SU1428030A1 - Device for detecting electromagnetic radiation foretelling an earthquake - Google Patents

Abstract

The invention relates to geophysics, and more specifically to devices for electromagnetic detection — a forerunner of earthquakes in the ultralow frequency range of 0.1–2 kHz and in the very low frequency range (VLF) of 0.5–50 kHz and is intended for use in complex facilities monitoring, recording and forecasting earthquakes. The purpose of the invention is to increase the noise immunity and reliability of detecting the precursor to earthquake. The device contains the first antenna, the first matching amplifier, the first amplifier filter, the first threshold device, the first and second square wave voltage drivers, the second antenna, the second matching amplifier, the second amplifier filter, the second threshold device, the third pulse driver, the first one Ovibrate, key, coincidence circuit, first and second counters, calculator-indicator, clock generator, second one-shot Using a channel of VLF-signals and simultaneously a channel of VLF-pulses as well as signal processing units allow us to calculate the number of cases of N, when the VLF-pulse-atmospherics precede the VLF-pulse, the total number of N VLF-pulses, as well as the difference / N, by the value of which availability of precursor earthquake. 1 il. from S 1C 00

Description

Ltd

The invention relates to geophysics, and more specifically to devices for detecting an electromagnetic precursor of earthquakes in the ultra low frequency range (VLF) 0.1–2 kHz and in the very low frequency band (VLF) kHz and is intended for use in complex surround , control, recording and forecasting of earthquakes.

The purpose of the invention is to increase the norm of the search and reliability of the detection of the precursor of the seventh century

The drawing shows the block device of the device.

The device contains the first antenna 1j first amplifier 1s, the first amplifier 3 first threshold device 4, the first and second drivers 5 6 pulses the second antenna 7, the second matching amplifier-85 second second filter 95 second threshold device 10j the third driver 11 and 1 pulses, the first one-shot 125, the key 13, the matching circuit 14, the first and second counters 15, 16 calculate-pi-indicator 17, the clock generator 18j the second one-shot 19 "

The device works as follows.

The first antenna 1 is vertical, and omnidirectional, together with the first matching amplifier 2 and the first amplifier filter 3, ensures reception of WBC signals in the frequency range 0, kHz. Received signals) T is the form of individual random pulses against the background of the fluctuation component. The first threshold device 4 has a threshold of sensitivity E. the intensity of the vertical electric field, transmits to the bicode shells exceeding in the level of the intensity of the vertical electric field emissions of an alkaline background fluctuation or possible industrial radio interference, commensurate with the level of no more than ten values standard deviation of fluctuation background. The exceeded threshold E, the impulses arrive at the perisan of 5 pulses, which in response to the first positive pilot a positive ejection of the last pulse produces a square and a wave with a constant amplitude and duration St, 3 MCj which exceeds

0

five

O

5 0 45 Q 55

average-duration of the first quasi-half-period of the VLF pulse. The pulses of the first driver 5 pulses to the first input of the coincidence circuit 14, and also to the second driver 6 of pulses, which in response to the pulse of the first driver 5 pulses, produces a rectangular pulse with a constant amplitude and, ESTEMATELY about 20 ms, the value of which with probability close to unity, npeBsinnaet the total duration of any VLF pulse-atmosphere. The second antenna 75 is similar to the first antenna 1 together with the second matching usi. The telephone 8 to the second will amplify the filter 9 to receive signals in the frequency range 3-30 kHz. The received signal is in the form of separate. random VLF atmospheric pulses against the background of the fluctuation component and possible sinusoidal signals of radio stations smaller than the atmospheric ones to be separated. The second threshold device 10 has a sensitivity level E, and transmits pulses exceeding the intensity of the acoustic background and telegraph signals to the output stations. The E level exceeded the threshold, the pulses arrive at the third shaper of 11 pulses, which, in response to the action of each VLF pulse-atmospheric exceeding the threshold EJ, accumulate a rectangular pulse with a constant amplitude and a duration of 1 ms, which ensures the registration of individual VLF pulses atmospheric, without reaction to a separate quasi-half-wave of atmospheric atmospheres, the magnitude of a C 1 1 ms provides, with a probability close to one, the registration of atmospheric pulses without resolving their internal structure. From the output of the third driver 11, the pulses go to the first one-shot 12, which for each input pulse produces a square-wave pulse similar in amplitude and duration, shifted in time by the value t, - Oj3 MCj corresponding to the average anticipation of the VLF-pulse-atmospheric device of its SCH-plots . These pulses come through a normally open key 13 to the second input cxet-jbi 14 coincidence, which expresses the starting pulse when the input pulses coincide in time. The key 13 locks the pulse-at of the atmosphere of the mexico at the time oC, i.e. for the length of time occupied by the VLF-atmos- pheric after the pulse of the first driver 5 pulses. In result & Only those VLF pulses, Q values for the interference conditions of the atmosphere sur- face, which occur directly in front of the VLF pulses front, are passed to the input of the coincidence circuit 14. The first counter 15, operating in the start-stop mode on the observation time interval T in the order of 15-30 minutes, counts the number and virtues N, during the time of the TC on the code

15

14 matches, which corresponds to the number of cases when the OIW-atmosphere-pulse is preceded by a CH I-pulse for a certain time equal to C,. The second counter 16, operating in a similar mode, counts the number of pulses N of the second imaging unit 6 pulses during the same useful time of 2.5 Tz. As a result, the total

the number of VLF pulses in time T ,,. Indicator 17 calculates the absolute difference L / N; j-N / and indicates the values of U; on consecutive, time intervals of observation Тц; h. Clock (nerator 18 vb clock

20

fjQ

Starting pulses with a duration of the order of units of microseconds, followed by a period of time T ". This nmpulp

indicator 17 is triggered by the expiration of each T period; ., which provides read-reset counters 15 and 16 and an indication of the difference U / N ,. For the period T ,,; The starting pulses of the clock generator 18 simultaneously arrive at the second single-vibrator 19, which produces start-up impulses delayed by an interval of about, slightly longer than the duration of the clock pulses of the clock generator 18. Delayed by the starting pulses from the output of the second single-oscillator 19 arrive at the control inputs of the counters 15 and 16 and launch them for the next period. . In the case of the emergence of VLF-pulses of atmospheric precursors of earthquakes, which do not have the characteristic impulses for atmospheric-electric impulses of a combination of VLF-impulse-atmospheric before the front of the VLF pulse, Benii4HHa D; changes in comparison with its values by the size of the M (M Y / 1) pip of the observation time. With an increase in the flow of C 11 H-it. I pulses, at a G-rate of thunderstorm activity or a change in distribution conditions due to solar activity, the value of b; practically does not change and is kept within the limits of L; & where and are the thresholds over a period of time equal to MT ,; ,, Provided / & a decision is made on whether a precursor earthquake occurs. If we denote by P (the probability that the impulse of the VLF of atmospheric interference is preceded by 3 l, 0.3 ms is the ONM-impulse2, 5

atmospheric, and through P the likelihood that the considered circuit does not allow 15 S1GCH pulses to the input of the first counter, preceded by a 01TH-pulse atmospheric, the signal-to-noise ratio of the circuit will be

Jc- (f

1 - P,

where J is 1101N number of N VLF-ig-pulses - the precursor of the seVtne-fjQ trail during the observation time T, to the number N, С LF-11Mt: pulses of atmospheric noise. Vorosity ranges from 0.7 to 0.98, the firing rate, 0.8-0.9.

f o r, M u l a and 3 o b e te n u

g.

A device for detecting electromagnetic radiation — a precursor of the ze1-shek seki, containing the first antenna of the super-frequency band, which connects the antenna to the highly coupled first antenna, the first compliant amplifier, the highest amplification and the first threshold device, and also the content A clock generator, characterized in THAT; In order to improve the noise immunity and reliability of detecting the precursor of the earthquake, the device contains a second PRNH section of the super-low frequency range, the second aicTSHiry, the second matching E95 amplifier, the second amplifier, FM, the second threshold, the three formers of the impulse, , two single-oscillators, a key, a co-fall circuit, a counter, an indicator, iipn this is the output of the first threshold device through nepBbLi form: -a-runate1 -l pulses

51

connected to the second pulse shaper and to the first input of the coincidence circuit the output of the second antenna through a serially connected second antenna amplifier, the second amplifier-filter the second threshold device, the third pulse generator and the first one-oscillator connected to the key input, the control input to the jporo connected to the output of the second pulse driver, and the output

the key is connected to the second input of the coincidence circuit, the output of which is connected to the first counter, the output of the second pulse shaper is connected to the second counter, while the bout of the meters is connected to an indicator, the control input of which is connected to the output of the clock generator, also connected via the second one-shot to the inputs of the first and second counters.

Claims (1)

• R. MODULE OF THE INVENTION A device for detecting electromagnetic and abnormalities in the event of an earthquake containing the first receiving path of the ultralow frequency range, including the first antenna connected in series, the first matching amplifier, the first filter amplifier and the first threshold device, as well as containing a clock generator, characterized in that, in order to increase the noise immunity and reliability of detection of an earthquake precursor, the device contains a second receiving path of the ultralow range ?: frequent m, including · sistent popping second antenna amplifier, a filter, three second threshold pulse shaper novibratora key, two counter circuit indicator output of the first threshold 'through the first formkrovatel.