libRadtran is freely available under the [[http://www.libradtran.org/doc/COPYING|GNU General Public License]]. To install libRadtran on a Unix type system follow the [[http://www.libradtran.org/doc/README.unpacking|unpacking instructions]] and the [[http://www.libradtran.org/doc/INSTALL|installation instructions]]. For the impatient: === 1. Get the distribution === Here is the [[http://www.libradtran.org/download/libRadtran-2.0.5.tar.gz|most recent version 2.0.5]] from July 25, 2023. [[http://www.libradtran.org/dowload/history/|Older versions]] are also still available (if asked for username and password, please try libRadtran for both). If you download the package we ask you to send us a short eMail to let us know that you use the model. We have created a mailing list of libRadtran users in order to notify them of additions, changes, and bug fixes on an irregular basis. === 2. Unpack the distribution === gzip -d libradtran-x.yy.tar.gz tar -xvf libradtran-x.yy.tar where x.yy is the version number. === 3. Compile the distribution === cd libRadtran-x.yy ./configure make === 4. Test the program === make check (make sure to use GNU make) === 5. Get additional modules if required === * [[http://www.meteo.physik.uni-muenchen.de/~libradtran/lib/exe/fetch.php?media=download:optprop_v2.1.tar.gz|Optical properties of water clouds, ice clouds and OPAC aerosols in netcdf format]]. Please untar these data in the libRadtran directory. Note that all optical properties data has now been merged into one tar file. If you need the older data, please check [[http://www.libradtran.org/download/history/|here]]. The original OPAC aerosol data are available [[https://doi.org/10.5281/zenodo.7275005|here]]. * [[http://www.meteo.physik.uni-muenchen.de/~libradtran/lib/exe/fetch.php?media=download:ic_yang2013.tar.gz|Optical properties for ice cloud parameterization based on single scattering data by P. Yang et al., 2013]] (updated March 22, 2016). Please untar these data in the libRadtran directory. * [[http://www.meteo.physik.uni-muenchen.de/~libradtran/lib/exe/fetch.php?media=download:reptran_2017_all.tar.gz|Data for the REPTRAN absorption parameterization]]. Updated December 24, 2017! Please untar these data in the libRadtran directory. Parameterization data for bands as well as for satellite channels is included. * An example for a line-by-line absorption cross section profile for the oxygen A-Band around 760 nm; [[http://www.libradtran.org/download/UVSPEC.O2A.afglms.cdf|UVSPEC.O2A.afglms.cdf]] can be used as molecular_tau_file, see the libRadtran documentation of this option. * For the brave and strong, we also offer [[http://www.libradtran.org/download/molecular_tau/index.html|line-by-line absorption data for the spectral range 500 nm - 100 micron]]. Check the [[http://www.libradtran.org/download/molecular_tau/README|README]]!. * Scripts to compute line-by-line absorption coefficients: [[http://atmos.eoc.dlr.de/tools/Py4CAtS/|Py4CATS]] * [[http://www.libradtran.org/download/kurudz_full.tar.gz|Full resolution extraterrestrial spectrum]] by Kurucz et al. (1992), 100 MByte! * [[https://mopsmap.net|MOPSMAP - a versatile tool for the modeling of aerosol optical properties]] - a web interface to generate aerosol optical properties in the netcdf format as required for libRadtran. The user may define size and shape distribution, refractive index, etc. or to use pre-defined aerosol types. The package is described in [[https://www.geosci-model-dev.net/11/2739/2018/|Gasteiger and Wiegner, 2018]]. === 6. Required software to build libRadtran === The following software is required to successfully compile, link and run all of the libRadtran tools: * GNU make. The compilation might work with other make programs, but usually it doesn't. * The GNU C compiler (gcc). Other compilers might also work. * A Fortran compiler that is compatible with the C compiler. If a C compatible Fortran compiler is not available, f2c will do the job. * Flex - The Fast Lexical Analyzer. Is usually available for all flavours of Linux, under Mac, and for cygwin, but not necessarily installed by default. You may have to select installation of flex manually. * The Perl programming language, version 5.004 or later, is required to run the automatic test. * The netcdf library, including development package. * The GNU Scientific Library (GSL), including development package. That's it. The example files and the [[:documentation]] should give you enough knowledge to get started. Users of Windows 95/98/NTXP/Vista/7 systems are asked to consult the [[http://www.libradtran.org/doc/README.windows|installation of libRadtran under Windows]] instructions. Compilation under Windows is possible with only little more effort than on a Unix system. Please notice that we haven't updated this README (essentially because of laziness) because the Cygwin Stuff changes continuously - but we are sure that you will find your way! To test libRadtran on Windows you may also try the [[http://www.meteo.physik.uni-muenchen.de/~libradtran/lib/exe/fetch.php?media=download:libradtran-2.0-virtualbox.exe|Virtual Box]]. You find detailed installation instructions [[ http://www.meteo.physik.uni-muenchen.de/~libradtran/lib/exe/fetch.php?media=download:run_libradtran_virtual_machine.pdf|here]]. For users of Windows 10 the [[https://en.wikipedia.org/wiki/Windows_Subsystem_for_Linux|Windows Subsystem for Linux]] is an option which allows installing libRadtran inside the subsystem. When using this subsystem be aware of the differences between Windows and Linux, e.g., with respect to pathnames (case-sensitivity, treatment of spaces, slash vs backslash). === 7. Miscellaneous === The standalone version of [[http://www.libradtran.org/download/cdisort-2.1.3.tar.gz|cdisort 2.1.3]] (the C language version of DISORT provided by Tim Dowling, updated July 25, 2013) may be obtained as well. See the included HOW_TO file for tips on installation and usage in a C environment. In publications, please cite Buras et al (2011, J. Quant. Spectr. Ra. Tran. 112, 2028-2034, doi:10.1016/j.jqsrt.2011.03.019).