The ``unformatted'' binary file is compact, fairly complete, and (in comparison to ASCII output files) is efficiently written from FORTRAN. However, binary files are not compatible between different computer architectures if written by ``unformatted'' WRITE from FORTRAN. Thus, you have to process the data on the same computer architecture that was used for the DDSCAT calculations. We provide an option of using netCDF with DDSCAT. The netCDF library defines a machine-independent format for representing scientific data. Together, the interface, library, and format support the creation, access, and sharing of scientific data. For more information see http://www.unidata.ucar.edu/packages/netcdf.
Several major graphics packages (for example IDL) have adopted netCDF as a standard for data transport. For this reason, and because of strong and free support of netCDF over the network by UNIDATA, we have implemented a netCDF interface in DDSCAT. This may become the method of choice for binary file storage of output from DDSCAT.
After the initial ``learning curve'' netCDF offers many advantages:
The public-domain netCDF software is available for many operating systems from http://www.unidata.ucar.edu/packages/netcdf . The steps necessary for enabling the netCDF capability in DDSCAT.5a\ are listed above in §5.4. Once these have been successfully accomplished, and you are ready to run DDSCAT to produce netCDF output, you must choose either the ALLCDF or ORICDF option in ddscat.par; ALLCDF will result in a file which will include the Mueller matrix for every wavelength, particle size, and orientation, whereas ORICDF will result in a file limited to just the orientational averages for each wavelength and target size.