target initial state vector;

S32, calculating Doppler shift measurement equation are to the Jacobi matrix of target initial state vector;

S33, carry out Combined Treatment to the result of calculation of step S31 and step S32, two matrixes being about to obtain carry out combination and obtain Target state estimator equation, and its formula is:

$H_k\left(X_0\right)=\frac{\∂h\left(X\right)}{\∂X_0}=\[\begin{array}{cc}\frac{\∂T_{jk}}{\∂X_0}& \frac{\∂F_{jk}}{\∂X_0}\end{array}\],k=1,2,...N$

Wherein, represent that time difference measurement equation is to the Jacobi matrix of target initial state vector, represent that Doppler shift measurement equation is to the Jacobi matrix of target initial state vector;

S34, utilize batch algorithms to solve it, when algorithm convergence, finally obtain maneuvering target positional information and velocity information.

5. according to claim 4 based on T ²the time difference of/R and Doppler shift combined positioning-method, is characterized in that, in step S31, the computing method of target initial state vector are:

X ₀＝[x ₀y ₀v _xv _y] ^T

Wherein, X ₀for target initial state vector, (x ₀, y ₀) be target initial position, (v _x, v _y) be the component of target velocity in x, y-axis, [] ^tfor operating transpose of a matrix;

In the kth time moment, target uniform motion speed is (v _x, v _y), then known target location:

x _k＝x ₀+kΔtv _x；

y _k＝y ₀+kΔtv _y；

Wherein, Δ t is sampling interval duration.

6. according to claim 5 based on T ²the time difference of/R and Doppler shift combined positioning-method, is characterized in that, in step S31, time difference measurement equation is:

${\mathrm{\τ}}_{jk}=\frac{1}{c}\[r_{jk}+r_{0k}-R_{trj}\],(k=0,1,2,...,N),(j=1,2)$

Wherein, τ _jkrepresent the time difference that jGe cell site kth time obtains, c represents the light velocity, r _jk, r _0k, R _trjrepresent the distance between cell site j and target respectively, the distance between target and receiving station and the distance between cell site j and receiving station;

First cell site is positioned at (x _t1, y _t1), second cell site is positioned at (x _t2, y _t2), receiving station is positioned at (x _r, y _r), and have:

$r_{jk+i}=\sqrt{({(x_k-x_{jT})}^2+{(y_k-y_{Tj})}^2)}$

$r_{0k+i}=\sqrt{({(x_k-x_R)}^2+{(y_k-y_R)}^2)}$

$R_{trj}=\sqrt{({(x_R-x_{Tj})}^2+{(y_R-y_{Tj})}^2)}$

Wherein, k=0,1,2 ..., N.

7. according to claim 4 based on T ²the time difference of/R and Doppler shift combined positioning-method, is characterized in that, in step S32, Doppler shift measurement equation is:

$f_{jk}=\frac{f_j}{c}\·(-\frac{\left(\right(x_k-x_{Tj})v_x+(y_k-y_{Tj}\left)v_y\right)}{\sqrt{{(x_k-x_{Tj})}^2+{(y_k-y_{Tj})}^2}}-\frac{\left(\right(x_k-x_R)v_x+(y_k-y_R\left)v_y\right)}{\sqrt{{(x_k-x_R)}^2+{(y_k-y_R)}^2}})$

F _jrepresent jGe cell site emission signal frequency.

8. according to claim 4 based on T ²the time difference of/R and Doppler shift combined positioning-method, is characterized in that, uses the concrete grammar of batch algorithms to be in step S34:

Target component actual value is made to be X ₀, estimates of parameters is measure equation and can be written as general type:

Z＝h(X)+n

N is noise, by it to X ₀place makes Taylor series expansion, and the once item of only decimation stage Number Sequence, then:

$Z=h\left(X_0\right)+H(\hat{X}-X_0)+n$

$H_k\left(X_0\right)=\frac{\∂h\left(X\right)}{\∂X_0}=\[\begin{array}{cc}\frac{\∂T_{jk}}{\∂X_0}& \frac{\∂F_{jk}}{\∂X_0}\end{array}\],k=1,2,...N$

Above formula be about linear equation, can process with linear least square, then have:

$\hat{X}=X_0+{\left(H^T{S}_k^{-1}H\right)}^{-1}{H}^T{S}_k^{-1}(Z-h(X_0\left)\right)$

Wherein as the initial value of successive approximation method converging on optimal estimation value;

By Gauss-Newton method, can obtain:

${\hat{X}}_{n+1}={\hat{X}}_n-m{\left(H^T{S}_k^{-1}H\right)}^{-1}{H}^T{S}_k^{-1}(Z-h({\hat{X}}_n\left)\right)$

Wherein for latest estimated value, be n-th time iterative estimate value, m is converging factor, gets the value being similar to 1;

When then think that algorithm is restrained, then net result is target position information and velocity information.

9. one kind based on T ²the time difference of/R and Doppler shift co-located system, is characterized in that, comprising:

Frequency and distance acquiring unit, for selecting the shortwave broadcasting radio station of two unlike signal frequencies as cell site, obtain their transmission frequency and coordinate position, and calculate the ground great-circle distance between cell site and receiving station according to coordinate information;

The time difference and doppler shift data computing unit, for using time difference measurement method according to signal frequency and ground great-circle distance, calculate the time difference data between direct wave and scattering wave and doppler shift data, wherein, direct wave is cell site's signal that receiving station directly receives, and scattering wave is transmit to be irradiated to the signal that airflight target back reflection arrives receiving station;

Co-located unit, for according to the time difference data obtained and doppler shift data co-located, calculates position and the flying speed of airbound target.