CS199070B1 - Process for the determination of nuclear explosion size and connection for making thereof - Google Patents

Description

(54) Method for determining the caliber of a nuclear explosion and engaging in its implementation

The invention relates to a method for determining the caliber of a nuclear explosion and to engaging in its implementation.

The time course of the optical radiant flux emitted by a nuclear explosion fireball —3 is characterized by a characteristic short peak of the order of magnitude of 10 3, a steep decline to a minimum and a relatively slow increase to the so-called second maximum. caused by the cooling of the hot gases forming the fireball. The delay of the moments at which the minimum and second maximum radiant flux occurs against the moment of initiation of the explosion is dependent on the so-called caliber of the nuclear explosion, i.e. the caliber of the respective nuclear charge, expressed in suitable units of energy, eg TNT equivalent weight. These delays are approximately proportional to the square root of the caliber.

In the known methods, the caliber is determined just from the position of the minimum or second maximum of the time course. The respective automatic devices determine the moment at which the desired extreme, i.e. minimum or second maximum, occurs, evaluates its delay against the moment of initiation, i.e. practically against the short impulse derived from the first flash or the respective radio pulse accompanying the explosion, and evaluates the caliber.

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The time at which the extreme occurs is determined by the derivative circuits or by means of high-end detectors.

The known solutions have a number of drawbacks. The possibility of using a relatively significant minimum is limited by the low signal level at this time. For more distant explosions, the measurement, and thus the determination of the time at which the minimum occurs, is distorted due to the lack of sensitivity of the device, which must be dimensioned so as not to be damaged by closer explosions at the very intense first or second maximum radiation. In addition, the moment of minimum follows very closely after a strong electromagnetic pulse and a pulsating radiation pulse, which can put electronic parts of the device out of operation for a short time.

When using the second maximum, disadvantages arise from its flatness. Small interfering signals in the electronic evaluation apparatus, possible quantization of measured signal levels during digital information processing, and especially the variable influence of clouds on the illumination of the radiation sensor when the diameter of the fireball changes, can cause a magnitude error when evaluating the caliber from the second maximum.

To a large extent, these shortcomings are eliminated and new possibilities for the use of other types of radiation accompanying the development of a fireball create a method for determining the caliber of a nuclear explosion which evaluates the extreme, i.e., maximum or minimum , for example, in the visible part of the light spectrum, or the corpuscular emission emitted by a fireball. The essence of the method according to the invention is to determine the time interval between the moment of initiation of the explosion and the moment at which the value of the radiant flux density is fixed, that is in a preselected ratio to the value of the evaluated extreme. Since the Time Interval is a function of fixed ratio and caliber of a nuclear explosion, it is given by the caliber of a nuclear explosion.

The method according to the invention is feasible by the circuit according to the invention, which consists of a radiation flux density sensor and an amplification and transformation block. The essence of this circuit is that the output of the amplification and transformation block is connected to the information input of the transformer waveform analyzer, the start input of which is connected to the output of the means for determining the moment of initiation of the nuclear explosion. connected to a device for detecting, recording or transmitting a specified nuclear explosion caliber.

The method of determining the caliber of a nuclear explosion and engaging in its implementation according to the invention achieves the advantage that the dependence of the determined caliber on the deviation of the measured course of the radiant flux density from its theoretical course corresponding to the actual value of the nuclear explosion caliber is substantially reduced. This brings the accuracy of caliber determination closer to the accuracy with which the theoretical courses for different calibers are known.

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The invention will be described, by way of example, of determining the caliber of a nuclear explosion from the course of an optical radiant flux showing the advantages achieved over the prior art.

In the accompanying drawings, FIG. 1 illustrates the waveforms of the radiant flux of optical radiation and the quantity used to determine the caliber. Fig. 2 shows examples of the selection of the characteristics of the thin points on the course of the radiation flux density of any kind. Fig. 3 shows a circuit diagram for carrying out the method of the present invention; and Fig. 4 shows an example of a waveform density analyzer.

In Fig. 1, the curve f ((t) shows the theoretical waveform corresponding to the radiant flux not distorted by disturbing influences. The curve f ₉ (t) shows the result of the actual measurement distorted, for example, by the time-varying influence of the clouds on the ratio of the direct and scattered component of the radiation incident on the sensor. For orientation, a part of the theoretical course f ^ (t) corresponding to four times the caliber is indicated. the time t is calculated from the moment of initiation of the explosion.

The curves f (t) and f ( ₂ ) are characterized by a short first maximum, after which they sink rapidly to a minimum. Then they rise to the second maximum Yj, respectively. Y ₂ , which occurs at moments a T ₂ · In the theoretical course f ^ (t) The relationship between the caliber q and the time corresponding to the maximum Y 1 _ is known from theory and experimental explosions.

This relation is given by function F:

q = F (T) (1)

According to the known method, the evaluation is carried out by substituting the measured value T ₂ in relation (1) and thus calculating the caliber q value:

q = f (t ₂₎ (2)

Function F is approximately quadratic:

Then it applies

ΡίΤ-, Ρ act. TH (3) m2 (4)

Obviously, the relative accuracy of caliber determination is strongly dependent on the relative accuracy of time determination Tg, which in practice is very low for the flatness of the second maximum. It has been found that in the particularly unfavorable mutual configuration of the clouds, the nuclear explosion center and the radiation sensor, the T ₂ / T ₂ ratio can reach values of about 3, which means a mismatch in the caliber determination.

According to the invention, points on the front of the second pulse of radiation, for example, are selected as characteristic points on the curves to be evaluated instead of maxima, so that the respective levels of y are at a predetermined ratio of K: 1 to maximum values of Y.

In the undistorted, theoretical curve f ^ (t), according to FIG. 1, said characteristic point A ^ has the order y-^ = K. Yp where E is the selected constant, and the time coordinate tp

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On curve F ₂ (t), the characteristic point A _{2 has} the order y ₂ = K. Y ₂ , ⁸ The relevant time coordinate tg.

The ratio tg / t ^ is decisive for the relative accuracy of the caliber evaluation. In Fig. 1, the deviation of both values is caused by two reasons: firstly, by shifting the evaluation level, ^y 2 ⁼ ^ 2 ^y l ^{= because of} the maximum level distortion, ie Yj 4 Yg, and secondly because the distortion course occurred also at the moment tp (ie f ^ t ^) / fgít ^).

It follows from simple reasoning that if the ideal course t) can be approximated in the neighborhood of t ^ according to the relation f ^ (t) A at “(5) where a, k are constants and k is equal to the slope tangent to the curve f ^ Ct) on logarithmic paper, then the variation in the evaluation caused by each of the above causes and expressed in terms of -č- These are:

for undistorted maximum (Yj = Y ₂ , = Y ₂ ) and distorted course fg (t) around t = t ^ holds * 2 · (V (6) for distorted maximum (Y ^ / Yg, y ^ / y ₂ ) and the undistorted course of f ₂ (t) in the vicinity of t »ie holds (7), while distortion fg (t) in the neighborhood of t = t ^ i around the maximum then ^f l <* l>

^f 2 ^ P

(i) ⁴ (8)

From the expression (8) it follows from the simple fact that if ee the course of * 1 f ₂ (t) is attenuated equally for all values of time t, ie that fy = “j— to 2 12 then -r ^f · = 1 and the evaluation is absolutely accurate. Thus, the inventive method is insensitive ^X 1 to scaling values evaluated during Al already caused by changing the sensitivity of the device, different distances of a nuclear explosion, or during development fireballs constant even when unknown attenuation of radiation in the atmosphere, e.g. in height explosion above a dense, homogeneous layer of clouds, fog, dust, or when evaluating a low-nuclear diffuse-caliber caliber, if the properties of those areas of the atmosphere that are critical to radiation transmission do not change during the development of the fireball.

Since the effects of attenuation of the radiation incident on the sensor at time t 1 and at the time of the maximum compensate for each other, it is expedient to start from (6) or (7) for assessing the maximum caliber error.

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The magnitude of the constant K depends on the relative evaluation level given by the constant K and also on the wavelength of the radiation, the shorter the wavelength of the evaluated radiation, the sharper the density of spectrally defined radiation increases and the fireball evolves. ° K to 6 000 ° K.

For example, for k = 8, a drop of f ₂ (t) to 32% from f - ^ (t), (6), in the time determination, expressed as a ratio of 10 dB,

2.

0.32

1.15.

Assuming that the time scale of the course of the radiation density with the caliber power, which is in accordance with (3), the ratio of the evaluated caliber increases by the value of q increases proportionally with odq to its theoretical

ie the error of caliber determination in this case is about 30%.

Similarly, according to (7), if the attenuation occurs only around the maximum and again by 10 dB, the error in caliber determination will be - 30%.

Said value of attenuation of the optical radiation at a particular stage of the fireball development, for example if it is caused by the exposure or covering of a part of the fireball with a cloud affecting only direct light incident on the sensor, can be considered a realistic estimate for altitude explosions. Similar changes occur when the sun is alternately covered and uncovered by advancing clouds.

A further reduction in the bend of the evaluation can be achieved by providing the respective measuring device with a filter transmitting only a certain part of the light spectrum, preferably the one which most significantly changes during the development of the fireball. In addition, when using a filter transmitting the shortwave portion of the radiation, the ratio of the scattered component to the direct incident component in the radiation incident on the sensor increases. A further increase in this ratio can be achieved by limiting the field of view of the device to a narrow area around the zenith, so that only scattered light falls on the sensor, except in the unlikely event that a nuclear explosion occurs in the sensor's field of view and destruction.

The described method of caliber evaluation can be modified so that the characteristic points lie on the descending part of the first pulse or the second pulse. The level of characteristic points y can also be determined relative to the minimum curve level, whose precise determination is facilitated by the logarithmic transformation of the measured radiant flux density values.

The described application of the method according to the invention can be generalized to the evaluation of caliber from the electromagnetic radiation flux density waveforms also outside the optical region, in a wide or even narrowly defined spectral region, or from the corpuscular density waveform

199 070 radiant flux, in a wide or even narrowly limited energy band. All the radiation generated by the fireball necessarily has at least one extreme - the maximum, or even more extremes, including at least one minimum. The evaluation according to the invention can be carried out on these courses provided that the theoretical analyzes or experiments show their theoretical dependence on the caliber and that the dependence is sufficiently pronounced. Even in the case of radiation that cannot be influenced by the atmosphere, the use of the method according to the invention is more advantageous than the evaluation from the time when extreme occurs, because the extremes, in particular the maxima of the time courses of quantities in physical processes are always more or less flat, and therefore their position can be poorly evaluated due to relatively small distortions occurring, for example, in the measuring apparatus.

It is also possible to determine the times of several characteristic points of the course which lie on the selected sections of the course and whose ordinates are in defined proportions to the ordinates of the selected extremes. For example, Fig. 2 shows three characteristic points, of which A 1 / / a lies on the ascending part to the extreme Y _{2 of the} course f ₂ (t) and A ₂ 2) lies on the descending part. The respective constants defining the ratio of the ordinates of the characteristic points with respect to the common extreme of Y ₂ J ^are generally different ⁱⁿ this example. Determine the time intervals t ₂ \ 2 * 2> 2 přísluš 2 corresponding to different given ratios of radiant flux density values to the value at the selected extreme Y ₂ and from these time intervals the nuclear explosion caliber is evaluated according to theoretical dependencies, preferably by statistical methods.

Arrangement for performing the method according to the invention is shown in Fig. 3, where the output 101 of the sensor 1 densities is connected to input 201 of the amplifier and the transformation block 2, the output 202 is connected to the information input 301 analyzer £ waveform (f ₂ (t) ) of the transformed signal. The analyzer 6 is provided with a start input 303 and an output 302 which is connected to an input 401 of the evaluation block 6 provided with an output 402.

The sensor signal proportional to the density 1 ₂ f (t) is the radiant flux fireball is input to the amplifier 201 and £ transform block in which the amplified and optionally transformed according to the selected monotone functional dependencies, e.g. logarithmic. The purpose of the logarithm is to achieve a constant relative accuracy with which the output signal of the sensor 1, varying over several orders of magnitude, is displayed at the output 202 of the transformer block 2. In a special case, the amplifier and transformer block 2 can be designed only as a linear amplifier the sensor 1 signal to the quantity fed through the information input 301 to the analyzer 6. In this case, the transformation of the signal fg (t) can only consist of changing the signal level or encoding it in digital form.

Non-linear transformation of the measured and amplified signal, including coding to the digital form, can be performed by a dedicated computer realized eg on the basis of a microprocessor,

199 070 which is then part of the amplification and transformation block 2.

The analyzer g comprises a time information source, e.g., an electronic clock formed from a pulse counter, which is triggered by a start pulse applied to the analyzer input g 303. This start pulse may be derived from, e.g. the impulse accompanying the nuclear explosion. The start pulse corresponds approximately to the moment of initiation of the evaluated explosion. The analyzer evaluates the transformed signal y (f ₂ (t)), determines its maximum value y ⁵ (Y2) ^and Ses t2, corresponding to the value ^ (ΚΥ ₂ ), ie time t ₂ for which ky ₂ = f ₂ ( t), where t ₂ corresponds to a point on the selected segment of the waveform, eg, the rise of the second optical radiation pulse. Time information t ₂ is applied to input 401 of evaluation block 4, to whose output 402 the caliber q information is output. This output can be eg digital and can be connected to a display, printer or computer.

In general, the analyzer g can determine several time t ₂ values corresponding to different characteristic points of the course f ₂ (t), e.g. t ₂ ^ 1 t ₂ ^ ² ^, tg ^ in Fig. 2.

The analyzer g and the evaluation block 4 may be realized by known means, or may be combined into one block, which may comprise a computer.

An example of the connection of the analyzer g for evaluating the caliber from one characteristic point (Ag 1) lying according to Fig. 2 in the downstream part of the waveform fg (t) and for the amplification and transformation block 2 with logarithmic characteristic is shown in Fig. 4.

The analyzer g consists of an extreme detector 31 with an input 304 and an output 305. of a summation member 32 with a first input 306. a second input 307 and an output 308. a level shift source 33 with an output 309. of a comparator 34 with a first input 310. an output 312 and a clock 35 with a start input 314, a stop input 313 and a time information output 315. Transformed log. f ₂ (t) is fed through inlet 301 simultaneously to the inlet 304 of the extreme detector 31 and the inlet 310 of the comparator 34.

At the output 305 of the extreme detector 31, when the maximum is reached, the log Y ₂ signal stabilizes, which, when added together in the summation member 32 with the DC log K signal at the output of the level 33 shift source, changes to the log Y ₂ + signal. log K = = log KY ₂ applied to the second input 311 of comparator 34. Since, in the present case, K <1, the level of KY _{2 is} lower than the log level. Y ₂ .

When the decreasing level of the transformed signal applied to the first input 310 of the comparator 34 becomes equal to the log level. KY _{2 of the} signal at its second input 311. The comparator 34 outputs a logic signal via output 312, which stops input 35 via input 313, which was previously triggered via the above-mentioned start pulse via input 314 identical to analyzer start input 303. At the output 315 stopped 35 hours

199 070 shows time information tg. ^ν ^ ⁸ * ^α Ρ 315 hours gg is in this case identical to the output 302 of the analyzer g.

If the caliber evaluation is to be performed according to a characteristic point on the ascending part of the waveform f ₂ (t), eg according to the point in Fig. 2, the analyzer g can be easily modified. It is provided with a memory in which the transformed waveform is written or, in the case of a digital memory, its samples for a selected sequence of times t ^, where i = 1.2 ..... nan is the total number of samples. This Pamela unlisted in FIG. 3, by means of conventional shift and switching means also to Fig. 4 not described for recording the transformed waveform (f ₂ (t)) connected to the output 202 of the amplifier and the transformation block 2, and then, after for the analysis of the recorded waveform, coupled to the input 304 of the detector 31 and the extreme aa first input 310 of comparator 34. Conventional means also contained in the analyzer 3, ensures reproduction of recorded transformed waveform (f ₂ (t)), in reverse time order.

The time information t ₂ can again be obtained at the output of 315 hours gg, which in this case is provided with means for reversing the operation, which at the beginning of the analysis of the recorded course is provided by the above shifting means via the dedicated clock input gg. . Since, when using random-number digital memory, the sample time t 1 is unambiguously correlated with the address of the respective recorded sample, the address at which the zero or difference sign f ₂ (ti) - KYg was read or changed may be considered to be the caliber being evaluated. This address can therefore be applied to the output 302 of the analyzer g of FIG. 3 by means of appropriate means, and further to the input 401 of the evaluation block 4. In the case of a digital memory and a large range of calibers _{2, it is} advantageous to use non-uniform sequences of sampling moments t, e.g. according to geometric progression. Obviously, when using digital memory, it is preferable to use a digital or hybrid embodiment of the functional blocks constituting the analyzer g.

In general, the transformation of the measured waveform f ₂ (t) may not be logarithmic, as illustrated in the circuit in Fig. 4 for illustration.

Memory utilization in the analyzer g is also advantageous for other reasons, not only in the case of processing the time course f ₂ (t) in the inverse time sequence. E.g. it may be advantageous if the caliber being evaluated is carried out from several characteristic points, or if additional transmission of the measured course is required to an evaluation center equipped with means for more detailed analysis or for complex processing of the results of nuclear explosion observations performed by the network of stations.

The analyzer g including the shifting means and memory can be implemented by a built-in computer, preferably on a microprocessor-based basis. Particularly in this case, it can be combined with the evaluation block 4 or the evaluation block. even with part of the amplification and transformation block 2, some units such as memory, processor and controller may be common to the whole block.

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The method of determining the caliber of a nuclear explosion and engaging in its implementation can be used in systems for evaluating the effects of a nuclear attack.

SUBJECT OF THE INVENTION

Claims (5)

SUBJECT OF THE INVENTION 1. A method for determining the caliber of a nuclear explosion, which evaluates the extreme time course of the radiant flux density in the region of an electromagnetic wave or particle emitted by a fireball, characterized by determining the time interval between the moment of initiation of the explosion and the moment at the value of the density of the radiant flux in a fixed ratio to the value of the evaluated extreme, which time interval is a function of the fixed ratio and caliber of the nuclear explosion. 2. A wiring for carrying out the method according to claim 1, comprising a radiation flow density sensor and an amplification and transformation block, characterized in that the output (202) of the amplification and transformation block (2) is connected to the information input (301) of the analyzer (3). a transformed signal whose start input (303) is connected to the output of the means for determining the moment of initiation of the nuclear explosion and whose output (302) is connected to the input (401) of the evaluation block (4) whose output (402) is connected to indication, recording or transmission of a specified nuclear explosion caliber 3. Connection according to claim 2, characterized in that a memory is interposed between the output (202) of the amplification and transformation block (2) and the input (301) of the waveform analyzer (3). 4. The circuit according to claims 2 and 3, characterized in that interpolation means for interpolating the waveform of the transformed signal between the recorded samples are connected in the waveform analyzer (3). Connection according to Claims 2 to 4, characterized in that the amplification and transformation block (2) is formed by a logarithmic amplifier. 4 drawings