KR101731884B1 - Integrated multi-wavelength remote visibility monitor - Google Patents

Abstract

The present invention aims to provide an integrated multi-wavelength remote visibility measurement device configured to unify the existing device components complicatedly separated and to perform tracking a cause of making the visibility worse, as well as visibility information by use of a plurality of wavelength rays. To achieve this, the present invention includes a transmitter, a reflective mirror, a receiver, and a controller.

Description

[0002] Integrated multi-wavelength remote visibility monitor [0003]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a telemetry measuring device, and more particularly, to a telemetry measuring device capable of integrating device configurations that have been complicatedly separated and configured, , And an integrated multi-wavelength remote correcting meter.

Visibility is defined as 'the longest distance seen by the human eye' and is one of the measures of the turbidity of the atmosphere. More specifically, the visibility in any direction is the maximum distance at which the object at a long distance in the horizontal direction can be normally identified by day, and the maximum distance at which the target can be identified at night Is correct in that direction.

It is one of the factors that is considered to be considerably important when the aircraft is taking off and landing or when the ship is in operation because the basic means that a person driving a vehicle such as a vehicle, a ship, or an aircraft understands the surrounding environment is the naked eye. Visibility is worsened by the presence of gaseous or particulate matter such as fog or dust in the atmosphere. Most of the time deterioration occurs due to light absorption and scattering by particulate matter. In other words, increase of airborne fine dust and ultrafine dust concentration is the main cause of visibility decay. Also, it is well known that visibility damping has a strong correlation with humidity, so that even if the ultrafine dust concentration is the same, the higher the humidity in the air, the worse the visibility tends to deteriorate.

One of the ways of measuring municipalities was the classical method used by the Korea Meteorological Administration (KMA). In other words, the visibility is measured based on the object that is farthest from the reference point by referring to the visibility target map created by using the building or mountain which knows distance information at each measurement site as an index. However, this method has a disadvantage in that it requires a lot of manpower, deviates according to the measurer, and the measurement interval is not dense.

Various methods have been introduced to overcome these limitations. For example, Korean Patent Registration No. 0715140 ("Visibility Measuring Apparatus and Method", Apr. 30, 2007), Korean Patent Publication No. 2012-0105966 Measuring Apparatus and Method Thereof ", Sep. 26, 2012). The visibility measuring device according to the preceding documents uses a principle similar to the visibility measurement using human's eyes but uses a camera instead of the naked eye and a judgment based on the lightness or roughness change criterion instead of human judgment, . However, the apparatus of this type requires a relatively large number of apparatuses, which unnecessarily increases the volume and cost of the apparatus, and has a problem of insufficient accuracy, precision and objectivity.

An optical-based viscometer was introduced as a more advanced method. The optical viscometer is a device that calculates the visibility by using the principle that the light irradiated to the atmosphere is attenuated by absorption or scattering of gas phase or particulate matter. It calculates the light extinction coefficient from the attenuated amount of light and calculates it by the Koschmieder equation To calculate the visibility.

Conventional optical viscometers are divided into telemetry and field measurement. The remote measurement method is a method of calculating the correctness by receiving the light from the transmitter at a distance of 1 km or more. The field measurement method is a method in which the transmitter and the receiver are tilted at a very short distance, And the signal is scattered and the signal is obtained from the signal obtained at the receiver. The telemetry method has a merit that it is possible to calculate the visibility even on a relatively clear day, such as in urban areas, but it is disadvantageous in that the transmitter and the receiver must be separated from each other. On the other hand, the field measurement method has a disadvantage in that it can be measured only in fog or high concentration.

In addition, as described above, the attenuation of visibility has a strong correlation with not only the concentration of fine dust but also the humidity. In the case of the conventional visibility measuring device, it is difficult to clearly determine whether the deterioration factor of visibility is in the fine dust concentration or in the humidity there was.

1. Korean Patent No. 0715140 ("Visibility Measurement Apparatus and Method", 2007.04.30) 2. Korean Patent Laid-Open Publication No. 2012-0105966 ("Visual Distance Measuring Apparatus and Method ", September 26, 2012)

1. Jinsang Jung, Y. J. Kim, K. Y. Lee, M. G.-Cayetano, T. Batmunkh, J.-H. Koo, and J. Kim, 2010. Spectral optical properties of long-range transport. Asian Dust and Pollution Aerosols over Northeast Asia in 2007 and 2008, Atmospheric Chemistry and Physics, 10 (12), 5391-5408.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method and apparatus for integrating apparatuses which have been complicatedly separated and integrated, And a tracking error deterioration factor can be performed.

According to an aspect of the present invention, there is provided an integrated multi-wavelength remote tactometer (100) including a first light source (L1) for emitting a first light having a first wavelength and a second light source A second light source (L2) for emitting a second light; a transmission unit (110) including a transmission optical system for collecting the first light and the second light and emitting the parallel light; A reflector 120 for reflecting light emitted from the transmitter 110; A receiving optical system for receiving the light reflected by the reflecting mirror 120, a third photodetector D3 for detecting the first light, and a fourth photodetector D4 for detecting the second light, A receiving unit 130 integrally connected to the antenna 110; A correction for each of the first wavelength and the second wavelength is calculated using the intensity of the light irradiated by the transmitter 110 and the intensity of the light detected by the receiver 130 and the visibility decay principal is calculated using the calculated correction values A control unit 140 for judging whether or not the vehicle is running; . ≪ / RTI > At this time, it is preferable that the first light is visible light and the second light is infrared light.

The transmission optical system reflects a part of the first light emitted from the first light source L1 and transmits a part of the second light emitted from the second light source L2, A first beam splitter (BS1) arranged to irradiate a part of the emitted first reflected light and a part of the second transmitted and emitted light from the second light source (L2) in the same direction; A first telescope part (T1) for gathering first light and second light traveling through the first beam splitter (BS1) and irradiating the first light and the second light as parallel light; . ≪ / RTI > Also at this time, the transmitting optical system is arranged to reflect the remaining part of the first light transmitted through the first beam splitter BS1 and transmit the remaining part of the second light reflected from the first beam splitter BS1 A second beam splitter BS2; A first photodetector (D1) for detecting a remaining portion of the first light reflected by the second beam splitter (BS2); A first filter (BP1) disposed on an optical path between the second beam splitter (BS2) and the first photodetector (D1), the first filter (BP1) having a first wavelength as a center wavelength and selectively transmitting only a predetermined wavelength; A second photodetector (D2) for detecting a remaining portion of the second light transmitted through the second beam splitter (BS2); A second filter (BP2) disposed on the optical path between the second beam splitter (BS2) and the second photodetector (D2) and selectively transmitting only a wavelength within a predetermined range, the second wavelength being a center wavelength; As shown in FIG.

The receiving optical system may further include: a second telescope part (T2) for receiving the light reflected by the reflecting mirror (120); And reflects a part of the first light included in the light received by the second telescope part T2 and transmits the reflected light to the third photodetector D3, A third beam splitter (BS3) arranged to transmit a portion of the light and to transmit to the fourth photodetector (D4); A third filter (BP3) disposed on an optical path between the third beam splitter BS3 and the third optical detector D3, the third filter BP3 having a first wavelength as a center wavelength and selectively transmitting only a predetermined wavelength range; A fourth filter BP4 disposed on the optical path between the third beam splitter BS3 and the fourth photodetector D4 and having a second wavelength as a central wavelength and selectively transmitting only a predetermined wavelength range; . ≪ / RTI >

The reflector 120 may be a retro-reflector.

The controller 140 measures the intensity of the light emitted from the first light source L1 and the second light source L2 by the transmitter 110 and transmits the light intensity measured by the receiver 120 to the reflector 120 The optical intensity of the reflected first light and the reflected second light can be measured and the visibility can be calculated for each of the first light and the second light using the following equation.

,(At this time,

,

Calibration coefficient (I ₀ ): The light intensity measured by the receiver 130 when there is no airborne contaminant,

Actually Measured Light Intensity (I): The light intensity measured by the receiver 130 when measured,

Light distance: a sum of the distance from the transmitter 110 to the reflector 120 and the distance from the reflector 120 to the receiver 130)

The control unit 140 repeatedly turns on / off the first light source L1 and the second light source L2 at predetermined periods, and when the light source unit 130 is turned on, And the light intensity signal obtained by removing the background signal from the acquired signal is referred to as a processed signal, the optical intensity signal measured by the receiving unit 130 is referred to as a background signal, and the corrected signal is calculated using the average value of the processed signal. can do.

When the first light is a visible light and the second light is infrared light, the control unit 140 determines whether the value obtained by subtracting the first wavelength correction from the second wavelength correction is equal to or greater than a predetermined reference, And if it is within the predetermined reference range from 0, it is possible to determine the main cause of the visibility decay as yellow dust and fog.

In addition, the integrated multi-wavelength remote visibility meter 100 may include a housing 150 housing the transmitter 110 and the receiver 130 together; As shown in FIG.

According to the present invention, it is possible to secure the merit as a remote tachometer, that is, the advantage that the correction can be calculated even on a relatively clear day, and at the same time, the configuration in which the transmitter and the receiver, which are disadvantages of the conventional remote tachometers, , Device configuration and installation simpler than the existing has a big advantage. As a result, the convenience of installation and operation is improved compared to the conventional one, thereby improving user convenience.

In addition, the visibility measuring instrument of the present invention has a great effect of being able to track what factors of visibility attenuation are performed by performing measurements using light having a plurality of wavelengths. Specifically, as is well known, the two main causes of visibility damping are ultrafine dust with a relatively small particle size, and dust and fog with a relatively large particle size. In the case of a conventional visibility measuring device, There was no standard to do. However, since the time constant measuring device of the present invention can perform measurements using light having a plurality of wavelengths and determine the factor of the correction by using the change of the light scattering coefficient for each wavelength, As shown in Fig.

FIG. 1 shows the tendency of the light scattering coefficient variation according to the wavelength in the ultraviolet dust and the yellow sand environment.
2 is a configuration diagram of the time constant measuring instrument of the present invention.
3 is a transmission optical system of the visibility measuring instrument of the present invention.
4 is a receiving optical system of the visibility measuring instrument of the present invention.
5 shows a signal change obtained by the receiver according to whether or not the transmitter light source is turned on.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an integrated multi-wavelength remote tachometer according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the tendency of the light scattering coefficient variation according to the wavelength in the ultraviolet dust and the yellow sand environment (Jinsang Jung, YJ Kim, KY Lee, MG-Cayetano, T. Batmunkh, J.-H. Koo, and J. Kim, 2010. Spectral optical properties of long-range transport. Asian Dust and Pollution Aerosols over Northeast Asia in 2007 and 2008, Atmospheric Chemistry and Physics, 10 (12), 5391-5408.). More specifically, Fig. 1 (A) shows the tendency of the light scattering coefficient change tendency according to the wavelength in the harsh environment caused by the high concentration ultrafine dust, Fig. 1 (B) shows the light scattering coefficient variation Respectively. Comparing FIGS. 1 (A) and 1 (B), it was confirmed that the light scattering coefficient decreases with increasing wavelength in the case of a thin film produced by a material having a relatively small particle diameter, and a relatively large diameter substance It can be confirmed that a similar number of light scattering coefficients are exhibited irrespective of the change in wavelength.

The present invention intends to propose a remote visibility measuring device capable of tracking the main causes of visibility attenuation by constructing a device for corrective measurement using multi-wavelengths by applying this principle. In addition, as described above, there is proposed a remote visibility measuring instrument with a new configuration, which can solve the problem that the conventional remote visibility measuring instrument is separated from the transmitter and the receiver to cause inconvenience in installation and operation.

2 schematically shows a configuration diagram of the time constant measuring instrument of the present invention. 2, the time constant measuring apparatus 100 of the present invention includes a transmitter 110, a reflector 120, a receiver 130, and a controller 140. 2, in the present invention, since the transmitter 110 and the receiver 130 are disposed at the same position without being separated from each other and are integrally connected to each other, . The time measuring instrument 100 of the present invention may further include a housing 150 that houses the transmitting unit 110 and the receiving unit 130 integrally connected together as shown in FIG. It is possible. First, each part of the visibility measuring instrument 100 of the present invention will be described with reference to FIG.

The transmission unit 110 includes a first light source L1 for emitting a first light having a first wavelength, a second light source L2 for emitting a second light having a second wavelength, And a transmission optical system for collecting and collimating the second light with parallel light. That is, the transmitting unit 110 is capable of irradiating a plurality of lights that can be distinguished according to wavelengths at a time. At this time, it is preferable that the first light is a visible light (that is, light having a center wavelength of 530 nm) and the second light is infrared (i.e., a light having a center wavelength of 850 nm). By using multi-wavelength light in this way, the main cause of the visible decay can be traced, which will be described in more detail below.

The reflector 120 reflects the light emitted from the transmitter 110. In the case of the conventional remote corrective measuring instrument, the transmission unit is installed at one position and the reception unit is installed at another remote position to perform corrective measurement. In the present invention, the transmitter 110 and the receiver 130 are installed at one location And the reflector 120 is installed at a different position far away to perform corrective measurement. In this case, the distance between the transmitting unit 110 and the receiving unit 130 and the reflecting mirror 120 can be appropriately adjusted according to the purpose. For example, it can be determined within 100m for bad visibility measurement such as fog, and 100m ~ 1000m for city clear visibility in relatively clear environment. Further, the reflector 120 is preferably a retro-reflector that reflects light in the same direction regardless of the angle at which the light enters.

The receiving unit 130 includes a receiving optical system for receiving the light reflected by the reflecting mirror 120, a third photodetector D3 for detecting the first light, and a fourth photodetector D4 for detecting the second light . That is, the receiving unit 130 can discriminate and detect the first light and the second light, which have been mixed and examined by the transmitting unit 110.

The controller 140 calculates the visibility of the first wavelength and the second wavelength using the intensity of the light irradiated by the transmitter 110 and the intensity of the light detected by the receiver 130. [ Also, the controller 140 may use the calculated correction values to determine a corrective decline factor.

Hereinafter, the configuration of each of the transmitting unit 110 and the receiving unit 130 and the principle of measuring the correction and determining the correction factor in the controller 140 will be described in more detail.

3 is an embodiment of a transmission optical system of the time constant measuring instrument of the present invention. The transmission optical system included in the transmission unit 110 may be configured to collect the first light and the second light emitted from the first light source L1 and the second light source L2 in the same direction so as to be parallel light, As shown in FIG. 3, includes a first beam splitter BS1 and a first telescope part T1. 3, a second beam splitter BS2 is provided to detect the light intensity of the first light and the second light emitted from the first light source L1 and the second light source L2, A first photodetector D1, a first filter BP1, a second photodetector D2, and a second filter BP2. If the light intensity of the first light source L1 and the second light source L2 is always constant, the transmission optical system may include the first beam splitter BS1 and the first telescope part BS1, (T1) may be included. However, since the light intensity may not be ideally maintained in practice, it is more preferable that the transmission optical system further includes remaining optical elements for detecting the light intensity.

The first beam splitter BS1 reflects a part of the first light emitted from the first light source L1 and transmits a part of the second light emitted from the second light source L2. As an example, when the first light is a visible light and the second light is infrared, the first beam splitter BS1 reflects 95% or more of first light (visible light) and transmits 5% or less of the first light (visible light) (That is, most of the first light is reflected and most of the second light is transmitted to the first beam splitter BS1) by 90% or more of light (infrared ray). 3, when the first light source L1, the second light source L2, and the first beam splitter BS1 are disposed, most of the reflected first light and the first transmitted light Can proceed in the same direction. That is, by the arrangement of the first beam splitter BS1, a part of the first light emitted and reflected by the first light source L1 and a part of the second light emitted and transmitted by the second light source L2 are emitted in the same direction . ≪ / RTI >

The first telescope unit (T1) collects the first light and the second light traveling through the first beam splitter (BS1) and emits parallel light. In FIG. 3, the first telescope unit T1 is shown as an optical system including lenses and pinholes, but the present invention is not limited thereto. That is, the first telescope unit T1 may be formed so as to collect the first light and the second light to convert the light into a parallel light, and may be formed in an optical system different from that of FIG.

The second beam splitter BS2 reflects the remaining part of the first light transmitted through the first beam splitter BS1 and transmits the remaining part of the second light reflected from the first beam splitter BS1 . As an example, the second beam splitter BS2 may have the same specifications as the example of the first beam splitter BS1, i.e., when the first light is a visible light and the second light is infrared, The beam splitter BS2 also reflects 95% or more of the first light (visible light) and transmits 5% or less of the first light (visible light), transmits 90% or more of the second light (infrared light) (BS2) so that most of the first light is reflected and most of the second light is transmitted).

The first photodetector D1 serves to detect the remaining part of the first light reflected by the second beam splitter BS2. According to the above example, the first light emitted from the first light source L1 is transmitted through the first beam splitter BS1 to be 5% of the initial light intensity, and reflected by the second beam splitter BS2 5% x 95% = 4.75% of the initial light intensity. At this time, the second light emitted from the second light source L2 is reflected by the second beam splitter BS1 to be 10% of the original light intensity, and the second beam splitter BS2 again reflects 10% x 10% = 1% of the initial light intensity. That is, 4.75% of the first light emitted from the first light source L1 and 1% of the second light emitted from the second light source L2 are incident on the first photodetector D1. The first filter BP1 is disposed on the optical path between the second beam splitter BS2 and the first photodetector D1 to discriminate only the first one of the beams.

The first filter (BP1) is configured to selectively transmit only a wavelength within a predetermined range with the first wavelength as a center wavelength. As an example, when the first light is visible light and the second light is infrared light, the first filter BP1 has the first wavelength, that is, 530 nm as the center wavelength, and the light in the wavelength range of 10 nm Only light in a wavelength range) can be transmitted. Therefore, only the first one of the lights coming into the first photodetector D1 passes through the first filter BP1. In the first photodetector D1, the first light source L1, It is possible to detect light having an optical intensity of 4.75% of the first light emitted from the light source.

The second photodetector D2 serves to detect the remaining part of the second light transmitted through the second beam splitter BS2. According to the previous example, the second light emitted from the second light source L2 is reflected by the second beam splitter BS1 to be 10% of the original light intensity, and the second beam splitter BS2 10% x 90% = 9% of the initial light intensity. At this time, the first light emitted from the first light source L1 is transmitted through the first beam splitter BS1 to be 5% of the initial light intensity, and the second beam splitter BS2 is again transmitted 5% x 5% = 0.25% of the initial light intensity. That is, 0.25% of the first light emitted from the first light source L1 and 9% of the second light emitted from the second light source L2 are incident on the second photodetector D2. The second filter BP2 is disposed on the optical path between the second beam splitter BS2 and the second photodetector D2 to distinguish only the second one of them.

The second filter (BP2) is configured to selectively transmit only a wavelength within a predetermined range with the second wavelength as a central wavelength. As an example, when the first light is visible light and the second light is infrared light, the second filter BP1 has the second wavelength, i.e., 850 nm as the central wavelength, and the light in the upper and lower 10 nm wavelength ranges (i.e., 840 to 860 nm Only light in a wavelength range) can be transmitted. Therefore, only the second light of the light entering the second photodetector D2 is transmitted through the second filter BP2. According to the above example, the second light detector L2, in the second photodetector D2, It is possible to detect light having the light intensity of 9% of the second light emitted from the light source.

4 is an embodiment of a receiving optical system of the time constant measuring instrument of the present invention. The receiving optical system included in the receiving unit 130 may receive the light reflected by the reflecting mirror 120 and transmit it to the third photodetector D3 and the fourth photodetector D4, A second beam splitter BS3, a third filter BP3, and a fourth filter BP4, as shown in FIG.

The second telescope part (T2) receives light reflected by the reflector (120). In FIG. 4, the second telescope part T2 is shown as an optical system in which light beams of various types are made in parallel and then converted into parallel light beams and transmitted to the third beam splitter BS3 However, the present invention is not limited thereto.

The third beam splitter BS3 reflects a part of the first light included in the light received by the second telescope part T2 and transmits the reflected light to the third photodetector D3 and the second telescope part T2 , And transmits the second light to the fourth photodetector D4. As an example, the third beam splitter BS3 may be of the same specification as the first beam splitter BS1 and the second beam splitter BS2, i.e. the first light is a visible light and the second When the light is infrared, the third beam splitter BS3 also reflects 95% or more of the first light (visible light) and transmits 5% or less of the first light (visible light) (I. E., Most of the first light is reflected by the third beam splitter BS3 and most of the second light is transmitted).

The third filter BP3 is disposed on the optical path between the third beam splitter BS3 and the third photodetector D3 and has a first wavelength as a center wavelength and selectively transmits only wavelengths within a predetermined range . In one example, when the first light is a visible light and the second light is infrared, the third filter BP3 may have the same specifications as the first filter BP1. That is, the third filter BP3 may be configured so that only the first wavelength, that is, 530 nm is the central wavelength, and only the light in the upper 10 nm wavelength range (that is, the 520-540 nm wavelength range) is transmitted. Accordingly, only the first one of the light entering the third photodetector D3 passes through the third filter BP3. According to the previous example, the third photodetector D3 reflects It is possible to detect light having an optical intensity of 95% of the first light.

The fourth filter BP4 is disposed on an optical path between the third beam splitter BS3 and the fourth photodetector D4 and has a second wavelength as a central wavelength and selectively transmits only a predetermined wavelength . As an example, when the first light is visible light and the second light is infrared light, the fourth filter BP4 may have the same specifications as the second filter BP2. That is, the fourth filter BP4 may be configured to transmit only the second wavelength (850 nm) as the central wavelength and only the light in the wavelength range of 10 nm to 10 nm (ie, the light in the wavelength range of 840 to 860 nm). Therefore, only the second light of the light entering the second photodetector D2 passes through the second filter BP2. According to the above example, in the second photodetector D2, It is possible to detect light having an optical intensity of 90% of the second light.

In the multi-wavelength remote visibility meter 100 of the present invention, the transmitter 110 transmits the first light and the second light to the reflector 120 through the above-described configurations, and the reflector 120 The receiving unit 130 receives the reflected light and differentially detects the first light and the second light.

The control unit 140 measures the intensity of the light emitted from the first light source L1 and the second light source L2 in the transmission unit 110 and reflects the light reflected from the reflector 120 in the reception unit 130. [ The light intensities of the first light and the second light which have been obtained are measured and the visibility is calculated for each of the first light and the second light using the following equation.

Here, the light extinction coefficient can be calculated according to Lambert beer's law by the following equation of light extinction coefficient of Koschmeider.

,

,

In the above equation, the correction coefficient I ₀ refers to the light intensity measured by the receiving unit 130 when there is no contaminant in the air, and is a constant value measured and determined in advance. The actual measured light intensity I refers to the light intensity measured by the receiver 130 at the time of measurement (i.e., at the time when the visibility is to be measured). The light distance is the sum of the distance from the transmitter 110 to the reflector 120 and the distance from the reflector 120 to the receiver 130.

If the light received by the receiver 130 is irradiated by the transmitter 110 and is only reflected by the reflector 120, it is ideal, but actually other light such as sunlight is mixed with the light. Therefore, in the present invention, the controller 140 turns on / off the light source to perform this operation.

More specifically, the control unit 140 causes the first light source L1 and the second light source L2 to be repeatedly turned on / off at predetermined intervals. The light intensity signal measured by the receiver 130 is referred to as an acquisition signal when the signal is ON and the light intensity signal measured by the receiver 130 is referred to as a background signal when the signal is turned off, Signal, the control unit 140 calculates the correction using the average value of the processing signals. FIG. 5 shows a signal change obtained by the receiver in accordance with whether the transmitter light source is on or off, and the acquired signal and the processed signal at the time of ON / OFF are clearly distinguished. In this way, it is possible to reliably remove a background signal such as a sun light, and to accurately calculate only the light reflected from the reflector 120, that is, the processed signal.

On the other hand, if the light intensity emitted from the first light source L1 and the second light source L2 of the transmission unit 110 is ideally kept constant, the transmission unit 110 transmits the first light source L1 ), The second light source (L2), the first beam splitter (BS1), and the first telescope part (T1). However, in the actual environment, the light intensity emitted from the first light source L1 and the second light source L2 may vary due to various factors, and an error occurs when correcting calculation is performed without knowing the change.

In order to avoid such a problem, optical elements for detecting the light intensity of the first light source L1 and the second light source L2, that is, the first optical detector D1 and the second optical detector L2, 2 photodetector D2 as shown in FIG. That is then stores the signal intensity obtained in the calibration coefficient (I ₀₎ of the first photodetector (D1) and the second light detector (D2) when calculating the original as a reference value, when the time constant calculated from the actual atmospheric environment, the It is first determined whether the signal intensity obtained by the first photodetector D1 and the second photodetector D2 is equal to a reference value. In the same case, the correction value may be calculated using the signal values received by the receiver 130 as described above. Or adjusts the intensity of the current applied to the first light source (L1) or the second light source (L2) so as to be equal to the reference value, and then, in this state, To calculate the visibility. By doing so, it is possible to originally exclude errors in the correction calculation caused by variations in the light source intensity.

Hereinafter, the principle of determining the corrective attenuation principal by using the correction calculated using the light having a plurality of wavelengths will be described.

As described above, the visibility measuring apparatus 100 of the present invention calculates visibility using light having a plurality of wavelengths that can be distinguished. As a representative example, the first light is visible light and the second light is infrared light. On the other hand, if the results of FIG. 1 are retrospectively observed, the number of light scattering tends to decrease as the wavelength increases in the case of a thin film formed by a material having a relatively small particle diameter. It is also known that a similar number of light scattering arrays occur regardless of the change in wavelength.

Considering the results shown in FIG. 1, the fact that the measured values are similar to each other using two lights having different wavelengths means that the light extinction coefficients in each case are similar to each other. Therefore, in this case, It can be inferred that there is a relatively large diameter material in the atmosphere like this dust. That is, in the present invention, the correction value (i.e., the second wavelength (i.e., the second wavelength) measured by infrared rays (the center wavelength 850 nm, the second light) measured by a visible light (center wavelength 530 nm, first light) (That is, if the difference between the two visibility values is sufficiently small), it is natural to deduce that the main cause of the visibility attenuation is yellow dust and mist.

That is, when the first light is visible light and the second light is infrared light, if the value obtained by subtracting the first wavelength correction from the second wavelength correction is within a predetermined reference range from 0 (that is, If the difference in value is small enough, the main cause of the visibility decay can be judged to be dust and mist.

On the other hand, as can be seen from the above corrective relationship, the correction value is inversely proportional to the value of the light extinction coefficient. It is also known that, when a material having a relatively small diameter exists in the atmosphere, the light scattering coefficient tends to decrease as the wavelength increases. Therefore, in the presence of a relatively small diameter material in the atmosphere, it can be inferred that the correction value tends to increase as the wavelength increases. That is, in the present invention, even if the correction value (i.e., the first wavelength correction value) measured with a visible light (central wavelength 530 nm, first light) is a correction value measured with an infrared ray (center wavelength 850 nm, (I.e., the difference between the two visibility values is sufficiently large), it is natural to deduce that the main cause of visibility damping is ultrafine dust.

That is, when the first light is a visible light, the second light is infrared light, and the value obtained by subtracting the first wavelength correction from the second wavelength correction is equal to or greater than a predetermined reference value (that is, If it is large enough, it can be done to judge the main cause of visibility decay as super fine dust.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It goes without saying that various modifications can be made.

100: Integrated Multi-Wavelength Remote Visibility Meter
110: transmitting unit 120: reflector
130: Receiver 140:
150: Housing

Claims (10)

A first light source emitting a first light having a center wavelength of a first wavelength, a second light source emitting a second light having a center wavelength of a second wavelength, a transmission optical system for collecting the first light and the second light, A transmitting unit including a transmitting unit and a receiving unit.
A reflector that reflects the light emitted from the transmitter;
A receiving unit integrally connected to the transmitting unit, the receiving unit including a receiving optical system for receiving the light reflected by the reflecting mirror, a third photodetector for detecting the first light, and a fourth photodetector for detecting the second light.
A controller for calculating a correction for each of the first wavelength and the second wavelength using the intensity of the light irradiated by the transmitter and the intensity of light detected by the receiver, and determining a corrective attenuation factor using the calculated correction values;
And,
Wherein the controller measures a light intensity emitted from the first light source and the second light source in the transmitter and measures an optical intensity of the first light and the second light reflected from the reflector in the receiver, And the second light are calculated using the following equations,
The first light is a visible light, the second light is infrared light, and the value obtained by subtracting the first wavelength correction from the second wavelength correction is greater than or equal to a predetermined reference, the main cause of the visibility decay is determined as ultrafine dust, And the main cause of the attenuation is judged to be yellow dust and fog if it is within the reference range.

(At this time,

,
Calibration factor (I ₀ ): The light intensity measured at the receiver when there is no contaminant in the air,
Actual Measured Light Intensity (I): The measured light intensity at the receiving portion during measurement,
Light distance: the sum of the distance from the transmitter to the reflector and the distance from the reflector to the receiver)
The method according to claim 1,
Wherein the first light is a visible light and the second light is an infrared light.
The optical transmission system according to claim 1,
A portion of the first light emitted from the first light source, a portion of the second light emitted from the second light source, and a portion of the first light reflected and emitted from the first light source, A first beam splitter disposed to direct a portion of the transmitted second light in the same direction;
A first telescope part collecting first light and second light traveling through the first beam splitter and irradiating the first light and the second light as parallel light;
And a plurality of multi-wavelength remote-visibility measuring apparatuses.
The optical transmission system according to claim 3,
A second beam splitter configured to reflect the remaining portion of the first light transmitted through the first beam splitter and to transmit the remaining portion of the second light reflected from the first beam splitter;
A first photodetector for detecting a remaining portion of the first light reflected by the second beam splitter;
A first filter disposed on an optical path between the second beam splitter and the first photodetector, the first filter having a first wavelength as a center wavelength and selectively transmitting only a wavelength within a predetermined range;
A second photodetector for detecting a remaining portion of the second light transmitted through the second beam splitter;
A second filter disposed on an optical path between the second beam splitter and the second photodetector, the second filter having a second wavelength as a center wavelength and selectively transmitting only a wavelength within a predetermined range;
Further comprising: a second multi-wavelength remote-visibility measuring device for measuring the distance between the first and second multi-wavelength remote visibility measuring devices.
The optical receiver according to claim 1,
A second telescope for receiving the light reflected from the reflector;
Reflects a part of the first light included in the light received by the second telescope part and transmits the part of the second light included in the light received by the second telescope part to the third light detector, A third beam splitter disposed to direct to the detector;
A third filter disposed on an optical path between the third beam splitter and the third photodetector, the third filter having a first wavelength as a center wavelength and selectively transmitting only a wavelength within a predetermined range;
A fourth filter disposed on an optical path between the third beam splitter and the fourth photodetector, the fourth filter having a second wavelength as a center wavelength and selectively transmitting only a wavelength within a predetermined range;
And a plurality of multi-wavelength remote-visibility measuring apparatuses.
The apparatus according to claim 1,
Characterized in that it is a retro-reflector.
delete The apparatus of claim 1,
Repeating ON / OFF of the first light source and the second light source at predetermined periods,
The light intensity signal measured by the receiving unit at the time of ON is called an acquisition signal,
The light intensity signal measured by the receiver is referred to as a background signal,
When the light intensity signal from which the background signal is removed from the acquired signal is referred to as a processing signal,
And the visibility is calculated using the average value of the processed signals.
delete The apparatus as claimed in claim 1, wherein the integrated multi-
A housing for housing the transmitter and the receiver together;
Further comprising: a second multi-wavelength remote-visibility measuring device for measuring the distance to the object;

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