RU2604652C2 - Local phase difference-range-finding radio navigation system - Google Patents

Abstract

FIELD: radar ranging and radio navigation.

SUBSTANCE: invention relates to radio navigation and can be used in local navigation systems and networks for controlling movement of mobile objects in local navigation areas. Mentioned result is achieved due to, that local phase difference-range-finding radio navigation system comprises two transmitters of high-frequency harmonic signals with common transmitting antenna located on the navigation object, three signal receivers with receiving antennae installed in the reference radio navigation points with known coordinates, three wire communication channels of reference radio navigation points with the central processing station (CPS) and installed in the CPS measuring and computing device having three limiting amplifiers, three frequency dividers, six phase detectors, six analogue-to-digital converters and a navigation object coordinate computer.

EFFECT: increase of system noise-immunity and wider field of space, in range of which unambiguous determination of coordinates of navigation object is possible without reducing accuracy.

1 cl, 4 dwg

Description

The invention relates to radio navigation and can be used in local navigation systems and networks to control the movement of mobile objects in local navigation areas.

A known system for determining the location of a vehicle moving on roads (Road vehicle locating system) [PCT International Application N89 / 12835: G01S 5/02, G08G 1/12 - (UK - application. 17.06.88, publ. 28.12.89)] comprising a signal receiver located at a central station, a navigation device located at a moving object, and a transmitter unit such as a radiotelephone connected to the navigation device.

The receiver is an essential feature of the claimed system.

The reason hindering the achievement in this analogue of the technical result provided by the invention is the relatively low accuracy of determining the coordinates, since the coordinates are determined by the navigation device based on data from beacons that are not accurate enough.

Also known is protected by a patent of the Russian Federation No. 20133785 class. G01S 13/00, 1994 a system for determining the location of moving objects, containing a central control center, at least four receiving points, M transmitters, receiving and transmitting antennas, delay measurement units, receivers.

Transmitters and receivers are essential features in the inventive system.

The reason that impedes the achievement in this analogue of the technical result provided by the invention is the complexity of the system, which is due to the large amount of equipment and the need to use a fairly complex system of single time.

The closest in technical essence to the claimed (prototype) is the reversed differential-range radio navigation system [Kinkulkin I.E., Rubtsov V.D., Fabrik M.A. Phase method for determining coordinates. - M .: Soviet Radio, 1979, p. 97-100].

This system contains four transmitters of high-frequency harmonic signals and at least five receivers of these signals. One of the transmitters is installed on a moving object of navigation, the second - on a fixed object, the rest of the transmitters and receivers are installed at reference navigation points with known coordinates.

Transmitters of high-frequency harmonic signals and their receivers are essential features in the inventive system.

The reason that impedes the technical result provided by the invention in the prototype system is the fact that the coordinates of the stationary transmitter are always determined with a certain error, which leads to a decrease in the accuracy of measuring the coordinates of the navigation object.

Another reason that impedes the achievement of the technical result provided by the invention in the prototype system is the need for continuous signal emission by a fixed transmitter. This worsens the conditions of electromagnetic compatibility of the system equipment. There is a need to receive and transmit two signals with close frequencies, which worsens the conditions for ensuring the information security of the system equipment and facilitates the possibility of suppressing its work by a potential attacker. These circumstances significantly reduce the noise immunity of the system.

The third reason that impedes the achievement of the technical result provided by the invention in the prototype system is the small size of the space region within which it is possible to uniquely determine the coordinates of the navigation object with acceptable accuracy. The dimensions of this region of space in the prototype system are limited by the zone in which the distances between the navigation object and each of the reference radio navigation points should differ from each other by no more than half the wavelength of the frequency signal equal to the frequency difference of the signals emitted by the navigation object and the transmitter installed in fixed point.

The technical problem to which the invention is directed is to increase the noise immunity of the system and expand the area of space within which it is possible to uniquely determine the coordinates of the navigation object without compromising accuracy.

To achieve the specified technical result in a known system for measuring the coordinates of a navigation object, comprising a first transmitter of a high-frequency harmonic signal mounted on a navigation object, a second transmitter of a high-frequency harmonic signal, different in frequency from the first by the value of the beat frequency, and three receivers of these signals with antennas, installed in the reference radio navigation points with known coordinates, the second transmitter is installed, like the first, on the navigation object, while the transmitter ba are connected to a common transmitting antenna, three channels of wired communication of reference radio navigation points with a central signal processing center and a measuring and computing device located in a central signal processing station containing three amplifier limiters, three frequency dividers, six phase detectors, are additionally introduced into the system six analog-to-digital converters and a coordinates calculator of the navigation object, while the outputs of the first, second and third receivers through wired communication channels connected to the inputs of the respective limiter amplifiers, the outputs of which are connected respectively to the inputs of the first, second and third frequency dividers and simultaneously with the first inputs of the first, second and third phase detectors, the outputs of the first, second and third frequency dividers are connected respectively to the first inputs of the fourth, fifth and the sixth phase detector, wherein the second input of the second phase detector is connected to the output of the first amplifier-limiter, the second input of the third phase detector is connected to during the second limiter amplifier, the second input of the first phase detector is connected to the output of the third limiter amplifier, the second input of the fourth phase detector is connected to the output of the third frequency divider, the second input of the fifth phase detector is connected to the output of the first frequency divider, the second input of the sixth phase detector is connected to the output of the second frequency divider, and the outputs of all phase detectors through analog-to-digital converters are connected to the corresponding inputs of the calculator of coordinates of the navigation object.

The invention is illustrated in the drawing, which shows:

- in FIG. 1 is a structural diagram of the proposed system;

- in FIG. 2 is a block diagram of a receiver;

- in FIG. 3 - the relative position of the navigation object, reference radio navigation points with receivers and the central processing point (CPO);

- in FIG. 4 - zone of unambiguous determination of the coordinates of the navigation object.

The system for measuring the coordinates of the navigation object contains two high-frequency harmonic signals located at the navigation object 1.1 and 1.2 with a common transmitting antenna 2, three receivers 3.1, 3.2 and 3.3 of these signals with receiving antennas 4.1, 4.2 and 4.3, installed in reference radio navigation points with known coordinates, three channels of wired communication 5.1, 5.2 and 5.3 of reference radio navigation points with a DSP and a measuring and computing device installed in the DPC containing three limiting amplifiers 6.1, 6.2 and 6.3, three frequency dividers 7.1, 7.2 and 7.3, six phase detectors 8.1, 8.2 ... 8.6, six analog-to-digital converters 9.1, 9.2 ... 9.6 and 10 computer navigation coordinates of the object.

Each of the receivers 3.1, 3.2 and 3.3 with antennas 4.1, 4.2 and 4.3 contains a series-connected dual-frequency amplifier 11 and a beat frequency generator, consisting of a series-connected balanced modulator 12, both inputs of which are connected to the output of a dual-frequency amplifier 11, a narrow-band filter 13, and a resonant amplifier 14 tuned to the beat frequency (FIG. 2).

The outputs of the receivers 3.1,3.2 and 3.3 through the channels 5.1, 5.2 and 5.3 of the wire connection are connected respectively to the inputs of the amplifier-limiters 6.1, 6.2 and 6.3. The output of the limiting amplifier 6.1 is connected to the input of the frequency divider 7.1, as well as to the first input of the phase detector 8.1 and the second input of the phase detector 8.3, the output of the limiting amplifier 6.2 is connected to the input of the frequency divider 7.2, as well as the first input of the phase detector 8.3 and the second input phase detector 8.5, the output of the amplifier-limiter 6.3 is connected to the input of the frequency divider 7.3, as well as to the first input of the phase detector 8.5 and the second input of the phase detector 8.1, the output of the frequency divider 7.1 is connected to the first input of the phase detector 8.2 and the second the input of the phase detector 8.4, the output of the frequency divider 7.2 is connected to the first input of the phase detector 8.4 and the second input of the phase detector 8.6, the output of the frequency divider 7.3 is connected to the first input of the phase detector 8.6 and the second input of the phase detector 8.2. The outputs of all phase detectors 8.1,8.2 ... 8.6 through analog-to-digital converters 9.1,9.2 ... 9.6 are connected to the corresponding inputs of the transmitter 10 coordinates of the navigation object.

The operation of the system is illustrated in FIG. 3, which shows a mobile navigation object (MO) with transmitters 1.1 and 1.2 and a common transmitting antenna 2, the reference radio navigation points ORT1, ORT2 and ORTZ with receivers 3.1, 3.2 and 3.3 and receiving antennas 4.1, 4.2 and 4.3 are located at points with known coordinates X ₁ and Y ₁ , X ₂ and Y ₂ and X ₃ and Y _3, respectively. It also shows the distances D ₁ , D ₂ and D ₃ between the navigation object and the reference radio navigation points, as well as the distances R ₁ , R ₂ and R ₃ between these points and the CPO.

Transmitters 1.1 and 1.2 generate high-frequency harmonic signals with frequencies ω ₁ and ω _2, respectively. Using a common antenna 2 in the direction of the points ORT1, ORT2 and ORTZ, the sum of these two signals is emitted:

These signals are emitted for a period of time sufficient to carry out phase measurements of these signals, which are carried out in the CPU, as will be discussed in more detail below. The signals have the same amplitudes A and random initial phases φ ₁ and φ ₂ .

Using receivers 3.1, 3.2 and 3.3 with antennas 4.1, 4.2 and 4.3, these signals are received at points ORT1, ORT2 and ORT3, located at distances D ₁ , D ₂ and D ₃ from the navigation object, respectively. The signals received at these points are of the form:

where C = 3 · 10 ⁸ m / s is the propagation velocity of radio waves in the atmosphere.

In each of the receivers 3.1, 3.2, and 3.3, through a two-frequency amplifier 11, the signals are fed to a beat frequency generator, which is a combination of a balanced modulator 12, a narrow-band filter 13, and a resonant amplifier 14 tuned to the beat frequency.

) поступает на оба входа балансного модулятора 12. В нем сигнал, по сути, возводится в квадрат, и на выходе каждого балансного модулятора 12 формируется сумма четырех сигналов:Signal S _i (t) ( $$i=\overline{1.3}$$

) arrives at both inputs of the balanced modulator 12. In it, the signal, in fact, is squared, and at the output of each balanced modulator 12 a sum of four signals is formed:

), три высокочастотных гармонических сигнала с частотами, равными 2ω₁, 2ω₂ и (ω₁+ω₂), а также гармонический сигнал с разностной частотой ω_р=|ω₁-ω₂|.At the output of the balanced modulator 12, a signal of zero frequency (constant component) is formed $$A_i^2$$

), three high-frequency harmonic signals with frequencies equal to 2ω ₁ , 2ω ₂ and (ω ₁ + ω ₂ ), as well as a harmonic signal with a difference frequency ω _p = | ω ₁ -ω ₂ |.

, как и высокочастотные составляющие с частотами 2ω₁, 2ω₂ и (ω₁+ω₂), подавляются фильтром 13, а сигнал разностной частоты проходит через него, усиливается усилителем 14 и по проводным линиям связи 5.i поступает на входы усилителей-ограничителей 6.i измерительно-вычислительного устройства, размещенного в ЦПО.The narrow-band filter 13 and the resonant amplifier 14 are tuned to the difference frequency ω _p . Constant component $$A_i^{}$$$${}_2^{}$$

, as well as high-frequency components with frequencies 2ω ₁ , 2ω ₂ and (ω ₁ + ω ₂ ), are suppressed by filter 13, and the difference frequency signal passes through it, is amplified by amplifier 14, and through wire lines 5.i is fed to the inputs of limiter amplifiers 6.i measuring and computing device located in the CPO.

The limiter amplifiers in 6.i normalize the difference frequency signals in amplitude in order to exclude the dependence of the amplitude of the difference frequency signals on the distances between the mobile object and the radio navigation points. In this case, the time and phase relationships between the signals under consideration do not change.

Thus, at the outputs of limiting amplifiers 6.1, 6.2, and 6.3 from difference frequency signals received from the reference radio navigation points ORT1, ORT2 and ORT3, rectangular-shaped signals of the difference frequency ω _p with constant amplitude A are formed:

- знаковая функция;Where

- sign function;

R ₁ , R ₂ and R ₃ are the distances between the CPO and ORT1, ORT2, ORT3, respectively;

With ₁ - the speed of signal propagation in the wire lines connecting the CPO and ORT.

характеризуется основным фазовым сдвигом $${\omega }_p\frac{D_1}{C}$$

, обусловленным прохождением расстояния D₁ от МО до ОРТ1, и дополнительным фазовым набегом

, обусловленным прохождением расстояния R₁, разделяющего ОРТ1 и ЦПО.Signal

characterized by a major phase shift $${\omega }_p\frac{D_{\mathrm{one}}}{C}$$

due to the passage of the distance D ₁ from MO to ORT1, and an additional phase incursion

due to the passage of the distance R ₁ separating ORT1 and CPO.

характеризуется основным фазовым сдвигом $${\omega }_p\frac{D_2}{C}$$

, обусловленным прохождением расстояния D₂ от МО до ОРТ2, и дополнительным фазовым набегом

, обусловленным прохождением расстояния R₂, разделяющего ОРТ2 и ЦПО.Similar signal

characterized by a major phase shift $${\omega }_p\frac{D_2}{C}$$

due to the passage of the distance D ₂ from MO to ORT2, and an additional phase incursion

due to the passage of the distance R ₂ separating ORT2 and CPO.

также характеризуется основным фазовым сдвигом $${\omega }_p\frac{D_3}{C}$$

, обусловленным прохождением расстояния D₃ от МО до ОРТ3, и дополнительным фазовым набегом

, обусловленным прохождением расстояния R₃, разделяющего ОРТ3 и ЦПО.Signal

also characterized by a major phase shift $${\omega }_p\frac{D_3}{C}$$

due to the passage of the distance D ₃ from MO to ORT3, and an additional phase incursion

due to the passage of the distance R ₃ separating ORT3 and CPO.

,

и

можно записать в виде:Signals Received at the CPO

,

and

can be written as:

Where

и

и разность фаз Δψ₂₃=ψ₂-ψ₃ сигналов

и

:In the central processing unit, using a measuring and computing device, namely, using phase detectors 8.1 ... 8.6, analog-to-digital converters 9.1 ... 9.6 and calculator 10, the phase difference Δψ ₂₁ = ψ ₂ -ψ _{1 of the} signals is measured

and

and phase difference Δψ ₂₃ = ψ ₂ -ψ ₃ signals

and

:

As follows from these expressions, the phase differences Δψ ₂₁ and Δψ ₂₃ do not depend on the initial phases of the emitted MO signals φ ₁ and φ ₂ .

и

в уравнениях для разностей фаз Δψ₂₁ и Δψ₂₃ представляют собой фазовые набеги сигналов разностной частоты при их распространении из опорных радионавигационных точек к ЦПО. Они не зависят от пространственного положения объекта навигации и полностью определяются лишь расположением ЦПО относительно точек ОРТ1, ОРТ2 и ОРТ3. Эти величины можно рассчитать заранее.Second terms

and

in the equations for the phase differences Δψ ₂₁ and Δψ ₂₃ are phase incursions of signals of difference frequency during their propagation from the reference radio navigation points to the CPO. They do not depend on the spatial position of the navigation object and are completely determined only by the location of the CPO relative to the points ORT1, ORT2 and ORT3. These values can be calculated in advance.

From the phase differences Δψ ₂₁ and Δψ ₂₃ measured in the CPO, the above-mentioned phase incursions are subtracted:

и

and

As a result, the phase differences of the difference frequency signals are found for the reference points ORT2 and ORT1, as well as ORT2 and ORT3, taking into account phase incursions. These phase differences are used to calculate the distance difference D ₂ -D ₁ and D ₂ -D ₃ , which in turn is used to calculate the coordinates of the navigation object.

An unambiguous determination of the coordinates of the navigation object is possible only in that region of space for which the phase differences Δψ ₂₁ and Δψ _{23 of the} signals of the difference frequency do not go beyond the interval [-π / 2 ÷ π / 2]. This condition is satisfied if, within the specified space region, the distances from any of its points to any of the reference radio navigation points differ by no more than half the wavelength λ _{p of the} signal of the difference frequency ω _p . The region of space for which this condition is satisfied is bounded by the quadrilateral ABEF, the sides of which are the position lines AB, EF, BE, and AF (Fig. 4), the equations of which have the following form:

для линии AF и ( $$-\frac{{\lambda }_{р}}{4}$$

) для линии BE, а параметр L₂ равен $$\frac{{\lambda }_{р}}{4}$$

для линии АВ и ( $$-\frac{{\lambda }_{р}}{4}$$

) для линии EF.where the parameter L ₁ is equal $$\frac{{\lambda }_R}{\mathrm{four}}$$

for line AF and ( $$-\frac{{\lambda }_R}{\mathrm{four}}$$

) for line BE, and parameter L ₂ is $$\frac{{\lambda }_R}{\mathrm{four}}$$

for line AB and ( $$-\frac{{\lambda }_R}{\mathrm{four}}$$

) for the line EF.

To expand the region of unambiguous determination of coordinates, it is necessary to increase the value of λ _p and, therefore, to reduce the value of the difference frequency ω _p . It should be noted that this way of expanding the region of unambiguous determination of coordinates leads to a decrease in accuracy.

,

и

, поступивших в ЦПО из точек ОРТ1, ОРТ2 и ОРТ3, с помощью делителей 7.1, 7.2 и 7.3 частоты дополнительно формируют сигналы масштабной частоты ω_n=ω_ð/n, меньшей разностной частоты в n раз.To prevent a decrease in accuracy in the proposed system, phase measurements are carried out at two frequencies. For this, from the signals

,

and

received in the CPO from the points ORT1, ORT2 and ORT3, using frequency dividers 7.1, 7.2 and 7.3 additionally generate signals of the scale frequency ω _n = ω _ð / n, which is n times less than the difference frequency.

Given that the frequency ω _r alone does not allow us to unambiguously determine the actual phase difference, the actual phase difference Δψ ^Φ for any two signals at a frequency ω _ð is determined by the formulas:

where Δψ _p and Δψ _n are the phase differences of the signals measured directly in the CPO at frequencies ω _p and ω _n ;

int (x) is the integer part of the argument x.

The coefficient k and the actual phase difference Δψ ^Φ are calculated for each of the ORT pairs from the phase differences Δψ _ð and Δψ _n measured in the CPO.

Below is the algorithm for converting the results of phase measurements into the coordinates of the navigation object. This algorithm is applicable for local navigation systems when it is permissible to neglect the sphericity of the Earth, and the propagation velocity of radio waves in the coverage area of the navigation system can be considered constant.

The initial data for the calculation are:

- the phase difference Δψ of ₂₁ signals, measured in the CPO at a frequency ω _n for the radio navigation points ORT1 and ORT2;

- the phase difference _{Δψ n23} signals measured in the DPC at a frequency ω _n for the radio navigation points ORT2 and ORT3;

- phase difference _{Δψ ð21 of the} signals measured in the DPC at the frequency ω _ð for the radio navigation points ORT1 and ORT2;

is the phase difference _{Δψ ð23 of the} signals measured in the CPO at a frequency of ω _ð for the radio navigation points ORT2 and ORT3.

In addition, the following constants are used in the calculation:

- the value of the first high frequency ω ₁ ;

- the value of the second high frequency ω ₂

- the propagation velocity of radio waves in the atmosphere C;

- the propagation speed of the radio signal through the wired channel C ₁ ;

- the distance R ₂₁ between the second ORT2 and the first ORT1 reference radio navigation points;

- the distance R ₂₃ between the third ORT3 and the second ORT2 reference radio navigation points;

- the distances R ₁ , R ₂ and R3 between the CPO and ORT1, ORT2 and ORT3, respectively;

- the coefficient n of the excess of the differential frequency over the scale.

The calculation procedure is as follows:

частоты.1. The difference ω _p = | ω ₁ -ω ₂ | and large-scale $${\omega }_n=\frac{{\omega }_p}{n}$$

frequency.

2. Calculate the difference of the phase incursions of the signals of the difference frequency ω _p when they propagate from the reference radio navigation points to the CPO:

3. The values are calculated:

4. The actual phase differences are calculated:

5. Solve the navigation problem - determine the coordinates of the navigation object:

a) calculate the differences of the distances from the navigation object to the reference points:

here D ₁ , D ₂ , D ₃ are the distances from the navigation object (MO) to the first ORT1, second ORT2 and third ORT3 of the radio navigation aids in accordance with FIG. 3;

b) the differences ΔD ₂₁ and ΔD ₂₃ normalize the lengths of the baselines and calculate the parameter γ:

c) determine the constant parameters:

a = α ₂₁ -α ₂₃ ; b = γΔd ₂₃ -Δd ₂₁ ,

и базовой линией R₂₁;where α ₂₁ is the angle between the axis $$\hat{\gamma }$$

and a baseline of R ₂₁ ;

и базовой линией R₂₃.α ₂₃ - the angle between the axis $$\hat{\gamma }$$

and the base line R ₂₃ .

d) by any of the numerical iterative methods, they solve the equation for calculating the angle β ₂₃ between the base line R ₂₃ and the direction of the navigation object:

cos ( a- β ₂₃ ) -γcosβ ₂₃ = b;

d) calculate the distance D ₂ from the point ORT2 to the navigation object

f) calculate the coordinates of the navigation object in the local rectangular coordinate system, the beginning of which is located at the point ORT2:

If necessary, the coordinates of the navigation object are converted into the original rectangular coordinate system:

The proposed system eliminates the inherent component of the prototype error component due to the error in determining the coordinates of the stationary transmitter of the second harmonic high-frequency signal. In the proposed system, both transmitters are located on a mobile object, and the same antenna is used to emit signals, thereby eliminating the cause of the considered additional error component when measuring the coordinates of a mobile object. Therefore, the accuracy of the measurement of coordinates in the proposed system is higher than in the prototype.

In addition, in the proposed system there is no need for continuous emission of the second harmonic signal, since it can only be emitted at time intervals when the phase differences of the signals of the difference frequency are measured. This time does not exceed fractions of a millisecond. The short radiation time of the signal makes it difficult to detect, and, therefore, suppression by a potential attacker. This significantly increases the noise immunity of the claimed system compared to the prototype.

The fact that in the proposed radio navigation system for measuring the phase difference of the signals, in addition to the difference frequency, an additional scale frequency is formed, n times smaller than the difference frequency, it allows you to significantly expand the area of space in which it is possible to uniquely determine the coordinates of the navigation object, in comparison with the prototype and at the same time not degrade the accuracy of their measurement.

In the proposed system, for such an extension, it suffices to choose the frequency ω _n sufficiently low and the frequency ω _ð sufficiently high.

For the example of FIG. Figure 4 shows two shaded areas of space bounded by quadrangles ABEF and GNMK, respectively, in which an unambiguous determination of the coordinates of the navigation object is possible. The ABEF quadrangle corresponds to a beat frequency that is approximately five times smaller than the GNMK quadrangle.

In the prototype system, the beat frequency does not change during phase measurements. In principle, it can be chosen sufficiently low, for example, equal to ω _{n of the} proposed system, but in this case it should remain so during all phase measurements, and this will lead to a decrease in the accuracy of coordinate measurements, which is already not high enough due to the error in determining the coordinates fixed transmitter.

In the proposed system, phase measurements are carried out not only at a frequency ω _n , but also at a frequency ω _p , which is n times greater, and the final phase measurements are carried out at this higher frequency. In this case, measurements at the frequency ω _n are used only to eliminate the ambiguity of phase measurements. Compared with the prototype, the accuracy of determining the coordinates in the proposed method does not decrease, but increases due to the exclusion of the error in determining the coordinates of a stationary transmitter.

The technical implementation of the system is straightforward.

For the implementation of high-frequency signals, a range of 1200-1400 MHz can be selected. In this range, it is easy to ensure that the narrow-band condition is met when transmitting and receiving two signals and at the same time avoid large energy losses of radio signals in the atmosphere.

As transmitters 1.1 and 1.2 of the signal, integrated microwave amplifiers of the SPF5122Z type can be used, to the inputs of which frequency synthesizers of the ADF4360-5 type are connected.

As antenna 2, a half-wave vibrator can be used, to the input of which a microstrip adder with two inputs is connected.

Each of the receivers 3.1, 3.2 and 3.3 of the signal can be implemented as a set of series-connected two-frequency microwave amplifier type SPF5122Z, a balanced modulator on transistors BFP620, a narrow-band filter on microstrip lines and a resonant amplifier, which can be used as an active second-order bandpass filter on operational amplifier AD797ANZ.

As receiving antennas 4.1, 4.2 and 4.3, half-wave vibrators are used.

As limiting amplifiers 6.1, 6.2 and 6.3, AD8309 logarithmic amplifiers can be used.

Frequency dividers 7.1, 7.2, 7.3 can be implemented on K561IE20 microcircuits.

As phase detectors 8.1 ... 8.6 can be used chips type SYPD-1.

As analog-to-digital converters 9.1 ... 9.6, ADS1210 microcircuits with an AD780 voltage reference can be used.

As the computer 10 can be used 16-bit microprocessor STM32F407.

Claims (1)

A local phase difference-ranging radio navigation system containing a first transmitter of a high-frequency harmonic signal mounted on a navigation object, a second transmitter of a high-frequency harmonic signal that differs in frequency from the first by the value of the beat frequency, and three receivers of these signals with antennas installed at reference radio navigation points with known coordinates, characterized in that the second transmitter is installed, like the first, on the navigation object, while both transmitters are connected As regards to the common transmitting antenna, three channels of wire communication of reference radio navigation points with a central signal processing center and a measuring and computing device located in a central signal processing center, which contains three limiter amplifiers, three frequency dividers, six phase detectors, six analogue, are additionally introduced into the system -digital transducers and the coordinates calculator of the navigation object, while the outputs of the first, second and third receivers are connected through inputs to the inputs with the corresponding limiter amplifiers, the outputs of which are connected respectively to the inputs of the first, second and third frequency dividers and simultaneously with the first inputs of the first, second and third phase detectors, the outputs of the first, second and third frequency dividers are connected to the first inputs of the fourth, fifth and sixth phase detectors, while the second input of the second phase detector is connected to the output of the first amplifier-limiter, the second input of the third phase detector is connected to the output of the second amplifier a la limiter, the second input of the first phase detector is connected to the output of the third amplifier-limiter, the second input of the fourth phase detector is connected to the output of the third frequency divider, the second input of the fifth phase detector is connected to the output of the first frequency divider, the second input of the sixth phase detector is connected to the output of the second a frequency divider, and the outputs of all phase detectors through analog-to-digital converters are connected to the corresponding inputs of the calculator of coordinates of the navigation object.

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