RU2524450C1 - Method of detecting optical and optoelectronic surveillance equipment and apparatus for realising said method - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: invention can be used in systems for detecting optical and optoelectronic surveillance equipment in natural conditions and identification thereof. The method comprises, before probing, receiving natural background radiation signals by measuring radiation spectral distribution and determining therein the ratio between intensities of spectral components at three selected wavelengths; generating laser radiation beams at said wavelengths with beam intensity ratio matching the spectral component intensity ratio in the received background radiation; generating a resultant laser radiation beam and performing probing and receiving reflected laser radiation at the three wavelengths and in a wide spectral band; measuring the strength of the received optical signals and determining retroreflection factors for the three wavelengths and for a wide wavelength band; based on said values, forming a spectral portrait of the retroreflection factor, from which optical and optoelectronic surveillance equipment is detected and identified.

EFFECT: high probability of detecting and identifying optical and optoelectronic devices and surveillance equipment and determining association thereof with known classes of optoelectronic devices.

6 cl, 1 dwg

Description

The invention relates to optical and laser ranging, observation systems in the optical range and to quantum electronics.

The invention can be used in surveillance systems for the detection of optical and optoelectronic (OE) devices and means of observation and aiming, as well as to determine the type of detected optical and OE means and their identification.

There is a method of detecting optical and optoelectronic means according to RF patent No. 2133485 [1], which consists in sensing a controlled volume of space with scanned pulsed laser radiation, receiving optical signals from a given range, converting the received signals into a video signal, threshold selection of the received signals, sensing the volume of space with fixed frequency, coding the emitted sequence of laser pulses, detecting an alarm. The disadvantages of this method include the low probability of the correct detection of optical type means with simple threshold processing (selection) of the received signal at a fixed wavelength from the controlled volume of space, as well as the inability to determine the belonging of the detected optical means to a specific class of optoelectronic type means, i.e. recognition of a detected object. The second disadvantage of this detection method is its own vulnerability to the optical detection and recognition of an external observer, because when probing a controlled volume of space (CPC) by pulsed laser radiation at a fixed wavelength, the device that implements the method unmasks itself and can be detected and identified by an external observer that searches for and controls the radiation that irradiates the location of the detection means of this probable third-party observer.

A known method for detecting the eyes of humans and animals according to the patent of the Russian Federation No. 2223516 dated 02/10/2004 [2], which includes irradiating the luminous volume of space with pulsed scanned radiation in the wavelength range of 450-700 microns and determining the eyes by the ratio of the intensities of reflected radiation at two wavelengths -λ ₁ and λ ₂ . The disadvantages of this method include the low reliability of the results, a low probability of correctly determining the presence of a given object, a small range. These shortcomings are due to the lack of definition and compensation of background radiation, which in real conditions can completely change the ratio between the received radiation at λ ₁ and λ ₂ , especially with broadband probe radiation. Another disadvantage of this method is its limited use, which excludes the possibility of its use for the detection and recognition of a wide class of optical and OE devices.

As a prototype, a method for detecting optical and optoelectronic surveillance devices according to the patent of the Russian Federation No. 2278399 [3] was selected.

This method includes sensing the controlled volume of space (CPC) with scanned pulsed laser radiation (LI) at a fixed wavelength, receiving reflected from the CPC LI from a given range, converting the received LI into an electrical signal and threshold processing of the generated electric signal, generating an alarm signal - detection signal object based on threshold processing, determining the distance to the detected object, receiving signals of natural background radiation from the CPC, changing the frequency Thoren LEE, formation of difference signals from the video signal IS and the natural background radiation and the threshold processing, the formation of the composite video signal and converts it into an optical signal for monitoring operator.

The disadvantages of the prototype method include the low probability and effectiveness of the correct detection of optical-electronic type devices and means, as well as the impossibility of recognizing detected objects and determining their belonging to OE devices of the corresponding class. These disadvantages are due to the fact that the actual detection of an object — an OE-type device — is carried out by simple threshold processing of the received reflected signal from the CPC, i.e. based on the excess of the received pulse signal of a certain set level. In this case, a signal reflected from the CPC that exceeds a fixed threshold can also be obtained from a number of objects of natural origin that do not belong to OE-type devices, since the level of the reflected signal at some fixed wavelength of laser radiation cannot be used as a reliable criterion for the detected object to belong to OE-type devices. Various additive manipulations with the level of background radiation and the formation of difference signals also do not lead to an increase in the probability of the correct detection of instruments and means of the OE type.

As a prototype for a device that implements the method, a device that implements the prototype method [3] is selected.

Achievable new technical result is to increase the likelihood of detection and recognition of optical and optoelectronic devices and surveillance tools and determine their belonging to the known classes of OE devices. An additional positive effect is also achieved - reducing the possibility of detection of the proposed device by external observers, including OE-type detection tools.

The specified technical result is achieved as follows.

1. In a method including sensing a controlled volume of space (CPC) with a scanned pulsed laser radiation (LI) at a wavelength of λ ₁ , receiving reflected LI signals and signals of natural background radiation from a CPC, converting the received LI into an electrical signal, its threshold processing and determination range to the detected OESN,

reception of signals of natural background radiation from the CPC is carried out before sensing the CPC, in the received natural background radiation from the CPC, the spectral distribution of radiation is measured, in the measured spectral distribution, the ratio between the intensities W ₁ , W ₂ , W _{3 of the} main spectral components of the color gamut of the visible wavelength range is determined, at a wavelength λ ₁ and at two further wavelengths λ _2, λ _3, the respective intensities of W _1, W _2, W _3, and forming a plurality of optical radiation of white color, generating t beams pulsed LEE at the wavelengths λ _1, λ _2, λ ₃ with the ratio of the beam intensities P _1, P _2, P _3, respective relationships between the intensities of W _1, W _2, W ₃ main spectral component in the spectral distribution of background radiation from the CPC form the total beam by the optical summation LEE beams at wavelengths λ _1, λ _2, λ _3, measure its spectral distribution, compared with the spectral distribution of radiation from natural CPC and adjusting it to achieve equality relations of spectral components of total beam LEE and natural background radiation from the CPC at the wavelengths λ _1, λ _2, λ _3, then carried out CPC-formed beam sensing LEE and reception at the wavelengths λ _1, λ _2, λ ₃ and a wide spectral band Δλ = λ _3- λ ₁ , after converting the received LI to electrical signals and their threshold processing, measure the levels of received optical LI signals, determine the values of retroreflectivity (PSV) for three wavelengths and for the YES band, form a spectral portrait of the PSV of the detected OESN and compare them him with a data bank SPS, based on the comparison, the final detection of OESN and determination of its belonging to a known type of OESN (recognition of OESN) are carried out.

2. The determination of retroreflectivity indicators (PSV) P _i for each of the laser radiation wavelengths λ _i (i = 1, 2, 3) used to illuminate the controlled space (CP) is carried out in accordance with the following formula:

,

,

where E _i is the value of the level of the received optical signal reflected from the CPC at a wavelength λ _i (1 = 1, 2, 3) of the probing CPC LI;

- величина энергии (мощности) зондирующего КОП ЛИ на длине волны λ_i;

- the magnitude of the energy (power) of the probing COD LI at a wavelength of λ _i ;

θ _ni is the beam divergence at the wavelength λ _i (flat angle);

L is the measured distance to the detected object;

D _CR - the diameter (current) of the receiving lens that implements the method of the device;

τ _OMT is the transmittance of the optical-mechanical path of the implementing device;

τ _atm - the transmission of the atmospheric tract at the corresponding wavelength λ _i .

3. The determination of the retroreflectivity index (PSV) P _∆ for a wide wavelength band ∆λ = λ ₃ -λ _{1 of the} probing LI is carried out in accordance with the following formula:

,

,

where E _Δ is the value of the level of the received optical signal reflected from the CPC recorded by the broadband photodetector of the device that implements the method in a wide wavelength band Δλ = λ ₃ -λ ₁ ;

;P _∆ - the total value of the energy (power) LI probing the CPC

;

, τ_{атм ср} - усредненные по длинам волн λ₁, λ₂, λ₃ величины расходимости ЛИ, пропускания оптико-механического тракта и пропускания атмосферы.θ _cf

, τ _{atm cf} are the values of the divergence of the laser radiation, transmission of the optical-mechanical path, and transmission of the atmosphere, averaged over wavelengths λ ₁ , λ ₂ , λ ₃ .

4. To a device for detecting optical and optoelectronic surveillance devices, comprising a scanning unit sequentially arranged on the optical axis, a first laser generator operating at a first wavelength λ ₁ , a first lens, the optical input of which is connected via an optical mirror to the optical input of the scanning unit, the first photodetector, the optical input of which is connected via the first optical filter, the first lens and the second optical mirror to the optical output of the first lens, the first processing unit information, the input of which is connected to the output of the first photodetector, the second lens, the optical axis of which is parallel to the optical axis of the scanning unit, the electrical input of which is connected to the first information processing unit, the second and third laser generators, three controlled optical filters, an optical adder, an optical spectrum analyzer are introduced , four photodetector units, a second information processing unit, a recognition unit, first and second hinged mirrors, three photodetectors, three optical filters, four half there are four optical mirrors and four optical fibers, and the optical input of the optical spectrum analyzer is connected to the optical output of the second lens, the optical output of the optical spectrum analyzer is connected via fiber optic optical fibers to the inputs of four photodetector blocks, the outputs of which are connected to the second block information processing, the optical input of the optical adder through three controlled optical filters, translucent and optical mirrors are associated with the optical outputs of the first, second and third laser generators, the output of the optical adder is connected to the optical input of the scanning unit, and through the first folding mirror, two optical mirrors and the second folding mirror is optically connected to the optical input of the optical spectrum analyzer, the optical output of the first lens is optically coupled to introduced by the second, third and fourth photodetectors through three translucent mirrors, three lenses and three optical filters, the outputs of the second, third and the fourth photodetectors are connected to the inputs of the first information processing unit, the outputs of which are connected to the recognition unit and the second information processing unit, the outputs of which are connected to the control inputs of the first, second and third laser generators, the first, second and third controlled filters and the first and second hinged mirrors.

5. The optical spectrum analyzer is based on an optical diffraction grating.

6. The recognition unit is made on the basis of a digital electronic computer containing a data unit of the values of the reference portraits of the spectral indicators of retroreflection (PSV).

Figure 1 shows a block diagram of a device that implements the proposed method, where the following elements are indicated.

1 - Laser generator operating at a wavelength of λ ₁ (LG)

2; 3 - Laser generators operating at wavelengths λ ₂ and λ ₃

four; 5; 6 - Managed optical filters

7 - Optical adder

8 - Scanning unit

9 - The first lens

10; eleven; 12; 13 - Photodetectors

fourteen; fifteen; 16; 17 - Lenses

18 - The first block of information processing

19 - Second lens

20 - Optical spectrum analyzer

21; 22; 23; 24 - Photodetector blocks (FP)

25 - The second block of information processing

26 - Translucent mirror

27; 28; 29 - Optical mirrors

30 - The first hinged mirror

31 - The control unit of the second hinged mirror

32 - control unit of the first hinged mirror

33 - Second hinged mirror

34; 35 - Optical mirrors

36; 37; 38 - Translucent mirrors

39 - Optical mirror

40; 41; 42; 43 - Optical filters

44 - recognition unit

45 - controlled volume of space (CPC)

46 - optical electronic device (OEP)

47; 48; 49; 50 - fiber optic optical fibers.

In the restrictive part of the claims on the device there are elements, in essence and functions, common with elements of the prototype device, but with different names:

- the first information processing unit, the functions of which in the prototype are performed by the video signal processing unit;

- the first lens in the prototype included in the camcorder;

- the scanning unit, in the prototype, which is part of the laser and provides sensing of the CPC by pulsed LI.

In this case, the second information processing unit is newly introduced and performs a new function of processing optical signals from the output of the optical spectrum analyzer 20 (Fig. 1).

The principle of the method is as follows.

Using the scanning unit 8 (see Fig. 1), the CPC 45 is sensed by a pulsed laser beam simultaneously at three wavelengths λ ₁ , λ ₂ , λ ₃ generated by laser generators (LG) 1, 2, 3. The scanning block is controlled by signals coming from the first information processing unit 18.

Prior to sensing the CPC LI, the spectral distribution of the background radiation from the CPC 45 is measured. To do this, using a second lens 19 directed at the CPC, a continuous reception of natural background radiation is performed. The received background radiation is fed to the input of the optical spectrum analyzer 20, which performs the formation of the spectral distribution of the received radiation in the form, for example, of a spatial optical distributed signal.

Separate spectral components of the generated spectral spatial distribution by means of optical fibers 47 ÷ 50 are received from the output of the optical spectrum analyzer 20 to the inputs of the photodetector blocks 21 ÷ 24, which record the levels of background radiation from the CPC at wavelengths λ ₁ λ ₂ λ ₃ - photodetector blocks 21 ÷ 23 , and also record the level of total background radiation in the spectral range Δλ = λ ₃ -λ ₁ (photodetector block - 24). Information about the levels of the spectral distribution of background radiation at the indicated wavelengths is fed to the input of the second information processing unit 25. The measurement of the spectral distribution of background radiation from the CPC 45 is carried out at three fixed wavelengths λ ₁ λ ₂ λ ₃ , which are selected according to the main components of the color gamut of the visible range wavelengths, namely: λ ₁ - corresponds to the wavelength of red, λ ₂ - the wavelength of green, λ ₃ - the wavelength of blue. Accordingly, λ ₁ = 0.7 μm, λ ₂ = 0.54 μm, λ ₃ = 0.43 μm.

Currently, for these wavelengths there are sources of laser radiation [4]. In the second information processing unit 25, based on the signal intensity levels from the outputs of the photodetector units 21, 22, 23, a relation between the intensities W is determined_one, W₂, W₃ spectral components of background radiation at selected wavelengths, respectively, λ_one λ₂ λ₃. Further, at the moments of time of generation of laser radiation using laser generators pos. 1, 2, 3, a relationship is established between the intensities of the generated laser pulses, respectively, at wavelengths λ_one-P_one (laser generator 1 in figure 1); λ₂-P₂ and λ₃-P₃ corresponding to the relation between the intensities of the spectral components at the corresponding wavelengths λ_one λ₂ λ₃ at the measured spectral distribution of the background radiation from the controlled space volume of the CPC 45. In this case, the following relationship is established between the values (intensities) of the laser pulses generated by the laser generators 1, 2, 3 at wavelengths λ_one λ₂ λ₃: P_one P₂ P₃ and intensities W_one, W₂, W₃ spectral components of background radiation at wavelengths λ_one λ₂ λ₃:

The values of the laser pulses generated by the laser generators 1, 2, 3 are controlled by commands from the second information processing unit 25 entering the laser generators, and formed on the basis of measurements of laser radiation levels from the LI generators using photodetector units 21-24. Next, optical summation of three laser pulses is carried out - laser radiation beams generated by laser generators pos. 1, 2, 3 in figure 1 using an optical adder 7, which receives laser radiation from the outputs of these laser generators. The generated total laser radiation at the output of the optical adder 7 contains spectral components at three wavelengths λ ₁ λ ₂ λ ₃ in a ratio corresponding to the ratio of spectral components in the background radiation of the CPC 45.

Next, they measure the spectral distribution of the generated total laser beam from the output of the optical adder 7 and compare it with the measured spectral distribution of the background radiation from the controlled volume of space. To do this, using the first and second hinged mirrors 30 and 33, the generated radiation from the output of the optical adder 7 is fed to the input of the optical spectrum analyzer 20, which generates a spatial spectral distribution, which is then recorded at wavelengths λ ₁ λ ₂ λ ₃ by means of photodetector blocks 21-23 . Blocks 21-23 similarly record the spectral distribution of background radiation from the CPC 45. Block 24 records the total radiation level in a selected wavelength range Δλ = λ ₃ -λ ₁ . In the second information processing unit 25, the spectral distribution of the total LI beam P ₁₁ , P ₂₁ , P ₃₁ is recorded (taking into account attenuation in the optical elements 7, 28, 29, 30, 33, 20 through which the formed LI passes). Further, the measured distribution of intensities (pulse amplitudes) is compared with the spectral distribution of the background radiation intensity W ₁ , W ₂ , W ₃ from the CPC 45 previously measured and stored in the information block 25. According to the results of this comparison, the LR spectral beam is corrected until the ratio of the spectral components is equal P ₁₁ , P ₂₁ , P ₃₁ at the output of the optical adder 7 to the ratios of the spectral components W ₁ , W ₂ , W ₃ in the measured spectral distribution of the background radiation from the CPC 45.

The correction is carried out using controlled optical filters 4, 5, 6, which receive control signals from the output of the second information processing unit 25, separately for each wavelength λ ₁ λ ₂ λ ₃ . Adjustment of the transmission of controlled filters 4, 5, 6 separately for each wavelength is carried out until the following equality is precisely achieved:

As a result of the correction of the spectral distribution of the generated total beam at the output of the optical adder 7, a laser beam is generated at three fixed wavelengths λ ₁ λ ₂ λ ₃ , forming the color gamut of white light, the spectral distribution of which at the fundamental wavelengths λ ₁ λ ₂ λ ₃ exactly corresponds to the spectral distribution (composition) of these wavelengths in the background radiation from the CPC. The intensity of the laser beams P ₁ , P ₂ , P ₃ formed as a result of this correction at the corresponding wavelengths λ ₁ λ ₂ λ ₃ measured by photodetector blocks 21-23, as well as the value P _Δ in the spectral range Δλ measured by block 24, is stored in the second information processing unit 25.

As a result, in the information processing unit 25, the following energy (or power) values of the pulses of the PI beams P _ni generated by the laser generators and given to the output of the scanning unit 8 are stored:

, i=1, 2, 3; λ₁={λ₁; λ₂; λ₃;},

, i = 1, 2, 3; λ ₁ = {λ ₁ ; λ ₂ ; λ ₃ ;},

далее будут использованы для определения параметров спектрального портрета показателей световозвращения обнаруженного объекта-ОЭП поз.46 в КОП 45. Корректирующие коэффициенты γ_i являются фиксированными техническими параметрами устройства и определяются соответствующими коэффициентами пропускания τ_j оптических зеркал, блока сканирования 8 и спектроанализатора 20, волоконных световодов 47÷50 на соответствующих длинах волн:where γ _i is the corresponding correction coefficient for each wavelength λ _i , which relates the energy (power) of the LI E _i at the corresponding wavelength λ _i , measured in the FP blocks 21 ÷ 24, with the LI energy at the output of the scanning unit 8, t. e. with the magnitude of the energy (power) of the radiation emitted in the direction of the CPC 45. Data measured values

hereinafter, they will be used to determine the spectral portrait parameters of the retroreflectivity of the detected OEP object, item 46 in CPC 45. The correction coefficients γ _i are fixed technical parameters of the device and are determined by the corresponding transmittances τ _{j of the} optical mirrors, scanning unit 8 and spectrum analyzer 20, fiber optic fibers 47 ÷ 50 at the corresponding wavelengths:

,

,

where τ _j is the transmission of the corresponding optical element of the corresponding position in figure 1 at a wavelength of λ _i . For example, τ ₈ is the transmission of the scanning unit 8. The transmission of the mirrors 28, 29 is chosen small enough to attenuate the radiation from the output of the optical adder 7 to the sensitivity level of the photodetector blocks 21-24. Further, this formed total LI beam enters the scanning unit 8, with the help of which probing the controlled volume of space is performed by the scanned pulsed radiation at three wavelengths λ ₁ λ ₂ λ ₃ simultaneously. At this stage, the hinged mirror 30 is not involved in the operation of the optical channel. Next, receive optical radiation reflected from the CPC 45 using the first lens 9 and convert the received radiation into electrical signals using photodetectors 10-12 (figure 1), each of which operates at the corresponding wavelength λ ₁ λ ₂ λ ₃ . The photodetector pos.13 registers radiation in a wide spectral band Δλ = λ ₃ -λ ₁ . In front of each of the photodetectors pos. 10-12, spectral narrow-band filters (for example, interference filters) are installed, for the corresponding wavelength λ ₁ -λ ₃ , pos. 40-43. An optical filter 43 of a neutral type with a wide passband Δλ is installed in front of the photodetector 13. Next, the electrical signals from the outputs of the photodetectors 10-13 enter the first information processing unit 18, in which the threshold processing of each of the electrical signals for the corresponding fixed wavelengths λ ₁ ÷ λ ₃ (photodetectors 10-12), as well as the signal from the output of the photodetector 13, is performed for a wide spectral band Δλ = λ ₃ -λ ₁ . The threshold processing consists in comparing the level (amplitude) ε _{i of the} pulse signal from the corresponding photodetector 10-13 with the threshold level ε _Pi set for a given wavelength λ _i = λ ₁ , λ ₂ , λ ₃ , or with the threshold level ε _П∆ , established for a wide spectral band of reception Δλ. The decision to detect an object in the form of a flashing optical or optical-electronic device is preliminarily taken if the established threshold level is exceeded for at least one of the wavelengths λ ₁ , λ ₂ or λ ₃ at the output of one of the photodetectors pos. 10-12, or if the set threshold level ε _{ПΔ by the} signal from the output of the photodetector 13 operating in a wide spectral band of the reception Δλ:

The threshold levels ε _i in each of the spectral reception channels at wavelengths λ ₁ , λ ₂ , λ ₃ are established before receiving the radiation reflected from the CPC 45, and the threshold level ε _{П∆ is set} in the total spectral channel with a wide spectral band of radiation reception Δλ = λ ₃ -λ ₁ detected by the photodetector 13.

The threshold levels are set in accordance with the sensitivity of the photodetectors used, items 10-13, operating at the indicated discrete wavelengths λ ₁ , λ ₂ , λ ₃ , and a wide range Δλ is the photodetector 13. The threshold levels are set programmatically in the first information processing unit 18 in accordance with the following conditions:

- чувствительность фотоприемника на длине волны λ_i i=1, 2, 3, или фотоприемника 13, работающего в широком спектральном диапазоне ∆λ.where K ₁ is the required signal-to-noise ratio, which, for example, to ensure the probability of correct detection, p = 0.99, is chosen equal to K ₁ = 3;

- the sensitivity of the photodetector at a wavelength λ _i i = 1, 2, 3, or photodetector 13, operating in a wide spectral range Δλ.

представлена здесь в виде уровня мощности (или энергии) импульсного светового излучения на входе фотоприемника 11-13 на соответствующей длине волны λ_i или в диапазоне длин волн ∆λ, при которой на выходе фотоприемника образуется электрический сигнал, равный по амплитуде уровню собственных шумов ε_ш данного фотоприемника, т.е. реализуется величина отношения сигнал/шум, равная единице.Given sensitivity

is presented here in the form of the power level (or energy) of pulsed light radiation at the input of the photodetector 11-13 at the corresponding wavelength λ _i or in the wavelength range Δλ, at which an electric signal is generated at the output of the photodetector, equal in amplitude to the level of intrinsic noise ε _w this photodetector, i.e. a signal-to-noise ratio of one is realized.

After preliminary detection of the object in any of the spectral channels λ _i , or in the broadband reception channel (FP 13), a measurement of the distance L to the detected object is carried out in accordance with the standard procedure for determining the distance from the delay time τ ₁ of the reception pulse relative to the moment of laser pulse emission Sensing CPC 45:

where C is the speed of light.

, выраженной в энергетических единицах.Next, in each of the spectral reception channels λ ₁ , λ ₂ , λ ₃ , Δλ (FP 10-13), the level of the received optical signal E _i is measured relative to the sensitivity level corresponding to the FP pos.1-13

expressed in energy units.

, где E_опрi - запомненный в блоке 18 уровень собственного шумового сигнала данного ФП 10-13, соответствующий уровню энергии (мощности) входного оптического сигнала для этого ФП, равный

, т.е. уровню энергетической чувствительности данного ФП. Далее уровень принятого оптического сигнала на входе ФП E_i и E_∆ определяют по формуле:To do this, in the first information processing unit 18, when registering electrical signals from the outputs of the FP 10-13, the level (amplitude) of the electric signal E _Ei from the output of each FP 10-13 is determined by digitizing and the ratio K _Пшi - signal / noise is determined for each receiving spectral channel equal to the ratio

, where E _opi is the level of the intrinsic noise signal of a given FP 10-13 stored in block 18, which corresponds to the energy level (power) of the input optical signal for this FP equal to

, i.e. level of energy sensitivity of this AF. Next, the level of the received optical signal at the input of the FP E _i and E _∆ is determined by the formula:

where in the last formula the input signal level in the broadband reception channel Δλ is determined (FP 13).

Next, from the measured values of E _i levels of the received optical signal for each wavelength λ _i , i = 1, 2, 3, Δλ determine the value

retroreflectivity indicators (PSV) Pi for a given detected object, the signal from which exceeded the established threshold level in one or more receiving channels (λ ₁ ÷ λ ₃ , Δλ).

The measurement of retroreflectivity i = 1, 2, 3, P _i , is carried out in the first information processing unit 18 on the basis of the indicated measured values of the levels of the received signal in each of the four reception channels (FP 10-13), based on measurements, as well as using the values of the levels of laser pulsed signals generated by laser generators 1-3 and measured by photodetector blocks pos.21-24 (P ₁ , P ₂ , P ₃ ). Between the first and second information processing units, a constant exchange of information is carried out on the communication line connecting them.

The measured values of retroreflectivity (PSV) at three wavelengths, as well as PSV for a wide spectral band P _∆ form a spectral portrait {P _i ; П _∆ } PSV of the reflected signal from the CPC for a given fixed position of the sighting axis of the scanning unit 8 and a fixed point in time at which the reflected pulses of optical radiation were received, the electrical signals from which at the outputs of the FP 10-13 exceeded the set threshold levels in the first information processing unit 18 .

This obtained spectral portrait of retroreflectivity indicators (PSV) P _i , P _{∆ is} used further for more accurate detection and final determination of the presence of optical or optoelectronic devices in the CPC 45 (for a given position in the target axis space of the scanning unit 8). At the same time, the obtained spectral portrait of the PSV allows one to determine whether the detected optoelectronic device belongs to a certain class of optical devices, for example, to determine the presence of an optoelectronic observation device with a television camera, an optical sight, or the presence of an observer with binoculars or a stereo tube.

These OE devices and observation devices have significantly different spectral portraits of PSV in the visible or near infrared range. To realize recognition of the detected object in the CPC 45 according to the measured spectral portrait of the PSV {P _i ; P _∆ } information about the PSV value from the output of the first information processing unit 18 is sent to the input of the recognition unit 44, where the obtained and measured spectral portrait of the PSV {P _i ; П _∆ } with a data bank of spectral portraits of PSV of various types of optical and optoelectronic devices. Based on the results of the comparison, they determine whether the detected optical or OE device belongs to the corresponding class of optical devices of a known type.

Information about the results of the comparison is transmitted to the consumer and displayed on the display of unit 44. At this point, the sensing cycle of the CPC 45 and the detection and recognition of optical and OE devices located in the CPC are completed.

The determination of the spectral portrait of retroreflectivity indicators is carried out in the first information processing unit 18 as follows.

, сформированного лазерным генератором на соответствующей длине волны λ_i и излученного в направлении КОП 45, с величиной энергии E_i принятого импульсного излучения от КОП на соответствующей длине волны λ_i и ряда параметров, характеризующих среду распространения, отражающий объект в КОП, а также ряд геометрических и оптических параметров приемных каналов устройства, реализующего способ:The determination of PSV P _{i is} carried out on the basis of the well-known laser location formula [5], which determines the relationship between the energy (power) of pulsed laser radiation

generated by a laser generator at the corresponding wavelength λ _i and emitted in the direction of the CPC 45, with the energy E _{i of the} received pulsed radiation from the CPC at the corresponding wavelength λ _i and a number of parameters characterizing the propagation medium reflecting the object in the CPC, as well as a number of geometric and optical parameters of the receiving channels of the device that implements the method:

where θ _ni is the divergence of the LI at the wavelength λ _i coincides with the divergence of the LI at the output of the corresponding laser generator (1, 2, 3), which is known from the passport data for the used laser generators pos. 1, 2, 3, or can be obtained from measurements;

L is the distance to the reflecting object in the CPC 45;

S _about - the area of the object, effectively reflecting the LI at a wavelength of λ _i with the divergence of the inverse radiation pattern θ _about and the reflection coefficient at a wavelength of λ _i α _neg ;

_Etc. D - diameter of the receiving lens position 9 in the receiving apparatus 1 that realizes the method;

τ _P - the total transmittance of laser radiation at a wavelength of λ _i , including the following components:

τ _P = τ _OMT · τ _atm , where

τ _OMT — transmission of the optical-mechanical path of the device that implements the method of FIG. 1 in the transmitting and receiving parts of the device (provided that the transmission of the optical-mechanical path is not taken into account in measurements of the energy of the LI pulses emitted and received from the object. In the opposite case, τ _omt = 1).

τ _atm is the transmittance of the atmospheric tract in the direct and reverse propagation of the probe laser radiation at a distance to object L.

This atmospheric transmittance at double range to 2L is determined in accordance with the following evaluation formula:

, где показатель ослабления атмосферы [5]

where is the rate of atmospheric attenuation [5]

L _MDB - meteorological range of visibility, determined from known meteorological tables [5].

, E_i - измеренные мощности (энергии) (3) в излучаемом и принятом импульсе ЛИ на длинах волн λ_i, i=1, 2, 3,Thus, in the presented laser location formula (8), along with the parameters reflecting the characteristics of the object, all other parameters are known or determined and measured as a result of the operation of the device that implements the method: L - measured distance to the object;

, E _i - measured power (energy) (3) in the emitted and received pulse of the laser beam at wavelengths λ _i , i = 1, 2, 3,

The value of L _MDB is entered a priori by the operator on the basis of known tables and based on a visual assessment of atmospheric conditions and time of day during the period of operation of the device that implements the method. The photodetectors pos. 10-13 of FIG. 1 record the energy (level) of the received pulse signals of the LI reflected from the CPC at the corresponding wavelengths of the LI, as well as in a wide band of wavelengths, and convert the level of these signals into electrical form. In electrical form, information about the levels of received LI signals comes from the outputs of photodetectors 10-13 to the inputs of the first information processing unit 18.

In the formula (8), the value

. и известных параметров θ_ni, D_пр, τ_ОМТ и параметра τ_атм, определенного по формуле (9), определяют спектральный показатель световозвращения ПСВ для каждой из используемых длин волн λ_i i=1, 2, 3, в соответствии со следующим соотношением для П_i, получаемым из формул (8-10):by definition, it is an indicator of retroreflectivity of an object observed and illuminated by laser radiation at a wavelength of λ _i . All components included in this value (10) are due to the intrinsic reflective characteristics of the object. Hence, on the basis of formula (8), the measured parameters L, E _i ,

. and the known parameters θ _ni , D _ol , τ _OMT and the parameter τ _atm determined by the formula (9), determine the spectral reflection coefficient PSV for each of the used wavelengths λ _i i = 1, 2, 3, in accordance with the following relation for P _i obtained from formulas (8-10):

where τ _atm from formula (9).

; в качестве величин θ; τ_ОМТ и τ_атм подставляют их усредненные по длине волны значения θ_ср; τ_{ОМТ ср}; τ_{атм ср}.For a wide spectral range of wavelengths Δλ = λ ₃ -λ ₁ , the retroreflectivity index PSV = П _Δ is determined based on the following formula (11-2), in which instead of E _i substitute the value E _{Δ of the} energy (power) of the LI pulse detected by the broadband photodetector pos.13 in the range Δλ; as a value of energy (power)

; as quantities θ; τ _OMT and τ _atm substitute their values averaged over the wavelength θ _sr ; τ _{OMT cf} ; τ _{atm cf.}

The set of measured values of the spectral indices of retroreflection for three wavelengths and the total band ∆λ form a spectral portrait of the retroreflectivity index {П _∆ } П _i for one act of illumination of the element (observed point) of the CPC 45 by three-wave probe radiation.

Thus, in the first information processing unit 18, for each LI pulse emitted and received from the CPC 45 at three wavelengths, the PSV retroreflectivity indices at the corresponding wavelengths λ _{i are} determined from the set of laser wavelengths {λ _i } used to probe the CPC , and for a wide band ∆λ.

Based on the obtained values of the set of values of the retroreflectivity index, a PSV spectral portrait is formed for one act of sensing the CPC by laser radiation at three wavelengths for one specific fixed direction in the space of the sight axis of the scanning unit 8. The obtained value of the PSV spectral portrait is stored in the memory of the first information processing unit 18. Next, the scanning unit 8 switches (directs) its target axis to another (neighboring) point in space (CPC 45), which is illuminated by three waves laser radiation, receiving radiation reflected from the CPC, the reflected and measured levels of the received signals at the wavelengths λ ₁ ÷ λ ₃ and determining spectral portrait PSV by the formulas (11), (11-2), the values which are entered into the memory of the first information processing unit 18 Thus, as a result of sensing CPC LI at three wavelengths for each direction in space from the location of the device that implements the method, towards the CPC and for each point (local) of the observation zone, the CPC measure and form the value of the spectral portrait PSV (if at this point the received signal at least at one wavelength λ _i exceeds the detection threshold set in block 18). The operation of comparing the measured spectral portraits of the PSV with the database in the recognition unit 44 allows for more accurate detection of optical and OE type devices having specific values of the spectral portrait of the PSV, as well as recognition of the detected optoelectronic device - to determine its belonging to a particular class of optical devices, reference values of the spectral portraits of PSV which are stored in the database - in the memory block of the recognition unit 44.

Comparison of the measured spectral portrait of PSV is as follows.

An element-by-element comparison of the retroreflectivity index is carried out in the measured spectral portrait of the PSV and in the reference spectral portrait of the PSV separately for each of the three wavelengths λ _i i = 1 ÷ 3 and the range Δλ, and a difference spectral portrait is formed

- величина показателя световозвращения некоторого эталонного спектрального портрета эталонного оптико-электронного прибора для фиксированной длины волны λ_i,

- эталонная величина ПСВ для диапазона ∆λ.Where

- the value of the retroreflectivity of some reference spectral portrait of a reference optical-electronic device for a fixed wavelength λ _i ,

- reference value of PSV for the range Δλ.

и эталонным спектральным портретом

по формуле:

Then, on the basis of the measured difference spectral portrait R (12), the correspondence parameter F between the measured spectral portrait is determined

and reference spectral portrait

according to the formula:

Further, the specified comparison of the measured spectral portrait of the PSV is carried out for all reference spectral portraits of ^PE stored in the database — memory unit of the recognition unit 44, and the values of the difference portraits R _i (12) and the correspondence parameters F _j (13) are formed for each of the standards in block 44 database (j = 1 ÷ N).

An array of compliance values {F _j ; j = 1 ÷ N} (14).

Further, from one to three values of F _j having the minimum value from all other values of F _{j of the} measured array F _j (14) are selected from the generated array of compliance values (14). In this case, the indicated three minimum values of correspondence F _j = min {F _j j = 1 ÷ N} (15) j = ja _{1 are} determined; ja ₂ ; ja ₃ , by which it is judged that the detected optoelectronic device belongs to the corresponding class of optoelectronic devices.

In the proposed method for detecting optical and optoelectronic devices, sensing of the CPC 45 is carried out simultaneously at three wavelengths λ ₁ ÷ λ ₃ . In this case, LRs at three wavelengths are formed in the visible wavelength range, and the wavelengths are selected corresponding to the main components of the color gamut of the visible range, ensuring the observer perceives the total long-wave radiation {∑λ ₁ , λ ₂ , λ ₃ } as white radiation. In this case, the wavelengths of three laser generators (pos. 1 ÷ 3) and their initial intensities are equal to the following values:

The laser generator (LG) pos. 1 of Fig. 1 generates red radiation (R) with a wavelength of λ ₁ = 0.7 μm with a light flux intensity in a single pulse LI P ₁ , for example, equal to one lumen (lm).

The laser generator pos. 2 generates green radiation (G), with a wavelength of λ ₂ = 0.5 μm and a light flux intensity of P ₃ = 4.59 in arbitrary units, for example lumens, relative to the LH LG pos. 1, generating radiation λ ₁ red.

LG position 3 generates blue radiation (B) with a wavelength of λ ₃ = 0.43 μm and the luminous intensity in the indicated units relative to LG radiation position 1 equal to P ₃ = 0.06. This indicated ratio between the light fluxes P _i i = 1, 2, 3 generated by LG 1 ÷ 3 is the initial one and is established by choosing the appropriate pump levels of the used LG. Moreover, the specified ratio between the intensities of the LG light fluxes P ₁ : P ₂ : P ₃ = P _R : P _G : P _B = 1: 4.59: 0.06 provides the perception of the total light flux (total laser pulse) as white radiation . It should be noted that the perception of the total emitter as white will occur when observing this radiation as an observer with passive observation, for example, using binoculars, and when receiving (observing) the total radiation using optoelectronic devices with a broadband spectral photodetector of the visible range. The indicated ratio of LG radiation intensities and wavelengths was selected in accordance with the well-known colorimetric theory of mixing spectral colors [6].

According to the proposed method, when generating LI at three wavelengths with three different LGs 1 ÷ 3, a relationship is established between the intensities of the generated laser beams P ₁ , P ₂ , P ₃ corresponding to the measured ratio between the intensities W ₁ : W ₂ : W _{3 of the} spectral components on these selected three wavelengths λ ₁ , λ ₂ , λ ₃ in the measured spectral distribution of the background radiation from the controlled volume of space. In this case, the LG pump level 1 ÷ 3 has already been preliminarily selected in accordance with the standard ratio of color radiation intensities in a three-color colorimetric color gamut [6].

Therefore, when performing this operation, only a slight adjustment of the pumping level of LG 1-3 is performed to obtain a ratio between the intensities of the generated laser beams in the first approximation corresponding to the measured ratio between the intensities W ₁ : W ₂ : W _{3 of the} spectral components in the measured background radiation from the CPC 45. Subsequent correction of the spectral distribution of the total luminous flux with the help of controlled filters 5, 6, 4 allows us to ensure exact correspondence of the spectral distribution of the generated the total three-wavelength radiation to the spectral distribution of the natural measured background radiation at the indicated fundamental (color) wavelengths. Using for probing a controlled volume of space 45 of three-wavelength radiation with a spectral distribution corresponding to the spectral distribution of natural background radiation from the CPC, provides the following advantages of the proposed method.

The background radiation from the CPC when it is received by photodetectors 10, 11, 12, operating in the spectral regions with average wavelengths λ ₁ , λ ₂ , λ ₃ does not introduce distortions in the ratio of the intensities (levels) of the received optical signals in the corresponding spectral reception channels, since in these reception channels, the level of background radiation is proportional to the level of radiation of the backlight of the CPC at the corresponding wavelengths and, accordingly, the level of the received optical signal reflected from the CPC. In this case, when registering the radiation reflected from the CPC, the ratio between the levels of the received optical signals (radiation) at different wavelengths λ ₁ , λ ₂ , λ ₃ does not change depending on the levels of background radiation at these wavelengths λ ₁ , λ ₂ , λ ₃ , and are determined only by the parameters (characteristics) of the spectral portrait of the retroreflectivity indices at λ ₁ , λ ₂ , λ ₃ from the detected object, which allows for more accurate recognition and detection of optoelectronic devices (OED) at different levels of background radiation at times personal time of day.

It should be noted that the level of background irradiation and its spectral composition - the ratio between the main (basic) spectral components - vary significantly depending on the height of the Sun above the horizon, time of day, etc. (see, for example, [6] p. 283, Table 15 — color temperature of natural illumination depending on the height of the Sun above the horizon). Therefore, the proposed method for detecting OEP using sensing of optical transmitters by a three-wavelength radiation emitter with a spectral distribution corresponding to the spectral distribution of background natural radiation allows for highly accurate measurement (determination) of the spectral portrait of the retroreflectivity at any time of the day, regardless of the nature and spectral distribution of natural external background radiation. The decrease in the influence of the distribution of background radiation during registration of the received optical signal reflected from the CPC at three wavelengths can be demonstrated as follows.

The recorded optical signal in electrical form at the outputs of the photodetectors 10, 11, 12 J _i i = 1, 2, 3 can be represented as follows:

,

,

where P _u1 , P _u2 , P _u3 are the intensities of laser radiation for illumination of the CPC generated by laser generators and emitted at the corresponding three wavelengths, α ₁ , α ₂ , α ₃ , are the conversion coefficients that relate the level (amplitude) of the emitted pulses of the laser radiation with the value of the received signal in accordance with relation (8), as well as taking into account the sensitivity and transfer characteristics of photodetectors; e ₁ , e ₂ , e ₃ - the level of natural background radiation at the corresponding wavelength LI (i = 1, 2, 3), presented in the form of an electrical (noise) signal at the output of the corresponding photodetector 10-13 in figure 1.

The value α _i i = 1 ÷ 3 contains the value of the measured PSV (11), as well as a number of known parameters determined by the design of the device that implements the method, for example, the diameter of the lens 9.

In accordance with the measured level of the spectral distribution of the background radiation and the intensities P _u1 , P _u2 , P _{u3, the} quantities J _1,2,3 (16) can be represented in the following form:

,

,

. W₁:W₂=1:n₂ where n ₂ , n ₃ are the known and measured in block 25 values of the ratios between the spectral components in the background radiation: W ₁ : W ₂ : W ₃ = e ₁ : n ₂ e ₁ : n ₃ e _1, obtained on condition that the value of e ₁ per unit of reference (baseline background level) when determining the relationships between the spectral components of the background radiation:

. W ₁ : W ₂ = 1: n ₂

Accordingly, we have similar relationships for the intensity of LG radiation P _ui i = 1, 2, 3, set in the same proportions as W ₁ : W ₂ : W ₃ . It can be seen from relations (17) that when the background component increases, for example, at the second wavelength by n ₂ times relative to the background component at the first wavelength, the intensity level of the illuminating CPC LI at this second wavelength also increases by n ₂ times and the effect of level changes background on the ratio of the measured received signals at the first and second wavelengths is reduced, or eliminated, thus, automatic compensation of changes in the background level is realized by a corresponding increase in the intensity level of the illuminating CPC 45 L And at this wavelength. The signal-to-noise (background) ratio in (17) is the same for all three wavelengths (with equal values of α ₁ = α ₂ = α ₃ ), therefore, background radiation will introduce the same errors in measuring the levels of incoming signals and in the measured PSV for all three wavelengths, and will not introduce additional errors in relation to the measured PSV values at three wavelengths, which is important for obtaining reliable information about the spectral portrait of PSV.

, не зависящим от уровня фонового излучения e₁, e₂, e₃, меняющегося в течение суток. Аналогично

. Напомним здесь n₂ и n₃ - измеренные относительные величины фоновых составляющих на второй и третьей длинах волн относительно фоновой составляющей на первой длине волны, принятой за единицу (за базовый уровень отсчета величины фона), e₁, e₂, e₃ - уровни фона на соответствующих длинах волн 1, 2, 3, представленные в электрических сигналах, зарегистрированных на выходах соответствующих фотоприемников поз.10-13.With the same parameters of the reflective characteristics of the object at three wavelengths α ₁ = α ₂ = α ₃ , (test object), we have the ratio J ₁ : J ₂ equal

, independent of the background radiation level e ₁ , e ₂ , e ₃ , changing during the day. Similarly

. Recall here n ₂ and n ₃ are the measured relative values of the background components at the second and third wavelengths relative to the background component at the first wavelength, taken as a unit (as the base level of the background value), e ₁ , e ₂ , e ₃ are the background levels at the corresponding wavelengths 1, 2, 3, presented in the electrical signals recorded at the outputs of the respective photodetectors pos.10-13.

величины фоновой составляющей e₂ (на λ₂), которую в блоке 18 вычисляют на основании имеющейся информации о полосе спектральной чувствительности фотоприемника 11 на λ₂ или о полосе пропускания интерференционного спектрального фильтра 44. Собственно чувствительность фотоприемника 11, а также информация о диаметре приемного первого объектива 9 и пропускании оптического тракта на длине волны λ₂ имеются в блоке 18. Далее осуществляют собственно компенсацию фоновой составляющей в зарегистрированном сигнале J₂ путем вычета в первом блоке обработки информации 18 из величины J₂ полученной оценки фоновой составляющейThus, the measurement of the ratios between the values of α ₁ , α ₂ , α ₃ when receiving and recording the optical signal reflected from the CPC is provided in the proposed method with decreasing the influence of the natural spectral distribution of the background radiation from the CPC existing at the time of the PSV measurement. It should be noted that the measurement of the spectral distribution of background radiation from the CPC using the optical spectrum analyzer 20 and photodetector blocks 21-24 is carried out in the region of the selected wavelengths λ ₁ , λ ₂ , λ ₃ , in some spectral sub-bands Δλ ₁ , Δλ ₂ , Δ λ ₃ , and wavelengths λ ₁ ÷ λ ₃ located in the middle of these ranges. In the first information processing unit 18, after registering the electrical signals J _i (17) from the outputs of the photodetectors 10 ÷ 12, the additive background components e ₁ , e ₂ , e ₃ are compensated for in the registered electrical signals J _i . To do this, they determine (evaluate) the level of the background component e ₂ , which is the most intense spectral component of the natural background radiation at a wavelength of λ ₂ (G is green). The level of this background component is estimated using an optical spectrum analyzer 20 and a corresponding photodetector unit 22 operating at a wavelength of λ ₂ . In this case, as noted earlier, the photodetector unit 22 estimates the level W _{2 of} natural background radiation at a wavelength of λ ₂ in a certain range Δλ. Information about this value W _{2 of the} level of background illumination at a wavelength of λ ₂ , representing a certain average value of the background at λ ₂ for some averaging time, enters the first information processing unit 18, where, based on the value of W ₂ , an average estimate is generated

the magnitude of the background component e ₂ (at λ ₂ ), which is calculated in block 18 based on the available information about the spectral sensitivity band of the photodetector 11 at λ ₂ or about the passband of the interference spectral filter 44. The sensitivity of the photodetector 11 itself, as well as information about the diameter of the receiving first lens 9 and the optical transmission path at the wavelength λ ₂ are in block 18. Next, performed properly compensate the registered background component signal by subtracting J ₂ in the first block obrabot and information from the value of 18 J ₂ estimate obtained background component

The obtained compensated value J _{2K of the} received optical signal at a wavelength of λ ₂ is then used to obtain the value of the retroreflectivity index at a wavelength of λ ₂ .

,

фоновых составляющих осуществляют на основании полученной оценки

средней величины фоновой составляющей для длины волны λ₂ на основании следующих соотношений:In the same way, the background component is compensated for in the recorded electrical signals J ₁ and J ₃ , while the average values are estimated

,

background components are carried out on the basis of the resulting assessment

the average background component for wavelength λ ₂ based on the following relationships:

where n ₂ and n ₃ - in accordance with (17), as indicated, are known and previously measured in block 25, the ratios between the spectral components in the measured natural background radiation. The background compensation in the signal registered at the output of the photodetector 13 operating in a wide spectral band is likewise carried out.

Compensation of background radiation in the recorded signals J _i allows one to increase the accuracy of determining the distribution of the spectral portrait of the PSV and to more accurately determine whether the detected OE device belongs to a specific class of similar devices.

An important advantage achieved by the implementation of the proposed method is the secrecy of the operation of the proposed detection device ECO. This is ensured by the fact that, as mentioned above, the perception of radiation probing the CPC by an external outside observer is realized as a short flash of white color, coinciding in spectral sensation with the background natural radiation in a controlled volume of space, acting at the corresponding moment of observation time and the detection device at a specific time of day and height above the horizon, natural sources of radiation - the sun or moon. Therefore, the radiation of the proposed device will be perceived by an external observer as a random flare from a passive reflector - glass or a metal object that reflects natural background radiation, and the operation of the device, as an active detecting probe laser complex, will not be detected. Similarly, OES reconnaissance with broadband optical photodetectors will perceive the radiation of the proposed device as a reflection of a natural light source from a passive reflector, and not as the operation of a laser probe complex. Therefore, during the work of the proposed method and the device that implements it, secrecy of the operation of the device at any time of the day and the height of the natural light source above the horizon is ensured.

The recognition unit 44 database contains reference spectral portraits of PSVs of various OE devices and observer's OES, obtained experimentally (or by calculation) for various basic (main) spectral wavelengths λ ₁ -λ _{3 of the} visible range and wide wavelength band Δλ, obtained for different heights above the horizon of natural light sources for different times of the day or different seasons of the year (summer, winter, etc.). Moreover, as was noted, the type of an OE device is recognized both on the basis of the formation of a differential portrait of the spectral PSV and on the basis of a comparison of the ratios between the individual spectral components of the PSV in the measured spectral portrait of the PSV from the detected object of the OE device and in the reference PSV from the base block 44 data.

The first, second and third photodetectors 1-12 operate at the above selected wavelengths λ ₁ -λ ₃ . The fourth photodetector, item 13, is broadband and detects optical radiation in the wavelength range Δλ = λ ₃ -λ ₁ . Photodetectors and photodetector blocks are based on a modern element base of photodetector devices. It is possible to use single-element as well as matrix photodetectors of the corresponding wavelength range. Optical filters 40, 41, 42 are narrow-band interference filters at wavelengths λ ₁ , λ ₂ , λ ₃ . the optical filter 43 is broadband and cuts off external background radiation outside the operating wavelength range Δλ. The fourth photodetector, item 13, is designed to determine the optical signal reflected from the CPC 45 in a wide spectral range Δλ when the CPC is illuminated with an optical total signal at three wavelengths corresponding to the backlight of the CPC with white light. This allows you to determine the retroreflectivity index (PSV) of the detected object in the CPC in white light, i.e. in the total (integral) spectral range Δλ for one measurement - one sample of the received level of the reflected optical signal from the CPC recorded by the photodetector 13. This measured PSV by the signal from the photodetector 13 (integral PSV) together with the spectral portrait of the PSV at wavelengths λ ₁ , λ ₂ , λ ₃ allows you to more accurately identify the detected object 46 CPC, as an OE device of the corresponding known type (class) of optical devices.

The proposed device for detecting OE devices is implemented on the basis of standard blocks and nodes. The first and second information processing units 18, 25 are made on the basis of standard electronic computers (PCs) and are equipped with special software that provides for the registration and processing of incoming electrical signals from the outputs of photodetectors and photodetector units, measuring the levels of the corresponding electrical signals, generating threshold levels and performing other operations on the incoming signals, in accordance with the above method operations. In addition, the second information processing unit 25 controls the operation of laser generators and controlled filters, as well as controlling the installation of the first and second hinged mirrors in the optical path. The first information processing unit 18 also controls the operation of the scanning unit 8 and generates control electric signals necessary for controlling the scanning unit.

The recognition unit, item 44, is a specialized electronic computer (PC) and performs determination (calculation) using the given formulas of retroreflectivity indicators (PSV) of the observed and detected objects in the CPC for three wavelengths, determination (calculation) of the PSV (in the band Δλ ) and the formation of the PSV portrait, as well as recognition of the detected object by comparing its measured PSV values and the reference PSV values stored in special memory registers of the recognition unit 44.

The optical spectrum analyzer 20 can be performed on the basis of any known optical spectral device (spectrograph), for example, on the basis of a high-resolution diffraction grating [7]. Photodetector blocks pos.21-24 carry out registration of intensities of the spectral distribution of natural background radiation from the CPC, adopted by the lens 19, at fixed wavelengths λ ₁ , λ ₂ , λ ₃ , as well as in a wide spectral range. The outputs of the optical spectrum analyzer 20 are optically coupled to the photodetector units 21-24 using fiber optic waveguides 47-50. The first and second hinged mirrors 30, 33 are mechanically connected to control units 32, 31, which are, for example, stepper motors controlled programmatically from an information processing unit. The scanning unit 8 is made on the basis of a controlled acousto-optical cell, or on the basis of a reflective mirror rotated by a stepper motor, controlled by signals from the first information processing unit 18.

Thus, the implementation of illumination of the CPC 45 with laser radiation simultaneously at several wavelengths allows you to realize the following advantages: 1. Provides the measurement of PSV observed in the CPC object at several wavelengths. 2. Provides a spectral portrait of the PSV object, which implements an increase in the probability of detection and recognition of the object in the CPC, increase the reliability of classifying the detected object to a known class of OE devices, reduce the influence of background radiation on the measured PSV values and more accurate PSV measurement, which increases the probability of detection and OESN recognition. Measurement of the PSV in a wide range of wavelengths allows you to obtain additional information about the reflective characteristics of the observed object obtained directly by a single photodetector, which complements the information obtained by individual narrow-spectrum photodetectors and, together, provides an increase in the probability of recognition of OE devices in real conditions.

Information sources

[one]. RF patent No. 2133485 dated 07.1998, "Method for the detection of optical and optoelectronic devices."

[2]. RF patent No. 2223516 dated 07.2002, "Method for detecting the eyes of humans and animals."

[3]. RF patent No. 2278399 dated June 16, 2004. “A method for detecting optical and optoelectronic surveillance devices and a device for its implementation” (prototype).

[four]. Handbook of Laser Technology, ed. A.P. Napartovich, Moscow: Gosenergoizdat, 1991

[5]. Signals and interference in a laser location. V.M. Orlov et al., Ed. V.E. Zueva, M .: Radio and communications, 1985

[6]. V.V. Sharonov “Light and Color”, Moscow: Gosfismatlit, 1961

[7]. M. Bourne, E. Wolf, "Fundamentals of Optics", Moscow: Nauka, 1973

[8]. RF patent No. 2380834 from 06.23.2008

Claims (6)

1. A method for detecting optical and optoelectronic observational means (OESN), including sensing a controlled space volume (OPC) with scanned pulsed laser radiation (LI) at a wavelength of λ ₁ , receiving reflected LI signals and signals of natural background radiation from the CPC, converting the received LI into an electrical signal, its threshold processing, detection of AES and range determination,
characterized in that the reception of signals of natural background radiation from the CPC is carried out before sensing the CPC, in the received natural background radiation from the CPC, the spectral distribution of radiation is measured, in the measured spectral distribution, the ratio between the intensities W ₁ , W ₂ , W _{3 of the} spectral components at the wavelength is determined λ ₁ and at two additional wavelengths λ ₂ , λ ₃ corresponding to intensities W ₁ , W ₂ , W ₃ , pulsed pulsed radiation beams are generated at wavelengths λ ₁ , λ ₂ , λ ₃ with a ratio of beam intensities P ₁ , P ₂ , P ₃ corresponding to the ratio between the intensities W ₁ , W ₂ , W _{3 of the} spectral components in the spectral distribution of the background radiation from the CPC, the total LI beam is formed by optical summation of the beams at the wavelengths λ ₁ , λ ₂ , λ ₃ , then the CPC is probed with the generated LI beam and receiving laser radiation reflected from the CPC at wavelengths λ ₁ , λ ₂ , λ ₃ and in a wide spectral band Δλ = λ ₃ ÷ λ ₁ , after converting the received LI into electrical signals and their threshold processing, measure the levels of received optical LI signals, determine the values of retroreflectivity indicators (PSV) at wavelengths λ ₁ , λ ₂ , λ ₃ and for the band ∆λ, from them form a spectral portrait of PSV, by which OESN is detected and recognized. 2. The method according to claim 1, characterized in that the determination of retroreflectivity indicators (PSV) P _i for each of the laser radiation wavelengths λ _i (i = 1, 2, 3) used to illuminate the controlled space (COP) is carried out in accordance with the following formula:

,
where E _i is the value of the level of the received optical signal reflected from the CPC at a wavelength λ _i (i = 1, 2, 3) of the probing CPC LI;

- the magnitude of the energy (power) of the probing COD LI at a wavelength of λ _i ;
θ _ni is the divergence of the LI beam at the wavelength λ _i ;
L is the measured distance to the detected object;
D _CR - diameter (current) of the receiving lens of the implementing device;
τ _OMT is the transmittance of the optical-mechanical path of the implementing device;
τ _atm - the transmission of the atmospheric tract at the corresponding wavelength λ _i . 3. The method according to claim 1, characterized in that the determination of the retroreflectivity index (PSV) P _Δ for a wide band of wavelengths Δλ = λ ₃ -λ _{1 of the} probe LI is carried out in accordance with the following formula:

,
where E _Δ is the value of the level of the received optical signal reflected from the CPC in a wide band of wavelengths Δλ = λ ₃ -λ ₁ registered by the broadband photodetector of the device that implements the method;
P _∆ - the total value of the energy (power) LI probing the CPC

;
θ _cf

, τ _{atm cf} are the values of the divergence of the laser radiation, transmission of the optical-mechanical path, and transmission of the atmosphere, averaged over wavelengths λ ₁ , λ ₂ , λ ₃ . 4. A device for detecting optical and optoelectronic surveillance devices, comprising a scanning unit sequentially arranged on the optical axis, a first laser generator operating at a first wavelength λ ₁ , a first lens, the optical input of which is connected via an optical mirror to the optical input of the scanning unit, first a photodetector, the optical input of which is connected via the first optical filter, the first lens and the second optical mirror to the optical output of the first lens, the first processing unit information, the input of which is connected to the output of the first photodetector, the second lens, the optical axis of which is parallel to the optical axis of the scanning unit, the electrical input of which is connected to the first information processing unit, characterized in that the second and third laser generators, three controlled optical filters, an optical adder are introduced , an optical spectrum analyzer, four photodetector units, a second information processing unit, a recognition unit, first and second hinged mirrors, three photodetectors, three optical fi three, four translucent mirrors and four optical mirrors, as well as four fiber-optic optical fibers, the optical input of the optical spectrum analyzer connected to the optical output of the second lens, the optical output of the optical spectrum analyzer through optical fiber optical fibers connected to the inputs of four photodetector units, the outputs of which are connected to the second information processing unit, the optical input of the optical adder through three controlled optical filters, a translucent and optical mirror Alas are connected with the corresponding optical outputs of the first, second and third laser generators, the optical output of the optical adder is connected to the optical input of the scanning unit, and through the first folding mirror, two optical mirrors and the second folding mirror is optically connected to the optical input of the optical spectrum analyzer, the optical output of the first lens optically connected to the newly introduced second, third and fourth photodetectors through three translucent mirrors, three lenses and three optical filaments trov, the outputs of the second, third and fourth photodetectors are connected to the inputs of the first information processing unit, the outputs of which are connected to the recognition unit and the second information processing unit, the outputs of which are connected to the control inputs of the first, second and third laser generators, the first, second and third controlled filters and the first and second folding mirrors. 5. The device according to claim 4, characterized in that it has an optical spectrum analyzer based on an optical diffraction grating. 6. The device according to claim 4, characterized in that the recognition unit in it is made on the basis of a digital electronic computer containing a data unit of the values of the reference portraits of the spectral indicators of retroreflection (PSV).