# Phase method for direction finding

FIELD: radio detection and ranging, radio navigation, applicable for determining the angular co-ordinates of the signal radiation source.

SUBSTANCE: the claimed method is realized with the aid of a device having three receiving derails, three receivers, two phase-meters, computer, adder and a recording unit connected in a definite way.

EFFECT: enhanced range of one-valued measurement of angles at a small length of the rough measuring base.

3 dwg

The proposed method relates to the field of radar, radio navigation and can be used for determining the angular coordinates of the source signal.

Known phase methods of direction finding (patents of the Russian Federationâ„–â„–2003131, 2006872, 2010258, 2012010, 2134429, 2155352, 2175770; patents Germany No. 2127087, 2710955; patent of great Britain No. 1395599, 1598325; Kinkelin IE and other Phase method for the determination of coordinates. M: Owls. Radio, 1979; Space radio systems. Edited Shibukawa. M: Owls. radio, 1967, s-138 and others).

Known methods most similar to the present invention is a phase method of direction finding (Space radio systems. Edited Shibukawa. M: Owls. radio, 1967, s-138), which is selected as the base object.

The phase direction finding method generally inherent contradiction between the requirements of accuracy and unambiguity of the reference angle. Indeed, according to the formula

Δϕ=2π·d/λ·Cosβ,

where Δϕ - the phase difference between the signals received by two antennas, separated by distance d (measurement basis);

λ wavelength;

β - the angle of arrival of radio waves relative to the normal to the measuring base

the phase system is the more sensitive to changes in angle β, the larger the relative size of the database d/λ. However, with increasing d/λ decreases C is Uchenie angular coordinates β at which the phase difference Δϕ exceeds the value of 2πi.e. comes the ambiguity of reference.

To eliminate the phase ambiguity of the way the location of the radiation source signal are two classical methods: the use of antennas with a sharp directivity and the use of multiple measurement bases (mnogodelnosti).

The direction finding system with highly directional antennas has a large range and high resolution in the direction. However, they require a search of the source signal before the measurement and automatic tracking in the direction of the antenna beam in the measurement process, as well as deprive phase method of direction finding one of its advantages is the possibility of using non-directional (isotropic) antenna systems.

Mnogodelnosti is usually achieved by using multiple measurement bases. While a smaller base forms a rough, but unambiguous scale reference angle βand large base - accurate but ambiguous scale of reference. When choosing a value basis, as well as the number of bases originate from the following considerations.

The number of zones of ambiguity, i.e. regions where the phase difference Δϕ varies by an amount equal to 2π, is determined by the ratio

n=2 d/λ.

For a single reference, you need to choose n=1, so the. to select the database on the basis of conditions

d<λ/2.

The base object uses mnogozonnoy (multibase) antenna system (figure 1). While receiving antennas 1, 2, 3 and 4 have the classic form of the location. As an example we consider the case of four antennas. Small base d_{1}formed by the antennas 1 and 2, provides a rough unambiguous reference large base of d_{2}formed by the antennas 3 and 4 is the exact ambiguous reference.

However, in some cases with large ranges unambiguous measurement of angles β rough base d_{1}may be so small that it is physically impossible to place two antennas (e.g., d_{1}=1 m diameter antennas D=2 m).

In such cases, the formation of coarse scale indirect method.

There are two measuring unequal base d_{1}and d_{2}(figure 2) and on each of them measured phase shifts Δϕ_{1}and Δϕ_{2}. The measurement of the difference of the difference of phases Δϕ_{p}=Δϕ_{1}-Δϕ_{2}equivalent to measuring the phase shift on the basis of length d_{3}=d_{1}-d_{2}.

Thus, choosing the difference bases d_{3}quite small, it is possible to ensure the formation of the corresponding coarse measurement database.

It should be noted that the total phase shift Δϕ_{∑}=Δϕ_{1}Δ
ϕ_{2}can be used to generate a measurement that is equivalent to the measurement of the phase difference on the basis of the d_{4}which length is equal to the sum of the two original databases

d_{4}=d_{1}+d_{2}.

An object of the invention is to increase the unambiguous range measurement of angles with a small length rough measurement database.

The problem is solved in that phase according to the method of direction finding, based on the reception of signals from the four antennas spaced apart and located on the same line, combine two antennas forming the first antenna to form two unequal measurement bases of the first and second antennas, second and third antenna respectively measure the phase difference between the signals received by the specified antennas, determine the difference and the sum of the measured phase difference form using the difference of difference of phases rough, but unambiguous scale reference angles corresponding to small measurement basis, using the amount of phase difference accurate but ambiguous scale of reference angles corresponding to large measurement database.

The relative locations of the antennas 1, 2, 3 and 4 of the base object shown in figure 1. The relative locations of the antennas 1, 2 and 3 of the proposed method is depicted in figure 2. The structural scheme of the device that implements the proposed method is presented in figure 3.

The device comprises series-connected first antenna 1, the first receiver 4, the first phase meter 7, the second input is via a second receiver 5 is connected to the output of the second antenna 2, myCitadel 9 and the block 11 registration of series-connected third antenna 3, the third receiver 6, the second phase meter 8, a second input connected to the output of the second receiver 5, and the adder 10, a second input connected to the output of the first phase meter 7, and the output connected to the second input unit 11 of the Desk, a second input vicites 9 is connected to the output of the second phase meter 8.The proposed method is implemented as follows.

The received signals are:

U_{1}(t)=υ_{1}·Cos(ω_{c}t+ϕ_{1}),

U_{2}(t)=υ_{2}·Cos(ω_{c}t+ϕ_{2}),

U_{3}(t)=υ_{3}·Cos(ω_{c}t+ϕ_{3}), 0≤t≤T_{c},

where υ_{1}that υ_{2}that υ_{3}that ω_{c}that ϕ_{1}that ϕ_{2}that ϕ_{3}T_{c}- amplitude, carrier frequency, initial phase, and the duration of the signals;

output from the receiving antennas 1, 2, 3 through the receivers 4, 5, 6 are received at the two inputs of the phase meter 7 and 8, respectively. And receiving antennas 1, 2, 3 spaced apart and are located on the same line (figure 2). Antennas 1 and 2 is formed by first measuring the base of the d_{1}and antennas 2 and 3, the second measuring BA is and d_{
2}respectively (d_{1}≠d_{2}). The phase meter 7 and 8 measured phase shifts, respectively:

Δϕ_{1}=ϕ_{1}-ϕ_{2}=2π·d_{1}/λ·Cosβ,

Δϕ_{2}=ϕ_{2}-ϕ_{3}=2π·d_{2}/λ·Cosβ,

where d_{1}d_{2}measuring base formed by the antennas 1, 2 and 2, 3 respectively;

λ wavelength;

β - the angle of arrival of radio waves relative to the normal to the measurement database.

The measured shifts of phases Δϕ_{1}and Δϕ_{2}fed to two input vicites 9 and the adder 10.

The measurement of the difference of the difference of phases

Δϕ_{p}=Δϕ_{1}-Δϕ_{2}

equivalent to measuring the phase shift on the basis of which length

d_{3}=d_{1}-d_{2}.

Thus, choosing the difference bases d_{3}quite small, it is possible to ensure the formation of an appropriate measurement base.

The total phase shift

Δϕ_{Σ}=Δϕ_{1}+Δϕ_{2},

obtained at the output of the adder 10 is used to generate measurements, equivalent to measuring the phase difference on the basis of the d_{4}which length is equal to the sum of the two original databases

d_{4}=d_{1}+d_{2}.

Thus formed between measurement bases is the following nerves is in:

d_{3}/λ<1/2≤d_{4}/λ.

The lowest base d_{3}determining the interval unambiguous measurement direction is determined from the condition

d_{3}=λ/|u_{max}-u_{min}|,

where |u_{max}u_{min}| - interval unambiguous measurement guide cosine.

The largest database of d_{4}determines the accuracy of the measurement directions

d_{4}=SΔϕ·λ/2πSu,

where SΔϕ - error phasemeter,

Su - measurement direction.

When negotiating measurement bases should be condition

u_{from}≥2Su_{g},

i.e. twice the maximum error of measurement areas on a rough basis of d_{3}should not exceed the interval unambiguous measurement of the exact directions on the basis of the d_{4}.

To perform the matching conditions database, you must provide certain ratio between coarse and fine databases

d_{4}/d_{3}·SΔϕ_{p}<π.

Thus, the proposed method is compared with the reference object and other technical solutions for a similar purpose provides increased range unambiguous measure angles with a small length rough measurement base. This is achieved by the formation of coarse scale indirect method. Technical implementation of the proposed method requires less to the number of receiving antennas and receivers. This is especially important when the location of sources of radiation signals in a wide frequency range.

The phase method of direction finding, based on the reception of signals from three antennas, spaced apart and located on the same line, characterized in that form two unequal measuring base d_{1}and d_{2}the first and second antennas, the second and third antennas, respectively, measure the phase difference Δϕ_{1}and Δϕ_{2}between the signals received in the first and second, second and third antennas, respectively, determine the difference Δϕ R=Δϕ_{1}-Δand_{2}and the amount of Δϕ_{Σ}=Δϕ_{1}+Δϕ_{2}the measured phase difference form using the difference of difference of phases ΔϕR. gross, but unambiguous scale reference angles corresponding to the small measuring the basis of the d_{2}using the sum of the difference of phases Δϕ_{Σ}- accurate but ambiguous scale of reference angles corresponding to large measurement database d_{1}while the measurement of the difference of the difference of phases Δϕp is equivalent to the measurement of phase shift measurement basis, the length of which d_{3}=d_{1}-d_{2}the measurement of the total phase shift Δϕ_{Σ}equivalent to measuring the phase difference on the measuring base, the length of which d_{4}=_{
1}+d_{2}subject to the fulfillment of the inequality d_{3}/λ<1/2≤d_{4}/λ and approval of measuring bases, which doubled the maximum measurement error on the basis of the d_{3}should not exceed the interval unambiguous direction measurement on the basis of the d_{4}that is provided by the ratio of d_{4}/d_{3}·SΔϕ≤πwhere SΔϕ - error phasemeter.

**Same patents:**

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SUBSTANCE: the phase direction finder has two antennas, two receiving paths, three phase shifters, two phase detectors, two limiters, three adders, two modulus computation devices, subtracting device, amplifier, comparator, gate circuit and an oscillator.

EFFECT: enhanced accuracy of direction finding and excepted its dependence of the attitude of the object of direction-finding.

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FIELD: the proposed mode and arrangement refer to the field of radio electronics and may be used for definition of position of sources of emitting complex signals.

SUBSTANCE: the phase direction finder realizing the proposed phase mode of direction finding, has receiving aerials, receivers and a supporting generator, an impulse generator, an electronic commutator, a phase changer on 90^{○}, a phase detector and an indicator, a heterodyne, a mixer, an amplifier of an intermediate frequency, multipliers and band filters and a line of delay.

EFFECT: elimination of antagonism between requirements to accuracy of measuring and unique angle reading at phase mode of direction finding of sources of emitting of complex signals.

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FIELD: the invention refers to the field of radio technique and may be used in range-difference systems of definition of the position of the sources of radio emissions.

SUBSTANCE: the mode is based on measuring of two differences of distances Δr_{12} and Δr_{13 }to two pairs of mobile supporting points {O_{1},O_{2}}and {O_{1},O_{3 , }} the coordinates ,j= 1,2,3 supporting points O_{j} in the moment of time of measuring of distances, then the vector of measured values is transformed into the vector of the coordinates of the three points F_{1},F_{2} and M belonging to a hyperbolina: the vector is stored and transmitted along the channels of transmitting information into the center of processing information for using it in quality of initial data at solution a range-difference navigational task; at that the points F_{1} and F_{2 }defines the focuses of the hyperbolina if it is a hyperbola or an ellipse or a focus and its projection on a directrix if it is a parabola and the third point belongs to the hyperbolina in such a manner that the position of its project on the direct F_{1}F_{2 }defines the form of the curve of the second order.

EFFECT: decreases volume of stored and transmitted data.

5 dwg

FIELD: radio electronics, applicable for passive radio monitoring in multi-channel system designed for direction finding of several sources of radio emission simultaneously getting into the reception zone.

SUBSTANCE: expanded functional potentialities by way of direction finding in two planes of several sources of radio emission simultaneously getting into the reception zone.

EFFECT: expanded functional potentialities.

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FIELD: finding coordinates of radio source.

SUBSTANCE: as planes of position of radio source the planes are used, which have line of position of radio source, which has to be crossing of two hyperbolic surfaces pf position corresponding to time-difference measurements. Method is based upon reception of signal of radio source by four aerials, on measurement of three differences in time of reception of radio source signal by aerials, which aerials form measuring bases, upon subsequent processing of results of measurements for calculation of values of parameters of position of radio source and for calculating coordinate of radio source as crossing point of three planes of position. Device for realization of the method has four aerials which aerials form three pairs of measuring bases, which bases are disposed in non-coincident planes, three calculators for calculating parameters of position of radio source, calculator of radio source coordinates made in form of unit for solving system of linear equations and indication unit.

EFFECT: precise measurement of linear coordinates of object.

2 cl, 8 dwg

FIELD: radio detection and ranging, radio navigation, applicable for determining the angular co-ordinates of the signal radiation source.

SUBSTANCE: the claimed method is realized with the aid of a device having three receiving derails, three receivers, two phase-meters, computer, adder and a recording unit connected in a definite way.

EFFECT: enhanced range of one-valued measurement of angles at a small length of the rough measuring base.

3 dwg

FIELD: proposed invention refers to radiolocation and may be used for definition of position and movement of sources of radiation of complex signals.

SUBSTANCE: achieved technical result of invention is increase of trustworthiness of reception of useful signals with a priori known carrier frequency and removal of ambiguity of direction finding by suppression false signals (interference) not interesting for radio control and coming from other directions. At that proposed arrangement has receiving antenna with circle diagram of radiation pattern , receiving antenna with cardioidic diagram of radiation pattern, block for control over diagram of radiation pattern, first and second receiving sets, division block, threshold block, former of control pulse, first and second keys, meter of frequency, memory block, block for comparison of codes, motor and register block.

EFFECT: increases trustworthiness of direction finding.

4 dwg