RTTOV v12 Coefficient File Downloads
Contents
NB Coefficients for visible/IR sensors here are based on LBLRTM v12.2 and will not be updated. See the RTTOV v13 coefficients download page for updated VIS/IR v7/8/9 predictor coefficients based on LBLRTM v12.8.
The rttov_coef_download.sh script supplied in the RTTOV package in the rtcoef_rttov12/ 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.
Notes on v11 compatibility
- Optical depth (rtcoef) coefficient files – you can convert ASCII and HDF5 optical depth files between v10/v11-format and v12-format using the rttov11_conv_coef_11to12.exe and rttov11_conv_coef_12to11.exe executables which are built when you compile RTTOV. Note that NLTE coefficients are not transferred for hi-res IR sounders as the v11 and v12 NLTE models are mutually incompatible. For visible/IR files you will have to select the ISEM sea surface emissivity model if you convert v11 coefficients to v12 format.
- Cloud and aerosol optical property (sccldcoef/scaercoef) files – these are mutually incompatible between v11 and v12.
- RTTOV-SCATT Mietable files – these are identical for v11 and v12.
- PC-RTTOV coefficient files – the format of PC-RTTOV files has not changed between v11 and v12 so you can use v11 PC-RTTOV coefficients with RTTOV v12 so long as you also use the corresponding v9 predictor optical depth coefficient file converted to v12 format. It is not recommended to use new v12 PC-RTTOV coefficient files (e.g. the new NLTE-compatible files) with v11 unless you know what you are doing.
Hi-res IR sounder optical depth coefficients
All hi-res IR sounder coefficient files share these characteristics:
- Based on LBLRTM v12.2 line-by-line model
- No Planck-weighted channels
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.
- The same cloud and aerosol coefficient files are used with v7, v8 and v9 predictor optical depth coefficient 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:
- v7 predictor 54L rtcoef files – download to rtcoef_rttov12/rttov7pred54L/
- v7 predictor 101L rtcoef files – download to rtcoef_rttov12/rttov7pred101L/
- v8 predictor 101L rtcoef files – download to rtcoef_rttov12/rttov8pred101L/
- v9 predictor 101L rtcoef files – download to rtcoef_rttov12/rttov9pred101L/
- All cloud/aerosol files – download to rtcoef_rttov12/cldaer_ir/
See below for information about cloud and aerosol optical property files.
*Cloud optical property files (sccldcoef) marked with an asterisk do NOT include the new Deff cloud liquid water properties (currently only IASI-NG). If you require any cloud or aerosol file not linked in the table above please request this via the Helpdesk.
**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.
***As of 5 September 2018 the CrIS-FSR instrument ID changed from 27 to 28 to distinguish it from CrIS nominal spectral resolution. The instrument ID in the coefficient file is not used by RTTOV when running simulations so there is no need to re-download the coefficient files (though the IDs have been updated in the files linked above). However the ID has changed in the latest version of the rttov_const.F90 module, and this is used by the rttov_read_coefs subroutine to construct the filename if you pass the (platform, satellite, instrument) ID triplet as an argument. Therefore if you read coefficients using the ID triplet, the instrument ID for CrIS-FSR is 27 in the RTTOV v12.2 release and earlier, but if you download the latest rttov_const.F90 (linked above) to src/main/ and recompile then the instrument ID is 28. The instrument ID will remain 28 in future releases of RTTOV.
****GIIRS coefficients were generated with the following channel configuration:
– Hamming apodization (a=0.23, 0.8cm MPD)
– There are 1682 channels
721 channels in band1 680-1130cm-1
961 channels in band2 1650-2250cm-1
– Spectral resolution = 0.625 cm-1
Metop-B/C IASI coefficients
All coefficients (including optical depth coefficients, cloud/aerosol properties, and PC coefficient files) for IASI on Metop-A/B/C are identical so the Metop-A files given above and elsewhere may be used for all three platforms.
NOAA-20 CrIS coefficients
As for IASI, all coefficients for CrIS and CrIS-FSR are identical for the SNPP (JPSS-0) and NOAA-20 platforms.
Experimental MTG-IRS coefficients have been generated using transmittances from simulated IASI spectra. The latest coefficients have been generated using the 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. This is a “light” apodisation similar to the previous “COSCAR” apodisation function and as such 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 following links for the LBL vs RTTOV statistics for each file (more information about these plots is available on the LBL/RTTOV comparison page):
- ATBD apodisation, v7 predictors 101L
- ATBD apodisation, v9 predictors 101L (O3 only)
- ATBD apodisation, v9 predictors 101L (6 gas)
Note that HTFRTC coefficients are available for MTG-IRS using the ATBD light apodisation function: radiances simulated using HTFRTC have much smaller errors than the “classical” RTTOV approach and as such HTFRTC is currently the recommended way to run clear-sky MTG-IRS simulations in RTTOV.
| Sensor | Levels | Predictors version | Trace gases | Solar? | NLTE? | Filename | Date of file creation | Associated cloud coef filename |
|---|---|---|---|---|---|---|---|---|
| MTG-IRS apodisation from ATBD | 101 | 7 | O3 | N | N | rtcoef_mtg_1_irs-atbd.H5 | 19/03/2018 | sccldcoef_mtg_1_irs.H5sccldcoef_mtg_1_irs_chou-only.H5 |
| MTG-IRS apodisation from ATBD | 101 | 9 | O3 | Y | N | rtcoef_mtg_1_irs-atbd.H5 | 19/03/2018 | As above |
| MTG-IRS apodisation from ATBD | 101 | 9 | O3, CO2, N2O, CO, CH4 | Y | N | rtcoef_mtg_1_irs-atbd_6gas.H5 | 10/03/2020 | As above |
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. 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 new 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_rttov12/rttov9pred101L/
- PC-RTTOV pccoef files – download to rtcoef_rttov12/pc/
- OPAC Aerosol optical property scaercoef files – download to rtcoef_rttov12/cldaer_ir/
| 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_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
HTFRTC coefficients are available for a number of hyperspectral IR sounders. Two files are required for HTFRTC simulations: the static coefficient file is required for all simulations and then a sensor-specific file is required for the instrument you wish to simulate. No other RTTOV coefficient files (e.g. rtcoef files) are required for HTFRTC simulations. See the user guide for more information about running HTFRTC simulations.
Downloads
- All files are linked in the table below.
- HTFRTC coefficient files are in NetCDF format.
- Download required files to rtcoef_rttov12/htfrtc/
| Sensor | Trace gases | HTFRTC coef filename | Date of file creation |
|---|---|---|---|
| Static file (RTTOV v12.2) - required for all HTFRTC simulations | O3 (mandatory) | htfrtc_coef_static_v12.2.nc | 26/03/2018 |
| Static file (RTTOV v12.3) - required for all HTFRTC simulations | O3, CO2, N2O, CO, CH4, SO2 (all optional) | htfrtc_coef_static.nc | 31/01/2019 |
| AIRS | Determined by static file | htfrtc_coef_sensor_eos_airs.nc | 26/03/2018 |
| CrIS | Determined by static file | htfrtc_coef_sensor_jpss_cris.nc | 26/03/2018 |
| CrIS-FSR | Determined by static file | htfrtc_coef_sensor_jpss_cris_fsr.nc | 26/03/2018 |
| IASI | Determined by static file | htfrtc_coef_sensor_metop_iasi.nc | 26/03/2018 |
| IASI-NG | Determined by static file | htfrtc_coef_sensor_metopsg_iasing.nc | 26/03/2018 |
| MTG-IRS* | Determined by static file | htfrtc_coef_sensor_mtg_irs.nc | 26/03/2018 |
*MTG-IRS coefficients are for lightly apodised radiances. Apodisation function described in 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. HTFRTC can support any apodisation function: alternative/new HTFRTC coefficients for any hyperspectral IR sensor may be requested via the Helpdesk.
Ensure you download the static file appropriate to your version of RTTOV (v12.2 or v12.3). The static file determines the variable trace gases available, as indicated in the table. The sensor-specific files can be used with RTTOV v12.2 and v12.3.
The IASI file is applicable to Metop-A, -B and -C, and the CrIS and CrIS-FSR files are applicable to both JPSS-0 (SNPP) and NOAA-20.
IR optical depth coefficients
All IR coefficient files share these characteristics:
- Based on LBLRTM v12.2 line-by-line model (except SSU which is based on LBLRTM v12.0)
- 54 levels (except SSU on 51 levels and PMR on 84 levels)
- Coefficients available based on v7 predictors allowing variable O3 and v8 predictors allowing variable O3 and CO2
- Coefficients trained for zenith angles up to ~65 degrees, valid for zenith angles up to 75 degrees
- Not solar compatible
- Not NLTE compatible
- Not PC compatible
For most instruments files are available for v7 predictors (variable O3) and v8 predictors (variable O3 and CO2). The CO2 concentration used to generate the v7 predictor files is contemporary (~400ppm) so for simulations of historical atmospheric profiles the v8 predictor files may be preferable as they allow you to specify a more appropriate CO2 profile.
Downloads
- 54L v7 predictor (variable O3) files for all IR sensors – extract to rtcoef_rttov12/rttov7pred54L/
- 54L v8 predictor (variable O3, CO2) files for all IR sensors – extract to rtcoef_rttov12/rttov8pred54L/
- 51L v8 predictor SSU files – extract to rtcoef_rttov12/rttov8pred51L/
- Cloud scattering coefficient files for all sensors – extract to rtcoef_rttov12/cldaer_ir/
- OPAC Aerosol scattering coefficient files for all sensors – extract to rtcoef_rttov12/cldaer_ir/
- CAMS Aerosol scattering coefficient files for all sensors – extract to rtcoef_rttov12/cldaer_ir/
See below for information about cloud and aerosol optical property files.
| Sensor | Predictors version | Trace gases | Filename | Date of file creation | Associated cloud coef filename | Associated OPAC aerosol coef filename | Associated CAMS aerosol coef filename |
|---|---|---|---|---|---|---|---|
| (A)ATSR* | 7 / 8 | O3 / O3, CO2 | rtcoef_ers_x_atsr.dat rtcoef_envisat_1_atsr.dat | 05/10/2016 10/11/2016 | sccldcoef_ers_x_atsr.dat sccldcoef_envisat_1_atsr.dat | scaercoef_ers_x_atsr.dat scaercoef_envisat_1_atsr.dat | scaercoef_ers_x_atsr_cams.dat scaercoef_envisat_1_atsr_cams.dat |
| AATSR-shifted Info on AATSR 12 um anomaly | 7 / 8 | O3 / O3, CO2 | rtcoef_envisat_1_atsr-shifted.dat | 05/10/2016 10/11/2016 | sccldcoef_envisat_1_atsr-shifted.dat | scaercoef_envisat_1_atsr-shifted.dat | scaercoef_envisat_1_atsr-shifted_cams.dat |
| ABI | 7 / 8 | O3 / O3, CO2 | rtcoef_goes_xx_abi.dat | 05/10/2016 10/11/2016 | sccldcoef_goes_xx_abi.dat | scaercoef_goes_xx_abi.dat | scaercoef_goes_xx_abi_cams.dat |
| AGRI | 7 / 8 | O3 / O3, CO2 | rtcoef_fy4_1_agri.dat | 24/05/2018 | sccldcoef_fy4_1_agri.dat | scaercoef_fy4_1_agri.dat | scaercoef_fy4_1_agri_cams.dat |
| AHI | 7 / 8 | O3 / O3, CO2 | rtcoef_himawari_x_ahi.dat | 05/10/2016 10/11/2016 | sccldcoef_himawari_x_ahi.dat | scaercoef_himawari_x_ahi.dat | scaercoef_himawari_x_ahi_cams.dat |
| AMI | 7 / 8 | O3 / O3, CO2 | rtcoef_gkompsat2_1_ami.dat | 15/10/2019 | sccldcoef_gkompsat2_1_ami.dat | scaercoef_gkompsat2_1_ami.dat | scaercoef_gkompsat2_1_ami_cams.dat |
| ASTER | 7 / 8 | O3 / O3, CO2 | rtcoef_eos_1_aster.dat | 05/10/2016 10/11/2016 | sccldcoef_eos_1_aster.dat | scaercoef_eos_1_aster.dat | scaercoef_eos_1_aster_cams.dat |
| AVHRR | 7 / 8 | O3 / O3, CO2 | rtcoef_noaa_xx_avhrr.dat rtcoef_metop_x_avhrr.dat | 05/10/2016 10/11/2016 13/11/2018 | scaercoef_noaa_xx_avhrr.dat scaercoef_metop_x_avhrr.dat | scaercoef_noaa_xx_avhrr.dat scaercoef_metop_x_avhrr.dat | scaercoef_noaa_xx_avhrr_cams.dat scaercoef_metop_x_avhrr_cams.dat |
| ECOSTRESS | 7 / 8 | O3 / O3, CO2 | rtcoef_iss_1_ecostres.dat | 10/08/2018 | sccldcoef_iss_1_ecostres.dat | scaercoef_iss_1_ecostres.dat | scaercoef_iss_1_ecostres_cams.dat |
| FCI | 7 / 8 | O3 / O3, CO2 | rtcoef_mtg_1_fci.dat | 04/01/2017 | sccldcoef_mtg_1_fci.dat | scaercoef_mtg_1_fci.dat | scaercoef_mtg_1_fci_cams.dat |
| GMS imager | 7 / 8 | O3 / O3, CO2 | rtcoef_gms_x_imager.dat | 01/03/2017 02/03/2017 | sccldcoef_gms_x_imager.dat | scaercoef_gms_x_imager.dat | scaercoef_gms_x_imager_cams.dat |
| GOES imager | 7 / 8 | O3 / O3, CO2 | rtcoef_goes_xx_imager.dat | 05/10/2016 10/11/2016 | sccldcoef_goes_xx_imager.dat | scaercoef_goes_xx_imager.dat | scaercoef_goes_xx_imager_cams.dat |
| GOES sounder | 7 / 8 | O3 / O3, CO2 | rtcoef_goes_xx_sounder.dat | 05/10/2016 10/11/2016 | sccldcoef_goes_xx_sounder.dat | scaercoef_goes_xx_sounder.dat | scaercoef_goes_xx_sounder_cams.dat |
| HIRS | 7 / 8 | O3 / O3, CO2 | rtcoef_noaa_xx_hirs.dat rtcoef_metop_x_hirs.dat rtcoef_nimbus_6_hirs.dat | 05/10/2016 10/11/2016 | sccldcoef_noaa_xx_hirs.dat sccldcoef_metop_x_hirs.dat sccldcoef_nimbus_6_hirs.dat | scaercoef_noaa_xx_hirs.dat scaercoef_metop_x_hirs.dat scaercoef_nimbus_6_hirs.dat | scaercoef_noaa_xx_hirs_cams.dat scaercoef_metop_x_hirs_cams.dat scaercoef_nimbus_6_hirs_cams.dat |
| HIRS shifted spectral response | 7 / 8 | O3 / O3, CO2 | rtcoef_noaa_xx_hirs-shifted.dat rtcoef_metop_x_hirs-shifted.dat | 17/10/2017 17/05/2017 | sccldcoef_noaa_xx_hirs-shifted.dat sccldcoef_metop_x_hirs-shifted.dat | scaercoef_noaa_xx_hirs-shifted.dat scaercoef_metop_x_hirs-shifted.dat | scaercoef_noaa_xx_hirs-shifted_cams.dat scaercoef_metop_x_hirs-shifted_cams.dat |
| HRIR | 7 / 8 | O3 / O3, CO2 | rtcoef_nimbus_x_hrir.dat | 14/10/2019 15/10/2019 | - | - | - |
| IIR | 7 / 8 | O3 / O3, CO2 | rtcoef_calipso_1_iir.dat | 05/10/2016 10/11/2016 | sccldcoef_calipso_1_iir.dat | scaercoef_calipso_1_iir.dat | scaercoef_calipso_1_iir_cams.dat |
| INSAT-3D(R) imager | 7 / 8 | O3 / O3, CO2 | rtcoef_insat3_x_imager.dat | 05/10/2016 10/11/2016 | sccldcoef_insat3_x_imager.dat | scaercoef_insat3_x_imager.dat | scaercoef_insat3_x_imager_cams.dat |
| INSAT-3D(R) sounder | 7 / 8 | O3 / O3, CO2 | rtcoef_insat3_x_sounder.dat | 05/10/2016 10/11/2016 13/11/2016 | sccldcoef_insat3_x_sounder.dat | scaercoef_insat3_x_sounder.dat | scaercoef_insat3_x_sounder_cams.dat |
| IRAS | 7 / 8 | O3 / O3, CO2 | rtcoef_fy3_1_iras.dat | 05/10/2016 10/11/2016 | sccldcoef_fy3_1_iras.dat | scaercoef_fy3_1_iras.dat | scaercoef_fy3_1_iras_cams.dat |
| IRMSS | 7 / 8 | O3 / O3, CO2 | rtcoef_hj1_2_irmss.dat | 05/10/2016 10/11/2016 | sccldcoef_hj1_2_irmss.dat | scaercoef_hj1_2_irmss.dat | scaercoef_hj1_2_irmss_cams.dat |
| MBFIRI | 7 / 8 | O3 / O3, CO2 | rtcoef_ticfire_1_mbfiri.dat | 15/09/2017 | sccldcoef_ticfire_1_mbfiri.dat | scaercoef_ticfire_1_mbfiri.dat | scaercoef_ticfire_1_mbfiri_cams.dat |
| MERSI-1 | 7 / 8 | O3 / O3, CO2 | rtcoef_fy3_3_mersi1.dat | 05/10/2016 10/11/2016 | sccldcoef_fy3_3_mersi1.dat | scaercoef_fy3_3_mersi1.dat | scaercoef_fy3_3_mersi1_cams.dat |
| MERSI-2 | 7 / 8 | O3 / O3, CO2 | rtcoef_fy3_4_mersi2.dat | 23/11/2018 | sccldcoef_fy3_4_mersi2.dat | scaercoef_fy3_4_mersi2.dat | scaercoef_fy3_4_mersi2_cams.dat |
| MetImage | 7 / 8 | O3 / O3, CO2 | rtcoef_metopsg_1_metimage.dat | 19/05/2020 | sccldcoef_metopsg_1_metimage.dat | scaercoef_metopsg_1_metimage.dat | scaercoef_metopsg_1_metimage_cams.dat |
| MI | 7 / 8 | O3 / O3, CO2 | rtcoef_coms_1_mi.dat | 16/10/2017 | sccldcoef_coms_1_mi.dat | scaercoef_coms_1_mi.dat | scaercoef_coms_1_mi_cams.dat |
| MODIS | 7 / 8 | O3 / O3, CO2 | rtcoef_eos_x_modis.dat | 28/11/2016 | sccldcoef_eos_x_modis.dat | scaercoef_eos_x_modis.dat | scaercoef_eos_x_modis_cams.dat |
| MODIS shifted spectral response | 7 / 8 | O3 / O3, CO2 | rtcoef_eos_x_modis-shifted.dat | 28/11/2016 | sccldcoef_eos_x_modis-shifted.dat | scaercoef_eos_x_modis-shifted.dat | scaercoef_eos_x_modis-shifted_cams.dat |
| MRIR | 7 / 8 | O3 / O3, CO2 | rtcoef_nimbus_x_mrir.dat | 24/09/2019 05/10/2016 10/11/2016 | - | - | - |
| MSUGS | 7 / 8 | O3 / O3, CO2 | rtcoef_electro-l_2_msugs.dat | 25/11/2019 | sccldcoef_electro-l_2_msugs.dat | scaercoef_electro-l_2_msugs.dat | scaercoef_electro-l_2_msugs_cams.dat |
| MSUMR | 7 / 8 | O3 / O3, CO2 | rtcoef_meteor-m_x_msumr.dat | 05/10/2016 10/11/2016 21/08/2018 | sccldcoef_meteor-m_x_msumr.dat | scaercoef_meteor-m_x_msumr.dat | scaercoef_meteor-m_x_msumr_cams.dat |
| MTSAT imager | 7 / 8 | O3 / O3, CO2 | rtcoef_mtsat_x_imager.dat | 05/10/2016 10/11/2016 | sccldcoef_mtsat_x_imager.dat | scaercoef_mtsat_x_imager.dat | scaercoef_mtsat_x_imager_cams.dat |
| MVIRI | 7 / 8 | O3 / O3, CO2 | rtcoef_meteosat_x_mviri.dat | 05/10/2016 10/11/2016 | sccldcoef_meteosat_x_mviri.dat | scaercoef_meteosat_x_mviri.dat | scaercoef_meteosat_x_mviri_cams.dat |
| MVISR | 7 / 8 | O3 / O3, CO2 | rtcoef_fy1_x_mvisr.dat | 05/10/2016 10/11/2016 | sccldcoef_fy1_x_mvisr.dat | scaercoef_fy1_x_mvisr.dat | scaercoef_fy1_x_mvisr_cams.dat |
| PMR** 84L | 8 | O3, CO2 | rtcoef_nimbus_6_pmr.dat | 15/12/2016 | - | - | - |
| SEVIRI | 7 / 8 | O3 / O3, CO2 | rtcoef_msg_x_seviri.dat | 05/10/2016 10/11/2016 | sccldcoef_msg_x_seviri.dat | scaercoef_msg_x_seviri.dat | scaercoef_msg_x_seviri_cams.dat |
| SGLI | 7 / 8 | O3 / O3, CO2 | rtcoef_gcom-c_1_sgli.dat | 28/11/2016 | sccldcoef_gcom-c_1_sgli.dat | scaercoef_gcom-c_1_sgli.dat | scaercoef_gcom-c_1_sgli_cams.dat |
| SIRS / SIRS-BLUR | 7 / 8 | O3 / O3, CO2 | rtcoef_nimbus_4_sirs.dat rtcoef_nimbus_4_sirs-blur.dat | 24/09/2019 | - | - | - |
| SLSTR | 7 / 8 | O3 / O3, CO2 | rtcoef_sentinel3_x_slstr.dat | 05/10/2016 10/11/2016 11/07/2018 | sccldcoef_sentinel3_x_slstr.dat | scaercoef_sentinel3_x_slstr.dat | scaercoef_sentinel3_x_slstr_cams.dat |
| SSU 51L | 8 | O3, CO2 | rtcoef_noaa_xx_ssu.dat | 02/08/2012 09/08/2012 29/08/2012 | - | - | - |
| SSU 51L with variable cell pressure | 8 | O3, CO2 | rtcoef_noaa_xx_ssu_pmcshift.dat | 10/01/2013 | - | - | - |
| THIR | 7 / 8 | O3 / O3, CO2 | rtcoef_nimbus_x_thir.dat | 05/10/2016 10/11/2016 | sccldcoef_nimbus_x_thir.dat | scaercoef_nimbus_x_thir.dat | scaercoef_nimbus_x_thir_cams.dat |
| TIRS | 7 / 8 | O3 / O3, CO2 | rtcoef_landsat_8_tirs.dat | 05/10/2016 10/11/2016 | sccldcoef_landsat_8_tirs.dat | scaercoef_landsat_8_tirs.dat | scaercoef_landsat_8_tirs_cams.dat |
| TM | 7 / 8 | O3 / O3, CO2 | rtcoef_landsat_x_tm.dat | 05/10/2016 10/11/2016 | sccldcoef_landsat_x_tm.dat | scaercoef_landsat_x_tm.dat | scaercoef_landsat_x_tm_cams.dat |
| VIIRS | 7 / 8 | O3 / O3, CO2 | rtcoef_jpss_0_viirs.dat rtcoef_noaa_20_viirs.dat | 05/10/2016 10/11/2016 25/10/2017 | sccldcoef_jpss_0_viirs.dat sccldcoef_noaa_20_viirs.dat | scaercoef_jpss_0_viirs.dat scaercoef_noaa_20_viirs.dat | scaercoef_jpss_0_viirs_cams.dat scaercoef_noaa_20_viirs_cams.dat |
| VIMS | 7 / 8 | O3 / O3, CO2 | rtcoef_gf5_1_vims.dat | 23/08/2017 | sccldoef_gf5_1_vims.dat | scaercoef_gf5_1_vims.dat | scaercoef_gf5_1_vims_cams.dat |
| VIRR | 7 / 8 | O3 / O3, CO2 | rtcoef_fy3_3_virr.dat | 11/07/2019 | sccldcoef_fy3_3_virr.dat | scaercoef_fy3_3_virr.dat | scaercoef_fy3_3_virr_cams.dat |
| VISSR | 7 / 8 | O3 / O3, CO2 | rtcoef_fy2_x_vissr.dat | 05/10/2016 10/11/2016 24/03/2017 | sccldcoef_fy2_x_vissr.dat | scaercoef_fy2_x_vissr.dat | scaercoef_fy2_x_vissr_cams.dat |
| VTPR | 7 / 8 | O3 / O3, CO2 | rtcoef_noaa_x_vtpr1.dat | 05/10/2016 10/11/2016 | - | - | - |
* The ERS-1 ATSR coefficient file contains coefficients for 6 channels: 1-3 are the standard channels (12, 11, 3.7 microns respectively) and 4-6 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 6 channels in the rtcoef file.
** PMR coefficients are a special case: the zenith angle must be set to zero as the zenith angle is part of each channel definition. The CO2 profiles used for training the PMR coefficients are different to those used for other coefficients: see the coefficient file for the reference (background) profile and the profile min/max envelope.
NB “NOAA-5” is TIROS-N.
Visible/IR solar-compatible optical depth coefficients
All visible/IR solar coefficient files share these characteristics:
- Based on LBLRTM v12.2 line-by-line model
- 54 levels
- v9 predictors allowing variable O3 and CO2
- Coefficients are trained for zenith angles up to ~85 degrees for solar-affected channels (wavelengths below 5 microns) and all channels on GEO sensors
- Solar compatible
- Not NLTE compatible
- Not PC compatible
- Note that you can run IR-only simulations using these files, but you may find the v7 or v8 predictor files above give better results for IR channels.
- Channel numbering for IR channels may differ to the v7/v8 predictor files above: check the coefficient file headers, the user guide or the sensor tables page.
Downloads
- v9 predictor solar files VIS/NIR/IR instruments – extract to rtcoef_rttov12/rttov9pred54L/
- Cloud scattering coefficient files for all sensors – extract to rtcoef_rttov12/cldaer_visir/
- OPAC Aerosol scattering coefficient files for all sensors – extract to rtcoef_rttov12/cldaer_visir/
- CAMS Aerosol scattering coefficient files for all sensors – extract to rtcoef_rttov12/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.dat rtcoef_envisat_1_atsr.dat | 28/11/2016 | sccldcoef_ers_x_atsr.dat sccldcoef_envisat_1_atsr.dat | scaercoef_ers_x_atsr.dat scaercoef_envisat_1_atsr.dat | scaercoef_ers_x_atsr_cams.dat scaercoef_envisat_1_atsr_cams.dat |
| AATSR-shifted Info on AATSR 12 um anomaly | O3, CO2 | rtcoef_envisat_1_atsr-shifted.dat | 28/11/2016 | sccldcoef_envisat_1_atsr-shifted.dat | scaercoef_envisat_1_atsr-shifted.dat | scaercoef_envisat_1_atsr-shifted_cams.dat |
| ABI | O3, CO2 | rtcoef_goes_xx_abi.dat | 28/11/2016 | sccldcoef_goes_xx_abi.dat | scaercoef_goes_xx_abi.dat | scaercoef_goes_xx_abi_cams.dat |
| AGRI | O3, CO2 | rtcoef_fy4_1_agri.dat | 24/05/2018 | sccldcoef_fy4_1_agri.dat | scaercoef_fy4_1_agri.dat | scaercoef_fy4_1_agri_cams.dat |
| AHI | O3, CO2 | rtcoef_himawari_x_ahi.dat | 28/11/2016 | sccldcoef_himawari_x_ahi.dat | scaercoef_himawari_x_ahi.dat | scaercoef_himawari_x_ahi_cams.dat |
| AMI | O3, CO2 | rtcoef_gkompsat2_1_ami.dat | 15/10/2019 | sccldcoef_gkompsat2_1_ami.dat | scaercoef_gkompsat2_1_ami.dat | scaercoef_gkompsat2_1_ami_cams.dat |
| ASTER | O3, CO2 | rtcoef_eos_1_aster.dat | 28/11/2016 | sccldcoef_eos_1_aster.dat | scaercoef_eos_1_aster.dat | scaercoef_eos_1_aster_cams.dat |
| AVHRR | O3, CO2 | rtcoef_noaa_xx_avhrr.dat rtcoef_metop_x_avhrr.dat | 28/11/2016 13/11/2018 | sccldcoef_noaa_xx_avhrr.dat sccldcoef_metop_x_avhrr.dat | scaercoef_noaa_xx_avhrr.dat scaercoef_metop_x_avhrr.dat | scaercoef_noaa_xx_avhrr_cams.dat scaercoef_metop_x_avhrr_cams.dat |
| EPIC | O3 | rtcoef_dscovr_1_epic.dat | 12/05/2020 | sccldcoef_dscovr_1_epic.dat | scaercoef_dscovr_1_epic.dat | scaercoef_dscovr_1_epic_cams.dat |
| FCI | O3, CO2 | rtcoef_mtg_1_fci.dat | 04/01/2017 | sccldcoef_mtg_1_fci.dat | scaercoef_mtg_1_fci.dat | scaercoef_mtg_1_fci_cams.dat |
| GMS imager | O3, CO2 | rtcoef_gms_x_imager.dat | 02/03/2017 | sccldcoef_gms_x_imager.dat | scaercoef_gms_x_imager.dat | scaercoef_gms_x_imager_cams.dat |
| GOES imager | O3, CO2 | rtcoef_goes_xx_imager.dat | 28/11/2016 | sccldcoef_goes_xx_imager.dat | scaercoef_goes_xx_imager.dat | scaercoef_goes_xx_imager_cams.dat |
| HRIR | O3, CO2 | rtcoef_nimbus_x_hrir.dat | 14/10/2019 15/10/2019 | - | - | - |
| INSAT-3D(R) imager | O3, CO2 | rtcoef_insat_x_imager.dat | 28/11/2016 | sccldcoef_insat_x_imager.dat | scaercoef_insat_x_imager.dat | scaercoef_insat_x_imager_cams.dat |
| IRAS | O3, CO2 | rtcoef_fy3_1_iras.dat | 28/11/2016 | sccldcoef_fy3_1_iras.dat | scaercoef_fy3_1_iras.dat | scaercoef_fy3_1_iras_cams.dat |
| LI** | O3, CO2 | rtcoef_mtg_1_li.dat | 25/01/2017 | - | - | - |
| MERSI-2 | O3, CO2 | rtcoef_fy3_4_mersi2.dat | 04/03/2019 | sccldcoef_fy3_4_mersi2.dat | scaercoef_fy3_4_mersi2.dat | scaercoef_fy3_4_mersi2_cams.dat |
| MetImage | O3, CO2 | rtcoef_metopsg_1_metimage.dat | 19/05/2020 | sccldcoef_metopsg_1_metimage.dat | scaercoef_metopsg_1_metimage.dat | scaercoef_metopsg_1_metimage_cams.dat |
| MI | O3, CO2 | rtcoef_coms_1_mi.dat | 16/10/2017 | sccldcoef_coms_1_mi.dat | scaercoef_coms_1_mi.dat | scaercoef_coms_1_mi_cams.dat |
| MODIS | O3, CO2 | rtcoef_eos_x_modis.dat | 28/11/2016 | sccldcoef_eos_x_modis.dat | scaercoef_eos_x_modis.dat | scaercoef_eos_x_modis_cams.dat |
| MODIS shifted spectral response | O3, CO2 | rtcoef_eos_x_modis-shifted.dat | 28/11/2016 | sccldcoef_eos_x_modis-shifted.dat | scaercoef_eos_x_modis-shifted.dat | scaercoef_eos_x_modis-shifted_cams.dat |
| MRIR | O3, CO2 | rtcoef_nimbus_2_mrir.dat | 24/09/2019 | - | - | - |
| MSI | O3, CO2 | rtcoef_sentinel2_x_msi.dat | 12/05/2020 | sccldcoef_sentinel2_x_msi.dat | scaercoef_sentinel2_x_msi.dat | scaercoef_sentinel2_x_msi_cams.dat |
| MSUGS | O3, CO2 | rtcoef_electro-l_2_msugs.dat | 25/11/2019 | sccldcoef_electro-l_2_msugs.dat | scaercoef_electro-l_2_msugs.dat | scaercoef_electro-l_2_msugs_cams.dat |
| MSUMR | O3, CO2 | rtcoef_meteor-m_2_msumr.dat | 27/08/2018 | sccldcoef_meteor-m_2_msumr.dat | scaercoef_meteor-m_2_msumr.dat | scaercoef_meteor-m_2_msumr_cams.dat |
| MTSAT imager | O3, CO2 | rtcoef_mtsat_x_imager.dat | 28/11/2016 | sccldcoef_mtsat_x_imager.dat | scaercoef_mtsat_x_imager.dat | scaercoef_mtsat_x_imager_cams.dat |
| OLCI*** | O3, CO2 | rtcoef_sentinel3_x_olci.dat | 06/01/2017 07/05/2020 | - | - | - |
| OLI | O3, CO2 | rtcoef_landsat_8_oli.dat | 28/11/2016 | sccldcoef_landsat_8_oli.dat | scaercoef_landsat_8_oli.dat | scaercoef_landsat_8_oli_cams.dat |
| SEVIRI**** | O3 | rtcoef_msg_x_seviri_o3.dat | 28/11/2016 | sccldcoef_msg_x_seviri.dat | scaercoef_msg_x_seviri.dat | scaercoef_msg_x_seviri_cams.dat |
| SEVIRI | O3, CO2 | rtcoef_msg_x_seviri.dat | 28/11/2016 | As above | As above | As above |
| SLSTR | O3, CO2 | rtcoef_sentinel3_x_slstr.dat | 28/11/2016 11/07/2018 | sccldcoef_sentinel3_x_slstr.dat | scaercoef_sentinel3_x_slstr.dat | scaercoef_sentinel3_x_slstr_cams.dat |
| VIIRS | O3, CO2 | rtcoef_jpss_0_viirs.dat rtcoef_noaa_20_viirs.dat | 28/11/2016 25/10/2017 | sccldcoef_jpss_0_viirs.dat sccldcoef_noaa_20_viirs.dat | scaercoef_jpss_0_viirs.dat scaercoef_noaa_20_viirs.dat | scaercoef_jpss_0_viirs_cams.dat scaercoef_noaa_20_viirs_cams.dat |
| VIRR | O3, CO2 | rtcoef_fy3_3_virr.dat | 11/07/2019 | sccldcoef_fy3_3_virr.dat | scaercoef_fy3_3_virr.dat | scaercoef_fy3_3_virr_cams.dat |
| VISSR | O3, CO2 | rtcoef_fy2_x_vissr.dat | 28/11/2016 | sccldcoef_fy2_x_vissr.dat | scaercoef_fy2_x_vissr.dat | scaercoef_fy2_x_vissr_cams.dat |
* 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.
**** The variable O3+CO2 SEVIRI coefficients exhibit larger errors in reproducing the LBL data in channel 4 (3.9µm) so O3-only SEVIRI coefficients are also available.
MFASIS LUT files for visible cloud simulations
The MFASIS LUTs must be used alongside the visible/IR rtcoef and sccldcoef files listed in the table above. MFASIS LUTs are trained using either the OPAC cloud liquid water (CLW) properties or the “Deff” CLW properties. All LUTs are trained using the SSEC/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.
NB MFASIS is only available in RTTOV v12.2 and later versions. RTTOV v12.2 users should download the MFASIS bug fix dated 30/10/2018 available on the bug fix/code updates page before using the LUT files below. RTTOV v12.3 includes this updated code.
RTTOV v12.3 introduced a new water vapour correction which reduces the errors in the SEVIRI 0.8um channel to the same magnitude as other channels. All MFASIS LUT files were updated with the release of v12.3: for ABI and AHI there is no change in outputs, and the new files are compatible with both v12.2 and v12.3. For SEVIRI, the v12.2 files remain available and can be used with RTTOV v12.3. The v12.3 SEVIRI files are considerably larger because they include the additional data required for the water vapour correction: these files cannot be used with RTTOV v12.2. Also note that there were some updates to the LUT generation process after the v12.2 SEVIRI files were generated which means that the 0.6um channel simulations are not identical for the v12.2 and v12.3 SEVIRI files.
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 below 1 micron.
- This document gives information on the errors in the MFASIS parameterisation in RTTOV v12.2 by showing histograms of the differences between MFASIS and the multiple-scattering simulations used to train the LUTs.
- This document shows the reduction in errors for the SEVIRI 0.8um channel with the variable water vapour introduced in RTTOV v12.3.
- Download required files to rtcoef_rttov12/mfasis_lut/
See below for information about cloud optical property files.
| Sensor | Associated rtcoef filename | Associated cloud coef filename | MFASIS LUT file: OPAC CLW | Date of OPAC CLW file creation | MFASIS LUT file: Deff CLW | Date of Deff CLW file creation |
|---|---|---|---|---|---|---|
| ABI (RTTOV v12.2 and v12.3) | rtcoef_goes_16_abi.dat rtcoef_goes_17_abi.dat | sccldcoef_goes_16_abi.dat sccldcoef_goes_17_abi.dat | rttov_mfasis_cld_goes_16_abi_opac.H5 rttov_mfasis_cld_goes_17_abi_opac.H5 | 07/10/2018 07/10/2018 | rttov_mfasis_cld_goes_16_abi_deff.H5 rttov_mfasis_cld_goes_17_abi_deff.H5 | 11/10/2018 11/10/2018 |
| AHI (RTTOV v12.2 and v12.3) | rtcoef_himawari_8_ahi.dat rtcoef_himawari_9_ahi.dat | sccldcoef_himawari_8_ahi.dat sccldcoef_himawari_9_ahi.dat | rttov_mfasis_cld_himawari_8_ahi_opac.H5 rttov_mfasis_cld_himawari_9_ahi_opac.H5 | 21/09/2018 25/09/2018 | rttov_mfasis_cld_himawari_8_ahi_deff.H5 rttov_mfasis_cld_himawari_9_ahi_deff.H5 | 11/10/2018 11/10/2018 |
| SEVIRI (RTTOV v12.2 and v12.3) | rtcoef_msg_3_seviri*.dat rtcoef_msg_4_seviri*.dat | sccldcoef_msg_3_seviri.dat sccldcoef_msg_4_seviri.dat | rttov_mfasis_cld_msg_3_seviri_opac_v12.2.H5 rttov_mfasis_cld_msg_4_seviri_opac_v12.2.H5 | 06/09/2018 12/09/2018 | rttov_mfasis_cld_msg_3_seviri_deff_v12.2.H5 rttov_mfasis_cld_msg_4_seviri_deff_v12.2.H5 | 07/09/2018 27/09/2018 |
| SEVIRI with WV correction (RTTOV v12.3 only) | 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 | 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 | 12/08/2019 18/08/2019 24/01/2019 29/01/2019 | 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 | 11/08/2019 17/08/2019 27/12/2018 23/01/2019 |
MW optical depth coefficients
All MW sensor coefficient files share these characteristics:
- Based on Liebe 89/92 LbL model
- All on 54 levels except for the Zeeman files
- v7 predictors
- No Planck-weighted channels
- No optional trace gases
- Cloud liquid water is an optional input for “clear-sky” (non-RTTOV-SCATT) simulations (treated as an absorbing medium)
- Not solar compatible
- Not NLTE compatible
- Not PC compatible
Downloads
- Files including band-correction coefficients – extract to rtcoef_rttov12/rttov7pred54L/. Band-correction coefficients are included for all sensors though in some cases they have very little impact. For those instruments where they do have a significant impact on radiances, the impact of the band corrections on brightness temperatures is negligible.
- It is recommended to use the MW coefficient files including band-correction coefficients. However, please contact the NWP SAF Helpdesk if you require MW coefficients excluding band-correction coefficients.
- RTTOV-SCATT Mietable files are linked in the table below – extract to rtcoef_rttov12/mietable/ (NB these were updated in April 2018 – see notes below)
Note: the optical property tables used by RTTOV-SCATT have historically been called “Mie tables”. This convention has become misleading as not all particles are treated as Mie spheres, in particular the optical properties for solid precipitation are based on non-spherical particles.
| Sensor | Zeeman compatible | Filename | Date of rtcoef file creation | Associated Mietable filename | Date of Mietable file creation |
|---|---|---|---|---|---|
| AltiKa | N | rtcoef_saral_1_altika.dat | 24/05/2017 | mietable_saral_altika.dat | 26/03/2018 |
| AMR | N | rtcoef_jason_2_amr.dat | 24/05/2017 | - | |
| AMR-C | N | rtcoef_jasoncs_1_amrc.dat | 20/11/2019 | - | |
| AMSR-E | N | rtcoef_eos_2_amsre.dat | 24/05/2017 | mietable_eos_amsre.dat | 26/03/2018 |
| AMSR2 | N | rtcoef_gcom-w_1_amsr2.dat | 24/05/2017 | mietable_gcom-w_amsr2.dat | 26/03/2018 |
| AMSU-A | N | rtcoef_noaa_xx_amsua.dat rtcoef_metop_x_amsua.dat rtcoef_eos_2_amsua.dat | 24/05/2017 | mietable_noaa_amsua.dat mietable_metop_amsua.dat (rename/copy noaa file) mietable_eos_amsua.dat (rename/copy noaa file) | 26/03/2018 |
| AMSU-B | N | rtcoef_noaa_xx_amsub.dat | 24/05/2017 | mietable_noaa_amsub.dat | 26/03/2018 |
| ATMS | N | rtcoef_jpss_0_atms.dat rtcoef_noaa_20_atms.dat | 29/01/2018 | mietable_jpss_atms.dat mietable_noaa_atms.dat (rename/copy jpss file) | 26/03/2018 |
| COWVR | N | rtcoef_ors_6_cowvr.dat | 24/05/2017 | - | |
| CPR | N | rtcoef_cloudsat_1_cpr.dat | 09/05/2018 | - | |
| DPR | N | rtcoef_gpm_1_dpr.dat | 26/02/2020 | - | |
| GEMS1 | N | rtcoef_oms_1_gems1.dat | 23/11/2020 | - | |
| GMI | N | rtcoef_gpm_1_gmi.dat | 24/05/2017 | mietable_gpm_gmi.dat | 26/03/2018 |
| HSB | N | rtcoef_eos_2_hsb.dat | 24/05/2017 | - | |
| ICI* | N | rtcoef_metopsg_1_ici.dat | 24/05/2017 | mietable_metopsg_ici.dat | 26/03/2018 |
| MADRAS | N | rtcoef_meghatr_1_madras.dat | 24/05/2017 | mietable_meghatr_madras.dat | 26/03/2018 |
| MIRAS | N | rtcoef_smos_1_miras.dat | 24/05/2017 | - | |
| MHS | N | rtcoef_noaa_xx_mhs.dat rtcoef_metop_x_mhs.dat | 24/05/2017 | mietable_noaa_mhs.dat mietable_metop_mhs.dat (rename/copy noaa file) | 26/03/2018 |
| MSU | N | rtcoef_noaa_xx_msu.dat | 24/05/2017 | - | |
| MTVZA-GY | N | rtcoef_meteor-m_2_mtvzagy.dat | 24/05/2017 | mietable_meteor-m_mtvzagy.dat | 22/05/2020 |
| MWHS | N | rtcoef_fy3_x_mwhs.dat | 24/05/2017 | mietable_fy3_mwhs.dat | 26/03/2018 |
| MWHS2 | N | rtcoef_fy3_x_mwhs2.dat | 10/08/2018 | mietable_fy3_mwhs2.dat | 26/03/2018 |
| MWI | N | rtcoef_metopsg_1_mwi.dat | 24/05/2017 | mietable_metopsg_mwi.dat | 26/03/2018 |
| MWR | N | rtcoef_ers_x_mwr.dat rtcoef_envisat_1_mwr.dat rtcoef_sentinel3_1_mwr.dat | 24/05/2017 23/03/2020 | mietable_ers_mwr.dat mietable_envisat_mwr.dat (rename/copy ers file) mietable_sentinel3_mwr.dat (rename/copy ers file) | 26/03/2018 |
| FY3 MWRI | N | rtcoef_fy3_x_mwri.dat | 24/05/2017 | mietable_fy3_mwri.dat | 26/03/2018 |
| HY2 MWRI | N | rtcoef_hy2_1_hy2mwri.dat | 26/02/2020 | - | |
| MWS | N | rtcoef_metopsg_1_mws.dat | 05/12/2019 | mietable_metopsg_mws.dat | 26/03/2018 |
| MWTS | N | rtcoef_fy3_x_mwts.dat | 24/05/2017 | mietable_fy3_mwts.dat | 26/03/2018 |
| MWTS2 | N | rtcoef_fy3_x_mwts2.dat | 10/08/2018 | mietable_fy3_mwts2.dat | 26/03/2018 |
| SAPHIR | N | rtcoef_meghatr_1_saphir.dat | 24/05/2017 | mietable_meghatr_saphir.dat | 26/03/2018 |
| SCAMS | N | rtcoef_nimbus_6_scams.dat | 25/05/2017 | - | |
| SMMR | N | rtcoef_nimbus_7_smmr.dat | 24/05/2017 | - | |
| SSM/I | N | rtcoef_dmsp_xx_ssmi.dat | 24/05/2017 | mietable_dmsp_ssmi.dat | 26/03/2018 |
| SSMIS | N | rtcoef_dmsp_xx_ssmis.dat | 24/05/2017 | mietable_dmsp_ssmis.dat | 26/03/2018 |
| SSMIS Zeeman (84L) | Y | rtcoef_dmsp_xx_ssmis_zeeman.dat | 11/01/2017 | As above | |
| SSM/T2 | N | rtcoef_dmsp_xx_ssmt2.dat | 24/05/2017 | mietable_dmsp_ssmt2.dat | 26/02/2020 |
| TMI | N | rtcoef_trmm_1_tmi.dat | 24/05/2017 | mietable_trmm_tmi.dat | 26/03/2018 |
| TROPICS | N | rtcoef_tropics_0_tropics.dat | 24/10/2017 | mietable_tropics_tropics.dat | 26/03/2018 |
| Windsat | N | rtcoef_coriolis_1_windsat.dat | 24/05/2017 | mietable_coriolis_windsat.dat | 26/03/2018 |
* ICI coefficients are preliminary: channel specifications may change. Work is planned to validate the spectroscopic data used at frequencies above 200GHz. The ICI mietable is generated in an identical manner to those for other instruments except as regards the scattering properties for snow particles. The ICI Mie table uses the Eriksson et al. (2018) sector snowflake (i.e. from the ARTS database) rather than the normal Liu (2008) version. This is because only the ARTS database has optical properties available at all ICI frequencies. Be aware that, at frequencies that are represented in both databases, there are small differences in the sector snowflake optical properties between the two databases. These differences are equivalent to several Kelvin in brightness temperature in deep convective areas.
NB “NOAA-5” is TIROS-N.
Updated Mie tables (April 2018)
Based on results from experiments carried out at ECMWF (Lonitz and Geer, 2018) the Mietable files have been updated using the Rosenkranz (2015) liquid water permittivity parameterisation which affects the cloud liquid water and rain hydrometeor types.
Note that these updated Mietable files will result in different output for the RTTOV-SCATT tests to the reference data provided in the RTTOV v12.2 package. Updated test reference data are available to download on the code updates page.
Updated Mie tables (September 2013)
The original RTTOV-SCATT Mie coefficients produced unrealistically high amounts of scattering from snow hydrometeors at 30-50 GHz and insufficient scattering at 150-183 GHz. The new coefficients address this problem by representing snow hydrometeors as three-dimensional snowflakes rather than Mie spheres. While it is possible to improve Mie sphere results by tuning the snow particle density, it is difficult to improve results at all frequencies simultaneously. The new snow hydrometeor optical properties are based on the “sector snowflake” from the Liu (2008) database of discrete dipole computations for nonspherical ice particles. The new particle shape was chosen because it produces the best fit between observations and ECMWF simulations across frequencies from 10 to 183 GHz.
References:
- 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 Discuss., https://doi.org/10.5194/essd-2018-23, in review.
- 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
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., Remy, S., Benedetti, A., Flemming, J., Bechtold, P., Rodwell, M.J., Morcrette, J.J., 2017: Implementation of a CAMS-based aerosol climatology in the IFS. ECMWF Technical Memorandum 801
Cloud optical property files
As of RTTOV v12.2 there are two options for predefined cloud liquid water (CLW) optical properties and two options 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 were introduced in RTTOV v9 and 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.
All sccldcoef files contain these optical properties. MFASIS LUT files are available trained with these optical properties.
Deff CLW scheme
These optical properties were introduced in RTTOV v12.2. They 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). For these properties the cloud effective diameter must be explicitly provided in the profiles(:)%clwde(1:nlayers) array.
All sccldcoef files contain these optical properties except for IASI-NG (if you require these properties for IASI-NG please request this via the NWP SAF Helpdesk). MFASIS LUT files are available trained with these optical properties.
SSEC/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(:)%idg 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 scheme
These optical properties are parameterised in terms of ice water content and temperature. 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 idg and icede profile variables are ignored.
The data for this parameterisation are stored in the code rather than in external files. MFASIS is not currently compatible with this ice scheme.
Reference profiles and regression limits
RTTOV
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 predictor version of the coefficient file determines which other gases may optionally be supplied:
- v7 predictors: O3
- v8 predictors: O3 and CO2
- v9 predictors: O3, CO2, CO, N2O, CH4 and SO2
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 the RTTOV v12 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 RTTOV v11 (and earlier) coefficient files contain the stretched limits: despite this difference the behaviour of RTTOV v12 is the same as v11 in respect of the profile limits.
PC-RTTOV
As of RTTOV v12.2 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.