RTTOV v13 Coefficient File Downloads
RTTOV Coefficient File Downloads
- 1 RTTOV v13 Coefficient File Downloads
- 2 Choosing which coefficients to use
- 3 RTTOV v12 compatibility
- 4 Hi-res UV/VIS/IR sounder coefficients and optical properties
- 5 UV/visible/IR coefficients and optical properties
- 6 MW optical depth coefs and RTTOV-SCATT optical properties
- 7 Information on visible/IR cloud/aerosol files
- 8 Reference profiles and regression limits
Important notes:
- The NWP SAF only endorses and supports the use of coefficients that are generated by the NWP SAF team. We do not guarantee the quality of any coefficient files obtained from any source other than this website or directly from the NWP SAF team.
- Please submit requests for new coefficients to the help desk. New coefficients are provided on a best efforts basis given resource availability. Requests for sensors with immediate application in NWP are given highest priority, followed by those with a broad user interest for research purposes. Lowest priority is given to those which are very specific or experimental, and to any requests which require that we do not share the resulting coefficients on the website.
- The following sensor coefficient files were generated with Copernicus funding:
– NOAA 5-14 MSU, DMSP 8-15 SSM/I, Nimbus 7 SMMR, DMSP 11-15 SSM/T-2, DMSP 16-19 SSMI/S, Nimbus 5-6 ESMR, Nimbus-5 NEMS, Nimbus-6 SCAMS, DMSP 7-15 SSM/T
– Meteor 25 SI, Nimbus-4 IRIS, DMSP 1-4 SSH
The rttov_coef_download.sh script supplied in the RTTOV package in the rtcoef_rttov13/ directory can be used for downloading coefficient files in bulk or you can download individual files from the links below. You only need to download coefficients for the simulations you wish to carry out.
Update history for this page.
Additional information about coefficient files.
Spectral response functions and passbands used when generating the latest optical depth coefficient files.
Plots/tables comparing RTTOV with line-by-line (LBL) data for each optical depth coefficient file.
Choosing which coefficients to use
There are very many gas optical depth coefficient (rtcoef) files to choose from. Here we provide recommendations depending on your application.
If using RTTOV v13:
- default recommendation for MW sensors: v13 predictors (based on measured SRFs where available, “_srf” files, and with variable O3 where available, “_o3” files)
- default recommendation for UV/VIS/IR: v13 predictors with variable O3+CO2 (“_o3co2” files)
- if additional trace gases required for UV/VIS/IR: v13 predictors with all trace gases (“_7gas” files)
- if speed is critical and variable gases are not relevant for UV/VIS/IR: v13 predictors with variable O3 (“_o3” files)
If using RTTOV v12 or earlier:
- MW sensors: v7 predictors (based on measured SRFs where available, “_srf” files)
- non-solar IR simulations for sensors in low Earth orbit or GEO sensors simulating satellite zenith angles only below ~65 degrees: v7 predictors
- if solar radiation required, or additional trace gases, or GEO sensors in general: v9 predictors
Nimbus-6 PMR and NOAA SSU coefficients are special cases and only available with v8 predictors (compatible with RTTOV v12 and v13).
Where there is a choice between 54L and 101L: choose 101L unless speed is critical.
RTTOV v12 compatibility
- New v13 predictor coefficient files are NOT compatible with RTTOV v12. Coefficients based on the new predictors are available for most sensors. These are the recommended optical depth coefficients for RTTOV v13. If you can’t find the file(s) you’re looking for below, you can request new coefficient files via the helpdesk.
- All RTTOV v12-compatible rtcoef files can be used directly with RTTOV v13. Coefficient files trained with LBLRTM v12.8 and based on the old v7/8/9 predictors are available for most sensors: these can be used with RTTOV v12 and v13.
- RTTOV v12 sccldcoef/scaercoef files do not work with RTTOV v13: new files for most sensors are available below (these cannot be used with v12). The cloud liquid water optical properties have been updated for v13 using a newer refractive index dataset.
- New MFASIS LUT files have been generated for v13 based on the updated cloud liquid water properties: these include Rayleigh multiple scattering and improved flagging of out-of-bounds simulation geometry. The new files can be used with RTTOV v12, but note the caveats given below. The existing v12 MFASIS LUTs can also be used with v13, but the new files are strongly recommended in preference.
- For RTTOV-SCATT, new hydrotables (v13 only) replace the old “Mietable” files (v12 and earlier only). The new files have updated optical properties.
- RTTOV v12 PC-RTTOV coefficients files work with RTTOV v13.
Download pre-existing RTTOV v12 coefficients (v7/8/9 predictor VIS/IR coefficients based on LBLRTM v12.2 and v7 predictor MW coefficients) here.
Hi-res UV/VIS/IR sounder coefficients and optical properties
Optical depth coefs and cloud/aerosol optical properties
General information on hi-res IR sounder optical depth coefficient files:
- Based on LBLRTM v12.8 line-by-line model
- Based on v13 predictors
- Coefficients on 101L with variable O3+CO2 available for all sensors
- Coefficients on 54L and 101L with variable O3-only available for selected sensors (others on request)
- Coefficients on 101L with all variable trace gases available for selected sensors (others on request)
- Solar-enabled for channels below 5 microns
- Coefficients for GEO sensors support the full range of zenith angles covered by RTTOV (up to ~85 degrees)
- No Planck-weighted channels
- For UV simulations RTTOV v13.1 and later are recommended
Downloads
- All files are linked in the table below.
- Due to the large size of the hi-res sounder files HDF5 is the preferred format for them. Please contact the NWP SAF Helpdesk to request an ASCII version of a file if required. See here for notes on converting between coefficient file formats (ASCII, binary, HDF5) and extracting subsets of channels from coefficient files.
- The same cloud and aerosol coefficient files are used with all optical depth coefficient files (including the old RTTOV v12-compatible rtcoef files).
- The chou-only cloud/aerosol files are recommended if you only want to use Chou-scaling for IR scattering simulations (no DOM, no solar) as the files are much smaller than the full ones.
- Download to folders as follows:
- v13 predictor 101L rtcoef files – download to rtcoef_rttov13/rttov13pred101L/
- v13 predictor 54L rtcoef files – download to rtcoef_rttov13/rttov13pred54L/
- All cloud/aerosol files – download to rtcoef_rttov13/cldaer_visir/
See below for information about cloud and aerosol optical property files.
Metop-B/C IASI coefficients, NOAA-20/21 CrIS coefficients: the same coefficient files for a given hyperspectral sensor (including optical depth coefficients, cloud/aerosol properties, and PC coefficient files) can be used for that sensor on all satellite platforms. Therefore the IASI coefficient files for Metop-A can be used for Metop-B/C, and the CrIS NSR and FSR files for S-NPP (JPSS-0) can be used for NOAA-20/21.
*Nimbus-4 IRIS “shifted” coefficients: nominal central wavenumbers are divided by 0.9995. This factor is mentioned in the literature (see the first paragraph under Methods on the last page).
Nimbus-4 IRIS “C3S” coefficients were generated for the Copernicus Climate Change Service: more information is given in the headers which can be displayed using the rttov_coef_info.exe tool which is compiled to the bin/ directory as part of the RTTOV build.
**MTG-IRS coefficients: these have been generated using the latest channel specification which has different spectral resolutions in the long and short wave bands (hence “2mopd” in the filename to distinguish them from earlier files). The “hamming” files are based on Hamming-apodised transmittances, and are recommended for use with RTTOV. The “atbd” files are generated using the “light apodisation” function described in the ATBD, 16 March 2018, integral of a Gaussian centred on “gate”, reference: MTG-IRS level 1 ATBD, EUM/RSP/TEN/16/878765, V1E draft 7 June 2017. Due to this light apodisation, the errors in the RTTOV optical depth prediction scheme are larger than for other sensors, particularly in the short-wave band. For example see the this page for the LBL vs RTTOV statistics for the RTTOV v13 predictor 101L variable O3+CO2 coefficients (more information about these plots is available on the LBL/RTTOV comparison page, with links to plots for all available MTG-IRS coefficients).
***GIIRS coefficients: these are Hamming apodised (a=0.23, 0.8cm MPD) with a spectral resolution of 0.625 cm-1. They cover the range of channels supported by each instrument, but in practice the distributed data may contain fewer channels (especially for FY-4A) and after apodisation you may optionally choose to remove one or two channels at either end of each band. In that case, you may wish to extract a subset of channels using the rttov_conv_coef.exe executable (see Annex A in the user guide) so that the coefficient file includes only the channels you require. The FY-4A/B files contain the following channels (note that FY-4A contains a subset of the channels in the FY-4B file):
– FY-4A GIIRS, 1682 channels:
721 channels in LW band 680-1130cm-1
961 channels in MW band 1650-2250cm-1
– FY-4B GIIRS 1690 channels:
725 channels in LW band 678.75-1131.25 cm-1
965 channels in MW band 1648.75-2251.25 cm-1
PC-RTTOV coefficients
Currently PC-RTTOV coefficients are available for a subset of hyperspectral IR sounders. It is important to use the same optical depth (rtcoef) coefficient file in the simulation as was used for training the PC coefficients. These files have “pcrttov_compat” in the filename and are linked in the table below: these are currently all based on LBLRTM v12.2 and have not changed since RTTOV v12. The optical depth coefficient files are all based on v9 predictors with all trace gases excluding SO2 and are on 101 levels.
The latest PC coefficients allow all optional RTTOV variable gases (except SO2). In addition PC coefficients are available which allow for aerosol simulations using the OPAC aerosol optical properties. See the user guide for more information on this and see below for information on the PC regression limits for trace gases and aerosols.
The optical depth and PC coefficient files currently available are linked in the table below. The table also indicates what kind of simulations each set of PC coefficients is compatible with and this is also indicated in the pccoef filename:
- sea => only trained for sea profiles: set calcemis(:) to TRUE
- landsea => trained over all surface types: it is recommended to set calcemis(:) to TRUE over sea and to set calcemis(:) to FALSE over land and use the UW IR emissivity atlas to obtain land surface emissivity values (though this is not strictly mandatory)
- nlte => can optionally be used with the RTTOV NLTE bias correction
- trace => additional trace gases are optionally variable: O3, CO2, N2O, CO, CH4
- aer => simulations can optionally include OPAC aerosols
See below for information on the gas and aerosol regression limits for PC-RTTOV.
The predictor channel selection is unique for each PC coefficient file and can be obtained in your own code using the rttov_get_pc_predictindex subroutine as demonstrated in src/test/example_pc_fwd.F90.
Downloads
- All files are linked in the table below.
- Due to the large size of the hi-res sounder files HDF5 is the preferred format for them. Please contact the NWP SAF Helpdesk to request an ASCII version of a file if required. See here for notes on converting between coefficient file formats and extracting subsets of channels from coefficient files.
- Download to folders as follows:
- PC-RTTOV-compatible v9 predictor 101L rtcoef files – download to rtcoef_rttov13/rttov9pred101L/
- PC-RTTOV pccoef files – download to rtcoef_rttov13/pc/
- OPAC Aerosol optical property scaercoef files – download to rtcoef_rttov13/cldaer_visir/
| Sensor | Trace gases for PC | NLTE for PC? | Aerosols for PC? | Surface types for PC | Optical depth coef filename | Date of rtcoef file creation | PC coef filename | Associated OPAC aerosol coef filename |
|---|---|---|---|---|---|---|---|---|
| AIRS | O3 | N | N | land, sea | rtcoef_eos_2_airs_pcrttov_compat.H5 | 01/02/2014 | pccoef_eos_2_airs_landsea.H5 | - |
| IASI | O3, CO2, N2O, CO, CH4 | Y | N | land, sea | rtcoef_metop_2_iasi_pcrttov_compat.H5 | 02/09/2016 | pccoef_metop_2_iasi_landsea_trace_nlte.H5 | - |
| IASI | O3, CO2, N2O, CO, CH4 | N | Y | land, sea | As above | 02/09/2016 | pccoef_metop_2_iasi_landsea_trace_aer.H5 | scaercoef_metop_2_iasi_opac_chou-only.H5 |
| IASI-NG | O3 | N | N | sea-only | rtcoef_metopsg_1_iasing_pcrttov_compat.H5 | 01/02/2014 | pccoef_metopsg_1_iasing_sea.H5 | - |
The Metop-2 (Metop-A) IASI files above can also be used for Metop-B and -C.
HTFRTC coefficients
There is a bug in HTFRTC in RTTOV v13 which means it cannot be used. HTFRTC coefficients will not be made available until the bug is fixed.
LBLRTM v12.8 RTTOV v7/8/9 predictor hyperspectral sounder coefficients
Various v7, v8 and v9 predictor hi-res IR sounder coefficients are available based on LBLRTM v12.8. These files can be used with RTTOV v12. If using RTTOV v13 we would encourage you to use the v13 predictor files above in preference to these. See the v13 predictor coefficients table above for links to the cloud/aerosol optical property files for these sensors, and see the notes below the v13 predictor table above for more information about the IRIS, GIIRS, MTG-IRS, IASI and CrIS coefficients.
| Sensor | Levels | Predictors version | Trace gases | Solar? | NLTE? | Filename | Date of file creation |
|---|---|---|---|---|---|---|---|
| AIRS | 54 | 7 | O3 | N | Y | rtcoef_eos_2_airs.H5 | 11/07/2024 |
| AIRS | 101 | 7 | O3 | N | Y | rtcoef_eos_2_airs.H5 | 11/07/2024 |
| AIRS | 101 | 8 | O3, CO2 | N | Y | rtcoef_eos_2_airs.H5 | 11/07/2024 |
| AIRS | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | Y | rtcoef_eos_2_airs_7gas.H5 | 11/07/2024 |
| AIRS L1C | 54 | 7 | O3 | N | N | rtcoef_eos_2_airs_l1c.H5 | 24/04/2024 |
| AIRS L1C | 101 | 7 | O3 | N | N | rtcoef_eos_2_airs_l1c.H5 | 24/04/2024 |
| AIRS L1C | 101 | 8 | O3, CO2 | N | N | rtcoef_eos_2_airs_l1c.H5 | 23/04/2024 |
| AIRS L1C | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | N | rtcoef_eos_2_airs_l1c_7gas.H5 | 30/05/2024 |
| CrIS NSR | 54 | 7 | O3 | N | Y | rtcoef_jpss_0_cris.H5 | 26/10/2020 |
| CrIS NSR | 101 | 7 | O3 | N | Y | rtcoef_jpss_0_cris.H5 | 26/10/2020 |
| CrIS NSR | 101 | 8 | O3, CO2 | N | Y | rtcoef_jpss_0_cris.H5 | 26/10/2020 |
| CrIS NSR | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | Y | rtcoef_jpss_0_cris_7gas.H5 | 14/09/2020 |
| CrIS FSR | 54 | 7 | O3 | N | Y | rtcoef_jpss_0_cris-fsr.H5 | 27/10/2020 |
| CrIS FSR | 101 | 7 | O3 | N | Y | rtcoef_jpss_0_cris-fsr.H5 | 26/10/2020 |
| CrIS FSR | 101 | 8 | O3, CO2 | N | Y | rtcoef_jpss_0_cris-fsr.H5 | 26/10/2020 |
| CrIS FSR | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | Y | rtcoef_jpss_0_cris-fsr_7gas.H5 | 29/10/2020 |
| FORUM | 101 | 7 | O3 | N | N | rtcoef_forum_1_forum.H5 | 11/03/2021 |
| FORUM | 101 | 8 | O3, CO2 | N | N | rtcoef_forum_1_forum.H5 | 11/03/2021 |
| FORUM | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | N | N | rtcoef_forum_1_forum_7gas.H5 | 11/03/2021 |
| GIIRS | 54 | 7 | O3 | N | N | rtcoef_fy4_1_giirs.H5 | 27/10/2020 |
| GIIRS | 101 | 7 | O3 | N | N | rtcoef_fy4_1_giirs.H5 | 27/10/2020 |
| GIIRS | 101 | 8 | O3, CO2 | N | N | rtcoef_fy4_1_giirs.H5 | 27/10/2020 |
| GIIRS | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | N | rtcoef_fy4_1_giirs_7gas.H5 | 02/11/2020 |
| GIIRS-2 | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | N | rtcoef_fy4_2_giirs_7gas.H5 | 29/11/2023 |
| HIRAS NSR | 54 | 7 | O3 | N | N | rtcoef_fy3_4_hiras.H5 | 27/10/2020 |
| HIRAS NSR | 101 | 7 | O3 | N | N | rtcoef_fy3_4_hiras.H5 | 27/10/2020 |
| HIRAS NSR | 101 | 8 | O3, CO2 | N | N | rtcoef_fy3_4_hiras.H5 | 29/10/2020 |
| HIRAS NSR | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | N | rtcoef_fy3_4_hiras_7gas.H5 | 03/11/2020 |
| HIRAS FSR | 54 | 7 | O3 | N | N | rtcoef_fy3_4_hirasfsr.H5 | 27/10/2020 |
| HIRAS FSR | 101 | 7 | O3 | N | N | rtcoef_fy3_4_hirasfsr.H5 | 27/10/2020 |
| HIRAS FSR | 101 | 8 | O3, CO2 | N | N | rtcoef_fy3_4_hirasfsr.H5 | 29/10/2020 |
| HIRAS FSR | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | N | rtcoef_fy3_4_hirasfsr_7gas.H5 | 02/11/2020 |
| HIRAS-2 | 54 | 7 | O3 | N | N | rtcoef_fy3_5_hiras2.H5 | 20/01/2023 |
| HIRAS-2 | 101 | 7 | O3 | N | N | rtcoef_fy3_5_hiras2.H5 | 20/01/2023 |
| HIRAS-2 | 101 | 8 | O3, CO2 | N | N | rtcoef_fy3_5_hiras2.H5 | 20/01/2023 |
| HIRAS-2 | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | N | rtcoef_fy3_5_hiras2_7gas.H5 | 20/01/2023 |
| IASI | 54 | 7 | O3 | N | Y | rtcoef_metop_2_iasi.H5 | 11/07/2024 |
| IASI | 101 | 7 | O3 | N | Y | rtcoef_metop_2_iasi.H5 | 11/07/2024 |
| IASI | 101 | 8 | O3, CO2 | N | Y | rtcoef_metop_2_iasi.H5 | 11/07/2024 |
| IASI | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | Y | rtcoef_metop_2_iasi_7gas.H5 | 11/07/2024 |
| IASI-NG | 54 | 7 | O3 | N | N | rtcoef_metopsg_1_iasing.H5 | 29/10/2020 |
| IASI-NG | 101 | 7 | O3 | N | N | rtcoef_metopsg_1_iasing.H5 | 26/10/2020 |
| IASI-NG | 101 | 8 | O3, CO2 | N | N | rtcoef_metopsg_1_iasing.H5 | 26/10/2020 |
| IASI-NG | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | N | rtcoef_metopsg_1_iasing_7gas.H5 | 29/10/2020 |
| IKFS2 | 101 | 7 | O3 | N | N | rtcoef_meteor-m_2_ikfs2.H5 | 11/03/2021 |
| IKFS2 | 101 | 8 | O3, CO2 | N | N | rtcoef_meteor-m_2_ikfs2.H5 | 11/03/2021 |
| IKFS2 | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | N | rtcoef_meteor-m_2_ikfs2_7gas.H5 | 11/03/2021 |
| IRIS | 101 | 13 | O3, CO2 | N | N | rtcoef_nimbus_4_iris.H5 | 27/10/2020 |
| IRIS "shifted"* | 101 | 13 | O3, CO2 | N | N | rtcoef_nimbus_4_iris-shifted.H5 | 29/10/2020 |
| IRIS "C3S"* | 101 | 13 | O3, CO2 | N | N | rtcoef_nimbus_4_iris-c3s.H5 | 09/03/2021 |
| MTG-IRS Hamming apodised** | 101 | 7 | O3 | N | Y | In preparation | 21/08/2024 |
| MTG-IRS Hamming apodised** | 101 | 8 | O3, CO2 | N | Y | In preparation | 21/08/2024 |
| MTG-IRS Hamming apodised** | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | Y | In preparation | 21/08/2024 |
| MTG-IRS lightly apodised** | 101 | 7 | O3 | N | N | In preparation | 19/08/2024 |
| MTG-IRS lightly apodised** | 101 | 8 | O3, CO2 | N | N | In preparation | 20/08/2024 |
| MTG-IRS lightly apodised** | 101 | 9 | O3, CO2, N2O, CO, CH4, SO2 | Y | N | In preparation | 14/08/2024 |
| MRFIRS | 54 | 7 | O3 | N | N | rtcoef_clarreo_1_mrfirs.H5 | 30/10/2020 |
| MRFIRS | 54 | 8 | O3, CO2 | N | N | rtcoef_clarreo_1_mrfirs.H5 | 30/10/2020 |
| SI | 101 | 8 | O3, CO2 | N | N | rtcoef_meteor_25_si.H5 | 26/10/2020 |
UV/visible/IR coefficients and optical properties
UV/VIS/IR optical depth coefs and cloud/aerosol optical properties
General information on visible/IR optical depth coefficient files:
- Based on LBLRTM v12.8 line-by-line model
- Based on v13 predictors
- Based on 54 levels
- Coefficients with variable O3+CO2 for all sensors
- Coefficients with variable O3-only for selected sensors (others on request)
- Coefficients with all supported variable gases (“7gas”) for selected sensors (others on request)
- Solar-enabled for channels below 5 microns: all files support all channels for which we have spectral response data
- Coefficients for GEO sensors support the full range of zenith angles covered by RTTOV (up to ~85 degrees)
- Not NLTE compatible
- Not PC compatible
- For UV simulations RTTOV v13.1 and later are recommended
NB Currently SSU, PMR coefficients are not available using v13 predictors: the RTTOV v12 files based on v8 predictors can be used with RTTOV v13. These can be downloaded below.
The CO2 concentration used to generate the variable O3-only files is contemporary (~400ppm) so for simulations of historical atmospheric profiles the variable O3+CO2 files are preferable as they allow you to specify a more appropriate CO2 profile.
Downloads
- See below if you require a coefficient file containing only the IR channels instead of all VIS+IR channels.
- 54L v13 predictor variable O3+CO2 files for all supported visible/IR sensors – extract to rtcoef_rttov13/rttov13pred54L/
- 54L v13 predictor variable O3 files for selected visible/IR sensors – extract to rtcoef_rttov13/rttov13pred54L/
- 54L v13 predictor 7gas files for selected visible/IR sensors – extract to rtcoef_rttov13/rttov13pred54L/
- Cloud scattering property files for all sensors – extract to rtcoef_rttov13/cldaer_visir/
- OPAC aerosol scattering property files for all sensors – extract to rtcoef_rttov13/cldaer_visir/
- CAMS aerosol scattering property files for all sensors – extract to rtcoef_rttov13/cldaer_visir/
See below for information about cloud and aerosol optical property files.
| Sensor | Trace gases | Filename | Date of file creation | Associated cloud coef filename | Associated OPAC aerosol coef filename | Associated CAMS aerosol coef filename |
|---|---|---|---|---|---|---|
| (A)ATSR* | O3, CO2 | rtcoef_ers_x_atsr_o3co2.dat rtcoef_envisat_1_atsr_o3co2.dat | 16/10/2020 | sccldcoef_ers_x_atsr.dat sccldcoef_envisat_1_atsr.dat | scaercoef_ers_x_atsr_opac.dat scaercoef_envisat_1_atsr_opac.dat | scaercoef_ers_x_atsr_cams.dat scaercoef_envisat_1_atsr_cams.dat |
| (A)ATSR* | O3 | rtcoef_ers_x_atsr_o3.dat | 16/10/2020 | sccldcoef_ers_x_atsr.dat | scaercoef_ers_x_atsr_opac.dat | scaercoef_ers_x_atsr_cams.dat |
| AATSR-shifted Info on AATSR 12 um anomaly | O3, CO2 | rtcoef_envisat_1_atsr-shifted_o3co2.dat | 16/10/2020 | sccldcoef_envisat_1_atsr-shifted.dat | scaercoef_envisat_1_atsr-shifted_opac.dat | scaercoef_envisat_1_atsr-shifted_cams.dat |
| AATSR-shifted Info on AATSR 12 um anomaly | O3 | rtcoef_envisat_1_atsr-shifted_o3.dat | 16/10/2020 | As above | As above | As above |
| ABI | O3, CO2 | rtcoef_goes_xx_abi_o3co2.dat | 16/10/2020 | sccldcoef_goes_xx_abi.dat | scaercoef_goes_xx_abi_opac.dat | scaercoef_goes_xx_abi_cams.dat |
| ABI | O3 | rtcoef_goes_xx_abi_o3.dat | 16/10/2020 | As above | As above | As above |
| ABI | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_goes_xx_abi_7gas.dat | 24/09/2020 25/09/2020 | As above | As above | As above |
| AGRI | O3, CO2 | rtcoef_fy4_x_agri_o3co2.dat | 16/10/2020 01/09/2022 | sccldcoef_fy4_x_agri.dat | scaercoef_fy4_x_agri_opac.dat | scaercoef_fy4_x_agri_cams.dat |
| AGRI | O3 | rtcoef_fy4_x_agri_o3.dat | 16/10/2020 01/09/2022 | As above | As above | As above |
| AGRI | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_fy4_x_agri_7gas.dat | 27/09/2024 01/09/2022 | As above | As above | As above |
| AHI | O3, CO2 | rtcoef_himawari_x_ahi_o3co2.dat | 16/10/2020 | sccldcoef_himawari_x_ahi.dat | scaercoef_himawari_x_ahi_opac.dat | scaercoef_himawari_x_ahi_cams.dat |
| AHI | O3 | rtcoef_himawari_x_ahi_o3.dat | 16/10/2020 | As above | As above | As above |
| AHI | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_himawari_x_ahi_7gas.dat | 24/09/2020 | As above | As above | As above |
| AMI | O3, CO2 | rtcoef_gkompsat2_1_ami_o3co2.dat | 03/05/2021 | sccldcoef_gkompsat2_1_ami.dat | scaercoef_gkompsat2_1_ami_opac.dat | scaercoef_gkompsat2_1_ami_cams.dat |
| AMI | O3 | rtcoef_gkompsat2_1_ami_o3.dat | 29/04/2021 | As above | As above | As above |
| AMI | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_gkompsat2_1_ami_7gas.dat | 03/05/2021 | As above | As above | As above |
| ASTER | O3, CO2 | rtcoef_eos_1_aster_o3co2.dat | 16/10/2020 | sccldcoef_eos_1_aster.dat | scaercoef_eos_1_aster_opac.dat | scaercoef_eos_1_aster_cams.dat |
| ASTER | O3 | rtcoef_eos_1_aster_o3.dat | 16/10/2020 | As above | As above | As above |
| AVHRR | O3, CO2 | rtcoef_noaa_xx_avhrr_o3co2.dat rtcoef_metop_x_avhrr_o3co2.dat | 16/10/2020 | sccldcoef_noaa_xx_avhrr.dat sccldcoef_metop_x_avhrr.dat | scaercoef_noaa_xx_avhrr_opac.dat scaercoef_metop_x_avhrr_opac.dat | scaercoef_noaa_xx_avhrr_cams.dat scaercoef_metop_x_avhrr_cams.dat |
| AVHRR | O3 | rtcoef_noaa_xx_avhrr_o3.dat rtcoef_metop_x_avhrr_o3.dat | 16/10/2020 | As above | As above | As above |
| CLIM | O3, CO2 | rtcoef_co2m_1_clim_o3co2.dat | 19/06/2023 | sccldcoef_co2m_1_clim.dat | scaercoef_co2m_1_clim_opac.dat | scaercoef_co2m_1_clim_cams.dat |
| CLIM | O3 | rtcoef_co2m_1_clim_o3.dat | 19/06/2023 | As above | As above | As above |
| CLIM | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_co2m_1_clim_7gas.dat | 19/06/2023 | As above | As above | As above |
| ECOSTRESS | O3, CO2 | rtcoef_iss_1_ecostres_o3co2.dat | 28/10/2020 | sccldcoef_iss_1_ecostres.dat | scaercoef_iss_1_ecostres_opac.dat | scaercoef_iss_1_ecostres_cams.dat |
| EOIR | O3, CO2 | rtcoef_micro2c_1_eoir_o3co2.dat | 25/10/2024 | - | - | - |
| EOIR | O3 | rtcoef_micro2c_1_eoir_o3.dat | 25/10/2024 | - | - | - |
| EOIR | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_micro2c_1_eoir_7gas.dat | 26/10/2024 | - | - | - |
| EPIC | O3, CO2 | rtcoef_dscovr_1_epic_o3co2.dat | 30/10/2020 | sccldcoef_dscovr_1_epic.dat | scaercoef_dscovr_1_epic_opac.dat | scaercoef_dscovr_1_epic_cams.dat |
| EPIC | O3 | rtcoef_dscovr_1_epic_o3.dat | 30/10/2020 | As above | As above | As above |
| FCI | O3, CO2 | rtcoef_mtg_1_fci_o3co2.dat | 13/05/2022 | sccldcoef_mtg_1_fci.dat | scaercoef_mtg_1_fci_opac.dat | scaercoef_mtg_1_fci_cams.dat |
| FCI | O3 | rtcoef_mtg_1_fci_o3.dat | 13/05/2022 | As above | As above | As above |
| FCI | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_mtg_1_fci_7gas.dat | 13/05/2022 | As above | As above | As above |
| GMS imager | O3, CO2 | rtcoef_gms_x_imager_o3co2.dat | 16/10/2020 | sccldcoef_gms_x_imager.dat | scaercoef_gms_x_imager_opac.dat | scaercoef_gms_x_imager_cams.dat |
| GOES imager | O3, CO2 | rtcoef_goes_xx_imager_o3co2.dat | 16/10/2020 | sccldcoef_goes_xx_imager.dat | scaercoef_goes_xx_imager_opac.dat | scaercoef_goes_xx_imager_cams.dat |
| GOES imager | O3 | rtcoef_goes_xx_imager_o3.dat | 16/10/2020 | As above | As above | As above |
| GOES sounder | O3, CO2 | rtcoef_goes_xx_sounder_o3co2.dat | 16/10/2020 | sccldcoef_goes_xx_sounder.dat | scaercoef_goes_xx_sounder_opac.dat | scaercoef_goes_xx_sounder_cams.dat |
| GOES sounder | O3 | rtcoef_goes_xx_sounder_o3.dat | 16/10/2020 | As above | As above | As above |
| HIRS | O3, CO2 | rtcoef_noaa_xx_hirs_o3co2.dat rtcoef_metop_x_hirs_o3co2.dat rtcoef_nimbus_6_hirs_o3co2.dat | 16/10/2020 | sccldcoef_noaa_xx_hirs.dat sccldcoef_metop_x_hirs.dat sccldcoef_nimbus_6_hirs.dat | scaercoef_noaa_xx_hirs_opac.dat scaercoef_metop_x_hirs_opac.dat scaercoef_nimbus_6_hirs_opac.dat | scaercoef_noaa_xx_hirs_cams.dat scaercoef_metop_x_hirs_cams.dat scaercoef_nimbus_6_hirs_cams.dat |
| HIRS | O3 | rtcoef_noaa_xx_hirs_o3.dat rtcoef_metop_x_hirs_o3.dat | 16/10/2020 | As above | As above | As above |
| HIRS shifted spectral response | O3, CO2 | rtcoef_noaa_xx_hirs-shifted_o3co2.dat rtcoef_metop_x_hirs-shifted_o3co2.dat | 16/10/2020 | sccldcoef_noaa_xx_hirs-shifted.dat sccldcoef_metop_x_hirs-shifted.dat | scaercoef_noaa_xx_hirs-shifted_opac.dat scaercoef_metop_x_hirs-shifted_opac.dat | scaercoef_noaa_xx_hirs-shifted_cams.dat scaercoef_metop_x_hirs-shifted_cams.dat |
| HIRS shifted spectral response | O3 | rtcoef_noaa_xx_hirs-shifted_o3.dat rtcoef_metop_x_hirs-shifted_o3.dat | 16/10/2020 | sccldcoef_noaa_xx_hirs-shifted.dat sccldcoef_metop_x_hirs-shifted.dat | scaercoef_noaa_xx_hirs-shifted_opac.dat scaercoef_metop_x_hirs-shifted_opac.dat | scaercoef_noaa_xx_hirs-shifted_cams.dat scaercoef_metop_x_hirs-shifted_cams.dat |
| HRIR | O3, CO2 | rtcoef_nimbus_x_hrir_o3co2.dat | 16/10/2020 | sccldcoef_nimbus_x_hrir.dat | scaercoef_nimbus_x_hrir_opac.dat | scaercoef_nimbus_x_hrir_cams.dat |
| IIR | O3, CO2 | rtcoef_calipso_1_iir_o3co2.dat | 16/10/2020 | sccldcoef_calipso_1_iir.dat | scaercoef_calipso_1_iir_opac.dat | scaercoef_calipso_1_iir_cams.dat |
| IIR | O3 | rtcoef_calipso_1_iir_o3.dat | 16/10/2020 | As above | As above | As above |
| INSAT-3D(R/S) imager | O3, CO2 | rtcoef_insat3_x_imager_o3co2.dat | 16/10/2020 15/09/2023 | sccldcoef_insat3_x_imager.dat | scaercoef_insat3_x_imager_opac.dat | scaercoef_insat3_x_imager_cams.dat |
| INSAT-3D(R/S) imager | O3 | rtcoef_insat3_x_imager_o3.dat | 16/10/2020 15/09/2023 | As above | As above | As above |
| INSAT-3D(R/S) sounder | O3, CO2 | rtcoef_insat3_x_sounder_o3co2.dat | 16/10/2020 19/01/2024 | sccldcoef_insat3_x_sounder.dat | scaercoef_insat3_x_sounder_opac.dat | scaercoef_insat3_x_sounder_cams.dat |
| INSAT-3D(R/S) sounder | O3 | rtcoef_insat3_x_sounder_o3.dat | 16/10/2020 22/01/2024 | As above | As above | As above |
| IRAS | O3, CO2 | rtcoef_fy3_1_iras_o3co2.dat | 16/10/2020 | sccldcoef_fy3_1_iras.dat | scaercoef_fy3_1_iras_opac.dat | scaercoef_fy3_1_iras_cams.dat |
| IRMSS | O3, CO2 | rtcoef_hj1_2_irmss_o3co2.dat | 27/10/2020 | sccldcoef_hj1_2_irmss.dat | scaercoef_hj1_2_irmss_opac.dat | scaercoef_hj1_2_irmss_cams.dat |
| LI** | O3, CO2 | rtcoef_mtg_1_li_o3co2.dat | 16/10/2020 | - | - | - |
| LI** | O3 | rtcoef_mtg_1_li_o3.dat | 16/10/2020 | - | - | - |
| MBFIRI | O3, CO2 | rtcoef_ticfire_1_mbfiri_o3co2.dat | 16/10/2020 | sccldcoef_ticfire_1_mbfiri.dat | scaercoef_ticfire_1_mbfiri_opac.dat | scaercoef_ticfire_1_mbfiri_cams.dat |
| MBFIRI | O3 | rtcoef_ticfire_1_mbfiri_o3.dat | 16/10/2020 | As above | As above | As above |
| MERSI-1 | O3, CO2 | rtcoef_fy3_3_mersi1_o3co2.dat | 27/10/2020 | sccldcoef_fy3_3_mersi1.dat | scaercoef_fy3_3_mersi1_opac.dat | scaercoef_fy3_3_mersi1_cams.dat |
| MERSI-2 | O3, CO2 | rtcoef_fy3_4_mersi2_o3co2.dat | 16/10/2020 | sccldcoef_fy3_4_mersi2.dat | scaercoef_fy3_4_mersi2_opac.dat | scaercoef_fy3_4_mersi2_cams.dat |
| MERSI-2 | O3 | rtcoef_fy3_4_mersi2_o3.dat | 16/10/2020 | As above | As above | As above |
| MERSI-LL | O3, CO2 | rtcoef_fy3_5_mersill_o3co2.dat | 08/02/2022 | sccldcoef_fy3_5_mersill.dat | scaercoef_fy3_5_mersill_opac.dat | scaercoef_fy3_5_mersill_cams.dat |
| MERSI-LL | O3 | rtcoef_fy3_5_mersill_o3.dat | 08/02/2022 | As above | As above | As above |
| MERSI-LL | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_fy3_5_mersill_7gas.dat | 08/02/2022 | As above | As above | As above |
| MERSI-3 | O3, CO2 | rtcoef_fy3_6_mersi3_o3co2.dat | 18/01/2024 | sccldcoef_fy3_6_mersi3.dat | scaercoef_fy3_6_mersi3_opac.dat | scaercoef_fy3_6_mersi3_cams.dat |
| MERSI-3 | O3 | rtcoef_fy3_6_mersi3_o3.dat | 18/01/2024 | As above | As above | As above |
| MERSI-RM | O3, CO2 | rtcoef_fy3_7_mersirm_o3co2.dat | 22/01/2024 | sccldcoef_fy3_7_mersirm.dat | scaercoef_fy3_7_mersirm_opac.dat | scaercoef_fy3_7_mersirm_cams.dat |
| MERSI-RM | O3 | rtcoef_fy3_7_mersirm_o3.dat | 22/01/2024 | As above | As above | As above |
| MERSI-RM | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_fy3_7_mersirm_7gas.dat | 23/01/2024 | As above | As above | As above |
| MetImage | O3, CO2 | rtcoef_metopsg_1_metimage_o3co2.dat | 16/10/2020 | sccldcoef_metopsg_1_metimage.dat | scaercoef_metopsg_1_metimage_opac.dat | scaercoef_metopsg_1_metimage_cams.dat |
| MetImage | O3 | rtcoef_metopsg_1_metimage_o3.dat | 16/10/2020 | As above | As above | As above |
| MI | O3, CO2 | rtcoef_coms_1_mi_o3co2.dat | 16/10/2020 | sccldcoef_coms_1_mi.dat | scaercoef_coms_1_mi_opac.dat | scaercoef_coms_1_mi_cams.dat |
| MI | O3 | rtcoef_coms_1_mi_o3.dat | 16/10/2020 | As above | As above | As above |
| MODIS | O3, CO2 | rtcoef_eos_x_modis_o3co2.dat | 16/10/2020 | sccldcoef_eos_x_modis.dat | scaercoef_eos_x_modis_opac.dat | scaercoef_eos_x_modis_cams.dat |
| MODIS | O3 | rtcoef_eos_x_modis_o3.dat | 16/10/2020 | As above | As above | As above |
| MODIS shifted spectral response | O3, CO2 | rtcoef_eos_x_modis-shifted_o3co2.dat | 16/10/2020 | sccldcoef_eos_x_modis-shifted.dat | scaercoef_eos_x_modis-shifted_opac.dat | scaercoef_eos_x_modis-shifted_cams.dat |
| MODIS shifted spectral response | O3 | rtcoef_eos_x_modis-shifted_o3.dat | 16/10/2020 | As above | As above | As above |
| MODIS shifted spectral response | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_eos_x_modis-shifted_7gas.dat | 25/09/2020 | As above | As above | As above |
| MRIR | O3, CO2 | rtcoef_nimbus_x_mrir_o3co2.dat | 16/10/2020 | sccldcoef_nimbus_x_mrir.dat | scaercoef_nimbus_x_mrir_opac.dat | scaercoef_nimbus_x_mrir_cams.dat |
| Earth-CARE MSI | O3, CO2 | rtcoef_earthcare_1_msi_o3co2.dat | 06/05/2022 | sccldcoef_earthcare_1_msi.dat | scaercoef_earthcare_1_msi_opac.dat | scaercoef_earthcare_1_msi_cams.dat |
| Earth-CARE MSI | O3 | rtcoef_earthcare_1_msi_o3.dat | 06/05/2022 | As above | As above | As above |
| Earth-CARE MSI | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_earthcare_1_msi_7gas.dat | 10/05/2022 | As above | As above | As above |
| Sentinel-2 MSI | O3, CO2 | rtcoef_sentinel2_x_msi_o3co2.dat | 16/10/2020 | sccldcoef_sentinel2_x_msi.dat | scaercoef_sentinel2_x_msi_opac.dat | scaercoef_sentinel2_x_msi_cams.dat |
| Sentinel-2 MSI | O3 | rtcoef_sentinel2_x_msi_o3.dat | 16/10/2020 | As above | As above | As above |
| MSUGS | O3, CO2 | rtcoef_electro-l_2_msugs_o3co2.dat | 16/10/2020 | sccldcoef_electro-l_2_msugs.dat | scaercoef_electro-l_2_msugs_opac.dat | scaercoef_electro-l_2_msugs_cams.dat |
| MSUGS | O3 | rtcoef_electro-l_2_msugs_o3.dat | 16/10/2020 | As above | As above | As above |
| MSUMR | O3, CO2 | rtcoef_meteor-m_x_msumr_o3co2.dat | 16/10/2020 | sccldcoef_meteor-m_x_msumr.dat | scaercoef_meteor-m_x_msumr_opac.dat | scaercoef_meteor-m_x_msumr_cams.dat |
| MSUMR | O3 | rtcoef_meteor-m_x_msumr_o3.dat | 16/10/2020 | As above | As above | As above |
| MTSAT imager | O3, CO2 | rtcoef_mtsat_x_imager_o3co2.dat | 29/10/2020 16/10/2020 | sccldcoef_mtsat_x_imager.dat | scaercoef_mtsat_x_imager_opac.dat | scaercoef_mtsat_x_imager_cams.dat |
| MVIRI (IR channels only) | O3, CO2 | rtcoef_meteosat_x_mviri_o3co2.dat | 16/10/2020 | sccldcoef_meteosat_x_mviri.dat | scaercoef_meteosat_x_mviri_opac.dat | scaercoef_meteosat_x_mviri_cams.dat |
| MVIRI-VIS**** | O3, CO2 | rtcoef_meteosat_x_mviri-vis_o3co2.dat | 31/05/2021 01/06/2021 02/06/2021 27/05/2021 | - | - | - |
| MVISR | O3, CO2 | rtcoef_fy1_x_mvisr_o3co2.dat | 16/10/2020 | sccldcoef_fy1_x_mvisr.dat | scaercoef_fy1_x_mvisr_opac.dat | scaercoef_fy1_x_mvisr_cams.dat |
| OLCI*** | O3, CO2 | rtcoef_sentinel3_x_olci_o3co2.dat | 16/10/2020 | sccldcoef_sentinel3_1_olci.dat sccldcoef_sentinel3_2_olci.dat | - | - |
| OLCI*** | O3 | rtcoef_sentinel3_x_olci_o3.dat | 16/10/2020 | As above | - | - |
| OLI | O3, CO2 | rtcoef_landsat_x_oli_o3co2.dat | 16/10/2020 23/06/2023 | sccldcoef_landsat_x_oli.dat | scaercoef_landsat_x_oli_opac.dat | scaercoef_landsat_x_oli_cams.dat |
| OLI | O3 | rtcoef_landsat_x_oli_o3.dat | 16/10/2020 23/06/2023 | As above | As above | As above |
| OLI | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_landsat_9_oli_7gas.dat | 23/06/2023 | As above | As above | As above |
| SBG | O3, CO2 | rtcoef_sbg_1_sbg_o3co2.dat | 22/10/2024 | - | - | - |
| SBG | O3 | rtcoef_sbg_1_sbg_o3.dat | 23/10/2024 | - | - | - |
| SBG | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_sbg_1_sbg_7gas.dat | 23/10/2024 | - | - | - |
| SEVIRI | O3, CO2 | rtcoef_msg_x_seviri_o3co2.dat | 16/10/2020 | sccldcoef_msg_x_seviri.dat | scaercoef_msg_x_seviri_opac.dat | scaercoef_msg_x_seviri_cams.dat |
| SEVIRI | O3 | rtcoef_msg_x_seviri_o3.dat | 16/10/2020 | As above | As above | As above |
| SEVIRI | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_msg_x_seviri_7gas.dat | 24/09/2020 | As above | As above | As above |
| SGLI | O3, CO2 | rtcoef_gcom-c_1_sgli_o3co2.dat | 16/10/2020 | sccldcoef_gcom-c_1_sgli.dat | scaercoef_gcom-c_1_sgli_opac.dat | scaercoef_gcom-c_1_sgli_cams.dat |
| SGLI | O3 | rtcoef_gcom-c_1_sgli_o3.dat | 16/10/2020 | As above | As above | As above |
| SIRS / SIRS-BLUR | O3, CO2 | rtcoef_nimbus_x_sirs_o3co2.dat rtcoef_nimbus_x_sirs-blur_o3co2.dat | 16/10/2020 | sccldcoef_nimbus_x_sirs.dat (same file for sirs-blur) | scaercoef_nimbus_x_sirs_opac.dat (same file for sirs-blur) | scaercoef_nimbus_x_sirs_cams.dat (same file for sirs-blur) |
| SLSTR | O3, CO2 | rtcoef_sentinel3_x_slstr_o3co2.dat | 16/10/2020 | sccldcoef_sentinel3_x_slstr.dat | scaercoef_sentinel3_x_slstr_opac.dat | scaercoef_sentinel3_x_slstr_cams.dat |
| SLSTR | O3 | rtcoef_sentinel3_x_slstr_o3.dat | 16/10/2020 | As above | As above | As above |
| SLSTR | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_sentinel3_x_slstr_7gas.dat | 16/10/2020 | As above | As above | As above |
| SSH | O3, CO2 | rtcoef_dmsp_x_ssh_o3co2.dat | 28/07/2022 | - | - | - |
| SSTM | O3, CO2 | rtcoef_oceansat_3_sstm_o3co2.dat | 02/12/2022 | sccldcoef_oceansat_3_sstm.dat | scaercoef_oceansat_3_sstm_opac.dat | scaercoef_oceansat_3_sstm_cams.dat |
| SSTM | O3 | rtcoef_oceansat_3_sstm_o3.dat | 02/12/2022 | As above | As above | As above |
| THIR | O3, CO2 | rtcoef_nimbus_x_thir_o3co2.dat | 16/10/2020 | sccldcoef_nimbus_x_thir.dat | scaercoef_nimbus_x_thir_opac.dat | scaercoef_nimbus_x_thir_cams.dat |
| TIRS | O3, CO2 | rtcoef_landsat_x_tirs_o3co2.dat | 16/10/2020 25/06/2023 | sccldcoef_landsat_x_tirs.dat | scaercoef_landsat_x_tirs_opac.dat | scaercoef_landsat_x_tirs_cams.dat |
| TIRS | O3 | rtcoef_landsat_x_tirs_o3.dat | 16/10/2020 25/06/2023 | As above | As above | As above |
| TIRS | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_landsat_9_tirs_7gas.dat | 25/06/2023 | As above | As above | As above |
| TM | O3, CO2 | rtcoef_landsat_x_tm_o3co2.dat | 27/10/2022 | sccldcoef_landsat_x_tm.dat | scaercoef_landsat_x_tm_opac.dat | scaercoef_landsat_x_tm_cams.dat |
| TRISHNA-TIR | O3, CO2 | rtcoef_trishna_1_tir_o3co2.dat | 06/05/2021 | sccldcoef_trishna_1_tir.dat | scaercoef_trishna_1_tir_opac.dat | scaercoef_trishna_1_tir_cams.dat |
| TRISHNA-TIR | O3 | rtcoef_trishna_1_tir_o3.dat | 06/05/2021 | As above | As above | As above |
| TRISHNA-TIR | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_trishna_1_tir_7gas.dat | 06/05/2021 | As above | As above | As above |
| VIIRS | O3, CO2 | rtcoef_jpss_0_viirs_o3co2.dat rtcoef_noaa_xx_viirs_o3co2.dat | 16/10/2020 30/06/2022 | sccldcoef_jpss_0_viirs.dat sccldcoef_noaa_xx_viirs.dat | scaercoef_jpss_0_viirs_opac.dat scaercoef_noaa_xx_viirs_opac.dat | scaercoef_jpss_0_viirs_cams.dat scaercoef_noaa_xx_viirs_cams.dat |
| VIIRS | O3 | rtcoef_jpss_0_viirs_o3.dat rtcoef_noaa_xx_viirs_o3.dat | 16/10/2020 30/06/2022 | As above | As above | As above |
| VIIRS | O3, CO2, N2O, CO, CH4, SO2 | rtcoef_noaa_21_viirs_7gas.dat | 30/06/2022 | As above | As above | As above |
| VIMS | O3, CO2 | rtcoef_gf5_1_vims_o3co2.dat | 16/10/2020 | sccldcoef_gf5_1_vims.dat | scaercoef_gf5_1_vims_opac.dat | scaercoef_gf5_1_vims_cams.dat |
| VIMS | O3 | rtcoef_gf5_1_vims_o3.dat | 16/10/2020 | As above | As above | As above |
| VIRR | O3, CO2 | rtcoef_fy3_3_virr_o3co2.dat | 16/10/2020 | sccldcoef_fy3_3_virr.dat | scaercoef_fy3_3_virr_opac.dat | scaercoef_fy3_3_virr_cams.dat |
| VIRR | O3 | rtcoef_fy3_3_virr_o3.dat | 16/10/2020 | As above | As above | As above |
| VISSR | O3, CO2 | rtcoef_fy2_x_vissr_o3co2.dat | 16/10/2020 10/05/2021 | sccldcoef_fy2_x_vissr.dat | scaercoef_fy2_x_vissr_opac.dat | scaercoef_fy2_x_vissr_cams.dat |
| VISSR | O3 | rtcoef_fy2_x_vissr_o3.dat | 16/10/2020 10/05/2021 | As above | As above | As above |
| VTPR | O3, CO2 | rtcoef_noaa_x_vtpr1_o3co2.dat | 16/10/2020 | - | - | - |
NB “NOAA-5” is TIROS-N.
* The ERS-1 ATSR coefficient file contains coefficients for 7 channels: 1-4 are the standard channels (12, 11, 3.7, 1.6 microns respectively) and 5-7 are additional coefficients for the 12 micron channel using spectral responses valid at different sensor temperatures. The corresponding cloud and aerosol coefficients have been generated using this coefficient file and as such contain data for the 7 channels in the rtcoef file.
** The MTG LI file contains coefficients for two channels with SRFs corresponding to incidence angles of 0 and 5.1 degrees (channels 1 and 2 respectively).
*** The channel indexing in the OLCI coefficients is a special case: see the file headers for information on the channel indexing. Due to their size, the OLCI cloud optical property files are linked in the table above.
**** The MVIRI-VIS files contain coefficients for the MVIRI visible channel at 0.6 microns. As described in Quast et al (2019), the spectral response functions (SRFs) for this channel on each MVIRI platform have been changing over time, typically with more rapid change earlier in their lifetime than towards the end. The SRFs have been characterised at 45 day intervals throughout each satellite’s lifetime. Within each full year the SRFs were determined for the same days, starting at day 33 and ending at day 348. These MVIRI-VIS coefficient files contain one channel for each SRF for each platform and each file has a different number of channels since each platform had a different lifespan. The “README_SPECTRAL_RESPONSE_FUNCTION” section within each file provides the validity date of the first and last SRFs/channels in each file as YYYYDDD where YYYY is the year, and DDD is the day of the year. Users may wish to select the SRF/channel closest in time to that of their simulation. The contents of the files are summarised in this text file. An example Python function has been created which can be used to return the channel number corresponding to the SRF valid closest to the specified date for the specified Meteosat platform.
IR-only optical depth coefs and cloud/aerosol optical properties
The tarballs of coefficient files linked above contain files for all non-hyperspectral visible/IR sensors currently supported by RTTOV. In all cases, the files contain coefficients for all currently supported channels for each sensor. For sensors with both visible and IR channels you may want the optical depth coefficient and cloud/aerosol optical property files for just the IR channels. The tarballs below contain coefficients/properties for the IR channels only for those sensors.
You might want to use these files if you are replacing existing v7/v8 predictor rtcoef files (which support only IR channels) with equivalent v13 predictor coefficient files for sensors with VIS+IR channels.
You might want to use the cloud/aerosol optical property files if you are running scattering simulations using v7/v8 predictor rtcoef files for sensors with VIS+IR channels.
Note that you can extract subsets of channels (e.g. IR channels) from coefficient files using the tool described here.
- 54L IR-only v13 predictor variable O3+CO2 files – extract to rtcoef_rttov13/rttov13pred54L/
- 54L IR-only v13 predictor variable O3 files – extract to rtcoef_rttov13/rttov13pred54L/
- 54L IR-only v13 predictor 7gas files – extract to rtcoef_rttov13/rttov13pred54L/
- IR-only cloud scattering property files – extract to rtcoef_rttov13/cldaer_ir/
- IR-only OPAC aerosol scattering property files – extract to rtcoef_rttov13/cldaer_ir/
- IR-only CAMS aerosol scattering property files – extract to rtcoef_rttov13/cldaer_ir/
MFASIS NN files for visible cloud simulations
RTTOV v13.2 introduced the neural network-based MFASIS-NN. This will replace the LUT-based MFASIS in future releases. MFASIS-NN files are used alongside visible/IR rtcoef and sccldcoef files for the same sensor. MFASIS-NN files can be used with both OPAC or “Deff” cloud liquid water optical properties (unlike the LUTs which are specific to one or the other) and currently must be used with the Baum ice cloud optical properties (as for the LUTs). See below for information about cloud liquid and ice water optical properties.
MFASIS-NN files are much smaller than the LUT files and as such are available in ASCII format so that the HDF5 library is not required.
Some sensor channels supported by MFASIS-LUT are not yet supported by MFASIS-NN. This is the case for the SEVIRI 0.8 um channel for which water vapour must be taken into account. This will be addressed in a future RTTOV release.
The table below lists the channels currently supported by MFASIS-NN: please note these carefully as sometimes the NN files for the same sensor on different platforms supports different channels due to technical issues in the NN training. We are working to address these issues.
Downloads
- RTTOV MFASIS-NN coefficient files for all currently supported sensors – extract to rtcoef_rttov13/mfasis_nn/.
- MFASIS-NN files for sensors not listed in the table can be requested via the NWP SAF Helpdesk, but note the limitations given above related to certain sensor channels.
- MFASIS currently supports channels at wavelengths up to 1.6 microns.
| Sensor | Associated rtcoef filename | Associated cloud coef filename | Supported channels (RTTOV channel numbers) | MFASIS NN file | Date of MFASIS-NN file creation |
|---|---|---|---|---|---|
| ABI | rtcoef_goes_16_abi*.dat rtcoef_goes_17_abi*.dat rtcoef_goes_18_abi*.dat | sccldcoef_goes_16_abi.dat sccldcoef_goes_17_abi.dat sccldcoef_goes_18_abi.dat | 1,2,3,5 | rttov_mfasis_nn_goes_16_abi.dat rttov_mfasis_nn_goes_17_abi.dat rttov_mfasis_nn_goes_18_abi.dat | 21/11/2022 05/12/2022 05/12/2022 |
| AHI | rtcoef_himawari_8_ahi*.dat rtcoef_himawari_9_ahi*.dat | sccldcoef_himawari_8_ahi.dat sccldcoef_himawari_9_ahi.dat | 1,2,3,4,5 | rttov_mfasis_nn_himawari_8_ahi.dat rttov_mfasis_nn_himawari_9_ahi.dat | 29/03/2023 29/03/2023 |
| AMI | rtcoef_gkompsat2_1_ami*.dat | sccldcoef_gkompsat2_1_ami.dat | 1,2,3,4,6 | rttov_mfasis_nn_gkompsat2_1_ami.dat | 21/11/2022 |
| AVHRR | rtcoef_metop_1_avhrr*.dat rtcoef_metop_2_avhrr*.dat rtcoef_metop_3_avhrr*.dat | sccldcoef_metop_1_avhrr.dat sccldcoef_metop_2_avhrr.dat sccldcoef_metop_3_avhrr.dat | 1,3 | rttov_mfasis_nn_metop_1_avhrr.dat rttov_mfasis_nn_metop_2_avhrr.dat rttov_mfasis_nn_metop_3_avhrr.dat | 21/11/2022 05/12/2022 05/12/2022 |
| AVHRR | rtcoef_noaa_14_avhrr*.dat | sccldcoef_noaa_14_avhrr.dat | 1,2 (channel 2 errors are larger than usual) | rttov_mfasis_nn_noaa_14_avhrr.dat | 08/01/2024 |
| EPIC (see notes below) | rtcoef_dscovr_1_epic*.dat | sccldcoef_dscovr_1_epic.dat | 1,2,3,6 | rttov_mfasis_nn_dscovr_1_epic.dat | 21/11/2022 |
| FCI | rtcoef_mtg_1_fci*.dat | sccldcoef_mtg_1_fci.dat | 1,2,3,4,7 | rttov_mfasis_nn_mtg_1_fci.dat | 21/11/2022 |
| GOES imager | rtcoef_goes_13_imager*.dat rtcoef_goes_14_imager*.dat rtcoef_goes_15_imager*.dat | sccldcoef_goes_13_imager.dat sccldcoef_goes_14_imager.dat sccldcoef_goes_15_imager.dat | 1 | rttov_mfasis_nn_goes_13_imager.dat rttov_mfasis_nn_goes_14_imager.dat rttov_mfasis_nn_goes_15_imager.dat | 10/01/2024 |
| METImage | rtcoef_metopsg_1_metimage*.dat | sccldcoef_metopsg_1_metimage.dat | 1,2,3,4,6,8,10 | rttov_mfasis_nn_metopsg_1_metimage.dat | 21/11/2022 |
| MODIS | rtcoef_eos_1_modis*.dat rtcoef_eos_2_modis*.dat | sccldcoef_eos_1_modis.dat sccldcoef_eos_2_modis.dat | 1,2,3,4,5,6,8,9,10,11,12,13,14,15,16 | rttov_mfasis_nn_eos_1_modis.dat rttov_mfasis_nn_eos_2_modis.dat | 29/03/2023 05/12/2022 |
| SEVIRI | rtcoef_msg_1_seviri*.dat rtcoef_msg_2_seviri*.dat rtcoef_msg_3_seviri*.dat rtcoef_msg_4_seviri*.dat | sccldcoef_msg_1_seviri.dat sccldcoef_msg_2_seviri.dat sccldcoef_msg_3_seviri.dat sccldcoef_msg_4_seviri.dat | 1,3 | rttov_mfasis_nn_msg_1_seviri.dat rttov_mfasis_nn_msg_2_seviri.dat rttov_mfasis_nn_msg_3_seviri.dat rttov_mfasis_nn_msg_4_seviri.dat | 05/12/2022 05/12/2022 05/12/2022 21/11/2022 |
| VIIRS | rtcoef_jpss_0_viirs*.dat rtcoef_noaa_20_viirs*.dat rtcoef_noaa_21_viirs*.dat | sccldcoef_jpss_0_viirs.dat sccldcoef_noaa_20_viirs.dat sccldcoef_noaa_21_viirs.dat | 1,2,3,4,5,6,7,8,9,11,14 | rttov_mfasis_nn_jpss_0_viirs.dat rttov_mfasis_nn_noaa_20_viirs.dat rttov_mfasis_nn_noaa_21_viirs.dat | 21/11/2022 29/03/2023 05/12/2022 |
Notes:
EPIC
RTTOV currently only supports channels 5-10 of the EPIC sensor. In RTTOV these supported channels are numbered 1-6. The EPIC MFASIS NNs support only channels 1, 2, 3 and 6 of these (5, 6, 7, and 10 in the instrument channel numbering): channels 4 and 5 (8 and 9, at 688nm and 764nm) are not currently simulated by MFASIS because the significant O2 absorption means that the amount of atmosphere between the sensor and the cloud must be accounted for, and this is not yet implemented in MFASIS-NN. In addition the EPIC NNs are trained for a restricted set of scattering angles (4-14 degrees, where zero represents direct back-scatter) appropriate to the orbit of this sensor.
MFASIS LUT files for visible cloud simulations
The MFASIS LUTs must be used alongside visible/IR rtcoef and sccldcoef files for the same sensor. MFASIS LUTs are trained using either the OPAC cloud liquid water (CLW) properties or the “Deff” CLW properties. All LUTs are trained using the Baum ice cloud optical properties. MFASIS simulations must specify the same clw_scheme and ice_scheme profile variables as used in training the LUT. See below for information about cloud liquid and ice water schemes. The executable rttov_mfasis_lut_info.exe prints out information about a given MFASIS LUT: see Annex A in the user guide for details.
For RTTOV v13 the MFASIS LUTs have been regenerated using the new Rayleigh multiple scattering capability in RTTOV and using the updated cloud liquid water optical properties. The new files also include additional information on the geometry used for training the LUTs which is enables improved quality flagging of out-of-bounds simulation geometries. The new files are recommended over previous v12 LUTs, but the old files can be used with RTTOV v13.
RTTOV v13.1 introduces support for 1.6 micron channels. New LUT files are available supporting this channel: these cannot be used with earlier versions of RTTOV. All pre-existing LUT files can be used with v13.1.
For relevant sensors/channels the LUTs take account of variable water vapour. Currently this only applies to the SEVIRI 0.8um channel.
This document gives some guidance on the accuracy of the MFASIS parameterisation vs the RTTOV-DOM training simulations.
The new v13 files (excluding those supporting 1.6 micron files) can be used with RTTOV v12 but note the following caveats:
1. Strictly speaking an MFASIS LUT file should be used with the same sccldcoef file used to generate the LUT. The new cloud liquid water optical properties are not available for RTTOV v12. However, the new optical properties do not differ greatly from the old properties available for RTTOV v12 at wavelengths below 1 micron and as such the new v13 MFASIS LUTs can be used with RTTOV v12 on the understanding that the simulation errors may be slightly larger. The benefits of the Rayleigh multiple scattering should outweigh this.
2. The improved quality flagging is not supported in v12. This may be important for some sensors (e.g. DSCOVR/EPIC) which have particular viewing geometries.
Downloads
- All files are linked in the table below. LUT files for sensors not listed in the table can be requested via the NWP SAF Helpdesk.
- MFASIS LUT files are in HDF5 format due to their large size. These can be read in alongside ASCII rtcoef and sccldcoef files.
- MFASIS currently supports channels at wavelengths up to 1.6 micron.
- Old MFASIS LUT files for channels at wavelengths below 1 micron (for use with RTTOV v13.0 and earlier) are indicated with “_sub1micron” in the filenames.
- Download required files to rtcoef_rttov13/mfasis_lut/
| Sensor | Associated rtcoef filename | Associated cloud coef filename | Compatible RTTOV versions | Supported channels (RTTOV channel numbers) | MFASIS LUT file: OPAC CLW | Date of OPAC CLW file creation | MFASIS LUT file: Deff CLW | Date of Deff CLW file creation |
|---|---|---|---|---|---|---|---|---|
| ABI (see notes below) | rtcoef_goes_16_abi*.dat rtcoef_goes_17_abi*.dat rtcoef_goes_18_abi*.dat | sccldcoef_goes_16_abi.dat sccldcoef_goes_17_abi.dat sccldcoef_goes_18_abi.dat | v13.2, v13.1 | 1,2,3,5 | rttov_mfasis_cld_goes_16_abi_opac.H5 rttov_mfasis_cld_goes_17_abi_opac.H5 rttov_mfasis_cld_goes_18_abi_opac.H5 | 01/08/2023 | rttov_mfasis_cld_goes_16_abi_deff.H5 rttov_mfasis_cld_goes_17_abi_deff.H5 rttov_mfasis_cld_goes_18_abi_deff.H5 | 01/08/2023 |
| ABI | rtcoef_goes_16_abi*.dat rtcoef_goes_17_abi*.dat rtcoef_goes_18_abi*.dat | sccldcoef_goes_16_abi.dat sccldcoef_goes_17_abi.dat sccldcoef_goes_18_abi.dat | v13.2, v13.1, v13.0, v12.3 | 1,2,3 | rttov_mfasis_cld_goes_16_abi_opac_sub1micron.H5 rttov_mfasis_cld_goes_17_abi_opac_sub1micron.H5 rttov_mfasis_cld_goes_18_abi_opac_sub1micron.H5 | 16/09/2020 14/09/2020 25/06/2022 | rttov_mfasis_cld_goes_16_abi_deff_sub1micron.H5 rttov_mfasis_cld_goes_17_abi_deff_sub1micron.H5 rttov_mfasis_cld_goes_18_abi_deff_sub1micron.H5 | 06/09/2020 07/09/2020 01/07/2022 |
| AHI (see notes below) | rtcoef_himawari_8_ahi*.dat rtcoef_himawari_9_ahi*.dat | sccldcoef_himawari_8_ahi.dat sccldcoef_himawari_9_ahi.dat | v13.2, v13.1 | 1,2,3,4,5 | rttov_mfasis_cld_himawari_8_ahi_opac.H5 rttov_mfasis_cld_himawari_9_ahi_opac.H5 | 13/09/2020 16/09/2020 | rttov_mfasis_cld_himawari_8_ahi_deff.H5 rttov_mfasis_cld_himawari_9_ahi_deff.H5 | 04/09/2020 07/09/2020 |
| AHI | rtcoef_himawari_8_ahi*.dat rtcoef_himawari_9_ahi*.dat | sccldcoef_himawari_8_ahi.dat sccldcoef_himawari_9_ahi.dat | v13.2, v13.1, v13.0, v12.3 | 1,2,3,4 | rttov_mfasis_cld_himawari_8_ahi_opac_sub1micron.H5 rttov_mfasis_cld_himawari_9_ahi_opac_sub1micron.H5 | 13/09/2020 16/09/2020 | rttov_mfasis_cld_himawari_8_ahi_deff_sub1micron.H5 rttov_mfasis_cld_himawari_9_ahi_deff_sub1micron.H5 | 04/09/2020 07/09/2020 |
| AMI | rtcoef_gkompsat2_1_ami*.dat | sccldcoef_gkompsat2_1_ami.dat | v13.2, v13.1 | 1,2,3,4,6 | rttov_mfasis_cld_gkompsat2_1_ami_opac.H5 | 01/08/2023 | rttov_mfasis_cld_gkompsat2_1_ami_deff.H5 | 01/08/2023 |
| AMI | rtcoef_gkompsat2_1_ami*.dat | sccldcoef_gkompsat2_1_ami.dat | v13.2, v13.1, v13.0, v12.3 | 1,2,3,4 | rttov_mfasis_cld_gkompsat2_1_ami_opac_sub1micron.H5 | 25/08/21 | rttov_mfasis_cld_gkompsat2_1_ami_deff_sub1micron.H5 | 20/08/21 |
| EPIC (see notes below) | rtcoef_dscovr_1_epic*.dat | sccldcoef_dscovr_1_epic*.dat | v13.2, v13.1, v13.0, v12.3 | 1,2,3,6 | rttov_mfasis_cld_dscovr_1_epic_opac.H5 | 09/12/2020 | rttov_mfasis_cld_dscovr_1_epic_deff.H5 | 06/12/2020 |
| FCI (see notes below) | rtcoef_mtg_1_fci*.dat | sccldcoef_mtg_1_fci.dat | v13.2, v13.1 | 1,2,3,4,7 | rttov_mfasis_cld_mtg_1_fci_opac.H5 | 26/06/2023 | rttov_mfasis_cld_mtg_1_fci_deff.H5 | 20/06/2023 |
| FCI | rtcoef_mtg_1_fci*.dat | sccldcoef_mtg_1_fci.dat | v13.2, v13.1, v13.0, v12.3 | 1,2,3,4 | rttov_mfasis_cld_mtg_1_fci_opac_sub1micron.H5 | 26/06/2023 | rttov_mfasis_cld_mtg_1_fci_deff_sub1micron.H5 | 20/06/2023 |
| SEVIRI (includes WV correction) | rtcoef_msg_1_seviri*.dat rtcoef_msg_2_seviri*.dat rtcoef_msg_3_seviri*.dat rtcoef_msg_4_seviri*.dat | sccldcoef_msg_1_seviri.dat sccldcoef_msg_2_seviri.dat sccldcoef_msg_3_seviri.dat sccldcoef_msg_4_seviri.dat | v13.2, v13.1 | 1,2,3 | rttov_mfasis_cld_msg_1_seviri_opac.H5 rttov_mfasis_cld_msg_2_seviri_opac.H5 rttov_mfasis_cld_msg_3_seviri_opac.H5 rttov_mfasis_cld_msg_4_seviri_opac.H5 | 10/09/2020 12/09/2020 12/09/2020 10/09/2020 | rttov_mfasis_cld_msg_1_seviri_deff.H5 rttov_mfasis_cld_msg_2_seviri_deff.H5 rttov_mfasis_cld_msg_3_seviri_deff.H5 rttov_mfasis_cld_msg_4_seviri_deff.H5 | 27/08/2020 21/08/2020 15/08/2020 10/08/2020 |
| SEVIRI (includes WV correction) | rtcoef_msg_1_seviri*.dat rtcoef_msg_2_seviri*.dat rtcoef_msg_3_seviri*.dat rtcoef_msg_4_seviri*.dat | sccldcoef_msg_1_seviri.dat sccldcoef_msg_2_seviri.dat sccldcoef_msg_3_seviri.dat sccldcoef_msg_4_seviri.dat | v13.2, v13.1, v13.0, v12.3 | 1,2 | rttov_mfasis_cld_msg_1_seviri_opac_sub1micron.H5 rttov_mfasis_cld_msg_2_seviri_opac_sub1micron.H5 rttov_mfasis_cld_msg_3_seviri_opac_sub1micron.H5 rttov_mfasis_cld_msg_4_seviri_opac_sub1micron.H5 | 10/09/2020 12/09/2020 12/09/2020 10/09/2020 | rttov_mfasis_cld_msg_1_seviri_deff_sub1micron.H5 rttov_mfasis_cld_msg_2_seviri_deff_sub1micron.H5 rttov_mfasis_cld_msg_3_seviri_deff_sub1micron.H5 rttov_mfasis_cld_msg_4_seviri_deff_sub1micron.H5 | 27/08/2020 21/08/2020 15/08/2020 10/08/2020 |
Notes:
ABI, AMI, EPIC, FCI
A channel indexing bug in the RTTOV code was discovered which means that EPIC channel 6 is not simulated correctly. There was a corresponding error in the ABI and AMI LUT files which meant that these files were not affected by the bug. The bug has been fixed, and the updated ABI and AMI LUT files above should be downloaded and used with the patched code. The new FCI LUTs must be used with the patched code. This affects RTTOV v13.1 and v13.2. It does not affect LUT files for other sensors, and it does not affect any “sub1micron” LUT files. See the bug fix dated 01/08/2023.
EPIC
RTTOV currently only supports channels 5-10 of the EPIC sensor. In RTTOV these supported channels are numbered 1-6. The EPIC MFASIS LUTs support only channels 1, 2, 3 and 6 of these (5, 6, 7, and 10 in the instrument channel numbering): channels 4 and 5 (8 and 9, at 688nm and 764nm) are not currently simulated by MFASIS because the significant O2 absorption means that the amount of atmosphere between the sensor and the cloud must be accounted for, and this is not currently possible in MFASIS. In addition the EPIC LUTs are trained for a restricted set of scattering angles (4-14 degrees, where zero represents direct back-scatter) appropriate to the orbit of this sensor.
LBLRTM v12.8 RTTOV v7/8/9 predictor coefficients
v7/8/9 predictor VIS/IR sensor coefficients based on LBLRTM v12.8 are available for most sensors. We would encourage you to use the v13 predictor files above in preference to these with RTTOV v13. These files can be used with RTTOV v12. The SSU coefficients linked here have not been updated. The v8 predictor tarball includes the Nimbus-6 PMR coefficients which have not been updated.
- 54L v7 predictor files – extract to rtcoef_rttov13/rttov7pred54L/
- 54L v8 predictor files – extract to rtcoef_rttov13/rttov8pred54L/
- 51L v8 predictor files for SSU – extract to rtcoef_rttov13/rttov8pred51L/
- 54L v9 predictor files, variable O3+CO2 – extract to rtcoef_rttov13/rttov9pred54L/
MW optical depth coefs and RTTOV-SCATT optical properties
General information on MW sensor optical depth coefficient files:
- Based on Liebe 89/92 LbL model
- All on 54 levels
- v13 predictors
- No Planck-weighted channels
- No optional trace gases except for sensors with channels above 200GHz which enable variable O3
- Not solar compatible
- Not NLTE compatible
- Not PC compatible
Downloads
- All MW rtcoef optical depth coefficients based on top-hat (box-car) pass bands – extract to rtcoef_rttov13/rttov13pred54L/.
- All MW rtcoef optical depth coefficients based on measured SRFs – extract to rtcoef_rttov13/rttov13pred54L/.
- All v7 predictor MW rtcoef optical depth coefficients based on measured SRFs – extract to rtcoef_rttov13/rttov7pred54L/.
- Zeeman coefficients are not currently available based on the v13 predictors – use the RTTOV v12 ones
- RTTOV-SCATT hydrotable files are linked in the table below – extract to rtcoef_rttov13/hydrotable/ (NB these are new for RTTOV v13 – see notes below)
- For v13.2 only: when using the new ARO scaled polarisation option, this sensor-independent file is required. Download to rtcoef_rttov13/hydrotable/ or otherwise place in the same directory as your hydrotable(s).
| Sensor | Filename | Date of rtcoef file creation | Associated hydrotable filename | Date of hydrotable file creation | Hydrotable radar-enabled? |
|---|---|---|---|---|---|
| AltiKa | rtcoef_saral_1_altika.dat | 26/02/2020 | hydrotable_saral_altika.dat | 23/09/2020 | N |
| AMR | rtcoef_jason_2_amr.dat | 26/02/2020 | - | ||
| AMR-C | rtcoef_jasoncs_1_amrc.dat | 26/02/2020 | hydrotable_jasoncs_amrc.dat | 29/10/2024 | N |
| AMSR-E | rtcoef_eos_2_amsre.dat | 26/02/2020 | hydrotable_eos_amsre.dat | 23/09/2020 | N |
| AMSR2 | rtcoef_gcom-w_1_amsr2.dat | 26/02/2020 | hydrotable_gcom-w_amsr2.dat | 23/09/2020 | N |
| AMSR3 | rtcoef_gosat-gw_1_amsr3.dat | 20/01/2023 | hydrotable_gosat-gw_amsr3.dat | 20/01/2023 | N |
| AMSU-A | rtcoef_noaa_xx_amsua.dat rtcoef_metop_x_amsua.dat rtcoef_eos_2_amsua.dat | 26/02/2020 | hydrotable_noaa_amsua.dat hydrotable_metop_amsua.dat (rename/copy noaa file) hydrotable_eos_amsua.dat (rename/copy noaa file) | 23/09/2020 | N |
| AMSUA-A SRF | rtcoef_noaa_19_amsua_srf.dat | 03/11/2021 | As above | ||
| AMSU-B | rtcoef_noaa_xx_amsub.dat | 26/02/2020 | hydrotable_noaa_amsub.dat | 23/09/2020 | N |
| ATMS | rtcoef_jpss_0_atms.dat rtcoef_noaa_20_atms.dat | 26/02/2020 | hydrotable_jpss_atms.dat hydrotable_noaa_atms.dat (rename/copy jpss file) | 23/09/2020 | N |
| ATMS SRF | rtcoef_jpss_0_atms_srf.dat rtcoef_noaa_xx_atms_srf.dat | 03/11/2021 23/11/2022 22/08/2023 | As above | ||
| AWS* | rtcoef_aws_1_aws_o3.dat | 09/05/2022 | hydrotable_aws_aws.dat | 09/05/2022 | N |
| AWS* SRF | rtcoef_aws_1_aws_o3_srf.dat | 01/07/2024 | As above | ||
| CIMR | rtcoef_cimr_1_cimr.dat | 29/08/2023 | hydrotable_cimr_cimr.dat | 29/08/2023 | N |
| COWVR | rtcoef_ors_6_cowvr.dat | 26/02/2020 | - | ||
| CPR | rtcoef_cloudsat_1_cpr.dat | 26/02/2020 | hydrotable_cloudsat_cpr.dat | 23/09/2020 | Y |
| DPR | rtcoef_gpm_1_dpr.dat | 26/02/2020 | hydrotable_gpm_dpr.dat | 23/09/2020 | Y |
| ESMR | rtcoef_nimbus_x_esmr.dat | 27/06/2022 | - | ||
| GEMS1 | rtcoef_oms_1_gems1.dat | 24/11/2020 | - | ||
| GEMS1 SRF | rtcoef_oms_1_gems1_srf.dat | 04/11/2021 | - | ||
| GMI | rtcoef_gpm_1_gmi.dat | 26/02/2020 | hydrotable_gpm_gmi.dat | 23/09/2020 | N |
| GMI SRF | rtcoef_gpm_1_gmi_srf.dat | 05/11/2021 | As above | ||
| HSB | rtcoef_eos_2_hsb.dat | 26/02/2020 | - | ||
| ICI* | rtcoef_metopsg_2_ici_o3.dat | 26/02/2020 | hydrotable_metopsg_ici.dat | 23/09/2020 | N |
| JIHENG SRF | rtcoef_jiheng_1_jiheng_srf.dat | 11/03/2024 | hydrotable_jiheng_jiheng.dat | 12/03/2024 | N |
| MADRAS | rtcoef_meghatr_1_madras.dat | 26/02/2020 | hydrotable_meghatr_madras.dat | 23/09/2020 | N |
| MIRAS | rtcoef_smos_1_miras.dat | 26/02/2020 | hydrotable_smos_miras.dat | 23/09/2020 | N |
| MHS | rtcoef_noaa_xx_mhs.dat rtcoef_metop_x_mhs.dat | 26/02/2020 | hydrotable_noaa_mhs.dat hydrotable_metop_mhs.dat (rename/copy noaa file) | 23/09/2020 | N |
| Microsat2b MHS | rtcoef_micro2b_0_mhsm2b.dat | 19/10/2022 | hydrotable_micro2b_mhsm2b.dat | 19/10/2022 | N |
| Microsat2b MHS SRF | rtcoef_micro2b_0_mhsm2b_srf.dat | 16/05/2023 | As above | ||
| MSU | rtcoef_noaa_xx_msu.dat | 26/02/2020 | - | ||
| MTVZA-GY | rtcoef_meteor-m_2_mtvzagy.dat | 26/02/2020 | hydrotable_meteor-m_mtvzagy.dat | 23/09/2020 | N |
| MWHS | rtcoef_fy3_x_mwhs.dat | 26/02/2020 | hydrotable_fy3_mwhs.dat | 23/09/2020 | N |
| FY-3C/D MWHS2 | rtcoef_fy3_x_mwhs2.dat | 26/02/2020 | hydrotable_fy3_mwhs2.dat | 23/09/2020 | N |
| FY-3E/F MWHS2 SRF | rtcoef_fy3_x_mwhs2e_srf.dat | 13/09/2022 24/01/2024 | hydrotable_fy3_mwhs2e.dat | 13/09/2022 | N |
| MetopSG MWI | rtcoef_metopsg_2_mwi.dat | 27/02/2024 | hydrotable_metopsg_mwi.dat | 23/02/2024 | N |
| WSF-M MWI SRF | rtcoef_wsfm_1_wsfmmwi_srf.dat | 31/08/2023 | - | ||
| MWR | rtcoef_ers_x_mwr.dat rtcoef_envisat_1_mwr.dat rtcoef_sentinel3_1_mwr.dat | 26/02/2020 23/03/2020 | hydrotable_ers_mwr.dat hydrotable_envisat_mwr.dat (rename/copy ers file) hydrotable_sentinel3_mwr.dat (rename/copy ers file) | 23/09/2020 | N |
| FY3 MWRI | rtcoef_fy3_x_mwri.dat | 26/02/2020 | hydrotable_fy3_mwri.dat | 23/09/2020 | N |
| FY3 MWRI2 SRF | rtcoef_fy3_6_mwri2_srf.dat | 12/02/2024 | hydrotable_fy3_mwri2.dat | 23/02/2024 | N |
| FY3 MWRI-RM | rtcoef_fy3_7_mwrirm_srf.dat | 21/02/2024 | hydrotable_fy3_mwrirm.dat | 23/02/2024 | N |
| HY2 MWRI | rtcoef_hy2_1_hy2mwri.dat | 26/02/2020 | - | ||
| MWS | rtcoef_metopsg_1_mws.dat | 26/02/2020 | hydrotable_metopsg_mws.dat | 23/09/2020 | N |
| MWTS | rtcoef_fy3_x_mwts.dat | 26/02/2020 | hydrotable_fy3_mwts.dat | 23/09/2020 | N |
| MWTS2 | rtcoef_fy3_x_mwts2.dat | 26/02/2020 | hydrotable_fy3_mwts2.dat | 23/09/2020 | N |
| MWTS3 SRF | rtcoef_fy3_x_mwts3_srf.dat | 13/10/2022 07/02/2024 | hydrotable_fy3_mwts3.dat | 25/01/2022 | N |
| NEMS | rtcoef_nimbus_5_nems.dat | 27/06/2022 | - | ||
| FY3-G PMR | rtcoef_fy3_7_fy3pmr.dat | 14/02/2024 | hydrotable_fy3_fy3pmr.dat | 23/02/2024 | Y |
| POLSIR* | rtcoef_polsir_1_polsir_o3.dat | 09/05/2022 | hydrotable_polsir_polsir.dat | 09/05/2022 | N |
| SAPHIR | rtcoef_meghatr_1_saphir.dat | 26/02/2020 | hydrotable_meghatr_saphir.dat | 23/09/2020 | N |
| SCAMS | rtcoef_nimbus_6_scams.dat | 27/06/2022 | - | ||
| SMMR | rtcoef_nimbus_7_smmr.dat | 26/02/2020 | - | ||
| SSM/I | rtcoef_dmsp_xx_ssmi.dat | 26/02/2020 | hydrotable_dmsp_ssmi.dat | 23/09/2020 | N |
| SSMIS | rtcoef_dmsp_xx_ssmis.dat | 26/02/2020 | hydrotable_dmsp_ssmis.dat | 23/09/2020 | N |
| SSM/T | rtcoef_dmsp_xx_ssmt.dat | 28/02/2022 | - | ||
| SSM/T2 | rtcoef_dmsp_xx_ssmt2.dat | 26/02/2020 | hydrotable_dmsp_ssmt2.dat | 23/09/2020 | N |
| TEMPEST SRF | rtcoef_tempest_0_tempest.dat rtcoef_tempest_1_tempest.dat | 04/11/2021 | hydrotable_tempest_tempest.dat | 23/09/2020 | N |
| TMI | rtcoef_trmm_1_tmi.dat | 26/02/2020 | hydrotable_trmm_tmi.dat | 23/09/2020 | N |
| TROPICS SRF | rtcoef_tropics_x_tropics_srf.dat | 12/04/2023 29/03/2023 | hydrotable_tropics_tropics.dat | 23/09/2020 | N |
| Windsat | rtcoef_coriolis_1_windsat.dat | 26/02/2020 | hydrotable_coriolis_windsat.dat | 23/09/2020 | N |
NB “NOAA-5” is TIROS-N.
“SRF” refers to coefficients based on measured spectral responses. These are unique to specific sensors. Other MW coefficients are based on top-hat (box-car) pass bands and are identical for the same sensor on different platforms.
* Ozone has a significant impact above 200GHz and so optical depth coefficients for sensors with channels in this range support variable O3.
New hydrotables for RTTOV v13
Hydrotables replace the old Mietables and in RTTOV v13 they allow optical properties to be specified for an arbitrary selection of hydrometeors. The hydrotables linked above contain optical properties for 5 hydrometeors: rain, snow, graupel, cloud liquid water, cloud ice water. In your code, hydrometeor concentrations must be provided in the input cld_profiles(1:nprofiles)%hydro(1:nlevels,1:nhydro) array in this same order, where nhydro=5 for the default tables. You can generate your own hydrotables with a different number of particle types (nhydro).
The latest optical properties are summarised in Geer et al (2021). The optical properties for rain are the same as in the old Mietable files and the cloud liquid water properties are very similar. These are based on results from experiments carried out at ECMWF (Lonitz and Geer, 2018) and use the Rosenkranz (2015) liquid water permittivity parameterisation. The cloud ice water and snow properties have been updated in the new hydrotables and are based on properties from the ARTS database (Eriksson et al 2018). Graupel is new, based on the ARTS column shape. The old totalice hydrometeor has been removed. In summary:
- rain: Mie sphere, Marshall-Palmer size distribution (unchanged since latest v12 Mietables)
- snow: ARTS large plate aggregate, Field07 tropical size distribution (updated for v13)
- graupel: ARTS column, Field07 tropical size distribution (new in v13)
- cloud liquid: Mie sphere, Gamma size distribution implemented within the new modified gamma framework (mostly unchanged in terms of optical properties, but with small differences from the previous gamma distribution, which was implemented internally using some scientific shortcuts)
- cloud ice: ARTS large column aggregate, Gamma PSD with generalised modified gamma parameters mu = 0, lambda = 1e4, gamma = 1 and N0 free (updated for v13)
References:
- Geer A. J., Bauer B., Lonitz K., Barlakas V., Eriksson P., Mendrok J., Doherty A., Hocking J., and Chambon P. 2021: Bulk hydrometeor optical properties for microwave and sub-millimetre radiative transfer in RTTOV-SCATT v13.0. Geosci. Model Dev., 14, 7497-7526, https://doi.org/10.5194/gmd-14-7497-2021
- Eriksson, P., Ekelund, R., Mendrok, J., Brath, M., Lemke, O., and Buehler, S. A., 2018: A general database of hydrometeor single scattering properties at microwave and sub-millimetre wavelengths, Earth Syst. Sci. Data, 10, 1301–1326 https://doi.org/10.5194/essd-10-1301-2018
- Geer, A.J. and F. Baordo, 2014: Improved scattering radiative transfer for frozen hydrometeors at microwave frequencies. Atmos. Meas. Tech., 7, 1839-1860, doi:10.5194/amt-7-1839-2014
- Liu, G., 2008: A database of microwave single-scattering properties for nonspherical ice particles. Bulletin of the American Meteorological Society, 89(10), 1563-1570.
- Lonitz, K. and Geer, A.J., 2019: Assessing the impact of different liquid water permittivity models on the fit between model and observations. Atmos. Meas. Tech., 12, 405–429, https://doi.org/10.5194/amt-12-405-2019
- Rosenkranz, P.W., 2015: A Model for the Complex Dielectric Constant of Supercooled Liquid Water at Microwave Frequencies. IEEE Trans. on Geosci. and Remote Sensing, 53, 3, 1387-1393.
Information on visible/IR cloud/aerosol files
Cloud optical property files
There are two options for predefined cloud liquid water (CLW) optical properties and two types of option for ice cloud optical properties. These are described in detail in the user guide. An overview is given here:
OPAC CLW scheme
These optical properties are based on five OPAC cloud types and vertical profiles of layer cloud concentrations are input to RTTOV in the profiles(:)%cloud(1:5,1:nlayers) array (see the user guide). The optical properties are computed from Mie theory. Each particle type has a fixed effective particle size: the particles differ in the assumed size distributions. Therefore the CLW effective diameter (profiles(:)%clwde(:)) is not used for these properties.
The OPAC dataset uses the liquid water refractive indices from Hale and Querry (1973), but they are specified at reduced spectral resolution which misses some spectral features in the indices. For RTTOV v13 the Segelstein (1981) refractive index dataset was used instead which is a development of the Hale and Querry dataset. The properties based on Segelstein can be identified by a contents “ID” of 1 in the CLW sections of the sccldcoef file as opposed to 0 for the properties based on OPAC/Hale and Querry.
All sccldcoef files contain these optical properties. MFASIS LUT files are available trained with these optical properties.
- Hale, G. M. and M. R. Querry, 1973: Optical constants of water in the 200nm to 200μm wavelength region, Appl. Opt. 12, 555- 563.
- Segelstein, D., 1981: The Complex Refractive Index of Water. Masters Thesis, Dept Physics, U. Missouri-Kansas City.
Deff CLW scheme
These optical properties are based on the Mie properties available with libRadtran: in this case there is just one particle type and the optical properties are stored in terms of particle effective diameter. RTTOV sums the cloud concentrations provided in profiles(:)%cloud(1:5,lay) for each layer lay. Typically you would just specify the cloud concentration in one column, for example, profiles(:)%cloud(1,1:nlayers). RTTOV provides a parameterisation for cloud liquid water effective diameter. Alternatively you can specify the cloud effective diameters explicitly in the profiles(:)%clwde(1:nlayers) array. See the user guide for more details.
Previously the OPAC (Hale and Querry) refractive indices were used for these properties. For RTTOV v13 they have also been updated using the Segelstein dataset, which is also used for the libRadtran Mie properties. The properties based on Segelstein can be identified by a contents “ID” of 1 in the CLW sections of the sccldcoef file as opposed to 0 for the properties based on OPAC/Hale and Querry.
All sccldcoef files contain these optical properties. MFASIS LUT files are available trained with these optical properties.
Baum ice scheme
These optical properties are stored in terms of ice effective diameter. Cloud concentrations are input to RTTOV in the profiles(:)%cloud(6,1:nlayers) array. RTTOV provides 4 parameterisations of ice effective diameter which are selected in the profiles(:)%icede_param variable. Alternatively you can specify the effective diameters explicitly in the profiles(:)%icede(1:nlayers) array. See the user guide for more details.
All sccldcoef files contain these optical properties. All MFASIS LUT files are trained with these optical properties.
Baran ice schemes
These optical properties are parameterised in terms of ice water content and temperature. Multiple parameterisations are available (see the RTTOV user guide). Ice cloud concentrations are also input to RTTOV in the profiles(:)%cloud(6,1:nlayers) array, but there is no explicit dependence on effective diameter and so the icede_param and icede profile variables are ignored.
The data for these parameterisations are stored in the code rather than in external files. MFASIS is not currently compatible with the Baran ice schemes.
Aerosol optical property files
Vertical profiles of layer aerosol concentrations are input to RTTOV in the profiles(:)%aerosols(1:naer,1:nlayers) array (see the user guide). Vertical profiles are provided for each of the aerosol types supported by the “scaercoef_*” aerosol property file being used from 1 to naer, the number of species in the aerosol file. There are two sets of aerosol property files available:
OPAC aerosol properties: these files contain optical properties for 13 species, most of which come from OPAC. Inputs to RTTOV should be dry aerosol mass ratio (kg/kg).
| Index | Shortname | Hydrophilic? | Description |
|---|---|---|---|
| 1 | INSO | N | OPAC insoluble (Hess et al 1998) |
| 2 | WASO | Y | OPAC water soluble |
| 3 | SOOT | N | OPAC soot |
| 4 | SSAM | Y | OPAC sea salt accumulated mode |
| 5 | SSCM | Y | OPAC sea salt coarse mode |
| 6 | MINM | N | OPAC mineral nucleation mode |
| 7 | MIAM | N | OPAC mineral accumulation mode |
| 8 | MICM | N | OPAC mineral coarse mode |
| 9 | MITR | N | OPAC mineral transported |
| 10 | SUSO | Y | OPAC sulphated droplets |
| 11 | VOLA | N | Volcanic ash (Matricardi 2005) |
| 12 | VAPO | N | Volcanic ash based on measurements of Eyjafjallajökull eruption (RTTOV v11 SVR) |
| 13 | ASDU | N | Asian dust: combination of the OPAC mineral nucc., acc. and coa. modes based on fit to in-situ measurements (RTTOV v11 SVR) |
References:
- Hess, M., Kepke, P., and Schult, I., 1998: Optical Properties of Aerosols and Clouds: the software package OPAC. Bul. Am. Met. Soc., 79, pp. 831-844.
- Matricardi, M., 2005: The inclusion of aerosols and clouds in RTIASI, the ECMWF fast radiative transfer model for the Infrared Atmospheric Sounding Interferometer. ECMWF Technical Memorandum 474
- RTTOV v11 Science and Validation Report
CAMS aerosol properties: these files contain optical properties for 9 species consistent with the CAMS. Inputs to RTTOV should be dry aerosol mass ratio (kg/kg) except for the sea salt types which are mass ratios at 80% relative humidity: this is consistent with CAMS outputs.
| Index | Short name | Hydrophilic? | Description |
|---|---|---|---|
| 1 | BCAR | N | Hydrophobic black carbon, fixed refractive index at all wavelengths. |
| 2 | DUS1 | N | Dust, bin 1, 0.03-0.55 micron, refractive index: Woodward 2001 |
| 3 | DUS2 | N | Dust, bin 2, 0.55-0.90 micron, refractive index: Woodward 2001 |
| 4 | DUS3 | N | Dust, bin 3, 0.90-20.0 micron, refractive index: Woodward 2001 |
| 5 | SULP | Y | Ammonium sulphate |
| 6 | SSA1 | Y | Sea salt, bin 1, 0.03-0.5 micron |
| 7 | SSA2 | Y | Sea salt, bin 2, 0.50-5.0 micron |
| 8 | SSA3 | Y | Sea salt, bin 3, 5.0-20.0 micron |
| 9 | OMAT | Y | Hydrophilic organic matter |
References:
- Bozzo, A., Benedetti, A., Flemming, J., Kipling, Z., Remy, S., 2020: An aerosol climatology for global models based on the tropospheric aerosol scheme in the Integrated Forecasting System of ECMWF, Geosci. Model Dev., 13(3), 1007–1034 doi:10.5194/gmd-13-1007-2020
Reference profiles and regression limits
RTTOV rtcoef coefficients
RTTOV coefficients are trained using a set of diverse profiles which cover a wide range of values for each atmospheric variable. The latest coefficients are trained using diverse profiles which are designed to be applicable to the whole satellite era (1970-202x). H2O is the only gas for which profiles must always be supplied. The v13 predictors introduced in RTTOV v13 support different selections of optional variable trace gases as indicated in the filename and listed below. Note that simulations using a coefficient file with more optional variable gases run slower. RTTOV v13 supports all RTTOV v12-compatible optical depth coefficients based on the v7, v8 and v9 predictors. The main difference with the v13 predictors is that solar radiation is supported in all coefficient files and as such all files support all channels (visible-IR) for which we have spectral response data.
- v13 predictors rtcoef_*_o3 : O3 (similar to v7 predictors, but now with solar radiation)
- v13 predictors rtcoef_*_o3co2 : O3 and CO2 (similar to v8 predictors, but now with solar radiation; similar to v9 predictors with variable O3 and CO2)
- v13 predictors rtcoef_*_7gas : O3, CO2, N2O, CO, CH4 and SO2 (similar to v9 predictors with all trace gases)
If no optional gas profile is supplied a fixed background profile is used. These fixed profiles are also used in training coefficients for which a particular gas cannot vary. The fixed profile concentrations are contemporary values: when simulating older instruments you may wish to use variable-CO2 coefficients so that you can supply more appropriate CO2 profiles. The fixed background profiles are contained in these comma-separated value files (gas units are ppmv with respect to dry air):
The diverse profile set also includes a selection of gases with fixed profiles in all training simulations (the “mixed gases”):
The fast optical depth calculations can be expected to be accurate for input profiles which lie within the profile “envelopes” defined by the minimum and maximum values for each profile variable on each level. By default RTTOV checks the input profile against a set of profile regression limits: it can warn if the regression limits are exceeded or, if the apply_reg_limits option is set to TRUE, clip the values to the limits where the limits are exceeded.
For some time it has been the practice in RTTOV to set the regression limits to +/-10% of the profile envelope for temperature and +/-20% of the profile envelope for each gas. For highly variable gases (such as water vapour) this stretching may be reasonable, but for less variable gases (such as CO2) the limits should probably be closer to the strict min/max envelope. It is planned to investigate and apply more appropriate stretches to the limits for each individual gas. The comma-separated value files below show the stretched limits applied within RTTOV (gas units are ppmv with respect to dry air). Note that RTTOV v12 and v13 coefficient files contain the strict profile min/max envelopes and the stretched profile limits applied within RTTOV are calculated when the coefficients are read in whereas earlier coefficient files contain the stretched limits: despite this difference the behaviour of RTTOV v12/v13 is the same as v11 and earlier in respect of the profile limits.
PC-RTTOV
PC-RTTOV coefficients are available which allow all variable trace gases (except SO2). PC-RTTOV is trained on a different set of profiles to the RTTOV optical depth coefficient files. The file linked below gives the minimum and maximum temperature and gas limits for PC-RTTOV coefficients.
PC-RTTOV coefficients for aerosol-affected simulations are also available. These are trained using profiles based on climatological combinations of the OPAC aerosol components. These PC coefficients must only be used with the OPAC aerosol files (the “Chou-only” files are recommended) and you should only specify non-zero concentrations for aerosol indices 1-10 (the components taken from OPAC). The minimum and maximum aerosol concentrations are given below in number density (cm^-3). Among the training profiles the aerosol concentrations did not vary for every type in every layer. Where the minimum and maximum limits are the same there was no variability and RTTOV automatically resets the aerosol concentrations to the values used in the training for those components/layers. Note that for the sulphates component (index 10) there was no variability at all among the training profiles so any input concentrations for sulphates will be overridden. If any regression limit is exceeded among the components/layers which varied in the training profiles, the qflag_pc_aer_reg_limits bit is set in radiance%quality(:) for the corresponding predictor channels. If the apply_reg_limits option is true, any values falling outside the limits are clipped to the respective minimum or maximum value just as for gases.