RU2709607C1 - Method of determining coordinates of a radio-frequency source from an aircraft board using a tri-orthogonal antenna system - Google Patents

Abstract

FIELD: radio engineering and communications.

SUBSTANCE: invention relates to radio engineering and can be used in radio monitoring systems when solving the problem of hidden determination of radio-frequency source (RFS) coordinates under conditions of a priori uncertainty relative to polarization and spatial parameters of radio signals, noise and interference, when restrictions on overall dimensions of direction-finding antenna system are imposed, in particular for determination of coordinates of radio-frequency source from aircraft (AC) board. Method is based on measurement by means of tri-orthogonal frame antenna system of orthogonal components H_x1, H_y1, H_z1 and H_x2, H_y2, H_z2 vectors of magnetic field intensity

and

at different points of AC location space at moments of time t₁ and t₂, determining orientation of vectors

and

in space, constructing auxiliary planes Ω₁ and Ω₂, determination of RFS position lines l₁ and l₂ at the intersection of auxiliary planes with the Earth's surface, calculating the coordinates of the RFS at the intersection of said RFS position lines.

EFFECT: high accuracy of determining coordinates of a radio-frequency source.

1 cl, 8 dwg

Description

The invention relates to radio engineering and can be used in radio monitoring systems when solving the problem of covert determination of the coordinates of radio emission sources (IRI), in particular for determining the coordinates of the IRI from an aircraft (LA).

координат узла межсетевого сопряжения (УМС) и предварительно заданных частот конвертирования

рабочих частот CP₁, СР₂, вычисляют широту ϕ_ПТ и долготу λ _ПТ пользовательского терминала (ПТ).A known method for determining the location of a user terminal using two satellite transponders (CP) [1]. This method consists in the fact that based on measurements of time delays and frequency shifts between transmitted and received test signals of the system, taking into account the known coordinates of the first and second satellite repeaters CP ₁ , CP ₂ , and their velocity vectors

the coordinates of the gateway node (UMC) and the predefined conversion frequencies

operating frequencies CP ₁ , CP ₂ , calculate the latitude ϕ _PT and longitude λ _PT user terminal (PT).

To implement the specified known method, the following steps are performed:

между первым CР₁ и ПТ;determine the distance

between the first CP ₁ and PT;

между вторым СР₂ и ПТ;determine the distance

between the second CP ₂ and PT;

азимут α_пт вектора скорости пользовательского терминала и его высоту h _ПТ относительно земной поверхности;measure modulus

azimuth α _pt of the user terminal velocity vector and its height h _PT relative to the earth's surface;

и

первого и второго узкополосных тестовых сигналов, обусловленные радиальными скоростями ПТ относительно CP₁ и СР₂, для чего предварительно определяют вероятные местоположения ПТ с учетом известных координат CP₁, СР₂ и определенных параметров

и

Doppler frequency shifts are calculated in the UMC

and

the first and second narrow-band test signals due to the radial speeds of the PT relative to CP ₁ and CP ₂ , for which the probable locations of the PT are preliminarily determined taking into account the known coordinates of CP ₁ , CP ₂ and certain parameters

and

перемещения первого CP₁ относительно ПТ, и/или радиальную скорость

перемещения второго СР₂ относительно ПТ, с учетом доплеровских сдвигов частот

и

determine at least one of the parameters: radial velocity

the movement of the first CP ₁ relative to the PT, and / or radial velocity

the movement of the second SR ₂ relative to the PT, taking into account Doppler frequency shifts

and

calculate the latitude ϕ _PT and longitude λ _PT PT.

With this method, high accuracy is provided for determining the coordinates of the user terminal in a wide range of speeds of its movement by determining the frequency shifts of the system signals.

The disadvantages of the analogue are: a long time to determine the coordinates of the PT associated with the need for additional measurements of the module, the azimuth of the velocity vector of the PT and its height relative to the earth's surface; the need for reciprocal transmission of test signals from the PT, whose coordinates must be determined in the UMC through SR.

A known method of determining the coordinates of the IRI using an aircraft [2]. The specified method is that:

choose a 3-dimensional Cartesian coordinate system (DSC) for making measurements and calculations;

place the meter on the aircraft;

move the specified aircraft in space;

receive a radio signal IRI in a given frequency band ΔF;

measure and remember the primary coordinate-informative parameters of the received radio signal, which are used as the amplitude of the electric field (ANEP) created by the IRI at the points of reception;

measure and store secondary parameters (VP) - the coordinates of the location of the aircraft;

repeatedly measure and remember the ANEP sets E _n (where n = 1 ... N) and VP are the coordinates of the aircraft in the 3-dimensional DSC x _n , _n and z _n in the process of moving the aircraft;

calculate the N-1 coefficients of the circles of Apollonia, as the ANEP relations multiplied by the inverse ratios of the aircraft heights at the corresponding measurement points;

form N-1 spherical position surfaces (SPP) of IRI by constructing and subsequent rotation of the Apollonius circles around the axes connecting the corresponding foci;

as the coordinates of the IRI in space, take the coordinates of the intersection point N-1 of these SPP IRI.

In this method, the error in determining the coordinates of the IRI on the plane is compensated by using the SPP IRI formed by the rotation of the Apollonius circles around the axes connecting the corresponding foci.

The disadvantage of the analogue is the long time it takes to determine the coordinates of the IRI, associated with the need to measure N≥5 times the aggregate of AED and VP in the process of moving the aircraft.

Of the known methods, the closest analogue (prototype) of the proposed method in its technical essence is a method for determining the coordinates of a source of radio emissions from an aircraft [3] consisting in that: receive radio signals of the triorthogonal antenna system (TOAS), measure the coordinates of the centers and the orientation angles of the TOAS at different points in time, then the auxiliary Iranian position planes are formed, the Iranian position lines are defined as the intersection lines of each of the auxiliary positional planes IRI with the Earth’s surface and calculate the coordinates of the IRI at the intersection of the lines of position of the IRI.

The disadvantages of the prototype method are the relatively low accuracy of determining the coordinates of the IRI from the aircraft, due to weak mechanical rigidity and resistance to vibration loads TOAC, consisting of antenna elements (AE) in the form of vibrators.

The aim of the invention is to develop a method that provides higher accuracy in determining the coordinates of the IRI under conditions of high vibrational load on the antenna system (AS), a priori uncertainty regarding the polarization and spatial parameters of radio signals, noise and interference, when restrictions are placed on the overall dimensions of the direction-finding speaker.

This goal is achieved by the fact that in the known method of determining the coordinates of the IRI from the aircraft using TOAS, which consists in the fact that they select DSC O ₃ X ₃ Y ₃ Z ₃ for measurements and calculations, place measuring equipment equipped with TOAS on the aircraft , which is moved in space, the coordinates of the TOAC centers О ₁ and О ₂ are measured and the TOAC orientation angles at time t ₁ and t ₂ , additional DSC О ₁ X ₁ Y ₁ Z ₁ and O ₂ X ₂ Y ₂ Z ₂ are selected for production measurements and calculations taking into account the coordinates of TOAC centers and orientation angles and TOAC at time t ₁ and t ₂ , receive an analog radio signal of unknown polarization TOAC from Iran with unknown coordinates at time t ₁ and t ₂ , form a set of analog radio signals depending on the time and number of the TOAC antenna element for which they are received, convert the totality of the received analog radio signals into discrete signals, with the help of which they form the auxiliary planes for the position of the IRI, determine the position lines of the IRI as the intersection lines of each of the auxiliary planes Nia IRI to the surface of the earth and IRI was calculated coordinates in the point of intersection of lines IRI position as TOAC used triply orthogonal loop antenna system (Torazo).

и

принятого аналогового радиосигнала.To form auxiliary planes of the IRI position, Ω ₁ and Ω ₂ , previously at time t ₁ and t _2, the orthogonal components Н _х1 , Н _у1 , H _z1 and Н _х2 , Н _y2 , Н _z2 magnetic field vectors are measured using TORAC

and

received analogue radio signal.

и

в ДСК О₁X₁Y₁Z₁ и O₂X₂Y₂Z₂ соответственно путем векторного сложения ортогональных компонент Н_х1, Н_у1, H_z1 и Н_x2, Н_y2, H_z2.The orientation of the magnetic field vectors is determined

and

in DSC O ₁ X ₁ Y ₁ Z ₁ and O ₂ X ₂ Y ₂ Z _2, respectively, by vector addition of the orthogonal components H _x1 , H _y1 , H _z1 and H _x2 , H _y2 , H _z2 .

и

соответственно и проходили через начала координат О₁ и О₂.The auxiliary planes of the position of the IRI Ω ₁ and Ω _{2 are built} so that they are perpendicular to the vectors

and

respectively, and passed through the origin O ₁ and O ₂ .

The lines of position of the IRI l ₁ and l _{2 are built} at the intersection of the auxiliary planes of the position of the IRI Ω ₁ and Ω ₂ with the Earth's surface. The coordinates of the point of intersection of the Iranian position lines l ₁ and l ₂ are calculated and these coordinates are taken as the coordinates of the Iran.

Thanks to this new set of essential features through the use of TORAS, which has greater mechanical strength and resistance to vibration loads, the objective of the invention is achieved: to increase the accuracy of determining the coordinates of the IRI under conditions of a priori uncertainty regarding the polarization and spatial parameters of radio signals, noise and interference, when dimensional restrictions are imposed dimensions of direction finding speakers.

The claimed invention is illustrated by drawings, which show:

а также векторов

и

в момент времени t₁;in FIG. 1 position of the Poiting vector

as well as vectors

and

at time t ₁ ;

а также векторов

и

в момент времени t₂;in FIG. 2 position of the Poiting vector

as well as vectors

and

at time t ₂ ;

in FIG. 3 TORAS configuration in DSC;

в ДСК OXYZ;in FIG. 4 orthogonal components H _x , N _y , H _z of the magnetic field vector

in DSC OXYZ;

in FIG. 5 time diagrams of the orthogonal components H _x , H _y , H _z taken on AE _x , AE _y , AE _z TORAC, as well as their values H _x1 , H _y1 , H _z1 and H _x2 , H _y2 , H _z2 , measured in time instants t ₁ and t ₂ ;

in FIG. 6 is a graphical representation of the auxiliary plane Ω ₁ in the DSC O ₃ X ₃ Y ₃ Z ₃ ;

in FIG. 7 is a graphical representation of the auxiliary plane Ω ₂ in the DSC O ₃ X ₃ Y ₃ Z ₃ ;

in FIG. 8 is a graphical representation of determining the coordinates of the IRI as the intersection of the lines of position of the IRI l ₁ and l ₂ .

Determining the coordinates of the IRI is an important component of signal monitoring. The advantage of the IRI OMP system is stealth in determining coordinates due to the absence of active radiation. Placing the technical means of the WMD system on aircraft, including on unmanned aircraft, can significantly expand the monitoring zone with the ability to detect and determine the coordinates of the IRI in hard-to-reach areas.

However, the use of aircraft as a platform for the deployment of radio monitoring means leads to a number of problems, the main of which are:

an increase in the level of interference and the associated reduction in the signal-to-noise ratio at the input of the on-board radio receiver;

the limitation of weight and size indicators of the payload on the aircraft, which do not allow placing on it effective antenna systems and multichannel radio receivers;

instability of the aircraft orientation in space, which leads to a sharp increase in direction finding errors and to a decrease in the accuracy of determining the coordinates of the IRI.

Most of the methods for determining the coordinates of an IRI are based on direction finding of radio signals by several meters, or by one measuring instrument moving in space. In this case, the accuracy of direction finding of radio signals of unknown polarization by classical methods oriented to processing an electromagnetic field of a certain polarization gives significant direction finding errors if the polarization characteristics of the direction-finding speaker are not consistent with the polarization of the incident waves. Improving the direction finding accuracy in most cases is achieved by increasing the base of the direction-finding antenna system, that is, by spacing the antenna elements of the direction-finding antenna system in space.

However, it is possible to determine the coordinates of the IRI using a concentrated speaker capable of determining the polarization of the radio signal at the receiving point.

(или электрического

поля в фиксированной точке пространства.The polarization of an electromagnetic wave is its spatio-temporal characteristic and is determined by the type of trajectory described by the end of the magnetic

(or electric

fields at a fixed point in space.

In FIG. 1 shows the IRI 1 and the meter 2 of the parameters of the electromagnetic wave at time t ₁ .

In FIG. 2 shows IRI 1 and meter 3 of electromagnetic wave parameters at time t ₂ .

Он определяет направление и величину плотности потока мощности электромагнитного поля от ИРИ в каждой точке пространства.The propagation of an electromagnetic wave is accompanied by energy transfer. To characterize this phenomenon, the Poiting vector is introduced

It determines the direction and magnitude of the power flux density of the electromagnetic field from the IRI at each point in space.

совпадает с направлением распространения электромагнитной волны и является результатом векторного произведения векторов напряженности электрического

и магнитного

полей, то есть образует вместе с ними правую тройку векторов.Poiting vector

coincides with the direction of propagation of the electromagnetic wave and is the result of a vector product of electric intensity vectors

and magnetic

fields, that is, forms together with them the right triple of vectors.

а также векторов напряженности электрического

и магнитного

полей в разнесенных точках пространства в моменты времени t₁ и t₂ соответственно.In FIG. 1 and FIG. 2 displays the positions of the Poiting vectors

as well as electric tension vectors

and magnetic

fields at separated points of space at time instants t ₁ and t _2, respectively.

или

перпендикулярных направлению распространения электромагнитной волны.In addition, in FIG. 1 and FIG. Figure 2 shows a part of the phase fronts of the wave Ω ' ₁ and Ω' ₂ , defined as the surface of the identical phases of the field vectors

or

perpendicular to the direction of propagation of the electromagnetic wave.

и

в моменты времени t₁ и t₂ возможно определить координаты ИРИ.Comparing the vectors of the magnetic field

and

at time t ₁ and t ₂ it is possible to determine the coordinates of the IRI.

и

в заявленном способе использована ТОРАС, состоящая из трех ортогональных рамочных антенн 4, 5 и 6 (см. фиг. 3), далее - антенных элементов.To measure the orthogonal components of the magnetic field vectors

and

In the claimed method, TORAS was used, consisting of three orthogonal loop antennas 4, 5 and 6 (see Fig. 3), further - antenna elements.

The method uses the Cartesian coordinate system OXYZ, in which the center of coordinates O is aligned with the center of TORAC, the axes OX, OY and OZ are directed perpendicular to the AE 3, 4 and 5, respectively (see Fig. 3).

(см. фиг. 4).The vector sum of the magnetic field strengths Н _х , Н _у and H _z measured on the AER 4, 5 and 6 TORAS, respectively, at an arbitrary moment in time will be the vector of the magnetic field strength

(see Fig. 4).

In FIG. Figure 5 presents an example of time diagrams of the orthogonal components H _x , H _y , H _z , adopted in the general case of an elliptically polarized analog radio signal on AE 4, 5, and 6 TORAS, respectively. At separated points in space at time t ₁ and t ₂ measure and store the values of the components H _x1 , H _y1 , H _z1 and H _x2 , H _y2 , H _z2 using AE 4, 5 and 6 TORAS, respectively.

и

в пространстве и запоминают их.By vector addition of the orthogonal components H _x1 , H _y1 , H _z1 and H _x2 , H _y2 , H _z2 , the orientation of the vectors

and

in space and remember them.

In FIG. 6 and FIG. 7 shows the topocentric DSC O ₃ X ₃ Y ₃ Z ₃ selected for measurements and calculations in which the origin is aligned with the observer's location on the Earth’s surface O ₃ , the O ₃ X ₃ axis is at the intersection of the plane of the local horizon and the observer’s meridian and is directed to south, the axis O ₃ Z _{3 is} directed normal to the plane of the local horizon towards the distance from the center of the Earth O ₃ , the axis O ₃ Y ₃ complements the coordinate system to the right. In the selected DSC O ₃ X ₃ Y ₃ Z _{3 the} surface of the Earth will be a plane Ω ₃ .

проходит через центр ТОРАС совмещенный с началом ДСК O₁X₁Y₁Z₁ (фиг. 6) и описывается уравнением:The plane Ω _{1 is} orthogonal to the magnetic field vector

passes through the center TORAS combined with the beginning of the DSC O ₁ X ₁ Y ₁ Z ₁ (Fig. 6) and is described by the equation:

H _x1 x + H _yl y + H _zl z = 0.

проходит через центр ТОРАС совмещенный с началом ДСК O₂X₂Y₂Z₂ (фиг. 7) и описывается уравнением:The plane Ω _{2 is} orthogonal to the magnetic field vector

passes through the center TORAS combined with the beginning of the DSC O ₂ X ₂ Y ₂ Z ₂ (Fig. 7) and is described by the equation:

H _x2 x + H _y2 y + H _z2 z = 0,

Build a line of position of the IRI l ₁ at the intersection of the planes Ω ₁ and Ω ₃ . Algebraically, such a construction corresponds to the solution of the system to the equation:

Similarly, construct the line of position of the IRI l ₂ at the intersection of the planes Ω ₂ and Ω ₃ . Algebraically, such a construction corresponds to the solution of the system to the equation:

The coordinates of the point of intersection of the Iranian position lines l ₁ and l _{2 are} calculated, solving the system of equations:

The solution to this system will be the coordinates of the point of intersection of the Iranian position lines l ₁ and l ₂ . The resulting coordinates are taken as the coordinates of the IRI.

The implementation of the claimed method is mainly advisable when placing TORAS on a moving object, in particular on an aircraft. In this case, it is necessary to determine the coordinates of the aircraft and the orientation angles of the aircraft with high accuracy.

Simulation of the claimed method showed an increase in the accuracy of determining the coordinates of the IRI compared to the prototype method by 10 ... 15% (depending on the vibration load on the antenna systems), under conditions of a priori uncertainty regarding the polarization and spatial parameters of radio signals, noise and interference, when restrictions are imposed on overall dimensions of the direction-finding antenna system, which indicates the possibility of achieving the specified technical result.

SOURCES OF INFORMATION

1. Volkov RV, Sayapin VN, Sevidov VV A method for determining the location of a user terminal using two satellite transponders. Patent RU No. 2 605 457, publ. 12/20/2016 Bull. Number 35.

2. Agievich S.N., Dvornikov S.V., Zemskov D.S., Sevidov V.V., Fedorenko I.V. A method for determining the coordinates of a radio source using an aircraft. Patent RU No. 2644580, publ. 02/13/2018, Bull.№5.

3. Bogdanovsky S.V., Gaidin A.P., Klishin A.V., Simonov A.N. The method of determining the coordinates of the source of radio emissions from the aircraft Patent RUS No. 2619915, publ. 05/19/2017 Bull. Number 14.

Claims (1)

A method for determining the coordinates of a radio emission source (IRI) from an aircraft using a triorthogonal antenna system (TOAS), which consists in choosing a Cartesian coordinate system (DSC) O ₃ X ₃ Y ₃ Z ₃ for making measurements and calculations, and placing measuring equipment equipped with TOAC, on the aircraft, which is moved in space, measure the coordinates of the TOAC centers O ₁ and O ₂ and the orientation angles of the TOAC at time t ₁ and t ₂ , choose additional DSC O ₁ X ₁ Y ₁ Z ₁ and O ₂ X ₂ Y ₂ Z ₂ for measurement and calculations taking into account the coordinates of the TOAC centers and the TOAC orientation angles at time t ₁ and t ₂ , receive an analog radio signal of unknown polarization TOAC from Iran with unknown coordinates at time t ₁ and t ₂ , form a set of analog radio signals depending on the time and the numbers of the TOAC antenna element, to which they are received, convert the totality of the received analog radio signals into discrete signals, with the help of which they form auxiliary planes for the position of the IRI, determine the position lines of the IRI as intersection SRI each of the reference planes provisions IRI with the surface of the earth and calculate IRI coordinates in the cross point IRI position, characterized in that as TOAC used triply orthogonal loop antenna system (Torazo) and for generating reference planes IRI position Ω ₁ and Ω ₂ , previously, at time instants t ₁ and t _2, the orthogonal components Н _х1 , Н _y1 , H _z1 and Н _x2 , Н _y2 , Н _z2 of magnetic field vectors are measured using TORAC

and

received analog radio signal, determine the orientation of the magnetic field vectors

and

in the DSC, O ₁ X ₁ Y ₁ Z ₁ and O ₂ X ₂ Y ₂ Z _2, respectively, by vector addition of the orthogonal components H _x1 , H _y1 , H _z1 and H _x2 , H _y2 , H _z2 , auxiliary position planes of the IRI Ω ₁ are constructed and Ω ₂ so that they are perpendicular to the vectors

and

respectively, and passed through the origin of coordinates O ₁ and O ₂ , construct lines of position of the IRI

and

at the intersection of the auxiliary planes of the IRI position Ω ₁ and Ω ₂ with the Earth’s surface, the coordinates of the point of intersection of the IRI position lines are calculated

and

and take these coordinates as the coordinates of the IRI.

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