RU2616597C1 - Direction finder of radio-frequency source with wide-angle conical scan - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: wide angle of the conical scan is achieved by using an antenna beam that is expanded only in one plane passing through its axis of rotation, and the direction finder contains an antenna, a generator of reference signals, radio-frequency receiver, frequency evaluation unit, driver of correction component, two deviation signal conditioners and two scaling units coupled in a certain manner.

EFFECT: expanded flare of the conical area of two-plane direction finding of radio-frequency source at a fixed level of estimation error for each of its two angular coordinates.

1 tbl, 14 dwg

Description

The proposed direction finder with wide-angle conical scanning refers to the area of radar and is intended to determine the angular coordinates of a location object that is a source of radio emission (IRI) or reflection of radio waves, simultaneously in two direction finding planes - azimuthal and elevation.

Direction finding devices that determine the angular coordinates of the IRI due to a successive change in the orientation of one antenna beam are widely known. Their main advantage is the simplicity of the technical implementation of a radar receiver of radio emission, which, unlike similar receivers of single-pulse direction finders [1], is single-channel.

Two-plane direction finders are known [2, 3], which extract information on two angular coordinates of the IRI on the basis of four-time sequential switching of the orientation of one narrow antenna beam (“needle” or “pencil” type) in four directions. These four directions have the same latitude of angular displacement relative to the reference or equal signal direction (RSN). (For the direction finders under consideration, RSN means the direction in which the signals are received sequentially for each of the directions of the antenna beam orientation that are spaced apart from each other in time). These four directions are arranged in pairs in the azimuthal and elevation planes, each such pair being symmetrical with respect to the RSN. In each direction-finding plane (azimuthal or elevation), the two directions of orientation of the antenna beam are shifted relative to each other by an angle, which is usually chosen equal to the width of the radiation pattern (MD) of the antenna beam at half power [2, 3]. Thus, in four clock cycles of switching the orientation of the antenna beam, a pair of azimuthal and a pair of elevated spatial reception channels are formed, which are separated by time gating. As a result of pairwise comparison (subtraction) of the amplitudes of the signals of the two azimuthal and two elevated spatial reception channels, estimates of the corresponding angular deviations of the IRI relative to the RSN in azimuth and elevation (or the angular coordinates of the IRI measured relative to the RSN) are formed.

In the well-known conical scanning method [2-8], the successive four-stroke switching of the orientation of one axisymmetric antenna beam is replaced by a continuous change in the direction of its axis. The movement of this axis describes in space a conical surface with a vertex located in the phase center of the antenna, and the axis of such a conical surface coincides with the RSN. In order to independently extract estimates of the azimuth and elevation angle of the IRI, the low-frequency envelope of the received IRI signal is detected relative to two orthogonal reference signals of the conical scan. Implementations of the conical scanning method are presented in many printed publications on radar, for example, in [2-8].

In well-known implementations of the conical scanning method, an axisymmetric pencil-type antenna beam is used. The width of this antenna beam determines the solution of the conical region of space in which the direction finding of the IRI is possible and unambiguous estimates of its two angular coordinates (i.e., the conical region of the direction finding of the IRI). Obviously, the expansion of the solution of such a region can be achieved by increasing the width of the antenna beam, at the same time along two orthogonal planes of its section (due to the axial symmetry of this beam). However, this technique entails a significant increase in the error of direction finding of the IRI, both due to a decrease in the antenna gain and due to a decrease in the slope of the slope of the antenna beam bottom. It follows that the possibility of expanding the conical region of direction finding of the IRI is limited by significant losses in the accuracy of direction finding of the IRI.

By wide-angle conical scanning we mean the movement of an antenna beam over a conical surface, the solution of which significantly exceeds the minimum width of the section of a given beam (in terms of half power).

Known wide-angle scanning, carried out according to a linear law and used in surveillance radar systems [2, 3, 8, 9], for example, in panoramic radar stations. Direction finding methods based on the linear movement of the antenna beam in the same plane are tied to this type of wide-angle scanning. The most common of these are amplitude methods for extracting angular coordinate information from the temporal position of the envelope of the received radar signal, which is modulated by a linearly scanning antenna beam. Technical implementations of direction finding methods for survey radar systems are presented by structures and corresponding algorithms in literature [2, 3, 7-9], where these methods are divided according to the procedures used to estimate the information time parameter. Along with this, the application of phase direction finding methods in survey radar systems is also known, for example, the phase center scanning method [3].

The indicated methods for direction finding of survey radar systems, based on the linear type of wide-angle scanning, have known drawbacks regarding, in particular, the low accuracy of direction finding of IRI, as shown in [3, 9]. In addition, implementations of these methods in the form of structures relate, as a rule, to single-plane direction finding (most often in azimuth).

The closest in most significant coinciding with the claimed direction-finding essential features, according to the authors, is the direction-finder described in [10, p. 252, fig. 9.16].

The main disadvantage of the specified direction finder prototype and known direction finders, which are analogues of the inventive direction finder, is the small width of the solution in the conical region of the direction finding IRI, in which the estimates of its two angular coordinates are unambiguous. The use of the pencil-shaped axisymmetric antenna beam in the known direction finders limits the possibility of expanding the solution of the conical IRI direction finding region due to the need for corresponding expansion of the radiation pattern (moreover, in two planes at the same time), which, as is known, is associated with the following negative circumstances: (KND) antenna [11], therefore, the signal-to-noise ratio (energy indicator); b) a decrease in direction-finding sensitivity [1, 3, 4] (metric indicator). Joint losses in energy and metric indicators lead to a significant increase in the random (noise, fluctuation) error in estimating each of the two angular coordinates of the IRI.

In this regard, the direction finder is of practical interest, based on the structural basis of the prototype direction finder and allows to provide the largest solution width of the conical IR direction finding region for a given level of estimation error for each of its two angular coordinates, i.e. with significantly smaller losses in the accuracy of direction finding IRI compared with the direction finder prototype. For a quantitative description of the technical result of the invention, a measure is taken of the possible expansion of the solution of the conical region of direction finding of the IRI with a fixed standard deviation (RMS) of the estimate of each of the two angular coordinates of the IRI from its true value.

The direction finder prototype (Fig. 1) contains a series-connected reference signal generator (GOS), an antenna (A) and a radio emission receiver (PRI), as well as the first and second deviation signal conditioners (FSO), the first inputs of which are connected to the output of the radio emission receiver, and their second inputs are connected respectively to the second and third outputs of the reference signal generator, while the outputs of the first and second shaper of the deviation signals are the outputs of the direction finder prototype in azimuth and elevation, respectively.

The direction finder prototype is as follows.

The signal from the IRI comes in the form of a power stream, which is converted by the antenna into an electrical signal at its output. The direction of arrival of this power flow, which is the direction to the IRI, is illustrated in FIG. 3 in the measuring Cartesian coordinate system XYZ, where X0Z and Y0Z are the azimuthal and elevation bearing planes, respectively.

From FIG. Figure 3 shows that the spatial position of the IRI is characterized by two angles θ _X and θ _Y between the RSN and the projection directions on the IRI on the plane X0Z and Y0Z, respectively. Along with this, in FIG. Figure 3 also shows the coordinates of the IRI in the measuring spherical coordinate system (associated with the coordinate system XYZ): the angles θ and ϕ are the latitude and longitude of the IRI, respectively. A pair of angles θ _X and θ _Y (or θ and ϕ) will then be considered the angular coordinates of the IRI, measured relative to the RSN.

The direction finder prototype is synchronized by a control signal, which comes from the first GOS output to the antenna input, which is the positioning axis of its beam by the rotation angle in the X0Y plane (by the longitude of the spherical coordinate system - Fig. 3). This control signal determines the continuous rotation of the pencil-shaped antenna beam around the PCH (axis 0Z) with a circular frequency Ω, which causes its axis to move along the conical surface having a solution Θ (Fig. 4).

In addition to this, FIG. 4 illustrates a continuous change in the angle of rotation Ωt of the axis 0x of the Cartesian coordinate system xyz associated with the antenna beam, relative to the axis 0X of the measuring coordinate system XYZ. The rotation is carried out relatively uniform for the two coordinate systems xyz and XYZ of the vertical axis of the RSN, which coincides with the combined axes 0Z and 0z.

To describe the antenna beam bottom in the xyz coordinate system, we use the angles ϑ _x and ϑ _y between the 0z axis and the projections of the spatial direction characterized by these angles on the x0z and y0z planes, respectively, similarly to the angles θ _X and θ _Y in the XYZ coordinate system (Fig. 3).

A typical DN of the cross section of the pencil-shaped antenna beam of type F ₀ (ϑ _x , 0) in the x0z plane is shown in FIG. 5. The x0z plane is the plane in which this antenna beam has an offset relative to the 0z axis. This offset, as can be seen from FIG. 5, depends on the width of the antenna beam of the "pencil" type Δϑ (in terms of half power) and can be taken equal to Δϑ / 2.

The IRI signal from the antenna output is fed to the PXR input, where it is amplified, time-frequency processed, and the low-frequency envelope is extracted, the amplitude of which changes in time synchronously with the movement of the antenna beam. In addition, in PRI, the received signal of the IRI is normalized using automatic gain control (AGC). The AGC inertia is selected for reasons of ensuring undistorted reproduction of the law of amplitude modulation introduced by the displacement of the antenna beam [2, 8]. Moreover, we can assume that the action of AGC is reduced to replacing the current value of the amplitude of the received IRI signal with a constant coefficient k _A in the frequency band, which is much less than the frequency Ω.

When the signal-to-noise ratio, ensuring the normal functioning of the direction finder-prototype, you can not take into account the small shift of the output signal of the PRI, accompanying amplitude detection in conditions of in-house noise [12]. This assumption allows us to describe the output signal of the PRI of the direction finder prototype s ₀ (θ, ϕ, t) as a function of time and spherical coordinates of the IRI θ and ϕ (Fig. 3). The use of spherical coordinates simplifies further exposition, while the MD of a moving pencil-type antenna beam (Fig. 4) is expressed using the following arguments: F ₀ (θ, Ωt-ϕ), and the received IRI signal is equal to s ₀ (θ, ϕ, t) = k _A F ₀ (θ, Ωt-ϕ).

From the PXR output, the signal s _о (θ, ϕ, t) is supplied simultaneously to the first inputs of the first and second FSO, which process along the azimuthal and elevation direction finding planes, respectively. The azimuthal and elevation reference scanning signals u _X (t) = UcosΩt and u _Y (t) = UsinΩt from the second and third GOS outputs, respectively, are received at the second inputs of the first and second FSOs, respectively, where U is the amplitude of the reference scanning signals.

Each FSO performs the function of multiplying two input signals with the subsequent separation of the DC component. Such an operation is equivalent to phase detection implemented by a phase detector [12, 14].

- на выходе первого ФСО для угла θ_X≅θcosϕ в плоскости X0Z,

- на выходе второго ФСО для угла θ_Y≅θsinϕ в плоскости Y0Z, где верхний индекс

указывает на принадлежность данных оценок пеленгатору-прототипу (здесь и далее).As a result of processing carried out in each of the two FSOs, two signals are generated corresponding to estimates of the angular deviations of the IRI from the RSN (two angular coordinates of the IRI):

- at the output of the first FSO for the angle θ _X ≅θcosϕ in the plane X0Z,

- at the output of the second FSO for the angle θ _Y ≅θsinϕ in the plane Y0Z, where the superscript

indicates the belonging of these estimates to the direction finder prototype (hereinafter).

и

воспроизводятся в виде сигналов на выходах первого и второго ФСО, совпадающих с выходами пеленгатора-прототипа соответственно по азимуту и углу места (фиг. 1), и являются результатом работы пеленгатора-прототипа.Grades

and

reproduced in the form of signals at the outputs of the first and second FSO, coinciding with the outputs of the direction finder prototype, respectively, in azimuth and elevation (Fig. 1), and are the result of the direction finder prototype.

The mathematical operations carried out in the first and second FSO during the scanning period T = 2π / Ω of the antenna beam have the corresponding entries:

- амплитудный коэффициент n-й гармоники спектрального разложения [13] сканирующей ДН F₀(θ,Ωt-ϕ) (

- соответственно для первой гармоники), k_S - коэффициент передачи одного ФСО, k_ε=k_Sk_AU - коэффициент пропорциональности для рассматриваемых оценок.Where

is the amplitude coefficient of the nth harmonic of the spectral decomposition [13] of the scanning pattern F ₀ (θ, Ωt-ϕ) (

- respectively, for the first harmonic), k _S is the transmission coefficient of one FSO, k _ε = k _S k _A U is the proportionality coefficient for the considered estimates.

и

пропорциональны амплитуде первой гармоники спектрального разложения принимаемого сигнала ИРИ, при этом остальные гармоники данного разложения отсекаются, что аналогичным образом показано в [2].From (1) it can be seen that the estimates

and

are proportional to the amplitude of the first harmonic of the spectral decomposition of the received IRI signal, while the remaining harmonics of this decomposition are cut off, which is similarly shown in [2].

от угла θ_X при θ_Y=0 (ϕ=0), являющаяся пеленгационной характеристикой (ПХ) пеленгатора-прототипа в плоскости X0Z, определяется зависимостью

(с точностью до постоянного коэффициента). Аналогично, зависимость оценки

от угла θ_Y при θ_X=0 (ϕ=π/2) или ПХ пеленгатора-прототипа в плоскости Y0Z также определяется зависимостью

. Следовательно, две указанные ПХ совпадают между собой ввиду тождественности условий их формирования при коническом сканировании.Rating Dependence

from the angle θ _X at θ _Y = 0 (ϕ = 0), which is the direction-finding characteristic (PX) of the direction finder prototype in the X0Z plane, is determined by the dependence

(accurate to a constant coefficient). Similarly, the dependence of the estimate

the angle θ _Y at θ _X = 0 (ϕ = π / 2) or the PX of the direction finder prototype in the Y0Z plane is also determined by the dependence

. Therefore, the two indicated HRPs coincide due to the identity of the conditions of their formation during conical scanning.

для широты ИРИ

, которая равна

. Зависимость оценки

от угла θ определена для значений θ≥0 и совпадает с правыми ветвями ПХ по плоскостям X0Z и Y0Z, что следует из (1).By virtue of the described properties of HRP, it is convenient to use the estimate in substantiating the technical result of the invention

for the breadth of Iran

which is equal to

. Rating Dependence

angle θ is defined for values of θ≥0 and coincides with the right PX branches along the planes X0Z and Y0Z, which follows from (1).

It was previously indicated that the main functional indicator reflecting the technical result of the invention is the width of the solution of the conical region of the direction finding of the IRI, which is determined by the distance between the minimum and maximum of the HRP. Therefore, in order to compare the inventive direction finder with the direction finder prototype according to the main functional indicator, you can use either one of the centrally symmetric PX (in the X0Z or Y0Z plane), or the corresponding dependence of the IR latitude estimate on the angle θ.

The technical result from the use of the inventive direction finder is to expand the solution of the conical region of the two-plane direction finding IRI with a fixed level of error in the estimation of each of its two angular coordinates.

To achieve the specified technical result in the direction finder of the radio emission source, which contains, as well as the direction finder prototype, series-connected reference signal generator, antenna and radio emission receiver, as well as the first and second deflection signal shapers, the first inputs of which are connected to the output of the radio emission receiver, and their second inputs are connected respectively to the second and third outputs of the reference signal generator, an extension of the antenna beam is introduced in one plane, which passes through its axis in expansion, as well as a series-connected frequency estimation unit and a correction component driver, as well as the first and second scaling units, the first inputs of which are connected respectively to the outputs of the first and second deviation signal conditioners, the first and second inputs of the frequency estimation unit are connected respectively to the output of the radio emission receiver and the fourth output of the reference signal generator, the second inputs of the first and second scaling units are jointly connected to the output of the shaper corrector boiling components, and their outputs are the outputs of the claimed finder.

In the known direction finders using the conical scanning method, there are no signs distinguishing the claimed direction finder from the direction finder prototype. The use of a modified antenna beam in the inventive direction finder together with newly introduced blocks and connections allows providing an expanded (with respect to known direction finders) solution of the conical region of space in which IR direction finding is possible with a fixed level of estimation error for each of its two angular coordinates.

In many practical applications of direction finders using the conical scanning method, the width of the solution of the conical direction finding region of the IRI is significant, in which the estimates of its angular coordinates are unambiguous. In particular, this refers to a situation where the direction finder antenna is rigidly connected to its movable carrier (platform). The spatial evolution of this carrier is accompanied by changes in the orientation of the antenna beam (for example, due to the inconsistency of the yaw and pitch angles of the unmanned aerial vehicle [15]), which cannot always be fully compensated [16, 17].

The invention is aimed at expanding the solution of the conical region of the direction finding of the IRI, and the technical result of the invention is achieved due to the following two features of the inventive direction finder, which distinguish it from the direction finder prototype.

1. The use of wide-angle conical scanning by the “fan” type antenna beam, similar to panoramic panoramic radars [2, 3, 5, 8]. Such an antenna beam has an expanded beam pattern in only one plane passing through the axis of the conical surface of its movement. The result of scanning with this antenna beam is the coverage of a wide conical region of space in which IR direction finding is possible.

2. Introducing new blocks and links into the functional diagram of the direction finder-prototype, providing the extraction of estimates of the angular coordinates of the IRI, taking into account the specifics of the amplitude modulation of the received IRI signal, associated with the use of the "fan" type antenna beam. The specificity of this modulation allows you to combine the direction finding method used in the direction finder prototype with the additional method introduced into the inventive direction finder, consisting of estimating the contact time with the IRI in order to extract information about the angular position of the IRI within the entire wide conical scanning region of the “fan” type antenna beam .

Let us consider each of the two marked points in turn.

During conical scanning, the axis of the antenna beam moves along the conical surface, and the xyz coordinate system associated with this antenna beam rotates around the PCH axis (coinciding with the axes 0z and 0Z) with an angular velocity Ω relative to the measuring coordinate system XYZ, as illustrated in FIG. 4 for the direction finder prototype and FIG. 6 - for the inventive direction finder.

The solution 0 of the conical surface formed by moving the “pencil” type antenna beam in the direction finder prototype (Fig. 4) is determined by the angle between the two directions of the axis of this beam at two points in time that are apart from each other by half the T / 2 scanning period = π / Ω.

The direction H of the "fan" type antenna beam, the movement of which forms a conical surface with an expanded solution Θ (Fig. 6), corresponds to the distant (relative to the RSN) boundary of the flat vertex portion of the beam of the given beam. In this case, the solution Θ is defined as the angle between the direction of H and the opposite direction of the ST, which is shifted in time by T / 2.

The analytical relationships of the solution Θ with the parameters of the pencil and fan type antenna beams can be easily established based on FIG. 5 and 7, where, respectively, the antenna patterns of these antenna beams are shown. When describing the pattern of each antenna beam in the xyz coordinate system, the angles ϑ _x and ϑ _{y are used} between the 0z axis and the projections of the spatial direction characterized by these angles on the x0z and y0z planes, respectively. The width parameters of the antenna beams under consideration are determined by the level of half power: Δϑ _x - in the x0z plane and Δϑ _y - in the y0z plane. In FIG. 5 shows a cross section of the bottom line of the antenna pencil-type beam in the x0z plane, and FIG. 7 - sections of the bottom of the antenna beam of the "fan" type: a) in the x0z plane; b) in a plane that is orthogonal to the x0z plane and has an offset Δϑ _y / 2 along the ϑ _x axis.

. (Данное численное значение принято с целью упрощения изложения, хотя возможны и другие численные значения [2, 18]). Величина Δϑ принимается как базовая ширина антенного луча, которая соответствует заданным размерам антенны, длине волны λ, а также амплитудно-фазовому распределению поля в раскрыве антенны. Например: Δϑ≅59λ/d, град - в случае равномерного синфазного возбуждения круглого раскрыва антенны диаметром d [11].In the case of the pencil-shaped antenna beam used in the direction finder prototype, the equality Δϑ _x = Δϑ _y = Δϑ is valid, and from FIG. 5 it follows that the solution Θ is equal to the width Δϑ at the intersection of the beam F ₀ (ϑ _x , 0) of this antenna beam of the 0z axis at the level

. (This numerical value was taken to simplify the presentation, although other numerical values are possible [2, 18]). The value Δϑ is taken as the base width of the antenna beam, which corresponds to the given dimensions of the antenna, wavelength λ, as well as the amplitude-phase distribution of the field in the aperture of the antenna. For example: Δϑ≅59λ / d, deg - in the case of uniform in-phase excitation of a round aperture of an antenna with a diameter d [11].

Antenna beam "fan" type, the use of which distinguishes the claimed direction finder from the direction finder of the prototype, we will characterize the coefficient a , reflecting the difference in the width parameters of this beam in the planes x0z and y0z in the form: a = Δϑ _x / Δϑ _y .

The “beam” type antenna beam pattern can be realized through a combination of several (at least two) partial patterns with different offsets in the x0z plane, an example of which is shown in FIG. 7, and the dotted line. Moreover, each such partial MD describes a pencil-type antenna beam with one width parameter Δϑ, and as a result of a linear combination of several partial MDs with different displacements only in the x0z plane, it is easy to obtain Δϑ _x = a Δϑ. In the plane orthogonal to the x0z plane, there are no displacements of the considered partial MDs, therefore: Δϑ _y = Δϑ, as illustrated in FIG. 7, b.

Given the considerations and illustration of the cross section of the antenna beam of the "fan" type in the x0z plane (Fig. 7, a) passing through the axis of the conical scanning surface and the direction H (Fig. 6 and 7, a), a solution of this conical surface for the inventive direction finder will be equal

Let us further establish the relationship between the width parameters of the two types of antenna rays under consideration and the error in estimating each of the two angular coordinates of the IRI (the error in direction finding of the IRI). The most important indicator of this error is considered to be its standard deviation (RMS) σ on RSN [6]. This RMS for the conical scanning method, as is known [18], is equal to

where k _σ is the proportionality coefficient for the standard deviation σ, μ is the slope of the antenna beam slope on the RSN in the x0z plane, q is the signal-to-noise power ratio in the reception band.

From FIG. 5 and 7, a shows that in both cases the value of μ is inversely proportional to the width Δϑ = Δϑ _y and can be described by the well-known expression [1, 18]: μ = k _μ / Δϑ, where k _μ is the proportionality coefficient for μ.

The q value can be easily found from the radar range equation [19] for the passive IRI observation mode (single-beam reception): q = k _q D, where the k _q coefficient includes all other parameters included in the radar range equation (IRI signal power flux density, spectral density of noise power, reception band, etc. [7, 19]); D - directional coefficient (KND) of the antenna.

The relationship between the energy parameter of the KND and the parameters of the width of the DN is established on the basis of the asymptotic expression from [11], which is used for practical calculations. Using parameter introduced above and, we write the expression in the form:

where k _D ≅32000 deg ² when calculating angles in deg.

Substituting (4) into the proportionality for the signal-to-noise ratio determined by the equation of the radar range for the passive mode, we have:

Thus, the width of the antenna beam in this context is not only a metric, but also an energy parameter, which is described in a generalized form in [20]. The combined effect of Δϑ and a on the standard deviation σ is easy to describe by substituting (5) in (3) and expressing the slope μ through the width Δλ. Then:

- коэффициент, связывающий СКО погрешности пеленгации ИРИ с параметрами ширины антенного луча.Where

is the coefficient connecting the standard deviation of the error of direction finding of the IRI with the parameters of the width of the antenna beam.

раз. Если считать, что раствор Θ задается через превышение ширины Δϑ в κ раз - в виде Θ=κΔϑ, то соответствующее СКО будет равно:Analyzing together (2) and (6), it can be seen that an increase in the solution Θ by 2 a - 1 times (with a constant width Δϑ) is associated with a loss in the accuracy of direction finding of the IRI, which is expressed in an increase in the standard deviation σ in

time. If we assume that the solution Θ is specified by exceeding the width Δϑ by κ times - in the form Θ = κΔϑ, then the corresponding standard deviation will be equal to:

The described relationship refers only to the claimed direction finder and is determined through the parameter a of the “fan” type antenna beam.

In the case of a direction finder prototype having a pencil-shaped antenna beam with parameters Δϑ _x = Δϑ _y = Δϑ ( a = 1), the desire to increase the solution Θ by κ times is realized solely due to the corresponding increase in the width Δϑ simultaneously in two planes x0z and y0z (due to the axial symmetry of this ray), which leads to: a) a decrease in the directivity factor by κ ² times, respectively, of q; b) a decrease in the steepness of μ by κ times. Both of these circumstances according to (3) entail a significant increase in the standard deviation σ _{0 of the} direction finder prototype, and:

Comparison of cases of “fan” and “pencil” types of antenna beams corresponding to the claimed direction finder and direction finder prototype can be carried out according to (7) and (8), initially setting the permissible loss of accuracy of direction finding of IRI and determining the possible expansion of the solution Θ. The results of such a comparison, showing the possible expansion of the solution Θ for the two types of antenna beams under consideration, with an increase in the standard deviation of the IRI direction finding error with a step of 1 dB, are presented in the table. The last column of this table provides a quantitative expression of the technical result of the invention, determined by the ratio of expansion indices κ in the cases of the inventive direction finder and direction finder prototype.

раз (примерно на 1,8 дБ) в случае заявляемого пеленгатора, тогда как в случае пеленгатора-прототипа - очень значительное увеличение СКО σ₀ в 4 раза (или на 12 дБ, поскольку κ²=4), что ограничивает применимость такого типа антенного луча при изложенных выше требованиях к пеленгации ИРИ.The results of calculations according to (7) and (8) indicate that, for example, the requirement of a twofold expansion of the solution of the conical IRI direction finding region (κ = 2) entails an increase in the standard deviation σ only

times (about 1.8 dB) in the case of the inventive direction finder, while in the case of the direction finder prototype — a very significant increase in standard deviation σ _{0 by} 4 times (or 12 dB, since κ ² = 4), which limits the applicability of this type of antenna beam with the above requirements for direction finding IRI.

Along with the positive effect of using the “fan” type antenna beam, it should be borne in mind that the technical result of the invention, presented in the table, is achieved only when new blocks and connections are introduced into the functional diagram of the direction finder-prototype. The presence of these blocks and connections is determined by the need to form estimates of the two angular coordinates of the IRI (in the azimuthal and elevation planes) within the entire wide conical region of space covered by the “fan” type antenna beam during scanning.

Turning to FIG. 7a, it is easy to see the range of angles ϑ _x , within which the DN of the "fan" type antenna beam is almost constant - it has a flat vertex section. In this range of angles, the conical scanning method used as in the direction finder prototype is supplemented by the method of extracting angular coordinate information about the IRI, taking into account the specifics of the amplitude modulation of the received IRI signal (introduced by the flat vertex portion of the bottom of the antenna beam of the “fan” type).

The noted specificity of amplitude modulation can be readily seen in FIG. 8, which shows the time diagrams of the received IRI signal for three values of the IRI latitude θ: a) θ <Δϑ _y / 2, b) θ = Δϑ _y / 2, c) θ> Δϑ _y / 2.

From FIG. 8c, it can be seen that in a situation where the angle θ goes beyond the limits of the initial inclined section of the considered DN (slope of the beam crossing the RSN), the basic information about the latitude of the IRI θ is contained in the time interval τ - the time of contact with the IRI. Time τ characterizes the duration of a single amplitude response when a “fan” antenna beam passes directions to the IRI (within the same scanning period).

The relationship between the quantities τ and θ will be described based on FIG. 9, where the dotted line shows the cross section of the beam of the “fan” antenna beam in terms of half power in the plane of the angular coordinates ϑ _x and ϑ _y .

от своего максимального значения (т.е. превосходит уровень половинной мощности). Из фиг. 9 видно, что дуга контакта с ИРИ ограничена углом φ=2πτ/Т, где Т=2π/Ω - период сканирования.The bold line in FIG. 9 the arc of contact with IRI is highlighted. This contact occurs when the DN value corresponding to the direction to the IRI exceeds

from its maximum value (i.e. exceeds the half power level). From FIG. Figure 9 shows that the arc of contact with the IRI is limited by the angle φ = 2πτ / T, where T = 2π / Ω is the scanning period.

The angles θ and Δϑ are represented in the plane of the angular coordinates ϑ _x and ϑ _{y by} segments (Fig. 9), which form an isosceles triangle. Moreover, it is believed that the bottom width of the antenna beam of the "fan" type in the plane orthogonal to the x0z plane is equal to the base width: Δϑ _y = Δϑ. Based on the depicted in FIG. 9 of the triangle, we have: θsin (φ / 2) = Δϑ / 2, which, taking into account the equality noted above for the angle φ, leads to the expression:

от своего амплитудного значения. Для гармонического процесса указанное превышение имеет место только на четверти его периода, следовательно:To determine the time τ, we use the well-known [7, 20] method for estimating a non-energy parameter using the equivalent harmonic representation of the information process in which this parameter is contained. Note that in the time interval τ, such an equivalent harmonic process exceeds a level equal to

from its amplitude value. For a harmonic process, the specified excess occurs only in a quarter of its period, therefore:

- частота эквивалентного гармонического процесса [7, 20] (часто: эффективная ширина [12] или среднеквадратическая частота [21] спектральной плотности указанного процесса); коэффициент "4" обусловлен принятым в качестве порогового для контакта с ИРИ уровнем

от максимума ДН;

- коэффициент, учитывающий форму сечения ДН антенного луча «веерного» типа в плоскости y0z (предварительно проведенные численные расчеты по реальным ДН круглой антенны показали, что приближенно можно полагать

).Where

- frequency of the equivalent harmonic process [7, 20] (often: effective width [12] or rms frequency [21] of the spectral density of the indicated process); coefficient "4" is due to the level accepted as a threshold for contact with IRI

from the maximum of NAM;

- coefficient taking into account the shape of the cross section of the bottom of the antenna beam of the “fan” type in the y0z plane (preliminary numerical calculations using real round bottom antennas showed that it can be approximately assumed

)

Substitution of (10) into (9) leads to a simple expression:

- коэффициент пропорциональности между

и θ.Where

- coefficient of proportionality between

and θ.

определяется непосредственно принимаемым сигналом ИРИ s(θ,ϕ,t) согласно известной [7, 20, 21] формуле:Frequency

is determined directly by the received IRI signal s (θ, ϕ, t) according to the well-known formula [7, 20, 21]:

An estimate of the latitude of the IRI θ calculated on the basis of (11) and (12) is used in the inventive direction finder to correct each of the two initial estimates ε _X and ε _{Y of the} angles θ _X and θ _Y, respectively (angular coordinates of the IRI relative to the RSN), which are formed by the method conical scan.

The dependences of the estimates of ε _X and ε _Y on the corresponding angular coordinates θ _x and θ _Y (if the orthogonal angular coordinates are equal to zero) are the initial or uncorrected PX in the X0Z and Y0Z planes. Moreover, both dependences ε _X (θ _X ) and ε _Y (θ _Y ) coincide with each other up to the notation, and their form is shown in FIG. 10, and the dotted line. This coincidence is determined by the identical conditions for the formation of two estimates of ε _X and ε _Y during conical scanning, which is shown in the description of the direction finder prototype.

, а также спады при

, обусловленные соответствующим уменьшением времени τ - фиг. 8, в.In addition, both of these HRs are centrally symmetric: ε _X (-θ _X ) = - ε _X (θ _X ) and ε _Y (-θ _Y ) = - ε _Y (θ _Y ). In this case, the dependence ε _{X (Y)} (θ _{X (Y)} ) has extrema at points with the coordinate

as well as recessions at

due to a corresponding decrease in time τ - FIG. 8, c.

Correction of the estimates of ε _X and ε _Y is introduced in order to expand the operating range at the corresponding angles θ _X and θ _Y , which means the expansion of the solution Θ of the conical region of direction finding of the IRI. In the redistribution of the specified operating range, linearity and uniqueness of conversion of each of the two angular coordinates of the IRI into its estimate is ensured.

In the inventive direction finder, a multiplicative correction is applied, consisting in scaling the initial estimates of ε _X and ε _Y by multiplying each of them by the correcting component g (θ), which has the following properties:

a) symmetry about the 0Z axis in each of the X0Z and Y0Z planes due to the dependence on the argument θ, which is the absolute value of the angular deviation of the IRI from the RSN;

b) a single value within the initial linear sections of two initial unadjusted HR along two direction finding planes;

, компонента g(θ) возрастает таким образом, что достигается не только компенсация спадов зависимостей ε_X(θ_X) и ε_Y(θ_Y) в данной области, но и продолжение (растяжение) линейных участков этих зависимостей при

и

соответственно.c) with increasing θ in the region

, the component g (θ) increases in such a way that not only compensation for the decays of the dependences ε _X (θ _X ) and ε _Y (θ _Y ) in this region is achieved, but also the continuation (extension) of the linear sections of these dependences at

and

respectively.

With sufficient accuracy for practice, the above properties of the component g (θ) are satisfied when it is formed in the form:

- коэффициент, уточняемый исходя из данных ο ДН конкретного антенного луча «веерного» типа. Величина

задает точку сопряжения плоского линейного и квадратичного участков зависимости корректирующей компоненты от угла θ.Where

- coefficient, refined on the basis of the data ο the bottom of a specific antenna beam "fan" type. Value

sets the conjugation point of the flat linear and quadratic sections of the dependence of the correcting component on the angle θ.

(сплошная линия), а зависимость самой этой компоненты от угла

- на фиг. 10, б. Изображенные на графиках фиг. 10 зависимости от угловой координаты θ_X(Y) построены при равенстве нулю соответствующей ортогональной угловой координаты θ_Y(X)=0.The result of applying multiplicative correction based on the component g (θ) is shown in FIG. 10, and in the form of adjusted PX

(solid line), and the dependence of this component itself on the angle

- in FIG. 10 b The graphs of FIG. 10, the dependences on the angular coordinate θ _{X (Y) are} constructed if the corresponding orthogonal angular coordinate θ _{Y (X)} = 0 is equal to zero.

угла θ_X(Y) в виде:Substituting (11) into (13), we obtain the procedure for expanding the conical region of the direction finding of the IRI, implemented in the inventive direction finder. This procedure consists in forming an adjusted estimate

angle θ _{X (Y)} in the form:

.Where

.

принимаемого сигнала ИРИ.It is important to note that the technical result of the invention is achieved only when the procedure (14) and the “fan-shaped” type antenna beam described above are used together in the inventive direction finder. In this case, this antenna beam provides coverage of a wide conical area of direction finding of IRI, and procedure (14) - the expansion of the region of unambiguity of the estimation of each of the angular coordinates θ _X and θ _Y due to additional information about the angle θ contained in the frequency

received signal IRI.

Additionally, we note that the justification of mathematical models for the new blocks and connections introduced into the inventive direction finder refers only to the initially adopted “fan” type antenna beam and describes the necessary conditions for achieving the technical result of the invention, while its quantitative expression is presented in the table above.

In FIG. 1 shows a functional diagram of the prototype, and in FIG. 2 shows a functional diagram of the proposed direction finder, where:

1 - antenna (A),

2 - reference signal generator (GOS),

3 - radio emission receiver (PRI),

4.1 and 4.2 - the first and second shaper signal deviation (FSO), respectively,

5 - block frequency assessment (BOC),

6 - shaper corrective components (FKK),

7.1 and 7.2 - the first and second blocks of scaling (BM), respectively.

In FIG. Figure 3 shows the spatial position of the direction-finding IRI in the measuring coordinate system XYZ and the associated spherical coordinate system.

In FIG. 4 shows a three-dimensional image of the body of the scanning antenna beam of the "pencil" type used in the direction finder prototype, in the XYZ coordinate system and in the xyz coordinate system associated with this beam.

In FIG. Figure 5 shows the cross section of the bottom of the antenna beam of the "pencil" type in the x0z plane passing through the axis of the conical scanning surface and the direction to the IRI.

In FIG. 6 shows a three-dimensional image of the body of the scanning antenna beam of the "fan" type used in the inventive direction finder, in the XYZ coordinate system and in the xyz coordinate system associated with this beam.

In FIG. 7 shows the cross section of the bottom of the antenna beam "fan" type:

a) in the x0z plane passing through the axis of the conical scanning surface and the direction to the IRI;

b) in a plane that is orthogonal to the x0z plane and has an offset Δϑ _y / 2 along the ϑ _x axis.

In FIG. Figure 8 shows the timing diagrams of the received IRI signal at the output of PRI 3 for three different values of the angle θ:

a) θ <Δϑ _y / 2,

b) θ = Δϑ _y / 2,

c) θ> Δϑ _y / 2.

In FIG. Figure 9 shows the cross section of the antenna beam of the "fan" type in the plane of the angular coordinates ϑ _x and ϑ _y .

In FIG. 10 shows the dependencies for the inventive direction finder:

и нескорректированной ε_X(_Y)(θ_X(Y)) оценок угловой координаты θ_X(Y),a) adjusted

and uncorrected ε _X ( _Y ) (θ _{X (Y)} ) estimates of the angular coordinate θ _{X (Y)} ,

.b) corrective components

.

In FIG. 11 shows a block diagram of PRI 3, where:

8 - mixer (CM),

9 - local oscillator (G),

10 - intermediate frequency amplifier (IFA),

11 - block automatic gain control (AGC),

12 - envelope detector (DO).

In FIG. 12 shows a structural diagram of BOCCH 5, where:

13 - derivative calculator (VP),

14.1 and 14.2 - the first and second quadrators (K),

15.1 and 15.2 - the first and second gated integrators (SI),

16 - divider (D).

In FIG. 13 shows the structural diagram of FKK 6, where:

17 - quadrator (K),

18 - multiplier (U),

19 - adder (C),

20 - square root computer (VKK).

In FIG. 14 shows the dependences of the amplitude coefficients of the spectral decomposition of the received IRI signal:

a) for the prototype,

b) for the inventive direction finder,

as well as

c) the right branches of the prototype HRP and the claimed direction finder.

The inventive direction finder of the radio emission source with wide-angle conical scanning (Fig. 2) contains serially connected GOS 2, A 1 and PRI 3, serially connected by BOC 5 and FKK 6, as well as two chains of serially connected FSO 4 and BM 7, while the first inputs of two FSO 4 and the first input of BOC 5 are connected to the output AT 3, the second inputs of the first FSO 4.1, the second FSO 4.2 and BOC 5 are connected respectively to the second, third and fourth outputs of GOS 2, the output of FKK 6 is connected to two second inputs of the first BM 7.1 and second BM 7.2, the outputs of which are you the moves of the inventive direction finder in azimuth and elevation, respectively.

The operation of the inventive direction finder is as follows.

As the initial operating condition of the inventive direction finder, we assume the effect of the IRI signal on the antenna 1 in the form of a power stream, the direction of arrival of which coincides with the direction to the IRI. In antenna 1, this power stream is converted into an electrical signal, which from the output of antenna 1 is fed to input AT 3.

In FIG. 3 shows a geometric model of the spatial position of the IRI in the Cartesian coordinate system XYZ, which is adopted as a measuring coordinate system. The direction to the IRI is characterized by two angles θ _X and θ _Y between the axis 0Z and the projections of this direction on the plane X0Z (azimuthal) and Y0Z (elevation), respectively. The presented geometric model is known and similar to the spatial coordinate model used to control unmanned aerial vehicles [10, p. 131, Fig. 5.21].

Along with this, when describing the operation of the inventive direction finder, we will use the spherical coordinates of the IRI — angles θ and ϕ (Fig. 3) —respectively, the latitude and longitude of the direction to the IRI, which are associated with the XYZ coordinate system. The angles θ _X and θ _Y are expressed in terms of the angles θ and ϕ: tgθ _X = tgθcosϕ and tgθ _Y = tgθsinϕ (Fig. 3) or approximately: θ _X ≅cosϕ and θ _Y ≅θsinϕ, which is acceptable from the standpoint of practice. The pairs of angles (θ _X , θ _Y ) and (θ, ϕ) introduced below will be considered the angular deviations of the direction of the IRI from the RSN or the angular coordinates of the IRI measured relative to the RSN, which coincides with the 0Z axis.

The operation of the inventive direction finder, as well as the direction finder-prototype, is synchronized by the signals generated by GOS 2.

The clock signal that controls the scanning of the antenna beam is transmitted from the first output of the GOS 2 to the input of the antenna 1, which is the input of the positioning of the antenna beam by the angle of rotation in the X0Y plane. Under the influence of this signal, the antenna beam makes a continuous rotational movement around the PCH (axis 0Z) along the conical surface, as shown in FIG. 6.

From this figure it can be seen that, in contrast to the direction finder prototype (Fig. 4), the inventive direction finder has a wider angular region of conical scanning, which is due to the use of the "fan" type antenna beam having an expanded beam in the plane of its displacement relative to the RSN. In this case, the axis of rotation of the antenna beam of the "fan" type passes through the region of the slope of the specified extended DN.

FIG. 6 illustrates the continuous movement of the “fan” type antenna beam with a circular frequency Ω, while at the time t this beam is rotated in the X0Y plane by an angle Ωt. The xyz coordinate system associated with the antenna beam is rotated in a similar way, the 0z axis of which coincides with the RSN (also with the 0Z axis), and the 0x and 0y axes form the angle Ωt with the corresponding axes 0X and 0Y. The xyz coordinate system is introduced to describe the spatial characteristics of the "fan" type antenna beam, and also to visually show its difference from the "pencil" type antenna beam (Fig. 5).

The result of using the “fan” type antenna beam is the formation of a conical surface with an expanded solution Θ (as compared with the direction finder prototype), within which IR direction finding is possible. From FIG. Figure 6 shows that the solution Θ is determined both by the displacement of the “fan” type antenna beam relative to the RSN, and by the length of the flat vertex portion of the DN of this beam. To illustrate this in FIG. Figure 6 shows the direction H corresponding to the point farthest from the RSN of the flat vertex portion of the DN of the "fan" type antenna beam, as well as the opposite direction of the PN (relative to the RSN). When moving the direction H, a conical surface is formed, for which the direction H acts as a generator.

It was previously noted that the use of wide-angle conical scanning is a basic condition for achieving the technical result of the invention. In this regard, we will consider separately the specifics of the “beam” type antenna beam in the xyz coordinate system associated with it. Similarly to the description above for the case of the direction finder prototype, in the xyz coordinate system we will operate with the angles ϑ _x and ϑ _y , which are formed by the 0z axis and the projections of the spatial direction characterized by these angles on the x0z and y0z planes, respectively. The angles ϑ _x and ϑ _y in the xyz coordinate system are similar to the angles θ _X and θ _Y in the XYZ coordinate system (Fig. 3).

In FIG. 7a shows the cross section of the DN of the “fan” type antenna beam in the x0z plane. It is accepted that the “fan” type antenna beam has an increased width Δϑ _x (in terms of half power) only in the x0z plane (Fig. 7a), while in the orthogonal plane the corresponding width Δϑ _y is equal to the base width Δϑ. The cross section of the beam of the considered antenna beam in the indicated orthogonal plane is illustrated in FIG. 7b, while the displacement of this section relative to the 0z axis along the coordinate ϑ _{x is} chosen equal to Δϑ _y / 2, since in the interval from Δϑ _y / 2 to Δϑ _x -Δϑ _y / 2 this section remains constant (within the flat vertex region of this NAM). The base width Δϑ reflects the potential of antenna 1 from the position of IR direction finding and is determined by the dimensions of antenna 1, wavelength λ, and also the amplitude-phase distribution of the field in the aperture of antenna 1 (which was considered earlier).

The extension of the antenna beam in only one plane (x0z) can be realized using one of the known methods for the synthesis of MDs of a given shape [22, 23]. As an example in FIG. 7a, a variant of obtaining MDs with an extended flat vertex portion is shown by combining two partial MDs (shown by a dotted line), which have different displacements along the ϑ _x axis. Moreover, each of the partial MDs refers to the “pencil” type and is characterized by a base width Δϑ = Δϑ _y . Referring to FIG. 7, and the example illustrates the fact that the flat vertex portion of the DN of the "fan" type antenna beam ends at the point Δϑ _x -Δϑ _y / 2, marked by the direction H, therefore, the solution Θ = 2Δϑ _x -Δϑ _y . Note that the decrease in KND, concomitant with the expansion of NAM, is discussed above and is one of the factors that are taken into account when quantifying the technical result of the invention.

Wide-angle conical scanning used in the inventive direction finder causes amplitude modulation of the IRI signal in an extended range of angles θ _x and θ _y , which also includes a flat vertex portion of the "fan" type antenna beam (up to the H direction - see Fig. 7, but).

The IRI signal modulated by this antenna beam is further processed in PRI 3, the implementation of which for the inventive direction finder does not have the specificity that distinguishes it from the well-known standard schemes used in radar [1-5, 24].

As an example in FIG. 11 shows a possible structural diagram of PRI 3, consisting of a series-connected mixer (SM) 8, an intermediate-frequency amplifier (UPCH) 10 and an envelope detector (DO) 12, as well as a local oscillator (G) 9 and an automatic gain control (AGC) 11. The IRI signal is transmitted from input AT 3 to the first (signal) input of SM 8, and the second (reference) input of SM 8 receives a signal from output G 9 to transfer the IRI signal to an intermediate frequency. The output signal of CM 8 is fed to the input of the amplifier 10, in which this signal is amplified and processed in the spectral region. From the output of the UPCH 10, the processed IRI signal is fed to the input of DO 12, where its amplitude detection is carried out. In this case, the inertia of smoothing of the detected IRI signal in DO 12 ensures the selection of a continuous low-frequency envelope of this signal, the amplitude of which changes synchronously with the movement of the antenna beam. The implementation of DO 12 is typical for direction finders with conical scanning and is presented in a number of literature, for example, in [8] or [2] as an extended signal generator. At the second (control) input of the amplifier 10, a gain control signal is supplied from the AGC block 11, which is generated in the AGC 11 on the basis of the output signal UP 12, which is received both at the output of PRI 3 and at the input of the AGC block 11. The AGC block 11, forming on its output gain control signal (normalization) is also typical for direction finders with conical scanning, and methods for its implementation are disclosed in literature, for example, in [1-4, 24].

Considering the inertia of the detection and control processes of amplification (normalization) in the inventive direction finder similar to the direction finder prototype, we assume that the result of the normalization implemented using AGC 11 is the replacement of the slowly changing amplitude factor of the received IRI signal by a constant coefficient k _A. The slowly varying amplitude fluctuations of the received IRI signal or the multiplicative noise acting as a factor of this signal include those whose correlation time is significantly longer than the scanning period T. Therefore, the harmonics of the information amplitude modulation introduced by the moving “fan” type antenna beam do not fall into the normalization frequency band performed using AGC 11 [2, 8]. In addition, we will assume that the normal operating conditions of the inventive direction finder are ensured with such signal-to-noise ratios that make it possible to consider the combination components of amplitude detection of the noise-to-noise type to be negligible [12, 14].

To describe the received IRI signal at the output of PRI 3, which is a function of time and angular coordinates of the IRI, we use the spherical coordinates of the IRI θ and ϕ, which, as shown above, are associated with the angles θ _X and θ _Y. In this case, the temporal law of movement of the “fan” type antenna beam will be taken into account in the argument of its beam pattern F (θ, Ωt-ϕ) and, based on the above considerations, we will describe the received IRI signal at the output AT 3: s (θ, ϕ, t) = k _A F (θ, Ωt-ϕ), which is similar to the case of the direction finder prototype.

Timing diagrams of the signal s (θ, ϕ, t) shown in FIG. 8 illustrate a change in the shape of a given signal depending on the latitude of the IR θ.

, б) первой гармоники частоты сканирования, где s_m - максимальное значение принимаемого сигнала, соответствующее плоскому вершинному участку ДН (фиг. 7, а). Увеличение угла θ в этой ситуации сопровождается ростом глубины амплитудной модуляции и амплитуды первой гармоники частоты сканирования, что аналогично пеленгатору-прототипу. Граничная ситуация максимума первой гармоники частоты сканирования в сигнале s(θ,ϕ,t) наступает при равенстве θ=Δϑ_y/2, что показано на фиг. 8, б.FIG. 8a reflects the situation when θ <Δϑ _y / 2 and graphically shows the presence of only two spectral components in the signal s (θ, ϕ, t): a) a constant component with a level

, b) the first harmonic of the scanning frequency, where s _m is the maximum value of the received signal corresponding to the flat vertex portion of the beam (Fig. 7, a). An increase in the angle θ in this situation is accompanied by an increase in the depth of amplitude modulation and the amplitude of the first harmonic of the scanning frequency, which is similar to the direction finder prototype. The boundary situation of the maximum of the first harmonic of the scanning frequency in the signal s (θ, ϕ, t) occurs when θ = Δϑ _y / 2, as shown in FIG. 8, b.

Unlike the prototype direction finder, the operation of the inventive direction finder continues even with an increase in the angle θ> Δϑ _y / 2, when the higher (starting from the second) harmonics of the scanning frequency begin to play a noticeable role in the signal s (θ, ϕ, t) the signal s (θ, ϕ, t) acquires a pulsed character, as can be seen from FIG. 8, c. In this situation, the main information parameter that allows us to estimate the angular deviation of the IRI from RSN is the contact time with the IRI τ, and the relationship between the latitude of the IRI θ and the time τ has the inverse proportionality described in (9).

This relationship is clearly reflected in FIG. 9 and was previously considered in the description of the essence and method of achieving the technical result of the invention.

Further processing of the signal s (θ, ϕ, t) reproduced at the output of PRI 3 is carried out in three parallel circuits.

. В дальнейшем изложении оценки ε_X и ε_Y считаются исходными или нескорректированными.The first two chains, represented by two FSO 4, are similar to the direction finder prototype and are designed to generate estimates of ε _X and ε _Y that correspond to angles θ _X and θ _Y within a narrow conical region of space, limited by the initial section of the slope of the bottom of the antenna beam "fan-shaped" type when

. In the following, the estimates of ε _X and ε _Y are considered to be original or uncorrected.

The third circuit, consisting of series-connected BOC 5 and FCC 6, forms, on the basis of the signal s (θ, ϕ, t), a synchronous correction component of two estimates ε _X and ε _Y , which provides an extension of the conical direction finding direction of the IRI due to the vertex portion of the antenna beam fan "type.

The received IRI signal from output AT 3 is supplied simultaneously to the first inputs of the first FSO 4.1 and the second FSO 4.2. In this case, the azimuthal and elevation reference scanning signals u _X (t) = UcosΩt and u _Y (t) = UsinΩt from the second and third outputs of GOS 2, where U is the amplitude of the reference scanning signals, are received at the second inputs of FSO 4.1 and FSO 4.2.

In each FSO 4, the mathematical operation of multiplying two signals arriving at its first and second inputs is performed, followed by low-pass filtering of the result of this multiplication. Such processing is typical during phase detection and is implemented on the basis of the well-known two-block structure given, for example, in [14, p. 163, fig. 5.1].

Thus, the signals of the angular deviations of the IRI from the RSN at the outputs of the FSO 4.1 and FSO 4.2 are proportional to the cosines of the phase differences between the signal s (θ, ϕ, t) and the corresponding scanning reference signals u _X (t) and u _Y (t). This ensures the separate formation of two independent estimates of each other ε _X and ε _Y at the outputs of FSO 4.1 and FSO 4.2, respectively:

where k _S is the transmission coefficient of each FSO 4, k _ε = k _S k _A U is the proportionality coefficient for the generated estimates,

is the amplitude coefficient of the spectral decomposition of the received IRI signal with a harmonic component with a frequency nΩ. [13].

In order to estimate the angle θ, which is further used to form the correcting component g (θ), the received IRI signal from the output AT 3 is fed to the first input of the BOC 5, the second input of which is affected by the synchronizing signal from the fourth output of the GOS 2.

An example of a structural diagram of a BOC 5 is disclosed in FIG. 12. This example is similar to the block diagram of the rms frequency spectral density meter given in [21, p. 258, fig. 5.20]. The circuit (Fig. 12) contains two parallel circuits, to the inputs of which the input signal BOC 5 is jointly transmitted. The first circuit consists of a series-connected calculator of the derivative (VP) 13, the first quadrator (K) 14.1 and the first gated integrator (SI) 15.1, and the second circuit is from the second K 14.2 and the second SI 15.2 connected in series. The second inputs of both SI 15 are affected by a synchronizing (gating) signal transmitted from the second input of the BOC 5 to two input data. This gate signal is a sequence of short pulses with a repetition period T and sets the time interval during which the input signals of each of the two SRs are accumulated (integrated). The signals accumulated during the time T from the outputs of the first SR 15.1 and the second SR 15.2 are respectively transmitted to the first and the second inputs of the divider (D) 16, where their ratio is calculated, transmitted from the output of D 16 to the output of BOC 5.

, расчет которой требует дополнительной операции извлечения квадратного корня, удобнее использовать квадрат такой оценки, что представлено, например, на схеме в [21, с. 258, рис. 5.20]. С учетом обоснованного выше способа формирования корректирующей компоненты по (13), требующего возведения частоты

в четвертую степень, оценку данной частоты желательно формировать в виде промежуточной величины w, равной квадрату соответствующей круговой частоты

и вычисляемой согласно [7, с. 120] в виде:It should be noted that instead of directly evaluating the frequency

, the calculation of which requires an additional operation to extract the square root, it is more convenient to use the square of such an estimate, which is presented, for example, in the diagram in [21, p. 258, fig. 5.20]. Taking into account the above justified method of forming the correcting component according to (13), which requires the construction of

to the fourth degree, it is desirable to form an estimate of a given frequency in the form of an intermediate quantity w equal to the square of the corresponding circular frequency

and calculated according to [7, p. 120] in the form:

Using the spectral decomposition of the signal s (θ, ϕ, t) using the amplitude coefficients c _n (θ) described in (16) and performing a sequence of analytical actions with (17), we represent the quantity w as a function of the angle θ:

where the index modulus n takes values from zero to a certain number, which limits the number of harmonics of the spectral decomposition of the received IRI signal. The presence of this limitation proceeds from the possibility of taking into account the higher (starting from the second) harmonics of this expansion for given frequency characteristics of PRI 3.

The generated estimate of the frequency of the equivalent harmonic envelope comes from the output of the BOC 5 to the input of the FCC 6 in the form of the value w (θ), which depends on the angle θ. In FCC 6, a nonlinear transformation of this quantity is carried out, leading to the formation of the correcting component g (θ) in the form:

, коэффициент

- описан в (14).Where

, coefficient

- described in (14).

The implementation of transformation (19) does not present technical difficulties and can be performed on the basis of well-known blocks that perform the corresponding mathematical operations.

As an example in FIG. 13 shows a chain of series-connected blocks that make up the FCC structure 6. This circuit includes: a quadrator (K) 17, a multiplier (Y) 18, an adder (C) 19, and a square root calculator (VKK) 20. Moreover, to the second inputs At 18 and C 19, reference values are given - the coefficient K and unit, respectively.

Considering the passage of the input signal FKK 6 through the described sequence of blocks (Fig. 13), it is easy to see the direct correspondence of the processing to the formula (19). The result of this processing is the correcting component g (θ) reproduced at the output of the FCC 6.

This component from the output of FKK 6 enters in the form of a signal simultaneously to the second inputs of both MB 7. At the same time, the signals of the unadjusted estimates ε _X and ε _Y (15) from the outputs of the first FSO 4.1 and second, respectively, are transmitted to the first inputs of the first BM 7.1 and second BM 7.2 FSO 4.2.

и

, соответствующие углам θ_X и θ_Y в расширенных угловых диапазонах азимута и угла места.In each of BM 7, the operation of multiplying its two input signals is performed, and structurally each of BM 7 consists of one element - a multiplier. As a result of two simultaneously conducted multiplications at the outputs of the first BM 7.1 and the second BM 7.2, estimates are adjusted for the region of large values of the angle θ

and

corresponding to the angles θ _X and θ _Y in the extended angular ranges of azimuth and elevation.

и

представляют собой результат работы заявляемого пеленгатора, поскольку его азимутальный и угломестный выходы совмещены соответственно с выходами первого БМ 7.1 и второго БМ 7.2.Adjusted Grades

and

represent the result of the work of the inventive direction finder, since its azimuthal and elevation outputs are combined with the outputs of the first BM 7.1 and the second BM 7.2.

от угла θ_X(Y) при равенстве нулю ортогональной угловой координаты (θ_Y(_X)=0) представляет собой ПХ заявляемого пеленгатора в плоскости XOZ (Y0Z), иллюстрация которой приведена на фиг. 10, а. Этот рисунок показывает, что данная ПХ образуется как результат умножения зависимости исходной нескорректированной оценки ε_X(Y) от угла θ_X(Y) (или исходной ПХ, изображенной на фиг. 10, а пунктиром, рабочий участок которой ограничен диапазоном от

до

,) и корректирующей компоненты g(θ) - фиг. 10, б. Видно, что при масштабировании (коррекции) исходной оценки ε_X(Y) в областях

достигается значительное расширение рабочего участка ПХ заявляемого пеленгатора и покрытие этим рабочим участком углового диапазона от -Θ/2 до Θ/2.Dependence of the adjusted estimate

from the angle θ _{X (Y)} when the orthogonal angular coordinate (θ _Y ( _X ) = 0) is equal to zero, is the PX of the inventive direction finder in the XOZ (Y0Z) plane, an illustration of which is shown in FIG. 10 a. This figure shows that this PX is formed as a result of multiplying the dependence of the original unadjusted estimate ε _{X (Y)} on the angle θ _{X (Y)} (or the original PX shown in Fig. 10, and the dashed line, the working section of which is limited by the range from

before

,) and the correcting component g (θ) - FIG. 10 b It is seen that when scaling (correcting) the initial estimate ε _{X (Y)} in the regions

Significant expansion of the working phase of the inventive direction finder is achieved and coverage of the angular range from -Θ / 2 to Θ / 2 by this working section is achieved.

на основе (17) и (18). Тогда, оценка

примет следующий вид:The analytical record of the correction (14) can be expanded by revealing the frequency

based on (17) and (18). Then, the estimate

will take the following form:

The last expression reveals the essence of the technical result of the invention from the position of using additional information contained in the higher (starting from the second) harmonics of the spectral decomposition of the received IRI signal. The right-hand side of (20) indicates the use of the entire set of harmonics of the received IRI signal, while in the direction finder prototype only one (first) harmonic from a similar set is used.

для широты ИРИ θ. Эта оценка аналогична оценке

, введенной при описании работы пеленгатора-прототипа (определена на области значений θ≥0), и соответствует правым ветвями ПХ заявляемого пеленгатора по плоскостям X0Z и Y0Z.To illustrate the technical result of the invention, we consider the dependence of the assessment

for latitude IRI θ. This rating is similar to the rating.

introduced when describing the operation of the direction finder prototype (defined on the range of θ≥0), and corresponds to the right PX branches of the inventive direction finder along the X0Z and Y0Z planes.

пеленгатора-прототипа и коэффициентов с_n(θ) заявляемого пеленгатора показаны соответственно на фиг. 14 а и б. Нетрудно видеть, что в случае заявляемого пеленгатора кривые с_n(θ) распространены на более широкий диапазон углов θ и имеют больший удельный вес при n≥2 по сравнению с аналогичными кривыми

пеленгатора-прототипа. Данное обстоятельство отражает тот факт, что антенный луч заявляемого пеленгатора имеет «веерный» тип и охватывает при сканировании более широкую коническую область пространства по сравнению с антенным лучом «карандашного» типа пеленгатора-прототипа.In FIG. 14 shows the difference between the direction finder prototype and the inventive direction finder according to the method of using harmonics of the spectral decomposition of the received IRI signal and taking into account their dependences on the angle θ. The curves of these dependences on the angle θ for the coefficients

direction finder prototype and coefficients with _n (θ) of the inventive direction finder are shown respectively in FIG. 14 a and b. It is easy to see that in the case of the inventive direction finder, the curves with _n (θ) are spread over a wider range of angles θ and have a larger specific gravity at n≥2 compared to similar curves

direction finder prototype. This circumstance reflects the fact that the antenna beam of the inventive direction finder has a "fan" type and covers a wider conical region of space when scanning compared to the antenna beam of the "pencil" type of the direction finder prototype.

при n≥2 для пеленгатора-прототипа (фиг. 14, а, пунктирные кривые) не участвуют в формировании оценок угловых координат ИРИ. Следовательно, в результате обработки принимаемого сигнала ИРИ, проводимой в пеленгаторе-прототипе, зависимость оценки

от угла θ (фиг. 14, в, пунктирная кривая) с точностью до постоянного коэффициента повторяет соответствующую зависимость только одного коэффициента

, т.е. амплитуды только первой гармоники принимаемого сигнала ИРИ.Note that the coefficients

when n≥2 for the direction finder prototype (Fig. 14, a, dashed curves) do not participate in the formation of estimates of the angular coordinates of the IRI. Therefore, as a result of processing the received signal of the IRI, conducted in the direction finder prototype, the dependence of the assessment

the angle θ (Fig. 14, c, dashed curve), up to a constant coefficient, repeats the corresponding dependence of only one coefficient

, i.e. amplitudes of only the first harmonic of the received IRI signal.

In contrast, in the inventive direction finder, the processing of the received IRI signal is carried out according to all its harmonic components, and the higher harmonics, starting from n≥2, have more weight due to the “fan” type of antenna beam (Fig. 14, b). The formation of estimates of the angular coordinates of the IRI in the inventive direction finder is carried out on the basis of all coefficients with _n (θ), the combination of which according to (20) leads to the dependence of the ε estimate extended over the angle θ from a given angle (Fig. 14c, solid curve).

, представленных на фиг. 14, в и характеризующих основной функциональный показатель соответственно заявляемого пеленгатора и пеленгатора-прототипа, наглядно иллюстрирует расширение рабочей области по углу θ (или раствора области пеленгации ИРИ), т.е. достигаемый технический результат изобретения.Comparison of two curves ε (θ) and

shown in FIG. 14c and characterizing the main functional indicator of the inventive direction finder and direction finder prototype, respectively, illustrates the expansion of the working area along the angle θ (or the solution of the direction finding area of the IRI), i.e. technical result of the invention achieved.

Thus, the technical result from the use of the inventive direction finder is to expand the solution of the conical working area of the direction finding IRI with a fixed level of error in the estimation of each of its two angular coordinates.

The implementation of the inventive direction finder does not cause practical difficulties, since the newly introduced blocks are complete functional units based on well-known and widespread radio engineering elements manufactured by the domestic industry.

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Claims (1)

Direction finder of a radio emission source with wide-angle conical scanning, comprising serially connected a reference signal generator, an antenna and a radio emission receiver, as well as a first and second deviation signal generators, the first inputs of which are connected to the output of the radio emission receiver, and their second inputs are connected respectively to the second and third outputs of the generator reference signals, characterized in that the antenna beam is expanded in one plane passing through the axis of its rotation, and also introduced sequentially the connected frequency estimator and the driver of the correcting component, as well as the first and second scaling units, the first inputs of which are connected respectively to the outputs of the first and second drivers of the deviation signals, the first and second inputs of the frequency estimator are connected respectively to the output of the radio receiver and the fourth output of the reference signal generator , the second inputs of the first and second scaling units are jointly connected to the output of the shaper of the correction component, and their outputs are the output ladies of the claimed direction finder.

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