Estimation of optimal wavelengths for atmospheric non-line-of-sight optical communication in the UV range of the spectrum in the daytime and at night for baseline distances from 50 m to 50 km

Description of files contained in the folder “Optical models of the atmosphere for wavelength from 200 to 400 nm” of the paper Tarasenkov M. V., Belov V. V., Poznakharev E. S. “Estimation of optimal wavelengths for atmospheric non-line-of-sight optical communication in the UV range of the spectrum in the daytime and at night for baseline distances from 50 m to 50 km”

In the folder, models of the atmosphere for the UV wavelength range are contained that were used in the paper. The organization of the folders is the following.

In folder “model 2a”, the models described in the paper as models 2a and near the surface corresponding to the meteorological range SM = 1 km are contained. Folder “model 2a” contains two folders “sun” and “moon”. In folder “sun”, models of the atmosphere for calculation of solar background radiation are contained, and in folder “moon”, models of the atmosphere for calculation of background radiation from the full Moon are contained. The files contained in folders differ by the centers of the spectral intervals. File “file_ext_1_1.txt” corresponds to the spectral interval centered at a wavelength of 390 nm and having a width of 10 nm. File “file_ext_1_2.txt” corresponds to the spectral interval centered at a wavelength of 380 nm and having a width of 10 nm, etc.

In folder “model 2b”, the models described in the article as model 2b and near the surface corresponding to the meteorological range SM = 10 km are contained. The organization of files in the folder is completely analogous to the organization of files in folder “model 2a”.

In folder “model 2с”, the models described in the article as model 2с and near the surface corresponding to the meteorological range SM = 20 km are contained. The organization of files in the folder is completely analogous to the organization of files in folder “model 2a”.

In folder “model 2d”, the models described in the article as model 2d and near the surface corresponding to the meteorological range SM = 50 km are contained. The organization of files in the folder is completely analogous to the organization of files in folder “model 2a”.

Files in folders have identical formats. We consider it on the example of file “model 2a\sun\file_ext_1_1.txt”.

3.900000E-001 is the center of the spectral range, in m. In this case, it is 0.39 μm.
 1.589300000000000E-001 is the solar constant (or the lunar constant in folder “moon”), in W/(cm2*μm*sr). In this case, the solar constant is 0.158 W/(cm2*μm*sr).
Then the values of the optical coefficients are given for 32 layers of the atmosphere.
Example:
   1 0.000000E+000 1.000000E-001 5.643120E+000 5.367254E+000 4.611581E-002 4.608071E-002, where “1” is the layer number; “0.000000E+000” is the altitude of the lower layer boundary, in km; “1.000000E-001” is the altitude of the upper layer boundary, in km; “5.643120E+000” is the aerosol extinction coefficient, in km–1; “5.367254E+000” is the aerosol scattering coefficient, in km-1; “4.611581E-002” is the molecular extinction coefficient, in km–1; “4.608071E-002” is the molecular scattering coefficient, in km-1.
Then 34 values of the scattering angle cosines μ are contained for which the aerosol scattering phase functions are tabulated.
For example:
 1.000000E+000 9.994000E-001, where “1.000000E+000” is the first cosine of the scattering angle, “9.994000E-001”is the second cosine of the scattering angle, etc.
Then the aerosol scattering phase functions ga are contained in line for each of 32 layers and 34 above-indicated scattering angle cosines.
Example:
   1 1.524900E+002 1.855000E+001, where “1” is the serial number of the atmospheric layer; “1.524900E+002” is the value of the aerosol scattering phase function for the first layer of the atmosphere and the scattering angle cosine equal to “1.000000E+000”; “1.855000E+001” is the value of the aerosol scattering phase function for the first layer of the atmosphere and the scattering angle cosine equal to “9.994000E-001”, etc.
Then for each of 32 layers, the values of integrals of the aerosol scattering phase functions in the limits from 1 to the corresponding cosine of the scattering angle are contained (only 34 values + 1 – the layer number).
Example:
   1 0.000000E+000 5.209500E-002 7.793000E-002, where “1” is the layer number; 0.000000E+000 – is the integral from 1 to 1 from ga(μ)dμ;
5.209500E-002 – is the integral from 9.994000E-001 to 1 from ga(μ)dμ;
7.793000E-002 - – is the integral from 9.976000E-001 to 1 from ga(μ)dμ

 
Description of files contained in the folder “SNR for day and night cases for UV range” of the paper Tarasenkov M. V., Belov V. V., Poznakharev E. S. “Estimation of optimal wavelengths for atmospheric non-line-of-sight optical communication in the UV range of the spectrum in the daytime and at night for baseline distances from 50 m to 50 km”

In the folder, results of calculations of the impulse responses (IPR) and of the signal-to-noise ratios (SNR) are contained. The singly scattered component of the impulse response h1 was calculated by the Monte Carlo method with local estimates, and the multiply scattered component of the impulse response hmsc was calculated by the Monte Carlo method with modified double local estimates. The impulse response was calculated from the formula: h(t) = h1(t) + hmsc(t). The signal-to-noise ratio was calculated from formula (25) of the paper. The organization of folders is the following.
In folder “variant 1”, the results are stored for the following optical-geometrical conditions: λ = 210–390 nm, atmospheric model 2b (SM = 10 km), θT = 85 deg, θR = 85 deg, YN = 0.05–50 km, and α = 0 deg. Values of the impulse response are stored in the folder “IPR”. The folder “IPR” contains folders “005”, “01”, “05”, “1”, “2”, “5”, “10”, “20”, “30”, “40”, and “50”. They correspond to the baseline distances YN = 0.05 km, YN = 0.1 km, etc. Inside each folder, files of two types are contained:
1) “h1_L210_model2b_YN005_alfa0.txt”,
2) “hmsc_L210_model2b_YN005_alfa0.txt”.
File “h1_L210_model2b_YN005_alfa0.txt” and analogous to it mean that results of calculations of the singly scattered component of the impulse response h1 are stored in it for the spectral region centered at λ = 210 nm having a width of 10 nm for the 2b atmosphere model, baseline distance YN =0.05 km, and α = 0 deg.
File “hmsc_L210_model2b_YN005_alfa0.txt” and analogous to it mean that results of calculations of     multiply scattered component of the impulse response hmsc are stored in it for the spectral interval centered at λ = 210 nm having a width of 10 nm for the 2b atmosphere model, baseline distance YN = 0.05 km, and α = 0 deg.
The format of files “h1 … txt” and “hmsc … txt” is the following:
  1 0.000000E+000 1.018299E-010 1.164003E-001 2.000000E-003, where “1” is the serial number of the time interval; “0.000000E+000” and “1.018299E-010” are the ends of the time intervals, in s; “1.164003E-001”is the h1 value for files “h1 … txt”, and hmsc are for files “hmsc … txt” averaged over the indicated time period, in 1/(m2s); and “2.000000E-003” is the estimate of the relative calculation error (in this case, an error is 0.2 %).

The values of the signal-to-noise ratio under conditions without background radiation (Pb = 0) are stored in folder “n”. The values of the signal-to-noise ratio under conditions of background radiation from the Sun at the zenith are stored in folder “d”. The values of the signal-to-noise ratio under conditions of background radiation from the full Moon at the zenith are stored in folder “m”. In folders “n”, “d”, and “m” the files are stored containing the SNR values and entitled like: “SNR_YN01_n_model2b_alfa0.txt”.
File “SNR_YN01_n_model2b_alfa0.txt” and the files analogous to it contain the results of SNR calculations for all spectral intervals considered in the work for the baseline distance YN = 0.1 km under conditions without background radiation “n” (if “d”, with solar background radiation, and if “m”, with lunar background radiation) for atmosphere model 2b and α = 0 deg.
In file “SNR_YN01_n_model2b_alfa0.txt” and files analogous to it, the data structure is the following:
3.900000E-001 10 8.500000E+001 8.500000E+001 1.000000E-001 0 3.455190E+005, where “3.900000E-001” is the wavelength of the center of the spectral interval, in μm; “10” is the meteorological range for the employed model of the atmosphere (10 km for model 2b, 20 km for model 2c, and 50 km for model 2d); “8.500000E+001” is the θT value (equal to 85 deg); “8.500000E+001” is the θR value (equal to 85 deg), “1.000000E-001” is the baseline distance YN (in this case, YN = 0.1 km), “0” is the value of the angle α (in this case, α = 0 deg), “3.455190E+005” is the SNR value for the considered optical-geometrical conditions.

Results are stored in folder “variant 2” for the following optical-geometrical conditions: λ = 210–390 nm, atmosphere model 2c (SM = 20 km), θT = 85 deg, θR = 85 deg, YN = 0.05–50 km, and α = 0 deg. The values of the impulse response are stored in folder “IPR”. The values of the signal-to-noise ratio under conditions without background radiation (Pb = 0) are stored in folder “n”. The values of the signal-to-noise ratio under conditions of background radiation from the Sun at the zenith are stored in folder “d”. The values of the signal-to-noise ratio under conditions of background radiation from the full Moon at the zenith are stored in folder “m”. The organization of folder content is completely analogous to folder “variant 1”.

Results are stored in folder “variant 3” for the following optical-geometrical conditions: λ = 210–390 nm, atmosphere model 2d (SM = 50 km), θT = 85 deg, θR = 85 deg, YN = 0.05–50 km, and α = 0 deg. The values of the impulse response are stored in folder “IPR”. The values of the signal-to-noise ratio under conditions without background radiation (Pb = 0) are stored in folder “n”. The values of the signal-to-noise ratio under conditions of background radiation from the Sun at the zenith are stored in folder “d”. The values of the signal-to-noise ratio under conditions of background radiation from the full Moon at the zenith are stored in folder “m”. The organization of folder content is completely analogous to folder “variant 1”.

Results are stored in folder “variant 4” for the following optical-geometrical conditions: λ = 210–390 nm, atmosphere model 2d (SM = 50 km), θT = 85 deg, θR = 85 deg, YN = 0.05–50 km, and α = 10 deg. The values of the impulse response are stored in folder “IPR”. The values of the signal-to-noise ratio under conditions without background radiation (Pb = 0) are stored in folder “n”. The values of the signal-to-noise ratio under conditions of background radiation from the Sun at the zenith are stored in folder “d”. The values of the signal-to-noise ratio under conditions of background radiation from the full Moon at the zenith are stored in folder “m”. The organization of folder content is completely analogous to folder “variant 1”.