RadSim Code Updates and Known Issues

RadSim Code Updates

Updates and bug fixes to the Radiance Simulator for all versions since v2.0 are published here.

Known bugs and issues

Please report any bugs you find in RadSim using the NWP SAF Feedback Form. The official release packages do not contain the bug fixes or updates listed here so you should apply any fixes provided below. Bugs in earlier versions have been fixed in later versions unless otherwise stated.

DateType/StatusDescription
24/03/2025Functionality updateAffects: reading more recent ECMWF model data in netCDF format (v3.x, v2.2).

Issue: the file format has changed slightly such that the existing code is not compatible with more recent netCDF files.

Fix:
For v3.2 and v3.1 download and extract this tarball containing updated source files to src/code/main/ and recompile RadSim. Note that pre-existing netCDF files are still supported: this update adds compatibility with recent files.

For updates for v3.0 and v2.2, please contact the help desk.
02/09/2024Bug - fixedAffects: the radsim_geo_obs.py script (v3.x).

Issue: the script does not handle longitudes correctly, so for some "geo obs data files" (notably the himawari file provided on the RadSim website) it fails with an error reporting non-monotonic longitudes.

Fix: download this updated version of the script (applies to RadSim 3.x).
05/07/2024Bug - fixedAffects: flagging of bad emissivities and BRDFs from the emissivity/BRDF atlases (v3.x, v2.2).

Issue: for emissivities, RadSim sets flags for bad emissivities even when no thermal channels are being simulated. For BRDFs, an indexing error means that bad BRDFs may be incorrectly flagged if running with a subset of instrument channels (there is no issue if all sensor channels are simulated).

Fix:
For v3.2 and v3.1 download this updated source file to src/code/main/ and recompile RadSim.

For v3.0 download this updated source file to src/code/main/ and recompile RadSim.

For v2.2 download this updated source file to src/code/main/ and recompile RadSim.

DateType/StatusDescription
24/11/2022Bug - fixedAffects: ECMWF data in netCDF format (v3.1, v3.0, v2.2).

Issue: RadSim checks that the data are on a regular lat/lon grid. In some circumstances (identified when using data on a 0.1 degree lat/lon grid) rounding errors cause RadSim to falsely report an irregular grid and to stop running because the tolerance used for this check is exceeded. If RadSim is running fine for you then there is no problem.

Fix:
For v3.1 download this updated source file to src/code/main/ and recompile RadSim.

For v3.0 download this updated source file to src/code/main/ and recompile RadSim.

For v2.2 download this updated source file to src/code/main/ and recompile RadSim.

DateType/StatusDescription
09/12/2021Bug - fixedAffects: footprint simulations (v3.0 only).

Issue: when observations lie exactly on grid points, the footprint calculation can sometimes result in numerical errors due to rounding.

This bug has been fixed: download this updated source file to src/code/main/ and recompile RadSim.
03/12/2021Bug - fixedAffects: the interpreter specified in the radsim_geo_obs.py script (v3.0 only).

Issue: the script contains a typo which means it cannot be executed directly. There is no problem if it is executed using:
$ python radsim_geo_obs.py

Fix: download this updated version of the script.

NB This update now includes the fix described above under RadSim v3.2 dated 02/09/2024.