KR101894406B1 - Linear Atmospheric Transmission Model Calculation Method - Google Patents

Abstract

The present invention relates to a method for calculating a linear atmospheric transmission model to calculate a horizontal atmospheric transmission. An objective of the present invention is to provide a method for calculating a linear atmospheric transmission model to calculate a horizontal atmospheric transmission, capable of accurately and exactly calculating the horizontal atmospheric transmission through a series of line-by-line calculations using data of a high resolution transmission molecular absorption database (HTRAN), such as absorption line strength, absorption line half width, and absorption coefficient, to be efficiently used not only for the study on a detailed atmospheric transmission for each wave but also for verifying and correcting a device of employing an average atmospheric transmission of mid and far infrared rays. Accordingly, in order to accomplish the above object, the present invention includes a model initial condition setting step, an absorption gas unit conversion step, a molecular absorption data input step, a gas absorption coefficient correction step, and a horizontal atmosphere transmission calculating step.

Description

{Linear Atmospheric Transmission Model Calculation Method for Calculation of Horizontal Air Transmittance}

The present invention relates to a method of calculating an atmospheric permeability model, and more particularly, to a method for calculating an atmospheric permeability model, and more particularly, to a method for calculating an atmospheric permeability model, Line-by-line calculation using absorption line strength, absorption line width, absorption coefficient, etc., to calculate more precise and accurate horizontal atmospheric transmittance, and to study the detailed atmospheric transmittance of each wave number, The present invention relates to a method of calculating a linear atmospheric permeability model for calculating a horizontal atmospheric permeability that can be utilized for calibration and calibration of an apparatus using an average atmospheric permeability.

Atmospheric permeability (rate) refers to the degree to which solar radiation is absorbed or reflected and partially attenuated during the passage of the earth's atmosphere, assuming that the sun is above the vertical line and dividing the solar radiation above the horizon by the solar constant .

In the atmospheric permeability, in particular, the horizontal atmospheric permeability refers to the ratio of the amount of energy that the energy caused by heat or light enters into the object and the amount of energy that is transmitted. Actual atmospheric permeability depends on the absorbed gas (H ₂ O, CO ₂ , O ₃ ), humidity, clouds, precipitation, aerosols, etc. and surface characteristics such as surface temperature and ground surface reflections (albedo) And also shows different characteristics depending on the transmitted optical path.

That is, there may be a difference depending on the vertical direction and the horizontal direction. This is closely related to the absorbed gas or cloud, and as the altitude increases vertically, the amount of absorbed gas becomes smaller. In the presence of clouds, the atmospheric permeability decreases sharply. Such atmospheric permeability is useful for analyzing the signal and radiation characteristics reaching the satellite and grasping the radiation amount, the cloud information, and the surface characteristics. It is also used to calibrate the solar radiation system used in remote sensing using quantified atmospheric permeability. It is also used to analyze the time, space and radiation balance of the solar irradiance used as renewable energy.

In particular, the horizontal air permeability is a very important parameter when measuring the temperature of an object from an infrared sensor. For example, when measuring the temperature of an object, the infrared signal emitted from the object reaches the observation device (sensor) and is attenuated by absorption by the atmosphere. Therefore, if such correction is not smoothly performed and the accuracy of the horizontal air permeability is lowered, there is a problem that the temperature of the measured object may be significantly different from the actual temperature.

Meanwhile, the infrared sensor is utilized in various fields such as military, medical, industrial, weather prediction, crime prevention, and fire safety. In such a variety of applications, first of all, as an example of military use, horizontal air permeability is used as a signal analysis method to detect enemy traps for the main purpose of detection of airborne infiltration through infrared signals, and the performance of UAV and surveillance system It has a big influence.

An example of a method for industrial and weather forecasting is to measure the visibility of the runway using horizontal atmospheric permeability information. In the medical industry, it is used to diagnose diseases by diagnosing the body temperature, Safety and so on.

As such, the horizontal atmospheric permeability is an important indicator variable affecting life and environment. Therefore, the calculation of horizontal atmospheric permeability using remote sensing can be very important because it can evaluate the potential of solar energy.

Korean Patent Registration No. 1404430 Korea Patent No. 1479702

Accordingly, the present invention is designed to enable more accurate and accurate horizontal air permeability calculation to be performed;

It is an object of the present invention to provide a method for calculating more precise and accurate horizontal air permeability through a series of line-by-line calculations using high resolution molecular absorption database (HITRAN) data such as absorption line strength, absorption line half width, It is possible to calculate the linear atmospheric permeability model for the calculation of the horizontal atmospheric permeability so that it can be effectively used for the calibration and correction of the apparatus using the mean air permeability in the middle infrared and far infrared region as well as for the study of the detailed atmospheric permeability by the wavenumber Method.

It is another object of the present invention to provide a method of calculating a horizontal atmospheric permeability by setting a horizontal distance and an absorption gas and inputting a range and an interval of an output wave number (or wavelength) It is possible to calculate the correct absorption coefficient by applying the Lorentz expansion which is the expansion of the absorption line near the surface and to obtain more precise and reliable horizontal atmospheric transmittance And a method for calculating a linear atmospheric permeability model for calculating a horizontal atmospheric permeability.

In order to accomplish the above object, there is provided a method for calculating a linear atmospheric permeability model for calculating a horizontal atmospheric permeability according to the present invention,

Select absorbing gas, the concentration of a selected gas, a wave number region, set interval, the horizontal distance, and, with the model the initial condition setting step of inputting a surface temperature and pressure, the unit (ppmv) of an input gas density units (gm ^{- 3} ), and an initial condition model includes an absorbing gas unit conversion step of converting the absorption coefficient of the gas into the absorption coefficient of the gas, the half-width of the absorption line, and the half-width of the absorption line according to wavenumbers among the data stored in the high-resolution molecular absorption database (HITRAN) A gas absorption coefficient correction for correcting the temperature and pressure information inputted in the model initial condition setting step by the Lorentz expansion application to the absorption line intensity by using the high resolution molecular absorption database (HITRAN) data, And a horizontal air permeability calculation step of calculating an average air permeability by the absorption coefficient calculated by the Lorentz expansion. It is achieved by.

As described above, the linear atmospheric permeability model calculation method for calculating the horizontal atmospheric permeability according to the present invention can be applied to a line-by-line calculation using high resolution molecular absorption database (HITRAN) data such as absorption line strength, absorption line half width, Can be used to calculate precise and accurate horizontal atmospheric permeability, which can be used not only for studying the detailed atmospheric permeability by wavenumber, but also for testing and calibrating devices using the mean air permeability in the mid-infrared and far-infrared regions Provide an effect to make.

According to another aspect of the present invention, there is provided a method of calculating a horizontal atmospheric permeability model for calculating a horizontal atmospheric transmittance, comprising the steps of: setting a horizontal distance and an absorbing gas; inputting an output wave number (or wavelength) Considering that the gas absorption coefficient can be changed according to the temperature and pressure in the calculation process, it is possible to perform correction according to temperature and pressure and to calculate the correct absorption coefficient by applying the Lorentz expansion, which is expansion of the absorption line near the surface This provides a very useful anticipatory effect, such as allowing accurate and reliable horizontal air permeability to be calculated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic flowchart showing the steps of calculating a linear atmospheric permeability model for calculating a horizontal air permeability according to the present invention;
FIG. 2 is a graph showing the horizontal atmospheric permeability per wavelength calculated by the present invention
FIG. 3 is a graph showing the horizontal atmospheric transmittance according to the horizontal distance calculated by the present invention

Hereinafter, preferred embodiments of the linear air permeability model calculation room for calculating the horizontal air permeability according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to the schematic schematic configuration of the present invention with reference to the accompanying drawings,

1, the model initial condition setting step S1, the absorption gas unit conversion step S2, the molecular absorption data input step S3, the gas absorption coefficient correction step S4, And a horizontal atmospheric permeability calculation step S5.

Here, the model initial condition setting step (S1) first selects the absorbed gas through the setting of the model initial conditions, and sets the concentration of the selected absorbent gas, the wavenumber (or wavelength) region, the set interval and the horizontal distance, And a process of inputting a temperature and an air pressure.

The absorbed gas unit conversion step S2 is a process of converting the units of the absorbed gas inputted through the model initial condition setting step S1 into density units gm ^-3 and inputting them. At this time, it is very important to determine the type of the absorption gas and the amount of gas in order to calculate the horizontal air permeability. For example, the amount of gas on the optical path varies depending on the horizontal distance, and the energy absorbed by the concentration of the input gas is increased, which has a great influence on the atmospheric permeability. Therefore, since the concentrations of the gases presently present have different units, they must be converted to density units (gm ^-3 ) that can be input to this model. However, since most gases are measured in units of density, and trace gases are not well representative of changes in quantity, they are expressed in relative ratios such as parts per million by volume (ppmv) . In the case of ozone (O ₃ ) concentration, it is preferable to use a Dobson unit (DU) or atm-cm unit to perform unit conversion by the following formula.

a) ppmv → gm ^-3

gm ^-3 = ppmv × (M / 22.4) × (273.15 / T _a ) × (P / 1013.25) × 10 ³ ... ... ... ... (One)

Where M is the gaseous molecular weight (g mole ^-1 ), T _a is the surface temperature (K), P is the surface pressure (hPa) and the constants 22.4 and 10 ³ are the gases at 0 ° C and 1 atm (273.12 K) (1013.25 hPa) It means a volume of 1 mole and a constant for unit conversion.

b) Humidity (kg kg ^-1 ) → gm ^-3

q = 0.622 x (e / P) ... ... ... ... ... ... ... ... ... ... ... ... (2)

e = (q x P) /0.622 ... ... ... ... ... ... ... ... ... ... ... ... (3)

ρ _v = 10 ⁹ x e / R _v x T ... ... ... ... ... ... ... ... ... ... ... ... (4)

Where e is the water vapor pressure (hPa), P is the surface pressure (hPa), R _v is the gas constant of water vapor ^{(461.5 J kg -1 K -1)} , T is the surface temperature (K), ρ _v is the water vapor density (gm ^-3 ) And 10 ⁹ is a constant for unit conversion it means.

c) di, atm-cm -> gm ^-3

6.424 × 10 ^-3 gm ^-3 = 300 dI = 0.3 atm-cm ... ... ... ... ... ... (5)

The molecular absorption data inputting step S3 is a step of inputting the molecular absorption data by converting the gas unit (ppmv) into the density unit (gm ^-3 ) through the absorption gas unit conversion step (S2) It is a process of inputting the absorption coefficient by gas and the half-width information of the absorption line among the data stored in the high resolution molecular absorption database (HITRAN). In general, the absorbed energy for each type of absorption gas and for the wavenumber is usually determined in the laboratory. However, it is almost impossible to measure the absorption energy of radiation for a single wave by an isolated gas molecule. Therefore, it is usual to experiment on a certain volume of gas, and in this case, the collision effect of gases and the moving speed effect of gases are included in the absorption line experiment, and the intensity of the absorption line including these effects is provided as an average value for a narrow interval wave number .

Thus, in the present invention, the absorbed gas data input to the linear air permeability model is HITRAN (High Resolution Transmission Molecular Absorption Database, Rothman et al., 2013) Cambridge Research Laboratory), and is currently undergoing the improvement and management of data at Harvard University. This is a high-resolution molecular absorption database that is a collection of spectral parameters and is composed of various computer codes, so that it can be used for detection of trace gases, weak absorption characteristics in the atmosphere, laser transmission studies, remote Exploration, and research on Lada. The latest edition of the HITRAN version of the 2012 edition includes 47 types of gases (7 major gases: H ₂ O, CO ₂ , O ₃ , N ₂ O, CO, CH ₄ , O ₂ , _{NO, SO 2, NO 2,} NH 3, HNO 3, OH, HF, HCI, HBr, HI, CIO, OCS, H 2 CO, HOCI, N 2, HCN, CH 3 CI, H 2 O 2, C 2 _{H 2, C 2 H 6,} PH 3, COF 2, SF 6, H 2 S, HCOOH, HO 2, O, CIONO 2, NO +, HOBr, C 2 H 4, CH 3 OH, CH 3 Br, CH 3 CN, CF ₄ , C ₄ H ₂ , HC ₃ N, H ₂ , CS, and SO ₃ ).

Therefore, the data input to the linear air permeability model of the present invention uses the absorption coefficient, the intensity of the absorption line, and the absorption curve of the absorption wave in the absorption gas among the high resolution molecular absorption database (HITRAN) data. That is, the strength of this model can calculate the horizontal atmospheric transmittance densely at each wavenumber interval set by the user using the HITRAN information. In addition, HITRAN data are data measured at the reference temperature (296 K) and 1 atmospheric pressure, so the atmospheric permeability is calculated by correcting the gas absorption coefficient for the surface temperature and atmospheric pressure.

In addition, the gas absorption coefficient correction step (S4) corrects the surface temperature and pressure information inputted in the model initial condition setting step by the above-described high resolution molecular absorption database (HITRAN) data by the Lorentz expansion application Process.

For example, if two gases with different wave numbers of internal energy cause an inelastic collision, they share some of the internal energy for the wave of the other. Therefore, if there are a number of collisions between gases, energy changes occur in other wave numbers besides the intrinsic wave energy absorbed by the gas. As a result, when any gas molecule or atom in the atmosphere absorbs radiation of a specific wave number, the internal energy change of the gas molecule causes some energy change to the surrounding wave number other than the specific wave number, which is called broadening of the absorption line. The expansion of the absorption line is natural broadening, collision broadening, and Doppler broadening. In the case of natural expansion, in the state of collision with other gas or in a state of not moving, even if the radiation is emitted after a certain period of time, a wave energy different from the wave number before absorption is generated, Extensions can be ignored compared to. In the case of expansion by the Doppler effect, a complex energy change of pure rotation energy or rotation / vibration occurs mainly in the upper atmosphere. In other words, it is desirable to apply the Lorentz expansion, which is an expansion due to collision, in order to calculate the horizontal atmospheric permeability in the troposphere where the amount of gas is large and the collision of gas is frequent.

   Therefore, when the gas absorbs the radiation of the intrinsic wave number, the intensity of the absorption line (S) is defined as follows:

………………………………… (6)

... ... ... ... ... ... ... ... ... ... ... ... ... (6)

는 파수간격

에 따른 기체 분자 및 원자의 질량 흡수 계수(단위cm² mole^{- 1})로서, 수식(7)과 같이 정의된다.here

Interval of wave number

(Unit: cm ² mole ^{- 1} ) of the gas molecules and atoms according to the equation (7).

…………………………………… (7)

... ... ... ... ... ... ... ... ... ... ... ... ... ... (7)

는 분자 충돌에 의한 파수,

는 중심 파수,

는 모양 요소이다. 이와 같은, 흡수선의 모양 요소는 수식(8)과 같이 계산될 수 있다.here

Is the wave number due to molecular collision,

Is the center frequency,

Is a shape element. Such a shape element of the absorption line can be calculated as shown in equation (8).

………………………… (8)

... ... ... ... ... ... ... ... ... ... (8)

은, 파수

에 대한 흡수계수의 절반이 되는 곳에서 로렌츠 확장까지의 파수 폭으로 반폭치 (half-width)를 의미한다. 이와 같은, 반폭치는 기압 (

)과 기온 (

)의 함수로써, 수식(9)와 같이 정리된다.here

, The wave number

The half-width is the wave width from the half of the absorption coefficient to the Lorentz expansion. Such a half-width value is the pressure

) And temperature (

), And is summarized as Equation (9).

……………………………… (9)

... ... ... ... ... ... ... ... ... ... ... ... (9)

과

은 각각 1013.25 hPa와 273.15 K로 표준 상태임을 의미한다. In the above equation (9)

and

Mean standard values of 1013.25 hPa and 273.15 K, respectively.

은 기체 분자의 모양이 선형이거나 분자가 tri-atomic일 경우에 따라 각각의 기체별로 1 혹은 1.5의 상수가 적용된다.

는 표준 상태에서의 반폭치로 지구대기 중의 복사 흡수 기체들에 대하여 약 0.01 cm^-1에서 0.1 cm^-1까지 변화한다. 이때 CO₂의 경우 흡수 계수의 변화가 크지 않기 때문에 0.07 cm^-1로 일정하게 설정된다. 이러한 로렌츠 확장 정리는 지표면으로부터 연직으로 약 20km 지점까지 적용될 수 있다.here,

Is a constant of 1 or 1.5 for each gas depending on whether the gas molecule is linear or tri-atomic.

Is a half-width in the standard state and varies from about 0.01 cm ^-1 to 0.1 cm ^-1 for radiation-absorbing gases in the Earth's atmosphere. In this case, since the variation of the absorption coefficient is not large for CO ₂ , it is set to 0.07 cm ^-1 constantly. This Lorentz expansion theorem can be applied from the surface to about 20 km vertically.

)에 기체의 밀도 (

) 그리고 수평 거리(

)가 곱해져 설정된 파수 (혹은 파장) 영역에 대하여 적분 간격별 (수식 (10)) 그리고 영역 적분 후 평균된 수식 (11) 대기투과도가 산출된다.Finally, the horizontal air permeability calculation step S5 is a process of calculating the average air permeability by the absorption coefficient calculated by the above-described gas absorption coefficient correction step S4, for example, the Lorentz expansion. The calculation of the horizontal atmospheric permeability can be performed using the absorption coefficients calculated in the Lorentz expansion as shown in Equations (10) and (11)

) To the density of the gas

) And horizontal distance (

(10)) and (11) averaged permeability is calculated for the wavenumber (or wavelength) region set by multiplying the wavenumber (wavenumber) by the integration interval.

………………………………… (10)

... ... ... ... ... ... ... ... ... ... ... ... ... (10)

………………… (11)

... ... ... ... ... ... ... (11)

와

는 파수별 수평 대기투과도와 영역 평균된 수평 대기투과도 그리고

과

는 사용자가 선택한 파수 영역의 시작과 끝 파수를 의미한다.Where exp is an exponential function,

Wow

The horizontal atmospheric permeability, the area-averaged horizontal atmospheric permeability,

and

Means the beginning and ending wave numbers of the wave range selected by the user.

As described above, the linear air permeability model calculation method for calculating the horizontal atmospheric permeability according to the present invention is characterized in that the information of the absorbed gas (absorption line strength, absorption line width, absorbency) of the detailed wave number of the high resolution molecular absorption database (HITRAN) Coefficient) to calculate precise and accurate horizontal atmospheric permeability through a line-by-line calculation. At this time, the input to the model is to select the absorber gas, the density of the gas, the area and interval of the wave (or wavelength) to be calculated, and enter the horizontal distance, the surface temperature and the air pressure. The calculated horizontal atmospheric permeability can be used to calculate the average atmospheric permeability for both the wavenumber and for the entire region and to investigate the detailed atmospheric permeability by wave number or to use the mean atmospheric permeability of the far infrared and far infrared region have.

The results obtained by applying the horizontal air permeability according to the present invention are shown in FIGS. 2 and 3. Here, FIG. 2 shows the horizontal atmospheric permeability when the concentration is different for a fixed horizontal distance (1 km) with respect to H ₂ O, CO ₂ and O ₃ classified as main gas in the atmosphere. The horizontal atmospheric permeability was calculated by changing the CO ₂ to 360, 380, 400 ppmv and the O ₃ to 250, 300, and 350 DU for 2, 5, and 10 gm ^-3 for H ₂ O. At this time, the surface temperature and the pressure set is 300 K and 1013 hPa, and each integration interval there was shown to average a 1 cm ^-1 when exposed to the illustration, but set to 0.01 cm ^-1. From these results, it can be seen that as the concentration increases, the horizontal atmospheric permeability decreases, and each result is calculated for each set wavenumber interval and the average horizontal atmospheric permeability for the whole area is calculated.

FIG. 3 also shows the change in horizontal atmospheric permeability along the distance by inputting both H ₂ O, CO ₂ and O ₃ gases. The concentration of each gas was 5 gm ^-3 , 380 ppmv and 300 DU, respectively, and the horizontal distance was reduced to 1, 0.5, and 0.2 km. As a result, horizontal air permeability increased as the horizontal distance decreased. That is, the shorter the optical path is, the lower the concentration of the absorbed gas in the optical path is, and the higher the atmospheric transmittance is.

S1: Model initial condition setting step
S2: absorption gas unit conversion step
S3: step of inputting molecular absorption data
S4: gas absorption coefficient correction step
S5: Horizontal air permeability calculation step

Claims (4)

A model initial condition setting step (S1) for selecting an absorbing gas, inputting concentration, wavenumber range, setting interval, horizontal distance, and surface air temperature and air pressure of the selected gas;
Model the initial condition unit of the gas inputted through the setting step (S1) (ppmv, kg · kg -1, atm-cm, DU) the density units (gm ^-3) to the absorption unit the gas conversion step of converting input (S2 );
An absorption gas unit conversion step (S2) for inputting the converted absorption gas;
In the initial condition model, the gas unit was converted into the density unit (gm ^-3 ) and the absorption coefficient of the gas according to the wavenumbers, the absorption line strength, the half width of the absorption line (half) of the data stored in the high resolution molecular absorption database (HITRAN) (step S3) of inputting molecular weight absorption data;
(S4) a gas absorption coefficient correction step (S4) of correcting the temperature and pressure information inputted in the model initial condition setting step by data in the high resolution molecular absorption database (HITRAN) by the Lorentz expansion application to the absorption line intensity;
And a horizontal air permeability calculation step (S5) of calculating the average air permeability by the absorption coefficient calculated by the Lorentz expansion in the step of correcting the gas absorption coefficient. The linear air permeability model calculation method for calculating the horizontal air permeability .
The method of claim 1, further comprising:
In the absorption gas unit conversion step (S2), a conversion formula for converting the units of gas (ppmv, kg · kg ^-1 , atm-cm, DU) into density units (gm ^-3 ) is:
a) ppmv → gm ^-3
gm ^-3 = ppmv × (M / 22.4) × (273.15 / T _a ) × (P / 1013.25) × 10 ³ ... ... ... ... (One)
Where M is the gaseous molecular weight (g mole ^-1 ), T _a is the surface temperature (K), P is the surface pressure (hPa) and the constants 22.4 and 10 ³ are at 0 ° C (273.15 K) and 1 atmospheric pressure (1013.25 hPa) Constant for volume and unit conversion of 1 mole of gas.
b) Humidity (kg kg ^-1 ) → gm ^-3
q = 0.622 x (e / P) ... ... ... ... ... ... ... ... ... ... ... ... (2)
e = (q x P) /0.622 ... ... ... ... ... ... ... ... ... ... ... ... (3)
ρ _v = 10 ⁹ x e / R _v x T _a ... ... ... ... ... ... ... ... ... ... ... ... (4)
Where e is the water vapor pressure (hPa), P is the surface pressure (hPa), R _v is the gas constant of water vapor (461.5 J kg ^-1 K ^-1), T is _a surface temperature (K), ρ _v is the water vapor density (gm ^{- 3} ) and 10 ⁹ are constants for unit conversion.
c) di, atm-cm -> gm ^-3
6.424 × 10 ^-3 gm ^-3 = 300 dI = 0.3 atm-cm ... ... ... ... ... ... (5)
And calculating a horizontal atmospheric permeability model for calculating the horizontal atmospheric permeability.
The method of claim 1, further comprising:
In the gas absorption coefficient correction step (S4), the equation for calculating the absorption line strength S by applying Lorentz expansion to the inputted temperature and pressure information is:

... ... ... ... ... ... ... ... ... ... ... ... ... (6)
here

Interval of wave number

The mass absorption coefficient (in cm ² mole ^-1 )

... ... ... ... ... ... ... ... ... ... ... ... ... ... (7)
here

Is the wave number due to molecular collision,

Is the center frequency,

Is a shape element, and the shape element of the absorption line is;

... ... ... ... ... ... ... ... ... ... (8)
here

Wave number

Is the half-width of the wave width from the half of the absorption coefficient to the expansion of the Lorentz, and the half-width is the air pressure

) And temperature (

As a function of

... ... ... ... ... ... ... ... ... ... ... ... (9)
And in this equation,

Wow

Is a standard state at 1013.25 hPa and 273.15 K, respectively, for calculating the horizontal atmospheric permeability model.
The method of claim 1, further comprising:
The atmospheric permeability calculation equation through the horizontal air permeability calculation step (S5)

... ... ... ... ... ... ... ... ... ... ... ... ... (10)

... ... ... ... ... ... ... ... (11)
Here, exp is an exponential function,

The horizontal atmospheric permeability,

Is the area-averaged horizontal atmospheric permeability, and

and

Is a wavenumber at the beginning and end of the wavenumber region selected by the user.

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