===== Retrieval of NO2 for scenes including realistic clouds =====

==== Reflectance calculated for full domain (588x624 pixels) ==== 

[{{ :projects:3dcats:wp_200:les_cloud:reflectance_450nm_sza30_phi013_umu1.0_phi-102.png?800 |Simulated reflectance (same horizontal resolution as the cloud data, approx. 1.2x1.2km².)}}]

{{:projects:3dcats:wp_200:les_cloud:reflectance_sentinel3_b1.npy|Reflectance data in numpy format.}}

== Settings for reflectance simulation ==

  * REPTRAN channel sentinel3_slstr_b1
  * US standard atmosphere
  * SZA: 30°, SAA: 13°
  * Viewing direction: nadir
  * MODIS albedo data (600 nm)
  * clouds from ICON simulation (wc mie, ic baum_v36 ghm)
     *{{:projects:3dcats:wp_200:les_cloud:wc3d_full.dat.gz|Liquid water cloud data}}
     *{{:projects:3dcats:wp_200:les_cloud:ic3d_full.dat.gz|Ice water cloud data}}
     *{{:projects:3dcats:wp_200:les_cloud:lat.dat|Latitude grid}}
     *{{:projects:3dcats:wp_200:les_cloud:lon.dat|Longitude grid}}

==== Spectral reflectance and layer-AMF calculated for Sentinel-5 (98x104 pixels) ====

== Settings for reflectance simulation ==

  * Wavelength range: 400-500nm (0.2nm resolution)
  * Layer AMF calculated at 460nm
  * Molecular tau file provided by Huan: moltau_400_500_u76_EuropeNO2_v2.nc
  * SZA: 30°, SAA: 13°
  * Viewing direction: nadir
  * albedo: 0.05
  * clouds from ICON simulation (wc mie, ic baum_v36 ghm)

[{{ :projects:3dcats:wp_200:les_cloud:reflectance_full.png?800 |Simulated reflectance. The left side is simulated on the same horizontal resolution as the cloud data (approx. 1.2x1.2km²), the middle is for a pixel size of approx. 7x7 m². The right panel shows the standard deviation of the reflectance for 10^5 photons per pixel.}}]
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[{{ :projects:3dcats:wp_200:les_cloud:spectra_full.png?400 |Reflectance spectra for pixels indicated in figure above. The shaded areas show the standard deviation of the Monte Carlo results.}}]

[{{ :projects:3dcats:wp_200:les_cloud:box_amf_profiles_full.png?400 |Layer-AMFs for pixels indicated in figure above. The shaded areas show the standard deviation of the Monte Carlo results.}}]

{{:projects:3dcats:wp_200:les_cloud:les_test_case_full_domain.nc|MYSTIC results (spectral reflectance and box-AMFs at 460nm)}}

== Retrieval tests (from Huan (BIRA)) ===

[{{ :projects:3dcats:wp_200:les_cloud:o4_cf.png?400 |Effective cloud fraction derived from O2-O2 absorption band.}}]

[{{ :projects:3dcats:wp_200:les_cloud:o4_ch.png?400 |Cloud height derived from O2-O2 absorption band.}}]\\

[{{ :projects:3dcats:wp_200:les_cloud:no2_difference_1.png?400 |Relative difference between retrieved and true NO2 concentration.}}]

== Simulation for LEO, case 12 ==

{{:projects:3dcats:wp_200:les_cloud:results_leo_case12_nocloudmask.nc|Simulation for LEO, Case 12 without cloud mask.}}