RTTOV Coefficient File Downloads

RTTOV v12 Coefficient File Downloads

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/
SensorLevelsPredictors versionTrace gasesSolar?NLTE?FilenameDate of file creationAssociated aerosol
coef filename
Associated cloud
coef filename
AIRS547O3NNrtcoef_eos_2_airs.H514/10/2016scaercoef_eos_2_airs.H5
scaercoef_eos_2_airs_chou-only.H5
sccldcoef_eos_2_airs.H5
sccldcoef_eos_2_airs_chou-only.H5
AIRS1017O3NNrtcoef_eos_2_airs.H503/10/2016As aboveAs above
AIRS1018O3, CO2NNrtcoef_eos_2_airs.H503/10/2016As aboveAs above
AIRS1019O3, CO2, CO, N2O, CH4YNrtcoef_eos_2_airs.H503/11/2016As aboveAs above
AIRS1019O3, CO2, CO, N2O, CH4, SO2YNrtcoef_eos_2_airs_so2.H521/11/2016As aboveAs above
CrIS547O3NNrtcoef_jpss_0_cris.H514/10/2016scaercoef_jpss_0_cris.H5
scaercoef_jpss_0_cris_chou-only.H5
sccldcoef_jpss_0_cris.H5
sccldcoef_jpss_0_cris_chou-only.H5
CrIS1017O3NNrtcoef_jpss_0_cris.H503/10/2016As aboveAs above
CrIS1018O3, CO2NNrtcoef_jpss_0_cris.H503/10/2016As aboveAs above
CrIS1019O3, CO2, CO, N2O, CH4YNrtcoef_jpss_0_cris.H503/11/2016As aboveAs above
CrIS1019O3, CO2, CO, N2O, CH4, SO2YNrtcoef_jpss_0_cris_so2.H521/11/2016As aboveAs above
CrIS FSR547O3NNrtcoef_jpss_0_cris-fsr.H514/10/2016scaercoef_jpss_0_cris-fsr.H5
scaercoef_jpss_0_cris-fsr_chou-only.H5
sccldcoef_jpss_0_cris-fsr.H5
sccldcoef_jpss_0_cris-fsr_chou-only.H5
CrIS FSR1017O3NNrtcoef_jpss_0_cris-fsr.H503/10/2016As aboveAs above
CrIS FSR1018O3, CO2NNrtcoef_jpss_0_cris-fsr.H503/10/2016As aboveAs above
CrIS FSR1019O3, CO2, CO, N2O, CH4YNrtcoef_jpss_0_cris-fsr.H503/11/2016As aboveAs above
CrIS FSR1019O3, CO2, CO, N2O, CH4, SO2YNrtcoef_jpss_0_cris-fsr_so2.H521/11/2016As aboveAs above
IASI547O3NYrtcoef_metop_2_iasi.H514/10/2016scaercoef_metop_2_iasi.H5
scaercoef_metop_2_iasi_chou-only.H5
sccldcoef_metop_2_iasi.H5
sccldcoef_metop_2_iasi_chou-only.H5
IASI1017O3NYrtcoef_metop_2_iasi.H503/10/2016As aboveAs above
IASI1018O3, CO2NYrtcoef_metop_2_iasi.H503/10/2016As aboveAs above
IASI1019O3, CO2, CO, N2O, CH4YYrtcoef_metop_2_iasi.H505/12/2016As aboveAs above
IASI1019O3, CO2, CO, N2O, CH4, SO2YYrtcoef_metop_2_iasi_so2.H517/03/2017As aboveAs above
IASI-NG1017O3NNrtcoef_metopsg_1_iasing.H503/10/2016scaercoef_metopsg_1_iasing.H5
scaercoef_metopsg_1_iasing_chou-only.H5
sccldcoef_metopsg_1_iasing.H5
sccldcoef_metopsg_1_iasing_chou-only.H5
IASI-NG1018O3, CO2NNrtcoef_metopsg_1_iasing.H503/10/2016As aboveAs above
IASI-NG1019O3, CO2, CO, N2O, CH4YNrtcoef_metopsg_1_iasing.H505/12/2016As aboveAs above
IASI-NG1019O3, CO2, CO, N2O, CH4, SO2YNrtcoef_metopsg_1_iasing_so2.H517/03/2017As aboveAs above
IRFS2547O3NNrtcoef_meteor-m_2_irfs2.H514/10/2016--
IRFS21017O3NNrtcoef_meteor-m_2_irfs2.H503/10/2016--
IRFS21018O3, CO2NNrtcoef_meteor-m_2_irfs2.H503/10/2016--
IRFS21019O3, CO2, CO, N2O, CH4YNrtcoef_meteor-m_2_irfs2.H503/11/2016--
IRFS21019O3, CO2, CO, N2O, CH4, SO2YNrtcoef_meteor-m_2_irfs2_so2.H521/11/2016--
IRIS1018O3, CO2NNrtcoef_nimbus_4_iris.H513/11/2016--
MRFIRS547O3NNrtcoef_clarreo_1_mrfirs.H501/03/2017--
MRFIRS548O3, CO2NNrtcoef_clarreo_1_mrfirs.H501/03/2017--
SI1018O3, CO2NNrtcoef_meteor_25_si.H503/10/2016--

Metop-B IASI coefficients

The Metop-B (i.e. metop_1) IASI optical depth coefficient file is identical to the Metop-A (metop_2) coefficient file except that the satellite ID is 1 (for Metop-B) instead of 2 (for Metop-A). The IASI cloud/aerosol scattering and PC coefficient files are identical for Metop-A and Metop-B.

MTG-IRS coefficients

Experimental MTG-IRS coefficients have been generated using transmittances from simulated IASI spectra. Coefficients are available with a Hamming apodisation function and with a “COSCAR” apodisation function (a value of 1.0 over 0-90% of the max OPD and decays to zero at 100% following a cosine, representing “light” apodisation). You should be careful when using the COSCAR coefficients as the errors in the optical depth prediction scheme are larger due to the light apodisation. 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):

  • Hamming apodisation, v7 predictors 101L – NB these coefficients are currently being regenerated using the latest training data and will be available soon
  • COSCAR apodisation, v7 predictors 101L
SensorLevelsPredictors versionTrace gasesNLTE?FilenameDate of file creation
MTG-IRS COSCAR apodisation547O3Nrtcoef_mtg_1_irs-apodcoscar.H514/10/2016
MTG-IRS COSCAR apodisation1017O3Nrtcoef_mtg_1_irs-apodcoscar.H503/10/2016

PC-RTTOV coefficients

Currently PC 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. PC-RTTOV currently allows only O3 and CO2 to vary in the simulations (see the user guide).

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

The predictor channel selection for a given PC coefficient file 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/
SensorTrace gases for PCNLTE
for PC?
Surface types for PCOptical depth coef filenameDate of rtcoef file creationPC coef filename
AIRSO3, CO2Nland, seartcoef_eos_2_airs_pcrttov_compat.H501/02/2014pccoef_eos_2_airs_landsea.H5
IASIO3, CO2Yland, seartcoef_metop_2_iasi_pcrttov_compat.H502/09/2016pccoef_metop_2_iasi_landsea_nlte.H5
IASI-NGO3, CO2Nsea-onlyrtcoef_metopsg_1_iasing_pcrttov_compat.H501/02/2014pccoef_metopsg_1_iasing_sea.H5

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)
  • 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

SensorPredictors versionTrace gasesFilenameDate of file creationAssociated aerosol coef filenameAssociated cloud coef filename
(A)ATSR*7 / 8O3 / O3, CO2rtcoef_ers_x_atsr.dat
rtcoef_envisat_1_atsr.dat
05/10/2016
10/11/2016
scaercoef_ers_x_atsr.dat
scaercoef_envisat_1_atsr.dat
sccldcoef_ers_x_atsr.dat
sccldcoef_envisat_1_atsr.dat
AATSR-shifted
Info on AATSR 12 um anomaly
7 / 8O3 / O3, CO2rtcoef_envisat_1_atsr-shifted.dat05/10/2016
10/11/2016
scaercoef_envisat_1_atsr-shifted.datsccldcoef_envisat_1_atsr-shifted.dat
ABI7 / 8O3 / O3, CO2rtcoef_goes_xx_abi.dat05/10/2016
10/11/2016
scaercoef_goes_xx_abi.datsccldcoef_goes_xx_abi.dat
AHI7 / 8O3 / O3, CO2rtcoef_himawari_x_ahi.dat05/10/2016
10/11/2016
scaercoef_himawari_x_ahi.datsccldcoef_himawari_x_ahi.dat
ASTER7 / 8O3 / O3, CO2rtcoef_eos_1_aster.dat05/10/2016
10/11/2016
scaercoef_eos_1_aster.datsccldcoef_eos_1_aster.dat
AVHRR7 / 8O3 / O3, CO2rtcoef_noaa_xx_avhrr.dat
rtcoef_metop_x_avhrr.dat
05/10/2016
10/11/2016
scaercoef_noaa_xx_avhrr.dat
scaercoef_metop_x_avhrr.dat
scaercoef_noaa_xx_avhrr.dat
scaercoef_metop_x_avhrr.dat
ECOSTRESS7 / 8O3 / O3, CO2rtcoef_iss_1_ecostres.dat05/10/2016
10/11/2016
scaercoef_iss_1_ecostres.datsccldcoef_iss_1_ecostres.dat
FCI7 / 8O3 / O3, CO2rtcoef_mtg_1_fci.dat04/01/2017scaercoef_mtg_1_fci.datsccldcoef_mtg_1_fci.dat
GMS imager7 / 8O3 / O3, CO2rtcoef_gms_x_imager.dat01/03/2017
02/03/2017
scaercoef_gms_x_imager.datsccldcoef_gms_x_imager.dat
GOES imager7 / 8O3 / O3, CO2rtcoef_goes_xx_imager.dat05/10/2016
10/11/2016
scaercoef_goes_xx_imager.datsccldcoef_goes_xx_imager.dat
GOES sounder7 / 8O3 / O3, CO2rtcoef_goes_xx_sounder.dat05/10/2016
10/11/2016
scaercoef_goes_xx_sounder.datsccldcoef_goes_xx_sounder.dat
HIRS7 / 8O3 / O3, CO2rtcoef_noaa_xx_hirs.dat
rtcoef_metop_x_hirs.dat
rtcoef_nimbus_6_hirs.dat
05/10/2016
10/11/2016
scaercoef_noaa_xx_hirs.dat
scaercoef_metop_x_hirs.dat
scaercoef_nimbus_6_hirs.dat
sccldcoef_noaa_xx_hirs.dat
sccldcoef_metop_x_hirs.dat
sccldcoef_nimbus_6_hirs.dat
HIRS shifted
spectral response
7 / 8O3 / O3, CO2rtcoef_noaa_xx_hirs-shifted.dat
rtcoef_metop_x_hirs-shifted.dat
17/05/2017
18/05/2017
19/05/2017
scaercoef_noaa_xx_hirs-shifted.dat
scaercoef_metop_x_hirs-shifted.dat
sccldcoef_noaa_xx_hirs-shifted.dat
sccldcoef_metop_x_hirs-shifted.dat
IIR7 / 8O3 / O3, CO2rtcoef_calipso_1_iir.dat05/10/2016
10/11/2016
scaercoef_calipso_1_iir.datsccldcoef_calipso_1_iir.dat
INSAT-3D(R) imager7 / 8O3 / O3, CO2rtcoef_insat3_x_imager.dat05/10/2016
10/11/2016
scaercoef_insat3_x_imager.datsccldcoef_insat3_x_imager.dat
INSAT-3D(R) sounder7 / 8O3 / O3, CO2rtcoef_insat3_x_sounder.dat05/10/2016
10/11/2016
13/11/2016
scaercoef_insat3_x_sounder.datsccldcoef_insat3_x_sounder.dat
IRAS7 / 8O3 / O3, CO2rtcoef_fy3_1_iras.dat05/10/2016
10/11/2016
scaercoef_fy3_1_iras.datsccldcoef_fy3_1_iras.dat
IRMSS7 / 8O3 / O3, CO2rtcoef_hj1_2_irmss.dat05/10/2016
10/11/2016
scaercoef_hj1_2_irmss.datsccldcoef_hj1_2_irmss.dat
MBFIRI7 / 8O3 / O3, CO2rtcoef_ticfire_1_mbfiri.dat16/11/2016scaercoef_ticfire_1_mbfiri.datsccldcoef_ticfire_1_mbfiri.dat
MERSI-17 / 8O3 / O3, CO2rtcoef_fy3_3_mersi1.dat05/10/2016
10/11/2016
scaercoef_fy3_3_mersi1.datsccldcoef_fy3_3_mersi1.dat
MetImage7 / 8O3 / O3, CO2rtcoef_metopsg_1_metimage.dat05/10/2016
10/11/2016
scaercoef_metopsg_1_metimage.datsccldcoef_metopsg_1_metimage.dat
MI7 / 8O3 / O3, CO2rtcoef_coms_1_mi.dat05/10/2016
10/11/2016
scaercoef_coms_1_mi.datsccldcoef_coms_1_mi.dat
MODIS7 / 8O3 / O3, CO2rtcoef_eos_x_modis.dat28/11/2016scaercoef_eos_x_modis.datsccldcoef_eos_x_modis.dat
MODIS shifted
spectral response
7 / 8O3 / O3, CO2rtcoef_eos_x_modis-shifted.dat28/11/2016scaercoef_eos_x_modis-shifted.datsccldcoef_eos_x_modis-shifted.dat
MRIR7 / 8O3 / O3, CO2rtcoef_nimbus_3_mrir.dat05/10/2016
10/11/2016
scaercoef_nimbus_3_mrir.datsccldcoef_nimbus_3_mrir.dat
MSUMR7 / 8O3 / O3, CO2rtcoef_meteor-m_1_msumr.dat05/10/2016
10/11/2016
scaercoef_meteor-m_1_msumr.datsccldcoef_meteor-m_1_msumr.dat
MTSAT imager7 / 8O3 / O3, CO2rtcoef_mtsat_x_imager.dat05/10/2016
10/11/2016
scaercoef_mtsat_x_imager.datsccldcoef_mtsat_x_imager.dat
MVIRI7 / 8O3 / O3, CO2rtcoef_meteosat_x_mviri.dat05/10/2016
10/11/2016
scaercoef_meteosat_x_mviri.datsccldcoef_meteosat_x_mviri.dat
MVISR7 / 8O3 / O3, CO2rtcoef_fy1_x_mvisr.dat05/10/2016
10/11/2016
scaercoef_fy1_x_mvisr.datsccldcoef_fy1_x_mvisr.dat
PMR** 84L8O3, CO2rtcoef_nimbus_6_pmr.dat15/12/2016--
SEVIRI7 / 8O3 / O3, CO2rtcoef_msg_x_seviri.dat05/10/2016
10/11/2016
scaercoef_msg_x_seviri.datsccldcoef_msg_x_seviri.dat
SGLI7 / 8O3 / O3, CO2rtcoef_gcom-c_1_sgli.dat28/11/2016scaercoef_gcom-c_1_sgli.datsccldcoef_gcom-c_1_sgli.dat
SLSTR7 / 8O3 / O3, CO2rtcoef_sentinel3_1_slstr.dat05/10/2016
10/11/2016
scaercoef_sentinel3_1_slstr.datsccldcoef_sentinel3_1_slstr.dat
SSU 51L8O3, CO2rtcoef_noaa_xx_ssu.dat02/08/2012
09/08/2012
29/08/2012
--
SSU 51L with variable
cell pressure
8O3, CO2rtcoef_noaa_xx_ssu_pmcshift.dat10/01/2013--
THIR7 / 8O3 / O3, CO2rtcoef_nimbus_x_thir.dat05/10/2016
10/11/2016
scaercoef_nimbus_x_thir.datsccldcoef_nimbus_x_thir.dat
TIRS7 / 8O3 / O3, CO2rtcoef_landsat_8_tirs.dat05/10/2016
10/11/2016
scaercoef_landsat_8_tirs.datsccldcoef_landsat_8_tirs.dat
TM7 / 8O3 / O3, CO2rtcoef_landsat_x_tm.dat05/10/2016
10/11/2016
scaercoef_landsat_x_tm.datsccldcoef_landsat_x_tm.dat
VIIRS7 / 8O3 / O3, CO2rtcoef_jpss_0_viirs.dat05/10/2016
10/11/2016
scaercoef_jpss_0_viirs.datsccldcoef_jpss_0_viirs.dat
VISSR7 / 8O3 / O3, CO2rtcoef_fy2_x_vissr.dat05/10/2016
10/11/2016

24/03/2017
scaercoef_fy2_x_vissr.datsccldcoef_fy2_x_vissr.dat
VTPR7 / 8O3 / O3, CO2rtcoef_noaa_x_vtpr1.dat05/10/2016
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.


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
  • 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

SensorTrace gasesFilenameDate of file creationAssociated aerosol coef filenameAssociated cloud coef filename
(A)ATSR*O3, CO2rtcoef_ers_x_atsr.dat
rtcoef_envisat_1_atsr.dat
28/11/2016scaercoef_ers_x_atsr.dat
scaercoef_envisat_1_atsr.dat
sccldcoef_ers_x_atsr.dat
sccldcoef_envisat_1_atsr.dat
AATSR-shifted
Info on AATSR 12 um anomaly
O3, CO2rtcoef_envisat_1_atsr-shifted.dat28/11/2016scaercoef_envisat_1_atsr-shifted.datsccldcoef_envisat_1_atsr-shifted.dat
ABIO3, CO2rtcoef_goes_xx_abi.dat28/11/2016scaercoef_goes_xx_abi.datsccldcoef_goes_xx_abi.dat
AHIO3, CO2rtcoef_himawari_x_ahi.dat28/11/2016scaercoef_himawari_x_ahi.datsccldcoef_himawari_x_ahi.dat
ASTERO3, CO2rtcoef_eos_1_aster.dat28/11/2016scaercoef_eos_1_aster.datsccldcoef_eos_1_aster.dat
AVHRRO3, CO2rtcoef_metop_x_avhrr.dat
rtcoef_noaa_xx_avhrr.dat
28/11/2016scaercoef_noaa_xx_avhrr.dat
scaercoef_metop_x_avhrr.dat
scaercoef_noaa_xx_avhrr.dat
scaercoef_metop_x_avhrr.dat
FCIO3, CO2rtcoef_mtg_1_fci.dat04/01/2017scaercoef_mtg_1_fci.datsccldcoef_mtg_1_fci.dat
GMS imagerO3, CO2rtcoef_gms_x_imager.dat02/03/2017scaercoef_gms_x_imager.datsccldcoef_gms_x_imager.dat
GOES imagerO3, CO2rtcoef_goes_xx_imager.dat28/11/2016scaercoef_goes_xx_imager.datsccldcoef_goes_xx_imager.dat
INSAT-3D(R) imagerO3, CO2rtcoef_insat_x_imager.dat28/11/2016scaercoef_insat_x_imager.datsccldcoef_insat_x_imager.dat
IRASO3, CO2rtcoef_fy3_1_iras.dat28/11/2016scaercoef_fy3_1_iras.datsccldcoef_fy3_1_iras.dat
LI**O3, CO2rtcoef_mtg_1_li.dat25/01/2017--
MetImageO3, CO2rtcoef_metopsg_1_metimage.dat28/11/2016scaercoef_metopsg_1_metimage.datsccldcoef_metopsg_1_metimage.dat
MIO3, CO2rtcoef_coms_1_mi.dat28/11/2016scaercoef_coms_1_mi.datsccldcoef_coms_1_mi.dat
MODISO3, CO2rtcoef_eos_x_modis.dat28/11/2016scaercoef_eos_x_modis.datsccldcoef_eos_x_modis.dat
MODIS shifted spectral responseO3, CO2rtcoef_eos_x_modis-shifted.dat28/11/2016scaercoef_eos_x_modis-shifted.datsccldcoef_eos_x_modis-shifted.dat
MTSAT imagerO3, CO2rtcoef_mtsat_x_imager.dat28/11/2016scaercoef_mtsat_x_imager.datsccldcoef_mtsat_x_imager.dat
OLCI***O3, CO2rtcoef_sentinel3_1_olci.dat06/01/2017--
OLIO3, CO2rtcoef_landsat_8_oli.dat28/11/2016scaercoef_landsat_8_oli.datsccldcoef_landsat_8_oli.dat
SEVIRI****O3rtcoef_msg_x_seviri_o3.dat28/11/2016scaercoef_msg_x_seviri.datsccldcoef_msg_x_seviri.dat
SEVIRIO3, CO2rtcoef_msg_x_seviri.dat28/11/2016As aboveAs above
SLSTRO3, CO2rtcoef_sentinel3_1_slstr.dat28/11/2016scaercoef_sentinel3_1_slstr.datsccldcoef_sentinel3_1_slstr.dat
VIIRSO3, CO2rtcoef_jpss_0_viirs.dat28/11/2016scaercoef_jpss_0_viirs.datsccldcoef_jpss_0_viirs.dat
VISSRO3, CO2rtcoef_fy2_x_vissr.dat28/11/2016scaercoef_fy2_x_vissr.datsccldcoef_fy2_x_vissr.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.


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 for all MW sensors – extract to rtcoef_rttov12/rttov7pred54L/
  • Files including band-correction coefficients for selected MW sensors – extract to rtcoef_rttov12/rttov7pred54L/, but note that this will OVERWRITE existing non-band-correction coefficient files.
  • Band-correction coefficients are included only for sensors where they have a significant impact on radiances: SSMT2, SSMI/S, HSB, GMI, MWHS, MWHS2, GMI, ATMS, SAPHIR, MTVZAGY, ICI, MWI, MWS, AMSU-B and SCAMS. Note that the impact on brightness temperatures is negligible.
  • RTTOV-SCATT Mietable files are linked in the table below – extract to rtcoef_rttov12/mietable/ (NB these are identical to the RTTOV v11 files)
SensorZeeman
compatible
Band-correction
coefficients
available
FilenameDate of file
creation
Associated Mietable
filename
AltiKaNNrtcoef_saral_1_altika.dat26/05/2016mietable_saral_altika.dat
AMRNNrtcoef_jason_2_amr.dat26/05/2016-
AMSR-ENNrtcoef_eos_2_amsre.dat26/05/2016mietable_eos_amsre.dat
AMSR2NNrtcoef_gcom-w_1_amsr2.dat26/05/2016mietable_gcom-w_amsr2.dat
AMSU-ANNrtcoef_noaa_xx_amsua.dat
rtcoef_metop_x_amsua.dat
rtcoef_eos_2_amsua.dat
26/05/2016mietable_noaa_amsua.dat
mietable_metop_amsua.dat
mietable_eos_amsua.dat
AMSU-BNYrtcoef_noaa_xx_amsub.dat
26/05/2016mietable_noaa_amsub.dat
ATMSNYrtcoef_jpss_0_atms.dat26/05/2016mietable_jpss_atms.dat
COWVRNNrtcoef_ors_6_cowvr.dat18/05/2017-
GMINYrtcoef_gpm_1_gmi.dat26/05/2016mietable_gpm_gmi.dat
HSBNYrtcoef_eos_2_hsb.dat26/05/2016-
ICI*NYrtcoef_metopsg_1_ici.dat26/05/2016-
MADRASNNrtcoef_meghatr_1_madras.dat26/05/2016mietable_meghatr_madras.dat
MIRASNNrtcoef_smos_1_miras.dat18/05/2017-
MHSNNrtcoef_noaa_xx_mhs.dat
rtcoef_metop_x_mhs.dat
26/05/2016mietable_noaa_mhs.dat
mietable_metop_mhs.dat
MSUNNrtcoef_noaa_xx_msu.dat26/05/2016-
MTVZA-GYNYrtcoef_meteor-m_2_mtvzagy.dat26/05/2016mietable_meteor-m_mtvzagy.dat
MWHSNYrtcoef_fy3_x_mwhs.dat26/05/2016mietable_fy3_mwhs.dat
MWHS2NYrtcoef_fy3_x_mwhs2.dat26/05/2016
13/01/2017
mietable_fy3_mwhs2.dat
MWINYrtcoef_metopsg_1_mwi.dat26/05/2016mietable_metopsg_mwi.dat
MWRNYrtcoef_ers_x_mwr.dat
rtcoef_envisat_1_mwr.dat
26/05/2016mietable_ers_mwr.dat
mietable_envisat_mwr.dat
MWRINNrtcoef_fy3_x_mwri.dat26/05/2016
13/01/2017
mietable_fy3_mwri.dat
MWSNYrtcoef_metopsg_1_mws.dat26/05/2016mietable_metopsg_mws.dat
MWTSNNrtcoef_fy3_x_mwts.dat26/05/2016mietable_fy3_mwts.dat
MWTS2NNrtcoef_fy3_x_mwts2.dat26/05/2016
13/01/2017
mietable_fy3_mwts2.dat
SAPHIRNYrtcoef_meghatr_1_saphir.dat26/05/2016mietable_meghatr_saphir.dat
SCAMSNYrtcoef_nimbus_6_scams.dat11/01/2017-
SMMRNNrtcoef_nimbus_7_smmr.dat26/05/2016-
SSM/INNrtcoef_dmsp_xx_ssmi.dat26/05/2016mietable_dmsp_ssmi.dat
SSMISNYrtcoef_dmsp_xx_ssmis.dat26/05/2016mietable_dmsp_ssmis.dat
SSMIS Zeeman (84L)YNrtcoef_dmsp_xx_ssmis_zeeman.dat11/01/2017As above
SSM/T2NYrtcoef_dmsp_xx_ssmt2.dat26/05/2016-
TMINNrtcoef_trmm_1_tmi.dat26/05/2016mietable_trmm_tmi.dat
WindsatNNrtcoef_coriolis_1_windsat.dat26/05/2016mietable_coriolis_windsat.dat

* ICI coefficients are preliminary: channel specifications may change. Work is planned to validate the spectroscopic data used at frequencies above 200GHz.

Updated Mie tables (10/09/2013):
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:

  • Liu, G. (2008). A database of microwave single-scattering properties for nonspherical ice particles. Bulletin of the American Meteorological Society, 89(10), 1563-1570.
  • 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

Reference profiles and regression limits

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 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.