CHAPTER 4: How to use 
?
4.1 General
After SCIATRAN has been sucessfully installed the program SCIATRAN_*.exe (* = SUN, IBM, or CRAY) can be easily executed by typing, for example on SUN,
SCIATRAN_SUN.exein directory ~/Execute/ or by invoking SCIATRAN_SUN.exe by using the complete path to ~/Execute/ whilst being in a different directory.
Before starting the program the user has to manually adjust several user ASCII interface files in order to specify the viewing geometry, wavelength grid etc. These user interface files are described in the next section.
4.2 User interface files
Via seven user interface files the user can control viewing geometry, atmospheric composition, surface albedo etc.:
| control.inp | Main user interface file |
| control2.inp | User interface file (``permanent'' settings) |
| esft.inp | ESFT data base specification |
| low_aer.inp | LOWTRAN aerosol scenario specification |
| scia_aer.inp | SCIATRAN aerosol scenario specification |
| xsections.inp | Absorption cross section specification |
| gt_net.inp | Height grid specification |
The main user input files are control.inp and the aerosol scenario input file (filename, incl. path, to be specified in control.inp).
Only the two user input files control.inp and control2.inp (and also esft.inp, which normally does not have to be changed) have fixed filenames and have to be located in the current directory.
Note that the filenames of the last four files given in the table above (i.e. all files except the ''control''-files and esft.inp) are not fixed but have to be specified by the user in control.inp. For each interface file a sample has been included in this user's guide with the same filename as given above. These sample files contain detailed comments in order to allow the user to properly make use of the program and to understand its capabilities.
The structure of these user interface files is as follows:
All user input files contain comment lines (lines beginning with
``!''), empty lines, lines containing key ''words'' (for
example:
``Do automatic matrix inversion'') and
subsequent lines of input parameters (for example: ``F'' for
``false''). Only those lines containing the input parameters have to
be modified by the user. The parameters are usually in the last line
of each paragraph (some exceptions exist, for example the
specification of the spectral segments).
Please note that all comment lines (i.e. lines beginning with ``!'') and all empty lines can be removed. It is sufficient to have sequences of one line containing the key word followed by (in most cases) one line containing the user selected settings. In general it is even possible to change the order of this sequence. This is stricly true for the main user input file control.inp, except for the cloud section, which requires a fixed relative order.
Some examples of control.inp files (control.t0i, i = 1,...,4, control.ref) are included in ~/tests/.
4.3 Example screen output
If ``Detailed log file'' has been set true in control.inp the following screen output appears for a typical program run (including some notes or with several consecutive (similar) lines removed marked with ``...''):
See the screen output in file screen.out in a new window or in this window.