RTTOV v12 Code Updates and Known Issues

RTTOV v12 Code Updates

Updates and bug fixes to RTTOV v12 will be published here.

Known bugs and issues

Please report any bugs you find in RTTOV using the NWP SAF Feedback Form. The official release package doesn’t contain the bug fixes or updates listed here so you should apply any fixes provided below.

Show/Hide the table of known bugs in RTTOV v12.1.

DateType/StatusDescription
16/08/2017Bug - fixedThe ocean and coastal water reflectance spectra from the USGS Digital Spectral Library have been incorrectly sampled in wavenumber space leading to incorrect fixed reflectances being used for water in the sea surface BRDF model (see the RTTOV v12 user guide for details) and incorrect fixed reflectances for sea-surface profiles being returned by the BRDF atlas. The "old" (incorrect) and "new" (corrected) spectra can be seen in the following plots (note that the precision of the data has also been increased in the corrected spectra):
- ocean water spectrum
- coastal water spectrum

For the ocean water case the largest impact on top-of-atmosphere simulated reflectances is up to order 0.01 in channels around 0.4-0.55µm while for other channels the impact is of order 0.001.

A code fix is available: copy this updated source file to src/main/ and recompile RTTOV.

This update changes the test output for test_fwd.sh, test_rttov12.sh, test_solar.sh and test_brdf_atlas.sh. If you wish to update the reference data for these test scripts download and extract this tarball in the rttov_test/ directory.
11/08/2017Bug - fixedMinor bug in pyrttov (the Python RTTOV wrapper) which causes a fatal error if the Atlas class is initialised with the verbose argument set to False.

A code fix is available: copy the file (right-click and "Save As...") __init__.py_ and rename it to wrapper/pyrttov/__init__.py
11/08/2017Bug - fixedArray bounds errors occur with the BRDF atlas if the latitude is set to exactly -90 degrees or if the longitude is set to exactly 180 degrees.

A code fix is available: copy this updated source file to src/brdf_atlas/ and recompile RTTOV.
07/07/2017Bug - fixedArray bounds errors occur with the CAMEL atlas if the latitude is set to exactly -90 degrees or if the surface type is set to land and the atlas has no data for the given lat/lon.

A code fix is available: copy this updated source file to src/emis_atlas/ and recompile RTTOV.
07/07/2017Bug - fixedAn array bounds error occurs with the UWIRemis atlas if the latitude is set to exactly -90 degrees.

A code fix is available: copy this updated source file to src/emis_atlas/ and recompile RTTOV.
08/06/2017Bug - fixedAn array bounds error occurs if the TELSEM2 atlas is called for a profile with a latitude of exactly 90 degrees.

A code fix is available: copy this updated source file to src/emis_atlas/ and recompile RTTOV (NB this includes the bug fix below dated 27/02/2017).
17/03/2017Bug - fixedIf you carry out visible/IR aerosol simulations using the predefined particle types and you do not use the RTTOV interpolator (i.e. profiles are input on coefficient levels) then the relative humidity calculation is not carried out. This will result in errors in the calculation of optical properties of those aerosol types which vary with humidity. There is no problem if you are using the RTTOV interpolator.

A code fix is available: extract the file rttov121_bugfix_20170317_aerosol.tar.gz in the src/main/ directory and recompile RTTOV.
27/02/2017Bug - fixedThe TELSEM2 emissivity atlas returns emissivity values slightly greater than one for some locations with climatological sea ice for channels at 85GHz and greater. If these values are passed directly into RTTOV v12, it will fail with an error saying there are invalid emissivity values.

This can be avoided either by explicitly capping the emissivities from the atlas at 1. in your own code (e.g. "emis = MIN(1., emis)") or by downloading this updated source file to src/emis_atlas/ and recompiling RTTOV (NB this includes the bug fix above dated 08/06/2017).