RU2042146C1 - Direction finder - Google Patents

Abstract

FIELD: navigation. SUBSTANCE: direction finder has two channels 1 and 2 for receiving signals, receiving aerials and 3,3', high frequency amplifiers 4,4', converters 6,6' multiplying units 7,7' reading-out units 8,8' counters 9,9' phase tuning units 10,10' control oscillator 11, by-two frequency divider 12, storer 13, six multipliers, 14, 14', 15, 15', 18, 18', five adders 16, 16', 17, 17', 24, filters 19 and 19', transformed frequency generators 20 and 20', phase shift units 21 and 21', squarers 22, 23, switch 25, lower frequency filters 26, 27, unit 28 for controlling operation of generator, phase meter 29, unit 30 for ranging direction, frequency synthesizer 31. EFFECT: reduced random component of error; improved precision of detection. 3 dwg

Description

 The invention relates to navigation and can be used to determine the direction of a moving object in space.

 A device that provides information on the orientation of the object by measuring information about the phase shift of the signals received from the satellites of the navigation system. The disadvantage of this device is the low accuracy of measuring the phase of the carrier frequency due to the limited time of observation of the signal.

 Known direction finder, which provides the orientation of the object in space by measuring the phase shifts of signals received from satellites on spaced antennas. The disadvantage of this device is the low accuracy of measuring the phase shifts of the received signals due to the limitation of the time of observation of signals from satellites and due to the influence of the measurement channels on each other through a common switch.

 The aim of the invention is to improve the accuracy of measuring the direction of an object in space.

 In FIG. 1 shows a structural diagram of the proposed device; in FIG. 2 embodiment of a direction determination unit; in FIG. 3 block diagram of the algorithm of its operation.

 The direction finder (see Fig. 1) contains two channels for receiving signals 1, 2, two receiving antennas 3, 3 ', two high-frequency amplifiers 4, 4', two frequency converters 5, 5 ', two limiters 6, 6', two multiplying units 7, 7 ', two reading units 8, 8', two counters 9, 9 ', two phase adjustment units 10, 10', a controlled oscillator 11, a frequency divider by two 12, a drive 13, six multipliers 14, 14 ' , 15, 15 ', 18, 18', four adders 16, 16 ', 17, 17', two filters 19, 19 ', two generators of the converted frequency 20, 20', two phase shift units 21, 21 ', two quad 22, 23, third adder 24, lane breakers 25, two low-pass filter 26, 27, the generator control unit 28, fazoizmeritel 29, direction detection unit 30, frequency synthesizer 31.

 Block 30 determining the direction 30 (see figure 2) contains a microprocessor 32, read-only memory 33, random access memory 34, two decoders 35, 36, register 37, three elements And 38, 39, 40, trigger 41.

 The device operates as follows.

 The signal emitted by the satellite is received by antenna 3 of the first channel 1 and fed through the high-frequency amplifier 4 to the frequency converter 5. A signal from the frequency synthesizer 31 is received at the second input of the frequency converter 5. The converted frequency is selected so as not to reach zero at the maximum expected Doppler frequency shift. The converted signal is normalized by amplitude in the limiter 6 so that its output signal takes the value "1" when the threshold value is exceeded, or has the value "0" when it does not exceed the threshold. As a threshold value, a zero amplitude value can be selected. A noise signal (noise) is superimposed on the carrier frequency signal received from the satellite and modulated by the data, the amplitude of which is significantly greater than the amplitude of the modulated carrier signal. The amplitude-normalized signal from the output of the limiter 6 is supplied to the multiplying unit 7, in which this signal is multiplied with the PPC code, read from the drive 13 under the influence of the signal from the frequency divider by two 12. Then the signal obtained from the multiplication is selected in the reader 8 with a doubled frequency from the generator 11. The received signal is fed to the counter 9.

 In the absence of a carrier signal from the satellite, the counting result in the counter 9 increases linearly, and in the presence of a carrier signal at the input of the direction finder with or without a modulating signal. The obtained counting results are continuously received from the counter 9 by two multipliers 14, 15. The multipliers 14, 15 receive signals generated by the transformed frequency generator 20, and those that are regular sequences of "1" and "-1". The frequency of the signal of the generator 20 is equal to the converted frequency and may contain a Doppler shift. The signal for multiplication 15 is shifted relative to the signal for the multiplier 14 by a quarter of the period of the converted frequency in the phase shift unit 21. The output signals of the multipliers 14 and 15 correspond to the “1” and “0” components of the signals and are used to obtain control signals. In the multiplier 18, the total values "1" and "0" are multiplied and fed to the filter 19.

 The output signal of the filter 19 controls the frequency and phase of the signal of the converted frequency generator 20 so that its output signal is equal in frequency and phase to the carrier signal transferred to the converted frequency 7. In the steady state, the sequence of values 1 output from the adder 16 reproduces a modulating signal from which receives data transmitted by a modulating signal from a satellite. The values "1" and "0" are also applied to the squares 22 and 23. The squares of the values "1" and "0" are summed up in the adder 24 and are supplied alternately through the switch 25 to the low-pass filters 26 and 27. The switch 25 is switched at the clock frequency, from which the temporary position of the code selection from the drive 13 is switched. The output signals of the filters 26, 27 are supplied to the control unit of the generator 28, in which the sums and differences of these values are calculated. The signal from the output of block 28 controls the phase of the signal generated by the generator 11. The signal of the generator 11, after dividing by two in the divider 12, controls the selection of the code from the drive 13. The signal of the generator 11 is also a clock signal for the reading block 8. According to the phase difference φ of the output signals of the generators 20 and 20 'determines the direction in space according to the interferometric principle. The phase difference is measured in the phase meter 29 and then evaluated in the block determining the direction 30. The set frequency value is determined at the output of the frequency synthesizer 31.

 The proposed device improves the accuracy of determining an object in space by reducing the measurement error of the difference of the carrier frequency signals received from satellites.

Claims (1)

 Direction finder containing at least two receiving antennas located on one straight line, the first signal receiving channel, consisting of a first high-frequency amplifier, a first frequency converter, a first limiter, a first multiplying unit, a first reading unit, a first counter, the output of which is connected to the first input of the first phase adjustment unit, which also contains a controllable generator, a frequency divider into two, and a drive, the output of which is connected to the second input by the first multiplying unit, the output of the controlled generator is also connected to the second input of the first reading unit, which also contains a phase meter, the output of which is connected to the first input of the direction determination unit, the second and third inputs of which are inputs of the information signal about its own position and the information signal of satellite data, moreover, the number of phase adjustment blocks is equal to the number of receiving antennas of the direction finder, and each phase adjustment block contains the first and second multipliers, the first inputs of which are interconnected and are the first inputs of each phase adjustment unit, the output of the first and second multipliers are connected through the corresponding first and second adders, respectively, to the first and second inputs of the third multiplier, the output of which is through a series-connected first filter, the first generator of the converted frequency and the phase shift unit is connected to the second input of the second multiplier, the second input of the first multiplier is connected to the output of the first generator developed frequency, in addition, the outputs of the first and second adders of the first phase adjustment unit are connected through the corresponding first and second quadrators with the corresponding inputs of the third adder, the output of which is connected to the first input of the switch, the first and second outputs of which are connected respectively to the first and second low-pass filters with the first and second inputs of the generator control unit, the output of which is connected to the input of the controlled generator, while the outputs of the first and second generator in the converted frequency are connected respectively to the first and second inputs of the phase meter, the first output of the direction determination unit is connected to the second input of the switch, characterized in that a second signal receiving channel is introduced into it, made similarly to the first and containing a second high-frequency amplifier in series, a second frequency converter , the second limiter, the second multiplying unit, the second reading unit, the second counter, the output of which is connected to the first input of the second unit phase control Of frequency, a frequency synthesizer is also introduced, the control input of which is connected to the second input of the direction determining unit, and the output with the second inputs of the first and second frequency converters, the first and second antennas are connected to the inputs of the first and second high-frequency amplifiers, the drive output is connected to the second input of the second multiplying unit, the output of the controlled generator is connected to the second input of the second reading unit.

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