CN102589549A - Three-station direction-measuring cross-positioning and tracking algorithm in earth coordinate system space - Google Patents

Abstract

The invention discloses an algorithm flow for pure-direction-measuring cross-positioning and tracking in an earth coordinate system space by using three observation stations. By adoption of the algorithm flow, a plurality of movement targets can be subjected to pure-direction-measuring cross-positioning and tracking in the earth coordinate system space by using the three observation stations, and the problems of small area range, low accuracy in positioning and tracking and overlarge calculated quantity of the conventional method can be solved. The algorithm flow is technically characterized in that: (1) the algorithm flow has an idea of positioning the three observation stations, calculating coordinates of the three observation stations, measuring the directions of each target opposite to the three observation stations, determining direction planes where the observation stations and the targets are located, and intersecting three different direction planes for the same target, wherein the coordinate of an intersection point is the position of the target; (2) the algorithm formula derivation process is given; and (3) on the basis of the algorithm idea and a formula, a centralized cross-positioning and tracking algorithm flow and a distributed cross-positioning and tracking algorithm flow are given. The algorithm flow is applicable to quick and accurate positioning and tracking of a plurality of movement targets and has an important practical value for military use and civil use.

Description

Three station direction finding cross bearing track algorithms in the terrestrial coordinate system space

Affiliated technical field

The present invention is a kind of method that in the terrestrial coordinate system space, through three station direction findings intersections multiple mobile object is positioned and follows the tracks of.

Background technology

The extremely attention of Chinese scholars and relevant departments always of passive direction finding cross bearing and tracking technique owing to have advantage such as antijamming capability is strong, good concealment.The application of direction finding location technology is of long duration, and exactly the plane that is approximately in a certain zone, utilizes the method for plane geometry to carry out cross bearing calculating then, and not far when target range, this method was simple and effective when scope of activities was little.But continuous development along with technology; The continuous expansion of the scope of activities of the various land, sea and air vehicles; Movement velocity is more and more faster, and it is more and more obvious that the influence of earth curvature just becomes, and the error that this localization method causes has begun in application, to cause serious problems.

In theory in conversion through terrestrial coordinates and geocentric rectangular coordinate; Add the angle of pitch just can be in geocentric rectangular coordinate be the space localizing objects; Can convert terrestrial coordinates into then, thereby but realize cross bearing at too poor interception angle, two stations and the angle of pitch of can't in rectangular coordinate system, carrying out of the angle of pitch precision of the target that obtains through microwave, infrared radiation.

If research station and target being observed all are positioned at research station and the definite aximuthpiston of observed azimuth in fact; As long as all not parallel mutually or coplane of three aximuthpistons at three research stations and same target being observed place, then three aximuthpistons just have and have only an intersection point.Calculate this intersecting point coordinate with method of geometry and can obtain the target location.

Do not find also that from domestic and international disclosed document using this method carries out the correlative study report that the location is handed over again in simple direction finding.

Summary of the invention

Suppose three research station S on the earth _A(φ _A, λ _A, h _A) or (x _A, y _A, z _A) (being respectively the coordinate in earth coordinates and the space geocentric rectangular coordinate system), S _B(φ _B, λ _B, h _B) or (x _B, y _B, z _B), S _C(φ _C, λ _C, h _C) or (x _C, y _C, z _C), a target T ₁, T ₁Respectively at S _A, S _BAnd S _CPosition angle in sky, the local northeast rectangular coordinate system is α _A1, α _B1And α _C1

Through a S _AThe meridian equation do

$\left\{\begin{array}{c}{x}_A=(a/W+h_A)\cos {\mathrm{\φ}}_A\cos {\mathrm{\λ}}_A\\ y_A=(a/W+h_A)\cos {\mathrm{\φ}}_A\sin {\mathrm{\λ}}_A\\ z_A=[a(1-e^2)/W+h_A]\sin {\mathrm{\φ}}_A\end{array}\right.---\left(1\right)$

Wherein, W=(1-e ²Sin ²φ _A) ^1/2,-pi/2≤φ _A≤pi/2

λ rotates around the z axle in system with the space geocentric rectangular coordinate _AThe angle obtains new coordinate system X ' Y ' Z ', some S _ACoordinate under new coordinate system does

$\left\{\begin{array}{c}{x^{\′}}_A=(a/W+h_A)\cos {\mathrm{\φ}}_A\\ {y^{\′}}_A=0\\ {z^{\′}}_A=[a(1-e^2)/W+h_A]{\sin \mathrm{\φ}}_A\end{array}\right.---\left(2\right)$

Through S _AThe expression formula of this meridian tangential equation on coordinate system X ' Y ' Z ' do

$\left\{\begin{array}{c}\frac{\cos {\mathrm{\φ}}_A}{a/W+h_A}{x}^{\′}+\frac{\sin {\mathrm{\φ}}_A}{a(1-e^2)/W+h_A}{z}^{\′}=1\\ y^{\′}=0\end{array}\right.---\left(3\right)$

The angle of this tangent line and X ' axle does

${\mathrm{\μ}}_A=\mathrm{arctg}[\frac{\cos {\mathrm{\φ}}_A}{\sin {\mathrm{\φ}}_A}\·\frac{a(1-e^2)/W+h_A}{a/W+h_A}]---\left(4\right)$

Get

${\mathrm{\&theta;}}_A=\left\{\begin{array}{c}{\mathrm{\&mu;}}_A-\frac{\mathrm{\&pi;}}{2},\mathrm{if}{\mathrm{\&mu;}}_A>0\\ \frac{\mathrm{\&pi;}}{2}+{\mathrm{\&mu;}}_A,\mathrm{if}{\mathrm{\&mu;}}_A<0\end{array}\right.---\left(5\right)$

Therefore, some S _ASky, the northeast rectangular coordinate system at place can be regarded as by space the earth rectangular coordinate system XYZ elder generation initial point motionless, around Z axle rotation λ _AThe angle is then around Y axle rotation θ _AThe angle moves to a S then _AThe place, the coordinate conversion expression formula of this process does

$\left[\begin{array}{c}x\\ y\\ z\end{array}\right]=\left[\begin{array}{c}{x}_A\\ y_A\\ z_A\end{array}\right]+R_Y\left({\mathrm{\&theta;}}_A\right)R_Z\left({\mathrm{\&lambda;}}_A\right)\left[\begin{array}{c}{x}^{\&prime;}\\ y^{\&prime;}\\ z^{\&prime;}\end{array}\right]=\left[\begin{array}{c}{x}_A\\ y_A\\ z_A\end{array}\right]+\left[\begin{array}{ccc}\cos {\mathrm{\&theta;}}_A\cos {\mathrm{\&lambda;}}_A& -\cos {\mathrm{\&theta;}}_A\sin {\mathrm{\&lambda;}}_A& \sin {\mathrm{\&theta;}}_A\\ \sin {\mathrm{\&lambda;}}_A& \cos {\mathrm{\&lambda;}}_A& 0\\ -{\sin \mathrm{\&theta;}}_A\cos {\mathrm{\&lambda;}}_A& \sin {\mathrm{\&theta;}}_A\sin {\mathrm{\&lambda;}}_A& \cos {\mathrm{\&theta;}}_A\end{array}\right]\left[\begin{array}{c}{x}^{\&prime;}\\ y^{\&prime;}\\ z^{\&prime;}\end{array}\right]---\left(6\right)$

In coordinate system X ' Y ' Z ', target T ₁Just through X ' axle and with plane X ' Z ' angle be α _A1The plane on, note is made plane X ' S _AT ₁, face X ' S might as well make even _AT ₁Last two vectors of conllinear not

$e_{A11}^{\&prime;}=\left[\begin{array}{c}0\\ \sin {\mathrm{\&alpha;}}_{A1}\\ \cos {\mathrm{\&alpha;}}_{A1}\end{array}\right]---\left(7\right)$

$e_{A12}^{\&prime;}=\left[\begin{array}{c}1\\ 0\\ 0\end{array}\right]---\left(8\right)$

According to (6), these two vectors in the expression mode of former rectangular coordinate system XYZ kind do

$e_{A11}=R_Y\left({\mathrm{\&theta;}}_A\right)R_Z\left({\mathrm{\&lambda;}}_A\right)\left[\begin{array}{c}0\\ \sin {\mathrm{\&alpha;}}_{A1}\\ \cos {\mathrm{\&alpha;}}_{A1}\end{array}\right]=\left[\begin{array}{c}-\cos {\mathrm{\&theta;}}_A\sin {\mathrm{\&lambda;}}_A\sin {\mathrm{\&alpha;}}_{A1}+\sin {\mathrm{\&theta;}}_A\cos {\mathrm{\&alpha;}}_{A1}\\ \cos {\mathrm{\&lambda;}}_A\sin {\mathrm{\&alpha;}}_{A1}\\ \sin {\mathrm{\&theta;}}_A\sin {\mathrm{\&lambda;}}_A\sin {\mathrm{\&alpha;}}_{A1}+\cos {\mathrm{\&theta;}}_A\cos {\mathrm{\&alpha;}}_{A1}\end{array}\right]=\left[\begin{array}{c}{e}_{A1x1}\\ e_{A1y1}\\ e_{A1z1}\end{array}\right]---\left(9\right)$

$e_{A12}=R_Y\left({\mathrm{\&theta;}}_A\right)R_Z\left({\mathrm{\&lambda;}}_A\right)\left[\begin{array}{c}1\\ 0\\ 0\end{array}\right]=\left[\begin{array}{c}\cos {\mathrm{\&theta;}}_A\cos {\mathrm{\&lambda;}}_A\\ \sin {\mathrm{\&lambda;}}_A\\ -\sin {\mathrm{\&theta;}}_A\cos {\mathrm{\&lambda;}}_A\end{array}\right]=\left[\begin{array}{c}{e}_{A1x2}\\ e_{A1y2}\\ e_{A1z2}\end{array}\right]---\left(10\right)$

So plane (S _A, e _A11, e _A12) expression formula can be written as

Ax+By+Cz+D＝0 (11)

Here it is research station S _AWith to target T ₁Observed bearing α _A1Determined azimuth plane.

Wherein,

$A=\left|\begin{array}{cc}{Y}_1& Y_2\\ Z_1& Z_2\end{array}\right|=\left|\begin{array}{cc}{e}_{A1y1}& e_{A1y2}\\ e_{A1z1}& e_{A1z2}\end{array}\right|---\left(12\right)$

$B=-\left|\begin{array}{cc}{X}_1& X_2\\ Z_1& Z_2\end{array}\right|=-\left|\begin{array}{cc}{e}_{A1x1}& e_{A1x2}\\ e_{A1z1}& e_{A1z2}\end{array}\right|---\left(13\right)$

$C=\left|\begin{array}{cc}{X}_1& X_2\\ Y_1& Y_2\end{array}\right|=\left|\begin{array}{cc}{e}_{A1x1}& e_{A1x2}\\ e_{A1y1}& e_{A1y2}\end{array}\right|---\left(14\right)$

D＝-(Ax _A+By _A+Cz _A) (15)

In like manner, research station S _BWith to target T ₁Observed bearing α _B1Determined azimuth plane (S _B, e _B11, e _B12) expression formula do

A′x+B′y+C′z+D′＝0 (16)

Research station S _BWith to target T ₁Observed bearing α _B1Determined azimuth plane (S _B, e _B11, e _B12) expression formula do

A″x+B″y+C″z+D″＝0 (17)

Wherein,

$A^{\&prime;}=\left|\begin{array}{cc}{Y}_1& Y_2\\ Z_1& Z_2\end{array}\right|=\left|\begin{array}{cc}{e}_{B1y1}& e_{B1y2}\\ e_{B1z1}& e_{B1z2}\end{array}\right|---\left(18\right)$

$B^{\&prime;}=-\left|\begin{array}{cc}{X}_1& X_2\\ Z_1& Z_2\end{array}\right|=-\left|\begin{array}{cc}{e}_{B1x1}& e_{B1x2}\\ e_{B1z1}& e_{B1z2}\end{array}\right|---\left(19\right)$

$C^{\&prime;}=\left|\begin{array}{cc}{X}_1& X_2\\ Y_1& Y_2\end{array}\right|=\left|\begin{array}{cc}{e}_{B1x1}& e_{B1x2}\\ e_{B1y1}& e_{B1y2}\end{array}\right|---\left(20\right)$

D′＝-(A′x _B+B′y _B+C′z _B) (21)

${\mathrm{\&mu;}}_B=\mathrm{arctg}[\frac{\cos {\mathrm{\&phi;}}_B}{\sin {\mathrm{\&phi;}}_B}\&CenterDot;\frac{a(1-e^2)/W+h_B}{a/w+h_B}]---\left(22\right)$

${\mathrm{\&theta;}}_B=\left\{\begin{array}{c}{\mathrm{\&mu;}}_B-\frac{\mathrm{\&pi;}}{2},\mathrm{if}{\mathrm{\&mu;}}_B>0\\ \frac{\mathrm{\&pi;}}{2}+{\mathrm{\&mu;}}_B,\mathrm{if}{\mathrm{\&mu;}}_B<0\end{array}\right.---\left(23\right)$

$\left[\begin{array}{c}{e}_{B1x1}\\ e_{B1y1}\\ e_{B1z1}\end{array}\right]=R_Y\left({\mathrm{\&theta;}}_B\right)R_Z\left({\mathrm{\&lambda;}}_B\right)\left[\begin{array}{c}0\\ \sin {\mathrm{\&alpha;}}_{B1}\\ \cos {\mathrm{\&alpha;}}_{B1}\end{array}\right]=\left[\begin{array}{c}-\cos {\mathrm{\&theta;}}_B\sin {\mathrm{\&lambda;}}_B\sin {\mathrm{\&alpha;}}_{B1}+\sin {\mathrm{\&theta;}}_B\cos {\mathrm{\&alpha;}}_{B1}\\ \cos {\mathrm{\&lambda;}}_B\sin {\mathrm{\&alpha;}}_{B1}\\ \sin {\mathrm{\&theta;}}_B\sin {\mathrm{\&lambda;}}_B\sin {\mathrm{\&alpha;}}_{B1}+\cos {\mathrm{\&theta;}}_B\cos {\mathrm{\&alpha;}}_{B1}\end{array}\right]---\left(24\right)$

${\left[\begin{array}{c}{e}_{B1x2}\\ e_{B1y2}\\ e_{B1z2}\end{array}\right]}_2=R_Y\left({\mathrm{\&theta;}}_B\right)R_Z\left({\mathrm{\&lambda;}}_B\right)\left[\begin{array}{c}1\\ 0\\ 0\end{array}\right]=\left[\begin{array}{c}\cos {\mathrm{\&theta;}}_B\cos {\mathrm{\&lambda;}}_B\\ \sin {\mathrm{\&lambda;}}_B\\ -\sin {\mathrm{\&theta;}}_B\cos {\mathrm{\&lambda;}}_B\end{array}\right]---\left(25\right)$

$A^{\&prime;\&prime;}=\left|\begin{array}{cc}{e}_{C1y1}& e_{C1y2}\\ e_{C1z1}& e_{C1z2}\end{array}\right|---\left(26\right)$

$B^{\&prime;\&prime;}=-\left|\begin{array}{cc}{e}_{C1x1}& e_{C1x2}\\ e_{C1z1}& e_{C1z2}\end{array}\right|---\left(27\right)$

$C^{\&prime;\&prime;}=\left|\begin{array}{cc}{e}_{C1x1}& e_{C1x2}\\ e_{C1y1}& e_{C1y2}\end{array}\right|---\left(28\right)$

D″＝-(A″x _B+B″y _B+C″z _B) (29)

$\left[\begin{array}{c}{e}_{C1x1}\\ e_{C1y1}\\ e_{C1z1}\end{array}\right]=\left[\begin{array}{c}-\cos {\mathrm{\&theta;}}_C\sin {\mathrm{\&lambda;}}_C\sin {\mathrm{\&alpha;}}_{C1}+\sin {\mathrm{\&theta;}}_C\cos {\mathrm{\&alpha;}}_{C1}\\ \cos {\mathrm{\&lambda;}}_C\sin {\mathrm{\&alpha;}}_{C1}\\ \sin {\mathrm{\&theta;}}_C\sin {\mathrm{\&lambda;}}_C\sin {\mathrm{\&alpha;}}_{C1}+\cos {\mathrm{\&theta;}}_C\cos {\mathrm{\&alpha;}}_{C1}\end{array}\right]---\left(30\right)$

${\left[\begin{array}{c}{e}_{C1x2}\\ e_{C1y2}\\ e_{C1z2}\end{array}\right]}_2=\left[\begin{array}{c}\cos {\mathrm{\&theta;}}_C\cos {\mathrm{\&lambda;}}_C\\ \sin {\mathrm{\&lambda;}}_C\\ -{\sin \mathrm{\&theta;}}_C\cos {\mathrm{\&lambda;}}_C\end{array}\right]---\left(31\right)$

${\mathrm{\&mu;}}_C=\mathrm{arctg}[\frac{\cos {\mathrm{\&phi;}}_C}{\sin {\mathrm{\&phi;}}_C}\&CenterDot;\frac{a(1-e^2)/W+h_C}{a/w+h_C}]---\left(32\right)$

${\mathrm{\&theta;}}_C=\left\{\begin{array}{c}{\mathrm{\&mu;}}_C-\frac{\mathrm{\&pi;}}{2},\mathrm{if}{\mathrm{\&mu;}}_C>0\\ \frac{\mathrm{\&pi;}}{2}+{\mathrm{\&mu;}}_C,\mathrm{if}{\mathrm{\&mu;}}_C<0\end{array}\right.---\left(33\right)$

So target T ₁Coordinate satisfy system of equations

$\left\{\begin{array}{c}\mathrm{Ax}+\mathrm{By}+\mathrm{Cz}+D=0\\ A^{\&prime;}x+B^{\&prime;}y+C^{\&prime;}z+D^{\&prime;}=0\\ A^{\&prime;\&prime;}x+B^{\&prime;\&prime;}y+C^{\&prime;\&prime;}z+D^{\&prime;\&prime;}=0\end{array}\right.---\left(34\right)$

Formula (34) can be written as matrix equation

$\left\{\begin{array}{c}\mathrm{Ax}+\mathrm{By}+\mathrm{Cz}+D=0\\ A^{\&prime;}x+B^{\&prime;}y+C^{\&prime;}z+D^{\&prime;}=0\\ A^{\&prime;\&prime;}x+B^{\&prime;\&prime;}y+C^{\&prime;\&prime;}z+D^{\&prime;\&prime;}=0\end{array}\right.\&DoubleRightArrow;\left[\begin{array}{ccc}A& B& C\\ A^{\&prime;}& B^{\&prime;}& C^{\&prime;}\\ A^{\&prime;\&prime;}& B^{\&prime;\&prime;}& C^{\&prime;\&prime;}\end{array}\right]\left[\begin{array}{c}x\\ y\\ z\end{array}\right]=\left[\begin{array}{c}-D\\ -D^{\&prime;}\\ {-D}^{\&prime;\&prime;}\end{array}\right]---\left(35\right)$

Further be written as

$\left[\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{22}\end{array}\right]\left[\begin{array}{c}{x}_1\\ x_2\\ x_3\end{array}\right]=\left[\begin{array}{c}{b}_1\\ b_2\\ b_3\end{array}\right]\&DoubleRightArrow;\mathrm{Ax}=b---\left(36\right)$

If determinant of coefficient D (36) ≠ 0, then it has unique solution

$x_j=\frac{1}{D}{D}_j=\frac{1}{D}(b_1{A}_{1j}+b_2{A}_{2j}+b_3{A}_{3j}),(j=\mathrm{1,2},3)---\left(37\right)$

A wherein _Ij=(1) ^I+jM _IjBe called (i, j) first a _IjAlgebraic complement, M _IjBe (i, j) first a _IjAfter the capable and j of the i row at place are scratched, the 2 rank determinants that stay.

Obtain target T by (37) ₁Coordinate (x, y z), convert terrestrial coordinate (φ into ₁, λ ₁, h ₁)

${\mathrm{\&lambda;}}_1=\arctan \frac{y_1}{x_1}---\left(38\right)$

$m=\frac{x_1^2+y_1^2}{a^2}---\left(39\right)$

$n=\frac{1-e^2}{a^2}{z}_1^2---\left(40\right)$

$r=\frac{m+n-e^4}{6}---\left(41\right)$

$c=\frac{{\mathrm{mne}}^4}{4}---\left(41\right)$

$A=\frac{\sqrt[3]{(c+r^3)+\sqrt{c(c+2r^3)}}}{r}---\left(43\right)$

$t=r(A+\frac{1}{A}+1)---\left(44\right)$

$q=\sqrt{t^2+{\mathrm{me}}^4}---\left(45\right)$

$p=\frac{e^2(m-t)}{q}---\left(46\right)$

$k=\frac{e^2-p+\sqrt{{(e^2-p)}^2+4(q+t)}}{2},\mathrm{ifk}<e^2\&RightArrow;k=\frac{e^2+p+\sqrt{{(e^2+p)}^2-4(q-t)}}{2}---\left(47\right)$

$N=\sqrt{a^2+\frac{z_1^2{e}^2}{{(k-e^2)}^2}}---\left(48\right)$

${\mathrm{\&phi;}}_1=\arcsin \left(\frac{z_1}{N(k-e^2)}\right)---\left(49\right)$

h ₁＝(k-1)N (50)

Description of drawings

Accompanying drawing 1 algorithm basic thought process flow diagram

S _A, S _BAnd S _CBe three direction finding platforms, T ₁Be measured target, T ₁Respectively at S _A, S _BAnd S _CPosition angle in sky, the local northeast rectangular coordinate system is α _A1, α _B1And α _C1S _AAnd α _A1, S _Bα _B1, S _CAnd α _C1The intersection point of the azimuth plane of confirming respectively is exactly target T ₁The position of point.

The algorithm flow that accompanying drawing 2 centralized cross bearings are followed the tracks of

1. the position of three research stations in measuring between earth-based coordinate system;

2. these three research stations record the relative direction of target respectively;

3. the position of these three research stations and the relative direction that records target thereof are pooled to concentrator in real time with the network message form;

4. respectively with the position of each research station and record each observation station of direction calculating of target and the aximuthpiston at target place;

5. the intersecting point coordinate that is directed against three aximuthpistons of same target is the target location.

The algorithm flow that accompanying drawing 3 distributed cross bearings are followed the tracks of

1. the position of three research stations in measuring between earth-based coordinate system;

2. these three research stations record the relative direction of target respectively;

3. separately the research station according to own position and record this point of direction calculating of target and the aximuthpiston that target belongs to;

4. be pooled to concentrator through each research station and target direction face parameter in real time with the network message form;

5. the intersecting point coordinate that is directed against three aximuthpistons of same target is the target location.

Embodiment

The present invention has designed to utilize through the earth great circle of two research stations, the face of land and has carried out two kinds of algorithm flows that cross bearing is followed the tracks of: the algorithm flow that algorithm flow that centralized cross bearing is followed the tracks of and distributed cross bearing are followed the tracks of.

(1) algorithm flow of centralized cross bearing tracking is shown in accompanying drawing 2:

1. the position of three research stations in measuring between earth-based coordinate system;

2. these three research stations record the relative direction of target respectively;

3. the position of these three research stations and the relative direction that records target thereof are pooled to concentrator in real time with the network message form;

4. respectively with the position of each research station and record each observation station of direction calculating of target and the aximuthpiston at target place;

5. the intersecting point coordinate that is directed against three aximuthpistons of same target is the target location.

(2) algorithm flow of distributed cross bearing tracking is shown in accompanying drawing 3:

1. the position of three research stations in measuring between earth-based coordinate system;

2. these three research stations record the relative direction of target respectively;

3. separately the research station according to own position and record this point of direction calculating of target and the aximuthpiston that target belongs to;

4. be pooled to concentrator through each research station and target direction face parameter in real time with the network message form;

5. the intersecting point coordinate that is directed against three aximuthpistons of same target is the target location.

Claims (4)

1. the present invention has provided and in the terrestrial coordinate system space, has utilized three simple direction findings in research station to carry out algorithm thought and derivation of equation process that cross bearing is followed the tracks of.Two kinds of algorithm flows have been designed: the algorithm flow that algorithm flow that centralized cross bearing is followed the tracks of and distributed cross bearing are followed the tracks of.

2. the general technical characteristic of algorithm thought and derivation of equation process:

The coordinate of three research stations of location Calculation itself; Obtain the orientation of relative three research stations of target respectively through direction finding; Confirm the aximuthpiston at research station and target place, can intersect at a point that this intersecting point coordinate is the target location to three of same target different aximuthpistons.

3. the technical characterictic of the algorithm flow that centralized cross bearing is followed the tracks of:

1. the position of three research stations in measuring between earth-based coordinate system;

2. these three research stations record the relative direction of target respectively;

3. the position of these three research stations and the relative direction that records target thereof are pooled to concentrator in real time with the network message form;

4. respectively with the position of each research station and record each observation station of direction calculating of target and the aximuthpiston at target place;

5. the intersecting point coordinate that is directed against three aximuthpistons of same target is the target location.

4. the technical characterictic of the algorithm flow that distributed cross bearing is followed the tracks of:

1. the position of three research stations in measuring between earth-based coordinate system;

2. these three research stations record the relative direction of target respectively;

3. separately the research station according to own position and record this point of direction calculating of target and the aximuthpiston that target belongs to;

4. be pooled to concentrator through each research station and target direction face parameter in real time with the network message form;

5. the intersecting point coordinate that is directed against three aximuthpistons of same target is the target location.

Images