SU1661704A1 - Device for measuring weather-conditioned visibility range - Google Patents

Abstract

The invention relates to meteorology and atmospheric optics, in particular, to devices for determining atmospheric transparency and meteorological visibility range (DVM). To improve measurement accuracy by estimating the degree of atmospheric heterogeneity from a cloud signal and introducing an amendment corresponding to such heterogeneity to the measurement result, unit 11 of signal amplitude dividers, appropriate number of comparators, logic unit 13, and unit 7 for measuring time intervals and variable gain amplifier 14. The device measures the amplitude of the pulsed signal from the cloud, and depending on its magnitude, an amendment is made to the result of the calculation of the MAI. If the amplitude of the signal from the cloud exceeds a certain limit value, the distance to the cloud along the sounding path is taken as the MDW. 1 il.

Description

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The invention relates to atmospheric optics and meteorology and can be used to measure the transparency of the atmosphere, control the meteorological visibility range.

The aim of the invention is to increase accuracy.

The drawing shows the Lok scheme of the proposed device.

The proposed device9 for determining the meteorological visibility range includes a control unit 1, a transceiver 2, gated drives (integrators) 3 and 4, a comparison unit 5, an amplitude analyzer 6, a time interval measurement unit 7, a division block 8 and 9, a logarithmic amplifier 10, a block 11 Delivi, block 12 comparators, block 13 of logic, amplifier 14 with adjustable eMjbM gain, block 15 for measuring the distance to the cloud, selector 16 and recording device 17,

One output of control unit 1 is connected to the input of transceiver 2 and the synchronization input of distance measuring unit 15 to the cloud, and the other output of control unit 1 is connected to the gate inputs of the first integrator 3, comparison unit 5, amplitude analyzer 6, to one of the inputs of measurement unit 7 time intervals.

The output of the transceiver 2 is connected to the inputs of the accumulators 3 and 4, the comparison unit 5, the amplitude analyzer 6 of the distance measuring 15 to the field and the combined input of the comparator unit 12.

The output of the comparator unit 5 is connected to the Gating Input of the accumulator 4 and another input of the time interval measurement unit 7. The outputs of the accumulators 3 and 4 are connected to the corresponding inputs of dividing unit 8, the output of which is connected to one of the inputs of dividing unit 9 through logarithmic amplifier 10, the other input of which is connected to the output of time interval measuring unit 7.

The output of dividing unit 9 through an amplifier 14 with adjustable gain is connected to one of the inputs of the selector 16, the output of the selector 16 is connected to the output of the selector 16, and the output of the distance measuring unit 15 to the cloud, the other output of which is connected to the strobe input, is connected to another input 12 comparators.

One output of the amplitude analyzer 6 is connected to another input of the comparison unit 5, and the other output is connected

to the input of the block 11 dividers.

The outputs of the block 11 of the dividers are connected to the inputs of the block 12 of the comparators, one of the outputs of which is connected to the control input of the selector 16, and

0 others - with the inputs of the logic unit 13, the output of which is connected to the control input of the amplifier 14.

The device works as follows.

5 The control unit 1 starts the transceiver 2, which, at the moment of time tu, sends an impulse of short duration to the atmosphere at the atmosphere, converts the scattered radiation by the atmosphere in the opposite direction

In the direction of the radiation into an electrical signal, it corrects it by the square of the distance to the scattering volume and subtracts the background component. At the time ty, the control unit 1 also starts up the distance measuring unit 15 to the cloud.

An electrical signal from the output of the transceiver 2, proportional to the backscattered signal of the atmosphere, corrected by the square of the distance to the scattering volume, begins to flow to the corresponding inputs of the accumulators 3 and 4, the comparison unit 5, the amplitude analyzer 6, the compressor 12 block. Panel 15 measuring the distance to the cloud,

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At time ta, corresponding to the moment when the probe pulse is completely in the photo field of the receiver photo, i.e., the moment from which the backscattered signal from the atmosphere ceases to depend on the relative position of the transmitter and receiver (t0 - tu const), block 1

5, the control will work out the accumulator 3, which accumulates (integrates) the analog signal from the moment te to the maximum possible time tn. The value tm is determined by the instrumental implementation of the device. By

the expiration of the output time of the drive 3 integral I is fed to one of the inputs of the block 8 division,

At the same time t block t

The control unit 5 starts the time interval measurement unit 7, the amplitude analyzer 6, which is a gated peak detector with a short sampling time, and enables the operation

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block 5 comparison. At time t0, the amplitude analyzer 6 captures the instantaneous value of the backscatter signal. The value of the signal fixed by it is fed to another input of the comparison unit 5.

Comparison unit 5 compares the magnitude of the current signal from the atmosphere and the (1 / n) -th part of the signal magnitude at the time t0 and at the moment t of their equality produces a pulse stopping the operation of the time interval measurement unit 7, the signal from the output of which, after the time tm input block 9 division. The value of n is determined by the specific implementation of the proposed device, the optimal value of which lies within 5-20.

At the same time t, the comparison unit 5 enables the operation of the storage device 4, which integrates the signal up to the time t. After the time tm has elapsed, the integral 1 from the output of accumulator 4 enters another input of block 8 of division. The result of division, proportional to the square of the transparency of the atmosphere layer of thickness c (t - t0) / 2, where c is the speed of light, through a logarithmic amplifier 10 enters another input of the division 9. The result of dividing (t - t0) / ln (Ij / I ,,), proportional to the meteorological visibility range SH, is fed to the input of the amplifier 14 with a variable gain factor.

Blocks 11-13, 15 of the proposed device determine the correction in Sw due to the presence of a cloud (layer) on the sounding path. The magnitude of the correction is determined from the value of the ratio / value of the backscatter signal at the time instant to and the maximum

signal values in the cloud.

The block 15 for measuring the distance to the cloud at the time of the signal from the cloud on the sounding path gives a pulse of resolution to the work of block 12

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The combined input of the comparator unit 12 receives a backscatter signal from the output of the transceiver 2, and the other inputs from the amplitude analyzer 6 through the divider unit 11 different parts of the signal size at time t0.

Block 12 comparators depending on the magnitude of the maximum signal

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from the cloud, issues a command to logic block 13, which changes the gain of amplifier 14. Thus, an amendment is made to the measurement result SI and the selector 16 passes the measurement result to the recording device 17.

If the maximum value of the signal from the cloud exceeds the limit value, i.e., the amendment is meaningless due to its large value, then Sw is taken as the distance to the cloud. After tm, the value is proportional to the distance to the cloud, from the other output of the block 15 goes to another input of the selector 16. On a command from the other output of the block of 12 -comparators, the selector 16 passes this value to the registering device 17.

The specific design of the logic unit 13 depends on the circuit of the amplifier 14 with an adjustable gain factor,

For example, amplifier 14 may be assembled on an operational amplifier, the gain of which is controlled by resistors connected to the feedback circuit using analog switches.

The order of connection of resistors is determined by a digital signal (code, for example, binary) controlling the analog switches.

Then logic block 13 is an encoder on combinational logic that converts the corresponding input code to binary. Such circuits are widely used in all parallel-type analog-to-digital converters.

You can connect (disconnect) resistors, do not convert the output code of the block of 12 comparators to binary. Then, when the next comparator is triggered, the corresponding resistor must be disconnected directly from the feedback circuit. In this case, the logic unit is a set of N-1 devices that adapt the output signals of the respective comparators to the signals that control the corresponding analog keys.

After a time that is known to be sufficient for complete signal processing, all blocks of the proposed device are automatically restored to their original state.

The use of the proposed device due to the automatic correction of the DVM in the case of non-uniformity on the sounding path can significantly improve the accuracy of the DVA measurement.

Claims (1)

Invention Formula A device for determining a Meteor Logical visibility range, comprising a control unit, the first output of which is connected to a transceiver connected to the first inputs of the comparison unit, the first accumulator and an amplitude analyzer, the first input of which is connected to the second input of the comparison unit, the second accumulator The outputs of accumulators are connected to the corresponding inputs of the First division block, and the recorder, which is distinguished by the fact that, in order to improve the accuracy, a divider block, a comparators block, a log block are inserted into it and, a measurement unit {time intervals, a distance measurement unit with a synchronization input and an amplifier with adjustable gain and a selector with control inputs, a logarithmic amplifier and a second dividing unit, with a comparator unit, accumulators, a comparison unit and an amplitude analyzer with gating inputs,. one of the inputs of the second dividing unit is connected to the output of the first dividing unit through a logarithmic effort five Q 0 five five The other input is connected to the output of the time measurement unit, whose inputs are connected respectively to the output of the comparison unit and to the second input of the control unit, also connected to the gating inputs of the first drive, the comparison unit and the amplitude analyzer, and the output of the second division unit through an amplifier adjustable gain is connected to the first input of the selector, the output of which is connected to the recorder, the second input is connected to the first output of the distance measuring unit, the synchronization input The second output is connected to the first output of the control unit, the second output is connected to the gating input of the KOMJ parators unit, and the second input is connected to the output of the transceiver, which is also connected to the input of the comparator unit and the second accumulator, and the second output of the amplitude analyzer is connected to the input of the divider unit, the outputs of which connected to the corresponding inputs of the comparator unit, with one of the outputs of the comparator unit being connected to the third control input of the selector, and the remaining outputs connected to the corresponding odes logic unit, whose output is connected to the control input of the amplifier with adjustable amplification factor 1Ni, wherein the comparing unit output connected to the input of the second gating accumulator.