RU2484495C1 - Device for determining direction to signal source - Google Patents

Abstract

FIELD: measurement equipment.SUBSTANCE: device for determining direction to a signal source includes the first band-rejection filter and low-pass filter, the second band-rejection filter and low-pass filter, the third band-rejection filter and low-pass filter, the first, the second and the third amplifiers, the first, the second and the third analogue-to-digital converters (ADC), the first, the second and the third signal receivers, a personal electronic calculating machine (PECM or a microprocessor), the first and the second calibrators; it also includes a clock generator, a delay line, an adder, a frequency synthesiser, the first AND circuit, the first register, the second AND circuit, the second register, the first mixer, the first narrow-band filter, the second mixer, the second narrow-band filter, the third mixer, the third narrow-band filter, an antenna unit of the common timing system, a synchroniser, a unit for communication to subscribers, the third calibrator, the third AND circuit, the first synchronous detector, the second synchronous detector, a limiter, a phase shifter, a detector, the first controlled filter, the second controlled filter, the fourth amplifier, the fourth ADC, the third controlled filter, the fourth controlled filter, the fifth amplifier, the fifth ADC, the fifth controlled filter, the sixth controlled filter, the sixth amplifier, the sixth ADC, the first, the second, the third, the fourth, the fifth and the sixth switches, as well as a counter, which are connected to each other in a certain way.EFFECT: reduction of interference at recording of useful short-time signals by means of preliminary search and rejection of frequencies of interference sources.1 dwg

Description

The invention relates to measuring equipment, in particular to direction finders.

A device for determining the direction [1], containing a cathode ray tube, a series-connected first magnetic antenna, a band-pass filter, an amplifier, a synchronous detector and a signal conditioner, a series-connected second magnetic antenna, a band-pass filter, an amplifier, a synchronous detector and a signal conditioner, is sequentially connected electrical antenna, a third band-pass filter, a third amplifier, a phase shifter and a limiter, and the outputs of the latter are connected to the second inputs of the first and synchronous detectors, and the outputs of the signal conditioners are connected to a cathode ray tube.

This device does not provide the ability to select signal sources across the width of the emitted spectrum.

The closest technical solution to the proposed one is a device for determining the direction to the signal source [2], containing a series-connected first magnetic antenna, amplifier, notch filter, low-pass filter and analog-to-digital converter (ADC), series-connected second magnetic antenna, amplifier, notch filter, low-pass filter and analog-to-digital converter, a third electrical antenna connected in series, amplifier, notch filter, low-pass filter often t and an analog-to-digital converter, as well as a personal electronic computer (PC), the first, second, and third high-pass filters connected, respectively, by the outputs to the fourth, fifth, and sixth ADCs, and the inputs, respectively, to the inputs of the first, second and a third low-pass filter, the first and second calibrators associated, respectively, with an electric antenna and magnetic antennas, and inputs connected to a low-frequency signal generator, the outputs of the first, second, third, fourth, fifth and sixth The ADCs are connected to a PC. The device provides a determination of the direction to the signal source by calculating the angle of arrival of the signal relative to the signals of two mutually perpendicular magnetic antennas located in the horizontal plane.

The disadvantage of the prototype is the inability to reduce interference from extraneous signal sources when registering short-term useful signals. In particular, during direction finding and registration of lightning discharges, signals from some official radio stations (for example, signals from the American Omega navigation system, which has transmitters in many places of the globe) fall into the band of received frequencies. Since the amplitude of such a signal is unpredictable, distortion of the useful signal in the presence of such interference is difficult to take into account. In this case, it is advisable to cut out the portion of the interference frequency from the device’s passband, since the dip in the amplitude-frequency characteristic is easier to take into account when analyzing the useful signal.

The technical result provided by the claimed invention is to reduce interference when registering short-term useful signals by preliminary search and rejection of the frequencies of interference sources.

The technical result is achieved by the fact that the device for determining the direction to the signal source, containing serially connected first notch filter and low-pass filter, serially connected second notch filter and low-pass filter, sequentially connected third notch filter and low-pass filter, first, second and third amplifiers, first, second and third analog-to-digital converters (ADCs), first, second and third signal receivers, personal electronic computer (PC or microprocessor), as well as the first and second calibrators, respectively, associated with the first and third signal receivers, and the outputs of the first, second and third ADCs are connected to the PC, additionally contains a series-connected clock, delay line, adder and frequency synthesizer connected in series to the first AND circuit and a first register, connected to a second AND circuit and a second register, connected to a first mixer and a first narrow-band filter, connected in series the second mixer and the second narrow-band filter, the third mixer and the third narrow-band filter connected in series, the antenna unit of the single-time system and the synchronizer connected to the PC, the subscriber communication unit connected to the PC, the third calibrator connected to the second signal receiver and connected PC input, the third “I” circuit, the first synchronous detector, the second synchronous detector, the limiter, the phase shifter, the detector, the first controllable filter connected in series, the second a managed filter, a fourth amplifier and a fourth ADC, connected in series with a third managed filter, a fourth managed filter, a fifth amplifier and a fifth ADC, connected in series with a fifth managed filter, a sixth managed filter, a sixth amplifier and a sixth ADC, the first, second, third, fourth, fifth and sixth keys, inputs connected to the PC, and outputs connected, respectively, to the first, second, third, fourth, fifth and sixth controlled filters, as well as a counter connected to the inputs of the PC, the first the output is connected to the first “I” circuit, and the second output is connected to the second and third “I” circuits, and the first, second and third amplifiers are connected by inputs, respectively, to the first, second and third narrow-band filters, and the outputs are connected, respectively, to the first synchronous detector, the second synchronous detector and the phase shifter, the latter is connected by the output to the limiter and to the detector connected by the output to the third analog-to-digital converter, the inputs of the first, second and third mixers are connected, respectively Naturally, to the first, second and third low-pass filters, the outputs of the first and second synchronous detectors are connected, respectively, to the first and second ADCs, the output of the limiter is connected to the second inputs of the first and second synchronous detectors, the outputs of the first, second, and third signal receivers are connected, respectively, to the first, second and third rejection filters, the outputs of the frequency synthesizer are connected to the first, second and third mixers, the first and second calibrators are connected by inputs to a PC, a clock connected to a personal computer and to the second input of the second “I” circuit, the second register is connected to the personal computer and the output is connected to the adder connected to the personal computer, the first register is connected to the personal computer and the outputs are connected to the second inputs of the third “I” circuit, connected by the outputs to the adder, the output of the second And circuit is connected to the second input of the first And circuit, the inputs of the first, third, and fifth controlled filters are connected, respectively, to the first, second, and third low-pass filters, and the outputs of the fourth, fifth, and sixth ADCs, and control inputs managed filter s connected to the PC.

This embodiment of the device for determining the direction provides the opportunity to pre-scan the frequency range, select the interfering signal sources by the amplitude and width of the emitted spectrum using narrow-band signal reception channels, configure filters and cut the interfering signals in the main, wide-band signal reception channels, and determine the direction for short-term useful a signal in the frequency range with remote frequencies of the interfering signals.

The drawing shows a structural diagram of the proposed device.

Accepted designations:

1 - the first notch filter; 2 - the first low-pass filter; 3 - second notch filter; 4 - second lowpass filter; 5 - third notch filter; 6 - the third low-pass filter; 7 - the first amplifier; 8 - second amplifier; 9 - the third amplifier; 10 - the first analog-to-digital Converter; 11 - the second analog-to-digital Converter; 12 - the third analog-to-digital Converter; 13 - the first receiver of signals; 14 - the second receiver of signals; 15 - the third receiver of signals; 16 - personal electronic computer (PC); 17 - the first calibrator; 18 - second calibrator; 19 - clock generator; 20 - delay line; 21 - adder; 22 - frequency synthesizer; 23 - the first scheme "And"; 24 - the first register; 25 - the second scheme "And"; 26 - second register; 27 - the first mixer; 28 - the first narrow-band filter; 29 - the second mixer; 30 - second narrow-band filter; 31 - the third mixer; 32 - the third narrow-band filter; 33 - antenna unit; 34 - synchronizer; 35 - communication unit; 36 is the third calibrator; 37 - the third scheme "And"; 38 - the first synchronous detector; 39 - second synchronous detector; 40 - limiter; 41 - phase shifter; 42 - detector; 43 - the first managed filter; 44 is a second managed filter; 45 - the fourth amplifier; 46 - fourth ADC: 47 - third controllable filter; 48 - the fourth managed filter; 49 - the fifth amplifier; 50 - fifth ADC; 51 - fifth controlled filter; 52 - the sixth controllable filter; 53 - the sixth amplifier; 54 - sixth ADC; 55 - the first key; 56 - the second key; 57 - the third key; 58 - the fourth key; 59 - the fifth key; 60 - the sixth key; 61 is a counter.

The device for determining the direction to the signal source contains a series-connected first notch filter 1 and a first low-pass filter 2, series-connected a second notch filter 3 and a second low-pass filter 4, serially connected to a third notch filter 5 and a third low-pass filter 6, a first amplifier 7 , the second amplifier 8 and the third amplifier 9, the first analog-to-digital converter (ADC) 10, the second analog-to-digital converter 11, the third analog-to-digital converter 12, the first receiver IR signals 13, a second signal receiver 14 and a third signal receiver 15, a personal electronic computer (PC or microprocessor) 16, a first calibrator 17 and a second calibrator 18, respectively associated with the first and third signal receivers, the outputs of the first, second and the third ADC are connected to the PC, the clock generator 19, the delay line 20, the adder 21 and the frequency synthesizer 22 connected in series, the first AND circuit 23 and the first register 24 connected in series with the second AND circuit 25 and the second register 26, series-connected first mixer 27 and first narrow-band filter 28, series-connected second mixer 29 and second narrow-band filter 30, series-connected third mixer 31 and third narrow-band filter 32, series-connected antenna unit 33 of the single time system (for example, "GPS" or Glonass) and a synchronizer 34 connected to a personal computer, a communication unit 35 with subscribers connected to a personal computer, a third calibrator 36 connected to a second signal receiver and connected to an input to a personal computer, the third AND circuit "37, the first synchronous detector 38, the second synchronous detector 39, the limiter 40, the phase shifter 41, the detector 42, the first controlled filter 43, the second controlled filter 44, the fourth amplifier 45 and the fourth ADC 46 connected in series with the third controlled filter 47, the fourth controlled filter 48, fifth amplifier 49 and fifth ADC 50, connected in series fifth controlled filter 51, sixth controlled filter 52, sixth amplifier 53 and sixth ADC 54, first key 55, second key 56, third key 57, fourth key 58, fifth to yuch 59 and the sixth key 60, the inputs connected to the PC 16, and the outputs connected, respectively, to the first, second, third, fourth, fifth and sixth controlled filters, as well as the counter 61 connected to the inputs of the PC, the first output connected to the first circuit “And”, and the second output connected to the second and third circuits “And”, and the first, second and third amplifiers 7, 8, 9 are connected by inputs, respectively, to the first, second and third narrow-band filters 28, 30, 32, and outputs connected, respectively, to the first synchronous detector 38, in to the second synchronous detector 39 and to the phase shifter 41, the latter is connected by an output to the limiter 40 and to the detector 42 connected by the output to the third analog-to-digital converter 12, the inputs of the first, second, and third mixers are connected, respectively, to the first, second, and third low-pass filters , the outputs of the first and second synchronous detectors are connected, respectively, to the first and second ADCs, the output of the limiter is connected to the second inputs of the first and second synchronous detectors, the outputs of the first, second, and third receiver in the signals are connected, respectively, to the first, second and third rejection filters, the outputs of the frequency synthesizer are connected to the first, second and third mixers, the first and second calibrators are connected by inputs to the PC 16, the clock generator 19 is connected to the PC 16 and to the second input of the second circuit “And”, the second register 26 is connected to the personal computer 16 and the output is connected to the adder 21 connected to the personal computer 16, the first register 24 is connected to the personal computer 16 and the outputs are connected to the second inputs of the third circuit “AND” connected by the outputs to the adder 21, the second output “And connected to the second input of the first circuit "And", the inputs of the first, third and fifth controlled filters are connected, respectively, to the first, second and third low-pass filters, and the outputs of the fourth, fifth and sixth ADCs, and the control inputs of the controlled filters are connected to a PC 16 .

A device for determining the direction to the signal source operates as follows. At the beginning of work, the first register 24, the second register 26, the adder 21 and the counter 61 are reset. When active magnetic antennas are used as the first and second signal receivers, the radio signals arrive at the first antenna 13, which receives the magnetic component of the signal in the North - South direction, to the second antenna 14, which receives the magnetic component of the signal in the West - East direction, and to the third signal receiver, which is used as an active electric antenna 15, receiving the electrical component of the signal and having a circular radiation pattern. The signals from the output of the first magnetic antenna 13 through the first notch filter 1 and the first low-pass filter 2 are supplied to the first mixer 27 together with the signal from the output of the frequency synthesizer 22 are converted into an intermediate frequency with a band determined by the first narrow-band filter 28, amplified by the first amplifier 7 are detected by the first synchronous detector 38, converted into digital information in the first ADC 10 and fed to the PC 16. Similarly, the second mixer 29, the second narrow-band filter 30, the second amplifier 8, the second synchronous detector 39, the second ADC 11 is converted and fed to the PC 16 signals from the output of the second magnetic antenna 14. The signals from the output of the third electric antenna 15 through the third notch filter 5 and the third low-pass filter 6 are fed to the third mixer 31 together with the signal from the output of the synthesizer, the frequencies 22 are converted into an intermediate frequency with a band determined by the third narrow-band filter 32, amplified by the third amplifier 9, adjusted by the phase shifter 41, detected by the detector 42, converted into digital Information in the third ADC 12 is fed to a PC 16. At the same time, the signals from the output of the phase shifter 41 through the limiter 40 are fed to the second inputs of the first and second synchronous detectors. If the specified value is exceeded by a signal from any of the three antennas, the personal computer 16 begins a control cycle for receiving and processing information with a frequency determined by the clock generator 19. At the beginning of the cycle, the personal computer 16 sends the initial value of the number n to the second register 26, which is multiplied by the frequency change step frequency synthesizer 22, sets the reception of the initial frequency of the range within which the scan will be performed. The pulses from the output of the clock generator 19 are supplied to the second register 26 through the second And circuit 25 and through the delay line 20 to the adder 21, where the operation of subtracting from the contents of the second register 26 the contents of the first register 24, halved by sending the number with a shift, without junior level. At the beginning of the cycle, this number is zero, and during scanning, it corresponds to half the width of the spectrum of the source radio signal. The result of the operation goes to the frequency synthesizer 22 and sets the frequency that changes with each step by a predetermined step and goes to the first mixer 27, the second mixer 29 and the third mixer 31. The counter 61 in the zero state prohibits the passage of pulses of the clock generator 19 through the first circuit "And" 23 to the first register 24 and prohibits the transfer of the contents of the first register 24 to the adder 21. If the specified value is exceeded by the amplitude of the radio signal coming from any of the three antennas, the PC 16 generates a signal arriving at the counter 61, which p allows the passage of pulses of the clock generator 19 through the first circuit "And" 23 to the first register 24, but prohibits the transfer of numbers from the first register 24 to the adder 21 using the third circuit "And" 37. This signal is held at the input of the counter 61 for several clock cycles, without changing his condition. If in the next clock cycle there is a decrease in the amplitude of the radio signal below a predetermined value, the counter 61 changes its state, allows the transfer of the contents of the first register 24 to the adder 21 and prohibits the passage of pulses of the clock generator 19 through the first circuit "And" 23 in the first register 24 and through the second circuit " And ”25 to the second register 26. In this case, after the operation of subtracting from the contents of the second register 26 half of the number from the first register 24 on the adder 21 there will be a code corresponding to the reception of the average frequency of the spectrum of the radio signal source ala. The values of the numbers from the adder 21 and the first register 24 are entered in the PC 16, where they are used to calculate the average frequency of the spectrum of the signal source and the width of the spectrum. If the width of the spectrum is greater than the specified value, the results are ignored, and scanning continues, for which the PC 16 resets the first register 24 and changes the state of the counter 61, allowing the clock pulses to pass through the second AND circuit 25 and preventing the signals from passing through the first circuit And ”23 and through the third circuit“ And ”37. If the width of the spectrum is less than or equal to a predetermined value, then the controlled filters 43, 47, 51 are connected by means of the average frequency of the signals entering the PC 16 from the first and second ADCs supply control signals to the keys 55, 57, 59 and the average notch frequency is set by supplying signals to the control inputs of the controlled filters 43, 47, 51. When a second source of the interfering signal appears, controlled filters 44, 48, 52 are connected using the keys 56, 58, 60. n controlled filters can be installed in the device depending on the width of the controlled range and the expected number of “wandering” sources of interfering signals. Notch filters 1, 3, 5 provide the removal of interfering signals with known frequencies, for example, 50 Hz. The number of notch filters can be increased to remove signals from broadcasting stations or transmitters with a constant frequency spectrum. Thus, the frequency of the interfering signals is removed from the frequency range of the useful signals. When a useful signal appears, the direction to the signal source is calculated, for example, by the formula

, $$\alpha =\frac{180}{\pi }arctg\frac{{\mathrm{BUT}}_{\mathrm{one}}}{{\mathrm{BUT}}_2}$$

,

where A ₁ , A ₂ are the amplitudes of the signals of the middle frequency entering the PC 16 from the first and second ADCs, respectively.

The signals from the output of the electric antenna are used to compare with the signals coming from the outputs of the magnetic antennas, as well as to start the device.

The communication unit 35 provides the transmission of digital information to consumers, and the synchronizer 34 provides the reception of GPS or Glonass signals from the antenna unit 33, the binding of information to a single time and support for the time scale in the absence of signals from GPS or Glonass systems.

The proposed device also allows the selection of zones free of radio emission. For this, it is enough in the PC program 16 to change the condition for the signal to be sent to the counter 61 to the opposite, i.e. give it out if the signal is less than the set value.

The proposed device can also be used to determine the direction and selection of signals from sources of signals of a different kind, for example, sound sources, seismic signals, hydroacoustic signals and others, for which it is enough to use signal sensors of a different kind as signal receivers having the required radiation patterns.

Thus, the proposed device for determining the direction to the signal source in comparison with the prototype provides the ability to pre-scan the frequency range, select the interfering signal sources by the amplitude and width of the emitted spectrum using narrow-band channels for receiving signals, adjust filters and notch interfering signals in the main, broadband channels receiving signals, and determining the direction to a short-term useful signal in the frequency range with remote frequencies interfering with the signal .

Information sources

1. "Radio thunder-direction finder", publ. 2006, http://detect-ufo.narod.ru/pribor/detect_radio/pelengatr_01.html

2. I.V. Chernova, G.I. Druzhin, “On the possibility of detecting Kamchatka cyclones by electromagnetic VLF radiation,” IKIR FEB RAS (Paratunka village, Kamchatka region), publ. 2004, http://data.www.ikir.ru/Old/Russian/Science/2004/2-10.pdf

Claims (1)

A device for determining a direction to a signal source, comprising a series-connected first notch filter and a low-pass filter, series-connected a second notch filter and a low-pass filter, series-connected third notch filter and a low-pass filter, first, second and third amplifiers, first, second and the third analog-to-digital converters (ADCs), the first and second signal receivers with radiation patterns similar to magnetic active antennas, oriented respectively in the North-South and West-East directions, the third signal receiver with a circular radiation pattern similar to an electric antenna, a personal electronic computer (PC or microprocessor), which starts a cycle of controlling the reception and processing of information when the specified value is exceeded by a signal from any of these three signal receivers, and when a useful signal appears, the direction to the signal source is calculated, as well as the first and second calibrators associated with ne first and second ADCs, and the outputs of the first, second and third ADCs are connected to a PC, characterized in that it further comprises a serially connected clock generator, a delay line, an adder and a frequency synthesizer, serially connected the first “I” circuit and the first register, serially connected a second “I” circuit and a second register, a first mixer and a first narrow-band filter connected in series, a second mixer and a second narrow-band filter connected in series, sequentially connected a third mixer and a third narrow-band filter, a serially connected antenna unit of a single time system and a synchronizer connected to a personal computer, a communication unit with subscribers connected to a personal computer, a third calibrator connected to a second signal receiver and connected to an input to a personal computer, the third “I” circuit , the first synchronous detector, the second synchronous detector, a limiter, a phase shifter, a detector, a first controllable filter, a second controllable filter, a fourth amplifier and a fourth ADC, connected in series but the connected third controlled filter, fourth controlled filter, fifth amplifier and fifth ADC, connected in series the fifth controlled filter, sixth controlled filter, sixth amplifier and sixth ADC, the first, second, third, fourth, fifth and sixth keys connected to PC inputs, and outputs connected respectively to the first, second, third, fourth, fifth and sixth controlled filters, as well as a counter connected to PC inputs, the first output connected to the first “I” circuit, and the second output connected to the second and third “I” circuits, with the first, second and third amplifiers connected by inputs to the first, second and third narrow-band filters, respectively, and outputs connected to the first synchronous detector, second synchronous detector and phase shifter, the latter is connected to the limiter and to a detector connected by an output to a third analog-to-digital converter, the inputs of the first, second, and third mixers are connected respectively to the first, second, and third low-pass filters, the outputs of the first of the first and second synchronous detectors are connected respectively to the first and second ADCs, the output of the limiter is connected to the second inputs of the first and second synchronous detectors, the outputs of the first, second and third signal receivers are connected respectively to the first, second and third rejection filters, the outputs of the frequency synthesizer are connected to the first , to the second and third mixers, the first and second calibrators are connected by inputs to the PC, the clock generator is connected to the PC and to the second input of the second “I” circuit, the second register is connected to The PC and the output is connected to the adder connected to the PC, the first register is connected to the PC and the outputs are connected to the second inputs of the third “I” circuit, connected by the outputs to the adder, the output of the second “I” circuit is connected to the second input of the first “I” circuit, the inputs the first, third and fifth controlled filters are connected respectively to the first, second and third low-pass filters, and the outputs of the fourth, fifth and sixth ADCs and the control inputs of the controlled filters are connected to a PC.