The latest version of RTTOV is RTTOV v12.

RTTOV v11 was released in May 2013 and the last update was v11.3, released in September 2015. RTTOV v11 may be obtained by adding RTTOV to your list of software preferences once you have registered and logged in.

Coefficients, emissivity and BRDF atlas data files are available separately on the RTTOV downloads page.

Please look at the list of known bugs as the official release package does not contain any updates or fixes listed there.

Existing RTTOV v11.2 users should also read this document which describes issues related to the choice of input gas units in v11.2 and earlier and also the bugs discovered in the coefficient generation code which has resulted in all v7/v8 predictor coefficient files being updated for v11.3.

RTTOV v11 documentation

Requirements for RTTOV 11

  • Computer running Linux/Unix or Apple Mac OS X
  • Fortran 90 compiler (e.g. gfortran)
  • gzip compression utility
  • GNU make utility
  • 500+ MB free disk space required for full install (including bundled coefficients and test and reference data). Additional space is required for larger coefficient files that are not included with the RTTOV package.

Installing RTTOV v11.3

To compile RTTOV v11.3, create a new directory for the package. For example:

$ mkdir ~user/rttov11
$ cd ~user/rttov11

Copy the compressed RTTOV package file (rttov113.tar.gz or rttov113.tar.xz) into this new top-level directory and extract the contents, for example:

$ tar xf rttov113.tar.gz

RTTOV can be compiled without any external dependencies. However to make use of all functionality you should edit the file build/Makefile.local before compiling with the location of your HDF5 installation. Alternatively you can specify the location of your NetCDF installation which will at least enable the use of the land surface emissivity and BRDF atlases.

RTTOV v11.3 can be compiled using an interactive script:

$ cd src
$ ../build/rttov_compile.sh

Alternatively you can compile manually as for v11.2: see the user guide for details.

Upgrading to RTTOV v11.3 from v11.x

Existing RTTOV v11.2 users can upgrade to v11.3 by downloading the update package rttov113_update.tar.gz and following the instructions below. Information about v11.3 can be found in the readme.txt.

Copy the update package into your existing RTTOV v11.2 directory, delete some files which are no longer necessary, and then unpack the tarball:

cd ~user/rttov11 [your top-level RTTOV v11.2 directory]
rm -f src/other/us76_to_hdf5.F90
rm -f src/test/rttov_zutility_test.F90
rm -f src/test/test_weighting_fn_dev.F90
rm -fr rttov_test/*
tar zxf rttov113_update.tar.gz

RTTOV v11.3 can be compiled just as for v11.2. However a new interactive script is available which may make compilation easier (see above or see the user guide for full instructions). The update package contains updated test reference data so you can verify your build.

RTTOV v11.1 users can upgrade to v11.3 by first updating to RTTOV v11.2 and then applying the update package described above. To update from v11.1 to v11.2, download rttov112_update.tar.gz and follow the instructions in the associated readme_v112.txt.

Important notes for v11.3

  • If you compile RTTOV v11.3 against the HDF5 library and you use the emissivity and/or BRDF atlases, then you must use the new HDF5 format BRDF and IR emissivity atlas files. In this case there is no need to specify a NetCDF installation in build/Makefile.local (it would be ignored). However if you do not compile with HDF5 support you can still compile against the NetCDF library and use the NetCDF versions of the atlas files.
  • The BRDF atlas in v11.3 has improved treatment of snow reflectances. This has required the eigenvector data file to be updated. If you are compiling with HDF5 the new file is included with the new HDF5 format files. If you are compiling with NetCDF you must download the new NetCDF format BRDF eigenvector file.
  • If you build RTTOV with HDF5 support and you do not use the new compilation script to compile RTTOV (see above) then you must regenerate the Makefiles to include the RTTOV HDF5 code after the update before recompiling:
    cd src
    ../build/Makefile.PL RTTOV_HDF=1
  • The majority of coefficient files have been regenerated for RTTOV v11.3 as explained in this document. These updated coefficients include bug fixes in the coefficient generation and users are recommended to use the new files. The test reference data was created using these new coefficient files. The update package does not include any coefficient files.
  • The tests for hyperspectral sounders in the test suite all assume HDF5 format coefficient files. The only exceptions are the tests called by the test_coef_io.sh script which assume ASCII format coefficient files. Note that it is not necessary to run every test script to verify your installation: it is sufficient to run just test_rttov11.sh which runs tests only for ASCII (non-hi-res IR) coefficient files. See the user guide for more information about testing RTTOV.
  • The RTTOV libraries no longer have the minor version number in the filename: for example librttov11.2.0_main.a becomes librttov11_main.a.